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Zhang Y, Edwards SA, House M. Cerclage prevents ascending intrauterine infection in pregnant mice. Am J Obstet Gynecol 2024; 230:555.e1-555.e8. [PMID: 37816485 PMCID: PMC10999506 DOI: 10.1016/j.ajog.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 09/28/2023] [Accepted: 10/03/2023] [Indexed: 10/12/2023]
Abstract
BACKGROUND The treatment for cervical insufficiency is cerclage surgery. Although cerclage is a common therapy for prevention of preterm birth, there is no consensus about its mechanism of efficacy. Previous investigators have hypothesized that cerclage prevents preterm birth by improving the cervical barrier to ascending infection. However, this hypothesis is difficult to study in human pregnancy. OBJECTIVE In a mouse model of ascending infection, we hypothesized that a cerclage improves the cervical barrier leading to decreased ascending intrauterine infection and inflammation. An abdominal cerclage was studied because a vaginal cerclage is not feasible in mice. STUDY DESIGN To perform an abdominal cerclage, laparotomy was performed on timed, pregnant C57BL/6 mice on gestational day 10 (E10). A 6-0 silk suture was placed around the cervix just below the junction of the 2 uterine horns. Sham controls received the same surgery, but no cerclage was placed. To track ascending infection nonpathogenic E coli K12 was genetically modified to express bioluminescence. On E15, bioluminescent E coli K12 (20 μL of 1×109 bacteria) was inoculated into the vagina. Whole-body bioluminescence imaging was performed 0.5 hours and 24 hours after inoculation. To assess intrauterine inflammation, pathogenic E coli K1 was used. On E15, bacterial inoculums of E coli K1 (20 μL of 1×104 bacteria) were vaginally administered. Samples of uterus, placenta, and fetal membranes were collected 24 hours after inoculation. Gene expression of inflammation-related proteins was compared between 3 groups: (1) sham control surgery + inoculation of phosphate-buffered saline (PBS), (2) sham control surgery + inoculation of E coli K1, and (3) cerclage surgery + inoculation of E coli K1. RESULTS Abdominal cerclage was well tolerated. No cases of preterm birth were seen following abdominal cerclage. Whole-body bioluminescent imaging performed 0.5 hours post inoculation showed a strong luminescence signal in the vaginal region of mice in both control and experimental groups indicating successful bacteria inoculation. Twenty-four hours after inoculation, bioluminescent signal was seen ascending into the uterine horns in all control mice. However, in mice with abdominal cerclages, no bioluminescent signal was seen after 24 hours. When the reproductive tissues were imaged separately in control mice, strong bioluminescence signal was detected in the placenta, fetal membranes, and uterus. Gene expression studies showed that cerclage significantly decreased the expression of inflammatory proteins induced by E coli K1 in the uterus, placenta, and fetal membranes. CONCLUSION In this mouse model of ascending intrauterine infection, abdominal cerclage prevented ascending infection of E coli. In addition, abdominal cerclage prevented expression of inflammatory cytokines in the uterus, placenta, and membranes of mice. The study provides evidence for a potential mechanism of cerclage success in human pregnancy.
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Affiliation(s)
- Yali Zhang
- Mother Infant Research Center, Tufts Medical Center, Boston, MA
| | - Skye A Edwards
- Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Michael House
- Mother Infant Research Center, Tufts Medical Center, Boston, MA; Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Tufts Medical Center, Boston, MA.
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2
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Mercado-Evans V, Mejia ME, Zulk JJ, Ottinger S, Hameed ZA, Serchejian C, Marunde MG, Robertson CM, Ballard MB, Ruano SH, Korotkova N, Flores AR, Pennington KA, Patras KA. Gestational diabetes augments group B Streptococcus infection by disrupting maternal immunity and the vaginal microbiota. Nat Commun 2024; 15:1035. [PMID: 38310089 PMCID: PMC10838280 DOI: 10.1038/s41467-024-45336-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 01/19/2024] [Indexed: 02/05/2024] Open
Abstract
Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. Using a murine GDM model of GBS colonization and perinatal transmission, we find that GDM mice display greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing reveals differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM immune disruptions include reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered maternofetal cytokines. Lastly, we observe distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Here, we show a model of GBS dissemination in GDM hosts that recapitulates several clinical aspects and identifies multiple host and bacterial drivers of GBS perinatal disease.
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Affiliation(s)
- Vicki Mercado-Evans
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Marlyd E Mejia
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jacob J Zulk
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Samantha Ottinger
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zainab A Hameed
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Camille Serchejian
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Madelynn G Marunde
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Clare M Robertson
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Mallory B Ballard
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Simone H Ruano
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Natalia Korotkova
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Anthony R Flores
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, UTHealth Houston, Children's Memorial Hermann Hospital, Houston, TX, USA
| | - Kathleen A Pennington
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kathryn A Patras
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX, 77030, USA.
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3
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Cai X, Yang S, Peng Y, Tan K, Xu P, Wu Z, Kwan KY, Jian J. Regulation of PhoB on biofilm formation and hemolysin gene hlyA and ciaR of Streptococcus agalactiae. Vet Microbiol 2024; 289:109961. [PMID: 38147806 DOI: 10.1016/j.vetmic.2023.109961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 12/08/2023] [Accepted: 12/19/2023] [Indexed: 12/28/2023]
Abstract
PhoB is a response regulator protein that plays a key role in the PhoBR two-component signal transduction system. In this study, we used transcriptome and proteomics techniques to evaluate the detect the gene network regulated by PhoB of Streptococcus agalactiae. The results showed that expression of biofilm formation and virulence-related genes were changed after phoB deficiency. Crystal violet and CLSM assay confirmed that the deletion of the phoB increased the thickness of S. agalactiae biofilm. The results of lacZ reporter and the bacterial one-hybridization method showed that PhoB could directly bind to the promoter regions of hemolysin A and ciaR genes but not to the promoter regions of cylE and hemolysin III. Through the construction of an 18-base pair deoxyribose nucleic acid (DNA) random fragment library and the bacterial one-hybridization system, it was found that the conservative sequence of PhoB binding was TTGGAGAA(G/T). Our research has uncovered the virulence potential of the PhoBR two-component system of S. agalactiae. The findings of this study provide the theoretical foundation for in-depth research on the pathogenic mechanism of S. agalactiae.
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Affiliation(s)
- Xiaohui Cai
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Shaoyu Yang
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Yinhui Peng
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China; College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524088, China
| | - Kianann Tan
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Peng Xu
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Zaohe Wu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524088, China
| | - Kit Yue Kwan
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China.
| | - Jichang Jian
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524088, China.
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4
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Bhavana VH, Hillebrand GH, Gopalakrishna KP, Rapp RA, Ratner AJ, Tettelin H, Hooven TA. A group B Streptococcus indexed transposon mutant library to accelerate genetic research on an important perinatal pathogen. Microbiol Spectr 2023; 11:e0204623. [PMID: 37933989 PMCID: PMC10714824 DOI: 10.1128/spectrum.02046-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/29/2023] [Indexed: 11/08/2023] Open
Abstract
IMPORTANCE Group B Streptococcus (GBS) is a significant global cause of serious infections, most of which affect pregnant women, newborns, and infants. Studying GBS genetic mutant strains is a valuable approach for learning more about how these infections are caused and is a key step toward developing more effective preventative and treatment strategies. In this resource report, we describe a newly created library of defined GBS genetic mutants, containing over 1,900 genetic variants, each with a unique disruption to its chromosome. An indexed library of this scale is unprecedented in the GBS field; it includes strains with mutations in hundreds of genes whose potential functions in human disease remain unknown. We have made this resource freely available to the broader research community through deposition in a publicly funded bacterial maintenance and distribution repository.
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Affiliation(s)
- Venkata H. Bhavana
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Gideon H. Hillebrand
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
| | | | - Rebekah A. Rapp
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- The Ellis School, Pittsburgh, Pennsylvania, USA
| | - Adam J. Ratner
- Department of Pediatrics, New York University, New York, New York, USA
- Department of Microbiology, New York University, New York, New York, USA
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
- Richard King Mellon Institute for Pediatric Research, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania, USA
- UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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5
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Vancolen S, Ayash T, Allard MJ, Sébire G. Sex-Specific Dysconnective Brain Injuries and Neuropsychiatric Conditions such as Autism Spectrum Disorder Caused by Group B Streptococcus-Induced Chorioamnionitis. Int J Mol Sci 2023; 24:14090. [PMID: 37762401 PMCID: PMC10531534 DOI: 10.3390/ijms241814090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
Global health efforts have increased against infectious diseases, but issues persist with pathogens like Group B Streptococcus (GBS). Preclinical studies have elaborated on the mechanistic process of GBS-induced chorioamnionitis and its impact on the fetal programming of chronic neuropsychiatric diseases. GBS inoculation in rodents demonstrated the following: (i) silent and self-limited placental infection, similar to human chorioamnionitis; (ii) placental expression of chemokines attracting polymorphonuclear (PMN) cells; (iii) in vitro cytokine production; (iv) PMN infiltration in the placenta (histologic hallmark of human chorioamnionitis), linked to neurobehavioral impairments like cerebral palsy and autism spectrum disorders (ASD); (v) upregulation of interleukin-1β (IL-1β) in the placenta and fetal blood, associated with higher ASD risk in humans; (vi) sex-specific effects, with higher IL-1β release and PMN recruitment in male placenta; (vii) male offspring exhibiting ASD-like traits, while female offspring displayed attention deficit and hyperactivity disorder (ADHD)-like traits; (viii) IL-1 and/or NF-kB blockade alleviate placental and fetal inflammation, as well as subsequent neurobehavioral impairments. These findings offer potential therapeutic avenues, including sex-adapted anti-inflammatory treatment (e.g., blocking IL-1; repurposing of FDA-approved IL-1 receptor antagonist (IL-1Ra) treatment). Blocking the IL-1 pathway offers therapeutic potential to alleviate chorioamnionitis-related disabilities, presenting an opportunity for a human phase II RCT that uses IL-1 blockade added to the classic antibiotic treatment of chorioamnionitis.
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Affiliation(s)
- Seline Vancolen
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada;
- Department of Pediatrics, Research Institute of the McGill University Health Center, Montreal, QC H3G 1Y6, Canada
| | - Taghreed Ayash
- Department of Pediatrics, Research Institute of the McGill University Health Center, Montreal, QC H3G 1Y6, Canada
| | - Marie-Julie Allard
- Department of Pediatrics, Research Institute of the McGill University Health Center, Montreal, QC H3G 1Y6, Canada
| | - Guillaume Sébire
- Department of Pediatrics, Research Institute of the McGill University Health Center, Montreal, QC H3G 1Y6, Canada
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6
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Domínguez K, Lindon AK, Gibbons J, Darch SE, Randis TM. Group B Streptococcus Drives Major Transcriptomic Changes in the Colonic Epithelium. Infect Immun 2023; 91:e0003523. [PMID: 37278645 PMCID: PMC10353456 DOI: 10.1128/iai.00035-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/05/2023] [Indexed: 06/07/2023] Open
Abstract
Group B Streptococcus (GBS) is a leading cause of infant sepsis worldwide. Colonization of the gastrointestinal tract is a critical precursor to late-onset disease in exposed newborns. Neonatal susceptibility to GBS intestinal translocation stems from intestinal immaturity; however, the mechanisms by which GBS exploits the immature host remain unclear. β-hemolysin/cytolysin (βH/C) is a highly conserved toxin produced by GBS capable of disrupting epithelial barriers. However, its role in the pathogenesis of late-onset GBS disease is unknown. Our aim was to determine the contribution of βH/C to intestinal colonization and translocation to extraintestinal tissues. Using our established mouse model of late-onset GBS disease, we exposed animals to GBS COH-1 (WT), a βH/C-deficient mutant (KO), or vehicle control (phosphate-buffered saline [PBS]) via gavage. Blood, spleen, brain, and intestines were harvested 4 days post-exposure for determination of bacterial burden and isolation of intestinal epithelial cells. RNA sequencing was used to examine the transcriptomes of host cells followed by gene ontology enrichment and KEGG pathway analysis. A separate cohort of animals was followed longitudinally to compare colonization kinetics and mortality between WT and KO groups. We demonstrate that dissemination to extraintestinal tissues occurred only in the WT exposed animals. We observed major transcriptomic changes in the colons of colonized animals, but not in the small intestines. We noted differential expression of genes that indicated the role of βH/C in altering epithelial barrier structure and immune response signaling. Overall, our results demonstrate an important role of βH/C in the pathogenesis of late-onset GBS disease.
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Affiliation(s)
- Kristen Domínguez
- Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - April K. Lindon
- Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Justin Gibbons
- Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Sophie E. Darch
- Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Tara M. Randis
- Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
- Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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7
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Gopalakrishna KP, Hillebrand GH, Bhavana VH, Elder JL, D'Mello A, Tettelin H, Hooven TA. Group B Streptococcus Cas9 variants provide insight into programmable gene repression and CRISPR-Cas transcriptional effects. Commun Biol 2023; 6:620. [PMID: 37296208 PMCID: PMC10256743 DOI: 10.1038/s42003-023-04994-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Group B Streptococcus (GBS; S. agalactiae) causes chorioamnionitis, neonatal sepsis, and can also cause disease in healthy or immunocompromised adults. GBS possesses a type II-A CRISPR-Cas9 system, which defends against foreign DNA within the bacterial cell. Several recent publications have shown that GBS Cas9 influences genome-wide transcription through a mechanism uncoupled from its function as a specific, RNA-programmable endonuclease. We examine GBS Cas9 effects on genome-wide transcription through generation of several isogenic variants with specific functional defects. We compare whole-genome RNA-seq from Δcas9 GBS with a full-length Cas9 gene deletion; dcas9 defective in its ability to cleave DNA but still able to bind to frequently occurring protospacer adjacent motifs; and scas9 that retains its catalytic domains but is unable to bind protospacer adjacent motifs. Comparing scas9 GBS to the other variants, we identify nonspecific protospacer adjacent motif binding as a driver of genome-wide, Cas9 transcriptional effects in GBS. We also show that Cas9 transcriptional effects from nonspecific scanning tend to influence genes involved in bacterial defense and nucleotide or carbohydrate transport and metabolism. While genome-wide transcription effects are detectable by analysis of next-generation sequencing, they do not result in virulence changes in a mouse model of sepsis. We also demonstrate that catalytically inactive dCas9 expressed from the GBS chromosome can be used with a straightforward, plasmid-based, single guide RNA expression system to suppress transcription of specific GBS genes without potentially confounding off-target effects. We anticipate that this system will be useful for study of nonessential and essential gene roles in GBS physiology and pathogenesis.
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Affiliation(s)
| | - Gideon H Hillebrand
- University of Pittsburgh School of Medicine, Program in Microbiology and Immunology, Pittsburgh, PA, USA
| | - Venkata H Bhavana
- University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, USA
| | - Jordan L Elder
- The Cleveland Clinic, Clinical Laboratory Services, Cleveland, OH, USA
| | - Adonis D'Mello
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hervé Tettelin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Thomas A Hooven
- University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, USA.
- Richard King Mellon Institute for Pediatric Research, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
- UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.
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8
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Gopalakrishna KP, Hillebrand GH, Bhavana VH, Elder JL, D'Mello A, Tettelin H, Hooven TA. Group B Streptococcus Cas9 variants provide insight into programmable gene repression and CRISPR-Cas transcriptional effects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.24.542094. [PMID: 37292749 PMCID: PMC10245859 DOI: 10.1101/2023.05.24.542094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Group B Streptococcus (GBS; S. agalactiae ) causes chorioamnionitis, neonatal sepsis, and can also cause disease in healthy or immunocompromised adults. GBS possesses a type II-A CRISPR-Cas9 system, which defends against foreign DNA within the bacterial cell. Several recent publications have shown that GBS Cas9 influences genome-wide transcription through a mechanism uncoupled from its function as a specific, RNA-programmable endonuclease. We examine GBS Cas9 effects on genome-wide transcription through generation of several isogenic variants with specific functional defects. We compare whole-genome RNA-seq from Δ cas9 GBS with a full-length Cas9 gene deletion; dcas9 defective in its ability to cleave DNA but still able to bind to frequently occurring protospacer adjacent motifs; and scas9 that retains its catalytic domains but is unable to bind protospacer adjacent motifs. Comparing scas9 GBS to the other variants, we identify nonspecific protospacer adjacent motif binding as a driver of genome-wide, Cas9 transcriptional effects in GBS. We also show that Cas9 transcriptional effects from nonspecific scanning tend to influence genes involved in bacterial defense and nucleotide or carbohydrate transport and metabolism. While genome-wide transcription effects are detectable by analysis of next-generation sequencing, they do not result in virulence changes in a mouse model of sepsis. We also demonstrate that catalytically inactive dCas9 expressed from the GBS chromosome can be used with a straightforward, plasmid-based, single guide RNA expression system to suppress transcription of specific GBS genes without potentially confounding off-target effects. We anticipate that this system will be useful for study of nonessential and essential gene roles in GBS physiology and pathogenesis.
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9
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Kuperwaser F, Avital G, Vaz MJ, Noble KN, Dammann AN, Randis TM, Aronoff DM, Ratner AJ, Yanai I. Host inflammatory dynamics reveal placental immune modulation by Group B Streptococcus during pregnancy. Mol Syst Biol 2023; 19:e11021. [PMID: 36744393 PMCID: PMC9996236 DOI: 10.15252/msb.202211021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 01/06/2023] [Accepted: 01/10/2023] [Indexed: 02/07/2023] Open
Abstract
Group B Streptococcus (GBS) is a pathobiont that can ascend to the placenta and cause adverse pregnancy outcomes, in part through production of the toxin β-hemolysin/cytolysin (β-h/c). Innate immune cells have been implicated in the response to GBS infection, but the impact of β-h/c on their response is poorly defined. We show that GBS modulates innate immune cell states by subversion of host inflammation through β-h/c, allowing worse outcomes. We used an ascending mouse model of GBS infection to measure placental cell state changes over time following infection with a β-h/c-deficient and isogenic wild type GBS strain. Transcriptomic analysis suggests that β-h/c-producing GBS elicit a worse phenotype through suppression of host inflammatory signaling in placental macrophages and neutrophils, and comparison of human placental macrophages infected with the same strains recapitulates these results. Our findings have implications for identification of new targets in GBS disease to support host defense against pathogenic challenge.
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Affiliation(s)
- Felicia Kuperwaser
- Institute for Computational MedicineNYU Grossman School of MedicineNew YorkNYUSA
| | - Gal Avital
- Institute for Computational MedicineNYU Grossman School of MedicineNew YorkNYUSA
| | - Michelle J Vaz
- Department of PediatricsNYU Grossman School of MedicineNew YorkNYUSA
| | - Kristen N Noble
- Division of Neonatology, Department of PediatricsVanderbilt University Medical CenterNashvilleTNUSA
| | - Allison N Dammann
- Renaissance School of Medicine at Stony Brook UniversityStony BrookNYUSA
| | - Tara M Randis
- Departments of Pediatrics and Molecular Medicine, Morsani School of MedicineUniversity of South FloridaFLTampaUSA
| | | | - Adam J Ratner
- Department of PediatricsNYU Grossman School of MedicineNew YorkNYUSA
- Department of MicrobiologyNYU Grossman School of MedicineNew YorkNYUSA
| | - Itai Yanai
- Institute for Computational MedicineNYU Grossman School of MedicineNew YorkNYUSA
- Department of Biochemistry and Molecular PharmacologyNYU Grossman School of MedicineNew YorkNYUSA
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10
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Zhu B, Tao Z, Edupuganti L, Serrano MG, Buck GA. Roles of the Microbiota of the Female Reproductive Tract in Gynecological and Reproductive Health. Microbiol Mol Biol Rev 2022; 86:e0018121. [PMID: 36222685 PMCID: PMC9769908 DOI: 10.1128/mmbr.00181-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The microbiome of the female reproductive tract defies the convention that high biodiversity is a hallmark of an optimal ecosystem. Although not universally true, a homogeneous vaginal microbiome composed of species of Lactobacillus is generally associated with health, whereas vaginal microbiomes consisting of other taxa are generally associated with dysbiosis and a higher risk of disease. The past decade has seen a rapid advancement in our understanding of these unique biosystems. Of particular interest, substantial effort has been devoted to deciphering how members of the microbiome of the female reproductive tract impact pregnancy, with a focus on adverse outcomes, including but not limited to preterm birth. Herein, we review recent research efforts that are revealing the mechanisms by which these microorganisms of the female reproductive tract influence gynecologic and reproductive health of the female reproductive tract.
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Affiliation(s)
- Bin Zhu
- Microbiology & Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
- Center for Microbiome Engineering and Data Analysis, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Zhi Tao
- Microbiology & Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
- Center for Microbiome Engineering and Data Analysis, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Obstetrics and Gynecology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, People’s Republic of China
| | - Laahirie Edupuganti
- Microbiology & Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
- Center for Microbiome Engineering and Data Analysis, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Myrna G. Serrano
- Microbiology & Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
- Center for Microbiome Engineering and Data Analysis, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Gregory A. Buck
- Microbiology & Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
- Center for Microbiome Engineering and Data Analysis, Virginia Commonwealth University, Richmond, Virginia, USA
- Computer Science, School of Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
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11
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Virulence Profiles and Antimicrobial Resistance of Streptococcus agalactiae Infective and Colonizing Strains from Argentina. Curr Microbiol 2022; 79:392. [DOI: 10.1007/s00284-022-03050-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/20/2022] [Indexed: 11/05/2022]
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12
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Avital G, Kuperwaser F, Pountain AW, Lacey KA, Zwack EE, Podkowik M, Shopsin B, Torres VJ, Yanai I. The tempo and mode of gene regulatory programs during bacterial infection. Cell Rep 2022; 41:111477. [PMID: 36223751 PMCID: PMC9741813 DOI: 10.1016/j.celrep.2022.111477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 06/10/2022] [Accepted: 09/20/2022] [Indexed: 12/14/2022] Open
Abstract
Innate immune recognition of bacterial pathogens is a key determinant of the ensuing systemic response, and host or pathogen heterogeneity in this early interaction can impact the course of infection. To gain insight into host response heterogeneity, we investigate macrophage inflammatory dynamics using primary human macrophages infected with Group B Streptococcus. Transcriptomic analysis reveals discrete cellular states within responding macrophages, one of which consists of four sub-states, reflecting inflammatory activation. Infection with six additional bacterial species-Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Yersinia pseudotuberculosis, Shigella flexneri, and Salmonella enterica-recapitulates these states, though at different frequencies. We show that modulating the duration of infection and the presence of a toxin impacts inflammatory trajectory dynamics. We provide evidence for this trajectory in infected macrophages in an in vivo model of Staphylococcus aureus infection. Our cell-state analysis defines a framework for understanding inflammatory activation dynamics in response to bacterial infection.
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Affiliation(s)
- Gal Avital
- Institute for Computational Medicine, NYU Grossman School of Medicine, New York, NY, USA,These authors contributed equally
| | - Felicia Kuperwaser
- Institute for Computational Medicine, NYU Grossman School of Medicine, New York, NY, USA,These authors contributed equally
| | - Andrew W. Pountain
- Institute for Computational Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Keenan A. Lacey
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Erin E. Zwack
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Magdalena Podkowik
- Department of Medicine, Division of Infectious Diseases, NYU Grossman School of Medicine, New York, NY, USA
| | - Bo Shopsin
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA,Department of Medicine, Division of Infectious Diseases, NYU Grossman School of Medicine, New York, NY, USA
| | - Victor J. Torres
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Itai Yanai
- Institute for Computational Medicine, NYU Grossman School of Medicine, New York, NY, USA,Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY, USA,Lead contact,Correspondence:
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13
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Keith MF, Gopalakrishna KP, Bhavana VH, Hillebrand GH, Elder JL, Megli CJ, Sadovsky Y, Hooven TA. Nitric Oxide Production and Effects in Group B Streptococcus Chorioamnionitis. Pathogens 2022; 11:1115. [PMID: 36297171 PMCID: PMC9608865 DOI: 10.3390/pathogens11101115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Intrauterine infection, or chorioamnionitis, due to group B Streptococcus (GBS) is a common cause of miscarriage and preterm birth. To cause chorioamnionitis, GBS must bypass maternal-fetal innate immune defenses including nitric oxide (NO), a microbicidal gas produced by nitric oxide synthases (NOS). This study examined placental NO production and its role in host-pathogen interactions in GBS chorioamnionitis. In a murine model of ascending GBS chorioamnionitis, placental NOS isoform expression quantified by RT-qPCR revealed a four-fold expression increase in inducible NOS, no significant change in expression of endothelial NOS, and decreased expression of neuronal NOS. These NOS expression results were recapitulated ex vivo in freshly collected human placental samples that were co-incubated with GBS. Immunohistochemistry of wild type C57BL/6 murine placentas with GBS chorioamnionitis demonstrated diffuse inducible NOS expression with high-expression foci in the junctional zone and areas of abscess. Pregnancy outcomes between wild type and inducible NOS-deficient mice did not differ significantly although wild type dams had a trend toward more frequent preterm delivery. We also identified possible molecular mechanisms that GBS uses to survive in a NO-rich environment. In vitro exposure of GBS to NO resulted in dose-dependent growth inhibition that varied by serovar. RNA-seq on two GBS strains with distinct NO resistance phenotypes revealed that both GBS strains shared several detoxification pathways that were differentially expressed during NO exposure. These results demonstrate that the placental immune response to GBS chorioamnionitis includes induced NO production and indicate that GBS activates conserved stress pathways in response to NO exposure.
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Affiliation(s)
- Mary Frances Keith
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | | | | | - Gideon Hayden Hillebrand
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Jordan Lynn Elder
- Manual Hematology and Coagulation Department, The Cleveland Clinic, Cleveland, OH 44195, USA
| | - Christina Joann Megli
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- UPMC Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Yoel Sadovsky
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- UPMC Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Thomas Alexander Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
- UPMC Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
- UPMC Children’s Hospital of Pittsburgh Richard King Mellon Institute for Pediatric Research, Pittsburgh, PA 15224, USA
- UPMC Children’s Hospital of Pittsburgh, 4401 Penn Ave. Rangos Research Building #8128, Pittsburgh, PA 15224, USA
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14
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Korir ML, Doster RS, Lu J, Guevara MA, Spicer SK, Moore RE, Francis JD, Rogers LM, Haley KP, Blackman A, Noble KN, Eastman AJ, Williams JA, Damo SM, Boyd KL, Townsend SD, Henrique Serezani C, Aronoff DM, Manning SD, Gaddy JA. Streptococcus agalactiae cadD alleviates metal stress and promotes intracellular survival in macrophages and ascending infection during pregnancy. Nat Commun 2022; 13:5392. [PMID: 36104331 PMCID: PMC9474517 DOI: 10.1038/s41467-022-32916-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/24/2022] [Indexed: 01/17/2023] Open
Abstract
Perinatal infection with Streptococcus agalactiae, or Group B Streptococcus (GBS), is associated with preterm birth, neonatal sepsis, and stillbirth. Here, we study the interactions of GBS with macrophages, essential sentinel immune cells that defend the gravid reproductive tract. Transcriptional analyses of GBS-macrophage co-cultures reveal enhanced expression of a gene encoding a putative metal resistance determinant, cadD. Deletion of cadD reduces GBS survival in macrophages, metal efflux, and resistance to metal toxicity. In a mouse model of ascending infection during pregnancy, the ΔcadD strain displays attenuated bacterial burden, inflammation, and cytokine production in gestational tissues. Furthermore, depletion of host macrophages alters cytokine expression and decreases GBS invasion in a cadD-dependent fashion. Our results indicate that GBS cadD plays an important role in metal detoxification, which promotes immune evasion and bacterial proliferation in the pregnant host.
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Affiliation(s)
- Michelle L Korir
- Michigan State University, Department of Microbiology and Molecular Genetics, East Lansing, MI, USA
- Aurora University, Department of Biology, Aurora, IL, USA
| | - Ryan S Doster
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Stanford University, Palo Alto, CA, USA
| | - Miriam A Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sabrina K Spicer
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Rebecca E Moore
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Jamisha D Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lisa M Rogers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kathryn P Haley
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Biomedical Sciences, Grand Valley State University, Allendale, MI, USA
| | - Amondrea Blackman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kristen N Noble
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alison J Eastman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Janice A Williams
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
| | - Steven M Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, USA
- Department of Biochemistry and Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Kelli L Boyd
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - C Henrique Serezani
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - David M Aronoff
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shannon D Manning
- Michigan State University, Department of Microbiology and Molecular Genetics, East Lansing, MI, USA.
| | - Jennifer A Gaddy
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
- Center for Medicine, Health, and Society, Vanderbilt University, Nashville, TN, USA.
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, TN, USA.
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15
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Rosa-Fraile M, Alós JI. Group B Streptococcus neonatal infections, the ongoing history. ENFERMEDADES INFECCIOSAS Y MICROBIOLOGIA CLINICA (ENGLISH ED.) 2022; 40:349-352. [PMID: 35906029 DOI: 10.1016/j.eimce.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 01/12/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Manuel Rosa-Fraile
- Emeritus, Servicio de Microbiología, Hospital Universitario Virgen de las Nieves, Granada, Spain.
| | - Juan-Ignacio Alós
- Servicio de Microbiología, Hospital Universitario de Getafe, Getafe, Madrid, Spain
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16
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Kurian NK, Modi D. Mechanisms of group B Streptococcus-mediated preterm birth: lessons learnt from animal models. REPRODUCTION AND FERTILITY 2022; 3:R109-R120. [PMID: 35794927 PMCID: PMC9254271 DOI: 10.1530/raf-21-0105] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 06/07/2022] [Indexed: 11/22/2022] Open
Abstract
Group B Streptococcus (GBS) is an opportunistic pathogenic bacterium which upon colonization in the female reproductive tract can cause preterm births, fetal injury, and demise. Several determinants for GBS pathogenesis have been explored so far through the studies using animal models ranging from mice to non-human primates. The results from these experimental data have identified outer membrane vesicles, β-hemolysin, hyaluronidase, and Cas9 of GBS as major virulence factors leading to preterm births. Most of these factors drive inflammation through activation of NLRP3 and elevated production of IL1-β. However, the absence of one of the factors from the pathogen reduces but does not completely abolish the pathogenesis of GBS suggesting the involvement of more than one factor in causing preterm birth. This makes further exploration of other virulence factors of GBS pathogenesis important in gaining an insight into the mechanistic basis of GBS-mediated preterm births. Lay summary Group B Streptococcus (GBS) is a pathogenic bacteria whose infection in the reproductive tract during pregnancy can cause premature delivery. This bacterial infection is one of the major causes of death of mother and baby during pregnancy, and the bacteria is prevalent in all parts of the world. This makes the research on GBS so important and many of the mechanisms behind GBS infection during pregnancy still remain unexplored. In this review, we have outlined how various animal models contributed in finding the mechanism of GBS pathogenesis. The review also focuses on compiling various virulence factors which makes GBS pathogenic in the vulnerable. Understanding the mechanisms of infection by GBS will be crucial in developing drugs and vaccines to protect against the harmful effects of the bacteria.
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Affiliation(s)
- Noble K Kurian
- Department of Microbiology, Atmiya University, Rajkot, Gujarat, India
| | - Deepak Modi
- Molecular and Cellular Biology Laboratory, ICMR-National Institute for Research in Reproductive Health and Child Health (NIRRCH), Indian Council of Medical Research (ICMR), Mumbai, India
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17
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Bekele H, Debella A, Getachew T, Balis B, Tamiru D, Eyeberu A, Tiruye G, Kure MA, Habte S, Eshetu B, Regassa LD, Mesfin S, Alemu A, Dessie Y, Shiferaw K. Prevalence of Group B Streptococcus Recto-Vaginal Colonization, Vertical Transmission, and Antibiotic Susceptibility Among Pregnant Women in Ethiopia: A Systematic Review and Meta-Analysis. Front Public Health 2022; 10:851434. [PMID: 35651858 PMCID: PMC9149289 DOI: 10.3389/fpubh.2022.851434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
Background Maternal Group B Streptococcus (GBS) recto-vaginal colonization is the most common route for early onset neonatal GBS diseases. A good understanding of the rate of maternal GBS colonization, vertical transmission rate, and antibiotic susceptibility profiles is needed to formulate a broad protection mechanism, like vaccine preparation. For that reason, this meta-analysis aimed at determining the pooled prevalence of GBS recto-vaginal colonization, vertical transmission rate, and antibiotic susceptibility profiles in Ethiopia. Methods Both published and unpublished studies were searched from MEDLINE/PubMed, CINAHL (EBSCO), Embase, Cochrane Library, SCOPUS, Web of Sciences databases, and Google Scholar. Independent selection was then carried out by the authors based on the eligibility criteria and data extraction using Microsoft excel. The authors then used STATA version 14.1 software for further cleaning and analysis. The review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses) PRISMA guidelines. Using the random-effect model, the prevalence with a 95% confidence interval (CI) and forest plot were used to present the findings. Besides, the studies' heterogeneity was assessed using Cochrane chi-square (I2) statistics, while Egger intercept was used to assess publication bias. Results This review included nineteen studies. The pooled prevalence of recto-vaginal colonization was 15% (95% CI: 11, 19), while the prevalence of vertical transmission was 51% (95% CI: 45, 58) and highest-level susceptibility to vancomycin was 99% (95% CI: 98, 100). However, the GBS susceptibility to tetracycline was 23% (95% CI: 9, 36). Conclusions Nearly one out of seven pregnant women in Ethiopia had recto-vaginal colonization of GBS. As a result, half of the pregnancies end with vertical transmission of GBS. Hence, the review emphasizes that policy and programs should consider planning and implementing prophylactic programs. Systematic Review Registration https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021287540.
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Affiliation(s)
- Habtamu Bekele
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Adera Debella
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Tamirat Getachew
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Bikila Balis
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Dawit Tamiru
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Addis Eyeberu
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Getahun Tiruye
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Mohammed Abdurke Kure
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Sisay Habte
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Bajrond Eshetu
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Lemma Demissie Regassa
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Sinetibeb Mesfin
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Adisu Alemu
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Yadeta Dessie
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Kasiye Shiferaw
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
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18
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Animal Models of Chorioamnionitis: Considerations for Translational Medicine. Biomedicines 2022; 10:biomedicines10040811. [PMID: 35453561 PMCID: PMC9032938 DOI: 10.3390/biomedicines10040811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 02/04/2023] Open
Abstract
Preterm birth is defined as any birth occurring before 37 completed weeks of gestation by the World Health Organization. Preterm birth is responsible for perinatal mortality and long-term neurological morbidity. Acute chorioamnionitis is observed in 70% of premature labor and is associated with a heavy burden of multiorgan morbidities in the offspring. Unfortunately, chorioamnionitis is still missing effective biomarkers and early placento- as well as feto-protective and curative treatments. This review summarizes recent advances in the understanding of the underlying mechanisms of chorioamnionitis and subsequent impacts on the pregnancy outcome, both during and beyond gestation. This review also describes relevant and current animal models of chorioamnionitis used to decipher associated mechanisms and develop much needed therapies. Improved knowledge of the pathophysiological mechanisms underpinning chorioamnionitis based on preclinical models is a mandatory step to identify early in utero diagnostic biomarkers and design novel anti-inflammatory interventions to improve both maternal and fetal outcomes.
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19
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Shahi I, Llaneras CN, Perelman SS, Torres VJ, Ratner AJ. Genome-Wide CRISPR-Cas9 Screen Does Not Identify Host Factors Modulating Streptococcus agalactiae β-Hemolysin/Cytolysin-Induced Cell Death. Microbiol Spectr 2022; 10:e0218621. [PMID: 35196804 PMCID: PMC8865549 DOI: 10.1128/spectrum.02186-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/07/2022] [Indexed: 11/20/2022] Open
Abstract
Pore-forming toxins (PFTs) are commonly produced by pathogenic bacteria, and understanding them is key to the development of virulence-targeted therapies. Streptococcus agalactiae, or group B Streptococcus (GBS), produces several factors that enhance its pathogenicity, including the PFT β-hemolysin/cytolysin (βhc). Little is understood about the cellular factors involved in βhc pore formation. We conducted a whole-genome CRISPR-Cas9 forward genetic screen to identify host genes that might contribute to βhc pore formation and cell death. While the screen identified the established receptor, CD59, in control experiments using the toxin intermedilysin (ILY), no clear candidate genes were identified that were required for βhc-mediated lethality. Of the top targets from the screen, two genes involved in membrane remodeling and repair represented candidates that might modulate the kinetics of βhc-induced cell death. Upon attempted validation of the results using monoclonal cell lines with targeted disruption of these genes, no effect on βhc-mediated cell lysis was observed. The CRISPR-Cas9 screen results are consistent with the hypothesis that βhc does not require a single nonessential host factor to mediate target cell death. IMPORTANCE CRISPR-Cas9 forward genetic screens have been used to identify host cell targets required by bacterial toxins. They have been used successfully to both verify known targets and elucidate novel host factors required by toxins. Here, we show that this approach fails to identify host factors required for cell death due to βhc, a toxin required for GBS virulence. These data suggest that βhc may not require a host cell receptor for toxin function or may require a host receptor that is an essential gene and would not be identified using this screening strategy.
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Affiliation(s)
- Ifrah Shahi
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Cristina N. Llaneras
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sofya S. Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
| | - Adam J. Ratner
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
- Department of Pediatrics, New York University Grossman School of Medicine, New York, New York, USA
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20
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Rosa-Fraile M, Alós JI. Group B Streptococcus neonatal infections, the ongoing history. Enferm Infecc Microbiol Clin 2022. [DOI: 10.1016/j.eimc.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Shang H, Yu J, Li S, Li S. Multi-Drug Resistant Pathogenic Bacteria Caused Intrauterine Infection in Albino Rat Mediated Preterm Labour. INT J PHARMACOL 2022. [DOI: 10.3923/ijp.2022.307.314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Human Milk Oligosaccharides Reduce Murine Group B Streptococcus Vaginal Colonization with Minimal Impact on the Vaginal Microbiota. mSphere 2022; 7:e0088521. [PMID: 34986315 PMCID: PMC8730812 DOI: 10.1128/msphere.00885-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Group B Streptococcus (GBS) colonizes the vaginal mucosa of a significant percentage of healthy women and is a leading cause of neonatal bacterial infections. Currently, pregnant women are screened in the last month of pregnancy, and GBS-positive women are given antibiotics during parturition to prevent bacterial transmission to the neonate. Recently, human milk oligosaccharides (HMOs) isolated from breastmilk were found to inhibit GBS growth and biofilm formation in vitro, and women that make certain HMOs are less likely to be vaginally colonized with GBS. Using in vitro human vaginal epithelial cells and a murine vaginal colonization model, we tested the impact of HMO treatment on GBS burdens and the composition of the endogenous microbiota by 16S rRNA amplicon sequencing. HMO treatment reduced GBS vaginal burdens in vivo with minimal alterations to the vaginal microbiota. HMOs displayed potent inhibitory activity against GBS in vitro, but HMO pretreatment did not alter adherence of GBS or the probiotic Lactobacillus rhamnosus to human vaginal epithelial cells. In addition, disruption of a putative GBS glycosyltransferase (Δsan_0913) rendered the bacterium largely resistant to HMO inhibition in vitro and in vivo but did not compromise its adherence, colonization, or biofilm formation in the absence of HMOs. We conclude that HMOs are a promising therapeutic bioactive to limit GBS vaginal colonization with minimal impacts on the vaginal microenvironment. IMPORTANCE During pregnancy, GBS ascension into the uterus can cause fetal infection or preterm birth. In addition, GBS exposure during labor creates a risk of serious disease in the vulnerable newborn and mother postpartum. Current recommended prophylaxis consists of administering broad-spectrum antibiotics to GBS-positive mothers during labor. Although antibiotics have significantly reduced GBS neonatal disease, there are several unintended consequences, including altered neonatal gut bacteria and increased risk for other types of infection. Innovative preventions displaying more targeted antimicrobial activity, while leaving the maternal microbiota intact, are thus appealing. Using a mouse model, we found that human milk oligosaccharides (HMOs) reduce GBS burdens without perturbing the vaginal microbiota. We conclude that HMOs are a promising alternative to antibiotics to reduce GBS neonatal disease.
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23
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Abstract
Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.
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24
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Group B Streptococcus CAMP Factor Does Not Contribute to Interactions with the Vaginal Epithelium and Is Dispensable for Vaginal Colonization in Mice. Microbiol Spectr 2021; 9:e0105821. [PMID: 34908468 PMCID: PMC8672899 DOI: 10.1128/spectrum.01058-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Gram-positive pathogen group B Streptococcus (GBS) is a leading cause of neonatal bacterial infections, preterm birth, and stillbirth. Although maternal GBS vaginal colonization is a risk factor for GBS-associated adverse birth outcomes, mechanisms promoting GBS vaginal persistence are not fully defined. GBS possesses a broadly conserved small molecule, CAMP factor, that is co-hemolytic in the presence of Staphylococcus aureus sphingomyelinase C. While this co-hemolytic reaction is commonly used by clinical laboratories to identify GBS, the contribution of CAMP factor to GBS vaginal persistence is unknown. Using in vitro biofilm, adherence and invasion assays with immortalized human vaginal epithelial VK2 cells, and a mouse model of GBS vaginal colonization, we tested the contribution of CAMP factor using GBS strain COH1 and its isogenic CAMP-deficient mutant (Δcfb). We found no evidence for CAMP factor involvement in GBS biofilm formation, or adherence, invasion, or cytotoxicity toward VK2 cells in the presence or absence of S. aureus. Additionally, there was no difference in vaginal burdens or persistence between COH1 and Δcfb strains in a murine colonization model. In summary, our results using in vitro human cell lines and murine models do not support a critical role for CAMP factor in promoting GBS vaginal colonization. IMPORTANCE Group B Streptococcus (GBS) remains a pervasive pathogen for pregnant women and their newborns. Maternal screening and intrapartum antibiotic prophylaxis to GBS-positive mothers have reduced, but not eliminated GBS neonatal disease, and have not impacted GBS-associated preterm birth or stillbirth. Additionally, this antibiotic exposure is associated with adverse effects on the maternal and neonatal microbiota. Identifying key GBS factors important for maternal vaginal colonization will foster development of more targeted, alternative therapies to antibiotic treatment. Here, we investigate the contribution of a broadly conserved GBS determinant, CAMP factor, to GBS vaginal colonization and find that CAMP factor is unlikely to be a biological target to control maternal GBS colonization.
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Dammann AN, Chamby AB, Gonzalez FJ, Sharp ME, Flores K, Shahi I, Dongas S, Hooven TA, Ratner AJ. Group B Streptococcus capsular serotype alters vaginal colonization fitness. J Infect Dis 2021; 225:1896-1904. [PMID: 34788438 DOI: 10.1093/infdis/jiab559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 11/02/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) remains a leading cause of infant morbidity and mortality. A candidate vaccine targets six GBS serotypes, offering a potential alternative to intrapartum antibiotic prophylaxis to reduce disease burden. However, our understanding of the contributions of specific capsule types to GBS colonization and disease remains limited. METHODS Using allelic exchange, we generated isogenic GBS strains differing only in the serotype-determining region in two genetic backgrounds, including the hypervirulent clonal complex (CC) 17. Using a murine model of vaginal co-colonization, we evaluated the roles of the presence of capsule and of expression of specific capsular types in GBS vaginal colonization fitness independent of other genetic factors. RESULTS Encapsulated wild-type strains COH1 (CC17, serotype III) and A909 (non-CC17, serotype Ia), outcompeted isogenic acapsular mutants in murine vaginal co-colonization. COH1 wild-type outcompeted A909. Notably, expression of type Ia capsule conferred an advantage over type III capsule in both genetic backgrounds. CONCLUSIONS Specific capsule types may provide an advantage in GBS vaginal colonization in vivo. However, success of certain GBS lineages, including CC17, likely involves both capsule and non-capsule genetic elements. Capsule switching in GBS, a potential outcome of conjugate vaccine programs, may alter colonization fitness or pathogenesis.
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Affiliation(s)
- Allison N Dammann
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Anna B Chamby
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Francisco J Gonzalez
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Molly E Sharp
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Karina Flores
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ifrah Shahi
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Sophia Dongas
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Thomas A Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Richard King Mellon Institute for Pediatric Research, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Adam J Ratner
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA.,Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
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Noble K, Lu J, Guevara MA, Doster RS, Chambers SA, Rogers LM, Moore RE, Spicer SK, Eastman AJ, Francis JD, Manning SD, Rajagopal L, Aronoff DM, Townsend SD, Gaddy JA. Group B Streptococcus cpsE Is Required for Serotype V Capsule Production and Aids in Biofilm Formation and Ascending Infection of the Reproductive Tract during Pregnancy. ACS Infect Dis 2021; 7:2686-2696. [PMID: 34076405 DOI: 10.1021/acsinfecdis.1c00182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Group B Streptococcus (GBS) is an encapsulated Gram-positive pathogen that causes ascending infections of the reproductive tract during pregnancy. The capsule of this organism is a critical virulence factor that has been implicated in a variety of cellular processes to promote pathogenesis. Primarily comprised of carbohydrates, the GBS capsule and its synthesis is driven by the capsule polysaccharide synthesis (cps) operon. The cpsE gene within this operon encodes a putative glycosyltransferase that is responsible for the transfer of a Glc-1-P from UDP-Glc to an undecaprenyl lipid molecule. We hypothesized that the cpsE gene product is important for GBS virulence and ascending infection during pregnancy. Our work demonstrates that a GBS cpsE mutant secretes fewer carbohydrates, has a reduced capsule, and forms less biofilm than the wild-type parental strain. We show that, compared to the parental strain, the ΔcpsE deletion mutant is more readily taken up by human placental macrophages and has a significantly attenuated ability to invade and proliferate in the mouse reproductive tract. Taken together, these results demonstrate that the cpsE gene product is an important virulence factor that aids in GBS colonization and invasion of the gravid reproductive tract.
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Affiliation(s)
- Kristen Noble
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Miriam A. Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Ryan S. Doster
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Schuyler A. Chambers
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Lisa M. Rogers
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Rebecca E. Moore
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Sabrina K. Spicer
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Alison J. Eastman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Jamisha D. Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48823, United States
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington, Seattle, Washington 98109, United States
| | - David M. Aronoff
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
- Departments of Biochemistry and Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Steven D. Townsend
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Jennifer A. Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee 37212, United States
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Functional Insights into the High-Molecular-Mass Penicillin-Binding Proteins of Streptococcus agalactiae Revealed by Gene Deletion and Transposon Mutagenesis Analysis. J Bacteriol 2021; 203:e0023421. [PMID: 34124943 DOI: 10.1128/jb.00234-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
High-molecular-mass penicillin-binding proteins (PBPs) are enzymes that catalyze the biosynthesis of bacterial cell wall peptidoglycan. The Gram-positive bacterial pathogen Streptococcus agalactiae (group B streptococcus [GBS]) produces five high-molecular-mass PBPs, namely, PBP1A, PBP1B, PBP2A, PBP2B, and PBP2X. Among these, only PBP2X is essential for cell viability, whereas the other four PBPs are individually dispensable. The biological function of the four nonessential PBPs is poorly characterized in GBS. We deleted the pbp1a, pbp1b, pbp2a, and pbp2b genes individually from a genetically well-characterized serotype V GBS strain and studied the phenotypes of the four isogenic mutant strains. Compared to the wild-type parental strain, (i) none of the pbp isogenic mutant strains had a significant growth defect in Todd-Hewitt broth supplemented with 0.2% yeast extract (THY) rich medium, (ii) isogenic mutant Δpbp1a and Δpbp1b strains had significantly increased susceptibility to penicillin and ampicillin, and (iii) isogenic mutant Δpbp1a and Δpbp2b strains had significantly longer chain lengths. Using saturated transposon mutagenesis and transposon insertion site sequencing, we determined the genes essential for the viability of the wild-type GBS strain and each of the four isogenic pbp deletion mutant strains in THY rich medium. The pbp1a gene is essential for cell viability in the pbp2b deletion background. Reciprocally, pbp2b is essential in the pbp1a deletion background. Moreover, the gene encoding RodA, a peptidoglycan polymerase that works in conjunction with PBP2B, is also essential in the pbp1a deletion background. Together, our results suggest functional overlap between PBP1A and the PBP2B-RodA complex in GBS cell wall peptidoglycan biosynthesis. IMPORTANCE High-molecular-mass penicillin-binding proteins (HMM PBPs) are enzymes required for bacterial cell wall biosynthesis. Bacterial pathogen group B streptococcus (GBS) produces five distinct HMM PBPs. The biological functions of these proteins are not well characterized in GBS. In this study, we performed a comprehensive deletion analysis of genes encoding HMM PBPs in GBS. We found that deleting certain PBP-encoding genes altered bacterial susceptibility to beta-lactam antibiotics, cell morphology, and the essentiality of other enzymes involved in cell wall peptidoglycan synthesis. The results of our study shed new light on the biological functions of PBPs in GBS.
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Brosius Lutz A, Al-Nasiry S, Kramer BW, Mueller M. Understanding Host-Pathogen Interactions in Acute Chorioamnionitis Through the Use of Animal Models. Front Cell Infect Microbiol 2021; 11:709309. [PMID: 34386434 PMCID: PMC8353249 DOI: 10.3389/fcimb.2021.709309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/12/2021] [Indexed: 01/04/2023] Open
Abstract
Inflammation of the chorion and/or amnion during pregnancy is called chorioamnionitis. Acute chorioamnionitis is implicated in approximately 40% of preterm births and has wide-ranging implications for the mother, fetus, and newborn. Large disease burden and lack of therapeutic approaches drive the discovery programs to define and test targets to tackle chorioamnionitis. Central to the advancement of these studies is the use of animal models. These models are necessary to deepen our understanding of basic mechanisms of host-pathogen interactions central to chorioamnionitis disease pathogenesis. Models of chorioamnionitis have been developed in numerous species, including mice, rabbits, sheep, and non-human primates. The various models present an array of strategies for initiating an inflammatory response and unique opportunities for studying its downstream consequences for mother, fetus, or newborn. In this review, we present a discussion of the key features of human chorioamnionitis followed by evaluation of currently available animal models in light of these features and consideration of how these models can be best applied to tackle outstanding questions in the field.
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Affiliation(s)
- Amanda Brosius Lutz
- Department of Obstetrics and Gynecology, Inselspital, Bern University Hospital, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Salwan Al-Nasiry
- Department of Obstetrics and Gynecology, GROW School of Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC), Maastricht, Netherlands
| | - Boris W Kramer
- Department of Pediatrics, Maastricht University Medical Centre (MUMC), Maastricht, Netherlands
| | - Martin Mueller
- Department of Obstetrics and Gynecology, Inselspital, Bern University Hospital, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Department of Pediatrics, Maastricht University Medical Centre (MUMC), Maastricht, Netherlands
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29
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Karaer A, Doğan B, Günal S, Tuncay G, Arda Düz S, Ünver T, Tecellioğlu N. The vaginal microbiota composition of women undergoing assisted reproduction: a prospective cohort study. BJOG 2021; 128:2101-2109. [PMID: 34053157 DOI: 10.1111/1471-0528.16782] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the impact of vaginal microbiota on pregnancy outcomes in women undergoing assisted reproduction. DESIGN A prospective cohort study. SETTING A university-based assisted reproductive technology (ART) centre. POPULATION 223 women undergoing ART treatment. METHODS Prior to embryo transfer, vaginal samples were collected from the posterior fornix. Vaginal microbiota identification was carried out using next-generation sequencing and categorised according to the V3-V4 hypervariable region in the 16S rRNA gene region. MAIN OUTCOME MEASURES ART clinical outcomes (implantation, clinical pregnancy rates and live birth rates). RESULTS The live birth rate in women with community state type (CST)-I (39%) was higher than that in women with CST-III (21.5%) but the difference was not statistically significant (P = 0.052). The relative abundance of Lactobacillus was lower in women who failed to become pregnant (NP group) (67.71%) than in women who became pregnant (PR group) (79.72%). However, this difference was not statistically significant (P = 0.06). In the NP group, the relative abundance of Streptococcus (7.81%) and Gardnerella (9.40%) was higher than that in the PR group (relative abundance of Streptococcus and Gardnerella was 2.28% and 5.56%, respectively). The abundance of Streptococcus was found to be statistically significantly different between the two study groups (P = 0.014). Linear discriminant analysis (LDA) further validated that Streptococcus had the highest contribution (LDA score >4.0) to the difference between these two groups. CONCLUSIONS Streptococcus has the highest contribution to the distinction between the PR and NP groups. TWEETABLE ABSTRACT A relatively high abundance of Streptococcus in the vaginal microbiota may be associated with a lower ART success rate.
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Affiliation(s)
- A Karaer
- Reproductive Science & Advanced Bioinformatics Application & Research Centre, Inonu University, Malatya, Turkey.,Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynaecology, School of Medicine, Inonu University, Malatya, Turkey
| | - B Doğan
- Reproductive Science & Advanced Bioinformatics Application & Research Centre, Inonu University, Malatya, Turkey.,Department of Biomedical Engineering, School of Engineering, Inonu University, Malatya, Turkey
| | - S Günal
- Reproductive Science & Advanced Bioinformatics Application & Research Centre, Inonu University, Malatya, Turkey.,Department of Pharmaceutical Microbiology, School of Pharmacy, Inonu University, Malatya, Turkey
| | - G Tuncay
- Reproductive Science & Advanced Bioinformatics Application & Research Centre, Inonu University, Malatya, Turkey.,Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynaecology, School of Medicine, Inonu University, Malatya, Turkey
| | - S Arda Düz
- Reproductive Science & Advanced Bioinformatics Application & Research Centre, Inonu University, Malatya, Turkey.,Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynaecology, School of Medicine, Inonu University, Malatya, Turkey
| | - T Ünver
- Department of Pharmaceutical Microbiology, School of Pharmacy, Inonu University, Malatya, Turkey
| | - N Tecellioğlu
- Reproductive Science & Advanced Bioinformatics Application & Research Centre, Inonu University, Malatya, Turkey.,Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynaecology, School of Medicine, Inonu University, Malatya, Turkey
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30
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Gilbert NM, Foster LR, Cao B, Yin Y, Mysorekar IU, Lewis AL. Gardnerella vaginalis promotes group B Streptococcus vaginal colonization, enabling ascending uteroplacental infection in pregnant mice. Am J Obstet Gynecol 2021; 224:530.e1-530.e17. [PMID: 33248136 DOI: 10.1016/j.ajog.2020.11.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 01/17/2023]
Abstract
BACKGROUND Group B Streptococcus is a common vaginal bacterium and the leading cause of invasive fetoplacental infections. Group B Streptococcus in the vagina can invade through the cervix to cause ascending uteroplacental infections or can be transmitted to the neonate during vaginal delivery. Some studies have found that women with a "dysbiotic" polymicrobial or Lactobacillus-depleted vaginal microbiota are more likely to harbor group B Streptococcus. Gardnerella vaginalis is often the most abundant bacteria in the vaginas of women with dysbiosis, while being detected at lower levels in most other women, and has been linked with several adverse pregnancy outcomes. Mouse models of group B Streptococcus and Gardnerella vaginalis colonization have been reported but, to the best of our knowledge, the two have not been studied together. The overarching idea driving this study is that certain members of the dysbiotic vaginal microbiota, such as Gardnerella vaginalis, may directly contribute to the increased rate of group B Streptococcus vaginal colonization observed in women with vaginal dysbiosis. OBJECTIVE We used a mouse model to test the hypothesis that vaginal exposure to Gardnerella vaginalis may facilitate colonization and/or invasive infection of the upper reproductive tract by group B Streptococcus during pregnancy. STUDY DESIGN Timed-pregnant mice were generated using an allogeneic mating strategy with BALB/c males and C57Bl/6 females. Dams were vaginally inoculated at gestational day 14 with group B Streptococcus alone (using a 10-fold lower dose than previously reported models) or coinoculated with group B Streptococcus and Gardnerella vaginalis. Bacterial titers were enumerated in vaginal, uterine horn, and placental tissues at gestational day 17. The presence (Fisher exact tests) and levels (Mann-Whitney U tests) of bacterial titers were compared between mono- and coinoculated dams in each compartment. Relative risks were calculated for outcomes that occurred in both groups. Tissue samples were also examined for evidence of pathophysiology. RESULTS Inoculation of pregnant mice with 107 group B Streptococcus alone did not result in vaginal colonization or ascending infection. In contrast, coinoculation of group B Streptococcus with Gardnerella vaginalis in pregnant mice resulted in a 10-fold higher risk of group B Streptococcus vaginal colonization (relative risk, 10.31; 95% confidence interval, 2.710-59.04; P=.0006 [Fisher exact test]). Ascending group B Streptococcus infection of the uterus and placenta occurred in approximately 40% of coinoculated animals, whereas none of those receiving group B Streptococcus alone developed uterine or placental infections. Immunofluorescence microscopy revealed group B Streptococcus in both the maternal and fetal sides of the placenta. Histologic inflammation and increased proinflammatory cytokines were evident in the setting of group B Streptococcus placental infection. Interestingly, placentas from dams exposed to group B Streptococcus and Gardnerella vaginalis, but without recoverable vaginal or placental bacteria, displayed distinct histopathologic features and cytokine signatures. CONCLUSION These data suggest that Gardnerella vaginalis vaginal exposure can promote group B Streptococcus vaginal colonization, resulting in a greater likelihood of invasive perinatal group B Streptococcus infections. These findings suggest that future clinical studies should examine whether the presence of Gardnerella vaginalis is a risk factor for group B Streptococcus vaginal colonization in women. Because Gardnerella vaginalis can also be present in women without bacterial vaginosis, these findings may be relevant both inside and outside of the context of vaginal dysbiosis.
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31
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Hernandez L, Bottini E, Cadona J, Cacciato C, Monteavaro C, Bustamante A, Sanso AM. Multidrug Resistance and Molecular Characterization of Streptococcus agalactiae Isolates From Dairy Cattle With Mastitis. Front Cell Infect Microbiol 2021; 11:647324. [PMID: 33996629 PMCID: PMC8120232 DOI: 10.3389/fcimb.2021.647324] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/09/2021] [Indexed: 11/28/2022] Open
Abstract
Streptococcus agalactiae is a pathogen-associated to bovine mastitis, a health disorder responsible for significant economic losses in the dairy industry. Antimicrobial therapy remains the main strategy for the control of this bacterium in dairy herds and human In order to get insight on molecular characteristics of S. agalactiae strains circulating among Argentinean cattle with mastitis, we received 1500 samples from 56 dairy farms between 2016 and 2019. We recovered 56 S. agalactiae isolates and characterized them in relation to serotypes, virulence genes, and antimicrobial susceptibility. Serotypes III and II were the most prevalent ones (46% and 41%, respectively), followed by Ia (7%). In relation to the 13 virulence genes screened in this study, the genes spb1, hylB, cylE, and PI-2b were present in all the isolates, meanwhile, bca, cpsA, and rib were detected in different frequencies, 36%, 96%, and 59%, respectively. On the other hand, bac, hvgA, lmb, PI-1, PI-2a, and scpB genes could not be detected in any of the isolates. Disk diffusion method against a panel of eight antimicrobial agents showed an important number of strains resistant simultaneously to five antibiotics. We also detected several resistance-encoding genes, tet(M), tet(O), ermB, aphA3, and lnu(B) (9%, 50%, 32%, 32%, and 5%, respectively). The results here presented are the first molecular data on S. agalactiae isolates causing bovine mastitis in Argentina and provide a foundation for the development of diagnostic, prophylactic, and therapeutic methods, including the perspective of a vaccine.
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Affiliation(s)
- Luciana Hernandez
- Laboratorio de Inmunoquímica y Biotecnología, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Enriqueta Bottini
- Laboratorio de Microbiología Clínica y Experimental, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Jimena Cadona
- Laboratorio de Inmunoquímica y Biotecnología, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Claudio Cacciato
- Laboratorio de Microbiología Clínica y Experimental, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Cristina Monteavaro
- Laboratorio de Microbiología Clínica y Experimental, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Ana Bustamante
- Laboratorio de Inmunoquímica y Biotecnología, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Andrea Mariel Sanso
- Laboratorio de Inmunoquímica y Biotecnología, CIVETAN (CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
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Dammann AN, Chamby AB, Catomeris AJ, Davidson KM, Tettelin H, van Pijkeren JP, Gopalakrishna KP, Keith MF, Elder JL, Ratner AJ, Hooven TA. Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits. PLoS Pathog 2021; 17:e1009116. [PMID: 33684178 PMCID: PMC7971860 DOI: 10.1371/journal.ppat.1009116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/18/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability. Group B Streptococcus (GBS) is a species of Gram-positive bacteria that often colonizes the healthy adult intestinal and reproductive tracts without causing serious symptoms. During pregnancy, however, GBS can invade the pregnant uterus, where it can cause infection of the placenta, fetal membranes, and fetus—a condition known as chorioamnionitis. Chorioamnionitis is associated with serious adverse pregnancy outcomes, including stillbirth, preterm labor, and severe infection of the newborn. GBS can survive in human amniotic fluid, which is low in bacterial nutrients and contains immune molecules that limit microbial persistence, and this ability likely contributes to GBS chorioamnionitis. This study is focused on a single GBS gene that encodes a genetic regulator we called MrvR, which we show is important for GBS resistance to human amniotic fluid. Using a series of genetic techniques combined with animal models of GBS colonization and infection, we show that MrvR also plays a key role in allowing GBS to invade the bloodstream and trigger the inflammatory responses that lead to preterm labor and stillbirth. The study concludes with a survey of other GBS genes whose activity is regulated by MrvR, which seems to be an important contributor to GBS virulence.
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Affiliation(s)
- Allison N. Dammann
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
| | - Anna B. Chamby
- University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Andrew J. Catomeris
- Georgetown University School of Medicine, Washington, District of Columbia, United States of America
| | - Kyle M. Davidson
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jan-Peter van Pijkeren
- Department of Food Science, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kathyayini P. Gopalakrishna
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Mary F. Keith
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jordan L. Elder
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Adam J. Ratner
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University, New York, New York, United States of America
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Richard King Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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33
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Vaz MJ, Purrier SA, Bonakdar M, Chamby AB, Ratner AJ, Randis TM. The Impact of Circulating Antibody on Group B Streptococcus Intestinal Colonization and Invasive Disease. Infect Immun 2020; 89:e00348-20. [PMID: 33077619 PMCID: PMC7927928 DOI: 10.1128/iai.00348-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 10/01/2020] [Indexed: 12/17/2022] Open
Abstract
Gastrointestinal (GI) colonization with group B Streptococcus (GBS) is an important precursor to late-onset (LO) disease in infants. The host-pathogen interactions that mediate progression to invasive disease remain unknown due, in part, to a paucity of robust model systems. Passively acquired maternal GBS-specific antibodies protect newborns from early-onset disease, yet their impact on GI colonization and LO disease is unexplored. Using murine models of both perinatal and postnatal GBS acquisition, we assessed the kinetics of GBS GI colonization, progression to invasive disease, and the role of GBS-specific IgG production in exposed offspring and juvenile mice at age 12 and 14 days, respectively. We defined LO disease as >7 days of life in the perinatal model. We studied the impact of maternal immunization using a whole-cell GBS vaccine on the duration of intestinal colonization and progression to invasive disease after postnatal GBS exposure in offspring. Animals exhibit sustained GI colonization following both perinatal and postnatal exposure to GBS, with 21% and 27%, respectively, developing invasive disease. Intestinal colonization with GBS induces an endogenous IgG response within 20 days of exposure. Maternal vaccination with whole-cell GBS induces production of GBS-specific IgG in dams that is vertically transmitted to their offspring but does not decrease the duration of GBS intestinal colonization or reduce LO mortality following postnatal GBS exposure. Both perinatal and postnatal murine models of GBS acquisition closely recapitulate the human disease state, in which GBS colonizes the intestine and causes LO disease. We demonstrate both endogenous production of anti-GBS IgG in juvenile mice and vertical transfer of antibodies to offspring following maternal vaccination. These models serve as a platform to study critical host-pathogen interactions that mediate LO GBS disease.
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Affiliation(s)
- Michelle J Vaz
- Department of Pediatrics, NYU School of Medicine, New York, New York, USA
| | - Sheryl A Purrier
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Maryam Bonakdar
- Pathobiology Graduate Program, Brown University, Providence, Rhode Island, USA
| | - Anna B Chamby
- The University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Adam J Ratner
- Department of Pediatrics, NYU School of Medicine, New York, New York, USA
- Department of Microbiology, NYU School of Medicine, New York, New York, USA
| | - Tara M Randis
- Department of Pediatrics, University of South Florida, Tampa, Florida, USA
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
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Genetic Basis Underlying the Hyperhemolytic Phenotype of Streptococcus agalactiae Strain CNCTC10/84. J Bacteriol 2020; 202:JB.00504-20. [PMID: 32958630 DOI: 10.1128/jb.00504-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 01/30/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) is a major cause of infections in newborns, pregnant women, and immunocompromised patients. GBS strain CNCTC10/84 is a clinical isolate that has high virulence in animal models of infection and has been used extensively to study GBS pathogenesis. Two unusual features of this strain are hyperhemolytic activity and hypo-CAMP factor activity. These two phenotypes are typical of GBS strains that are functionally deficient in the CovR-CovS two-component regulatory system. A previous whole-genome sequencing study found that strain CNCTC10/84 has intact covR and covS regulatory genes. We investigated CovR-CovS regulation in CNCTC10/84 and discovered that a single-nucleotide insertion in a homopolymeric tract in the covR promoter region underlies the strong hemolytic activity and weak CAMP activity of this strain. Using isogenic mutant strains, we demonstrate that this single-nucleotide insertion confers significantly decreased expression of covR and covS and altered expression of CovR-CovS-regulated genes, including that of genes encoding β-hemolysin and CAMP factor. This single-nucleotide insertion also confers significantly increased GBS survival in human whole blood ex vivo IMPORTANCE Group B streptococcus (GBS) is the leading cause of neonatal sepsis, pneumonia, and meningitis. GBS strain CNCTC10/84 is a highly virulent blood isolate that has been used extensively to study GBS pathogenesis for over 20 years. Strain CNCTC10/84 has an unusually strong hemolytic activity, but the genetic basis is unknown. In this study, we discovered that a single-nucleotide insertion in an intergenic homopolymeric tract is responsible for the elevated hemolytic activity of CNCTC10/84.
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Genome-Wide Assessment of Streptococcus agalactiae Genes Required for Survival in Human Whole Blood and Plasma. Infect Immun 2020; 88:IAI.00357-20. [PMID: 32747604 DOI: 10.1128/iai.00357-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/26/2020] [Indexed: 12/17/2022] Open
Abstract
Streptococcus agalactiae (group B streptococcus, or GBS) is a common cause of bacteremia and sepsis in newborns, pregnant women, and immunocompromised patients. The molecular mechanisms used by GBS to survive and proliferate in blood are not well understood. Here, using a highly virulent GBS strain and transposon-directed insertion site sequencing (TraDIS), we performed genome-wide screens to discover novel GBS genes required for bacterial survival in human whole blood and plasma. The screen identified 85 and 41 genes that are required for GBS growth in whole blood and plasma, respectively. A common set of 29 genes was required in both whole blood and plasma. Targeted gene deletion confirmed that (i) genes encoding methionine transporter (metP) and manganese transporter (mtsA) are crucial for GBS survival in whole blood and plasma, (ii) gene W903_1820, encoding a small multidrug export family protein, contributes significantly to GBS survival in whole blood, (iii) the shikimate pathway gene aroA is essential for GBS growth in whole blood and plasma, and (iv) deletion of srr1, encoding a fibrinogen-binding adhesin, increases GBS survival in whole blood. Our findings provide new insight into the GBS-host interactions in human blood.
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36
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Bayar E, Bennett PR, Chan D, Sykes L, MacIntyre DA. The pregnancy microbiome and preterm birth. Semin Immunopathol 2020; 42:487-499. [PMID: 32797272 PMCID: PMC7508933 DOI: 10.1007/s00281-020-00817-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 07/30/2020] [Indexed: 12/14/2022]
Abstract
Preterm birth is a global health concern and continues to contribute to substantial neonatal morbidity and mortality despite advances in obstetric and neonatal care. The underlying aetiology is multi-factorial and remains incompletely understood. In this review, the complex interplay between the vaginal microbiome in pregnancy and its association with preterm birth is discussed in depth. Advances in the study of bacteriology and an improved understanding of the human microbiome have seen an improved awareness of the vaginal microbiota in both health and in disease.
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Affiliation(s)
- Erna Bayar
- Imperial College Parturition Research Group, Institute for Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London, W12 0HS, UK
| | - Phillip R Bennett
- Imperial College Parturition Research Group, Institute for Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London, W12 0HS, UK.
- March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK.
| | - Denise Chan
- Imperial College Parturition Research Group, Institute for Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London, W12 0HS, UK
| | - Lynne Sykes
- Imperial College Parturition Research Group, Institute for Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London, W12 0HS, UK
- March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
| | - David A MacIntyre
- Imperial College Parturition Research Group, Institute for Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London, W12 0HS, UK
- March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
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Cappelletti M, Presicce P, Kallapur SG. Immunobiology of Acute Chorioamnionitis. Front Immunol 2020; 11:649. [PMID: 32373122 PMCID: PMC7177011 DOI: 10.3389/fimmu.2020.00649] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/23/2020] [Indexed: 12/19/2022] Open
Abstract
Acute chorioamnionitis is characterized by neutrophilic infiltration and inflammation at the maternal fetal interface. It is a relatively common complication of pregnancy and can have devastating consequences including preterm labor, maternal infections, fetal infection/inflammation, fetal lung, brain, and gastrointestinal tract injury. In this review, we will discuss current understanding of the pathogenesis, immunobiology, and mechanisms of this condition. Most commonly, acute chorioamnionitis is a result of ascending infection with relatively low-virulence organisms such as the Ureaplasma species. Furthermore, recent vaginal microbiome studies suggest that there is a link between vaginal dysbiosis, vaginal inflammation, and ascending infection. Although less common, microorganisms invading the maternal-fetal interface via hematogenous route (e.g., Zika virus, Cytomegalovirus, and Listeria) can cause placental villitis and severe fetal inflammation and injury. We will provide an overview of the knowledge gleaned from different animal models of acute chorioamnionitis and the role of different immune cells in different maternal-fetal compartments. Lastly, we will discuss how infectious agents can break the maternal tolerance of fetal allograft during pregnancy and highlight the novel future therapeutic approaches.
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Affiliation(s)
- Monica Cappelletti
- Divisions of Neonatology and Developmental Biology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, United States
| | - Pietro Presicce
- Divisions of Neonatology and Developmental Biology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, United States
| | - Suhas G Kallapur
- Divisions of Neonatology and Developmental Biology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, United States
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38
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Lipid analogs reveal features critical for hemolysis and diminish granadaene mediated Group B Streptococcus infection. Nat Commun 2020; 11:1502. [PMID: 32198389 PMCID: PMC7083881 DOI: 10.1038/s41467-020-15282-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 02/27/2020] [Indexed: 12/17/2022] Open
Abstract
Although certain microbial lipids are toxins, the structural features important for cytotoxicity remain unknown. Increased functional understanding is essential for developing therapeutics against toxic microbial lipids. Group B Streptococci (GBS) are bacteria associated with preterm births, stillbirths, and severe infections in neonates and adults. GBS produce a pigmented, cytotoxic lipid, known as granadaene. Despite its importance to all manifestations of GBS disease, studies towards understanding granadaene’s toxic activity are hindered by its instability and insolubility in purified form. Here, we report the synthesis and screening of lipid derivatives inspired by granadaene, which reveal features central to toxin function, namely the polyene chain length. Furthermore, we show that vaccination with a non-toxic synthetic analog confers the production of antibodies that inhibit granadaene-mediated hemolysis ex vivo and diminish GBS infection in vivo. This work provides unique structural and functional insight into granadaene and a strategy to mitigate GBS infection, which will be relevant to other toxic lipids encoded by human pathogens. Granadaene, produced by Group B Streptococcus (GBS), is a long polyene lipid involved in cellular toxicity and hemolytic activity. Here, the authors synthesize and characterize granadaene-like compounds and show that a non-toxic analog diminishes GBS infection in mice when incorporated into a vaccine formulation.
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Giraud A, Allard MJ, Segura M, Roche F, Patural H, Sébire G. Ampicillin Treatment Increases Placental Interleukin-1 Beta Concentration and Polymorphonuclear Infiltration in Group B Streptococcus-Induced Chorioamnionitis: A Preclinical Study. Neonatology 2020; 117:369-373. [PMID: 32375156 DOI: 10.1159/000506906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 03/02/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Antibiotic therapy during preterm labor with intact membranes has been associated with an increased risk of neonatal death. OBJECTIVES Using an established rat model of group B Streptococcus (GBS)-induced chorioamnionitis, we hypothesized that ampicillin treatment increases placental inflammation, as shown in other bacterial infections. METHODS At gestational day 19, 19 Lewis dams were intraperitoneally (i.p.) inoculated by 108 CFU of β-hemolytic serotype Ia GBS (strain #16955 susceptible to ampicillin). Dams were treated i.p. with either 200 mg/kg of ampicillin (n = 9) or 0.9% saline (n = 10) at 48 and 60 h post-GBS inoculation. Cesarean sections were performed 72 h post-GBS inoculation. RESULTS Ampicillin treatment was associated with an increased number of polymorphonuclear cells (PMN) infiltrating the decidua (mean 1,536 vs. 532 PMN/mm2; p < 0.001) and a higher placental concentration of IL-1β (mean 26.4 vs. 7.9 pg/mg; p < 0.01) compared to saline-treated dams. These effects were observed in dams without GBS bacteremia. Conversely, ampicillin treatment was associated with a decreased placental concentration of proinflammatory cytokines in dams with GBS bacteremia. CONCLUSIONS Ampicillin increases placental inflammation in a rat model of GBS-induced chorioamnionitis without bacteremia. This proinflammatory effect of ampicillin could be due to bacterial lysis. Our findings do not query the intrapartum antibiotic prophylaxis against GBS disease. They pave the way for future preclinical studies combining anti-inflammatory treatments and antibiotic therapy for GBS-induced chorioamnionitis.
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Affiliation(s)
- Antoine Giraud
- Child Neurology Division, Department of Pediatrics, McGill University, Montreal, Québec, Canada, .,EA 4607 SNA EPIS, Université de Lyon, Université Jean Monnet, Saint-Étienne, France,
| | - Marie-Julie Allard
- Child Neurology Division, Department of Pediatrics, McGill University, Montreal, Québec, Canada
| | - Mariela Segura
- Department of Infectiology and Microbiology, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Frédéric Roche
- EA 4607 SNA EPIS, Université de Lyon, Université Jean Monnet, Saint-Étienne, France
| | - Hugues Patural
- EA 4607 SNA EPIS, Université de Lyon, Université Jean Monnet, Saint-Étienne, France.,Neonatal Intensive Care Unit, Centre Hospitalier Universitaire de Saint-Étienne, Saint-Étienne, France
| | - Guillaume Sébire
- Child Neurology Division, Department of Pediatrics, McGill University, Montreal, Québec, Canada
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40
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Determinants of Group B streptococcal virulence potential amongst vaginal clinical isolates from pregnant women. PLoS One 2019; 14:e0226699. [PMID: 31851721 PMCID: PMC6919605 DOI: 10.1371/journal.pone.0226699] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/03/2019] [Indexed: 11/19/2022] Open
Abstract
Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a Gram-positive bacterium isolated from the vaginal tract of approximately 25% of women. GBS colonization of the female reproductive tract is of particular concern during pregnancy as the bacteria can invade gestational tissues or be transmitted to the newborn during passage through the birth canal. Infection of the neonate can result in life-threatening pneumonia, sepsis and meningitis. Thus, surveillance of GBS strains and corresponding virulence potential during colonization is warranted. Here we describe a panel of GBS isolates from the vaginal tracts of a cohort of pregnant women in Michigan, USA. We determined that capsular serotypes III and V were the most abundant across the strain panel, with only one isolate belonging to serotype IV. Further, 12.8% of strains belonged to the hyper-virulent serotype III, sequence type 17 (ST-17) and 15.4% expressed the serine rich repeat glycoprotein-encoding gene srr2. Functional assessment of the colonizing isolates revealed that almost all strains exhibited some level of β-hemolytic activity and that ST-17 strains, which express Srr2, exhibited increased bacterial adherence to vaginal epithelium. Finally, analysis of strain antibiotic susceptibility revealed the presence of antibiotic resistance to penicillin (15.4%), clindamycin (30.8%), erythromycin (43.6%), vancomycin (30.8%), and tetracycline (94.9%), which has significant implications for treatment options. Collectively, these data provide important information on vaginal GBS carriage isolate virulence potential and highlight the value of continued surveillance.
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41
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Kobayashi M, Schrag SJ, Alderson MR, Madhi SA, Baker CJ, Sobanjo-Ter Meulen A, Kaslow DC, Smith PG, Moorthy VS, Vekemans J. WHO consultation on group B Streptococcus vaccine development: Report from a meeting held on 27-28 April 2016. Vaccine 2019; 37:7307-7314. [PMID: 28017431 PMCID: PMC6892266 DOI: 10.1016/j.vaccine.2016.12.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 10/17/2016] [Indexed: 11/29/2022]
Abstract
Globally, group B Streptococcus (GBS) remains a leading cause of sepsis and meningitis in infants in the first 90days of life. Intrapartum antibiotic prophylaxis (IAP) for women at increased risk of transmitting GBS to their newborns has been effective in reducing part, but not all, of the GBS disease burden in many high income countries (HICs). In low- and middle-income countries (LMICs), IAP use is low. Immunization of pregnant women with a GBS vaccine represents an alternative strategy to protecting newborns and young infants, through transplacental antibody transfer and potentially by reducing new vaginal colonization. This vaccination strategy was first suggested in the 1970s and several potential GBS vaccines have completed phase I/II clinical trials. During the 2015 WHO Product Development for Vaccines Advisory Committee meeting, GBS was identified as a high priority for the development of a vaccine for maternal immunization because of the major public health burden posed by GBS in LMICs, and the high technical feasibility for successful development. Following this meeting, the first WHO technical consultation on GBS vaccines was held on the 27th and 28th of April 2016, to consider development pathways for such vaccines, focused on their potential role in reducing newborn and young infant deaths and possibly stillbirths in LMICs. Discussion topics included: (1) pathophysiology of disease; (2) current gaps in the knowledge of global disease burden and serotype distribution; (3) vaccine candidates under development; (4) design considerations for phase III trials; and (5) pathways to licensure, policy recommendations and use. Efforts to address gaps identified in each of these areas are needed to establish the public health need for, the development and deployment of, efficacious GBS vaccines. In particular, more work is required to understand the global disease burden of GBS-associated stillbirths, and to develop quality-assured standardized antibody assays to identify correlates of protection.
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Affiliation(s)
- Miwako Kobayashi
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329-4027, USA; Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Stephanie J Schrag
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329-4027, USA
| | - Mark R Alderson
- Center for Vaccine Innovation and Access, PATH, Seattle, WA 98121, USA
| | - Shabir A Madhi
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, and Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Carol J Baker
- Department of Pediatrics, Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - David C Kaslow
- Center for Vaccine Innovation and Access, PATH, Seattle, WA 98121, USA
| | - Peter G Smith
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK
| | - Vasee S Moorthy
- Initiative for Vaccine Research, World Health Organization, CH-1211 Geneva 27, Switzerland
| | - Johan Vekemans
- Initiative for Vaccine Research, World Health Organization, CH-1211 Geneva 27, Switzerland.
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42
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Modulation of Death and Inflammatory Signaling in Decidual Stromal Cells following Exposure to Group B Streptococcus. Infect Immun 2019; 87:IAI.00729-19. [PMID: 31548323 DOI: 10.1128/iai.00729-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 09/18/2019] [Indexed: 02/07/2023] Open
Abstract
Group B Streptococcus (GBS) is an opportunistic bacterial pathogen that contributes to miscarriage, preterm birth, and serious neonatal infections. Studies have indicated that some multilocus sequence types (STs) of GBS are more likely to cause severe disease than others. We hypothesized that the ability of GBS to elicit varying host responses in maternal decidual tissue during pregnancy is an important factor regulating infection and disease severity. To address this hypothesis, we utilized an antibody microarray to compare changes in production and activation of host signaling proteins in decidualized telomerase-immortalized human endometrial stromal cells (dT-HESCs) following infection with GBS strains from septic neonates or colonized mothers. GBS infection increased levels of total and phosphorylated mitogen-activated protein kinase (MAPK) family members such as p38 and JNK and induced nuclear factor kappa B (NF-κB) pathway activation. Infection also altered the regulation of additional proteins that mediate cell death and inflammation in a strain-specific manner, which could be due to the observed variation in attachment to and invasion of the decidual stromal cells and ability to lyse red blood cells. Further analyses confirmed array results and revealed that p38 promotes programmed necrosis in dT-HESCs. Together, the observed signaling changes may contribute to deregulation of critical developmental signaling cascades and inflammatory responses following infection, both of which could trigger GBS-associated pregnancy complications.
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43
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Vornhagen J, Quach P, Santana-Ufret V, Alishetti V, Brokaw A, Armistead B, Qing Tang H, MacDonald JW, Bammler TK, Adams Waldorf KM, Uldbjerg N, Rajagopal L. Human Cervical Mucus Plugs Exhibit Insufficiencies in Antimicrobial Activity Towards Group B Streptococcus. J Infect Dis 2019; 217:1626-1636. [PMID: 29425317 DOI: 10.1093/infdis/jiy076] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 02/05/2018] [Indexed: 01/31/2023] Open
Abstract
Preterm birth is a leading cause of neonatal mortality and lacks an effective therapy. Ascending microbial infections from the lower genital tract lead to infection of the placenta, amniotic fluid, and fetus causing preterm birth or stillbirth. Directly in the path of an ascending infection is the cervical mucus plug (CMP), a dense mucoid structure in the cervical canal with potential antimicrobial properties. In this study, we aimed to define the components of CMP responsible for antimicrobial activity against a common lower genital tract organism associated with preterm birth and stillbirths, namely, group B streptococcus (GBS). Using a quantitative proteomic approach, we identified antimicrobial factors in CMPs that were collected from healthy human pregnancies. However, we noted that the concentration of antimicrobial peptides present in the human CMPs were insufficient to directly kill GBS, and antimicrobial activity, when observed, was due to antibiotics retained in the CMPs. Despite this insufficiency, CMP proteins were able to activate leukocytes in whole blood resulting in increased rates of bacterial killing, suggesting a role for the CMP in enhancing complement-mediated killing or leukocyte activation. This study provides new insight into how the human CMP may limit ascending bacterial infection.
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Affiliation(s)
- Jay Vornhagen
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington.,Department of Global Health, University of Washington, Seattle
| | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington
| | - Verónica Santana-Ufret
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington
| | - Varchita Alishetti
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington
| | - Alyssa Brokaw
- Department of Global Health, University of Washington, Seattle
| | - Blair Armistead
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington.,Department of Pediatrics, University of Washington, Seattle.,Department of Global Health, University of Washington, Seattle
| | - Hai Qing Tang
- Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Denmark
| | - James W MacDonald
- Environmental and Occupational Health Sciences, University of Washington, Seattle
| | - Theo K Bammler
- Environmental and Occupational Health Sciences, University of Washington, Seattle
| | - Kristina M Adams Waldorf
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington.,Department of Obstetrics and Gynecology, University of Washington, Seattle.,Center for Innate Immunity and Immune Disease, University of Washington, Seattle.,Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Niels Uldbjerg
- Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Denmark
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Washington.,Center for Innate Immunity and Immune Disease, University of Washington, Seattle.,Department of Pediatrics, University of Washington, Seattle.,Department of Global Health, University of Washington, Seattle
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A Counterselectable Sucrose Sensitivity Marker Permits Efficient and Flexible Mutagenesis in Streptococcus agalactiae. Appl Environ Microbiol 2019; 85:AEM.03009-18. [PMID: 30658970 DOI: 10.1128/aem.03009-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 01/13/2019] [Indexed: 12/25/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus [GBS]) is a cause of severe infections, particularly during the newborn period. While methods exist for generating chromosomal mutations in GBS, they are cumbersome and inefficient and present significant challenges if the goal is to study subtle mutations, such as single-base-pair polymorphisms. To address this problem, we have developed an efficient and flexible GBS mutagenesis protocol based on sucrose counterselection against levansucrase (SacB) expressed from a temperature-selective shuttle vector. GBS containing the SacB expression cassette demonstrates lethal sensitivity to supplemental sucrose whether the plasmid DNA is replicating outside of the chromosome or has been integrated during a crossover event. Transmission electron microscopy shows that SacB-mediated lethal sucrose sensitivity results from the accumulation of inclusion bodies that eventually lead to complete degradation of normal cellular architecture and subsequent lysis. We used this new mutagenesis technique to generate an in-frame, allelic exchange knockout of the GBS sortase gene srtA, demonstrating that >99% of colonies that emerge from our protocol had the expected knockout phenotype and that among a subset tested by sequencing, 100% had the correct genotype. We also generated barcoded nonsense mutations in the cylE gene in two GBS strains, showing that the approach can be used to make small, precise chromosomal mutations.IMPORTANCE The ability to generate chromosomal mutations is fundamental to microbiology. Historically, however, GBS pathogenesis research has been made challenging by the relative genetic intractability of the organism. Generating a single knockout in GBS using traditional techniques can take many months, with highly variable success rates. Furthermore, traditional methods do not offer a straightforward way to generate single-base-pair polymorphisms or other subtle changes, especially to noncoding regions of the chromosome. We have developed a new sucrose counterselection-based method that permits rapid, efficient, and flexible GBS mutagenesis. Our technique requires no additional equipment beyond what is needed for traditional approaches. We believe that it will catalyze rapid advances in GBS genetics research by significantly easing the path to generating mutants.
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45
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Sutton JA, Rogers LM, Dixon B, Kirk L, Doster R, Algood HM, Gaddy JA, Flaherty R, Manning SD, Aronoff DM. Protein kinase D mediates inflammatory responses of human placental macrophages to Group B Streptococcus. Am J Reprod Immunol 2019; 81:e13075. [PMID: 30582878 PMCID: PMC6459189 DOI: 10.1111/aji.13075] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/11/2018] [Accepted: 12/18/2018] [Indexed: 01/22/2023] Open
Abstract
PROBLEM During pregnancy, Group B Streptococcus (GBS) can infect fetal membranes to cause chorioamnionitis, resulting in adverse pregnancy outcomes. Macrophages are the primary resident phagocyte in extraplacental membranes. Protein kinase D (PKD) was recently implicated in mediating pro-inflammatory macrophage responses to GBS outside of the reproductive system. This work aimed to characterize the human placental macrophage inflammatory response to GBS and address the extent to which PKD mediates such effects. METHOD Primary human placental macrophages were infected with GBS in the presence or absence of a specific, small molecule PKD inhibitor, CRT 0066101. Macrophage phenotypes were characterized by evaluating gene expression, cytokine release, assembly of the NLRP3 inflammasome, and NFκB activation. RESULTS GBS evoked a strong inflammatory phenotype characterized by the release of inflammatory cytokines (TNFα, IL-1β, IL-6 (P ≤ 0.05), NLRP3 inflammasome assembly (P ≤ 0.0005), and NFκB activation (P ≤ 0.05). Pharmacological inhibition of PKD suppressed these responses, newly implicating a role for PKD in mediating immune responses of primary human placental macrophages to GBS. CONCLUSION PKD plays a critical role in mediating placental macrophage inflammatory activation in response to GBS infection.
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Affiliation(s)
- Jessica A. Sutton
- Department of Microbiology and Immunology, Meharry Medical College School of Medicine, Nashville, TN, 37208, USA
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lisa M. Rogers
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Beverly Dixon
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Leslie Kirk
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ryan Doster
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Holly M. Algood
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee, U.S.A
| | - Jennifer A. Gaddy
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee, U.S.A
| | - Rebecca Flaherty
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - David M. Aronoff
- Department of Microbiology and Immunology, Meharry Medical College School of Medicine, Nashville, TN, 37208, USA
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
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Armistead B, Oler E, Adams Waldorf K, Rajagopal L. The Double Life of Group B Streptococcus: Asymptomatic Colonizer and Potent Pathogen. J Mol Biol 2019; 431:2914-2931. [PMID: 30711542 DOI: 10.1016/j.jmb.2019.01.035] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 12/22/2022]
Abstract
Group B streptococcus (GBS) is a β-hemolytic gram-positive bacterium that colonizes the lower genital tract of approximately 18% of women globally as an asymptomatic member of the gastrointestinal and/or vaginal flora. If established in other host niches, however, GBS is highly pathogenic. During pregnancy, ascending GBS infection from the vagina to the intrauterine space is associated with preterm birth, stillbirth, and fetal injury. In addition, vertical transmission of GBS during or after birth results in life-threatening neonatal infections, including pneumonia, sepsis, and meningitis. Although the mechanisms by which GBS traffics from the lower genital tract to vulnerable host niches are not well understood, recent advances have revealed that many of the same bacterial factors that promote asymptomatic vaginal carriage also facilitate dissemination and virulence. Furthermore, highly pathogenic GBS strains have acquired unique factors that enhance survival in invasive niches. Several host factors also exist that either subdue GBS upon vaginal colonization or alternatively permit invasive infection. This review summarizes the GBS and host factors involved in GBS's state as both an asymptomatic colonizer and an invasive pathogen. Gaining a better understanding of these mechanisms is key to overcoming the challenges associated with vaccine development and identification of novel strategies to mitigate GBS virulence.
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Affiliation(s)
- Blair Armistead
- Department of Global Health, University of Washington, Seattle 98195, WA, USA; Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle 98101, WA, USA
| | - Elizabeth Oler
- Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle 98195, WA, USA
| | - Kristina Adams Waldorf
- Department of Global Health, University of Washington, Seattle 98195, WA, USA; Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle 98195, WA, USA; Center for Innate Immunity and Immune Disease, University of Washington, Seattle 98109, WA, USA; Sahlgrenska Academy, Gothenburg University, Gothenburg 413 90, Sweden
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle 98195, WA, USA; Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle 98101, WA, USA; Department of Pediatrics, University of Washington School of Medicine, Seattle 98195, WA, USA.
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47
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Association between preterm birth and genital colonization with Mycoplasma – literature review. GINECOLOGIA.RO 2019. [DOI: 10.26416/gine.24.2.2019.2375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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48
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Yadeta TA, Worku A, Egata G, Seyoum B, Marami D, Berhane Y. Maternal group B Streptococcus recto vaginal colonization increases the odds of stillbirth: evidence from Eastern Ethiopia. BMC Pregnancy Childbirth 2018; 18:410. [PMID: 30340553 PMCID: PMC6194672 DOI: 10.1186/s12884-018-2044-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 10/05/2018] [Indexed: 12/21/2022] Open
Abstract
Background Group B Streptococcus (GBS) causes a significant number of stillbirths. Despite this, there is little documented information on the association between stillbirth and pregnant women’s GBS recto vaginal colonization in Sub Saharan Africa. As such, this study was aimed at identifying the association between stillbirth and pregnant women’s GBS recto vaginal colonization in Eastern Ethiopia. Methods A health facility-based cross-sectional study was conducted among 1688 pregnant women who came for delivery service in Harar town, Eastern Ethiopia between June to October in 2016. Data were collected using a pre-tested structured questionnaire and checklist (which utilize clinical record). Group B streptococcus positivity of the pregnant women was confirmed by culture of recto vaginal swab using selective media. The association between GBS colonization and stillbirth was examined using multivariable logistic regression analysis. A statistical significance was declared at p-value ≤0.05. Results Of the 1688 pregnant women who participated in the study, 144 had stillbirths, representing a prevalence of 8.53% [(95% CI: (7.19, 9.86)]. Group B Streptococcus colonization at birth was detected in 231 women (13.68%; 95% CI 12.04, 15.32). Of these 144 stillbirths 59 (40.97%) were from colonized mothers and 72(59.03%) were from non-colonized mothers. Of these 59 stillbirth from colonized mothers, 32(54.23%) were intrapartum stillbirth, 27(45.77%) were antepartum stillbirth occur before exposed to intrapartum antibiotic prophylaxis (IAP). After controlling for potential confounders, the odds of having a stillbirth were 8.93 times higher among recto vaginal GBS colonized pregnant women [AOR = 8.93; 95% CI; (5.47, 14.56)]. Conclusions This study demonstrated a significant association between maternal recto vaginal GBS colonization and stillbirth. Efforts to reduce stillbirth need to consider prevention of GBS colonization among pregnant women. Maternal vaccination may provide a feasible strategy to reduce stillbirth due to GBS.
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Affiliation(s)
- Tesfaye Assebe Yadeta
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia. .,School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia. .,Department of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia.
| | - Alemayehu Worku
- Department of Epidemiology and Biostatistics, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Gudina Egata
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Berhanu Seyoum
- Department of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Dadi Marami
- Department of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Yemane Berhane
- Department of Epidemiology, Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
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49
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Suff N, Karda R, Diaz JA, Ng J, Baruteau J, Perocheau D, Tangney M, Taylor PW, Peebles D, Buckley SMK, Waddington SN. Ascending Vaginal Infection Using Bioluminescent Bacteria Evokes Intrauterine Inflammation, Preterm Birth, and Neonatal Brain Injury in Pregnant Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:2164-2176. [PMID: 30036519 PMCID: PMC6168615 DOI: 10.1016/j.ajpath.2018.06.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 12/11/2022]
Abstract
Preterm birth is a serious global health problem and the leading cause of infant death before 5 years of age. At least 40% of cases are associated with infection. The most common way for pathogens to access the uterine cavity is by ascending from the vagina. Bioluminescent pathogens have revolutionized the understanding of infectious diseases. We hypothesized that bioluminescent Escherichia coli can be used to track and monitor ascending vaginal infections. Two bioluminescent strains were studied: E. coli K12 MG1655-lux, a nonpathogenic laboratory strain, and E. coli K1 A192PP-lux2, a pathogenic strain capable of causing neonatal meningitis and sepsis in neonatal rats. On embryonic day 16, mice received intravaginal E. coli K12, E. coli K1, or phosphate-buffered saline followed by whole-body bioluminescent imaging. In both cases, intravaginal delivery of E. coli K12 or E. coli K1 led to bacterial ascension into the uterine cavity, but only E. coli K1 induced preterm parturition. Intravaginal administration of E. coli K1 significantly reduced the proportion of pups born alive compared with E. coli K12 and phosphate-buffered saline controls. However, in both groups of viable pups born after bacterial inoculation, there was evidence of comparable brain inflammation by postnatal day 6. This study ascribes specific mechanisms by which exposure to intrauterine bacteria leads to premature delivery and neurologic inflammation in neonates.
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Affiliation(s)
- Natalie Suff
- Gene Transfer Technology Group, University College London, London, United Kingdom; Preterm Birth Group, Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - Rajvinder Karda
- Gene Transfer Technology Group, University College London, London, United Kingdom
| | - Juan A Diaz
- Gene Transfer Technology Group, University College London, London, United Kingdom
| | - Joanne Ng
- Gene Transfer Technology Group, University College London, London, United Kingdom
| | - Julien Baruteau
- Gene Transfer Technology Group, University College London, London, United Kingdom; Department of Metabolic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Dany Perocheau
- Gene Transfer Technology Group, University College London, London, United Kingdom
| | - Mark Tangney
- SynBio Centre, University College Cork, Cork, Ireland
| | - Peter W Taylor
- School of Pharmacy, University College London, London, United Kingdom
| | - Donald Peebles
- Preterm Birth Group, Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - Suzanne M K Buckley
- Gene Transfer Technology Group, University College London, London, United Kingdom.
| | - Simon N Waddington
- Gene Transfer Technology Group, University College London, London, United Kingdom; MRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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50
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Díaz-Dinamarca DA, Jerias JI, Soto DA, Soto JA, Díaz NV, Leyton YY, Villegas RA, Kalergis AM, Vásquez AE. The Optimisation of the Expression of Recombinant Surface Immunogenic Protein of Group B Streptococcus in Escherichia coli by Response Surface Methodology Improves Humoral Immunity. Mol Biotechnol 2018; 60:215-225. [PMID: 29442290 DOI: 10.1007/s12033-018-0065-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Group B Streptococcus (GBS) is the leading cause of neonatal meningitis and a common pathogen in livestock and aquaculture industries around the world. Conjugate polysaccharide and protein-based vaccines are under development. The surface immunogenic protein (SIP) is a conserved protein in all GBS serotypes and has been shown to be a good target for vaccine development. The expression of recombinant proteins in Escherichia coli cells has been shown to be useful in the development of vaccines, and the protein purification is a factor affecting their immunogenicity. The response surface methodology (RSM) and Box-Behnken design can optimise the performance in the expression of recombinant proteins. However, the biological effect in mice immunised with an immunogenic protein that is optimised by RSM and purified by low-affinity chromatography is unknown. In this study, we used RSM for the optimisation of the expression of the rSIP, and we evaluated the SIP-specific humoral response and the property to decrease the GBS colonisation in the vaginal tract in female mice. It was observed by NI-NTA chromatography that the RSM increases the yield in the expression of rSIP, generating a better purification process. This improvement in rSIP purification suggests a better induction of IgG anti-SIP immune response and a positive effect in the decreased GBS intravaginal colonisation. The RSM applied to optimise the expression of recombinant proteins with immunogenic capacity is an interesting alternative in the evaluation of vaccines in preclinical phase, which could improve their immune response.
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Affiliation(s)
- Diego A Díaz-Dinamarca
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile.,Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millenium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - José I Jerias
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile
| | - Daniel A Soto
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile
| | - Jorge A Soto
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile.,Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millenium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Natalia V Díaz
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile
| | - Yessica Y Leyton
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile
| | - Rodrigo A Villegas
- Departamento de Asuntos Científicos, Instituto de Salud Pública de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Millenium Institute on Immunology and Immunotherapy, Santiago, Chile.,Departamento de Endocrinología, Facultad de Medicina Pontificia, Universidad Católica de Chile, Santiago, Chile
| | - Abel E Vásquez
- Sección Biotecnología, Instituto de Salud Pública de Chile, Santiago, Chile. .,Facultad de Ciencia, Universidad San Sebastián, Providencia, Santiago, Chile.
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