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Kasai Y, Komatsu M, Toyama Y, Nakano S, Hisata K, Yamada M, Shimizu T. Effect of probiotics on mother-to-neonate vertical transmission of group B streptococci: A prospective open-label randomized study. Pediatr Neonatol 2024; 65:145-151. [PMID: 37684161 DOI: 10.1016/j.pedneo.2023.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 06/16/2023] [Accepted: 07/18/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND Group B Streptococci (GBS) are common vaginal bacteria found in 20-30% of pregnant women and a significant cause of invasive infections in newborns. Recently, attention has been focused on the efficacy of probiotics during the perinatal period. However, the effect of probiotic intake on the mother-to-child transmission (MTCT) of GBS remains unknown. METHODS Pregnant women with positive GBS results from vaginal and rectal swab cultures at 35-37 weeks of gestation were randomly assigned to the probiotic group or the control group in an open-label manner at the Department of Obstetrics and Gynecology, San-ikukai Hospital, Tokyo, Japan. The probiotic group received Lactobacillus reuteri during antenatal checkups from 35 to 37-week gestation to 1 month after delivery. Rectal swabs were obtained from the newborns at 5 days and at 1 month of age. Whole-genome sequencing was performed to test for GBS strains in the mother, whose newborn carried GBS at the 1-month checkup. Multi-locus sequence typing and single nucleotide polymorphism analyses were performed to identify MTCT. RESULTS Overall, 67 mother-infant pairs were included, with 31 in the probiotic group and 36 in the control group. The positivity rate of GBS in newborns at 1 month of age was 10% (n = 3) in the probiotic group and 28% (n = 10) in the control group. In newborns carrying GBS at 1 month of age, genetic analysis revealed that the MTCT rate was 6% in the probiotic group and 22% in the control group, although the difference was not statistically significant (p = 0.0927). CONCLUSION No statistically significant difference was found; however, the consumption of L. reuteri by women with GBS-positive pregnancies may inhibit the MTCT of GBS.
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Affiliation(s)
- Yuriha Kasai
- Department of Pediatric and Adolescent Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8431, Japan
| | - Mitsutaka Komatsu
- Department of Pediatrics, San-Ikukai Hospital, 3-20-2 Taihei, Sumida-ku, Tokyo, 130-0012, Japan.
| | - Yudai Toyama
- Department of Pediatrics, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima-ku, Tokyo, 177-8521, Japan
| | - Saki Nakano
- Department of Pediatrics, Tokyo Rinkai Hospital, 1-4-2 Rinkai-cho, Edogawa-ku, Tokyo, 134-0086, Japan
| | - Ken Hisata
- Department of Pediatrics, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8431, Japan
| | - Mie Yamada
- Department of Obstetrics and Gynecology, San-Ikukai Hospital, 3-20-2 Taihei, Sumida-ku, Tokyo, 130-0012, Japan
| | - Toshiaki Shimizu
- Department of Pediatric and Adolescent Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8431, Japan
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Plainvert C, Rosinski-Chupin I, Weckel A, Lambert C, Touak G, Sauvage E, Poyart C, Glaser P, Fouet A. A Novel CovS Variant Harbored by a Colonization Strain Reduces Streptococcus pyogenes Virulence. J Bacteriol 2023; 205:e0003923. [PMID: 36920220 PMCID: PMC10127592 DOI: 10.1128/jb.00039-23] [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: 02/02/2023] [Accepted: 02/16/2023] [Indexed: 03/16/2023] Open
Abstract
Streptococcus pyogenes, also known as group A Streptococcus, causes a wide variety of diseases ranging from mild noninvasive to severe invasive infections. To identify possible causes of colonization-to-invasive switches, we determined the genomic sequences of 10 isolates from five pairs each composed of an invasive strain and a carriage strain originating from five infectious clusters. Among them, one pair displayed a single-nucleotide difference in covS, encoding the sensor histidine kinase of the two-component CovRS system that controls the expression of 15% of the genome. In contrast to previously described cases where the invasive strains harbor nonfunctional CovS proteins, the carriage strain possessed the mutation covST115C, leading to the replacement of the tyrosine at position 39 by a histidine. The CovSY39H mutation affected the expression of the genes from the CovR regulon in a unique fashion. Genes usually overexpressed in covS mutant strains were underexpressed and vice versa. Furthermore, the covS mutant strain barely responded to the addition of the CovS-signaling compounds Mg2+ and LL-37. The variations in the accumulation of two virulence factors paralleled the transcription modifications. In addition, the covST115C mutant strain showed less survival than its wild-type counterpart in murine macrophages. Finally, in two murine models of infection, the covS mutant strain was less virulent than the wild-type strain. Our study suggests that the CovSY39H protein compromises CovS phosphatase activity and that this yields a noninvasive strain. IMPORTANCE Streptococcus pyogenes, also known as group A Streptococcus, causes a wide variety of diseases, leading to 517,000 deaths yearly. The two-component CovRS system, which responds to MgCl2 and the antimicrobial peptide LL-37, controls the expression of 15% of the genome. Invasive strains may harbor nonfunctional CovS sensor proteins that lead to the derepression of most virulence genes. We isolated a colonization strain that harbors a novel covS mutation. This mutant strain harbored a transcriptome profile opposite that of other covS mutant strains, barely responded to environmental signals, and was less virulent than the wild-type strain. This supports the importance of the derepression of the expression of most virulence genes, via mutations that impact the phosphorylation of the regulator CovR, for favoring S. pyogenes invasive infections.
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Affiliation(s)
- Céline Plainvert
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
| | - Isabelle Rosinski-Chupin
- Institut Pasteur, Ecologie et Evolution de la Résistance aux Antibiotiques, UMR3525, Paris, France
| | - Antonin Weckel
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Clara Lambert
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Gérald Touak
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
| | - Elisabeth Sauvage
- Institut Pasteur, Ecologie et Evolution de la Résistance aux Antibiotiques, UMR3525, Paris, France
| | - Claire Poyart
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
| | - Philippe Glaser
- Institut Pasteur, Ecologie et Evolution de la Résistance aux Antibiotiques, UMR3525, Paris, France
| | - Agnès Fouet
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
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3
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Chaguza C, Jamrozy D, Bijlsma MW, Kuijpers TW, van de Beek D, van der Ende A, Bentley SD. Population genomics of Group B Streptococcus reveals the genetics of neonatal disease onset and meningeal invasion. Nat Commun 2022; 13:4215. [PMID: 35864107 PMCID: PMC9304382 DOI: 10.1038/s41467-022-31858-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/06/2022] [Indexed: 11/09/2022] Open
Abstract
Group B Streptococcus (GBS), or Streptococcus agalactiae, is a pathogen that causes preterm births, stillbirths, and acute invasive neonatal disease burden and mortality. Here, we investigate bacterial genetic signatures associated with disease onset time and meningeal tissue infection in acute invasive neonatal GBS disease. We carry out a genome-wide association study (GWAS) of 1,338 GBS isolates from newborns with acute invasive disease; the isolates had been collected annually, for 30 years, through a national bacterial surveillance program in the Netherlands. After controlling for the population structure, we identify genetic variation within noncoding and coding regions, particularly the capsule biosynthesis locus, statistically associated with neonatal GBS disease onset time and meningeal invasion. Our findings highlight the impact of integrating microbial population genomics and clinical pathogen surveillance, and demonstrate the effect of GBS genetics on disease pathogenesis in neonates and infants.
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Affiliation(s)
- Chrispin Chaguza
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT, USA.
| | - Dorota Jamrozy
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Merijn W Bijlsma
- Department of Neurology, Amsterdam Neuroscience, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Taco W Kuijpers
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Paediatric Haematology, Immunology and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Diederik van de Beek
- Department of Neurology, Amsterdam Neuroscience, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Arie van der Ende
- Department of Medical Microbiology, Amsterdam Infection and Immunity, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
- Netherlands Reference Laboratory for Bacterial Meningitis, Center of Infection and Immunity Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands.
| | - Stephen D Bentley
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.
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Berardi A, Trevisani V, Di Caprio A, Bua J, China M, Perrone B, Pagano R, Lucaccioni L, Fanaro S, Iughetti L, Lugli L, Creti R. Understanding Factors in Group B Streptococcus Late-Onset Disease. Infect Drug Resist 2021; 14:3207-3218. [PMID: 34429620 PMCID: PMC8380284 DOI: 10.2147/idr.s291511] [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: 05/26/2021] [Accepted: 07/14/2021] [Indexed: 12/22/2022] Open
Abstract
Group B streptococcus (GBS) infection remains a leading cause of sepsis, pneumonia, and meningitis in infants. Rates of GBS early onset disease have declined following the widcespread use of intrapartum antibiotic prophylaxis; hence, late-onset infections (LOGBS) are currently a common presentation of neonatal GBS dicsease. The pathogenesis, mode of transmission, and risk factors associated with LOGBS are unclear, which interfere with effective prevention efforts. GBS may be transmitted from the mother to the infant at the time of delivery or during the postpartum period via contaminated breast milk, or as nosocomial or community-acquired infection. Maternal GBS colonization, prematurity, young maternal age, HIV exposure, and ethnicity (Black) are identified as risk factors for LOGBS disease; however, further studies are necessary to confirm additional risk factors, if any, for the implementation of effective prevention strategies. This narrative review discusses current and previous studies that have reported LOGBS. Few well-designed studies have described this condition; therefore, reliable assessment of maternal GBS colonization, breastfeeding, and twin delivery as risk factors for LOGBS remains limited.
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Affiliation(s)
- Alberto Berardi
- Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | - Viola Trevisani
- Scuola di Specializzazione in Pediatria, Università di Modena & Reggio Emilia, Modena, Italy
| | - Antonella Di Caprio
- Scuola di Specializzazione in Pediatria, Università di Modena & Reggio Emilia, Modena, Italy
| | - Jenny Bua
- Terapia Intensiva Neonatale, IRCCS Azienda Ospedaliero Universitaria "Burlo Garofalo", Trieste, Italy
| | | | - Barbara Perrone
- Terapia Intensiva Neonatale, Azienda Ospedaliero Universitaria Ospedali Riuniti, Ancona, Italy
| | - Rossella Pagano
- Unità Operativa di Pediatria, Civile Sassuolo, Sassuolo, Italy
| | - Laura Lucaccioni
- Unità Operativa di Pediatria, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | - Silvia Fanaro
- Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria S. Anna, Ferrara, Italy
| | - Lorenzo Iughetti
- Scuola di Specializzazione in Pediatria, Università di Modena & Reggio Emilia, Modena, Italy.,Unità Operativa di Pediatria, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | - Licia Lugli
- Terapia Intensiva Neonatale, Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy
| | - Roberta Creti
- Reparto di Antibiotico Resistenza e Patogeni Speciali (AR-PS), Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
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Evolution of VIM-1-Producing Klebsiella pneumoniae Isolates from a Hospital Outbreak Reveals the Genetic Bases of the Loss of the Urease-Positive Identification Character. mSystems 2021; 6:e0024421. [PMID: 34060914 PMCID: PMC8269217 DOI: 10.1128/msystems.00244-21] [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] [Indexed: 11/20/2022] Open
Abstract
Outbreaks of carbapenemase-producing Klebsiella pneumoniae (CPKp) represent a major threat for hospitals. We molecularly characterized the first outbreak of VIM-1-producing K. pneumoniae in Spain, which raised fears about the spread of this strain or of the plasmid carrying blaVIM-1. Through in-depth genomic analysis of 18 isolates recovered between October 2005 and September 2007, we show that 17 ST39 isolates were clonal, whereas the last isolate had acquired the VIM-1 plasmid from the epidemic clone. The index isolate carried 31 antibiotic resistance genes (ARGs) and was resistant to almost all antibiotics tested. Later isolates further gained mutations in efflux pump regulators ramR and opxR, deletion of mgrB (colistin resistance), and frameshift mutations in ompK36 (β-lactam resistance) likely selected by antibiotic usage. Comparison with publicly available genome sequences and literature review revealed no sign of dissemination of this CPKp strain. However, the VIM-1 plasmid was found in diverse Enterobacterales species, although restricted to Spain. One isolate became urease negative following IS5075 transposition into ureC. Analysis of 9,755 K. pneumoniae genomes showed the same ureC::IS5075 insertion in 14.1% of the isolates and explained why urease activity is a variable identification trait for K. pneumoniae. Transposition into ureC results from the similarity of its 3' end and the terminal inverted repeats of Tn21-like transposons, the targets of IS5075 and related insertion sequences (ISs). As these transposons frequently carry ARGs, this might explain the frequent chromosomal invasion by these ISs and ureC inactivation in multidrug-resistant isolates. IMPORTANCE Evolution of multidrug-resistant bacterial pathogens occurs at multiple scales, in the patient, locally in the hospital, or more globally. Some mutations or gene acquisitions, for instance in response to antibiotic treatment, may be restricted to a single patient due to their high fitness cost. However, some events are more general. By analyzing the evolution of a hospital-acquired multidrug-resistant K. pneumoniae strain producing the carbapenemase VIM-1, we showed a likely environmental source in the hospital and identified mutations contributing to a further decrease in antibiotic susceptibility. By combining the genomic analysis of this outbreak with literature data and genome sequences available in databases, we showed that the VIM-1 plasmid has been acquired by different Enterobacterales but is endemic only in Spain. We also discovered that urease loss in K. pneumoniae results from the specific transposition of an IS element into the ureC gene and was more frequent in fluoroquinolone-resistant isolates and those carrying a carbapenemase gene.
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6
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Systematic review of Group B Streptococcal capsular types, sequence types and surface proteins as potential vaccine candidates. Vaccine 2020; 38:6682-6694. [PMID: 32888741 PMCID: PMC7526974 DOI: 10.1016/j.vaccine.2020.08.052] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 01/31/2023]
Abstract
Most comprehensive review of Group B Streptococcal serotypes through 2018. First systematic review of Group B Streptococcal strain type and protein data. Theoretically candidate vaccines may protect against 93-99% disease-causing strains. More studies on GBS strains in low- and middle-income countries are needed.
Background 21 million pregnant women worldwide (18%) are estimated to carry Group B Streptococcus (GBS), which is a risk for invasive disease in newborns, pregnant women, and stillbirths. Adults ≥ 60 years or with underlying health conditions are also vulnerable to invasive GBS disease. We undertook systematic reviews on GBS organism characteristics including: capsular polysaccharide (serotype), sequence type (multi-locus sequence types (MLST)), and virulence proteins. We synthesised data by at-risk populations, to inform vaccine development. Methods We conducted systematic reviews and meta-analyses to estimate proportions of GBS serotypes for at risk populations: maternal colonisation, invasive disease in pregnant women, stillbirths, infants 0–90 days age, and older adults (≥60 years). We considered regional variation and time trends (2001–2018). For these at-risk population groups, we summarised reported MLST and surface proteins. Results Based on 198 studies (29247isolates), 93–99% of GBS isolates were serotypes Ia, Ib, II, III, IV and V. Regional variation is likely, but data gaps are apparent, even for maternal colonisation which has most data. Serotype III dominates for infant invasive disease (60%) and GBS-associated stillbirths (41%). ST17 accounted for a high proportion of infant invasive disease (41%; 95%CI: 35–47) and was found almost exclusively in serotype III strains, less present in maternal colonisation (9%; 95%CI:6–13),(4%; 95%CI:0–11) infant colonisation, and adult invasive disease (4%, 95%CI:2–6). Percentages of strains with at least one of alp 1, alp2/3, alpha C or Rib surface protein targets were 87% of maternal colonisation, 97% infant colonisation, 93% infant disease and 99% adult invasive disease. At least one of three pilus islands proteins were reported in all strains. Discussion A hexavalent vaccine (serotypes Ia, Ib, II, III, IV and V) might provide comprehensive cover for all at-risk populations. Surveillance of circulating, disease-causing target proteins is useful to inform vaccines not targeting capsular polysaccharide. Addressing data gaps especially by world region and some at-risk populations (notably stillbirths) is fundamental to evidence-based decision-making during vaccine design.
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7
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Armistead B, Quach P, Snyder JM, Santana-Ufret V, Furuta A, Brokaw A, Rajagopal L. Hemolytic Membrane Vesicles of Group B Streptococcus Promote Infection. J Infect Dis 2020; 223:1488-1496. [PMID: 32861213 DOI: 10.1093/infdis/jiaa548] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/25/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Group B streptococci (GBS) are β-hemolytic, Gram-positive bacteria associated with fetal injury, preterm birth, spontaneous abortion, and neonatal infections. A key factor promoting GBS virulence is the β-hemolysin/cytolysin, a pigmented ornithine rhamnolipid (also known as granadaene) associated with the bacterial surface. METHODS A previous study indicated that GBS produce small structures known as membrane vesicles (MVs), which contain virulence-associated proteins. In this study, we show that GBS MVs are pigmented and hemolytic, indicating that granadaene is functionally active in MVs. RESULTS In addition, MVs from hyperhemolytic GBS induced greater cell death of neutrophils, T cells, and B cells compared with MVs from isogenic nonhemolytic GBS, implicating MVs as a potential mechanism for granadaene-mediated virulence. Finally, hemolytic MVs reduced oxidative killing of GBS and aggravated morbidity and mortality of neonatal mice infected with GBS. CONCLUSIONS These studies, taken together, reveal a novel mechanism by which GBS deploy a crucial virulence factor to promote bacterial dissemination and pathogenesis.
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Affiliation(s)
- Blair Armistead
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Verónica Santana-Ufret
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Anna Furuta
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Alyssa Brokaw
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
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8
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Armistead B, Whidbey C, Iyer LM, Herrero-Foncubierta P, Quach P, Haidour A, Aravind L, Cuerva JM, Jaspan HB, Rajagopal L. The cyl Genes Reveal the Biosynthetic and Evolutionary Origins of the Group B Streptococcus Hemolytic Lipid, Granadaene. Front Microbiol 2020; 10:3123. [PMID: 32038561 PMCID: PMC6985545 DOI: 10.3389/fmicb.2019.03123] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 12/24/2019] [Indexed: 01/31/2023] Open
Abstract
Group B Streptococcus (GBS) is a β-hemolytic, Gram-positive bacterium that commonly colonizes the female lower genital tract and is associated with fetal injury, preterm birth, spontaneous abortion, and neonatal infections. A major factor promoting GBS virulence is the β-hemolysin/cytolysin, which is cytotoxic to several host cells. We recently showed that the ornithine rhamnolipid pigment, Granadaene, produced by the gene products of the cyl operon, is hemolytic. Here, we demonstrate that heterologous expression of the GBS cyl operon conferred hemolysis, pigmentation, and cytoxicity to Lactococcus lactis, a model non-hemolytic Gram-positive bacterium. Similarly, pigment purified from L. lactis is hemolytic, cytolytic, and identical in structure to Granadaene extracted from GBS, indicating the cyl operon is sufficient for Granadaene production in a heterologous host. Using a systematic survey of phyletic patterns and contextual associations of the cyl genes, we identify homologs of the cyl operon in physiologically diverse Gram-positive bacteria and propose undescribed functions of cyl gene products. Together, these findings bring greater understanding to the biosynthesis and evolutionary foundations of a key GBS virulence factor and suggest that such potentially toxic lipids may be encoded by other bacteria.
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Affiliation(s)
- Blair Armistead
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Christopher Whidbey
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Lakshminarayan M Iyer
- Computational Biology Branch, National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, United States
| | | | - Phoenicia Quach
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Ali Haidour
- Department of Organic Chemistry, University of Granada, Granada, Spain
| | - L Aravind
- Computational Biology Branch, National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, United States
| | | | - Heather B Jaspan
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States.,Department of Pathology, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle, WA, United States.,Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States
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9
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Gendrin C, Merillat S, Vornhagen J, Coleman M, Armistead B, Ngo L, Aggarwal A, Quach P, Berrigan J, Rajagopal L. Diminished Capsule Exacerbates Virulence, Blood-Brain Barrier Penetration, Intracellular Persistence, and Antibiotic Evasion of Hyperhemolytic Group B Streptococci. J Infect Dis 2019; 217:1128-1138. [PMID: 29301010 DOI: 10.1093/infdis/jix684] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/28/2017] [Indexed: 12/21/2022] Open
Abstract
Group B streptococci (GBS) are encapsulated, β-hemolytic bacteria that are a common cause of infections in human newborns and certain adults. Two factors important for GBS virulence are the sialic acid capsular polysaccharide that promotes immune evasion and the hemolytic pigment that induces host cell cytotoxcity. These virulence factors are often oppositely regulated by the CovR/CovS two-component system. Clinical GBS strains exhibiting hyperhemolysis and low capsule due to pathoadaptive covR/S mutations have been isolated from patients. Given the importance of capsule to GBS virulence, we predicted that a decrease or loss of capsule would attenuate the virulence of covR/S mutants. Surprisingly, hyperhemolytic GBS with low or no capsule exhibit increased virulence, intracellular persistence, and blood-brain barrier penetration, which was independent of a Trojan horse mechanism of barrier penetration. Additionally, intracellular persistence enabled both hemolytic and hyperhemolytic GBS to evade antibiotics routinely used to treat these infections. The finding that diminished capsule expression promotes GBS virulence, intracellular persistence, and antibiotic evasion has important implications for sustained antibiotic therapy and efficacy of capsule-based vaccines.
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Affiliation(s)
- Claire Gendrin
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Sean Merillat
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Jay Vornhagen
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute.,Department of Global Health, University of Washington, Seattle
| | - Michelle Coleman
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Blair Armistead
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute.,Department of Global Health, University of Washington, Seattle
| | - Lisa Ngo
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Anjali Aggarwal
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Phoenicia Quach
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Jacob Berrigan
- Center for Global Infections Disease Research, Seattle Children's Research Institute
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington.,Center for Global Infections Disease Research, Seattle Children's Research Institute.,Department of Global Health, University of Washington, Seattle
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10
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Madrid L, Seale AC, Kohli-Lynch M, Edmond KM, Lawn JE, Heath PT, Madhi SA, Baker CJ, Bartlett L, Cutland C, Gravett MG, Ip M, Le Doare K, Rubens CE, Saha SK, Sobanjo-Ter Meulen A, Vekemans J, Schrag S. Infant Group B Streptococcal Disease Incidence and Serotypes Worldwide: Systematic Review and Meta-analyses. Clin Infect Dis 2018; 65:S160-S172. [PMID: 29117326 PMCID: PMC5850457 DOI: 10.1093/cid/cix656] [Citation(s) in RCA: 262] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background Group B Streptococcus (GBS) remains a leading cause of neonatal sepsis in high-income contexts, despite declines due to intrapartum antibiotic prophylaxis (IAP). Recent evidence suggests higher incidence in Africa, where IAP is rare. We investigated the global incidence of infant invasive GBS disease and the associated serotypes, updating previous estimates. Methods We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus) and sought unpublished data regarding invasive GBS disease in infants aged 0–89 days. We conducted random-effects meta-analyses of incidence, case fatality risk (CFR), and serotype prevalence. Results We identified 135 studies with data on incidence (n = 90), CFR (n = 64), or serotype (n = 45). The pooled incidence of invasive GBS disease in infants was 0.49 per 1000 live births (95% confidence interval [CI], .43–.56), and was highest in Africa (1.12) and lowest in Asia (0.30). Early-onset disease incidence was 0.41 (95% CI, .36–.47); late-onset disease incidence was 0.26 (95% CI, .21–.30). CFR was 8.4% (95% CI, 6.6%–10.2%). Serotype III (61.5%) dominated, with 97% of cases caused by serotypes Ia, Ib, II, III, and V. Conclusions The incidence of infant GBS disease remains high in some regions, particularly Africa. We likely underestimated incidence in some contexts, due to limitations in case ascertainment and specimen collection and processing. Burden in Asia requires further investigation.
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Affiliation(s)
- Lola Madrid
- ISGlobal, Barcelona Centre for International Health Research, Hospital Clinic-University of Barcelona, Spain.,Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom.,Centro de Investigação em Saúde de Manhiça, Mozambique
| | - Anna C Seale
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom.,College of Health and Medical Sciences, Haramaya University, Dire Dawa, Ethiopia
| | - Maya Kohli-Lynch
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom.,Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, United Kingdom
| | | | - Joy E Lawn
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Paul T Heath
- Vaccine Institute, Institute for Infection and Immunity, St George's, University of London and St George's University Hospitals NHS Foundation Trust, United Kingdom
| | - Shabir A Madhi
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, and Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Sciences.,National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Carol J Baker
- Departments of Pediatrics and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Linda Bartlett
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Clare Cutland
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, and Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Sciences
| | - Michael G Gravett
- Global Alliance to Prevent Prematurity and Stillbirth, Seattle, Washington.,Department of Obstetrics and Gynecology, University of Washington, Seattle
| | - Margaret Ip
- Department of Microbiology, Faculty of Medicine, Chinese University of Hong Kong
| | - Kirsty Le Doare
- Vaccine Institute, Institute for Infection and Immunity, St George's, University of London and St George's University Hospitals NHS Foundation Trust, United Kingdom.,Centre for International Child Health, Imperial College London, United Kingdom
| | - Craig E Rubens
- Global Alliance to Prevent Prematurity and Stillbirth, Seattle, Washington.,Department of Global Health, University of Washington, Seattle
| | | | | | | | - Stephanie Schrag
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
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11
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Jousset AB, Bonnin RA, Rosinski-Chupin I, Girlich D, Cuzon G, Cabanel N, Frech H, Farfour E, Dortet L, Glaser P, Naas T. A 4.5-Year Within-Patient Evolution of a Colistin-Resistant Klebsiella pneumoniae Carbapenemase–Producing K. pneumoniae Sequence Type 258. Clin Infect Dis 2018; 67:1388-1394. [DOI: 10.1093/cid/ciy293] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 04/09/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Agnès B Jousset
- Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique–Hôpitaux de Paris (AP-HP), Paris
- Associated French National Reference Center for Antibiotic Resistance, Paris
- Faculty of Medicine, Paris-Sud University, Le Kremlin-Bicêtre, Paris
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
| | - Rémy A Bonnin
- Associated French National Reference Center for Antibiotic Resistance, Paris
- Faculty of Medicine, Paris-Sud University, Le Kremlin-Bicêtre, Paris
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
| | - Isabelle Rosinski-Chupin
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
- Centre de la Recherche Scientifique, Unité mixte de recherche, Paris
| | - Delphine Girlich
- Faculty of Medicine, Paris-Sud University, Le Kremlin-Bicêtre, Paris
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
| | - Gaëlle Cuzon
- Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique–Hôpitaux de Paris (AP-HP), Paris
- Associated French National Reference Center for Antibiotic Resistance, Paris
- Faculty of Medicine, Paris-Sud University, Le Kremlin-Bicêtre, Paris
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
| | - Nicolas Cabanel
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
- Centre de la Recherche Scientifique, Unité mixte de recherche, Paris
| | - Hélène Frech
- Department of Biology, Hôpital de Poissy–Saint-Germain-en-Laye, Poissy
| | - Eric Farfour
- Department of Microbiology, Hôpital Foch, Suresnes, France
| | - Laurent Dortet
- Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique–Hôpitaux de Paris (AP-HP), Paris
- Associated French National Reference Center for Antibiotic Resistance, Paris
- Faculty of Medicine, Paris-Sud University, Le Kremlin-Bicêtre, Paris
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
| | - Philippe Glaser
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
- Centre de la Recherche Scientifique, Unité mixte de recherche, Paris
| | - Thierry Naas
- Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique–Hôpitaux de Paris (AP-HP), Paris
- Associated French National Reference Center for Antibiotic Resistance, Paris
- Faculty of Medicine, Paris-Sud University, Le Kremlin-Bicêtre, Paris
- Joint Research Unit Evolution and Ecology of Resistance to Antibiotics, Institut Pasteur, AP-HP, University Paris Sud, Paris
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12
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Shabayek S, Spellerberg B. Group B Streptococcal Colonization, Molecular Characteristics, and Epidemiology. Front Microbiol 2018; 9:437. [PMID: 29593684 PMCID: PMC5861770 DOI: 10.3389/fmicb.2018.00437] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/26/2018] [Indexed: 11/13/2022] Open
Abstract
Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of serious neonatal infections. GBS is an opportunistic commensal constituting a part of the intestinal and vaginal physiologic flora and maternal colonization is the principal route of GBS transmission. GBS is a pathobiont that converts from the asymptomatic mucosal carriage state to a major bacterial pathogen causing severe invasive infections. At present, as many as 10 serotypes (Ia, Ib, and II–IX) are recognized. The aim of the current review is to shed new light on the latest epidemiological data and clonal distribution of GBS in addition to discussing the most important colonization determinants at a molecular level. The distribution and predominance of certain serotypes is susceptible to variations and can change over time. With the availability of multilocus sequence typing scheme (MLST) data, it became clear that GBS strains of certain clonal complexes possess a higher potential to cause invasive disease, while other harbor mainly colonizing strains. Colonization and persistence in different host niches is dependent on the adherence capacity of GBS to host cells and tissues. Bacterial biofilms represent well-known virulence factors with a vital role in persistence and chronic infections. In addition, GBS colonization, persistence, translocation, and invasion of host barriers are largely dependent on their adherence abilities to host cells and extracellular matrix proteins (ECM). Major adhesins mediating GBS interaction with host cells include the fibrinogen-binding proteins (Fbs), the laminin-binding protein (Lmb), the group B streptococcal C5a peptidase (ScpB), the streptococcal fibronectin binding protein A (SfbA), the GBS immunogenic bacterial adhesin (BibA), and the hypervirulent adhesin (HvgA). These adhesins facilitate persistent and intimate contacts between the bacterial cell and the host, while global virulence regulators play a major role in the transition to invasive infections. This review combines for first time epidemiological data with data on adherence and colonization for GBS. Investigating the epidemiology along with understanding the determinants of mucosal colonization and the development of invasive disease at a molecular level is therefore important for the development of strategies to prevent invasive GBS disease worldwide.
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Affiliation(s)
- Sarah Shabayek
- Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany
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13
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Abstract
Group B streptococcus (GBS) is one of the most common causes of neonatal sepsis and meningitis. Intra-partum antibiotic prophylaxis does not play a significant role in reducing the risk of GBS late-onset disease. One of the proposed mechanisms for GBS late-onset disease is infection through contaminated breast milk. Infants in whom breast milk is thought to be the source for GBS late-onset disease are more heavily colonised and reports suggest they have a higher recurrence rate compared to infants with other potential sources. There is no consensus whether the breast milk of mothers of infants with GBS late-onset disease, especially those with recurrent episodes, should be tested for GBS. In addition, recommendations differ on whether breast-feeding should be interrupted or breast milk pasteurised, or whether the mother and infant should be treated for colonisation. In this review we discuss these different approaches.
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Affiliation(s)
- Petra Zimmermann
- Infectious Diseases Unit, The Royal Children's Hospital Melbourne, Parkville, Australia; Department of Paediatrics, The University of Melbourne, Parkville, Australia; Infectious Diseases & Microbiology Research Group, Murdoch Children's Research Institute, Parkville, Australia
| | - Amanda Gwee
- Infectious Diseases Unit, The Royal Children's Hospital Melbourne, Parkville, Australia; Department of Paediatrics, The University of Melbourne, Parkville, Australia; Infectious Diseases & Microbiology Research Group, Murdoch Children's Research Institute, Parkville, Australia
| | - Nigel Curtis
- Infectious Diseases Unit, The Royal Children's Hospital Melbourne, Parkville, Australia; Department of Paediatrics, The University of Melbourne, Parkville, Australia; Infectious Diseases & Microbiology Research Group, Murdoch Children's Research Institute, Parkville, Australia.
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14
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Bodi Winn C, Bakthavatchalu V, Esmail MY, Feng Y, Dzink-Fox J, Richey L, Perkins SE, Nordberg EK, Fox JG. Isolation and molecular characterization of group B Streptococcus from laboratory Long-Evans rats ( Rattus norvegicus) with and without invasive group B streptococcal disease. J Med Microbiol 2018; 67:97-109. [PMID: 29160197 DOI: 10.1099/jmm.0.000627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Purpose. Group B Streptococcus (S. agalactiae, GBS) is a Gram-positive opportunistic pathogen that inhabits the respiratory, urogenital and gastrointestinal tracts of humans and animals. Maternal colonization of GBS is a risk factor for a spectrum of clinical diseases in humans and a principle cause of neonatal meningitis and septicaemia.Methodology. We describe polymicrobial sepsis including GBS in two gravid adult female Long-Evans rats experiencing acute mortality from a colony of long-term breeding pairs. Fluorescent in situ hybridization confirmed GBS association with pathological changes in affected tissues, including the heart and uterus.Results. Characterization of seven GBS strains obtained from clinically affected and non-affected animals indicated similar antibiotic resistance and susceptibility patterns to that of human strains of GBS. The rat strains have virulence factors known to contribute to pathogenicity, and shared serotypes with human invasive isolates. Phylogenetic analyses revealed that one rat-derived GBS strain was more closely related to human-derived strains than other rat-derived strains, strengthening the notion that interspecies transmission is possible.Conclusions. To our knowledge, this is the first investigation of genotypic and phenotypic features of rat-derived GBS strains and their comparison to human- and other animal-derived GBS strains. Since GBS commonly colonizes commercially available rats, its exclusion as a potential pathogen for immunocompromised or stressed animals is recommended.
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Affiliation(s)
- Caroline Bodi Winn
- Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Vasudevan Bakthavatchalu
- Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Michael Y Esmail
- Division of Laboratory Animal Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Yan Feng
- Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - JoAnn Dzink-Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Lauren Richey
- Division of Laboratory Animal Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Scott E Perkins
- Division of Laboratory Animal Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Eric K Nordberg
- Biocomplexity Institute, Virginia Tech, Blacksburg, VA 24060, USA
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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15
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Kolter J, Henneke P. Codevelopment of Microbiota and Innate Immunity and the Risk for Group B Streptococcal Disease. Front Immunol 2017; 8:1497. [PMID: 29209311 PMCID: PMC5701622 DOI: 10.3389/fimmu.2017.01497] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 10/24/2017] [Indexed: 12/14/2022] Open
Abstract
The pathogenesis of neonatal late-onset sepsis (LOD), which manifests between the third day and the third month of life, remains poorly understood. Group B Streptococcus (GBS) is the most important cause of LOD in infants without underlying diseases or prematurity and the third most frequent cause of meningitis in the Western world. On the other hand, GBS is a common intestinal colonizer in infants. Accordingly, despite its adaption to the human lower gastrointestinal tract, GBS has retained its potential virulence and its transition from a commensal to a dangerous pathogen is unpredictable in the individual. Several cellular innate immune mechanisms, in particular Toll-like receptors, the inflammasome and the cGAS pathway, are engaged by GBS effectors like nucleic acids. These are likely to impact on the GBS-specific host resistance. Given the long evolution of streptococci as a normal constituent of the human microbiota, the emergence of GBS as the dominant neonatal sepsis cause just about 50 years ago is remarkable. It appears that intensive usage of tetracycline starting in the 1940s has been a selection advantage for the currently dominant GBS clones with superior adhesive and invasive properties. The historical replacement of Group A by Group B streptococci as a leading neonatal pathogen and the higher frequency of other β-hemolytic streptococci in areas with low GBS prevalence suggests the existence of a confined streptococcal niche, where locally competing streptococcal species are subject to environmental and immunological selection pressure. Thus, it seems pivotal to resolve neonatal innate immunity at mucous surfaces and its impact on microbiome composition and quality, i.e., genetic heterogeneity and metabolism, at the microanatomical level. Then, designer pro- and prebiotics, such as attenuated strains of GBS, and oligonucleotide priming of mucosal immunity may unfold their potential and facilitate adaptation of potentially hazardous streptococci as part of a beneficial local microbiome, which is stabilized by mucocutaneous innate immunity.
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Affiliation(s)
- Julia Kolter
- Center for Chronic Immunodeficiency (CCI), Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Philipp Henneke
- Center for Chronic Immunodeficiency (CCI), Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Pediatrics and Adolescent Medicine, Medical Center - University of Freiburg, Freiburg, Germany
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16
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Skolnik K, Nguyen A, Thornton CS, Waddell B, Williamson T, Rabin HR, Parkins MD. Group B streptococcus (GBS) is an important pathogen in human disease- but what about in cystic fibrosis? BMC Infect Dis 2017; 17:660. [PMID: 28969684 PMCID: PMC5625721 DOI: 10.1186/s12879-017-2729-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 09/12/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is a common commensal capable of causing severe invasive infections. Most GBS infections occur in neonates (often as pneumonia). GBS can also cause infection in adults with diabetes and other immunological impairments but rarely leads to pneumonia in adults. GBS has occasionally been found in the sputum of Cystic Fibrosis (CF) patients, an inherited condition known for progressive lung disease. However, the epidemiology and clinical significance of GBS in CF are not understood. METHODS We retrospectively reviewed a large single-centre adult CF population with an associated comprehensive, prospectively collected bacterial biobank beginning in 1978. We identified all individuals with GBS isolated from their sputum on at least one occasion. The primary outcome was risk of pulmonary exacerbation (PEx) at the time of the first GBS isolate compared to the preceding visit. Secondary outcomes included determining: prevalence of GBS infection in a CF population, whether GBS infections where transient or persistent, whether GBS strains were shared among patients, change in % predicted FEV1 at the time of GBS isolate compared to the preceding visit, PEx frequency after the first GBS isolate, change in % predicted FEV1 after the first GBS isolate, and complications of GBS infection. RESULTS GBS was uncommon, infecting 3.5% (11/318) adults within our cohort. Only three individuals developed persistent GBS infection, all lasting > 12 months. There were no shared GBS strains among patients. PEx risk was not increased at initial GBS isolation (RR 5.0, CI 0.69-36.1, p=0.10). In the two years preceding initial GBS isolation compared to the two following years, there was no difference in PEx frequency (median 2, range 0-4 vs 1, range 0 to 5, respectively, p=0.42) or lung function decline, as measured by % predicted FEV1, (median -1.0%, range -19 to 7% vs median -6.0%, range -18 to 22%, p=0.86). There were no invasive GBS infections. CONCLUSION In adults with CF, GBS is uncommon and is generally a transient colonizer of the lower airways. Despite the presence of structural lung disease and impaired innate immunity in CF, incident GBS infection did not increase PEx risk, PEx frequency, rate of lung function decline, or other adverse clinical outcomes.
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Affiliation(s)
- Kate Skolnik
- Department of Medicine, University of Calgary, 7007 14th Street SW, Calgary, AB, T2V 1P9, Canada. .,Department of Community Health Sciences, University of Calgary, Third Floor TRW Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
| | - Austin Nguyen
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Christina S Thornton
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Barbara Waddell
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Tyler Williamson
- Department of Community Health Sciences, University of Calgary, Third Floor TRW Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Harvey R Rabin
- Department of Medicine, University of Calgary, 7007 14th Street SW, Calgary, AB, T2V 1P9, Canada.,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Michael D Parkins
- Department of Medicine, University of Calgary, 7007 14th Street SW, Calgary, AB, T2V 1P9, Canada.,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
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17
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Parallel Evolution of Group B Streptococcus Hypervirulent Clonal Complex 17 Unveils New Pathoadaptive Mutations. mSystems 2017; 2:mSystems00074-17. [PMID: 28904998 PMCID: PMC5585690 DOI: 10.1128/msystems.00074-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/10/2017] [Indexed: 12/21/2022] Open
Abstract
The incidence of group B Streptococcus (GBS) neonatal disease continues to be a significant cause of concern worldwide. Strains belonging to clonal complex 17 (CC17) are the most frequently responsible for GBS infections in neonates, especially among late-onset disease cases. Therefore, we undertook the largest genomic study of GBS CC17 strains to date to decipher the genetic bases of their remarkable colonization and infection ability. We show that crucial functions involved in different steps of the colonization or infection process of GBS are distinctly mutated during the adaptation of CC17 to the human host. In particular, our results implicate the CovRS two-component regulator of virulence in the differentiation between carriage- and disease-associated isolates. Not only does this work raise important implications for the ongoing development of a vaccine against GBS but might also drive the discovery of key functions for GBS adaptation and pathogenesis that have been overlooked until now. Group B Streptococcus (GBS) is a commensal of the gastrointestinal and genitourinary tracts, while a prevailing cause of neonatal disease worldwide. Of the various clonal complexes (CCs), CC17 is overrepresented in GBS-infected newborns for reasons that are still largely unknown. Here, we report a comprehensive genomic analysis of 626 CC17 isolates collected worldwide, identifying the genetic traits behind their successful adaptation to humans and the underlying differences between carriage and clinical strains. Comparative analysis with 923 GBS genomes belonging to CC1, CC19, and CC23 revealed that the evolution of CC17 is distinct from that of other human-adapted lineages and recurrently targets functions related to nucleotide and amino acid metabolism, cell adhesion, regulation, and immune evasion. We show that the most distinctive features of disease-specific CC17 isolates were frequent mutations in the virulence-associated CovS and Stk1 kinases, underscoring the crucial role of the entire CovRS regulatory pathway in modulating the pathogenicity of GBS. Importantly, parallel and convergent evolution of major components of the bacterial cell envelope, such as the capsule biosynthesis operon, the pilus, and Rib, reflects adaptation to host immune pressures and should be taken into account in the ongoing development of a GBS vaccine. The presence of recurrent targets of evolution not previously implicated in virulence also opens the way for uncovering new functions involved in host colonization and GBS pathogenesis. IMPORTANCE The incidence of group B Streptococcus (GBS) neonatal disease continues to be a significant cause of concern worldwide. Strains belonging to clonal complex 17 (CC17) are the most frequently responsible for GBS infections in neonates, especially among late-onset disease cases. Therefore, we undertook the largest genomic study of GBS CC17 strains to date to decipher the genetic bases of their remarkable colonization and infection ability. We show that crucial functions involved in different steps of the colonization or infection process of GBS are distinctly mutated during the adaptation of CC17 to the human host. In particular, our results implicate the CovRS two-component regulator of virulence in the differentiation between carriage- and disease-associated isolates. Not only does this work raise important implications for the ongoing development of a vaccine against GBS but might also drive the discovery of key functions for GBS adaptation and pathogenesis that have been overlooked until now. Author Video: An author video summary of this article is available.
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18
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Harrell MI, Burnside K, Whidbey C, Vornhagen J, Adams Waldorf KM, Rajagopal L. Exploring the Pregnant Guinea Pig as a Model for Group B Streptococcus Intrauterine Infection. ACTA ACUST UNITED AC 2017; 2. [PMID: 29034376 PMCID: PMC5635843 DOI: 10.4172/2576-1420.1000109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Infection of the amniotic cavity remains a major cause of preterm birth, stillbirth, fetal injury and early onset, fulminant infections in newborns. Currently, there are no effective therapies to prevent in utero infection and consequent co-morbidities. This is in part due to the lack of feasible and appropriate animal models to understand mechanisms that lead to in utero infections. Use of mouse and rat models do not fully recapitulate human pregnancy, while pregnant nonhuman primate models are limited by ethical considerations, technical constraints, and cost. Given these limitations, the guinea pig is an attractive animal model for studying pregnancy infections, particularly as the placental structure is quite similar to the human placenta. Here, we describe our studies that explored the pregnant guinea pig as a model to study in utero Group B Streptococci (GBS) infections. We observed that intrauterine inoculation of wild type GBS in pregnant guinea pigs resulted in bacterial invasion and dissemination to the placenta, amniotic fluid and fetal organs. Also, hyperhemolytic GBS such as those lacking the hemolysin repressor CovR/S showed increased dissemination into the amniotic fluid and fetal organs such as the fetal lung and brain. These results are similar to those observed in mouse and non-human primate models of in utero infection, and support use of the guinea pig as a model for studying GBS infections in pregnancy.
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Affiliation(s)
- Maria I Harrell
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Kellie Burnside
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Christopher Whidbey
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America.,Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Jay Vornhagen
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America.,Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Kristina M Adams Waldorf
- Department of Global Health, University of Washington, Seattle, Washington, United States of America.,Department of Obstetrics and Gynecology, School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America.,Department of Global Health, University of Washington, Seattle, Washington, United States of America
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19
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Sullivan MJ, Leclercq SY, Ipe DS, Carey AJ, Smith JP, Voller N, Cripps AW, Ulett GC. Effect of the Streptococcus agalactiae Virulence Regulator CovR on the Pathogenesis of Urinary Tract Infection. J Infect Dis 2017; 215:475-483. [PMID: 28011914 DOI: 10.1093/infdis/jiw589] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/02/2016] [Indexed: 12/22/2022] Open
Abstract
Background Streptococcus agalactiae can cause urinary tract infection (UTI). The role of the S. agalactiae global virulence regulator, CovR, in UTI pathogenesis is unknown. Methods We used murine and human bladder uroepithelial cell models of UTI and S. agalactiae mutants in covR and related factors, including β-hemolysin/cytolysin (β-h/c), surface-anchored adhesin HvgA, and capsule to study the role of CovR in UTI. Results We found that covR-deficient serotype III S. agalactiae 874391 was significantly attenuated for colonization in mice and adhesion to uroepithelial cells. Mice infected with covR-deficient S. agalactiae produced less proinflammatory cytokines than those infected with wild-type 874391. Acute cytotoxicity in uroepithelial cells triggered by covR-deficient but not wild-type 874391 was associated with significant caspase 3 activation. Mechanistically, covR mutation significantly altered the expression of several genes in S. agalactiae 874391 that encode key virulence factors, including β-h/c and HvgA, but not capsule. Subsequent mutational analyses revealed that HvgA and capsule, but not the β-h/c, exerted significant effects on colonization of the murine urinary tract in vivo. Conclusions S. agalactiae CovR promotes bladder infection and inflammation, as well as adhesion to and viability of uroepithelial cells. The pathogenesis of S. agalactiae UTI is complex, multifactorial, and influenced by virulence effects of CovR, HvgA, and capsule.
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Affiliation(s)
- Matthew J Sullivan
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Sophie Y Leclercq
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.,Research and Development Center, Ezequiel Dias Foundation (FUNED), Belo Horizonte, Brazil
| | - Deepak S Ipe
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Alison J Carey
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Joshua P Smith
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Nathan Voller
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.,School of Biological Sciences, University of East Anglia, Norwich Research Park, United Kingdom
| | - Allan W Cripps
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Glen C Ulett
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
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Almeida A, Alves-Barroco C, Sauvage E, Bexiga R, Albuquerque P, Tavares F, Santos-Sanches I, Glaser P. Persistence of a dominant bovine lineage of group B Streptococcus reveals genomic signatures of host adaptation. Environ Microbiol 2016; 18:4216-4229. [PMID: 27696631 DOI: 10.1111/1462-2920.13550] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/20/2016] [Accepted: 09/26/2016] [Indexed: 11/28/2022]
Abstract
Group B Streptococcus (GBS) is a host-generalist species, most notably causing disease in humans and cattle. However, the differential adaptation of GBS to its two main hosts, and the risk of animal to human infection remain poorly understood. Despite improvements in control measures across Europe, GBS is still one of the main causative agents of bovine mastitis in Portugal. Here, by whole-genome analysis of 150 bovine GBS isolates we discovered that a single CC61 clone is spreading throughout Portuguese herds since at least the early 1990s, having virtually replaced the previous GBS population. Mutations within an iron/manganese transporter were independently acquired by all of the CC61 isolates, underlining a key adaptive strategy to persist in the bovine host. Lateral transfer of bacteriocin production and antibiotic resistance genes also underscored the contribution of the microbial ecology and genetic pool within the bovine udder environment to the success of this clone. Compared to strains of human origin, GBS evolves twice as fast in bovines and undergoes recurrent pseudogenizations of human-adapted traits. Our work provides new insights into the potentially irreversible adaptation of GBS to the bovine environment.
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Affiliation(s)
- Alexandre Almeida
- Institut Pasteur, Unité Evolution et Ecologie de la Résistance aux Antibiotiques, Paris, France.,CNRS UMR 3525, Paris, France.,Université Pierre et Marie Curie, Paris, France
| | - Cinthia Alves-Barroco
- Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, UCIBIO - Unidade de Ciências Biomoleculares Aplicadas, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Elisabeth Sauvage
- Institut Pasteur, Unité Evolution et Ecologie de la Résistance aux Antibiotiques, Paris, France.,CNRS UMR 3525, Paris, France
| | - Ricardo Bexiga
- Faculdade de Medicina Veterinária, Centro de Investigação Interdisciplinar em Sanidade Animal, Universidade de Lisboa, Lisboa, Portugal
| | - Pedro Albuquerque
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
| | - Fernando Tavares
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal.,Faculdade de Ciências, Departamento de Biologia, Universidade do Porto, Porto, Portugal
| | - Ilda Santos-Sanches
- Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, UCIBIO - Unidade de Ciências Biomoleculares Aplicadas, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Philippe Glaser
- Institut Pasteur, Unité Evolution et Ecologie de la Résistance aux Antibiotiques, Paris, France.,CNRS UMR 3525, Paris, France
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21
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Maternal colonization with Streptococcus agalactiae and associated stillbirth and neonatal disease in coastal Kenya. Nat Microbiol 2016; 1:16067. [PMID: 27572968 DOI: 10.1038/nmicrobiol.2016.67] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 04/16/2016] [Indexed: 12/20/2022]
Abstract
Streptococcus agalactiae (group B streptococcus, GBS) causes neonatal disease and stillbirth, but its burden in sub-Saharan Africa is uncertain. We assessed maternal recto-vaginal GBS colonization (7,967 women), stillbirth and neonatal disease. Whole-genome sequencing was used to determine serotypes, sequence types and phylogeny. We found low maternal GBS colonization prevalence (934/7,967, 12%), but comparatively high incidence of GBS-associated stillbirth and early onset neonatal disease (EOD) in hospital (0.91 (0.25-2.3)/1,000 births and 0.76 (0.25-1.77)/1,000 live births, respectively). However, using a population denominator, EOD incidence was considerably reduced (0.13 (0.07-0.21)/1,000 live births). Treated cases of EOD had very high case fatality (17/36, 47%), especially within 24 h of birth, making under-ascertainment of community-born cases highly likely, both here and in similar facility-based studies. Maternal GBS colonization was less common in women with low socio-economic status, HIV infection and undernutrition, but when GBS-colonized, they were more probably colonized by the most virulent clone, CC17. CC17 accounted for 267/915 (29%) of maternal colonizing (265/267 (99%) serotype III; 2/267 (0.7%) serotype IV) and 51/73 (70%) of neonatal disease cases (all serotype III). Trivalent (Ia/II/III) and pentavalent (Ia/Ib/II/III/V) vaccines would cover 71/73 (97%) and 72/73 (99%) of disease-causing serotypes, respectively. Serotype IV should be considered for inclusion, with evidence of capsular switching in CC17 strains.
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