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Dilrukshi N, Kottahachchi J, Dissanayake T, Weerasekera M, Sampath A, Fernando N. Unravelling Streptococcus agalactiae: Serotype distribution, virulence factors, obstetrics history and clinical presentation correlations in tertiary care hospitals of the western province of Sri Lanka. Indian J Med Microbiol 2024; 49:100617. [PMID: 38763381 DOI: 10.1016/j.ijmmb.2024.100617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 05/16/2024] [Accepted: 05/16/2024] [Indexed: 05/21/2024]
Abstract
PURPOSE This study investigated to detect serotypes and virulence genes of Group B Streptococcus (GBS) isolated from pregnant women. METHODS Forty-five samples of GBS isolates from January to August 2019 at antenatal clinics of 4 teaching hospitals in Western Province, Sri Lanka were included. Isolated GBS were carried to identify 9 serotypes by multiplex PCR. Different virulence determinants, including bac, rib and scp(B) have been detected by PCR. RESULTS Among GBS-positive culture isolates most abundant serotype detected was type III 12/45 (26.7%) while serotype VII, VIII and IX were not seen. Furthermore, serotype Ia (15.6%); II (20%); V (17.8%); VI (15.6%); Ib (2.2%) and IV (2.2%) were identified. Among 5 rectal isolates, 1 isolate was serotype Ia, 2 isolates were serotype II and 2 isolates were serotype III. Forty (40/45) isolates expressed scpB gene (88.8%). Presence of rib gene was confirmed in 17.8%, bac in 13.3% isolates. ScpB, rib and bac were identified in 4.4% isolates, 8.9% isolates were scpB, rib positive and bac negative, 8.9% isolates were scpB, bac positive and rib negative. These three-virulence genes did not express in 8.9% isolates. ScpB gene was found once in serotype Ib and IV and all serotype VI expressed scpB gene. Rib gene was more common among serotype II and it was not found in serotype Ib, IV and VI. Bac gene was more common in serotype V and it was not found in serotype Ia, Ib and IV. There was not significant association between serotypes and virulence gene (p > 0.05). CONCLUSION Serotype III is the most abundant serotype. In formulation of vaccine against GBS for Sri Lanka, serotype III should be targeted. Prevalence of vaccine candidate virulence protein such as β antigens of the C protein (bac) and surface protein Rib (rib) genes were low in this study.
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Affiliation(s)
- Niluka Dilrukshi
- University of Sri Jayewardenepura, Faculty of Medical Sciences, Department of Microbiology, Nugegoda, Gangodawila, Sri Lanka; University of Sri Jayewardenepura, Faculty of Graduate Studies, Nugegoda, Gangodawila, Sri Lanka; Faculty of Health Sciences, Department of Medical Laboratory Sciences, The Open University, Sri Lanka.
| | - Jananie Kottahachchi
- University of Sri Jayewardenepura, Faculty of Medical Sciences, Department of Microbiology, Nugegoda, Gangodawila, Sri Lanka.
| | - Thushari Dissanayake
- University of Sri Jayewardenepura, Faculty of Medical Sciences, Department of Microbiology, Nugegoda, Gangodawila, Sri Lanka.
| | - Manjula Weerasekera
- University of Sri Jayewardenepura, Faculty of Medical Sciences, Department of Microbiology, Nugegoda, Gangodawila, Sri Lanka.
| | - Asanga Sampath
- University of Sri Jayewardenepura, Faculty of Medical Sciences, Department of Microbiology, Nugegoda, Gangodawila, Sri Lanka.
| | - Neluka Fernando
- University of Sri Jayewardenepura, Faculty of Medical Sciences, Department of Microbiology, Nugegoda, Gangodawila, Sri Lanka.
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2
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Huang J, Dai X, Wu Z, Hu X, Sun J, Tang Y, Zhang W, Han P, Zhao J, Liu G, Wang X, Mao S, Wang Y, Call DR, Liu J, Wang L. Conjugative transfer of streptococcal prophages harboring antibiotic resistance and virulence genes. THE ISME JOURNAL 2023; 17:1467-1481. [PMID: 37369704 PMCID: PMC10432423 DOI: 10.1038/s41396-023-01463-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 06/06/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023]
Abstract
Prophages play important roles in the transduction of various functional traits, including virulence factors, but remain debatable in harboring and transmitting antimicrobial resistance genes (ARGs). Herein we characterize a prevalent family of prophages in Streptococcus, designated SMphages, which harbor twenty-five ARGs that collectively confer resistance to ten antimicrobial classes, including vanG-type vancomycin resistance locus and oxazolidinone resistance gene optrA. SMphages integrate into four chromosome attachment sites by utilizing three types of integration modules and undergo excision in response to phage induction. Moreover, we characterize four subtypes of Alp-related surface proteins within SMphages, the lethal effects of which are extensively validated in cell and animal models. SMphages transfer via high-frequency conjugation that is facilitated by integrative and conjugative elements from either donors or recipients. Our findings explain the widespread of SMphages and the rapid dissemination of ARGs observed in members of the Streptococcus genus.
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Affiliation(s)
- Jinhu Huang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xingyang Dai
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zuowei Wu
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Xiao Hu
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Junjie Sun
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yijun Tang
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wanqiu Zhang
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peizhao Han
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiaqi Zhao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guangjin Liu
- Key Lab of Animal Bacteriology, Ministry of Agriculture, OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiaoming Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shengyong Mao
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yang Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Douglas R Call
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, 99164, USA
| | - Jinxin Liu
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Liping Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
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Gonzalez-Miro M, Pawlowski A, Lehtonen J, Cao D, Larsson S, Darsley M, Kitson G, Fischer PB, Johansson-Lindbom B. Safety and immunogenicity of the group B streptococcus vaccine AlpN in a placebo-controlled double-blind phase 1 trial. iScience 2023; 26:106261. [PMID: 36915681 PMCID: PMC10005905 DOI: 10.1016/j.isci.2023.106261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/28/2022] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
Group B streptococcus (GBS) is a leading cause of life-threatening neonatal infections and subsets of adverse pregnancy outcomes. Essentially all GBS strains possess one allele of the alpha-like protein (Alp) family. A maternal GBS vaccine, consisting of the fused N-terminal domains of the Alps αC and Rib (GBS-NN), was recently demonstrated to be safe and immunogenic in healthy adult women. To enhance antibody responses to all clinically relevant Alps, a second-generation vaccine has been developed (AlpN), also containing the N-terminal domain of Alp1 and the one shared by Alp2 and Alp3. In this study, the safety and immunogenicity of AlpN is assessed in a randomized, double-blind, placebo-controlled, and parallel-group phase I study, involving 60 healthy non-pregnant women. AlpN is well tolerated and elicits similarly robust and persistent antibody responses against all four Alp-N-terminal domains, resulting in enhanced opsonophagocytic killing of all Alp serotypes covered by the vaccine.
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Affiliation(s)
| | | | - Janne Lehtonen
- Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
| | - Duojia Cao
- Immunology Section, Lund University, BMC D14, Lund, Sweden
| | - Sara Larsson
- Immunology Section, Lund University, BMC D14, Lund, Sweden
| | | | - Geoff Kitson
- Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
| | - Per B Fischer
- Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
| | - Bengt Johansson-Lindbom
- Immunology Section, Lund University, BMC D14, Lund, Sweden.,Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
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Dangor Z, Kwatra G, Pawlowski A, Fisher PB, Izu A, Lala SG, Johansson-Lindbom B, Madhi SA. Association of infant Rib and Alp1 surface protein N-terminal domain immunoglobulin G and invasive Group B Streptococcal disease in young infants. Vaccine 2023; 41:1679-1683. [PMID: 36754766 PMCID: PMC9996286 DOI: 10.1016/j.vaccine.2023.01.071] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 02/09/2023]
Abstract
BACKGROUND Vaccine development for Group B Streptococcus (GBS), a common cause of invasive disease in early-infancy and adverse pregnancy outcomes, include exploring widely-expressed GBS surface proteins as vaccine epitopes. We investigated the association between natural infant serum IgG against the RibN and Alp1N domains and risk of invasive GBS disease caused by isolates expressing these proteins. METHODS We analyzed maternal and infant serum samples from GBS disease cases and infants born to GBS-colonized women controls. Bayesian modelling was used to calculate the GBS homotypic IgG concentration associated with risk reduction of invasive disease in the infant. RESULTS PCR-based typing of 85 GBS invasive isolates showed 46 and 24 possessing the gene for Rib and Alp1, respectively. These were matched to 46 and 36 infant controls whose mothers were colonized with GBS expressing Rib and Alp1, respectively. RibN IgG geometric mean concentrations (GMC) were lower in cases than controls among infants (0.01; 95 %CI: 0.01-0.02 vs 0.04; 95 %CI: 0.03-0.06; p < 0.001), no significant difference was found between maternal RibN IgG GMC in cases compared to controls. Alp1N IgG GMC was also lower in infant cases (0.02; 95 %CI: 0.01-0.03) than controls (0.05; 95 %CI: 0.04-0.07; p < 0.001); albeit not so in mothers. An infant IgG threshold ≥ 0.428 and ≥ 0.112 µg/mL was associated with 90 % risk reduction of invasive GBS disease due to Rib and Alp1 expressing strains, respectively. DISCUSSION Lower serum RibN and Alp1N IgG GMC were evident in infants with invasive GBS disease compared with controls born to women colonized with GBS expressing the homotypic protein. These data support the evaluation of Alp family proteins as potential vaccine candidates against invasive GBS disease.
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Affiliation(s)
- Ziyaad Dangor
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Unit, University of the Witwatersrand, South Africa; Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
| | - Gaurav Kwatra
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Unit, University of the Witwatersrand, South Africa; Department of Clinical Microbiology, Christian Medical College, Vellore, India
| | | | | | - Alane Izu
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Unit, University of the Witwatersrand, South Africa
| | - Sanjay G Lala
- Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - Bengt Johansson-Lindbom
- Immunology Section, BMC D14, Lund University, Lund, Sweden; MinervaX ApS, DK-2200 Copenhagen N, Denmark
| | - Shabir A Madhi
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Unit, University of the Witwatersrand, South Africa; African Leadership in Vaccinology Expertise University of the Witwatersrand, South Africa.
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5
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Molecular Epidemiology of Group B Streptococcus Colonization in Egyptian Women. Microorganisms 2022; 11:microorganisms11010038. [PMID: 36677330 PMCID: PMC9861799 DOI: 10.3390/microorganisms11010038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/25/2022] Open
Abstract
(1) Background: Streptococcus agalactiae or Group B Streptococcus (GBS) causes severe neonatal infections with a high burden of disease, especially in Africa. Maternal vaginal colonization and perinatal transmissions represent the common mode of acquiring the infection. Development of an effective maternal vaccine against GBS relies on molecular surveillance of the maternal GBS population to better understand the global distribution of GBS clones and serotypes. (2) Methods: Here, we present genomic data from a collection of colonizing GBS strains from Ismailia, Egypt that were sequenced and characterized within the global JUNO project. (3) Results: A large proportion of serotype VI, ST14 strains was discovered, a serotype which is rarely found in strain collections from the US and Europe and typically not included in the current vaccine formulations. (4) Conclusions: The molecular epidemiology of these strains clearly points to the African origin with the detection of several sequence types (STs) that have only been observed in Africa. Our data underline the importance of continuous molecular surveillance of the GBS population for future vaccine implementations.
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6
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Basson A, Olaisen C, Selvik LK, Lyng RV, Lysvand H, Gidon A, Aas CG, Afset JE, Dragset MS. The Streptococcus agalactiae R3 surface protein is encoded by sar5. PLoS One 2022; 17:e0263199. [PMID: 35905090 PMCID: PMC9337641 DOI: 10.1371/journal.pone.0263199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 05/31/2022] [Indexed: 11/29/2022] Open
Abstract
Streptococcus agalactiae (group B streptococcus; GBS) is an important human pathogen causing pneumonia, sepsis and meningitis in neonates, as well as infections in pregnant women, immunocompromised individuals, and the elderly. For the future control of GBS-inflicted disease, GBS surface exposed proteins are particularly relevant as they may act as antigens for vaccine development and/or as serosubtype markers in epidemiological settings. Even so, the genes encoding some of the surface proteins established as serosubtype markers by antibody-based methods, like the R3 surface protein, are still unknown. Here, by examining a Norwegian GBS collection consisting of 140 strains, we find that R3 protein expression correlates with the presence of the gene sar5. By inducible expression of sar5 in an R3-negative bacterial strain we show that the sar5 gene product is specifically recognized by an R3 monoclonal antibody. With this we identify sar5 as the gene encoding the R3 surface protein, a serosubtype marker of hitherto unknown genetic origin.
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Affiliation(s)
- Adelle Basson
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Camilla Olaisen
- Department of Medical Microbiology, St. Olavs University Hospital, Trondheim, Norway
| | - Linn-Karina Selvik
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Centre for Molecular Inflammation Research (CEMIR), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Randi Valsø Lyng
- Department of Medical Microbiology, St. Olavs University Hospital, Trondheim, Norway
| | - Hilde Lysvand
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Alexandre Gidon
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Centre for Molecular Inflammation Research (CEMIR), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Christina Gabrielsen Aas
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Medical Microbiology, St. Olavs University Hospital, Trondheim, Norway
| | - Jan Egil Afset
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Medical Microbiology, St. Olavs University Hospital, Trondheim, Norway
| | - Marte Singsås Dragset
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Centre for Molecular Inflammation Research (CEMIR), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- * E-mail:
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7
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Khan UB, Jauneikaite E, Andrews R, Chalker VJ, Spiller OB. Identifying large-scale recombination and capsular switching events in Streptococcus agalactiae strains causing disease in adults in the UK between 2014 and 2015. Microb Genom 2022; 8:000783. [PMID: 35290175 PMCID: PMC9176283 DOI: 10.1099/mgen.0.000783] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cases of invasive group B streptococcal infection in the adult UK population have steadily increased over recent years, with the most common serotypes being V, III and Ia, but less is known of the genetic background of these strains. We have carried out in-depth analysis of the whole-genome sequences of 193 clinically important group B Streptococcus (GBS) isolates (184 were from invasive infection, 8 were from non-invasive infection and 1 had no information on isolation site) isolated from adults and submitted to the National Reference Laboratory at the UK Health Security Agency between January 2014 and December 2015. We have determined that capsular serotypes III (26.9%), Ia (26.4%) and V (15.0%) were most commonly identified, with slight differences in gender and age distribution. Most isolates (n=182) grouped to five clonal complexes (CCs), CC1, CC8/CC10, CC17, CC19 and CC23, with common associations between specific serotypes and virulence genes. Additionally, we have identified large recombination events mediating potential capsular switching events between sequence type (ST)1 serotype V and serotypes Ib (n=2 isolates), II (n=2 isolates) and VI (n=2 isolates); between ST19 serotype III and serotype V (n=5 isolates); and between CC17 serotype III and serotype IV (n=1 isolate). The high genetic diversity of disease-causing isolates and multiple recombination events reported in this study highlight the need for routine surveillance of the circulating disease-causing GBS strains. This information is crucial to better understand the global spread of GBS serotypes and genotypes, and will form the baseline information for any future GBS vaccine research in the UK and worldwide.
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Affiliation(s)
- Uzma Basit Khan
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK
- Present address: Parasites and Microbes, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK
| | - Elita Jauneikaite
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- *Correspondence: Elita Jauneikaite,
| | - Robert Andrews
- Systems Immunity University Research Institute, Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK
| | - Victoria J. Chalker
- National Infection Service, United Kingdom Health Security Agency, Colindale, London, UK
| | - Owen B. Spiller
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK
- National Infection Service, United Kingdom Health Security Agency, Colindale, London, UK
- *Correspondence: Owen B. Spiller,
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8
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Pawlowski A, Lannergård J, Gonzalez-Miro M, Cao D, Larsson S, Persson JJ, Kitson G, Darsley M, Rom AL, Hedegaard M, Fischer PB, Johansson-Lindbom B. A group B Streptococcus alpha-like protein subunit vaccine induces functionally active antibodies in humans targeting homotypic and heterotypic strains. Cell Rep Med 2022; 3:100511. [PMID: 35243418 PMCID: PMC8861819 DOI: 10.1016/j.xcrm.2022.100511] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/17/2021] [Accepted: 01/07/2022] [Indexed: 11/18/2022]
Abstract
Maternal vaccination is a promising strategy for preventing neonatal disease caused by group B Streptococcus. The safety and immunogenicity of the prototype vaccine GBS-NN, a fusion protein consisting of the N-terminal domains of the alpha-like proteins (Alp) αC and Rib, were recently evaluated favorably in healthy adult women in a phase 1 trial. Here we demonstrate robust immunoglobulin G (IgG) and immunoglobulin A (IgA) responses against αC and Rib, as well as against the heterotypic Alp family members Alp1–Alp3. IgA and heterotypic IgG responses are more variable between subjects and correlate with pre-existing immunity. Vaccine-induced IgG mediates opsonophagocytic killing and prevents bacterial invasion of epithelial cells. Like the vaccine-induced response, naturally acquired IgG against the vaccine domains is dominated by IgG1. Consistent with the high IgG1 cross-placental transfer rate, naturally acquired IgG against both domains reaches higher concentrations in neonatal than maternal blood, as assessed in a separate group of non-vaccinated pregnant women and their babies. GBS-NN subunit vaccine broadly elicits IgG1 to homotypic αC and Rib N-terminal domains IgA and heterotypic IgG responses occur in vaccinees with pre-existing immunity Abs mediate opsonophagocytic killing and prevent bacterial epithelial cell invasion IgG against αC-N and Rib-N is transferred efficiently across the placenta
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Affiliation(s)
| | - Jonas Lannergård
- Immunology Section, BMC D14, Lund University, 221 84 Lund, Sweden
| | | | - Duojia Cao
- Immunology Section, BMC D14, Lund University, 221 84 Lund, Sweden
| | - Sara Larsson
- Immunology Section, BMC D14, Lund University, 221 84 Lund, Sweden
| | - Jenny J Persson
- Immunology Section, BMC D14, Lund University, 221 84 Lund, Sweden
| | - Geoff Kitson
- Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
| | | | - Ane Lilleøre Rom
- Department of Obstetrics, the Juliane Marie Centre, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark.,The Research Unit for Women's and Children's Health, the Juliane Marie Centre, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Morten Hedegaard
- Department of Obstetrics, the Juliane Marie Centre, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Per B Fischer
- Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
| | - Bengt Johansson-Lindbom
- Immunology Section, BMC D14, Lund University, 221 84 Lund, Sweden.,Minervax A/S, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark
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9
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Barros RR, Alves KB, Luiz FBO, Ferreira DG. Prevalence of Streptococcus agalactiae capsular types among pregnant women in Rio de Janeiro and the impact of a capsular based vaccine. BRAZ J PHARM SCI 2022. [DOI: 10.1590/s2175-979020222e20633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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10
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Dobrut A, Brzychczy-Włoch M. Immunogenic Proteins of Group B Streptococcus-Potential Antigens in Immunodiagnostic Assay for GBS Detection. Pathogens 2021; 11:43. [PMID: 35055991 PMCID: PMC8778278 DOI: 10.3390/pathogens11010043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/29/2021] [Accepted: 12/29/2021] [Indexed: 12/21/2022] Open
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is an opportunistic pathogen, which asymptomatically colonizes the gastrointestinal and genitourinary tract of up to one third of healthy adults. Nevertheless, GBS carriage in pregnant women may lead to several health issues in newborns causing life threatening infection, such as sepsis, pneumonia or meningitis. Recommended GBS screening in pregnant women significantly reduced morbidity and mortality in infants. Nevertheless, intrapartum antibiotic prophylaxis, recommended following the detection of carriage or in case of lack of a carriage test result for pregnant women who demonstrate certain risk factors, led to the expansion of the adverse phenomenon of bacterial resistance to antibiotics. In our paper, we reviewed some immunogenic GBS proteins, i.e., Alp family proteins, β protein, Lmb, Sip, BibA, FsbA, ScpB, enolase, elongation factor Tu, IMPDH, and GroEL, which possess features characteristic of good candidates for immunodiagnostic assays for GBS carriage detection, such as immunoreactivity and specificity. We assume that they can be used as an alternative diagnostic method to the presently recommended bacteriological cultivation and MALDI.
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Affiliation(s)
| | - Monika Brzychczy-Włoch
- Department of Molecular Medical Microbiology, Faculty of Medicine, Medical College, Jagiellonian University, 31-121 Krakow, Poland;
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11
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Ferreira MNMR, de Paula GR, Barros RR. Distribution of virulence determinants in Streptococcus agalactiae recovered from different clinical sources. Microb Pathog 2021; 161:105255. [PMID: 34678459 DOI: 10.1016/j.micpath.2021.105255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 11/25/2022]
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) is a pathobiont, a member of human microbiota that can change from commensal to pathogen, causing a large spectrum of diseases. This study assessed virulence determinants of 32 GBS isolates recovered from different clinical sources associated with asymptomatic and symptomatic clinical outcomes that present distinct capsular types and antimicrobial resistance profiles. The ability of a unique strain to colonize and cause infection in different subjects was also evaluated. By PFGE analysis, it was observed that a given strain could be associated with both asymptomatic and symptomatic outcomes. Cell wall anchor proteins β and alpha C encoding genes (bac and bca, respectively) were detected in all capsular type Ib isolates. bca was more frequent among asymptomatic outcome-related isolates, as well as high expression of β-hemolysin/cytolysin (β-H/C). Symptomatic outcome-related isolates produced strong biofilm more frequently. All bacterial isolates recovered from urine were strong biofilm producers. In growth experiments, asymptomatic outcome-related isolates grew faster after 2 h until the end of the log phase. Taken together, these findings show virulence genotypic and phenotypic features of GBS from distinct sources, which may be helpful to understand their pathogenic potential and predict different clinical outcomes.
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Affiliation(s)
- Mariana Nunes M R Ferreira
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Brazil
| | - Geraldo Renato de Paula
- Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal Fluminense, Brazil
| | - Rosana Rocha Barros
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Brazil.
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12
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C-protein α-antigen modulates the lantibiotic thusin resistance in Streptococcus agalactiae. Antonie van Leeuwenhoek 2021; 114:1595-1607. [PMID: 34319449 DOI: 10.1007/s10482-021-01626-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 07/19/2021] [Indexed: 10/20/2022]
Abstract
Screening for producers of potent antimicrobial peptides, resulted in the isolation of Bacillus cereus BGNM1 with strong antimicrobial activity against Listeria monocytogenes. Genome sequence analysis revealed that BGNM1 contains the gene cluster associated with the production of the lantibiotic, thusin, previously identified in B. thuringiensis. Purification of the antimicrobial activity confirmed that strain BGMN1 produces thusin. Both thusin sensitive and resistant strains were detected among clinical isolates of Streptococcus agalactiae. Random mutagenesis of a thusin sensitive strain, S. agalactiae B782, was performed in an attempt to identify the receptor protein for thusin. Three independent thusin resistant mutants were selected and their complete genomes sequenced. Comparative sequence analysis of these mutants with the WT strain revealed that duplication of a region encoding a 79 amino acids repeat in a C-protein α-antigen was a common difference, suggesting it to be responsible for increased resistance to thusin. Since induced thusin resistant mutants showed higher level of resistance than the naturally resistant B761 strain, complete genome sequencing of strain B761 was performed to check the integrity of the C-protein α-antigen-encoding gene. This analysis revealed that this gene is deleted in B761, providing further evidence that this protein promotes interaction of the thusin with receptor.
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13
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Safety and immunogenicity of a prototype recombinant alpha-like protein subunit vaccine (GBS-NN) against Group B Streptococcus in a randomised placebo-controlled double-blind phase 1 trial in healthy adult women. Vaccine 2021; 39:4489-4499. [PMID: 34215454 DOI: 10.1016/j.vaccine.2021.06.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/24/2021] [Accepted: 06/18/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND Group B Streptococcus (GBS) is the leading cause of life-threatening infections in new-borns and may cause invasive disease, stillbirth and preterm delivery during pregnancy. While no licensed vaccine exists, maternal immunization might protect against neonatal disease and adverse pregnancy outcomes. We assessed the safety and immunogenicity of a prototype vaccine consisting of the fused N-terminal domains of the AlphaC and Rib surface proteins of GBS (GBS-NN). METHODS GBS-NN was tested in a randomised, double-blind, placebo-controlled, parallel group, phase I study, in healthy non-pregnant women. A dose-escalation phase, with two doses, four weeks apart, of 10, 50 or 250 µg, administered with or without aluminium hydroxide, was initially assessed (n = 60). This was followed by a dose-confirmation study, where one dose of 100 µg adjuvanted GBS-NN was compared with two doses of either 50 or 100 µg adjuvanted GBS-NN, again administered with four weeks interval between the doses (n = 180). Safety and immunogenicity were monitored for one year. RESULTS GBS-NN was well tolerated with some, mostly mild, injection site reactions observed. Adjuvant significantly increased antibody concentrations and the response was boosted by a second dose. The IgG GMCs remained strongly elevated during the whole one-year duration of the study. Maximal responses occurred after two 50 µg doses, resulting in IgG GMC of 16.9 µg/ml at the primary immunological endpoint, twelve weeks after the first dose. For this regimen, 100% and 89% of the subjects achieved antibody levels above the arbitrary thresholds of 1 and 4 µg/ml, respectively. The added beneficial effect of a second dose was most pronounced for subjects with pre-existing IgG levels below the median of the entire cohort. CONCLUSION The prototype GBS-NN vaccine was found to be well tolerated and highly immunogenic with an optimal regimen of two doses of 50 µg in the presence of adjuvant. Further development of a maternal vaccine based on the N-terminal domains of the alpha-like protein family of GBS is warranted (NCT02459262).
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14
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McGee L, Chochua S, Li Z, Mathis S, Rivers J, Metcalf B, Ryan A, Alden N, Farley MM, Harrison LH, Snippes Vagnone P, Lynfield R, Smelser C, Muse A, Thomas AR, Schrag S, Beall BW. Multistate, Population-Based Distributions of Candidate Vaccine Targets, Clonal Complexes, and Resistance Features of Invasive Group B Streptococci Within the United States, 2015-2017. Clin Infect Dis 2021; 72:1004-1013. [PMID: 32060499 DOI: 10.1093/cid/ciaa151] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/13/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis and an important cause of invasive infections in pregnant and nonpregnant adults. Vaccines targeting capsule polysaccharides and common proteins are under development. METHODS Using whole genome sequencing, a validated bioinformatics pipeline, and targeted antimicrobial susceptibility testing, we characterized 6340 invasive GBS isolates recovered during 2015-2017 through population-based Active Bacterial Core surveillance (ABCs) in 8 states. RESULTS Six serotypes accounted for 98.4% of isolates (21.8% Ia, 17.6% V, 17.1% II, 15.6% III, 14.5% Ib, 11.8% IV). Most (94.2%) isolates were in 11 clonal complexes (CCs) comprised of multilocus sequence types identical or closely related to sequence types 1, 8, 12, 17, 19, 22, 23, 28, 88, 452, and 459. Fifty-four isolates (0.87%) had point mutations within pbp2x associated with nonsusceptibility to 1 or more β-lactam antibiotics. Genes conferring resistance to macrolides and/or lincosamides were found in 56% of isolates; 85.2% of isolates had tetracycline resistance genes. Two isolates carrying vanG were vancomycin nonsusceptible (minimum inhibitory concentration = 2 µg/mL). Nearly all isolates possessed capsule genes, 1-2 of the 3 main pilus gene clusters, and 1 of 4 homologous alpha/Rib family determinants. Presence of the hvgA virulence gene was primarily restricted to serotype III/CC17 isolates (465 isolates), but 8 exceptions (7 IV/CC452 and 1 IV/CC17) were observed. CONCLUSIONS This first comprehensive, population-based quantitation of strain features in the United States suggests that current vaccine candidates should have good coverage. The β-lactams remain appropriate for first-line treatment and prophylaxis, but emergence of nonsusceptibility warrants ongoing monitoring.
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Affiliation(s)
- Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sopio Chochua
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Zhongya Li
- IHRC Inc, Contractor to Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Saundra Mathis
- IHRC Inc, Contractor to Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Joy Rivers
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Benjamin Metcalf
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Alison Ryan
- California Emerging Infections Program, Oakland, California, USA
| | - Nisha Alden
- Colorado Department of Public Health and Environment, Denver, Colorado, USA
| | - Monica M Farley
- Emory University School of Medicine, Atlanta, Georgia, USA.,Atlanta Veterans Affairs Medical Center, Atlanta, Georgia, USA
| | - Lee H Harrison
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | | | - Ruth Lynfield
- Minnesota Department of Health, Saint Paul, Minnesota, USA
| | - Chad Smelser
- New Mexico Department of Public Health, Santa Fe, New Mexico, USA
| | - Alison Muse
- New York State Department of Health, Albany, New York, USA
| | - Ann R Thomas
- Oregon Department of Human Services, Portland, Oregon, USA
| | - Stephanie Schrag
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Bernard W Beall
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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15
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Alderson MR, Welsch JA, Regan K, Newhouse L, Bhat N, Marfin AA. Vaccines to Prevent Meningitis: Historical Perspectives and Future Directions. Microorganisms 2021; 9:microorganisms9040771. [PMID: 33917003 PMCID: PMC8067733 DOI: 10.3390/microorganisms9040771] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 12/20/2022] Open
Abstract
Despite advances in the development and introduction of vaccines against the major bacterial causes of meningitis, the disease and its long-term after-effects remain a problem globally. The Global Roadmap to Defeat Meningitis by 2030 aims to accelerate progress through visionary and strategic goals that place a major emphasis on preventing meningitis via vaccination. Global vaccination against Haemophilus influenzae type B (Hib) is the most advanced, such that successful and low-cost combination vaccines incorporating Hib are broadly available. More affordable pneumococcal conjugate vaccines are becoming increasingly available, although countries ineligible for donor support still face access challenges and global serotype coverage is incomplete with existing licensed vaccines. Meningococcal disease control in Africa has progressed with the successful deployment of a low-cost serogroup A conjugate vaccine, but other serogroups still cause outbreaks in regions of the world where broadly protective and affordable vaccines have not been introduced into routine immunization programs. Progress has lagged for prevention of neonatal meningitis and although maternal vaccination against the leading cause, group B streptococcus (GBS), has progressed into clinical trials, no GBS vaccine has thus far reached Phase 3 evaluation. This article examines current and future efforts to control meningitis through vaccination.
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16
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Carreras-Abad C, Ramkhelawon L, Heath PT, Le Doare K. A Vaccine Against Group B Streptococcus: Recent Advances. Infect Drug Resist 2020; 13:1263-1272. [PMID: 32425562 PMCID: PMC7196769 DOI: 10.2147/idr.s203454] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/10/2020] [Indexed: 01/12/2023] Open
Abstract
Group B streptococcus (GBS) causes a high burden of neonatal and infant disease globally. Implementing a vaccine for pregnant women is a promising strategy to prevent neonatal and infant GBS disease and has been identified as a priority by the World Health Organisation (WHO). GBS serotype-specific polysaccharide – protein conjugate vaccines are at advanced stages of development, but a large number of participants would be required to undertake Phase III clinical efficacy trials. Efforts are therefore currently focused on establishing serocorrelates of protection in natural immunity studies as an alternative pathway for licensure of a GBS vaccine, followed by Phase IV studies to evaluate safety and effectiveness. Protein vaccines are in earlier stages of development but are highly promising as they might confer protection irrespective of serotype. Further epidemiological, immunological and health economic studies are required to enable the vaccine to reach its target population as soon as possible.
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Affiliation(s)
- Clara Carreras-Abad
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK.,Department of Paediatrics, Obstetrics and Gynecology and Preventive Medicine and Public Health, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laxmee Ramkhelawon
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Paul T Heath
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Kirsty Le Doare
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK.,Pathogen Immunity Group, Public Health England, Porton Down,UK.,Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine, Uganda Research Unit, Entebbe, Uganda
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17
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Eraso JM, Kachroo P, Olsen RJ, Beres SB, Zhu L, Badu T, Shannon S, Cantu CC, Saavedra MO, Kubiak SL, Porter AR, DeLeo FR, Musser JM. Genetic heterogeneity of the Spy1336/R28-Spy1337 virulence axis in Streptococcus pyogenes and effect on gene transcript levels and pathogenesis. PLoS One 2020; 15:e0229064. [PMID: 32214338 PMCID: PMC7098570 DOI: 10.1371/journal.pone.0229064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/28/2020] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pyogenes is a strict human pathogen responsible for more than 700 million infections annually worldwide. Strains of serotype M28 S. pyogenes are typically among the five more abundant types causing invasive infections and pharyngitis in adults and children. Type M28 strains also have an unusual propensity to cause puerperal sepsis and neonatal disease. We recently discovered that a one-nucleotide indel in an intergenic homopolymeric tract located between genes Spy1336/R28 and Spy1337 altered virulence in a mouse model of infection. In the present study, we analyzed size variation in this homopolymeric tract and determined the extent of heterogeneity in the number of tandemly-repeated 79-amino acid domains in the coding region of Spy1336/R28 in large samples of strains recovered from humans with invasive infections. Both repeat sequence elements are highly polymorphic in natural populations of M28 strains. Variation in the homopolymeric tract results in (i) changes in transcript levels of Spy1336/R28 and Spy1337 in vitro, (ii) differences in virulence in a mouse model of necrotizing myositis, and (iii) global transcriptome changes as shown by RNAseq analysis of isogenic mutant strains. Variation in the number of tandem repeats in the coding sequence of Spy1336/R28 is responsible for size variation of R28 protein in natural populations. Isogenic mutant strains in which genes encoding R28 or transcriptional regulator Spy1337 are inactivated are significantly less virulent in a nonhuman primate model of necrotizing myositis. Our findings provide impetus for additional studies addressing the role of R28 and Spy1337 variation in pathogen-host interactions.
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Affiliation(s)
- Jesus M. Eraso
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Priyanka Kachroo
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Randall J. Olsen
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
- Departments of Pathology and Laboratory Medicine and Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Stephen B. Beres
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Luchang Zhu
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Traci Badu
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Sydney Shannon
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Concepcion C. Cantu
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Matthew Ojeda Saavedra
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Samantha L. Kubiak
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
| | - Adeline R. Porter
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Frank R. DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - James M. Musser
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, United States of America
- Departments of Pathology and Laboratory Medicine and Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
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18
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Whelan F, Lafita A, Griffiths SC, Cooper REM, Whittingham JL, Turkenburg JP, Manfield IW, St. John AN, Paci E, Bateman A, Potts JR. Defining the remarkable structural malleability of a bacterial surface protein Rib domain implicated in infection. Proc Natl Acad Sci U S A 2019; 116:26540-26548. [PMID: 31818940 PMCID: PMC6936399 DOI: 10.1073/pnas.1911776116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Streptococcus groups A and B cause serious infections, including early onset sepsis and meningitis in newborns. Rib domain-containing surface proteins are found associated with invasive strains and elicit protective immunity in animal models. Yet, despite their apparent importance in infection, the structure of the Rib domain was previously unknown. Structures of single Rib domains of differing length reveal a rare case of domain atrophy through deletion of 2 core antiparallel strands, resulting in the loss of an entire sheet of the β-sandwich from an immunoglobulin-like fold. Previously, observed variation in the number of Rib domains within these bacterial cell wall-attached proteins has been suggested as a mechanism of immune evasion. Here, the structure of tandem domains, combined with molecular dynamics simulations and small angle X-ray scattering, suggests that variability in Rib domain number would result in differential projection of an N-terminal host-colonization domain from the bacterial surface. The identification of 2 further structures where the typical B-D-E immunoglobulin β-sheet is replaced with an α-helix further confirms the extensive structural malleability of the Rib domain.
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Affiliation(s)
- Fiona Whelan
- Department of Biology, The University of York, YO10 5DD York, United Kingdom
| | - Aleix Lafita
- European Molecular Biology Laboratory, European Bioinformatics Institute, CB10 1SD Hinxton, United Kingdom
| | - Samuel C. Griffiths
- Department of Biology, The University of York, YO10 5DD York, United Kingdom
| | | | - Jean L. Whittingham
- York Structural Biology Laboratory, Department of Chemistry, The University of York, YO10 5DD York, United Kingdom
| | - Johan P. Turkenburg
- York Structural Biology Laboratory, Department of Chemistry, The University of York, YO10 5DD York, United Kingdom
| | - Iain W. Manfield
- Astbury Centre for Structural Molecular Biology, The University of Leeds, LS2 9JT Leeds, United Kingdom
| | - Alexander N. St. John
- Astbury Centre for Structural Molecular Biology, The University of Leeds, LS2 9JT Leeds, United Kingdom
| | - Emanuele Paci
- Astbury Centre for Structural Molecular Biology, The University of Leeds, LS2 9JT Leeds, United Kingdom
| | - Alex Bateman
- European Molecular Biology Laboratory, European Bioinformatics Institute, CB10 1SD Hinxton, United Kingdom
| | - Jennifer R. Potts
- Department of Biology, The University of York, YO10 5DD York, United Kingdom
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19
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Song JY, Lim JH, Lim S, Yong Z, Seo HS. Progress toward a group B streptococcal vaccine. Hum Vaccin Immunother 2018; 14:2669-2681. [PMID: 29995578 PMCID: PMC6314413 DOI: 10.1080/21645515.2018.1493326] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/18/2018] [Accepted: 06/19/2018] [Indexed: 01/31/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of severe invasive disease in neonate, elderly, and immunocompromised patients worldwide. Despite recent advances in the diagnosis and intrapartum antibiotic prophylaxis (IAP) of GBS infections, it remains one of the most common causes of neonatal morbidity and mortality, causing serious infections. Furthermore, recent studies reported an increasing number of GBS infections in pregnant women and elderly. Although IAP is effective, it has several limitations, including increasing antimicrobial resistance and late GBS infection after negative antenatal screening. Maternal immunization is the most promising and effective countermeasure against GBS infection in neonates. However, no vaccine is available to date, but two types of vaccines, protein subunit and capsular polysaccharide conjugate vaccines, were investigated in clinical trials. Here, we provide an overview of the GBS vaccine development status and recent advances in the development of immunoassays to evaluate the GBS vaccine clinical efficacy.
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Affiliation(s)
- Joon Young Song
- Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jae Hyang Lim
- Department of Microbiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Sangyong Lim
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Zhi Yong
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Ho Seong Seo
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon, Republic of Korea
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20
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Rose F, Roovers S, Fano M, Harloff-Helleberg S, Kirkensgaard JJK, Hejnaes K, Fischer P, Foged C. Temperature-Induced Self-Assembly of the Group B Streptococcus (GBS) Fusion Antigen GBS-NN. Mol Pharm 2018; 15:2584-2593. [PMID: 29745668 DOI: 10.1021/acs.molpharmaceut.8b00101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Group B Streptococcus (GBS) is a leading cause of serious bacterial neonatal infections worldwide, which provides an unmet medical need for a globally effective vaccine. The recombinant GBS fusion antigen GBS-NN contains the N-terminal regions of the GBS Rib and Alpha C proteins. It shows promising immunogenicity eliciting protective immunity in mice and encouraging results in early human clinical trials. Understanding the physical stability of GBS-NN containing conformational B-cell epitopes is crucial to ensure optimal vaccine stability, efficacy, and safety. We initially discovered that GBS-NN is prone to form higher-order structures at elevated temperatures. We therefore investigated the self-assembly behavior of GBS-NN and characterized the higher-order conformational structures as a function of temperature. In the native state, GBS-NN exists as a monomer and has a secondary structure containing α-helix and β-sheet. Langmuir studies demonstrated that the native protein is highly surface-active and forms a monolayer film at the air-water interface because of its amphipathic properties. The conformational stability of GBS-NN was measured as a function of temperature. GBS-NN has an unusual thermal behavior with a phase transition of approximately 61 °C, which is not accompanied by any major changes in the secondary structure. However, the antigen showed irreversible self-assembly as a function of temperature into higher-order structures with a hydrodynamic diameter of approximately 100 nm. Cryo-transmission electron microscopy analyses demonstrated that these self-assemblies consist of vesicular, ring-like structures with a hollow aqueous interior. Therefore, GBS-NN is a physically stable monomeric protein but is prone to temperature-induced self-assembly above 61 °C.
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Affiliation(s)
| | - Silke Roovers
- Laboratory of General Biochemistry and Physical Pharmacy , Ghent University , Ottergemsesteenweg 460 , 9000 Ghent , Belgium
| | | | | | - Jacob J K Kirkensgaard
- Niels Bohr Institute, Faculty of Science , University of Copenhagen , Universitetsparken 5 , DK-2100 Copenhagen Ø , Denmark
| | - Kim Hejnaes
- MinervaX ApS , Ole Maaløes Vej 3 , DK-2200 Copenhagen N , Denmark
| | - Per Fischer
- MinervaX ApS , Ole Maaløes Vej 3 , DK-2200 Copenhagen N , Denmark
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21
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Nie S, Lu X, Jin Z, Gao J, Ma D, Deng J, Wu X, Hu YW, Zheng L, Wang Q. Characterization of group B Streptococcus isolated from sterile and non-sterile specimens in China. Diagn Microbiol Infect Dis 2018; 92:56-61. [PMID: 29858112 DOI: 10.1016/j.diagmicrobio.2018.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 04/29/2018] [Accepted: 04/30/2018] [Indexed: 11/20/2022]
Abstract
Group B streptococcus (GBS) is a leading cause of invasive neonatal infections and has increasingly been associated with invasive diseases in non-pregnant adults. We collected 113 GBS isolates recovered from sterile and non-sterile specimens from seven tertiary hospitals in China between October 2014 and September 2016. Medical records were retrospectively reviewed and the sequence types, serotypes, virulence, and antimicrobial resistance profiles of the isolates were characterized and correlated. Significantly higher C-reactive protein and procalcitonin levels and absolute neutrophil counts were observed in patients with invasive infections than in those with non-invasive infections (P < 0.05). The 113 isolates were grouped into 24 sequence types, 5 clonal complexes, and 6 serotypes. multivariate analysis revealed that clonal complex 17 isolates characterized by serotype iii, the surface protein gene rib, and the pilus island pi-2b were independently correlated with invasive infection (or: 6.79; 95% ci: 2.31-19.94, P < 0.001). These results suggest alternative molecular biomarkers for diagnosis and prognosis of GBS infections.
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Affiliation(s)
- Shuping Nie
- Department of Laboratory Medicine, The Eighth Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China; Laboratory Medicine Centre, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xuedong Lu
- Department of Laboratory Medicine, The Eighth Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| | - Zhengjiang Jin
- Department of Laboratory Medicine, Hubei Provincial Maternity & Child Healthcare Hospital,Wuhan, China
| | - Juyi Gao
- Department of Laboratory Medicine, The university of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Dongli Ma
- Department of Laboratory Medicine, Shenzhen Children's Hospital, Shenzhen, China
| | - Jikui Deng
- Department of Infectious Disease, Shenzhen Children's Hospital, Shenzhen, China
| | - Xianglin Wu
- Department of Laboratory Medicine, Shenzhen Guangming New District People's Hospital, Shenzhen, China
| | - Yan-Wei Hu
- Laboratory Medicine Centre, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lei Zheng
- Laboratory Medicine Centre, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qian Wang
- Laboratory Medicine Centre, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Pietrocola G, Arciola CR, Rindi S, Montanaro L, Speziale P. Streptococcus agalactiae Non-Pilus, Cell Wall-Anchored Proteins: Involvement in Colonization and Pathogenesis and Potential as Vaccine Candidates. Front Immunol 2018; 9:602. [PMID: 29686667 PMCID: PMC5900788 DOI: 10.3389/fimmu.2018.00602] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/09/2018] [Indexed: 11/13/2022] Open
Abstract
Group B Streptococcus (GBS) remains an important etiological agent of several infectious diseases including neonatal septicemia, pneumonia, meningitis, and orthopedic device infections. This pathogenicity is due to a variety of virulence factors expressed by Streptococcus agalactiae. Single virulence factors are not sufficient to provoke a streptococcal infection, which is instead promoted by the coordinated activity of several pathogenicity factors. Such determinants, mostly cell wall-associated and secreted proteins, include adhesins that mediate binding of the pathogen to host extracellular matrix/plasma ligands and cell surfaces, proteins that cooperate in the invasion of and survival within host cells and factors that neutralize phagocytosis and/or modulate the immune response. The genome-based approaches and bioinformatics tools and the extensive use of biophysical and biochemical methods and animal model studies have provided a great wealth of information on the molecular structure and function of these virulence factors. In fact, a number of new GBS surface-exposed or secreted proteins have been identified (GBS immunogenic bacterial adhesion protein, leucine-rich repeat of GBS, serine-rich repeat proteins), the three-dimensional structures of known streptococcal proteins (αC protein, C5a peptidase) have been solved and an understanding of the pathogenetic role of "old" and new determinants has been better defined in recent years. Herein, we provide an update of our current understanding of the major surface cell wall-anchored proteins from GBS, with emphasis on their biochemical and structural properties and the pathogenetic roles they may have in the onset and progression of host infection. We also focus on the antigenic profile of these compounds and discuss them as targets for therapeutic intervention.
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Affiliation(s)
- Giampiero Pietrocola
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Bologna, Italy.,Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Simonetta Rindi
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Lucio Montanaro
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Bologna, Italy.,Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Pietro Speziale
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Department of Industrial and Information Engineering, University of Pavia, Pavia, Italy
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23
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Population structure and virulence gene profiles of Streptococcus agalactiae collected from different hosts worldwide. Eur J Clin Microbiol Infect Dis 2017; 37:527-536. [PMID: 29181634 DOI: 10.1007/s10096-017-3146-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 11/14/2017] [Indexed: 01/25/2023]
Abstract
Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373 S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains were identified that were spread across different continents and/or were present in more than one host species. In particular, several strains were detected in both humans and cattle, and several canine strains were also detected in samples from human, bovine, and porcine hosts. The findings of our study suggest that although S. agalactiae is well adapted to various hosts including humans, cattle, dogs, rodents, and fish, interspecies transmission is possible and occurs between humans and cows, dogs, and rabbits. The virulence and resistance gene profiles presented enable new insights into interspecies transmission and make a crucial contribution to the identification of suitable targets for therapeutic agents and vaccines.
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24
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Durante IM, La Spina PE, Carmona SJ, Agüero F, Buscaglia CA. High-resolution profiling of linear B-cell epitopes from mucin-associated surface proteins (MASPs) of Trypanosoma cruzi during human infections. PLoS Negl Trop Dis 2017; 11:e0005986. [PMID: 28961244 PMCID: PMC5636173 DOI: 10.1371/journal.pntd.0005986] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/11/2017] [Accepted: 09/21/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The Trypanosoma cruzi genome bears a huge family of genes and pseudogenes coding for Mucin-Associated Surface Proteins (MASPs). MASP molecules display a 'mosaic' structure, with highly conserved flanking regions and a strikingly variable central and mature domain made up of different combinations of a large repertoire of short sequence motifs. MASP molecules are highly expressed in mammal-dwelling stages of T. cruzi and may be involved in parasite-host interactions and/or in diverting the immune response. METHODS/PRINCIPLE FINDINGS High-density microarrays composed of fully overlapped 15mer peptides spanning the entire sequences of 232 non-redundant MASPs (~25% of the total MASP content) were screened with chronic Chagasic sera. This strategy led to the identification of 86 antigenic motifs, each one likely representing a single linear B-cell epitope, which were mapped to 69 different MASPs. These motifs could be further grouped into 31 clusters of structurally- and likely antigenically-related sequences, and fully characterized. In contrast to previous reports, we show that MASP antigenic motifs are restricted to the central and mature region of MASP polypeptides, consistent with their intracellular processing. The antigenicity of these motifs displayed significant positive correlation with their genome dosage and their relative position within the MASP polypeptide. In addition, we verified the biased genetic co-occurrence of certain antigenic motifs within MASP polypeptides, compatible with proposed intra-family recombination events underlying the evolution of their coding genes. Sequences spanning 7 MASP antigenic motifs were further evaluated using distinct synthesis/display approaches and a large panel of serum samples. Overall, the serological recognition of MASP antigenic motifs exhibited a remarkable non normal distribution among the T. cruzi seropositive population, thus reducing their applicability in conventional serodiagnosis. As previously observed in in vitro and animal infection models, immune signatures supported the concurrent expression of several MASPs during human infection. CONCLUSIONS/SIGNIFICANCE In spite of their conspicuous expression and potential roles in parasite biology, this study constitutes the first unbiased, high-resolution profiling of linear B-cell epitopes from T. cruzi MASPs during human infection.
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Affiliation(s)
- Ignacio M. Durante
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Buenos Aires, Argentina
| | - Pablo E. La Spina
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Buenos Aires, Argentina
| | - Santiago J. Carmona
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Buenos Aires, Argentina
| | - Fernán Agüero
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Buenos Aires, Argentina
- * E-mail: (FA); (CAB)
| | - Carlos A. Buscaglia
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Buenos Aires, Argentina
- * E-mail: (FA); (CAB)
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25
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Gabrielsen C, Mæland JA, Lyng RV, Radtke A, Afset JE. Molecular characteristics of Streptococcus agalactiae strains deficient in alpha-like protein encoding genes. J Med Microbiol 2017; 66:26-33. [PMID: 28032541 DOI: 10.1099/jmm.0.000412] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Streptococcus agalactiae (group B streptococci, GBS) are important human and animal pathogens, which can be subdivided based on different capsular polysaccharides and surface-anchored alpha-like proteins (Alps), as well as other proteins. Nearly all GBS strains possess an Alp (Alp GBS), although Alp-negative GBS (non-Alp GBS) do occur. In this study, 10 (1.1 %) of 932 clinical human GBS tested lacked an Alp encoding gene. All 10 strains were from patients with bloodstream infection, confirming that non-Alp GBS can be highly virulent. All non-Alp GBS expressed one or more of the surface-anchored proteins R3, Z1 and Z2, while less than 10 % of unselected clinical strains express any of these proteins. In contrast to Alp GBS, all non-Alp strains tested were PCR negative for the upstream sequence of the insertion site of the Alp encoding gene of Alp GBS. Genome sequencing showed that all but one of the 10 clinical non-Alp strains and the non-Alp reference strain CNCTC 10/84 lacked a region surrounding the Alp gene commonly present in Alp GBS strains. These strains instead harboured an 849 bp region not present in the Cα prototype strain A909. We have shown that non-Alp GBS differ from Alp GBS in the region surrounding the insertion site of Alp genes of Alp GBS as well as in their content of other surface proteins and that PCR for the upstream flanking region of the Alp gene may be useful for differentiation between Alp and non-Alp GBS.
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Affiliation(s)
- Christina Gabrielsen
- Department of Medical Microbiology, St Olavs University Hospital, Trondheim, Norway
| | - Johan A Mæland
- Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Randi Valsø Lyng
- Department of Medical Microbiology, St Olavs University Hospital, Trondheim, Norway
| | - Andreas Radtke
- Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Medical Microbiology, St Olavs University Hospital, Trondheim, Norway
| | - Jan Egil Afset
- Department of Medical Microbiology, St Olavs University Hospital, Trondheim, Norway.,Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
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26
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Molecular characteristics and antimicrobial resistance in invasive and noninvasive Group B Streptococcus between 2008 and 2015 in China. Diagn Microbiol Infect Dis 2016; 86:351-357. [PMID: 27692802 DOI: 10.1016/j.diagmicrobio.2016.08.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/19/2016] [Accepted: 08/24/2016] [Indexed: 01/28/2023]
Abstract
Group B streptococcus (GBS) is an increasing pathogen threat to newborns and adults with immunodepressive diseases. Here, a total of 193 GBS, including 51 invasive and 142 noninvasive isolates, were collected from the patients with infections in 7 tertiary hospitals from 5 cities in China during the year 2008 to 2015. The strains of GBS were characterized by classical and molecular techniques for capsular polysaccharide serotyping, genes for pilus island (PI) and α-like protein (alp), and antibiotic resistance profiling. Of 193 isolates, the predominant serotypes were III (45.6%) and Ia (18.7%). All strains carried at least 1 PI gene. The combination of PI-2b and PI-1 was present in 46.1% isolates, followed by PI-2a alone (80, 41.5%) and PI-2b alone (23, 11.9%). The most prevalent alp gene was rib (87, 45.1%), followed by α-C (47, 24.4%), ε (33, 17.1%), alp2/3 (7, 3.6%) and alp4 (2, 1.0%), respectively. The clonal relationships between strains were investigated using multilocus sequence typing. The strains were distinguished into 26 individual sequence typing, and further clustered into 6 clonal complexes. A significant association was noted between the distributions of alp genes, serotyping and PI profiles, such as serotype III-rib-PI+PI-2a, Ib-α-C, and Ia-ε-PI-2a. No penicillin-resistant strains were detected, and 74.1%, 64.2%, and 68.9% were resistant to erythromycin, clindamycin, and tetracycline, respectively. The infective GBS isolates in China demonstrated epidemical features.
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27
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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.
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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
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