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Zhang L, Kang WJ, Zhu L, Xu LJ, Guo C, Zhang XH, Liu QH, Ma L. Emergence of Invasive Serotype Ib Sequence Type 10 Group B Streptococcus Disease in Chinese Infants Is Driven by a Tetracycline-Sensitive Clone. Front Cell Infect Microbiol 2021; 11:642455. [PMID: 34055663 PMCID: PMC8162377 DOI: 10.3389/fcimb.2021.642455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/26/2021] [Indexed: 01/31/2023] Open
Abstract
Background Group B streptococcus (GBS) is a leading cause of serious infections in infants. The extensive use of tetracycline has led to the selection of specific resistant and infectious GBS clones. The sequence type (ST) 10 GBS strain, causing invasive infections in infants, is becoming prevalent in China. We aimed to understand the clinical and microbiological characteristics of this GBS strain. Methods We conducted a retrospective study on infants with invasive GBS disease from the largest women’s and children’s medical center in Shanxi and collected data between January 2017 and October 2020. GBS isolates were analyzed by capsule serotyping, genotyping, antibiotic resistance, and surface protein genes. Results All ST10 isolates belonged to serotype Ib; type Ib/ST10 strains were responsible for 66.7% (14/21, P < 0.05) of infant invasive GBS infections during the period and all resulted in late-onset (LOD) and late LOD disease (14/14). Infants with type Ib/ST10 GBS disease had significantly higher rates of meningitis (9/14, 64.3%, p < 0.05) and clinical complications (5/14, 35.7%, p < 0.05). The Ib/ST10 GBS isolates had limited genetic diversity, clustered in the CC10/bca/PI-1 + PI-2a genetic lineage, showed resistance to erythromycin, lincomycin, and fluoroquinolones and sensitivity to tetracycline, and possessed genes ermT, ermB, and amino acid changes in gyrA and parC. Conclusions The probable clonal expansion can result in severe infections in infants and ongoing emergence of multi-drug resistant isolates. Continued monitoring for type Ib/ST10 GBS infections is warranted.
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Affiliation(s)
- Li Zhang
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Wen-Juan Kang
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Lei Zhu
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Li-Jun Xu
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Chao Guo
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Xin-Hua Zhang
- Department of Neonatology Department, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Qing-Hua Liu
- Department of Pathophysiology, Shanxi Medical University, Taiyuan, China
| | - Lan Ma
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
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Motallebirad T, Fazeli H, Ghahiri A, Shokri D, Jalalifar S, Moghim S, Esfahani BN. Prevalence, population structure, distribution of serotypes, pilus islands and resistance genes among erythromycin-resistant colonizing and invasive Streptococcus agalactiae isolates recovered from pregnant and non-pregnant women in Isfahan, Iran. BMC Microbiol 2021; 21:139. [PMID: 33947330 PMCID: PMC8096152 DOI: 10.1186/s12866-021-02186-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/06/2021] [Indexed: 01/31/2023] Open
Abstract
Background The information on antibiotic resistance and molecular features of Group B Streptococcus (GBS) are essential for epidemiological purposes as well as vaccine development. Therefore, we aimed to assess the antimicrobial resistance profiles and molecular characteristics of GBS isolates in Isfahan, Iran. A total number of 72 colonizing and invasive GBS were collected from pregnant and non-pregnant women. The GBS isolates were analyzed for resistance profiles, capsular genotyping, and detection of PI-1, PI-2a, PI-2b, hvgA, ermB, ermTR, lnuB and, mefA genes. Besides, erythromycin-resistant strains were subjected to multilocus sequence typing (MLST). Results The prevalence of colonizing and invasive GBS were 11 and 0.05%, respectively. The frequency of capsular serotypes was as follows: III (26.3%), Ia (20.83%), Ib and V (each 15.2%), IV (9.7%), II (8.3%), VII (2.7%), and VI (1.3%). Overall frequencies of PIs were as follows: PI-1, 37.5%, PI-1 + PI-2a, 30.5%, PI-1 + PI-2b, 29.1% and PI-2b, 2.7%. Two maternal colonizing GBS (2.6%) were hvgA positive and were belonged to ST-17/CPS-III/PI-1 + PI-2b lineage. Among 30(41.6%) erythromycin resistant GBS, 21 isolates (70%) harbored ermB gene, followed by ermTR (23.3%) and mefA (10%). One clindamycin-resistant isolate harbored the lnuB gene. MLST analysis revealed the following five clonal complexes (CCs) and nine STs: (CC-19/ST-335, ST-19, and ST-197), (CC-12/ST-43, ST-12), (CC-23/ST-163, ST-23), (CC-17/ST-17) and (CC-4/ST-16). Conclusion The study shows an alarmingly high prevalence of erythromycin-resistant GBS in Iran. In addition, we report dissemination of ST-335/CPS-III clone associated with tetracycline and erythromycin resistance in our region. The distribution of capsular and pilus genotypes varies between invasive and colonizing GBS that could be helpful for vaccine development.
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Affiliation(s)
- Tahereh Motallebirad
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar-Jerib Street, Isfahan, Iran
| | - Hossein Fazeli
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar-Jerib Street, Isfahan, Iran
| | - Ataollah Ghahiri
- Department of Gynecology and Obstetrics, Al-Zahra university Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Dariush Shokri
- Infectious disease and tropical medicine research center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Saba Jalalifar
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar-Jerib Street, Isfahan, Iran
| | - Sharareh Moghim
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar-Jerib Street, Isfahan, Iran
| | - Bahram Nasr Esfahani
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar-Jerib Street, Isfahan, Iran.
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Nabavinia M, Khalili MB, Sadeh M, Eslami G, Vakili M, Azartoos N, Mojibiyan M. Distribution of Pilus island and antibiotic resistance genes in Streptococcus agalactiae obtained from vagina of pregnant women in Yazd, Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2020; 12:411-416. [PMID: 33603995 PMCID: PMC7867704 DOI: 10.18502/ijm.v12i5.4601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Background and Objectives: Due to the important role of Streptococcus agalactiae, Group B streptococci (GBS), in production of invasive disease in neonates, investigation regarding the pathogenicity and antibiotic resistance factors is necessary in selecting the appropriate therapeutic agents. Beside capsule, the pilus has been currently recognized as an important factor in enhancing the pathogenicity of GBS. Resistance of GBS to selected antibiotics is noticeably increasing which is mainly due to the anomalous use of these drugs for treatment. The aim of this study was to determine the prevalence of pili genes followed by antibiotic susceptibility of GBS, previously serotyped, isolated from pregnant women in the city of Yazd, Iran. Materials and Methods: Fifty seven GBS from pregnant women were subjected to multiplex PCR for determination of PI-1, PI-2a and PI-2b pilus-islands and simultaneously, the phenotype of antibiotic resistance to penicillin, tetracycline, erythromycin, clindamycin, gentamycin and levofloxacin was determined. Antibiotic resistance genes (ermA, ermB, mefA, tetM, int-Tn) were further diagnosed using PCR and multiplex PCR. Results: PI-1+PI-2a with 71.9%; followed by PI-2a (21.1%) and PI-2b (7%) were observed. PI-1+PI-2a in serotype III was (73.2%), serotype II, Ia, Ib and V were 12.2%, 9.8%, 2.4% and 2.4% respectively. GBS penicillin sensitive was 89.5% and 96.5% resistance to tetracycline. The frequency of resistance genes were as follows: tetM (93%), ermA (33.3%), ermB (8.8%), int-Tn (80.7%) and mefA (0). Conclusion: Majority of GBS contained PI-1+PI-2a. Hence presence of this pilus stabilizes the colonization, therefore designing a program for diagnosing and treatment of infected pregnant women seems to be necessary.
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Affiliation(s)
- Mahdieh Nabavinia
- Department of Microbiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mohammad Bagher Khalili
- Department of Microbiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Maryam Sadeh
- Department of Laboratory Sciences, Faculty of Paramedical Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Gilda Eslami
- Department of Parasitology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mahmood Vakili
- Department of Public Medicine, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Nastaran Azartoos
- Department of Microbiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mahdiye Mojibiyan
- Department of Obstetrics and Gynecology, Mojibiyan Hospital, Yazd, Iran
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Phylogeny, recombination, and invasiveness of group B Streptococcus revealed by genomic comparisons of its global strains. Eur J Clin Microbiol Infect Dis 2020; 40:581-590. [PMID: 33067737 PMCID: PMC7567417 DOI: 10.1007/s10096-020-04067-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 10/09/2020] [Indexed: 11/26/2022]
Abstract
Capsular polysaccharide (CPS) genes and pilus islands encode important virulence factors for group B Streptococcus (GBS) genomes. This study aims to detect phylogenetic inconsistency in CPS genes and pilus islands in GBSs and to explore its relationship with invasiveness. A total of 1016 GBS genomes were downloaded from the NCBI public database. The multi-locus sequence typing (MLST) and Bayesian analysis of Population Structure (BAPS) analyses were both conducted for phylogeny construction. Serotyping and pilus typing were determined in silico using the genomic sequences. The CPS and pilus typing results were generally consistent with MLST and BAPS clustering. GBS isolates of serotype II and of the PI-1 + PI-2b and PI-2a types were more prone to phylogenetic inconsistency than the others. Isolates of serotype Ib and of PI-1 + PI-2a were more likely to appear as colonizing strains, whereas PI-2b was more likely to appear in invasive strains. For serotype V, phylogenetic inconsistency occurred more commonly in colonizing isolates, while for serotype III, the opposite occurred. The present study profiles for the first time the phylogenetic inconsistency of CPS genes and pilus islands in global GBS isolates, which is helpful for infection control and the development of new vaccines for the prevention of GBS occurrence.
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Zhang L, Ma L, Zhu L, Zhou XH, Xu LJ, Guo C, Meng JH, Zhang XH, Liu QH, Huang R. Molecular characterization of pathogenic group B streptococcus from a tertiary hospital in Shanxi, China: High incidence of sequence type 10 strains in infants/pregnant women. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2020; 54:1094-1100. [PMID: 32826191 DOI: 10.1016/j.jmii.2020.07.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 07/12/2020] [Accepted: 07/27/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND Group B streptococcus (GBS) is a leading cause of serious infection in infants. Understanding its regional molecular epidemiology is helpful for regulating efficient prevention practice. METHODS A retrospective study was conducted to collected data from infants and pregnant women with culture-proven GBS disease in the largest women and children's medical center in Shanxi between January 2017 and September 2019. All GBS isolates were analyzed by multi-locus sequence typing (MLST) as well as distribution of pilus island (PI) genes. RESULTS A total of 54 GBS isolates were obtained from 36 (66.7%) pregnant women and 18 (33.3%) infants with invasive disease. Among invasive GBS strains, the most common sequence type was ST10 (72.2%, P < 0.05), followed by ST23 and ST19. The ST10 strain was also the leading sequence type in colonizing pregnant women (44.4%, P < 0.05). All of the isolates carried at least one pilus island. The most frequently detected pilus island was PI-1+PI-2a (85.2%, P < 0.05), followed in turn by PI-2a and PI-2b. CONCLUSIONS Our study demonstrates that one hypervirulent clone, sequence type 10, accounts for a large proportion of invasive GBS disease in infants and colonizing pregnant women, and the PI-1+PI-2a sub-lineages should be noted in infant infections.
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Affiliation(s)
- Li Zhang
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China.
| | - Lan Ma
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Lei Zhu
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Xiang-Hong Zhou
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Li-Jun Xu
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Chao Guo
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Jin-Hua Meng
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Xin-Hua Zhang
- Neonatal Department, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
| | - Qing-Hua Liu
- Department of Pathophysiology, Shanxi Medical University, Taiyuan, China
| | - Rui Huang
- Department of Clinical Laboratory, Shanxi Children's Hospital Shanxi Maternal and Child Health Hospital, Taiyuan, China
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6
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Microarray Analysis of Group B Streptococci Causing Invasive Neonatal Early- and Late-onset Infection. Pediatr Infect Dis J 2020; 39:449-453. [PMID: 32091495 DOI: 10.1097/inf.0000000000002627] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Group B Streptococcus is the leading cause of meningitis and sepsis in newborns. Until now, there is no data of fast and simple typing of group B Streptococcus virulence factors using a genetic microarray and comparing these data to clinical manifestations. METHODS A prospective active surveillance study was conducted via 2 independent and nationwide reporting systems, the German Pediatric Surveillance Unit (ESPED) and the Laboratory Sentinel Group at Robert Koch-Institute. Surveillance was performed between 2001 and 2003 and between 2008 and 2010. Typing of virulence factors, serotypes, pilus islands and alpha-like proteins was done by means of a newly developed microarray method. RESULTS We evaluated 475 isolates of invasive neonatal infections. Predominant virulence factors were serotype III (63%), pilus island 2b and pilus island 1 (50%) and alp rib (64%) (alp - alpha-like protein, rib -resistance to proteases, immunity, group B). There was no significant change over time or geographically within Germany. Serotype III, pilus island 2b + 1 and alp rib showed significant associations with late-onset disease and meningitis, whereas alp 5 had a significant association with early-onset disease. Based on serotypes, pilus islands and alpha-like proteins, it was possible to cluster 86% of all isolates into 5 genetic groups. CONCLUSIONS The molecular epidemiology of a large collection of invasive neonatal infections showed similar distributions, as shown in smaller cohorts before. The microarray used proved to be a fast and reliable technique. Using this new tool, we were able to cluster the isolates according to their virulence factors. The clusters showed a better association with clinical data than single virulence factors.
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Alvim DCSS, Ferreira AFM, Leal MA, Oliveira LMA, Botelho AMN, Botelho ACN, Figueiredo AMS, Fracalanzza SEL, Teixeira LM, Pinto TCA. Biofilm production and distribution of pilus variants among Streptococcus agalactiae isolated from human and animal sources. BIOFOULING 2019; 35:938-944. [PMID: 31646898 DOI: 10.1080/08927014.2019.1678592] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/28/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) is a major pathogen in humans and animals. Pili and biofilm may be important virulence factors in this bacterial species. Here, biofilm production and the distribution of pilus variants among 134 GBS isolates from human and animal sources were evaluated. Biofilm production was significantly enhanced in 1% glucose-supplemented medium (p < 0.05). Using this medium, most GBS strains were strong biofilm producers. Biomass was mainly composed of proteins, followed by extracellular DNA, while polysaccharides represented a minor portion. All GBS strains presented at least one pilus variant. PI-2a was the most common among human GBS while PI-2b was the most common among animal isolates. Human GBS harboring PI-2b and animal GBS harboring PI-2a presented significantly reduced biofilm production (p = 0.0033). In conclusion, strong biofilm production seems to be a common characteristic in GBS, and association of the clinical source with the pilus variant may be crucial for this.
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Affiliation(s)
| | | | - Matheus Amaral Leal
- Instituto de Microbiologia Paulo de Goes, Universidade Federal Do Rio De Janeiro, Rio De Janeiro, Brazil
| | | | - Ana Maria Nunes Botelho
- Instituto de Microbiologia Paulo de Goes, Universidade Federal Do Rio De Janeiro, Rio De Janeiro, Brazil
| | - Ana Caroline Nunes Botelho
- Instituto de Microbiologia Paulo de Goes, Universidade Federal Do Rio De Janeiro, Rio De Janeiro, Brazil
| | - Agnes Marie Sá Figueiredo
- Instituto de Microbiologia Paulo de Goes, Universidade Federal Do Rio De Janeiro, Rio De Janeiro, Brazil
| | | | - Lucia Martins Teixeira
- Instituto de Microbiologia Paulo de Goes, Universidade Federal Do Rio De Janeiro, Rio De Janeiro, Brazil
| | - Tatiana Castro Abreu Pinto
- Instituto de Microbiologia Paulo de Goes, Universidade Federal Do Rio De Janeiro, Rio De Janeiro, Brazil
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Lu B, Wu J, Chen X, Gao C, Yang J, Li Y, Wang J, Zeng J, Fang Y, Wang D, Cui Y, Wang L. Microbiological and clinical characteristics of Group B Streptococcus isolates causing materno-neonatal infections: high prevalence of CC17/PI-1 and PI-2b sublineage in neonatal infections. J Med Microbiol 2018; 67:1551-1559. [PMID: 30265233 DOI: 10.1099/jmm.0.000849] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PURPOSE Group B Streptococcus (GBS) is one of the major pathogens in severe materno-neonatal infections. We aimed to describe the clinical and molecular characteristics of GBS isolates causing infections in 45 maternal and 50 neonatal subjects, collected from eight healthcare centres in mainland China over the period 2010- 2017. METHODOLOGY The phenotypic and genotypic features of the GBS isolates, including capsular polysaccharide (cps) serotypes, pilus island (PI) genes and antibiotic resistance profiles and genes, were characterized by both conventional and molecular methods. The clonal relationship between these strains was investigated using multilocus sequence typing (MLST). RESULTS Of the 95 isolates, the predominant serotypes were III (51, 53.7 %), V (13, 13.7 %) and Ib (13, 13.7 %). All GBS strains carried at least one pilus island, with 32.6 % carrying PI-2b and 67.4 % PI-2a, singly or in combination. The most frequently-detected pilus island pattern was the combination of PI-1 and PI-2a, accounting for 56.8 % (54 isolates), followed by PI-1 combined with PI-2b (28, 29.5 %), PI-2a (10, 10.5 %) and PI-2b (3, 3.2 %). The strains were classified into 17 individual sequence types, and further clustered into six clonal complexes (CCs). A high prevalence of CC17/PI-1 and PI-2b (17, 34.0 %) was detected in 50 GBS isolates causing neonatal infections. No strain was resistant to penicillin, ampicillin, ceftriaxone or vancomycin, whereas 78.9, 76.8 and 81.5 % were resistant to erythromycin, clindamycin and tetracycline, respectively. CONCLUSION Our study highlights the high genotypic diversity of GBS strains causing materno-neonatal infections, and the CC17/PI-1 and PI-2b sublineages should be noted in neonatal infections.
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Affiliation(s)
- Binghuai Lu
- 1Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center for Respiratory Diseases, China-Japan Friendship Hospital; National Clinical Research Center of Respiratory Diseases, Beijing,100029, PR China
| | - Jianning Wu
- 2Department of Laboratory Medicine, Xiamen Maternal and Child Health Hospital, Xiamen, 361003, PR China
| | - Xingchun Chen
- 3Department of Laboratory Medicine, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, PR China
| | - Chunyan Gao
- 4Department of Laboratory Medicine, Tangshan Maternal and Child Health Care Hospital, Tangshan, 063000, PR China
| | - Junwen Yang
- 5Department of Laboratory Medicine, Zhengzhou children's hospital, Zhengzhou, 450018, PR China
| | - Yi Li
- 6Department of Laboratory Medicine, Henan Provincial People's Hospital, Zhengzhou, 450003, PR China
| | - Junrui Wang
- 7Department of clinical laboratory, Affiliated hospital of Inner Mongolia medical university, Hohhot, 010050, PR China
| | - Ji Zeng
- 8Department of Laboratory Medicine, Wuhan Pu Ai Hospital of Huazhong University of Science and Technology, Wuhan, 430034, PR China
| | - Yujie Fang
- 9National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, Beijing 102206, PR China.,10Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 310003, PR China
| | - Duochun Wang
- 9National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, Beijing 102206, PR China.,10Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 310003, PR China
| | - Yanchao Cui
- 11Department of Laboratory Medicine, Civil Aviation General Hospital, Beijing, 100123, PR China
| | - Lijun Wang
- 12Department of Laboratory Medicine, Beijing Tsinghua Chang Gung Hospital, Tsinghua University, Beijing, 102218, PR China
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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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10
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Khodaei F, Sadeghi Kalani B, Alizadeh N, Hassani A, Najafi M, Kalantar E, Amini A, Aghazadeh M. Genotyping and Phylogenetic Analysis of Group B Streptococcus by Multiple Locus Variable Number Tandem Repeat Analysis in Iran. Galen Med J 2018; 7:e1121. [PMID: 34466437 PMCID: PMC8344184 DOI: 10.22086/gmj.v0i0.1121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/08/2018] [Accepted: 03/10/2018] [Indexed: 11/30/2022] Open
Abstract
Background: Group B streptococcus (GBS), also known as Streptococcus agalactiae, is well known as a causative agent for neonatal invasive diseases; it is also a major pathogen in adults. Analytic epidemiology is required to monitor the clinical isolates of GBS. However, there is insufficient information on the genetic background of GBS in Iran, and this information is needed to guide and develop a GBS vaccine. Materials and Methods: In total, 90 well-char - acterized GBS isolates were collected from April 2014 to August 2015. In this study, molecular typing was used to disclose a relationship between the multiple-locus variable number tandem repeat analysis (MLVA) types, serotyping, and pilus islands. The isolates were characterized by the types of capsular polysaccharides and pilus islands and were examined by MLVA to study the epidemiological relationship of isolates. Results: The results indicate that there is a significant relationship between the distribution of serotypes and pilus island genes; GBS isolates were differentiated into 12 types by capsular polysaccharides and pilus islands analysis. The discriminatory power of an MLVA analysis was high based on the five most variable numbers of tandem repeat loci and 44 MLVA types that were identified. Conclusion: This study has provided useful insights into the genetic heterogeneity of GBS isolates in Tehran and Alborz, Iran. The extensive distribution of pilus islands in various serotypes and MLVA types throughout the GBS population refers to the advancement of the pilus-based GBS vaccines.
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Affiliation(s)
- Farzaneh Khodaei
- Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Naser Alizadeh
- Department of Medical Microbiology, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alka Hassani
- Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Najafi
- Department of Biochemistry, Iran University of Medical Sciences, Tehran, Iran
| | - Enayatollah Kalantar
- Department of Microbiology and Immunology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Abbas Amini
- School of Computing, Engineering and Mathematics, University of Western Sydney, Kings wood, NSW 2751, Australia
| | - Mohammad Aghazadeh
- Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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11
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Molecular characteristics of Streptococcus agalactiae in a mother-baby prospective cohort study: Implication for vaccine development and insights into vertical transmission. Vaccine 2018. [PMID: 29519594 DOI: 10.1016/j.vaccine.2018.02.109] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Streptococcus agalactiae (GBS) is a leading cause of neonatal sepsis and meningitis in many countries. This study aimed to determine the molecular characteristics of GBS colonized in mothers and their infants so as to provide implication for vaccine strategies and confirm vertical transmission. METHODS A prospective cohort study was conducted to recruit 1815 mother-neonate pairs. All GBS isolates from pregnant women and her infants were tested for serotypes, multilocus sequence types and virulence genes. The relationship between multiple molecular characteristics of GBS isolates was tested by the correspondence analysis, and the agreement between mother-neonate paired data in molecular characteristics was analyzed using Kappa tests. RESULTS The predominant serotypes were III, Ia and V, and the most prevalent sequence types (STs) were ST19, ST17, ST10, and ST12. All isolates carried at least one pilus island (PI). The most common combination of PIs was PI-2b alone, followed by PI-1+PI-2a and PI-2a alone, and the most prevalent alpha-like protein (alp) genes were rib, epsilon and alphaC. Moreover, a strong relationship was noted between STs, serotypes, alp genes and PIs, including ST17 associated with serotype-III/rib/PI-2b, ST19 with serotype-III/rib/PI-1+PI-2a, and ST485 with serotype-Ia/epsilon/PI-2b. The rate of GBS vertical transmission was 14.1%, and the kappa test revealed good agreement in multiple molecular characteristics among GBS-positive mother-neonate pairs. Notably, the switching of molecular characteristics was found during vertical transmission. CONCLUSIONS Our findings underscore the value of monitoring multiple molecular characteristics so as to provide implication for multivalent strategies and gain insights into GBS vertical transmission and vertical characteristic switching.
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12
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Li L, Wang R, Huang Y, Huang T, Luo F, Huang W, Yang X, Lei A, Chen M, Gan X. High Incidence of Pathogenic Streptococcus agalactiae ST485 Strain in Pregnant/Puerperal Women and Isolation of Hyper-Virulent Human CC67 Strain. Front Microbiol 2018; 9:50. [PMID: 29467722 PMCID: PMC5808242 DOI: 10.3389/fmicb.2018.00050] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 01/10/2018] [Indexed: 01/02/2023] Open
Abstract
Group B streptococcus (GBS) is the major pathogen causing diseases in neonates, pregnant/puerperal women, cows and fish. Recent studies have shown that GBS may be infectious across hosts and some fish GBS strain might originate from human. The purpose of this study is to investigate the genetic relationship of CC103 strains that recently emerged in cows and humans, and explore the pathogenicity of clinical GBS isolates from human to tilapia. Ninety-two pathogenic GBS isolates were identified from 19 patients with different diseases and their evolution and pathogenicity to tilapia were analyzed. The multilocus sequence typing revealed that clonal complex (CC) 103 strain was isolated from 21.74% (20/92) of patients and ST485 strain was from 14.13% (13/92) patients with multiple diseases including neonates. Genomic evolution analysis showed that both bovine and human CC103 strains alternately form independent evolutionary branches. Three CC67 isolates carried gbs2018-C gene and formed one evolutionary branch with ST61 and ST67 strains that specifically infect dairy cows. Studies of interspecies transmission to tilapia found that 21/92 (22.83%) isolates including all ST23 isolates were highly pathogenic to tilapia and demonstrated that streptococci could break through the blood-brain barrier into brain tissue. In conclusions, CC103 strains are highly prevalent among pathogenic GBS from humans and have evolved into the highly pathogenic ST485 strains specifically infecting humans. The CC67 strains isolated from cows are able to infect humans through evolutionary events of acquiring CC17-specific type C gbs2018 gene and others. Human-derived ST23 pathogenic GBS strains are highly pathogenic to tilapia.
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Affiliation(s)
- Liping Li
- Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fisheries, Nanning, China.,Bacteria Laboratory, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Rui Wang
- Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fisheries, Nanning, China.,Institute of Animal Science and Technology, Guangxi University, Nanning, China
| | - Yan Huang
- Bacteria Laboratory, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Ting Huang
- Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fisheries, Nanning, China
| | - Fuguang Luo
- Liuzhou's Aquaculture Technology Extending Station, Liuzhou, China
| | - Weiyi Huang
- Institute of Animal Science and Technology, Guangxi University, Nanning, China
| | - Xiuying Yang
- School of Public Health, National Medical College of Right Rivers, Baise, China
| | - Aiying Lei
- Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fisheries, Nanning, China
| | - Ming Chen
- Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fisheries, Nanning, China.,Bacteria Laboratory, Guangxi Center for Disease Control and Prevention, Nanning, China.,Institute of Animal Science and Technology, Guangxi University, Nanning, China
| | - Xi Gan
- Guangxi Key Laboratory for Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Institute of Fisheries, Nanning, China
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13
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Khodaei F, Najafi M, Hasani A, Kalantar E, Sharifi E, Amini A, Aghazadeh M. Pilus-encoding islets in S. agalactiae and its association with antibacterial resistance and serotype distribution. Microb Pathog 2018; 116:189-194. [PMID: 29371153 DOI: 10.1016/j.micpath.2018.01.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 10/11/2017] [Accepted: 01/19/2018] [Indexed: 11/28/2022]
Abstract
Group B Streptococcus (GBS) is a versatile organism which uses multiple virulence factors which bind to the surface of epithelial cells. Pili are one of virulence factors detected in recent years. A total of 90 isolates were collected from invasive and non-invasive isolates among adults throughout 2014-2015. Isolates were serotyped at molecular level based on capsular polysaccharide (cps) serotyping and analyzed for pilus island profiles, scpB gene, and hvgA gene presence. Isolates were subjected to antimicrobial susceptibility towards penicillin, tetracycline, erythromycin, clindamycin, moxifloxacin, levofloxacin, and vancomycin by disk diffusion method and MICs for erythromycin and clindamycin were determined by broth dilution methods. Overall, 4 serotypes were identified, serotype III (68.88%), V (20%), II (10%) and Ib (1.11%) and hvgA gene was detected in 7.7% (n = 7) of the isolates; all were serotype III/ST 17. All isolates were susceptible to penicillin and vancomycin, except one isolate which showed intermediate resistance to penicillin and other complete resistance to vancomycin. Isolates were resistant to tetracycline (98%), erythromycin (25%), clindamycin (22%), moxifloxacin (8%), and levofloxacin (6%). The scpB gene was detected in all isolates, while isolates harbored at least one PI, of which the PI-1+PI-2a was the most frequent combination observed. Our data show the presence of the relation between serotype or pilus genes among clinical isolates of Streptococcus agalactiae. These data are principal to help in designing prevention and treatment strategies for GBS infections in the region.
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Affiliation(s)
- Farzaneh Khodaei
- Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Najafi
- Department of Biochemistry, Iran University of Medical Sciences, Tehran, Iran
| | - Alka Hasani
- Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Enayatollah Kalantar
- Department of Microbiology and Immunology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | | | - Abbas Amini
- School of Computing, Engineering and Mathematics, University of Western Sydney, Kingswood, NSW 2751, Australia
| | - Mohammad Aghazadeh
- Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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14
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Périchon B, Szili N, du Merle L, Rosinski-Chupin I, Gominet M, Bellais S, Poyart C, Trieu-Cuot P, Dramsi S. Regulation of PI-2b Pilus Expression in Hypervirulent Streptococcus agalactiae ST-17 BM110. PLoS One 2017; 12:e0169840. [PMID: 28107386 PMCID: PMC5249243 DOI: 10.1371/journal.pone.0169840] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/22/2016] [Indexed: 11/19/2022] Open
Abstract
The widely spread Streptococcus agalactiae (also known as Group B Streptococcus, GBS) “hypervirulent” ST17 clone is strongly associated with neonatal meningitis. The PI-2b locus is mainly found in ST17 strains but is also present in a few non ST17 human isolates such as the ST-7 prototype strain A909. Here, we analysed the expression of the PI-2b pilus in the ST17 strain BM110 as compared to the non ST17 A909. Comparative genome analyses revealed the presence of a 43-base pair (bp) hairpin-like structure in the upstream region of PI-2b operon in all 26 ST17 genomes, which was absent in the 8 non-ST17 strains carrying the PI-2b locus. Deletion of this 43-bp sequence in strain BM110 resulted in a 3- to 5-fold increased transcription of PI-2b. Characterization of PI-2b promoter region in A909 and BM110 strains was carried out by RNAseq, primer extension, qRT-PCR and transcriptional fusions with gfp as reporter gene. Our results indicate the presence of a single promoter (Ppi2b) with a transcriptional start site (TSS) mapped 37 bases upstream of the start codon of the first PI-2b gene. The large operon of 16 genes located upstream of PI-2b codes for the group B carbohydrate (also known as antigen B), a major constituent of the bacterial cell wall. We showed that the hairpin sequence located between antigen B and PI-2b operons is a transcriptional terminator. In A909, increased expression of PI-2b probably results from read-through transcription from antigen B operon. In addition, we showed that an extended 5’ promoter region is required for maximal transcription of gfp as a reporter gene in S. agalactiae from Ppi2b promoter. Gene reporter assays performed in Lactococcus lactis strain NZ9000, a related non-pathogenic Gram-positive species, revealed that GBS-specific regulatory factors are required to drive PI-2b transcription. PI-2b expression is up-regulated in the BM110ΔcovR mutant as compared to the parental BM110 strain, but this effect is probably indirect. Collectively, our results indicate that PI-2b expression is regulated in GBS ST17 strains, which may confer a selective advantage in the human host either by reducing host immune responses and/or increasing their dissemination potential.
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Affiliation(s)
- Bruno Périchon
- Institut Pasteur, Biology of Gram-positive Pathogens Unit, Paris, France
- Centre National de la Recherche Scientifique (CNRS) ERL3526, Paris, France
| | - Noémi Szili
- Institut Pasteur, Biology of Gram-positive Pathogens Unit, Paris, France
- Centre National de la Recherche Scientifique (CNRS) ERL3526, Paris, France
| | - Laurence du Merle
- Institut Pasteur, Biology of Gram-positive Pathogens Unit, Paris, France
- Centre National de la Recherche Scientifique (CNRS) ERL3526, Paris, France
| | | | - Myriam Gominet
- Institut Pasteur, Biology of Gram-positive Pathogens Unit, Paris, France
- Centre National de la Recherche Scientifique (CNRS) ERL3526, Paris, France
| | - Samuel Bellais
- Équipe Barrières et Pathogènes, Institut Cochin, Inserm 1016, CNRS UMR, Paris France
- Assistance Publique-Hôpitaux de Paris, Hôpitaux Universitaires Paris Centre-Site Cochin, France
| | - Claire Poyart
- Équipe Barrières et Pathogènes, Institut Cochin, Inserm 1016, CNRS UMR, Paris France
- Assistance Publique-Hôpitaux de Paris, Hôpitaux Universitaires Paris Centre-Site Cochin, France
- CNR Streptocoques, Hôpitaux Universitaires Paris Centre, site Cochin, AP-HP
- DHU Risques et Grossesse, AP-HP, Paris, France
| | - Patrick Trieu-Cuot
- Institut Pasteur, Biology of Gram-positive Pathogens Unit, Paris, France
- Centre National de la Recherche Scientifique (CNRS) ERL3526, Paris, France
| | - Shaynoor Dramsi
- Institut Pasteur, Biology of Gram-positive Pathogens Unit, Paris, France
- Centre National de la Recherche Scientifique (CNRS) ERL3526, Paris, France
- * E-mail:
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15
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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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16
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Clonal Complex 17 Group B Streptococcus strains causing invasive disease in neonates and adults originate from the same genetic pool. Sci Rep 2016; 6:20047. [PMID: 26843175 PMCID: PMC4740736 DOI: 10.1038/srep20047] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/23/2015] [Indexed: 11/20/2022] Open
Abstract
A significant proportion of group B Streptococcus (GBS) neonatal disease, particularly late-onset disease, is associated with strains of serotype III, clonal complex (CC) 17. CC17 strains also cause invasive infections in adults. Little is known about the phylogenetic relationships of isolates recovered from neonatal and adult CC17 invasive infections. We performed whole-genome-based phylogenetic analysis of 93 temporally and geographically matched CC17 strains isolated from both neonatal and adult invasive infections in the metropolitan region of Toronto/Peel, Canada. We also mined the whole-genome data to reveal mobile genetic elements carrying antimicrobial resistance genes. We discovered that CC17 GBS strains causing neonatal and adult invasive disease are interspersed and cluster tightly in a phylogenetic tree, signifying that they are derived from the same genetic pool. We identified limited variation due to recombination in the core CC17 genome. We describe that loss of Pilus Island 1 and acquisition of different mobile genetic elements carrying determinants of antimicrobial resistance contribute to CC17 genetic diversity. Acquisition of some of these mobile genetic elements appears to correlate with clonal expansion of the strains that possess them. Our results provide a genome-wide portrait of the population structure and evolution of a major disease-causing clone of an opportunistic pathogen.
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17
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Dangor Z, Kwatra G, Izu A, Adrian P, Cutland CL, Velaphi S, Ballot D, Reubenson G, Zell ER, Lala SG, Madhi SA. Association between maternal Group B Streptococcus surface-protein antibody concentrations and invasive disease in their infants. Expert Rev Vaccines 2015; 14:1651-60. [PMID: 26364978 DOI: 10.1586/14760584.2015.1085307] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Group B Streptococcus (GBS) surface-proteins have been shown to be immunogenic and potential vaccine candidates. We aim to determine the association between maternal IgG antibodies to select GBS surface-proteins and invasive GBS disease in their infants. METHODS Using a matched case-control study, maternal antibody levels for GBS-immunogenic bacterial adhesin, fibrinogen-binding protein A and pilus-island (PI) PI-1, PI-2a, PI-2b were compared between infants with invasive GBS disease and well-baby controls. RESULTS The absolute risk of disease did not differ between cases and colonized controls with increasing antibody concentrations for these surface-proteins. There was, however, a relative risk reduction in invasive disease associated with fibrinogen-binding protein A, with an adjusted odds ratio of 0.04 (95% CI: 0.01-0.69) at antibody levels ≥10,000 AU/ml. CONCLUSION We have not demonstrated an association between naturally occurring fibrinogen-binding protein A, GBS-immunogenic bacterial adhesin, and PI surface-protein antibodies and the risk of invasive disease in young infants. These surface-proteins may not be suitable GBS vaccine candidates.
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Affiliation(s)
- Ziyaad Dangor
- a 1 Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,b 2 Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,c 3 Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gaurav Kwatra
- a 1 Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,b 2 Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Alane Izu
- a 1 Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,b 2 Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Peter Adrian
- a 1 Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,b 2 Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Clare L Cutland
- a 1 Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,b 2 Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sithembiso Velaphi
- c 3 Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Daynia Ballot
- c 3 Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gary Reubenson
- c 3 Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Sanjay G Lala
- c 3 Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- a 1 Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,b 2 Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,e 5 National Institute for Communicable Diseases: a division of National Health Laboratory Service, Centre for Vaccines and Immunology, Sandringham, South Africa
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18
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Lu B, Wang D, Zhou H, Zhu F, Li D, Zhang S, Shi Y, Cui Y, Huang L, Wu H. Distribution of pilus islands and alpha-like protein genes of group B Streptococcus colonized in pregnant women in Beijing, China. Eur J Clin Microbiol Infect Dis 2015; 34:1173-9. [PMID: 25669160 DOI: 10.1007/s10096-015-2342-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/27/2015] [Indexed: 11/30/2022]
Abstract
Group B Streptococcus (GBS) is one of the major pathogens of severe newborn sepsis and meningitis. Understanding its regional molecular epidemiology is helpful for regulating efficient prevention practice. A total of 160 GBS strains were collected from colonized pregnant women in six hospital settings in Beijing, China. Polymerase chain reaction (PCR) assays were used to identify the pilus island (PI), alp genes profiling of the alpha-like protein family, and capsular polysaccharide (cps) serotyping. The clonal relationships between strains were investigated using multilocus sequence typing (MLST). All isolates carried at least one pilus island. The most frequently detected pilus island was PI-2a alone (70 isolates, 43.8 %). The most prevalent alp gene was rib (60 isolates, 37.5 %). Moreover, a strong association was noted between alp genes, serotyping, and pilus island profiles. The GBS isolates under study hinted similar molecular epidemical characteristics in Beijing to those reported worldwide, but having their regional distributional features.
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Affiliation(s)
- B Lu
- Department of Laboratory Medicine, Civil Aviation General Hospital, No. 1 Gaojing Street, Chaoyang District, Beijing, 100123, People's Republic of China,
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19
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Le Doare K, Allen L, Kampmann B, Heath PT, Taylor S, Hesseling AC, Gorringe A, Jones CE. Anti-group B Streptococcus antibody in infants born to mothers with human immunodeficiency virus (HIV) infection. Vaccine 2014; 33:621-7. [PMID: 25543061 PMCID: PMC4315133 DOI: 10.1016/j.vaccine.2014.12.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 12/10/2014] [Accepted: 12/12/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND HIV-exposed uninfected infants have increased infection risk and mortality compared to HIV-unexposed infants. HIV-exposed infants may be at increased risk of invasive GBS disease due to reduced maternal antibody against GBS. METHODS We quantified antibodies that bind to the surface of whole Group B Streptococcus (GBS) of serotypes Ia, Ib, II, III and V using novel flow cytometry assays in South African HIV-infected and non-infected mothers and their uninfected infants. Antibody-mediated complement C3b/iC3b deposition onto GBS of these serotypes was also quantified by a novel flow cytometry assay. RESULTS Geometric mean concentration (GMC) of both surface-binding anti-GBS antibody and antibody-mediated complement deposition onto GBS were reduced in HIV-infected women (n=46) compared to HIV-uninfected women (n=58) for ST1a (surface-binding: 19.3 vs 29.3; p=0.003; complement deposition: 2.9 vs 5.3 SU/mL; p=0.003), STIb (24.9 vs 47.6; p=0.003; 2.6 vs 4.9 SU/mL; p=0.003), STII (19.8 vs 50.0; p=0.001; 3.1 vs 6.2 SU/mL; p=0.001), STIII (27.8 vs 60.1; p=0.001; 2.8 vs 5.3 SU/mL; p=0.001) and STV (121.9 vs 185.6 SU/mL; p<0.001) and in their infants for STIa (complement deposition 9.4 vs 27.0 SU/mL; p=0.02), STIb (13.4 vs 24.5 SU/mL; p=0.02), STII (14.6 vs 42.7 SU/mL; p=0.03), STIII (26.6 vs 62.7 SU/mL; p=0.03) and STV (90.4 vs 165.8 SU/mL; p=0.04). Median transplacental transfer of antibody from HIV-infected women to their infants was reduced compared to HIV-uninfected women for GBS serotypes II (0.42 [IQR 0.22-0.59] vs 1.0 SU/mL [0.42-1.66]; p<0.001), III (0.54 [0.31-1.03] vs 0.95 SU/mL [0.42-3.05], p=0.05) and V (0.51 [0.28-0.79] vs 0.75 SU/mL [0.26-2.9], p=0.04). The differences between infants remained significant at 16 weeks of age. CONCLUSIONS Maternal HIV infection was associated with lower anti-GBS surface binding antibody concentration and antibody-mediated C3b/iC3b deposition onto GBS bacteria of serotypes Ia, Ib, II, III and V. This may render these infants more susceptible to early and late onset GBS disease.
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Affiliation(s)
- Kirsty Le Doare
- Wellcome Trust/Imperial Centre for Global Health Research/Department of Academic Paediatrics, Imperial College London, Norfolk Place, London W2 1NY, UK; Paediatric Infectious Diseases Research Group, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK.
| | - Lauren Allen
- Public Health England, Porton Down, Salisbury SP4 0JG, UK
| | - Beate Kampmann
- Wellcome Trust/Imperial Centre for Global Health Research/Department of Academic Paediatrics, Imperial College London, Norfolk Place, London W2 1NY, UK; Medical Research Council, Atlantic Road, Fajara, Gambia
| | - Paul Trafford Heath
- Paediatric Infectious Diseases Research Group, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Stephen Taylor
- Public Health England, Porton Down, Salisbury SP4 0JG, UK
| | - Anneke C Hesseling
- Desmond Tutu TB Center, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | | | - Christine Elizabeth Jones
- Wellcome Trust/Imperial Centre for Global Health Research/Department of Academic Paediatrics, Imperial College London, Norfolk Place, London W2 1NY, UK; Paediatric Infectious Diseases Research Group, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK; Desmond Tutu TB Center, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
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Nawrocki KL, Crispell EK, McBride SM. Antimicrobial Peptide Resistance Mechanisms of Gram-Positive Bacteria. Antibiotics (Basel) 2014; 3:461-92. [PMID: 25419466 PMCID: PMC4239024 DOI: 10.3390/antibiotics3040461] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 09/25/2014] [Accepted: 09/28/2014] [Indexed: 01/09/2023] Open
Abstract
Antimicrobial peptides, or AMPs, play a significant role in many environments as a tool to remove competing organisms. In response, many bacteria have evolved mechanisms to resist these peptides and prevent AMP-mediated killing. The development of AMP resistance mechanisms is driven by direct competition between bacterial species, as well as host and pathogen interactions. Akin to the number of different AMPs found in nature, resistance mechanisms that have evolved are just as varied and may confer broad-range resistance or specific resistance to AMPs. Specific mechanisms of AMP resistance prevent AMP-mediated killing against a single type of AMP, while broad resistance mechanisms often lead to a global change in the bacterial cell surface and protect the bacterium from a large group of AMPs that have similar characteristics. AMP resistance mechanisms can be found in many species of bacteria and can provide a competitive edge against other bacterial species or a host immune response. Gram-positive bacteria are one of the largest AMP producing groups, but characterization of Gram-positive AMP resistance mechanisms lags behind that of Gram-negative species. In this review we present a summary of the AMP resistance mechanisms that have been identified and characterized in Gram-positive bacteria. Understanding the mechanisms of AMP resistance in Gram-positive species can provide guidelines in developing and applying AMPs as therapeutics, and offer insight into the role of resistance in bacterial pathogenesis.
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Affiliation(s)
- Kathryn L Nawrocki
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322, USA; (K.L.N.); (E.K.C.)
| | - Emily K Crispell
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322, USA; (K.L.N.); (E.K.C.)
| | - Shonna M McBride
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322, USA; (K.L.N.); (E.K.C.)
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21
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Kwatra G, Adrian PV, Shiri T, Buchmann EJ, Cutland CL, Madhi SA. Serotype-specific acquisition and loss of group B streptococcus recto-vaginal colonization in late pregnancy. PLoS One 2014; 9:e98778. [PMID: 24979575 PMCID: PMC4076185 DOI: 10.1371/journal.pone.0098778] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 05/06/2014] [Indexed: 12/04/2022] Open
Abstract
Background Maternal recto-vaginal colonization with Group B Streptococcus (GBS) and consequent vertical transmission to the newborn predisposes neonates to early-onset invasive GBS disease. This study aimed to determine the acquisition and loss of serotype-specific recto-vaginal GBS colonization from 20–37+ weeks of gestational age. Methods Vaginal and rectal swabs were collected from HIV-uninfected women at 20–25 weeks of gestation age and at 5–6 weekly intervals thereafter. Swabs were cultured for GBS and isolates were serotyped by latex agglutination. Serologically non-typable isolates and pilus islands were characterized by PCR. Results The prevalence of recto-vaginal GBS colonization was 33.0%, 32.7%, 28.7% and 28.4% at 20–25 weeks, 26–30 weeks, 31–35 weeks and 37+ weeks of gestational age, respectively. The most common identified serotypes were Ia (39.2%), III (32.8%) and V (12.4%). Of 507 participants who completed all four study visits, the cumulative overall recto-vaginal acquisition rate of new serotypes during the study was 27.9%, including 11.2%, 8.2% and 4.3% for serotypes Ia, III and V, respectively. Comparing the common colonizing serotypes, serotype III was more likely to be associated with persistent colonization throughout the study (29%) than Ia (18%; p = 0.045) or V (6%; p = 0.002). The median duration of recto-vaginal GBS colonization for serotype III was 6.35 weeks, which was longer than other serotypes. Pilus island proteins were detected in all GBS isolates and their subtype distribution was associated with specific serotypes. Conclusion South African pregnant women have a high prevalence of GBS recto-vaginal colonization from 20 weeks of gestational age onwards, including high GBS acquisition rates in the last pregnancy-trimesters. There are differences in specific-serotype colonization patterns during pregnancy.
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Affiliation(s)
- Gaurav Kwatra
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
- MRC, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Peter V. Adrian
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
- MRC, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
- * E-mail:
| | - Tinevimbo Shiri
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
- MRC, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Eckhart J. Buchmann
- Department of Obstetrics and Gynaecology, University of the Witwatersrand, Johannesburg, South Africa
| | - Clare L. Cutland
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
- MRC, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A. Madhi
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
- MRC, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
- National Institute for Communicable Diseases: a division of National Health Laboratory Service, Johannesburg, South Africa
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22
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Springman AC, Lacher DW, Waymire EA, Wengert SL, Singh P, Zadoks RN, Davies HD, Manning SD. Pilus distribution among lineages of group b streptococcus: an evolutionary and clinical perspective. BMC Microbiol 2014; 14:159. [PMID: 24943359 PMCID: PMC4074840 DOI: 10.1186/1471-2180-14-159] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/13/2014] [Indexed: 12/19/2022] Open
Abstract
Background Group B Streptococcus (GBS) is an opportunistic pathogen in both humans and bovines. Epidemiological and phylogenetic analyses have found strains belonging to certain phylogenetic lineages to be more frequently associated with invasive newborn disease, asymptomatic maternal colonization, and subclinical bovine mastitis. Pilus structures in GBS facilitate colonization and invasion of host tissues and play a role in biofilm formation, though few large-scale studies have estimated the frequency and diversity of the three pilus islands (PIs) across diverse genotypes. Here, we examined the distribution of pilus islands (PI) 1, 2a and 2b among 295 GBS strains representing 73 multilocus sequence types (STs) belonging to eight clonal complexes. PCR-based RFLP was also used to evaluate variation in the genes encoding pilus backbone proteins of PI-2a and PI-2b. Results All 295 strains harbored one of the PI-2 variants and most human-derived strains contained PI-1. Bovine-derived strains lacked PI-1 and possessed a unique PI-2b backbone protein allele. Neonatal strains more frequently had PI-1 and a PI-2 variant than maternal colonizing strains, and most CC-17 strains had PI-1 and PI-2b with a distinct backbone protein allele. Furthermore, we present evidence for the frequent gain and loss of genes encoding certain pilus types. Conclusions These data suggest that pilus combinations impact host specificity and disease presentation and that diversification often involves the loss or acquisition of PIs. Such findings have implications for the development of GBS vaccines that target the three pilus islands.
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Affiliation(s)
| | | | | | | | | | | | | | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA.
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23
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Usein CR, Militaru M, Cristea V, Străuţ M. Genetic diversity and antimicrobial resistance in Streptococcus agalactiae strains recovered from female carriers in the Bucharest area. Mem Inst Oswaldo Cruz 2014; 109:189-96. [PMID: 24676662 PMCID: PMC4015262 DOI: 10.1590/0074-0276140431] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 01/29/2014] [Indexed: 11/23/2022] Open
Abstract
For the first time, we used multilocus sequence typing (MLST) to understand how
Romanian group B streptococcus (GBS) strains fit into the global GBS population
structure. Colonising isolates recovered from adult human females were tested for
antibiotic resistance, were molecularly serotyped based on the capsular
polysaccharide synthesis (cps) gene cluster and further
characterised using a set of molecular markers (surface protein genes, pilus-encoded
islands and mobile genetic elements inserted in the scpB-lmb
intergenic region). Pulsed-field gel electrophoresis was used to complement the MLST
clonal distribution pattern of selected strains. Among the 55 strains assigned to six
cps types (Ia, Ib, II-V), 18 sequence types (STs) were identified
by MLST. Five STs represented new entries to the MLST database. The prevalent STs
were ST-1, ST-17, ST-19 and ST-28. Twenty molecular marker profiles were identified.
The most common profiles (rib+GBSi1+PI-1,
rib+GBSi1+PI-1, PI-2b and alp2/3+PI-1, PI-2a) were
associated with the cps III/ST-17 and cps V/ST-1
strains. A cluster of fluoroquinolone-resistant strains was detected among the
cps V/ST-19 members; these strains shared alp1
and IS1548 and carried PI-1, PI-2a or both. Our results
support the usefulness of implementing an integrated genotyping system at the
reference laboratory level to obtain the reliable data required to make comparisons
between countries.
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Affiliation(s)
- Codruţa-Romaniţa Usein
- Molecular Epidemiology Laboratory, Cantacuzino National Institute of Research/Development for Microbiology and Immunology, Bucharest, Romania
| | - Mădălina Militaru
- Molecular Epidemiology Laboratory, Cantacuzino National Institute of Research/Development for Microbiology and Immunology, Bucharest, Romania
| | | | - Monica Străuţ
- Molecular Epidemiology Laboratory, Cantacuzino National Institute of Research/Development for Microbiology and Immunology, Bucharest, Romania
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24
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Otaguiri ES, Morguette AEB, Tavares ER, dos Santos PMC, Morey AT, Cardoso JD, Perugini MRE, Yamauchi LM, Yamada-Ogatta SF. Commensal Streptococcus agalactiae isolated from patients seen at University Hospital of Londrina, Paraná, Brazil: capsular types, genotyping, antimicrobial susceptibility and virulence determinants. BMC Microbiol 2013; 13:297. [PMID: 24359590 PMCID: PMC3878097 DOI: 10.1186/1471-2180-13-297] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 12/16/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Streptococcus agalactiae or Group B Streptococci (GBS) have the ability to access various host sites, which reflects its adaptability to different environments during the course of infection. This adaptation is due to the expression of virulence factors that are involved with survival, invasion and bacterial persistence in the host. This study aimed to characterize GBS isolates from women of reproductive age seen at University Hospital of Londrina, according to capsular typing, genetic relatedness, antimicrobial susceptibility profile and occurrence of virulence determinants. RESULTS A total of 83 GBS isolates were enrolled in this study. Capsular types Ia (42.2%), II (10.8%), III (14.5%) and V (30.1%) were identified in most GBS. One isolate each was classified as type IX and non-typeable.A total of 15 multiple locus variable number of tandem repeat analysis (MLVA) types were identified among the isolates, seven were singletons and eight were represented by more than four isolates. All isolates were susceptible to penicillin, ampicillin, cefepime, cefotaxime, chloramphenicol, levofloxacin and vancomycin. Resistance to erythromycin and clindamycin was observed in 19.3 and 13.3% of isolates, respectively. All isolates resistant to clindamycin were simultaneously resistant to erythromycin and were distributed in the capsular types III and V. One isolate showed the constitutive macrolide-lincosamide-streptogramin B (cMLS(B)) phenotype and ten showed the inducible MLS(B) (iMLS(B)) phenotype. The mechanism of resistance to erythromycin and clindamycin more prevalent among these isolates was mediated by the gene ermA, alone or in combination with the gene ermB. The isolates displaying resistance only to erythromycin belonged to capsular type Ia, and showed the M phenotype, which was mediated by the mefA/E gene. All isolates harbored the gene hylB and at least one pilus variant, PI-1, PI-2a or PI-2b. Although cylE was observed in all GBS, four isolates were classified as gamma-hemolytic and carotenoid pigment non-producers. CONCLUSIONS Our results indicate the potential virulence of commensal GBS isolates, reinforcing the need for continued screening for this bacterium to prevent infections. The distribution of capsular and pili antigens, and MLVA profiles was also identified, which may contribute to the development of new strategies for the prevention and treatment of GBS infection.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Sueli Fumie Yamada-Ogatta
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, PR 445, km 380, Londrina, Paraná, CEP 86057-970, Brazil.
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