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Padron GC, Shuppara AM, Sharma A, Koch MD, Palalay JJS, Radin JN, Kehl-Fie TE, Imlay JA, Sanfilippo JE. Shear rate sensitizes bacterial pathogens to H 2O 2 stress. Proc Natl Acad Sci U S A 2023; 120:e2216774120. [PMID: 36888662 PMCID: PMC10089187 DOI: 10.1073/pnas.2216774120] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/18/2023] [Indexed: 03/09/2023] Open
Abstract
Cells regularly experience fluid flow in natural systems. However, most experimental systems rely on batch cell culture and fail to consider the effect of flow-driven dynamics on cell physiology. Using microfluidics and single-cell imaging, we discover that the interplay of physical shear rate (a measure of fluid flow) and chemical stress trigger a transcriptional response in the human pathogen Pseudomonas aeruginosa. In batch cell culture, cells protect themselves by quickly scavenging the ubiquitous chemical stressor hydrogen peroxide (H2O2) from the media. In microfluidic conditions, we observe that cell scavenging generates spatial gradients of H2O2. High shear rates replenish H2O2, abolish gradients, and generate a stress response. Combining mathematical simulations and biophysical experiments, we find that flow triggers an effect like "wind-chill" that sensitizes cells to H2O2 concentrations 100 to 1,000 times lower than traditionally studied in batch cell culture. Surprisingly, the shear rate and H2O2 concentration required to generate a transcriptional response closely match their respective values in the human bloodstream. Thus, our results explain a long-standing discrepancy between H2O2 levels in experimental and host environments. Finally, we demonstrate that the shear rate and H2O2 concentration found in the human bloodstream trigger gene expression in the blood-relevant human pathogen Staphylococcus aureus, suggesting that flow sensitizes bacteria to chemical stress in natural environments.
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Affiliation(s)
- Gilberto C. Padron
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Alexander M. Shuppara
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Anuradha Sharma
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Matthias D. Koch
- Department of Biology, Texas A&M University, College Station, TX77843
| | | | - Jana N. Radin
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Thomas E. Kehl-Fie
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL61801
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - James A. Imlay
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Joseph E. Sanfilippo
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
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Talà A, Calcagnile M, Resta SC, Pennetta A, De Benedetto GE, Alifano P. Thiostrepton, a resurging drug inhibiting the stringent response to counteract antibiotic-resistance and expression of virulence determinants in Neisseria gonorrhoeae. Front Microbiol 2023; 14:1104454. [PMID: 36910221 PMCID: PMC9998046 DOI: 10.3389/fmicb.2023.1104454] [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: 11/21/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023] Open
Abstract
Due to the increased resistance to all available antibiotics and the lack of vaccines, Neisseria gonorrhoeae (the gonococcus) poses an urgent threat. Although the mechanisms of virulence and antibiotic resistance have been largely investigated in this bacterium, very few studies have addressed the stringent response (SR) that in pathogenic bacteria controls the expression of genes involved in host-pathogen interaction and tolerance and persistence toward antibiotics. In this study, the results of the transcriptome analysis of a clinical isolate of N. gonorrhoeae, after induction of the SR by serine hydroxamate, provided us with an accurate list of genes that are transcriptionally modulated during the SR. The list includes genes associated with metabolism, cellular machine functions, host-pathogen interaction, genome plasticity, and antibiotic tolerance and persistence. Moreover, we found that the artificial induction of the SR in N. gonorrhoeae by serine hydroxamate is prevented by thiostrepton, a thiopeptide antibiotic that is known to interact with ribosomal protein L11, thereby inhibiting functions of EF-Tu and EF-G, and binding of pppGpp synthase I (RelA) to ribosome upon entry of uncharged tRNA. We found that N. gonorrhoeae is highly sensitive to thiostrepton under in vitro conditions, and that thiostrepton, in contrast to other antibiotics, does not induce tolerance or persistence. Finally, we observed that thiostrepton attenuated the expression of key genes involved in the host-pathogen interaction. These properties make thiostrepton a good drug candidate for dampening bacterial virulence and preventing antibiotic tolerance and persistence. The ongoing challenge is to increase the bioavailability of thiostrepton through the use of chemistry and nanotechnology.
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Affiliation(s)
- Adelfia Talà
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Matteo Calcagnile
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Silvia Caterina Resta
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Antonio Pennetta
- Laboratory of Analytical and Isotopic Mass Spectrometry, Department of Cultural Heritage, University of Salento, Lecce, Italy
| | - Giuseppe Egidio De Benedetto
- Laboratory of Analytical and Isotopic Mass Spectrometry, Department of Cultural Heritage, University of Salento, Lecce, Italy
| | - Pietro Alifano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
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Hu LI, Stohl EA, Seifert HS. The Neisseria gonorrhoeae type IV pilus promotes resistance to hydrogen peroxide- and LL-37-mediated killing by modulating the availability of intracellular, labile iron. PLoS Pathog 2022; 18:e1010561. [PMID: 35714158 PMCID: PMC9246397 DOI: 10.1371/journal.ppat.1010561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 06/30/2022] [Accepted: 04/29/2022] [Indexed: 11/20/2022] Open
Abstract
The Neisseria gonorrhoeae Type IV pilus is a multifunctional, dynamic fiber involved in host cell attachment, DNA transformation, and twitching motility. We previously reported that the N. gonorrhoeae pilus is also required for resistance against hydrogen peroxide-, antimicrobial peptide LL-37-, and non-oxidative, neutrophil-mediated killing. We tested whether the hydrogen peroxide, LL-37, and neutrophil hypersensitivity phenotypes in non-piliated N. gonorrhoeae could be due to elevated iron levels. Iron chelation in the growth medium rescued a nonpiliated pilE mutant from both hydrogen peroxide- and antimicrobial peptide LL-37-mediated killing, suggesting these phenotypes are related to iron availability. We used the antibiotic streptonigrin, which depends on free cytoplasmic iron and oxidation to kill bacteria, to determine whether piliation affected intracellular iron levels. Several non-piliated, loss-of-function mutants were more sensitive to streptonigrin killing than the piliated parental strain. Consistent with the idea that higher available iron levels in the under- and non-piliated strains were responsible for the higher streptonigrin sensitivity, iron limitation by desferal chelation restored resistance to streptonigrin in these strains and the addition of iron restored the sensitivity to streptonigrin killing. The antioxidants tiron and dimethylthiourea rescued the pilE mutant from streptonigrin-mediated killing, suggesting that the elevated labile iron pool in non-piliated bacteria leads to streptonigrin-dependent reactive oxygen species production. These antioxidants did not affect LL-37-mediated killing. We confirmed that the pilE mutant is not more sensitive to other antibiotics showing that the streptonigrin phenotypes are not due to general bacterial envelope disruption. The total iron content of the cell was unaltered by piliation when measured using ICP-MS suggesting that only the labile iron pool is affected by piliation. These results support the hypothesis that piliation state affects N. gonorrhoeae iron homeostasis and influences sensitivity to various host-derived antimicrobial agents. Neisseria gonorrhoeae is a bacterium that causes the sexually transmitted infection, gonorrhea. The bacteria express a fiber on their surface called a pilus that mediates many interactions of the bacterial cell with host cells and tissues. The ability to resist killing by white cells is one important ability that N. gonorrhoeae uses to allow infection of otherwise healthy people. We show here that the pilus help resist white cell killing by modulating the levels of iron within the bacterial cell.
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Affiliation(s)
- Linda I. Hu
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Elizabeth A. Stohl
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - H Steven Seifert
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail:
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Sunkavalli A, McClure R, Genco C. Molecular Regulatory Mechanisms Drive Emergent Pathogenetic Properties of Neisseria gonorrhoeae. Microorganisms 2022; 10:922. [PMID: 35630366 PMCID: PMC9147433 DOI: 10.3390/microorganisms10050922] [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: 03/28/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 12/05/2022] Open
Abstract
Neisseria gonorrhoeae is the causative agent of the sexually transmitted infection (STI) gonorrhea, with an estimated 87 million annual cases worldwide. N. gonorrhoeae predominantly colonizes the male and female genital tract (FGT). In the FGT, N. gonorrhoeae confronts fluctuating levels of nutrients and oxidative and non-oxidative antimicrobial defenses of the immune system, as well as the resident microbiome. One mechanism utilized by N. gonorrhoeae to adapt to this dynamic FGT niche is to modulate gene expression primarily through DNA-binding transcriptional regulators. Here, we describe the major N. gonorrhoeae transcriptional regulators, genes under their control, and how these regulatory processes lead to pathogenic properties of N. gonorrhoeae during natural infection. We also discuss the current knowledge of the structure, function, and diversity of the FGT microbiome and its influence on gonococcal survival and transcriptional responses orchestrated by its DNA-binding regulators. We conclude with recent multi-omics data and modeling tools and their application to FGT microbiome dynamics. Understanding the strategies utilized by N. gonorrhoeae to regulate gene expression and their impact on the emergent characteristics of this pathogen during infection has the potential to identify new effective strategies to both treat and prevent gonorrhea.
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Affiliation(s)
- Ashwini Sunkavalli
- Department of Immunology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA;
| | - Ryan McClure
- Pacific Northwest National Laboratory, Richland, WA 99354, USA;
| | - Caroline Genco
- Department of Immunology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA;
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Grossman AS, Mauer TJ, Forest KT, Goodrich-Blair H. A Widespread Bacterial Secretion System with Diverse Substrates. mBio 2021; 12:e0195621. [PMID: 34399622 PMCID: PMC8406197 DOI: 10.1128/mbio.01956-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 07/09/2021] [Indexed: 01/26/2023] Open
Abstract
In host-associated bacteria, surface and secreted proteins mediate acquisition of nutrients, interactions with host cells, and specificity of tissue localization. In Gram-negative bacteria, the mechanism by which many proteins cross and/or become tethered to the outer membrane remains unclear. The domain of unknown function 560 (DUF560) occurs in outer membrane proteins throughout Proteobacteria and has been implicated in host-bacterium interactions and lipoprotein surface exposure. We used sequence similarity networking to reveal three subfamilies of DUF560 homologs. One subfamily includes those DUF560 proteins experimentally characterized thus far: NilB, a host range determinant of the nematode-mutualist Xenorhabdus nematophila, and the surface lipoprotein assembly modulators Slam1 and Slam2, which facilitate lipoprotein surface exposure in Neisseria meningitidis (Y. Hooda, C. C. Lai, A. Judd, C. M. Buckwalter, et al., Nat Microbiol 1:16009, 2016, https://doi.org/10.1038/nmicrobiol.2016.9; Y. Hooda, C. C. L. Lai, T. F. Moraes, Front Cell Infect Microbiol 7:207, 2017, https://doi.org/10.3389/fcimb.2017.00207). We show that DUF560 proteins from a second subfamily facilitate secretion of soluble, nonlipidated proteins across the outer membrane. Using in silico analysis, we demonstrate that DUF560 gene complement correlates with bacterial environment at a macro level and host association at a species level. The DUF560 protein superfamily represents a newly characterized Gram-negative secretion system capable of lipoprotein surface exposure and soluble protein secretion with conserved roles in facilitating symbiosis. In light of these data, we propose that it be titled the type 11 secretion system (TXISS). IMPORTANCE The microbial constituency of a host-associated microbiome emerges from a complex physical and chemical interplay of microbial colonization factors, host surface conditions, and host immunological responses. To fill unique niches within a host, bacteria encode surface and secreted proteins that enable interactions with and responses to the host and co-occurring microbes. Bioinformatic predictions of putative bacterial colonization factor localization and function facilitate hypotheses about the potential of bacteria to engage in pathogenic, mutualistic, or commensal activities. This study uses publicly available genome sequence data alongside experimental results from Xenorhabdus nematophila to demonstrate a role for DUF560 family proteins in secretion of bacterial effectors of host interactions. Our research delineates a broadly distributed family of proteins and enables more accurate predictions of the localization of colonization factors throughout Proteobacteria.
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Affiliation(s)
- Alex S. Grossman
- University of Tennessee—Knoxville, Department of Microbiology, Knoxville, Tennessee, USA
| | - Terra J. Mauer
- University of Wisconsin—Madison, Department of Bacteriology, Madison, Wisconsin, USA
| | - Katrina T. Forest
- University of Wisconsin—Madison, Department of Bacteriology, Madison, Wisconsin, USA
| | - Heidi Goodrich-Blair
- University of Tennessee—Knoxville, Department of Microbiology, Knoxville, Tennessee, USA
- University of Wisconsin—Madison, Department of Bacteriology, Madison, Wisconsin, USA
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6
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das Neves Selis N, de Oliveira HBM, Leão HF, Dos Anjos YB, Sampaio BA, Correia TML, Almeida CF, Pena LSC, Reis MM, Brito TLS, Brito LF, Campos GB, Timenetsky J, Cruz MP, Rezende RP, Romano CC, da Costa AM, Yatsuda R, Uetanabaro APT, Marques LM. Lactiplantibacillus plantarum strains isolated from spontaneously fermented cocoa exhibit potential probiotic properties against Gardnerella vaginalis and Neisseria gonorrhoeae. BMC Microbiol 2021; 21:198. [PMID: 34187371 PMCID: PMC8243870 DOI: 10.1186/s12866-021-02264-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/15/2021] [Indexed: 01/24/2023] Open
Abstract
Background Probiotics are important tools in therapies against vaginal infections and can assist traditional antibiotic therapies in restoring healthy microbiota. Recent research has shown that microorganisms belonging to the genus Lactobacillus have probiotic potential. Thus, this study evaluated the potential in vitro probiotic properties of three strains of Lactiplantibacillus plantarum, isolated during the fermentation of high-quality cocoa, against Gardnerella vaginalis and Neisseria gonorrhoeae. Strains were evaluated for their physiological, safety, and antimicrobial characteristics. Results The hydrophobicity of L. plantarum strains varied from 26.67 to 91.67%, and their autoaggregation varied from 18.10 to 30.64%. The co-aggregation of L. plantarum strains with G. vaginalis ranged from 14.73 to 16.31%, and from 29.14 to 45.76% with N. gonorrhoeae. All L. plantarum strains could moderately or strongly produce biofilms. L. plantarum strains did not show haemolytic activity and were generally sensitive to the tested antimicrobials. All lactobacillus strains were tolerant to heat and pH resistance tests. All three strains of L. plantarum showed antimicrobial activity against the tested pathogens. The coincubation of L. plantarum strains with pathogens showed that the culture pH remained below 4.5 after 24 h. All cell-free culture supernatants (CFCS) demonstrated activity against the two pathogens tested, and all L. plantarum strains produced hydrogen peroxide. CFCS characterisation in conjunction with gas chromatography revealed that organic acids, especially lactic acid, were responsible for the antimicrobial activity against the pathogens evaluated. Conclusion The three strains of L. plantarum presented significant probiotic characteristics against the two pathogens of clinical importance. In vitro screening identified strong probiotic candidates for in vivo studies for the treatment of vaginal infections.
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Affiliation(s)
- Nathan das Neves Selis
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil
| | - Hellen Braga Martins de Oliveira
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil
| | - Hiago Ferreira Leão
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Yan Bento Dos Anjos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Beatriz Almeida Sampaio
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Thiago Macêdo Lopes Correia
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Carolline Florentino Almeida
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Larissa Silva Carvalho Pena
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Mariane Mares Reis
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Thamara Louisy Santos Brito
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Laís Ferraz Brito
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Guilherme Barreto Campos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Jorge Timenetsky
- Instituto de Ciências Biomédicas, Universidade de São Paulo, Avenida Professor Lineu Prestes, 2415, CEP 05508-900, São Paulo, SP, Brazil
| | - Mariluze Peixoto Cruz
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Rachel Passos Rezende
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil
| | - Carla Cristina Romano
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil
| | - Andréa Miura da Costa
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil.,Departamento de Ciências Biológicas, Laboratório de Microbiologia da Agroindústria, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil
| | - Regiane Yatsuda
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil
| | - Ana Paula Trovatti Uetanabaro
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil.,Departamento de Ciências Biológicas, Laboratório de Microbiologia da Agroindústria, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil
| | - Lucas Miranda Marques
- Programa de Pós-Graduação em Biologia e Biotecnologia de Microrganismos, Pavilhão Max de Menezes, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Salobrinho, Rodovia Jorge Amado, Km 16, CEP 45662-900, Ilhéus, BA, Brazil. .,Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Campus Anísio Teixeira, Rua Hormindo Barros, 58, CEP 45029-094, Vitória da Conquista, BA, Brazil.
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Gardnerella vaginalis and Neisseria gonorrhoeae Are Effectively Inhibited by Lactobacilli with Probiotic Properties Isolated from Brazilian Cupuaçu ( Theobroma grandiflorum) Fruit. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6626249. [PMID: 33997030 PMCID: PMC8102102 DOI: 10.1155/2021/6626249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/04/2021] [Accepted: 04/23/2021] [Indexed: 02/01/2023]
Abstract
In recent years, certain Lactobacillus sp. have emerged in health care as an alternative therapy for various diseases. Based on this, this study is aimed at evaluating in vitro the potential probiotics of five lactobacilli strains isolated from pulp of cupuaçu fruit fermentation against Gardnerella vaginalis and Neisseria gonorrhoeae. Our lactobacilli strains were classified as safe for use in humans, and they were tolerant to heat and pH. Our strains were biofilm producers, while hydrophobicity and autoaggregation varied from 13% to 86% and 13% to 25%, respectively. The coaggregation of lactobacilli used in this study with G. vaginalis and N. gonorrhoeae ranged from 15% to 36% and 32% to 52%, respectively. Antimicrobial activity was present in all tested Lactobacillus strains against both pathogens, and the growth of pathogens in coculture was reduced by the presence of our lactobacilli. Also, all tested lactobacilli reduced the pH of the culture, even in incubation with pathogens after 24 hours. The cell-free culture supernatants (CFCS) of all five lactobacilli demonstrated activity against the two pathogens with a halo presence and CFCS characterization assay together with gas chromatography revealed that lactic acid was the most abundant organic acid in the samples (50% to 62%). Our results demonstrated that the organic acid production profile is strain-specific. This study revealed that cupuaçu is a promising source of microorganisms with probiotic properties against genital pathogens. We demonstrated by in vitro tests that our Lactobacillus strains have probiotic properties. However, the absence of in vivo tests is a limitation of our work due to the need to evaluate the interaction of our lactobacilli with pathogens in the vaginal mucosa. We believe that these findings may be useful in developing a product containing our lactobacilli and their supernatants in order to support with vaginal health.
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McClure R, Sunkavalli A, Balzano PM, Massari P, Cho C, Nauseef WM, Apicella MA, Genco CA. Global Network Analysis of Neisseria gonorrhoeae Identifies Coordination between Pathways, Processes, and Regulators Expressed during Human Infection. mSystems 2020; 5:e00729-19. [PMID: 32019834 PMCID: PMC7002116 DOI: 10.1128/msystems.00729-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/19/2019] [Indexed: 12/12/2022] Open
Abstract
Neisseria gonorrhoeae is a Gram-negative diplococcus that is responsible for the sexually transmitted infection gonorrhea, a high-morbidity disease in the United States and worldwide. Over the past several years, N. gonorrhoeae strains resistant to antibiotics used to treat this infection have begun to emerge across the globe. Thus, new treatment strategies are needed to combat this organism. Here, we utilized N. gonorrhoeae transcriptomic data sets, including those obtained from natural infection of the human genital tract, to infer the first global gene coexpression network of this pathogen. Interrogation of this network revealed genes central to the network that are likely critical for gonococcal growth, metabolism, and virulence, including genes encoding hypothetical proteins expressed during mucosal infection. In addition, network analysis revealed overlap in the response of N. gonorrhoeae to incubation with neutrophils and exposure to hydrogen peroxide stress in vitro Network analysis also identified new targets of the gonococcal global regulatory protein Fur, while examination of the network neighborhood of genes allowed us to assign additional putative categories to several proteins. Collectively, the characterization of the first gene coexpression network for N. gonorrhoeae described here has revealed new regulatory pathways and new categories for proteins and has shown how processes important to gonococcal infection in both men and women are linked. This information fills a critical gap in our understanding of virulence strategies of this obligate human pathogen and will aid in the development of new treatment strategies for gonorrhea.IMPORTANCE Neisseria gonorrhoeae is the causative agent of the sexually transmitted infection (STI) gonorrhea, a disease with high morbidity worldwide with an estimated 87 million cases annually. Current therapeutic and pharmacologic approaches to treat gonorrhea have been compromised by increased antibiotic resistance worldwide, including to the most recent FDA-approved antibiotic. New treatment strategies are urgently needed to combat this organism. In this study, we used network analysis to interrogate and define the coordination of pathways and processes in N. gonorrhoeae An analysis of the gonococcal network was also used to assign categories to genes and to expand our understanding of regulatory strategies. Network analysis provides important insights into pathogenic mechanisms of this organism that will guide the design of new strategies for disease treatment.
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Affiliation(s)
- Ryan McClure
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Ashwini Sunkavalli
- Department of Immunology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Phillip M Balzano
- Department of Immunology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Paola Massari
- Department of Immunology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Christine Cho
- Department of Internal Medicine, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - William M Nauseef
- Department of Internal Medicine, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Michael A Apicella
- Department of Internal Medicine, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Caroline A Genco
- Department of Immunology, Tufts University School of Medicine, Boston, Massachusetts, USA
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Transcriptional regulation of a gonococcal gene encoding a virulence factor (L-lactate permease). PLoS Pathog 2019; 15:e1008233. [PMID: 31860664 PMCID: PMC6957213 DOI: 10.1371/journal.ppat.1008233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/13/2020] [Accepted: 11/22/2019] [Indexed: 12/16/2022] Open
Abstract
GdhR is a GntR-type regulator of Neisseria gonorrhoeae encoded by a gene (gdhR) belonging to the MtrR regulon, which comprises multiple genes required for antibiotic resistance such as the mtrCDE efflux pump genes. In previous work we showed that loss of gdhR results in enhanced gonococcal fitness in a female mouse model of lower genital tract infection. Here, we used RNA-Seq to perform a transcriptional profiling study to determine the GdhR regulon. GdhR was found to regulate the expression of 2.3% of all the genes in gonococcal strain FA19, of which 39 were activated and 11 were repressed. Within the GdhR regulon we found that lctP, which encodes a unique L-lactate transporter and has been associated with gonococcal pathogenesis, was the highest of GdhR-repressed genes. By using in vitro transcription and DNase I footpriting assays we mapped the lctP transcriptional start site (TSS) and determined that GdhR directly inhibits transcription by binding to an inverted repeat sequence located 9 bases downstream of the lctP TSS. Epistasis analysis revealed that, while loss of lctP increased susceptibility of gonococci to hydrogen peroxide (H2O2) the loss of gdhR enhanced resistance; however, this GdhR-endowed property was reversed in a double gdhR lctP null mutant. We assessed the effect of different carbon sources on lctP expression and found that D-glucose, but not L-lactate or pyruvate, repressed lctP expression within a physiological concentration range but in a GdhR-independent manner. Moreover, we found that adding glucose to the medium enhanced susceptibility of gonococci to hydrogen peroxide. We propose a model for the role of lctP regulation via GdhR and glucose in the pathogenesis of N. gonorrhoeae.
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Zhu T, McClure R, Harrison OB, Genco C, Massari P. Integrated Bioinformatic Analyses and Immune Characterization of New Neisseria gonorrhoeae Vaccine Antigens Expressed during Natural Mucosal Infection. Vaccines (Basel) 2019; 7:E153. [PMID: 31627489 PMCID: PMC6963464 DOI: 10.3390/vaccines7040153] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/11/2019] [Accepted: 10/14/2019] [Indexed: 02/07/2023] Open
Abstract
There is an increasingly severe trend of antibiotic-resistant Neisseria gonorrhoeae strains worldwide and new therapeutic strategies are needed against this sexually-transmitted pathogen. Despite the urgency, progress towards a gonococcal vaccine has been slowed by a scarcity of suitable antigens, lack of correlates of protection in humans and limited animal models of infection. N. gonorrhoeae gene expression levels in the natural human host does not reflect expression in vitro, further complicating in vitro-basedvaccine analysis platforms. We designed a novel candidate antigen selection strategy (CASS), based on a reverse vaccinology-like approach coupled with bioinformatics. We utilized the CASS to mine gonococcal proteins expressed during human mucosal infection, reported in our previous studies, and focused on a large pool of hypothetical proteins as an untapped source of potential new antigens. Via two discovery and analysis phases (DAP), we identified 36 targets predicted to be immunogenic, membrane-associated proteins conserved in N. gonorrhoeae and suitable for recombinant expression. Six initial candidates were produced and used to immunize mice. Characterization of the immune responses indicated cross-reactive antibodies and serum bactericidal activity against different N. gonorrhoeae strains. These results support the CASS as a tool for the discovery of new vaccine candidates.
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Affiliation(s)
- Tianmou Zhu
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Ryan McClure
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
| | - Odile B Harrison
- Department of Zoology, University of Oxford, Oxford OX1 3SY, UK.
| | - Caroline Genco
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Paola Massari
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA.
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Interaction between Streptococcus pneumoniae and Staphylococcus aureus Generates ·OH Radicals That Rapidly Kill Staphylococcus aureus Strains. J Bacteriol 2019; 201:JB.00474-19. [PMID: 31405914 DOI: 10.1128/jb.00474-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 08/08/2019] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pneumoniae rapidly kills Staphylococcus aureus by producing membrane-permeable hydrogen peroxide (H2O2). The mechanism by which S. pneumoniae-produced H2O2 mediates S. aureus killing was investigated. An in vitro model that mimicked S. pneumoniae-S. aureus contact during colonization of the nasopharynx demonstrated that S. aureus killing required outcompeting densities of S. pneumoniae Compared to the wild-type strain, isogenic S. pneumoniae ΔlctO and S. pneumoniae ΔspxB, both deficient in production of H2O2, required increased density to kill S. aureus While residual H2O2 activity produced by single mutants was sufficient to eradicate S. aureus, an S. pneumoniae ΔspxB ΔlctO double mutant was unable to kill S. aureus A collection of 20 diverse methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains showed linear sensitivity (R 2 = 0.95) for S. pneumoniae killing, but the same strains had different susceptibilities when challenged with pure H2O2 (5 mM). There was no association between the S. aureus clonal complex and sensitivity to either S. pneumoniae or H2O2 To kill S. aureus, S. pneumoniae produced ∼180 μM H2O2 within 4 h of incubation, while the killing-defective S. pneumoniae ΔspxB and S. pneumoniae ΔspxB ΔlctO mutants produced undetectable levels. Remarkably, a sublethal dose (1 mM) of pure H2O2 incubated with S. pneumoniae ΔspxB eradicated diverse S. aureus strains, suggesting that S. pneumoniae bacteria may facilitate conversion of H2O2 to a hydroxyl radical (·OH). Accordingly, S. aureus killing was completely blocked by incubation with scavengers of ·OH radicals, dimethyl sulfoxide (Me2SO), thiourea, or sodium salicylate. The ·OH was detected in S. pneumoniae cells by spin trapping and electron paramagnetic resonance. Therefore, S. pneumoniae produces H2O2, which is rapidly converted to a more potent oxidant, hydroxyl radicals, to rapidly intoxicate S. aureus strains.IMPORTANCE Streptococcus pneumoniae strains produce hydrogen peroxide (H2O2) to kill bacteria in the upper airways, including pathogenic Staphylococcus aureus strains. The targets of S. pneumoniae-produced H2O2 have not been discovered, in part because of a lack of knowledge about the underlying molecular mechanism. We demonstrated that an increased density of S. pneumoniae kills S. aureus by means of H2O2 produced by two enzymes, SpxB and LctO. We discovered that SpxB/LctO-produced H2O2 is converted into a hydroxyl radical (·OH) that rapidly intoxicates and kills S. aureus We successfully inhibited the toxicity of ·OH with three different scavengers and detected ·OH in the supernatant. The target(s) of the hydroxyl radicals represents a new alternative for the development of antimicrobials against S. aureus infections.
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Prister LL, Ozer EA, Cahoon LA, Seifert HS. Transcriptional initiation of a small RNA, not R-loop stability, dictates the frequency of pilin antigenic variation in Neisseria gonorrhoeae. Mol Microbiol 2019; 112:1219-1234. [PMID: 31338863 DOI: 10.1111/mmi.14356] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2019] [Indexed: 02/06/2023]
Abstract
Neisseria gonorrhoeae, the sole causative agent of gonorrhea, constitutively undergoes diversification of the Type IV pilus. Gene conversion occurs between one of the several donor silent copies located in distinct loci and the recipient pilE gene, encoding the major pilin subunit of the pilus. A guanine quadruplex (G4) DNA structure and a cis-acting sRNA (G4-sRNA) are located upstream of the pilE gene and both are required for pilin antigenic variation (Av). We show that the reduced sRNA transcription lowers pilin Av frequencies. Extended transcriptional elongation is not required for Av, since limiting the transcript to 32 nt allows for normal Av frequencies. Using chromatin immunoprecipitation (ChIP) assays, we show that cellular G4s are less abundant when sRNA transcription is lower. In addition, using ChIP, we demonstrate that the G4-sRNA forms a stable RNA:DNA hybrid (R-loop) with its template strand. However, modulating R-loop levels by controlling RNase HI expression does not alter G4 abundance quantified through ChIP. Since pilin Av frequencies were not altered when modulating R-loop levels by controlling RNase HI expression, we conclude that transcription of the sRNA is necessary, but stable R-loops are not required to promote pilin Av.
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Affiliation(s)
- Lauren L Prister
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Egon A Ozer
- Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Laty A Cahoon
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Hank S Seifert
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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