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Singh RP, Niharika J, Kondepudi KK, Bishnoi M, Tingirikari JMR. Recent understanding of human milk oligosaccharides in establishing infant gut microbiome and roles in immune system. Food Res Int 2022; 151:110884. [PMID: 34980411 DOI: 10.1016/j.foodres.2021.110884] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 11/19/2021] [Accepted: 12/06/2021] [Indexed: 12/16/2022]
Abstract
Human milk oligosaccharides (HMOs) are complex sugars with distinctive structural diversity present in breast milk. HMOs have various functional roles to play in infant development starting from establishing the gut microbiome and immune system to take it up to the mature phase. It has been a major energy source for human gut microbes that confer positive benefits on infant health by directly interacting through intestinal cells and generating short-chain fatty acids. It has recently become evident that each species of Bifidobacterium and other genera which are resident of the infant gut employ distinct molecular mechanisms to capture and digest diverse structural HMOs to avoid competition among themselves and successfully maintain gut homeostasis. HMOs also directly modulate gut immune responses and can decoy receptors of pathogenic bacteria and viruses, inhibiting their binding on intestinal cells, thus preventing the emergence of a disease. This review provides a critical understanding of how different gut bacteria capture and utilize selective sugars from the HMO pool and how different structural HMOs protect infants from infectious diseases.
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Affiliation(s)
- Ravindra Pal Singh
- Laboratory of Gut Glycobiology, Food and Nutritional Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), SAS Nagar, Punjab 140306, India.
| | - Jayashree Niharika
- Laboratory of Gut Glycobiology, Food and Nutritional Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), SAS Nagar, Punjab 140306, India
| | - Kanthi Kiran Kondepudi
- Healthy Gut Research Group, Food and Nutritional Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), SAS Nagar, Punjab 140306, India
| | - Mahendra Bishnoi
- Healthy Gut Research Group, Food and Nutritional Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), SAS Nagar, Punjab 140306, India
| | - Jagan Mohan Rao Tingirikari
- Department of Biotechnology, National Institute of Technology Andhra Pradesh, Tadepalligudem, Andhra Pradesh 534101, India
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2
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Hulbah M, Croxen MA, Tyrrell GJ. Phenotypic changes in group B streptococci grown in the presence of the polyols, erythritol, sorbitol and mannitol. BMC Microbiol 2021; 21:145. [PMID: 33985431 PMCID: PMC8117501 DOI: 10.1186/s12866-021-02208-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 04/29/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Group B streptococci (GBS) are important neonatal bacterial pathogens that can cause severe invasive disease in the newborn. It is thought that in many cases of invasive neonatal GBS disease, the bacteria ascend the vagina into the uterus and infect the amniotic fluid surrounding the fetus. Important constituents of this environment include the polyols or sugar alcohols of which erythritol, sorbitol and mannitol are examples. The aim of our study was to investigate the effect of polyols on GBS grown in media containing these sugar alcohols. RESULTS GBS incubated in varying concentrations of polyols (erythritol, sorbitol or mannitol) did not display any significant enhancement or inhibition of bacterial growth. However, growth of GBS in the presence of erythritol significantly increased the surface expression of GBS-PGK (a plasminogen binding protein) 1.25 to 1.5-fold depending on the erythritol concentration and significantly enhanced the survival in human blood 3X to 18X depending on the concentration of polyol used. Interestingly, GBS grown in 1% erythritol significantly increased invasion by the bacteria of HeLa cells (epithelial cell line) (150% vs 100%) however, at higher concentrations (2% or 4% of polyol) the number of CFUs was significantly reduced (55-75% vs 100%) suggesting higher concentrations of polyols may inhibit invasion. Erythritol also increased GBS hemolytic activity as well as enhancing biofilm formation 1.4X to 3.3X depending on the concentration of polyol used. CONCLUSIONS GBS grown in the presence of polyols alters the bacteria's phenotype resulting in changes associated with GBS virulence. This effect was greatest for the polyol erythritol.
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Affiliation(s)
- Maram Hulbah
- Division of Diagnostic and Applied Microbiology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Matthew A Croxen
- Division of Diagnostic and Applied Microbiology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
- Alberta Precision Laboratories-Public Health, Edmonton, Alberta, T6G 2J2, Canada
| | - Gregory J Tyrrell
- Division of Diagnostic and Applied Microbiology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada.
- Alberta Precision Laboratories-Public Health, Edmonton, Alberta, T6G 2J2, Canada.
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Grech A, Collins CE, Holmes A, Lal R, Duncanson K, Taylor R, Gordon A. Maternal exposures and the infant gut microbiome: a systematic review with meta-analysis. Gut Microbes 2021; 13:1-30. [PMID: 33978558 PMCID: PMC8276657 DOI: 10.1080/19490976.2021.1897210] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/12/2021] [Accepted: 02/22/2021] [Indexed: 02/04/2023] Open
Abstract
Early life, including the establishment of the intestinal microbiome, represents a critical window of growth and development. Postnatal factors affecting the microbiome, including mode of delivery, feeding type, and antibiotic exposure have been widely investigated, but questions remain regarding the influence of exposures in utero on infant gut microbiome assembly. This systematic review aimed to synthesize evidence on exposures before birth, which affect the early intestinal microbiome. Five databases were searched in August 2019 for studies exploring pre-pregnancy or pregnancy 'exposure' data in relation to the infant microbiome. Of 1,441 publications identified, 76 were included. Factors reported influencing microbiome composition and diversity included maternal antibiotic and probiotic uses, dietary intake, pre-pregnancy body mass index (BMI), gestational weight gain (GWG), diabetes, mood, and others. Eleven studies contributed to three meta-analyses quantifying associations between maternal intrapartum antibiotic exposure (IAP), BMI and GWG, and infant microbiome alpha diversity (Shannon Index). IAP, maternal overweight/obesity and excessive GWG were all associated with reduced diversity. Most studies were observational, few included early recruitment or longitudinal follow-up, and the timing, frequency, and methodologies related to stool sampling and analysis were variable. Standardization and collaboration are imperative to enhance understanding in this complex and rapidly evolving area.
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Affiliation(s)
- Allison Grech
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales(NSW), Australia
- Charles Perkins Centre, University of Sydney, Camperdown, NSW, Australia
| | - Clare E Collins
- School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
- Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, NSW, Australia
| | - Andrew Holmes
- Charles Perkins Centre, University of Sydney, Camperdown, NSW, Australia
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Camperdown, NSW, Australia
| | - Ravin Lal
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales(NSW), Australia
- Charles Perkins Centre, University of Sydney, Camperdown, NSW, Australia
| | - Kerith Duncanson
- School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Rachael Taylor
- School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
- Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, NSW, Australia
| | - Adrienne Gordon
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales(NSW), Australia
- Charles Perkins Centre, University of Sydney, Camperdown, NSW, Australia
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Ono E, Uede T. Implication of Soluble Forms of Cell Adhesion Molecules in Infectious Disease and Tumor: Insights from Transgenic Animal Models. Int J Mol Sci 2018; 19:ijms19010239. [PMID: 29342882 PMCID: PMC5796187 DOI: 10.3390/ijms19010239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 12/26/2022] Open
Abstract
Cell adhesion molecules (CAMs) are surface ligands, usually glycoproteins, which mediate cell-to-cell adhesion. They play a critical role in maintaining tissue integrity and mediating migration of cells, and some of them also act as viral receptors. It has been known that soluble forms of the viral receptors bind to the surface glycoproteins of the viruses and neutralize them, resulting in inhibition of the viral entry into cells. Nectin-1 is one of important CAMs belonging to immunoglobulin superfamily and herpesvirus entry mediator (HVEM) is a member of the tumor necrosis factor (TNF) receptor family. Both CAMs also act as alphaherpesvirus receptor. Transgenic mice expressing the soluble form of nectin-1 or HVEM showed almost complete resistance against the alphaherpesviruses. As another CAM, sialic acid-binding immunoglobulin-like lectins (Siglecs) that recognize sialic acids are also known as an immunoglobulin superfamily member. Siglecs play an important role in the regulation of immune cell functions in infectious diseases, inflammation, neurodegeneration, autoimmune diseases and cancer. Siglec-9 is one of Siglecs and capsular polysaccharide (CPS) of group B Streptococcus (GBS) binds to Siglec-9 on neutrophils, leading to suppress host immune response and provide a survival advantage to the pathogen. In addition, Siglec-9 also binds to tumor-produced mucins such as MUC1 to lead negative immunomodulation. Transgenic mice expressing the soluble form of Siglec-9 showed significant resistance against GBS infection and remarkable suppression of MUC1 expressing tumor proliferation. This review describes recent developments in the understanding of the potency of soluble forms of CAMs in the transgenic mice and discusses potential therapeutic interventions that may alter the outcomes of certain diseases.
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Affiliation(s)
- Etsuro Ono
- Department of Biomedicine, Center of Biomedical Research, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
| | - Toshimitsu Uede
- Division of Molecular Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan.
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Olsen P, Williamson M, Traynor V, Georgiou C. The impact of oral probiotics on vaginal Group B Streptococcal colonisation rates in pregnant women: A pilot randomised control study. Women Birth 2017; 31:31-37. [PMID: 28668229 DOI: 10.1016/j.wombi.2017.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 05/11/2017] [Accepted: 06/06/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE To perform a pilot project to determine if this research design was appropriate to explore potential causal relationships between oral probiotic use and vaginal Group B Streptococcal (GBS) colonisation rates in pregnant women. METHOD Thirty-four GBS-positive women at 36 weeks pregnant were recruited. The participants were randomly allocated to the control group, who received standard antenatal care, or to the intervention group, who received standard antenatal care and a daily oral dose of probiotics for three weeks or until they gave birth. A vaginal GBS swab was collected three weeks post consent or during labour. FINDINGS No significant difference was found in vaginal GBS rates between the control and intervention groups. Only seven of 21 women in the intervention group completed the entire 21days of probiotics. A subgroup analysis, including only those who had completed 14days or more of probiotics (n=16), also showed no significant difference in vaginal GBS when compared to the control. The findings did show significantly more vaginal commensals in the probiotics group (p=0.048). DISCUSSION Five possible reasons for the lack of significant results are: the length of the intervention was too short; the dosage of the probiotics was too low; the wrong strains of probiotics were used; the sample size was inadequate; or oral probiotics are ineffective in impacting vaginal GBS. IMPLICATIONS The finding of a significant increase of vaginal commensals in women who completed 14days or more of probiotics supports the potential of probiotics to impact vaginal GBS in pregnancy.
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Affiliation(s)
- Paula Olsen
- School of Nursing, University of Wollongong, Wollongong, NSW 2522, Australia; Maternity Department, The Sutherland Hospital, Caringbah, NSW 2229, Australia.
| | - Moira Williamson
- School of Nursing, University of Wollongong, Wollongong, NSW 2522, Australia; School of Nursing and Midwifery, CQUniversity, Noosaville, QLD 4566, Australia
| | - Victoria Traynor
- School of Nursing, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Chris Georgiou
- Eastern Health, Box Hill, Victoria, Australia; Monash University, Eastern Health Clinical School, Faculty of Medicine, Nursing and Health Sciences, Clayton, Victoria, Australia; Graduate School of Medicine, Faculty of Science, Medicine and Applied Health, University of Wollongong, Illawarra, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Illawarra, NSW, Australia
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Lin AE, Autran CA, Szyszka A, Escajadillo T, Huang M, Godula K, Prudden AR, Boons GJ, Lewis AL, Doran KS, Nizet V, Bode L. Human milk oligosaccharides inhibit growth of group B Streptococcus. J Biol Chem 2017; 292:11243-11249. [PMID: 28416607 DOI: 10.1074/jbc.m117.789974] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Indexed: 11/06/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of invasive bacterial infections in newborns, typically acquired vertically during childbirth secondary to maternal vaginal colonization. Human milk oligosaccharides (HMOs) have important nutritional and biological activities that guide the development of the immune system of the infant and shape the composition of normal gut microbiota. In this manner, HMOs help protect against pathogen colonization and reduce the risk of infection. In the course of our studies of HMO-microbial interactions, we unexpectedly uncovered a novel HMO property to directly inhibit the growth of GBS independent of host immunity. By separating different HMO fractions through multidimensional chromatography, we found the bacteriostatic activity to be confined to specific non-sialylated HMOs and synergistic with a number of conventional antibiotic agents. Phenotypic screening of a GBS transposon insertion library identified a mutation within a GBS-specific gene encoding a putative glycosyltransferase that confers resistance to HMOs, suggesting that HMOs may function as an alternative substrate to modify a GBS component in a manner that impairs growth kinetics. Our study uncovers a unique antibacterial role for HMOs against a leading neonatal pathogen and expands the potential therapeutic utility of these versatile molecules.
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Affiliation(s)
- Ann E Lin
- From the Divisions of Host-Microbe Systems and Therapeutics
| | - Chloe A Autran
- Neonatology, and.,Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics
| | - Alexandra Szyszka
- Neonatology, and.,Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics
| | | | - Mia Huang
- Department of Chemistry and Biochemistry
| | | | - Anthony R Prudden
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Geert-Jan Boons
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Amanda L Lewis
- the Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, and
| | - Kelly S Doran
- From the Divisions of Host-Microbe Systems and Therapeutics.,the Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California 92182
| | - Victor Nizet
- From the Divisions of Host-Microbe Systems and Therapeutics.,Skaggs School of Pharmacy and Pharmaceutical Sciences, and.,Rady Children's Hospital, San Diego, California 92123
| | - Lars Bode
- Neonatology, and .,Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics.,Rady Children's Hospital, San Diego, California 92123.,Larsson-Rosenquist Foundation Mother-Milk-Infant Center of Research Excellence, University of California, San Diego, La Jolla, California 92093
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7
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A soluble form of Siglec-9 provides a resistance against Group B Streptococcus (GBS) infection in transgenic mice. Microb Pathog 2016; 99:106-110. [DOI: 10.1016/j.micpath.2016.08.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/01/2016] [Accepted: 08/09/2016] [Indexed: 11/18/2022]
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Crespo-Ortiz MDP, Castañeda-Ramirez CR, Recalde-Bolaños M, Vélez-Londoño JD. Emerging trends in invasive and noninvasive isolates of Streptococcus agalactiae in a Latin American hospital: a 17-year study. BMC Infect Dis 2014; 14:428. [PMID: 25086463 PMCID: PMC4131052 DOI: 10.1186/1471-2334-14-428] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 07/22/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Streptococcus agalactiae or group B Streptococcus (GBS) has been recognized as a lethal pathogen in neonates worldwide. S. agalactiae infections also severely affect pregnant women and immunosuppressed adults with substantial attributable morbidity and mortality. However, in Latin America, studies on the epidemiology and behaviour of S. agalactiae infections remain limited. METHODS To better understand the behaviour of S. agalactiae infections in our region, we conducted a retrospective study to phenotypically describe S. agalactiae isolates collected in one of the largest hospitals in Colombia at two time periods: 1994-2001 and 2004-2012. The isolates were identified by biochemical analysis and tested for antimicrobial susceptibility. RESULTS In 1994-2001 a total of 201 S. agalactiae isolates were found in urine 38.3%, vaginal exudates 27.8%, soft tissue 12.9%, and blood 8.5%. Susceptibility to ampicillin or penicillin was 94% whereas resistance to erythromycin and clindamycin were 2.8% and 5.2% respectively. In total 46 culture-positive cases of invasive infections were reported, 11 (24%) in neonates and 35 (76%) in adults. In 2004-2012 a total of 671 isolates were found in urine 47.8%, vaginal exudates 32.6%, soft tissue 2.7% and blood 9%. Susceptibility rates to ampicillin and penicillin were 98% whereas resistance to erythromycin and clindamycin were 12.5% and 9.4%. A total of 95 severe infections were reported: 12 (12.6%) were in neonates, 5 (5.3%) in children and 78 (82.1%) in adults. Over the 17-year study period the averaged prevalence of invasive S. agalactiae isolates was 17.4%. The estimated incidence for neonatal infections was 1.34 per 1000 livebirths (0.99 × 1000 livebirths for early- onset disease and 0.35 × 1000 livebirths for late- onset disease) whereas for non-pregnant adults the estimated incidence was 0.75 × 1000 admissions. CONCLUSIONS A remarkable increase in bloodstream infections in immunosuppressed adults and a shift to early neonatal S. agalactiae infections were seen over time. We also found an increase in S. agalactiae resistance to erythromycin and clindamycin during the study period, and the emergence of penicillin-nonsusceptible isolates. Our findings are consistent with the global trends described elsewhere, reinforcing the need for S. agalactiae control measures in our region.
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Affiliation(s)
- Maria del Pilar Crespo-Ortiz
- />Department of Biomedical Sciences, Santiago de Cali University, Cali, Colombia
- />Department of Microbiology, University of Valle, Cali, Colombia
| | - Claudia Rocio Castañeda-Ramirez
- />Microbiology and Infectious Diseases Division, Foundation Valle del Lili Hospital, Cali, Colombia
- />Bacteriology School, University of Valle, Cali, Colombia
| | - Monica Recalde-Bolaños
- />Microbiology and Infectious Diseases Division, Foundation Valle del Lili Hospital, Cali, Colombia
| | - Juan Diego Vélez-Londoño
- />Microbiology and Infectious Diseases Division, Foundation Valle del Lili Hospital, Cali, Colombia
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Abstract
Siglecs are mammalian sialic acid (Sia) recognizing immunoglobulin-like receptors expressed across the major leukocyte lineages, and function to recognize ubiquitous Sia epitopes on cell surface glycoconjugates and regulate immunological and inflammatory activities of these cells. A large subset referred to as CD33-related Siglecs are inhibitory receptors that limit leukocyte activation, and recent research has shown that the pathogen group B Streptococcus (GBS) binds to these Siglecs in Sia- and protein-dependent fashion to downregulate leukocyte bactericidal capacity. Conversely, sialoadhesin is a macrophage phagocytic receptor that engages GBS and other sialylated pathogens to promote effective phagocytosis and antigen presentation for the adaptive immune response. A variety of other important Siglec interactions with bacterial, viral and protozoan pathogens are beginning to be recognized. Siglec genes and binding specificities are rapidly evolving among primates, with key extant polymorphisms in human populations that may influence susceptibility to infection-associated disorders including chronic obstructive pulmonary disease and premature birth. This review summarizes current understanding of interactions between pathogens and Siglecs, a field of investigation that is likely to continue expanding in scope and medical importance.
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Affiliation(s)
- Yung-Chi Chang
- Glycobiology Research and Training Center Department of Pediatrics
| | - Victor Nizet
- Glycobiology Research and Training Center Department of Pediatrics Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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Chang YC, Olson J, Beasley FC, Tung C, Zhang J, Crocker PR, Varki A, Nizet V. Group B Streptococcus engages an inhibitory Siglec through sialic acid mimicry to blunt innate immune and inflammatory responses in vivo. PLoS Pathog 2014; 10:e1003846. [PMID: 24391502 PMCID: PMC3879367 DOI: 10.1371/journal.ppat.1003846] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 11/06/2013] [Indexed: 12/15/2022] Open
Abstract
Group B Streptococcus (GBS) is a common agent of bacterial sepsis and meningitis in newborns. The GBS surface capsule contains sialic acids (Sia) that engage Sia-binding immunoglobulin-like lectins (Siglecs) on leukocytes. Here we use mice lacking Siglec-E, an inhibitory Siglec of myelomonocytic cells, to study the significance of GBS Siglec engagement during in vivo infection. We found GBS bound to Siglec-E in a Sia-specific fashion to blunt NF-κB and MAPK activation. As a consequence, Siglec-E-deficient macrophages had enhanced pro-inflammatory cytokine secretion, phagocytosis and bactericidal activity against the pathogen. Following pulmonary or low-dose intravenous GBS challenge, Siglec-E KO mice produced more pro-inflammatory cytokines and exhibited reduced GBS invasion of the central nervous system. In contrast, upon high dose lethal challenges, cytokine storm in Siglec-E KO mice was associated with accelerated mortality. We conclude that GBS Sia mimicry influences host innate immune and inflammatory responses in vivo through engagement of an inhibitory Siglec, with the ultimate outcome of the host response varying depending upon the site, stage and magnitude of infection. The bacterium Group B Streptococcus (GBS) causes serious infections such as meningitis in human newborn babies. The surface of GBS is coated with a capsule made of sugar molecules. Prominent among these is sialic acid (Sia), a human-like sugar that interacts with protein receptors called Siglecs on the surface of our white blood cells. In a test tube, GBS Sia binding to human Siglecs can suppress white blood cell activation, reducing their bacterial killing abilities; however, the significance of this during actual infection was unknown. To answer this question, we studied mice for which a key white blood cell Siglec has been genetically deleted. When infected with GBS, white blood cells from the mutant mice are not shut off by the pathogen's Sia-containing sugar capsule. The white blood cells from the Siglec-deficient mice are better at killing GBS and are able to clear infection more quickly than a normal mouse. However, if the mice are given an overwhelming dose of GBS bacteria, exaggerated white blood activation can trigger shock and more rapid death. These studies show how “molecular mimicry” of sugar molecules in the host can influence a bacterial pathogen's interaction with the immune system and the outcome of infection.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/immunology
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/immunology
- Cytokines/genetics
- Cytokines/immunology
- Humans
- Inflammation/genetics
- Inflammation/immunology
- Inflammation/pathology
- Macrophages/immunology
- Macrophages/pathology
- Mice
- Mice, Knockout
- Molecular Mimicry/immunology
- N-Acetylneuraminic Acid/genetics
- N-Acetylneuraminic Acid/immunology
- Pneumonia, Bacterial/genetics
- Pneumonia, Bacterial/immunology
- Pneumonia, Bacterial/pathology
- Streptococcal Infections/genetics
- Streptococcal Infections/immunology
- Streptococcal Infections/pathology
- Streptococcus agalactiae/immunology
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Affiliation(s)
- Yung-Chi Chang
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Joshua Olson
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Federico C. Beasley
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Christine Tung
- Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Jiquan Zhang
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Paul R. Crocker
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ajit Varki
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California, United States of America
- Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, United States of America
- * E-mail: (AV); (VN)
| | - Victor Nizet
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
- Rady Children's Hospital, San Diego, California, United States of America
- * E-mail: (AV); (VN)
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Penicillin susceptibility and macrolide-lincosamide-streptogramin B resistance in group B Streptococcus isolates from a Canadian hospital. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2012; 23:196-8. [PMID: 24294274 DOI: 10.1155/2012/540127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Intrapartum antibiotic prophylaxis (IAP) is recommended for pregnant women who test positive for group B Streptococcus (GBS) in their genitourinary tract to prevent GBS-induced neonatal sepsis. Penicillin G is used as the primary antibiotic, and clindamycin or erythromycin as the secondary, if allergies exist. Decreased susceptibility to penicillin G has occasionally been reported; however, clindamycin and erythromycin resistance is on the rise and is causing concern over the use of clindamycin and erythromycin IAP. METHODS Antibiotic resistance was characterized phenotypically using a D-Test for erythromycin and clindamycin, while an E-Test (E-strip) was used for penicillin G. GBS was isolated from vaginal-rectal swabs and serologically confirmed using Prolex (Pro-Lab Diagnostics, Canada) streptococcal grouping reagents. Susceptibility testing of isolates was performed according to the Clinical Laboratory Standards Institute guidelines. RESULTS All 158 isolates were penicillin G sensitive. Inducible macrolide-lincosamide-streptogramin B (MLSB) resistance was observed in 13.9% of isolates. Constitutive MLSB resistance was observed in 12.7% of isolates. M phenotype resistance was observed in 6.3% of isolates. In total, erythromycin resistance was present in 32.9% of the GBS isolates, while clindamycin resistance was present in 26.6%. DISCUSSION The sampled GBS population showed no sign of reduced penicillin susceptibility, with all being well under susceptible minimum inhibitory concentration values. These data are congruent with the large body of evidence showing that penicillin G remains the most reliable clinical antibiotic for IAP. Clindamycin and erythromycin resistance was higher than expected, contributing to a growing body of evidence that suggests the re-evaluation of clindamycin and erythromycin IAP is warranted.
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Madureira P, Andrade EB, Gama B, Oliveira L, Moreira S, Ribeiro A, Correia-Neves M, Trieu-Cuot P, Vilanova M, Ferreira P. Inhibition of IL-10 production by maternal antibodies against Group B Streptococcus GAPDH confers immunity to offspring by favoring neutrophil recruitment. PLoS Pathog 2011; 7:e1002363. [PMID: 22114550 PMCID: PMC3219712 DOI: 10.1371/journal.ppat.1002363] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 09/22/2011] [Indexed: 11/19/2022] Open
Abstract
Group B Streptococcus (GBS) is the leading cause of neonatal pneumonia, septicemia, and meningitis. We have previously shown that in adult mice GBS glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an extracellular virulence factor that induces production of the immunosuppressive cytokine interleukin-10 (IL-10) by the host early upon bacterial infection. Here, we investigate whether immunity to neonatal GBS infection could be achieved through maternal vaccination against bacterial GAPDH. Female BALB/c mice were immunized with rGAPDH and the progeny was infected with a lethal inoculum of GBS strains. Neonatal mice born from mothers immunized with rGAPDH were protected against infection with GBS strains, including the ST-17 highly virulent clone. A similar protective effect was observed in newborns passively immunized with anti-rGAPDH IgG antibodies, or F(ab')2 fragments, indicating that protection achieved with rGAPDH vaccination is independent of opsonophagocytic killing of bacteria. Protection against lethal GBS infection through rGAPDH maternal vaccination was due to neutralization of IL-10 production soon after infection. Consequently, IL-10 deficient (IL-10−/−) mice pups were as resistant to GBS infection as pups born from vaccinated mothers. We observed that protection was correlated with increased neutrophil trafficking to infected organs. Thus, anti-rGAPDH or anti-IL-10R treatment of mice pups before GBS infection resulted in increased neutrophil numbers and lower bacterial load in infected organs, as compared to newborn mice treated with the respective control antibodies. We showed that mothers immunized with rGAPDH produce neutralizing antibodies that are sufficient to decrease IL-10 production and induce neutrophil recruitment into infected tissues in newborn mice. These results uncover a novel mechanism for GBS virulence in a neonatal host that could be neutralized by vaccination or immunotherapy. As GBS GAPDH is a structurally conserved enzyme that is metabolically essential for bacterial growth in media containing glucose as the sole carbon source (i.e., the blood), this protein constitutes a powerful candidate for the development of a human vaccine against this pathogen. Streptococcus agalactiae (Group B streptococcus, GBS) is the leading infectious cause of morbidity and mortality among neonates. However, there is still no satisfactory explanation of why neonates are so susceptible to GBS infections. Intrapartum antibiotic prophylaxis (IAP) was implemented in many countries but led to the emergence of antibiotic-resistant GBS strains. Therefore, maternal vaccination represents an attractive alternative to IAP. Here, we show that the high susceptibility of newborn mice to GBS infections is associated with their propensity to produce elevated amounts of immunosuppressive cytokine IL-10. We also demonstrate that IL-10 impairs neutrophil recruitment into infected organs thus preventing bacterial clearance. We identified extracellular GAPDH as the GBS factor that induces the high IL-10 production detected early upon neonatal infection. We show that maternal vaccination with recombinant GAPDH confers robust protective immunity against lethal infection with a GBS hyper-virulent strain in mice offspring. This protection can also be obtained either by antibody neutralization of GBS GAPDH or by blocking IL-10 binding to its receptor. As GBS GAPDH is an essential protein for bacterial growth, it is present in all GBS strains and thus constitutes an appropriate target antigen for a global effective vaccine against this pathogen.
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Affiliation(s)
- Pedro Madureira
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Porto, Portugal
| | - Elva Bonifácio Andrade
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Porto, Portugal
| | - Bernardo Gama
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Liliana Oliveira
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Porto, Portugal
| | - Susana Moreira
- IBB, Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Adília Ribeiro
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Porto, Portugal
| | - Margarida Correia-Neves
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
- ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrick Trieu-Cuot
- Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram-Positif, CNRS URA 2172, Paris, France
| | - Manuel Vilanova
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Porto, Portugal
| | - Paula Ferreira
- ICBAS – Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Porto, Portugal
- * E-mail:
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Abstract
Group B streptococcus (GBS) is a major cause of severe bacterial infection in newborns. Early neonatal GBS infection can be prevented by identifying high-risk pregnancies and administering intrapartum antibiotics. In the USA, a screening strategy has been introduced resulting in a reduction in early-onset GBS infection, but no decrease in late-onset neonatal GBS disease has been noted. In many European countries, a risk-based strategy is recommended. Vaccination may, in the future, be an alternative in preventing GBS infection in newborns.
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Affiliation(s)
- Karin Pettersson
- Department of Obstetrics and Gynaecology, Karolinska University Hospital, Huddinge, 141 86 Stockholm, Sweden.
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