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Barros RR, Barros CC, Kegele FCO, Francisca da S N Soares M, de Paula GR. Macrolide resistance among Streptococcus agalactiae during COVID-19 public health emergency in Brazil. Braz J Microbiol 2024; 55:1445-1449. [PMID: 38687418 PMCID: PMC11153377 DOI: 10.1007/s42770-024-01356-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/22/2024] [Indexed: 05/02/2024] Open
Abstract
During COVID-19 public health emergence, azithromycin was excessively used in Brazil, as part of a controversial "early treatment", recommended by former national health authorities. Excessive usage of macrolides may increase resistance rates among beta-hemolytic streptococci. Therefore, this study aimed to investigate the occurrence of resistance to erythromycin and clindamycin among Streptococcus agalactiae recovered from February 2020 to May 2023. Bacterial isolates (n = 116) were obtained from pregnant women and submitted to antimicrobial susceptibility testing, investigation of macrolide resistance phenotypes and genotypes, and identification of capsular type. The overall rate of erythromycin not susceptible (NS) isolates was 25.9%, while resistance to clindamycin was 5.2%. Drug efflux, associated with the M phenotype and mef(A) gene, was the prevalent mechanism of resistance (80%). Capsular type Ia was predominant (39.8%), followed by II, III, and V (17.7% each). A higher diversity of types was observed in the last years of the study. Type IV has had an increasing trend over time, being the fourth most common in 2023. The majority of the isolates that expressed the M phenotype presented capsular type Ia, while those with iMLS phenotype presented capsular type V. Despite no causal relationship can be established, azithromycin excessive usage may be a possible factor associated with this higher rate of erythromycin NS isolates, compared with most previous national studies. On the other hand, resistance to clindamycin has not changed significantly. Therefore, in the studied clinical setting, clindamycin remains a useful alternative to intrapartum prophylaxis among penicillin-allergic pregnant women.
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Affiliation(s)
- Rosana Rocha Barros
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Rua Hernani de Melo 101 sala 304, 24210-130, Niterói, RJ, Brazil.
| | - Clarissa Campos Barros
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Rua Hernani de Melo 101 sala 304, 24210-130, Niterói, RJ, Brazil
| | - Fabíola C Oliveira Kegele
- Instituto Fernandes Figueira, Fundação Oswaldo Cruz, Av. Rui Barbosa 716, 22250-020, Rio de Janeiro, RJ, Brazil
| | | | - Geraldo Renato de Paula
- Faculdade de Farmácia, Universidade Federal Fluminense, Rua Dr. Mário Viana 523, 24241-000, Niterói, RJ, Brazil
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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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Effects of group B streptococcus infection on vaginal micro-ecology and pregnancy outcomes of pregnant women in late pregnancy. Eur J Obstet Gynecol Reprod Biol 2021; 267:274-279. [PMID: 34839249 DOI: 10.1016/j.ejogrb.2021.11.419] [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: 09/17/2021] [Revised: 10/05/2021] [Accepted: 11/12/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Invasive infection with group B streptococcus (GBS) can lead to intrauterine infection, and GBS can also spread via vertical transmission between mother and infant, resulting in adverse pregnancy outcomes. This study aimed to investigate the effects of GBS colonization in late gestation on vaginal micro-ecology, pregnancy outcomes and neonatal outcome. METHODS One hundred and twenty pregnant women in the third trimester infected with GBS and 120 healthy counterparts who underwent a prenatal examination in the obstetrics department of the study hospital from June 2019 to December 2020 were selected for inclusion in the study. Vaginal micro-ecological index, mode of delivery, adverse pregnancy outcomes and neonatal Apgar score were compared between the two groups. RESULTS The incidence rates of vaginal micro-ecological disorders, intrauterine infection and neonatal infection were significantly higher in the GBS group compared with the control group. The incidence rates of neonatal fetal distress and pathological jaundice were much higher in the GBS group compared with the control group. The neonatal Apgar score was markedly lower in the GBS group compared with the control group. CONCLUSIONS GBS infection is correlated with the vaginal micro-environment. GBS colonization in late pregnancy has adverse effects on vaginal micro-ecology and pregnancy outcome.
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Silvestre I, Nunes A, Borges V, Isidro J, Silva C, Vieira L, Gomes JP, Borrego MJ. Genomic insights on DNase production in Streptococcus agalactiae ST17 and ST19 strains. INFECTION GENETICS AND EVOLUTION 2021; 93:104969. [PMID: 34147652 DOI: 10.1016/j.meegid.2021.104969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 10/21/2022]
Abstract
Streptococcus agalactiae evasion from the human defense mechanisms has been linked to the production of DNases. These were proposed to contribute to the hypervirulence of S. agalactiae ST17/capsular-type III strains, mostly associated with neonatal meningitis. We performed a comparative genomic analysis between ST17 and ST19 human strains with different cell tropism and distinct DNase production phenotypes. All S. agalactiae ST17 strains, with the exception of 2211-04, were found to display DNase activity, while the opposite scenario was observed for ST19, where 1203-05 was the only DNase(+) strain. The analysis of the genetic variability of the seven genes putatively encoding secreted DNases in S. agalactiae revealed an exclusive amino acid change in the predicted signal peptide of GBS0661 (NucA) of the ST17 DNase(-), and an exclusive amino acid change alteration in GBS0609 of the ST19 DNase(+) strain. Further core-genome analysis identified some specificities (SNVs or indels) differentiating the DNase(-) ST17 2211-04 and the DNase(+) ST19 1203-05 from the remaining strains of each ST. The pan-genomic analysis evidenced an intact phage without homology in S. agalactiae and a transposon homologous to TnGBS2.3 in ST17 DNase(-) 2211-04; the transposon was also found in one ST17 DNase(+) strain, yet with a different site of insertion. A group of nine accessory genes were identified among all ST17 DNase(+) strains, including the Eco47II family restriction endonuclease and the C-5 cytosine-specific DNA methylase. None of these loci was found in any DNase(-) strain, which may suggest that these proteins might contribute to the lack of DNase activity. In summary, we provide novel insights on the genetic diversity between DNase(+) and DNase(-) strains, and identified genetic traits, namely specific mutations affecting predicted DNases (NucA and GBS0609) and differences in the accessory genome, that need further investigation as they may justify distinct DNase-related virulence phenotypes in S. agalactiae.
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Affiliation(s)
- Inês Silvestre
- Department of Life Sciences, UCIBIO, Nova School of Science and Technology, 2829-516 Caparica, Portugal; National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; CBIOS - Research Center for Biosciences & Health Technologies, Lusófona University of Humanities and Technologies, Campo Grande 376, 1749-024 Lisbon, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Joana Isidro
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Catarina Silva
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Maria José Borrego
- National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
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Li P, Wei Y, Li G, Cheng H, Xu Z, Yu Z, Deng Q, Shi Y. Comparison of antimicrobial efficacy of eravacycline and tigecycline against clinical isolates of Streptococcus agalactiae in China: In vitro activity, heteroresistance, and cross-resistance. Microb Pathog 2020; 149:104502. [PMID: 32947016 DOI: 10.1016/j.micpath.2020.104502] [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: 07/24/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 10/23/2022]
Abstract
AIMS The aims of this study were to compare the antimicrobial efficacy of Eravacycline (Erava) versus tigecycline (Tig) in vitro against clinical isolates of S. agalactiae from China and further to evaluate the heteroresistance risk and resistance mechanisms of Erava. METHODS 162 clinical isolates of S. agalactiae were collected retrospectively and the minimal inhibitory concentrations (MICs) of Erava and Tig were determined by agar dilution. Moreover, Tetracycline (Tet) specific resistance genes, genetic mutations in Tet target sites, and sequence types (ST) profiles of clinical isolates of S. agalactiae were investigated with polymerase chain reaction (PCR) experiments. The heteroresistance frequency of Erava and Tig in S. agalactiae was analyzed by population analysis profiling. Furthermore, the resistance mechanisms of both Erava and Tig were investigated in antibiotic-induced resistant S. agalactiae isolates in vitro. RESULTS The MIC values of Erava and Tig were shown with ≤0.25 mg/L and ≤0.5 mg/L, respectively, against clinical S. agalactiae isolates, including that harboring the Tet-specific resistance genes tet(K), tet(M), or tet(O). The heteroresistance frequency of Tig among the clinical isolates of S. agalactiae was 1.84% (3/162), whereas no positive Erava heteroresistance was found. The enhanced MIC values of both Erava and Tig in the heteroresistance-derivative S. agalactiae clones could be reversed by the efflux pump inhibition experiments. Genetic mutations affecting 30S ribosome units (16SrRNA copies or 30S ribosome protein S10) could result in the cross resistance toward Erava and Tig in the antibiotic-induced resistant S. agalactiae isolates in vitro. CONCLUSIONS Erava MIC values were nearly half of that of Tig against the clinical isolates of S. agalactiae from China and genetic mutations in the 30S ribosome units of Tet target sites (16SrRNA copies or 30S ribosome protein S10) participated in the resistance evolution of both Erava and Tig under the antibiotic pressure.
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Affiliation(s)
- Peiyu Li
- Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital of Guangdong Medical University, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China
| | - Ying Wei
- Heilongjiang Medical Service Management Evaluation Center, Harbin, Heilongjiang, 150031, China
| | - Guiqiu Li
- Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital of Guangdong Medical University, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; The Clinical Microbiology Lab of the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150031, China
| | - Hang Cheng
- Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital of Guangdong Medical University, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China
| | - Zhichao Xu
- Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital of Guangdong Medical University, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China
| | - Zhijian Yu
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China
| | - Qiwen Deng
- Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital of Guangdong Medical University, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
| | - Yiyi Shi
- Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital of Guangdong Medical University, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China; Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
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Silvestre I, Borrego MJ, Jordão L. Biofilm formation by ST17 and ST19 strains of Streptococcus agalactiae. Res Microbiol 2020; 171:311-318. [PMID: 32896574 DOI: 10.1016/j.resmic.2020.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 11/26/2022]
Abstract
Bacterial biofilms are an important virulence factor with a vital role in evasion from the host immune system, colonization and infection. The aim of the present study was to evaluate in vitro the effects of three environmental factors (H+, glucose and human plasma) in biofilm formation, by carrier and invasive Streptococcus agalactiae strains of ST17 and ST19 sequence types, including DNase producers and non-producers. Bacteria ability to assemble biofilms was classified based on crystal violet assay. Biofilm formation was also monitored by scanning electron microscopy. Depending on the growth medium used, each bacterial isolate could fit in different biofilm production categories. Our data showed that optimal conditions for S. agalactiae biofilm assembly were reached after 48 h incubation at pH 7.6 in the presence of glucose and inactivated human plasma. In the presence of inactivated human plasma, the biofilm biomass of ST19 strains experienced a higher increase than ST17 strains. The composition of the extracellular polymeric matrix of the three strongest biofilm producers (all from ST17) was accessed by enzymatic digestion of mature biofilms and proteins were shown to be the predominant component. The detailed identification of the extracellular protein components should contribute to the development of new therapeutic strategies to fight S. agalactiae infections.
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Affiliation(s)
- Inês Silvestre
- Department of Life Sciences, UCIBIO, Nova School of Science and Technology, 2829-516 Caparica, Portugal; Department of Infectious Diseases, National Institute of Health Doutor Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Maria José Borrego
- Department of Infectious Diseases, National Institute of Health Doutor Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Luísa Jordão
- Department of Environmental Health, Research and Development Unit, National Institute of Health Doutor Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
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Mohamed AM, Khan MA, Faiz A, Ahmad J, Khidir EB, Basalamah MA, Aslam A. Group B Streptococcus Colonization, Antibiotic Susceptibility, and Serotype Distribution among Saudi Pregnant Women. Infect Chemother 2020; 52:70-81. [PMID: 32239812 PMCID: PMC7113445 DOI: 10.3947/ic.2020.52.1.70] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/04/2020] [Indexed: 11/24/2022] Open
Abstract
Background Group B Streptococcus (GBS) comprises the normal flora of the female urogenital tract and can be transferred to neonates during delivery, causing invasive diseases. This study was performed to investigate the colonization rate, antibiotic susceptibility, and serotype of GBS among Saudi pregnant women. Materials and Methods In this cross-sectional study, vagino-rectal swabs from 400 pregnant women were collected over a period of one year. Identification of GBS isolates and determination of their antibiotic susceptibility were performed using the Microscan Walk Away system. The isolates were then typed using both latex agglutination and capsular gene-based multiplex polymerase chain reaction assays. Results Sixty (15.0%) subjects were colonized by GBS, with serotype Ia as the dominant type (30.0%) followed by serotype III and V (25.0%, each). Only 43 (71.7%) isolates were typed by latex agglutination, whereas the remaining isolates were not typable or were non-specifically typed as compared to the genotyping assay, which revealed the specific type of each GBS isolate. The highest resistance rates were observed for erythromycin and clindamycin (16.7%, each), which were mainly restricted to the prevalent serotypes. Conclusion This study is the first to report the distribution of GBS serotypes based on molecular genotyping in Saudi Arabia. GBS colonization was evident among pregnant women, and resistance to erythromycin and clindamycin was predominant among serotypes Ia, III, and V. Molecular genotyping using capsular gene-based multiplex PCR provided reliable typing of the investigated GBS isolates in terms of sensitivity and specificity as compared to conventional serotyping using latex agglutination.
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Affiliation(s)
- Amr Mohamed Mohamed
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al Qura University, Makkah, Saudi Arabia.,Clinical Laboratory Diagnosis, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Mubashir Ahmad Khan
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al Qura University, Makkah, Saudi Arabia.
| | - Aftab Faiz
- Microbiology Department, Maternity and Children hospital, Makkah, Saudi Arabia
| | - Jawwad Ahmad
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al Qura University, Makkah, Saudi Arabia
| | - Elsheikh Babiker Khidir
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al Qura University, Makkah, Saudi Arabia
| | | | - Akhmed Aslam
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al Qura University, Makkah, Saudi Arabia
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Kardos S, Tóthpál A, Laub K, Kristóf K, Ostorházi E, Rozgonyi F, Dobay O. High prevalence of group B streptococcus ST17 hypervirulent clone among non-pregnant patients from a Hungarian venereology clinic. BMC Infect Dis 2019; 19:1009. [PMID: 31779587 PMCID: PMC6883650 DOI: 10.1186/s12879-019-4626-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 11/11/2019] [Indexed: 11/08/2022] Open
Abstract
Background Although Streptococcus agalactiae is the leading causative agent of neonatal sepsis and meningitis, recently it is increasingly isolated from non-pregnant adults. The relation between its presence in the genitourinary tract and manifested clinical symptoms of STD patients remains an open question. In this study, a complex epidemiological investigation of GBS isolates from a venerology clinic was performed. Methods Ninety-six GBS isolates were serotyped and their genetic relatedness determined by PFGE. MLST was also performed for a subset of 20 isolates. The antibiotic susceptibility was tested with agar dilution. Surface proteins and the ST-17 hypervirulent clone was detected by PCR. Results The serotype prevalence was the following: V (29.2%), III (27.1%), Ia (22.9%), IV (10.4%), II (5.2%) and Ib (4.2%). A strong association was demonstrated between surface protein genes and serotypes. All isolates were fully susceptible to penicillin, but erythromycin and clindamycin resistance was high (41.7 and 35.4%, respectively), and 8 phenotypically macrolide sensitive isolates carried the ermB gene. 21.9% of all strains belonged to the hypervirulent ST17 clone, most being of serotype III and all were rib +. We found a few serotype IV isolates belonging to several STs and one serotype V/ST110 strain, containing a 44-bp deletion in the atr allele. Conclusions The presence of silent ermB genes is of worry, as their expression upon macrolide exposure could lead to unforeseen therapeutic failure, while clindamycin is used for intrapartum antibiotic prophylaxis, in case of penicillin allergy. The other alarming result is the high prevalence of ST17 among these strains from STD patients, who could be sources of further infections. This is the first report from Hungary providing both serotyping and genotyping data of GBS isolates. These results could be helpful for vaccine production as the major vaccine candidates are capsular antigens or surface proteins.
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Affiliation(s)
- Szilvia Kardos
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, H-1089, Hungary
| | - Adrienn Tóthpál
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, H-1089, Hungary
| | - Krisztina Laub
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, H-1089, Hungary
| | - Katalin Kristóf
- Institute of Laboratory Medicine, Semmelweis University, Budapest, Hungary
| | - Eszter Ostorházi
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, H-1089, Hungary.,Department of Dermatology, Dermatooncology and Venerology, Semmelweis University, Budapest, Hungary
| | - Ferenc Rozgonyi
- Institute of Laboratory Medicine, Semmelweis University, Budapest, Hungary.,Department of Dermatology, Dermatooncology and Venerology, Semmelweis University, Budapest, Hungary
| | - Orsolya Dobay
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, H-1089, Hungary.
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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: 6] [Impact Index Per Article: 1.2] [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.
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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
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Clinical and Microbiological Characteristics of Group B Streptococcus from Pregnant Women and Diseased Infants in Intrapartum Antibiotic Prophylaxis Era in Taiwan. Sci Rep 2019; 9:13525. [PMID: 31537886 PMCID: PMC6753095 DOI: 10.1038/s41598-019-49977-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/15/2019] [Indexed: 01/09/2023] Open
Abstract
Group B Streptococcus (GBS) is one of the most important pathogens for neonates. This study included 69 invasive GBS diseases in neonates, including 7 early-onset disease (EOD), 55 late-onset disease, and 7 very-late-onset disease from 2013 to 2017. A significant reduction of EOD after the deployment of intrapartum antibiotic prophylaxis (IAP) in 2012 was observed. A previously-recognized hypervirulent clone GBS III ST17, accounting for 68% of the overall infections and 71% of the meningitis, was identified among the 69 cases. A novel GBS Ia ST890 emerged, becoming the fourth most common clone. Overall 96% of the invasive GBS infections were caused by serotypes Ia, Ib, and III. We collected 300 GBS isolates from vagina of the healthy pregnant women in 2014 and 2017. The serotype distribution of the maternal colonization isolates was VI (35%), III (21%), V (15%), Ib (13%) and Ia (11%) in 2014, and VI (32%), III (22%), V (16%), Ia (16%), and Ib (8%) in 2017. The most common sequence types were ST1 (32%), ST12 (22%), and ST23 (15%). Serotype diversity of maternal colonization strains did not change between 2014 and 2017. The study provides useful information in surveillance of GBS disease in the era of IAP.
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11
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Emerging serotype III sequence type 17 group B streptococcus invasive infection in infants: the clinical characteristics and impacts on outcomes. BMC Infect Dis 2019; 19:538. [PMID: 31216993 PMCID: PMC6585028 DOI: 10.1186/s12879-019-4177-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/10/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is an important pathogen that causes high mortality and morbidity in young infants. However, data on clinical manifestations between different GBS serotypes and correlation with molecular epidemiology are largely incomplete. The aim of this study was to determine the serotype distribution, antimicrobial resistance, clinical features and molecular characteristics of invasive GBS isolates recovered from Taiwanese infants. METHODS From 2003 to 2017, 182 non-duplicate GBS isolates that caused invasive disease in infants less than one year of age underwent serotyping, multilocus sequence typing (MLST) and antibiotic susceptibility testing. The clinical features of these infants with GBS disease were also reviewed. RESULTS Of the 182 patients with invasive GBS disease, 41 (22.5%) were early-onset disease, 121 (66.5%) were late-onset disease and 20 (11.0%) were late late-onset disease (> 90 days of age). All these patients were treated with effective antibiotics on time. Among them, 51 (28.0%) had meningitis, 29 (16.0%) had neurological complications, 12 (6.6%) died during hospitalization, and 15 (8.8%) out of 170 patients who survived had long-term neurological sequelae at discharge. Serotype III GBS strains accounted for 64.8%, followed by serotype Ia (18.1%) and Ib (8.2%). MLST analysis revealed 11 different sequence types among the 182 isolates and ST-17 was the most dominant sequence type (56.6%). The correlation between serotype III and ST17 was evident, as ST17 accounted for 87.3% of all serotype III isolates. There was an obvious increasing trend of type III/ST-17 GBS that caused invasive disease in infants. All isolates were susceptible to penicillin, cefotaxime, and vancomycin, while 68.1 and 65.9% were resistant to erythromycin and clindamycin, respectively. CONCLUSIONS Despite timely and appropriate antibiotic treatment, a significant proportion of invasive GBS disease still inevitably causes adverse outcomes. Further study to explore preventive strategies and development of serotype-based vaccines will be necessary in the future.
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12
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Lin SM, Jang AY, Zhi Y, Gao S, Lim S, Lim JH, Song JY, Sullam PM, Rhee JH, Seo HS. Vaccination With a Latch Peptide Provides Serotype-Independent Protection Against Group B Streptococcus Infection in Mice. J Infect Dis 2019; 217:93-102. [PMID: 29106586 DOI: 10.1093/infdis/jix565] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/24/2017] [Indexed: 11/14/2022] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) is a leading cause of invasive diseases in neonates and severe infections in elderly individuals. GBS serine-rich repeat glycoprotein 1 (Srr1) acts as a critical virulence factor by facilitating GBS invasion into the central nervous system through interaction with the fibrinogen Aα chain. This study revealed that srr1 is highly conserved, with 86.7% of GBS clinical isolates expressing the protein. Vaccination of mice with different Srr1 truncated peptides revealed that only Srr1 truncates containing the latch domain protected against GBS meningitis. Furthermore, the latch peptide alone was immunogenic and elicited protective antibodies, which efficiently enhanced antibody-mediated opsonophagocytic killing of GBS by HL60 cells and provided heterogeneous protection against 4 different GBS serogroups. Taken together, these findings indicated that the latch domain of Srr1 may constitute an effective peptide vaccine candidate for GBS.
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Affiliation(s)
- Shun-Mei Lin
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup.,Brain Korea 21 Program for Leading Universities and Students, Department of Molecular Medicine, Chonnam National University Medical School, Gwangju
| | - A-Yeung Jang
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup.,Department of Biological Sciences, Chonbuk National University, Jeonju
| | - Yong Zhi
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup.,Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon
| | - Shuang Gao
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup.,Brain Korea 21 Program for Leading Universities and Students, Department of Molecular Medicine, Chonnam National University Medical School, Gwangju
| | - Sangyong Lim
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup.,Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon
| | - Jae Hyang Lim
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon
| | - Joon Young Song
- Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea
| | - Paul M Sullam
- Department of Microbiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea.,Division of Infectious Diseases, Veterans Affairs Medical Center, University of California-San Francisco, San Francisco, California.,Department of Medicine, University of California-San Francisco, San Francisco, California.,Northern California Institute for Research and Education, San Francisco, California
| | - Joon Haeng Rhee
- Brain Korea 21 Program for Leading Universities and Students, Department of Molecular Medicine, Chonnam National University Medical School, Gwangju.,Department of Microbiology, Chonnam National University Medical School, Gwangju.,Clinical Vaccine Research and Development Center, Chonnam National University Medical School, Gwangju
| | - Ho Seong Seo
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup.,Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon
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13
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Florindo C, Barroco CA, Silvestre I, Damião V, Gomes JP, Spellerberg B, Santos-Sanches I, Borrego MJ. Capsular Type, Sequence Type and Microbial Resistance Factors Impact on DNase Activity of Streptococcus agalactiae Strains from Human and Bovine Origin. Eur J Microbiol Immunol (Bp) 2018; 8:149-154. [PMID: 30719332 PMCID: PMC6348702 DOI: 10.1556/1886.2018.00026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/13/2018] [Indexed: 12/20/2022] Open
Abstract
Extracellular deoxyribonucleases (DNases) contribute to the spread of pathogenic bacteria through the evasion from host innate immunity. Our main objective was to evaluate the production of extracellular DNases by human and bovine Streptococcus agalactiae clinical strains and perform a correlation of genetic lineages and DNase activity with capsular type, genetic determinants, clinical origin (colonization and infection), and host (human or bovine). DNase activity was evaluated by qualitative and quantitative assays for a collection of 406 human (n = 285) and bovine (n = 121) strains. All (121/121) bovine were isolated from mastitis and revealed to be DNase (+), indicating a putative pathogenic role in this clinical scenario. From the human S. agalactiae strains, 86% (245/285) showed DNase activity, among which all strains belonging to capsular types, namely, Ia, Ib, III-2, and IV. All CC17 strains (n = 58) and 56/96 (58.3%) of the CC19 displayed DNase activity. DNase (-) strains belonged to the CC19 group. However, the subcharacterization of CC19 S. agalactiae strains through multiple-locus variable number tandem repeat analysis (MLVA), antibiotic resistance, mobile elements, and surface proteins did not provide any distinction among DNase producers and non-producers. The production of DNases by all human CC17 strains, about two-fifths of human CC19, and all bovine strains, suggest an important contribution of DNases to hypervirulence.
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Affiliation(s)
- Carlos Florindo
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | - Cinthia Alves Barroco
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
| | - Inês Silvestre
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | - Vera Damião
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | - João Paulo Gomes
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | | | - Ilda Santos-Sanches
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
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14
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Perinatal Streptococcus agalactiae Epidemiology and Surveillance Targets. Clin Microbiol Rev 2018; 31:31/4/e00049-18. [PMID: 30111577 DOI: 10.1128/cmr.00049-18] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus agalactiae, or group B streptococcus (GBS), is a major neonatal pathogen. Recent data have elucidated the global prevalence of maternal and neonatal colonization, but gaps still remain in the epidemiology of this species. A number of phenotypic and genotypic classifications can be used to identify the diversity of GBS strains, and some are more discriminatory than others. This review explores the main schemes used for GBS epidemiology and further details the targets for epidemiological surveillance. Current screening practices across the world provide a unique opportunity to gain detailed information on maternal colonizing strains and neonatal disease-causing strains, which is vital for monitoring and therapeutics, if sufficient detail can be extracted. Deciphering which isolates are circulating within specific populations and recording targets within invasive strains are crucial steps in monitoring the implementation of therapeutics, such as vaccines, as well as developing novel therapies against prevalent GBS strains. Having a detailed understanding of global GBS epidemiology will prove invaluable for understanding the pathogenesis of this organism and equipping future prevention strategies for success.
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15
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Shabayek S, Spellerberg B. Group B Streptococcal Colonization, Molecular Characteristics, and Epidemiology. Front Microbiol 2018; 9:437. [PMID: 29593684 PMCID: PMC5861770 DOI: 10.3389/fmicb.2018.00437] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/26/2018] [Indexed: 11/13/2022] Open
Abstract
Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of serious neonatal infections. GBS is an opportunistic commensal constituting a part of the intestinal and vaginal physiologic flora and maternal colonization is the principal route of GBS transmission. GBS is a pathobiont that converts from the asymptomatic mucosal carriage state to a major bacterial pathogen causing severe invasive infections. At present, as many as 10 serotypes (Ia, Ib, and II–IX) are recognized. The aim of the current review is to shed new light on the latest epidemiological data and clonal distribution of GBS in addition to discussing the most important colonization determinants at a molecular level. The distribution and predominance of certain serotypes is susceptible to variations and can change over time. With the availability of multilocus sequence typing scheme (MLST) data, it became clear that GBS strains of certain clonal complexes possess a higher potential to cause invasive disease, while other harbor mainly colonizing strains. Colonization and persistence in different host niches is dependent on the adherence capacity of GBS to host cells and tissues. Bacterial biofilms represent well-known virulence factors with a vital role in persistence and chronic infections. In addition, GBS colonization, persistence, translocation, and invasion of host barriers are largely dependent on their adherence abilities to host cells and extracellular matrix proteins (ECM). Major adhesins mediating GBS interaction with host cells include the fibrinogen-binding proteins (Fbs), the laminin-binding protein (Lmb), the group B streptococcal C5a peptidase (ScpB), the streptococcal fibronectin binding protein A (SfbA), the GBS immunogenic bacterial adhesin (BibA), and the hypervirulent adhesin (HvgA). These adhesins facilitate persistent and intimate contacts between the bacterial cell and the host, while global virulence regulators play a major role in the transition to invasive infections. This review combines for first time epidemiological data with data on adherence and colonization for GBS. Investigating the epidemiology along with understanding the determinants of mucosal colonization and the development of invasive disease at a molecular level is therefore important for the development of strategies to prevent invasive GBS disease worldwide.
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Affiliation(s)
- Sarah Shabayek
- Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany
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16
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Edwards MS, Rench MA, Rinaudo CD, Fabbrini M, Tuscano G, Buffi G, Bartolini E, Bonacci S, Baker CJ, Margarit I. Immune Responses to Invasive Group B Streptococcal Disease in Adults. Emerg Infect Dis 2018; 22:1877-1883. [PMID: 27767008 PMCID: PMC5088039 DOI: 10.3201/eid2211.160914] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Antibodies to capsular polysaccharides and pilus proteins develop in recovering adults. Immunization of nonpregnant adults could help prevent invasive group B Streptococcus (GBS) infections, but adult immune responses have not been investigated. We defined capsular polysaccharide (CPS) and pilus island (PI) surface antigen distribution and expression and immune responses to GBS infection in nonpregnant adults. Prospective surveillance from 7 hospitals in Houston, Texas, USA, identified 102 adults with GBS bacteremia; 43% had skin/soft tissue infection, 16% bacteremia without focus, and 12% osteomyelitis. CPS-specific IgG was determined by ELISA and pilus-specific IgG by multiplex immunoassay. CPS types were Ia (24.5%), Ib (12.7%), II (9.8%), III (16.7%), IV (13.7%), and V (12.7%); 9.8% were nontypeable by serologic methods. Pili, expressed by 89%, were most often PI-2a. CPS and pilus-specific IgG increased during convalescence among patients with strains expressing CPS or PI. All GBS expressed CPS or PI; 79% expressed both. Increased antibodies to CPS and PI during recovery suggests that GBS bacteremia in adults is potentially vaccine preventable.
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17
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Choi MJ, Noh JY, Cheong HJ, Kim WJ, Lin SM, Zhi Y, Lim JH, Lim S, Seo HS, Song JY. Development of a multiplexed opsonophagocytic killing assay (MOPA) for group B Streptococcus. Hum Vaccin Immunother 2017; 14:67-73. [PMID: 28933634 DOI: 10.1080/21645515.2017.1377379] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Group B Streptococcus (GBS) is a leading cause of sepsis in infants as well as chorioamnionitis in pregnant women. Opsonophagocytic killing assays (OPAs) are an essential technique in vaccine studies of encapsulated bacteria for estimating serotype-specific functional antibody levels in vitro. Here, we developed a three-fold multiplexed OPA (MOPA) to enable practical, large-scale assessment of GBS vaccine immunogenicity, including against serotypes Ia, III, and V. First, three target bacteria strains resistant to streptomycin, spectinomycin, or kanamycin were generated by natural selection through exposure to increasing antibiotic concentrations. Since a high level of nonspecific killing (NSK) of serotype V was observed in a 12.5% baby rabbit complement (BRC) solution, the BRC concentration was optimized. The final GBS-MOPA BRC concentration was 9%, which resulted in less than 20% NSK. The specificity was measured by preabsorbing serum with inactivated GBS. The opsonic index (OI) of preabsorbed serum with the homologous serotype GBS was significantly reduced in all three serotypes tested. The accuracy of the MOPA was compared with that of a single OPA (SOPA) with 35 serum samples. The OIs of the MOPA correlated well with those of the SOPA, and the r2 values were higher than 0.950 for all three serotypes. The precision of the MOPA assay was assessed in five independent experiments with five serum samples. The inter-assay precision of the GBS-MOPA was 12.5% of the average coefficient of variation. This is the first report to develop and standardize a GBS-MOPA, which will be useful for GBS vaccine development and evaluation.
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Affiliation(s)
- Min Joo Choi
- a Department of Internal Medicine , Korea University College of Medicine , Seoul , Republic of Korea
| | - Ji Yun Noh
- a Department of Internal Medicine , Korea University College of Medicine , Seoul , Republic of Korea
| | - Hee Jin Cheong
- a Department of Internal Medicine , Korea University College of Medicine , Seoul , Republic of Korea
| | - Woo Joo Kim
- a Department of Internal Medicine , Korea University College of Medicine , Seoul , Republic of Korea
| | - Shun-Mei Lin
- b Biotechnology Division, Korea Atomic Energy Research Institute , Jeongeup , Republic of Korea
| | - Yong Zhi
- b Biotechnology Division, Korea Atomic Energy Research Institute , Jeongeup , Republic of Korea
| | - Jae Hyang Lim
- c Department of Microbiology and Tissue Injury Defense Research Center , Ewha Womans University School of Medicine , Seoul , Republic of Korea
| | - Sangyong Lim
- b Biotechnology Division, Korea Atomic Energy Research Institute , Jeongeup , Republic of Korea
| | - Ho Seong Seo
- b Biotechnology Division, Korea Atomic Energy Research Institute , Jeongeup , Republic of Korea
| | - Joon Young Song
- a Department of Internal Medicine , Korea University College of Medicine , Seoul , Republic of Korea
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18
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Simoni S, Vincenzi C, Brenciani A, Morroni G, Bagnarelli P, Giovanetti E, Varaldo PE, Mingoia M. Molecular Characterization of Italian Isolates of Fluoroquinolone-Resistant Streptococcus agalactiae and Relationships with Chloramphenicol Resistance. Microb Drug Resist 2017; 24:225-231. [PMID: 28783417 DOI: 10.1089/mdr.2017.0139] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A total number of 368 clinical isolates of Streptococcus agalactiae (group B Streptococcus, GBS) were collected in 2010-2016 from three hospitals in a region of central Italy. Fluoroquinolone (FQ)-resistant isolates were selected using levofloxacin. Levofloxacin-resistant (LR) strains (11/368, 2.99%) were characterized for several features, and their FQ resistance was analyzed phenotypically and genotypically using seven additional FQs. Their gyrA and parC quinolone resistance-determining regions were sequenced. Of the 11 LR isolates, 10 showed high-level and 1 low-level resistance. The former isolates exhibited higher minimal inhibitory concentrations also of the other FQs and all shared one amino acid substitution in ParC (Ser79Phe) and one in GyrA (Ser81Leu); only Ser79Phe in ParC was detected in the low-level LR isolate. The 11 LR strains exhibited distinctive relationships between their susceptibilities to non-FQ antibiotics and typing data. Remarkably, despite the very rare occurrence of chloramphenicol resistance in S. agalactiae, no <4 of the 11 LR isolates were chloramphenicol-resistant. Studies of GBS resistance to FQs in Europe remain scarce, notwithstanding the emergence of multidrug-resistant isolates. The incidence of LR GBS isolates is still limited in Italy, consistent with the moderate (though growing) rates reported in Europe, and much lower than the very high rates reported in East Asia. The intriguing relationships between FQ and chloramphenicol resistance deserve further investigation.
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Affiliation(s)
- Serena Simoni
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy
| | - Chiara Vincenzi
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy .,2 Clinical Microbiology Laboratory, Torrette Regional Hospital , Ancona, Italy
| | - Andrea Brenciani
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy
| | - Gianluca Morroni
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy
| | - Patrizia Bagnarelli
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy
| | - Eleonora Giovanetti
- 3 Department of Life and Environmental Sciences, Polytechnic University of Marche , Ancona, Italy
| | - Pietro E Varaldo
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy
| | - Marina Mingoia
- 1 Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School , Ancona, Italy
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Identification of Group B Streptococcus Capsule Type by Use of a Dual Phenotypic/Genotypic Assay. J Clin Microbiol 2017; 55:2637-2650. [PMID: 28615470 DOI: 10.1128/jcm.00300-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 06/08/2017] [Indexed: 11/20/2022] Open
Abstract
The group B streptococcus (GBS) capsular polysaccharide (CPS) is an important virulence factor which is also used for GBS typing. There are 10 CPS types (Ia, Ib, and II to IX). GBS that do not phenotypically type are considered nontypeable. All genes required for CPS synthesis are found on the GBS cps operon, which contains a highly variable CPS-determining region (cpsG-cpsK). The objective of this study was development of an assay to detect sialic acid on the GBS cell surface, followed by a genotypic PCR CPS typing assay. Sialic acid is located at the terminal end of the side chain of all known GBS CPS types. Sialic acid can be bound to commercially available lectins such as slug Limax flavus lectin. Biotinylated L. flavus-streptavidin-peroxidase complex was used in an enzyme immunoassay and dot blot assay to detect sialic acid. This was followed by a PCR typing scheme that was developed to target the serotype-determining region of the cps locus for Ia, Ib, and II to IX. Sialic acid from the CPS types Ia, Ib, and II to IX was detectable on the GBS cell surfaces of all previously identified CPS-typed GBS strains assayed. This was followed by the real-time PCR typing assay which successfully identified CPS Ia, Ib, and II to IX types. The combination of phenotypic and genotypic assays provides an accurate tool for detection of CPS expression and assignment of CPS typing. These assays have the potential to be used for CPS typing in large-scale epidemiological studies.
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20
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Kuleshevich E, Ferretti J, Santos Sanches I, Balasubramanian N, Spellerberg B, Efstratiou A, Kriz P, Grabovskaya K, Arjanova O, Savitcheva A, Shevchenko V, Rysev A, Suvorov A. Clinical strains of Streptococcus agalactiae carry two different variants of pathogenicity island XII. Folia Microbiol (Praha) 2017; 62:393-399. [PMID: 28315021 DOI: 10.1007/s12223-017-0509-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 02/21/2017] [Indexed: 01/12/2023]
Abstract
Streptococcus agalactiae or Group B streptococci (GBS) are a common cause of serious diseases of newborns and adults. GBS pathogenicity largely depends on genes located on the accessory genome including several pathogenicity islands (PAI). The present paper is focused on the structure and molecular epidemiological analysis of one of the GBS pathogenicity islands-the pathogenicity island PAI XII (Glaser et al. Mol Microbiol 45(6):1499-1513, 2002). This PAI was found to be composed of three different mobile genetic elements: a composite transposon (PAI-C), a genomic islet (PAI-B), and a pathogenicity island associated with gene sspB1 (PAI-A). PAI-A in GBS has a homolog--PAI-A1 with similar, but a different genetic constellation. PCR-based analysis of GBS collections from different countries revealed that a strains lineage with PAI-A is less common than PAI-A1 and was determined to be present only among the strains obtained from Russia. Our results suggest that PAI-A and PAI-A1 have the same progenitor, which evolved independently and appeared in the GBS genome as separate genetic events. Results of this study reflect specific geographical distribution of the GBS strains with the mobile genetic element under study.
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Affiliation(s)
- Eugenia Kuleshevich
- Institute of Experimental Medicine, Pavlova Street, 12, 197376, Saint-Petersburg, Russia
| | - Joseph Ferretti
- University of Oklahoma Health Sciences Center, 1100 N Lindsay Ave, Oklahoma City, OK, 73104, USA
| | - Ilda Santos Sanches
- Research Unit on Applied Molecular Biosciences (UCIBIO@REQUIMTE). Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Natesan Balasubramanian
- Research Unit on Applied Molecular Biosciences (UCIBIO@REQUIMTE). Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | | | - Paula Kriz
- WHO Center Reference and Research on Streptococci, Srobarova, 48 10042 10, Prague, Czech Republic
| | - Kornelia Grabovskaya
- Institute of Experimental Medicine, Pavlova Street, 12, 197376, Saint-Petersburg, Russia
| | - Olga Arjanova
- D. O. Ott Research Institute of Obstetrics and Gynecology, 199034, Mendeleevskaya line, 3, Saint-Petersburg, Russia
| | - Alevtina Savitcheva
- D. O. Ott Research Institute of Obstetrics and Gynecology, 199034, Mendeleevskaya line, 3, Saint-Petersburg, Russia
| | - Valentin Shevchenko
- Institute of Experimental Medicine, Pavlova Street, 12, 197376, Saint-Petersburg, Russia
| | - Anton Rysev
- Institute of Experimental Medicine, Pavlova Street, 12, 197376, Saint-Petersburg, Russia
| | - Alexander Suvorov
- Institute of Experimental Medicine, Pavlova Street, 12, 197376, Saint-Petersburg, Russia.
- Saint-Petersburg State University, 199034, Universitetskaya emb. 7/9, Saint-Petersburg, Russia.
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Neonatal Group B Streptococcus Infections: Prevention Strategies, Clinical and Microbiologic Characteristics in 7 Years of Surveillance. Pediatr Infect Dis J 2017; 36:256-262. [PMID: 27870810 DOI: 10.1097/inf.0000000000001414] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The characteristics of group B streptococcus (GBS) neonatal disease in a period of 7 years are reported. METHODS The estimation of the neonatal GBS disease risk and prevention strategies adopted at delivery in absence of national guidelines was evaluated by the analysis of 3501 questionnaires. Notification of 194 neonatal GBS infections was recorded. In addition, 115 strains from neonatal early-onset disease (EOD) and late-onset disease, respectively, plus 320 strains from pregnant women were analyzed by molecular typing methods and for antibiotic resistance. RESULTS Preterm deliveries, precipitous labor and GBS negatively screened mothers were the prominent causes for an inadequate or lack of intrapartum antibiotic prophylaxis and EOD occurrence. The superimposable serotype distribution of GBS strains from EOD and from antenatal screening confirmed the vertical transmission from mother to neonate as the cause of disease. On the contrary, late-onset disease was almost exclusively caused by the internationally diffused clonal complex 17. Erythromycin resistance was detected in 17% of strains. Resistance to clindamycin was 15.3 %. CONCLUSIONS The administration of intrapartum antibiotic prophylaxis to negatively GBS screened women in presence of risk factors was a deviation from the recommendations issued by the Centers for Disease Control and Prevention, and it should deserve further consideration. Routine surveillance and molecular typing of circulating clones are essential for the effective management of the neonatal GBS disease.
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Serotype Distribution, Population Structure, and Antimicrobial Resistance of Group B Streptococcus Strains Recovered from Colonized Pregnant Women. J Clin Microbiol 2016; 55:412-422. [PMID: 27852675 DOI: 10.1128/jcm.01615-16] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/12/2016] [Indexed: 11/20/2022] Open
Abstract
Using serotyping, multilocus sequence typing, and whole-genome sequencing (WGS) of selected strains, we studied the population structure of 102 group B Streptococcus (GBS) isolates prospectively sampled in 2014 from vaginal/rectal swabs of healthy pregnant women in metropolitan Toronto, Canada. We also determined the susceptibilities of each of the colonizing isolates to penicillin, erythromycin, clindamycin, tetracycline, and other antimicrobial agents. Overall, we observed a high rate of tetracycline resistance (89%) among colonizing GBS isolates. We found resistance to erythromycin in 36% of the strains, and 33% were constitutively or inducibly resistant to clindamycin. The most frequently identified serotypes were III (25%), Ia (23%), and V (19%). Serotype IV accounted for 6% of the colonizing isolates, a rate consistent with that observed among patients with invasive GBS infections in metropolitan Toronto. The majority of serotype IV isolates belonged to sequence type (ST)459, a tetracycline-, erythromycin-, and clindamycin-resistant ST first identified in Minnesota, which is considered to be the main driver of serotype IV GBS expansion in North America. WGS revealed that ST459 isolates from Canada are clonally related to colonizing and invasive ST459 organisms circulating in regions of the United States. We also used WGS to study recombination in selected colonizing strains from metropolitan Toronto, which revealed multiple episodes of capsular switching. Present and future circulating GBS organisms and their genetic diversity may influence GBS vaccine development.
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Streptococcus agalactiaefrom pregnant women: antibiotic and heavy-metal resistance mechanisms and molecular typing. Epidemiol Infect 2016; 144:3205-3214. [DOI: 10.1017/s0950268816001692] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
SUMMARYWe investigated the antibiotic and heavy-metal resistance mechanisms, virulence genes and clonal relationships of macrolide- and/or lincosamide-resistant (M+/−LR)Streptococcus agalactiae(group BStreptococcus, GBS) isolates from pregnant women in La Rioja in Northern Spain, a region with a significant immigrant population. In total 375 GBS isolates were recovered during 2011. About three-quarters of isolates were from European nationals and the remainder distributed among 23 other nationalities. Seventy-five (20%) were classified as M+/−LRstrains and 28 (37%) of these were resistant to ⩾3 classes of antibiotics. Capsular serotypes III (29·3%), V (21·3%) and II (12%) were the most frequent. A wide variety of antibiotic resistance genes were detected in M+/−LRstrains; notably, 5·3% harboured thelsa(C) gene associated with cross-resistance, andtet(W) was identified in a single strain. We report, for the first time, the detection of cadmium and copper resistance encoded bytcrB+cadA+cadCgenes in 20 M+/−LRstrains, which raises the possibility of co-selection of antibiotic and heavy-metal resistance disseminated through mobile genetic elements. The M+/−LRstrains were highly diverse by DNA macrorestriction profiles (65 patterns) and 16 multilocus sequence types (STs) distributed among six clonal complexes; the most frequent were ST1, ST19, and ST12, and two strains were novel (ST586 and ST601). In conclusion, a wide diversity of genetic lineages of macrolide, lincosamide and heavy-metal- resistant GBS strains was observed in an ethnically diverse maternal population.
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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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Epidemiology of Invasive Group B Streptococcal Disease in Alberta, Canada, from 2003 to 2013. J Clin Microbiol 2016; 54:1774-1781. [PMID: 27098960 DOI: 10.1128/jcm.00355-16] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/12/2016] [Indexed: 11/20/2022] Open
Abstract
Group B streptococci (GBS) cause severe invasive disease in both neonates and adults. Understanding the epidemiology of GBS provides information that can include determining disease prevalence rates in defined populations and geographic regions, documenting the success of GBS screening programs, and understanding antimicrobial susceptibility patterns. In Alberta, only neonatal invasive GBS (iGBS) disease is notifiable to health authorities. We performed a surveillance study of iGBS in Alberta, Canada, from 2003 to 2013. Over the 11-year period, the disease incidence rate increased from a low of 3.92 cases/100,000 population to a high of 5.99 cases/100,000 population. The capsular polysaccharide serotypes (CPSs) found were CPS III (20.3%), CPS V (19.1%), CPS Ia (18.9%), CPS Ib (12.7%), CPS II (11.1%), CPS IV (6.3%), and nontypeable GBS (9.4%). Rates of early-onset disease (0 to 7 days) increased from 0.15 cases/1,000 live births (in 2003) to 0.34 cases/1,000 live births (in 2013). Rates of late-onset disease (>7 to 90 days) also rose, from 0.15 cases/1,000 live births (in 2003) to 0.39 cases/1,000 live births (in 2013). Alberta also experienced an increase in CPS IV isolates, from 2 cases (in 2003) to 24 cases (in 2013), of which the majority were hvgA negative (93.4%) [corrected]. The predominant sequence type (ST) in 2013 was ST459. Erythromycin resistance rose from 23.6% to 43.9% (in 2013). Clindamycin resistance also increased, from 12.2% to 32.5%. In summary, Alberta, Canada, has experienced an increase in GBS disease; the increase includes both neonatal and adult disease. CPS IV cases also notably increased during the surveillance period, as did resistance to erythromycin and clindamycin.
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Barros RR, de Souza AF, Luiz FBO. Polyclonal spread of Streptococcus agalactiae resistant to clindamycin among pregnant women in Brazil. J Antimicrob Chemother 2016; 71:2054-6. [PMID: 27029847 DOI: 10.1093/jac/dkw085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Rosana Rocha Barros
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
| | - Andréa Farias de Souza
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
| | - Fernanda Baptista Oliveira Luiz
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
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Chromosomally and Extrachromosomally Mediated High-Level Gentamicin Resistance in Streptococcus agalactiae. Antimicrob Agents Chemother 2016; 60:1702-7. [PMID: 26729498 DOI: 10.1128/aac.01933-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/09/2015] [Indexed: 11/20/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis in neonates. The rate of invasive GBS disease in nonpregnant adults also continues to climb. Aminoglycosides alone have little or no effect on GBS, but synergistic killing with penicillin has been shown in vitro. High-level gentamicin resistance (HLGR) in GBS isolates, however, leads to the loss of a synergistic effect. We therefore performed a multicenter study to determine the frequency of HLGR GBS isolates and to elucidate the molecular mechanisms leading to gentamicin resistance. From eight centers in four countries, 1,128 invasive and colonizing GBS isolates were pooled and investigated for the presence of HLGR. We identified two strains that displayed HLGR (BSU1203 and BSU452), both of which carried the aacA-aphD gene, typically conferring HLGR. However, only one strain (BSU1203) also carried the previously described chromosomal gentamicin resistance transposon designated Tn3706. For the other strain (BSU452), plasmid purification and subsequent DNA sequencing resulted in the detection of plasmid pIP501 carrying a remnant of a Tn3 family transposon. Its ability to confer HLGR was proven by transfer into an Enterococcus faecalis isolate. Conversely, loss of HLGR was documented after curing both GBS BSU452 and the transformed E. faecalis strain from the plasmid. This is the first report showing plasmid-mediated HLGR in GBS. Thus, in our clinical GBS isolates, HLGR is mediated both chromosomally and extrachromosomally.
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Molecular characterization and antimicrobial susceptibility of hemolytic Streptococcus agalactiae from post-menopausal women. Maturitas 2015; 85:5-10. [PMID: 26857873 DOI: 10.1016/j.maturitas.2015.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/07/2015] [Accepted: 11/14/2015] [Indexed: 11/24/2022]
Abstract
PURPOSE Streptococcus agalactiae (Group B streptococcus, GBS) is increasingly recognized as a pathogen in adult populations, including the elderly. Appropriate treatment involves antibiotics. An alternative to this strategy would be the administration of a polysaccharide vaccine therefore the capsular serotypes and molecular characterization of circulating strains needs to be known. Few studies have been conducted in this population. METHODS One hundred and seven GBS isolates collected from vagino-rectal swabs from 600 post-menopausal women were analysed for their capsular type, antimicrobial resistance and genetic relatedness (multilocus sequence typing, MLST). RESULTS The colonization rate was 17.8%. Capsular type III was predominant (34.6%), followed by type V (22.4%). The most frequent sequence type (ST) was 19 (23.3%), followed by 23 (18.7%), 1 (16.8%) and 17 (12.1%). Isolates were assembled into three phylogenetic groups from ST-19, ST-23 and ST-17 founders. All isolates were susceptible to penicillin, whereas resistance to erythromycin and clindamycin was recorded in 23.4% and 20.6% of isolates, respectively. CONCLUSIONS In our setting, the GBS colonization rate in postmenopausal women is similar to that reported in others populations studied. The population structure of these isolates is highly diverse and contains different STs. These data can contribute to the future development of a polysaccharide vaccine for preventing GBS infection in older adults.
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Schuab RBB, Arêas GP, Souza VC, Barros RR. Molecular epidemiology of Streptococcus agalactiae recovered from significant bacteriuria. Infect Dis (Lond) 2015; 47:637-42. [PMID: 25901729 DOI: 10.3109/23744235.2015.1040446] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Streptococcus agalactiae has been implicated in urinary tract infections, but the molecular epidemiology of such infections is poorly characterized. METHODS In this study, 194 isolates recovered from significant bacteriuria of non-pregnant individuals were submitted to antimicrobial susceptibility testing, molecular characterization of macrolide resistance, PCR-based capsular typing and analysis of genetic diversity by pulsed-field gel electrophoresis (PFGE). RESULTS By disk diffusion, all isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin; 87.6% and 9.3% of isolates were non-susceptible to tetracycline and clindamycin, respectively. The minimum inhibitory concentration (MIC) confirmed that 11.3% of isolates were resistant to erythromycin. Macrolide resistance determinants were iMLSB (n = 9), cMLSB (n = 9) and M (n = 4), associated with ermA, ermB and mefA/E. Predominant capsular types were V, Ia, II and III. No significant association was observed between any capsular type and the occurrence of pyuria. However, type III was associated with erythromycin resistance, while type II was associated with erythromycin-susceptible isolates. Distinct PFGE profiles were observed among different types, but identical profiles were found among erythromycin-susceptible and -resistant isolates of the same type. CONCLUSION A variety of capsular and PFGE types are involved in significant bacteriuria. Although capsular types found here are prevalent in different infections, the frequency of each type seems to be unique. Erythromycin resistance is due to polyclonal origin instead of the expansion of few clones of S. agalactiae.
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Affiliation(s)
- Rôde B B Schuab
- From the Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense , Rio de Janeiro , Brazil
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