1
|
Furfaro LL, Chang BJ, Kahler CM, Payne MS. Genomic characterisation of perinatal Western Australian Streptococcus agalactiae isolates. PLoS One 2019; 14:e0223256. [PMID: 31577825 PMCID: PMC6774530 DOI: 10.1371/journal.pone.0223256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/17/2019] [Indexed: 11/18/2022] Open
Abstract
As a leading cause of neonatal sepsis, Streptococcus agalactiae, commonly known as Group B Streptococcus, is a major neonatal pathogen. Current global screening practices employ risk- or culture-based protocols for detection of these organisms. In Western Australia (WA), universal culture-based screening is provided, with subsequent intrapartum antibiotic prophylaxis for all S. agalactiae-positive women during labour. Widespread antibiotic exposure is not ideal and this is one of the factors driving development of vaccines against S. agalactiae. Vaccine candidates have focused on the capsule, surface proteins and pilus types, however, capsule serotypes are known to vary geographically. The aim of this study was to use genome sequencing to gain an understanding of the circulating genotypes in WA, and to assess variations in the associated gene pools. We sequenced 141 antenatal carriage (vaginal/rectal) isolates and 10 neonatal invasive disease isolates from WA. Based on the global PubMLST database, the 151 strains were characterised into 30 sequence types, with clustering of these mainly into clonal complexes 1, 12, 17, 19 and 23. Of the genes encoding eleven surface proteins that were analysed, the most prevalent were fbp, lmb and scpB which were present in ≥ 98% of isolates. A cluster of non-haemolytic isolates, one of which was a neonatal invasive disease isolate, appeared to lack the entire cyl locus. Admixture analysis of population structure revealed evidence of genetic transfer among the WA isolates across structural groups. When compared against the PubMLST S. agalactiae data, WA isolates showed high levels of strain diversity with minimal apparent clustering. This is the first whole genome sequence study of WA S. agalactiae isolates and also represents the first addition of Australian isolate data to PubMLST. This report provides insight into the distribution and diversity of vaccine targets of S. agalactiae within Western Australia, indicating that the most appropriate capsular vaccine for this population would be the proposed pentavalent (Cps Ia, Ib, II, III and V) preparation, whilst vaccines targeting surface proteins should ideally utilise Fbp, Lmb and/or ScpB.
Collapse
Affiliation(s)
- Lucy L. Furfaro
- The School of Medicine, Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, Western Australia, Australia
- * E-mail:
| | - Barbara J. Chang
- The School of Biomedical Sciences, The Marshall Centre for Infectious Diseases Research and Training, The University of Western Australia, Perth, Western Australia, Australia
| | - Charlene M. Kahler
- The School of Biomedical Sciences, The Marshall Centre for Infectious Diseases Research and Training, The University of Western Australia, Perth, Western Australia, Australia
| | - Matthew S. Payne
- The School of Medicine, Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, Western Australia, Australia
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Lawn JE, Bianchi-Jassir F, Russell NJ, Kohli-Lynch M, Tann CJ, Hall J, Madrid L, Baker CJ, Bartlett L, Cutland C, Gravett MG, Heath PT, Ip M, Le Doare K, Madhi SA, Rubens CE, Saha SK, Schrag S, Sobanjo-ter Meulen A, Vekemans J, Seale AC. Group B Streptococcal Disease Worldwide for Pregnant Women, Stillbirths, and Children: Why, What, and How to Undertake Estimates? Clin Infect Dis 2017; 65:S89-S99. [PMID: 29117323 PMCID: PMC5850012 DOI: 10.1093/cid/cix653] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Improving maternal, newborn, and child health is central to Sustainable Development Goal targets for 2030, requiring acceleration especially to prevent 5.6 million deaths around the time of birth. Infections contribute to this burden, but etiological data are limited. Group B Streptococcus (GBS) is an important perinatal pathogen, although previously focus has been primarily on liveborn children, especially early-onset disease. In this first of an 11-article supplement, we discuss the following: (1) Why estimate the worldwide burden of GBS disease? (2) What outcomes of GBS in pregnancy should be included? (3) What data and epidemiological parameters are required? (4) What methods and models can be used to transparently estimate this burden of GBS? (5) What are the challenges with available data? and (6) How can estimates address data gaps to better inform GBS interventions including maternal immunization? We review all available GBS data worldwide, including maternal GBS colonization, risk of neonatal disease (with/without intrapartum antibiotic prophylaxis), maternal GBS disease, neonatal/infant GBS disease, and subsequent impairment, plus GBS-associated stillbirth, preterm birth, and neonatal encephalopathy. We summarize our methods for searches, meta-analyses, and modeling including a compartmental model. Our approach is consistent with the World Health Organization (WHO) Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER), published in The Lancet and the Public Library of Science (PLoS). We aim to address priority epidemiological gaps highlighted by WHO to inform potential maternal vaccination.
Collapse
Affiliation(s)
- Joy E Lawn
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Fiorella Bianchi-Jassir
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Neal J Russell
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom
- King’s College London, United Kingdom
| | - 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
| | - Cally J Tann
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom
- Neonatal Medicine, University College London Hospitals NHS Foundation Trust, United Kingdom
| | - Jennifer Hall
- Department of Reproductive Health Research, University College London Institute for Women’s Health, United Kingdom
| | - Lola Madrid
- Maternal, Adolescent, Reproductive and Child Health Centre, London School of Hygiene & Tropical Medicine, United Kingdom
- ISGlobal, Barcelona Centre for International Health Research, Hospital Clinic–University of Barcelona, Spain
| | - 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, Johannesburg, South Africa
| | - Michael G Gravett
- Global Alliance to Prevent Prematurity and Stillbirth
- Department of Obstetrics and Gynecology, University of Washington, Seattle
| | - Paul T Heath
- Vaccine Institute, Institute for Infection and Immunity, St George’s Hospital, University of London and St George’s University Hospitals NHS Foundation Trust, United Kingdom
| | - 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 Hospital, University of London and St George’s University Hospitals NHS Foundation Trust, United Kingdom
- Centre for International Child Health, Imperial College London, 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, Johannesburg, South Africa
- National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Craig E Rubens
- Global Alliance to Prevent Prematurity and Stillbirth
- 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
| | | | | | - 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
| |
Collapse
|
4
|
Campisi E, Rinaudo CD, Donati C, Barucco M, Torricelli G, Edwards MS, Baker CJ, Margarit I, Rosini R. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages. Sci Rep 2016; 6:29799. [PMID: 27411639 PMCID: PMC4944191 DOI: 10.1038/srep29799] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/21/2016] [Indexed: 11/10/2022] Open
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV.
Collapse
Affiliation(s)
- Edmondo Campisi
- GSK Vaccines s.r.l., Siena, Italy.,Sapienza, Università di Roma, Rome, Italy
| | | | - Claudio Donati
- Department of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Mara Barucco
- GSK Vaccines s.r.l., Siena, Italy.,Department of physics "Enrico Fermi", University of Pisa, Pisa, Italy
| | | | - Morven S Edwards
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Carol J Baker
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Department Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | | | | |
Collapse
|
5
|
Fléchard M, Gilot P. Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae. Microbiology (Reading) 2014; 160:1298-1315. [DOI: 10.1099/mic.0.077628-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We have referenced and described Streptococcus agalactiae transposable elements encoding DDE transposases. These elements belonged to nine families of insertion sequences (ISs) and to a family of conjugative transposons (TnGBSs). An overview of the physiological impact of the insertion of all these elements is provided. DDE-transposable elements affect S. agalactiae in a number of aspects of its capability to adapt to various environments and modulate the expression of several virulence genes, the scpB–lmB genomic region and the genes involved in capsule expression and haemolysin transport being the targets of several different mobile elements. The referenced mobile elements modify S. agalactiae behaviour by transferring new gene(s) to its genome, by modifying the expression of neighbouring genes at the integration site or by promoting genomic rearrangements. Transposition of some of these elements occurs in vivo, suggesting that by dynamically regulating some adaptation and/or virulence genes, they improve the ability of S. agalactiae to reach different niches within its host and ensure the ‘success’ of the infectious process.
Collapse
Affiliation(s)
- Maud Fléchard
- Biochimie et Génétique Moléculaire Bactérienne, Institut des Sciences de la Vie, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Philippe Gilot
- INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université de Tours, UMR1282 Infectiologie et Santé Publique, Bactéries et Risque Materno-Foetal, F-37032 Tours, France
| |
Collapse
|
6
|
Pinto TCA, Costa NS, Vianna Souza AR, Silva LGD, Corrêa ABDA, Fernandes FG, Oliveira ICM, Mattos MCD, Rosado AS, Benchetrit LC. Distribution of serotypes and evaluation of antimicrobial susceptibility among human and bovine Streptococcus agalactiae strains isolated in Brazil between 1980 and 2006. Braz J Infect Dis 2013; 17:131-6. [PMID: 23453948 PMCID: PMC9427402 DOI: 10.1016/j.bjid.2012.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 09/23/2012] [Accepted: 09/24/2012] [Indexed: 12/27/2022] Open
Abstract
Streptococcus agalactiae is a common agent of clinical and subclinical bovine mastitis and an important cause of human infections, mainly among pregnant women, neonates and nonpregnant adults with underlying diseases. The present study describes the genetic and phenotypic diversity among 392 S. agalactiae human and bovine strains isolated between 1980 and 2006 in Brazil. The most prevalent serotypes were Ia, II, III and V and all the strains were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampicin and tetracycline was observed. Among the erythromycin resistant strains, mefA/E, ermA and, mainly, ermB gene were detected, and a shift of prevalence from the macrolide resistance phenotype to the macrolide-lincosamide-streptogramin B resistance phenotype over the years was observed. The 23 macrolide-resistant strains showed 19 different pulsed-field gel electrophoresis profiles. Regarding macrolide resistance, a major concern in S. agalactiae epidemiology, the present study describes an increase in erythromycin resistance from the 80s to the 90s followed by a decrease in the 2000–2006 period. Also, the genetic heterogeneity described points out that erythromycin resistance in Brazil is rather due to horizontal gene transmission than to spreading of specific macrolide-resistant clones.
Collapse
Affiliation(s)
- Tatiana Castro Abreu Pinto
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Usein CR, Grigore L, Georgescu R, Cristea V, Bãltoiu M, Strãuţ M. Molecular characterization of adult-colonizing Streptococcus agalactiae from an area-based surveillance study in Romania. Eur J Clin Microbiol Infect Dis 2012; 31:2301-10. [DOI: 10.1007/s10096-012-1569-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 01/26/2012] [Indexed: 11/30/2022]
|
8
|
Haguenoer E, Baty G, Pourcel C, Lartigue MF, Domelier AS, Rosenau A, Quentin R, Mereghetti L, Lanotte P. A multi locus variable number of tandem repeat analysis (MLVA) scheme for Streptococcus agalactiae genotyping. BMC Microbiol 2011; 11:171. [PMID: 21794143 PMCID: PMC3163538 DOI: 10.1186/1471-2180-11-171] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 07/27/2011] [Indexed: 11/10/2022] Open
Abstract
Background Multilocus sequence typing (MLST) is currently the reference method for genotyping Streptococcus agalactiae strains, the leading cause of infectious disease in newborns and a major cause of disease in immunocompromised children and adults. We describe here a genotyping method based on multiple locus variable number of tandem repeat (VNTR) analysis (MLVA) applied to a population of S. agalactiae strains of various origins characterized by MLST and serotyping. Results We studied a collection of 186 strains isolated from humans and cattle and three reference strains (A909, NEM316 and 2603 V/R). Among 34 VNTRs, 6 polymorphic VNTRs loci were selected for use in genotyping of the bacterial population. The MLVA profile consists of a series of allele numbers, corresponding to the number of repeats at each VNTR locus. 98 MLVA genotypes were obtained compared to 51 sequences types generated by MLST. The MLVA scheme generated clusters which corresponded well to the main clonal complexes obtained by MLST. However it provided a higher discriminatory power. The diversity index obtained with MLVA was 0.960 compared to 0.881 with MLST for this population of strains. Conclusions The MLVA scheme proposed here is a rapid, cheap and easy genotyping method generating results suitable for exchange and comparison between different laboratories and for the epidemiologic surveillance of S. agalactiae and analyses of outbreaks.
Collapse
Affiliation(s)
- Eve Haguenoer
- Université François-Rabelais de Tours, UFR de Médecine, EA 3854 Bactéries et risque materno-fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, Tours, France
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Diversity of prophage DNA regions of Streptococcus agalactiae clonal lineages from adults and neonates with invasive infectious disease. PLoS One 2011; 6:e20256. [PMID: 21633509 PMCID: PMC3102099 DOI: 10.1371/journal.pone.0020256] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 04/22/2011] [Indexed: 11/19/2022] Open
Abstract
The phylogenetic position and prophage DNA content of the genomes of 142 S. agalactiae (group-B streptococcus, GBS) isolates responsible for bacteremia and meningitis in adults and neonates were studied and compared. The distribution of the invasive isolates between the various serotypes, sequence types (STs) and clonal complexes (CCs) differed significantly between adult and neonatal isolates. Use of the neighbor-net algorithm with the PHI test revealed evidence for recombination in the population studied (PHI, P = 2.01 × 10(-6)), and the recombination-mutation ratio (R/M) was 6:7. Nevertheless, the estimated R/M ratio differed between CCs. Analysis of the prophage DNA regions of the genomes of the isolates assigned 90% of the isolates to five major prophage DNA groups: A to E. The mean number of prophage DNA fragments amplified per isolate varied from 2.6 for the isolates of prophage DNA group E to 4.0 for the isolates of prophage DNA group C. The isolates from adults and neonates with invasive diseases were distributed differently between the various prophage DNA groups (P < 0.00001). Group C prophage DNA fragments were found in 52% of adult invasive isolates, whereas 74% of neonatal invasive isolates had prophage DNA fragments of groups A and B. Differences in prophage DNA content were also found between serotypes, STs and CCs (P < 0.00001). All the ST-1 and CC1 isolates, mostly of serotype V, belonged to the prophage DNA group C, whereas 84% of the ST-17 and CC17 isolates, all of serotype III, belonged to prophage DNA groups A and B. These data indicate that the transduction mechanisms, i.e., gene transfer from one bacterium to another by a bacteriophage, underlying genetic recombination in S. agalactiae species, are specific to each intraspecies lineage and population of strains responsible for invasive diseases in adults and neonates.
Collapse
|
10
|
Clonal analysis of colonizing group B Streptococcus, serotype IV, an emerging pathogen in the United States. J Clin Microbiol 2010; 48:3100-4. [PMID: 20610684 DOI: 10.1128/jcm.00277-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Colonizing group B Streptococcus (GBS) capsular polysaccharide (CPS) type IV isolates were recovered from vaginal and rectal samples obtained from 97 (8.4%) nonpregnant women of 1,160 women enrolled in a U.S. multicenter GBS vaccine study from 2004 to 2008. Since this rate was much higher than the rate of prevalence of 0.4 to 0.6% that we found in previous studies, the isolates were analyzed by using surface protein profile identification, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) to characterize them and identify trends in DNA clonality and divergence. Of the 101 type IV isolates studied, 53 expressed alpha and group B protective surface (BPS) proteins, 27 expressed BPS only, 20 expressed alpha only, and 1 had no detectable surface proteins. The isolates spanned three PFGE macrorestriction profile groups, groups 37, 38, and 39, of which group 37 was predominant. The isolates in group 37 expressed the alpha and BPS proteins, while those in groups 38 and 39 expressed the alpha protein only, with two exceptions. MLST studies of selective isolates from the four protein profile groups showed that isolates expressing alpha,BPS or BPS only were of a new sequence type, sequence type 452, while those expressing alpha only or no proteins were mainly of a new sequence type, sequence type 459. Overall, our study revealed a limited diversity in surface proteins, MLST types, and DNA macrorestriction profiles for type IV GBS. There appeared to be an association between the MLST types and protein expression profiles. The increased prevalence of type IV GBS colonization suggested the possibility that this serotype may emerge as a GBS pathogen.
Collapse
|
11
|
Al Safadi R, Amor S, Hery-Arnaud G, Spellerberg B, Lanotte P, Mereghetti L, Gannier F, Quentin R, Rosenau A. Enhanced expression of lmb gene encoding laminin-binding protein in Streptococcus agalactiae strains harboring IS1548 in scpB-lmb intergenic region. PLoS One 2010; 5:e10794. [PMID: 20520730 PMCID: PMC2875397 DOI: 10.1371/journal.pone.0010794] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 05/01/2010] [Indexed: 11/19/2022] Open
Abstract
Group B streptococcus (GBS) is the main cause of neonatal sepsis and meningitis. Bacterial surface proteins play a major role in GBS binding to and invasion of different host surfaces. The scpB and lmb genes, coding for fibronectin-binding and laminin-binding surface proteins, are present in almost all human GBS isolates. The scpB-lmb intergenic region is a hot spot for integration of two mobile genetic elements (MGEs): the insertion element IS1548 or the group II intron GBSi1. We studied the structure of scpB-lmb intergenic region in 111 GBS isolates belonging to the intraspecies major clonal complexes (CCs). IS1548 was mostly found (72.2%) in CC19 serotype III strains recovered more specifically (92.3%) from neonatal meningitis. GBSi1 was principally found (70.6%) in CC17 strains, mostly (94.4%) of serotype III, but also (15.7%) in CC19 strains, mostly (87.5%) of serotype II. No MGE was found in most strains of the other CCs (76.0%), notably CC23, CC10 and CC1. Twenty-six strains representing these three genetic configurations were selected to investigate the transcription and expression levels of scpB and lmb genes. Quantitative RT-PCR showed that lmb transcripts were 5.0- to 9.6-fold higher in the group of strains with IS1548 than in the other two groups of strains (P<0.001). Accordingly, the binding ability to laminin was 3.8- to 6.6-fold higher in these strains (P≤0.001). Moreover, Lmb amount expressed on the cell surface was 2.4- to 2.7-fold greater in these strains (P<0.001). By contrast, scpB transcript levels and fibronectin binding ability were similar in the three groups of strains. Deletion of the IS1548 sequence between scpB and lmb genes in a CC19 serotype III GBS strain substantially reduced the transcription of lmb gene (13.5-fold), the binding ability to laminin (6.2-fold), and the expression of Lmb protein (5.0-fold). These data highlight the importance of MGEs in bacterial virulence and demonstrate the up-regulation of lmb gene by IS1548; the increased lmb gene expression observed in CC19 serotype III strains with IS1548 may play a role in their ability to cause neonatal meningitis and endocarditis.
Collapse
Affiliation(s)
- Rim Al Safadi
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
| | - Souheila Amor
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
| | - Geneviève Hery-Arnaud
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
| | - Barbara Spellerberg
- Institut für Medizinische Mikrobiologie und Hygiene, Universitäsklinikum Ulm, Ulm, Germany
| | - Philippe Lanotte
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
| | - Laurent Mereghetti
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
| | - François Gannier
- Unité Mixte de Recherche CNRS FRE 3092 Physiologie des Cellules Cardiaques et Vasculaires, UFR Sciences, Université François Rabelais de Tours, Tours, France
| | - Roland Quentin
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
- Service de Bactériologie et Hygiène Hospitalière, Hôpital Trousseau, CHRU de Tours, Tours, France
| | - Agnès Rosenau
- Equipe d'Accueil 3854 Bactéries et Risque Materno-Fœtal, Institut Fédératif de Recherche 136 Agents Transmissibles et Infectiologie, UFR Médecine, Université François Rabelais de Tours, Tours, France
- * E-mail:
| |
Collapse
|
12
|
Molecular characterization and prophage DNA contents of Streptococcus agalactiae strains isolated from adult skin and osteoarticular infections. J Clin Microbiol 2010; 48:1261-9. [PMID: 20181908 DOI: 10.1128/jcm.01820-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Skin and osteoarticular infections (SKI and OAI, respectively) account for almost one-third of Streptococcus agalactiae infections in nonpregnant adults. We evaluated the genetic diversity and phylogeny of 58 S. agalactiae strains responsible for adult SKI or OAI and of 61 S. agalactiae strains from cases of adult human colonization (HCol) by serotyping and multilocus sequence typing (MLST). We also assessed the prophage DNA content of the genomes of these strains by a PCR-based method. We found that 63% of SKI and 56% of OAI occurred in people aged 55 years and over. Overall, 71% of SKI strains were of serotype Ia or V, and 91% of OAI strains were of serotype Ia, III, or V. Strains of clonal complexes 1 and 23 (CC1 and CC23) were associated with 79% of SKI cases and 62% of OAI cases. Seven groups of strains, groups A, B, C, D, E, F, and G, were obtained by performing a hierarchical analysis on the basis of prophage DNA-PCR data. We found that 85% of CC1 strains clustered in DNA prophage group D, the group with the highest prophage DNA content (average, 4.4; average of absolute deviations [AVEDEV], 0.9). The CC23 strains displayed the greatest diversity in prophage DNA fragment content, but 47% of CC23 strains clustered in group B, which also had a high average prophage DNA content per strain (average, 2.3; AVEDEV, 0.6). Many (65%) of the OAI strains were in prophage DNA group D, whereas 83% of the SKI strains were in prophage DNA groups B and D. These data suggest that S. agalactiae strains from CC1 and CC23 may be subject to particular transduction mechanisms in gene recombination, rendering them particularly capable of invading the skin, bone, or joints in adults.
Collapse
|
13
|
Corrêa ABA, Américo MA, Oliveira ICM, Silva LG, de Mattos MC, Ferreira AMM, Couceiro JNSS, Fracalanzza SEL, Benchetrit LC. Virulence characteristics of genetically related isolates of group B streptococci from bovines and humans. Vet Microbiol 2009; 143:429-33. [PMID: 20045270 DOI: 10.1016/j.vetmic.2009.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 11/28/2009] [Accepted: 12/02/2009] [Indexed: 11/24/2022]
Abstract
The present study had the objective of evaluating the pathogenic potential of the genetically related strains of Streptococcus agalactiae no. 80427 (human origin) and no. 87159 (bovine origin), and comparing the results with two other strains isolated from bovine mastitis (no. 87244) and invasive human infection (no. 90356), with no genetic or epidemiologic relationship between them or with the first 2 isolates. Virulence genes hylB (hyaluronidase) and lmb (laminin-binding protein) were detected in the 4 strains, and genes bac (beta protein) and bca (alpha protein) were only detected in human strains. The protein profile obtained using SDS-PAGE did not indicate any differences between the 4 strains. No significant difference was detected between human and bovine strains in the assays of adherence to and invasion of 16HBe cells, as well as in the resistance assay for intracellular bacterial survival in macrophages. However, the strain 87159 exhibited a greater survival in the killing test with whole human blood and was more virulent in newborn mice than the 80427 strain. The strain 87244 was not virulent in mice. These data suggest that isolates of human and bovine origins may express similar virulence attributes, leading to a possible, however limited, dissemination.
Collapse
Affiliation(s)
- A B A Corrêa
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, RJ 21941-590, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Identification of an unusual pattern of global gene expression in group B Streptococcus grown in human blood. PLoS One 2009; 4:e7145. [PMID: 19774088 PMCID: PMC2745576 DOI: 10.1371/journal.pone.0007145] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 08/30/2009] [Indexed: 01/13/2023] Open
Abstract
Because passage of the bacterium to blood is a crucial step in the pathogenesis of many group B Streptococcus (GBS) invasive infections, we recently conducted a whole-genome transcriptome analysis during GBS incubation ex vivo with human blood. In the current work, we sought to analyze in detail the difference in GBS gene expression that occurred in one blood sample (donor A) relative to other blood samples. We incubated GBS strain NEM316 with fresh heparinized human blood obtained from healthy volunteers, and analyzed GBS genome expression and cytokine production. Principal component analysis identified extensive clustering of the transcriptome data among all samples at time 0. In striking contrast, the whole bacterial gene expression in the donor A blood sample was significantly different from the gene expression in all other blood samples studied, both after 30 and 90 min of incubation. More genes were up-regulated in donor A blood relative to the other samples, at 30 min and 90 min. Furthermore, there was significant variation in transcript levels between donor A blood and other blood samples. Notably, genes with the highest transcript levels in donor A blood were those involved in carbohydrate metabolism. We also discovered an unusual production of proinflammatory and immunomodulatory cytokines: MIF, tPAI-1 and IL-1β were produced at higher levels in donor A blood relative to the other blood samples, whereas GM-CSF, TNF-α, IFN-γ, IL-7 and IL-10 remained at lower levels in donor A blood. Potential reasons for our observations are that the immune response of donor A significantly influenced the bacterial transcriptome, or both GBS gene expression and immune response were influenced by the metabolic status of donor A.
Collapse
|
15
|
Identification of Streptococcus agalactiae isolates from various phylogenetic lineages by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol 2009; 47:2284-7. [PMID: 19403759 DOI: 10.1128/jcm.00175-09] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Variations in proteins related to bacterial diversity may affect species identification performed using matrix-assisted laser desorption ionization (MALDI)-time of flight mass spectrometry. Using this method, we identified 110 Streptococcus agalactiae isolates characterized by serotyping and multilocus sequence typing. Serotype III and sequence type 23 strains expressed the widest variation in molecular weight of putative "species-identifying" biomarker ions. Recognition of the diversity of MALDI patterns observed in strains that represent all major intraspecies lineages assists in the constitution of an optimal reference database.
Collapse
|