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BMC Microbiology Feb 2013In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an...
BACKGROUND
In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans.
METHODS
Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements.
RESULTS
Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans.
CONCLUSIONS
The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S. agalactiae strains.
Topics: Animals; Anura; Asia; Cluster Analysis; Fishes; Genotype; Mammals; Molecular Epidemiology; Molecular Typing; Streptococcal Infections; Streptococcus agalactiae
PubMed: 23419028
DOI: 10.1186/1471-2180-13-41 -
BMC Genomics Sep 2018Streptococcus agalactiae (Group B Streptococcus, GBS) is a common bacteria species infecting both human and bovine. Previous studies have shown that the GBS isolated... (Comparative Study)
Comparative Study
BACKGROUND
Streptococcus agalactiae (Group B Streptococcus, GBS) is a common bacteria species infecting both human and bovine. Previous studies have shown that the GBS isolated from human and bovine are mostly unrelated and belong to separate populations. However, recently, the bovine GBS CC103 has become the dominant epidemic strain and frequently isolated from human patients. In particular, the ST485 GBS, a member of CC103, has become the new dominant ST in China and exhibited very high pathogenicity. This phenomenon is not consistent with the established understanding about the relationship between bovine and human GBS, which needs to be re-investigated.
RESULTS
The genome-based phylogenetic analysis showed that the human and bovine GBS CC103 strains had very close genetic relationship and they were alternately distributed on the evolutionary tree. CC103 strains evolved into several branches, including the ST485, which exhibited high pathogenicity and specifically infected human. Compared to other CC103 strains, the ST485 lacked Lac.2 gene structure and acquired the CadDX gene structure in their genomes.
CONCLUSIONS
Our results indicate that GBS CC103 could propagate across human and bovine, and GBS ST485 might evolve from the ST103 that could infect both human and bovine. Moreover, the recombination of Lac.2 and CadDX gene structures might play an important role in the formation of highly pathogenic ST485 in China.
Topics: Animals; Cattle; Cattle Diseases; China; Evolution, Molecular; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Humans; Phylogeny; Recombination, Genetic; Sequence Analysis, DNA; Streptococcal Infections; Streptococcus agalactiae
PubMed: 30261834
DOI: 10.1186/s12864-018-5084-0 -
Infection, Genetics and Evolution :... Jun 2020Streptococcus agalactiae are important pathogenic bacteria that cause severe infections in humans, especially neonates. The mechanism by which ST-17 causes invasive...
Streptococcus agalactiae are important pathogenic bacteria that cause severe infections in humans, especially neonates. The mechanism by which ST-17 causes invasive infections than other STs is not well understood. In this study, we sequenced the first genome of a S. agalactiae ST-17 strain isolated in Brazil using the Illumina HiSeq 2500 technology. S. agalactiae GBS90356 ST-17 belongs to the capsular type III and was isolated from a neonatal with a fatal case of meningitis. The genome presented a size of 2.03 Mbp and a G + C content of 35.2%. S. agalactiae has 706 genes in its core genome and an open pan-genome with a size of 5.020 genes, suggesting a high genomic plasticity. GIPSy software was used to identify 10 Pathogenicity islands (PAIs) which corresponded to 15% of the genome size. IslandViewer4 corroborated the prediction of six PAIs. The pathogenicity islands showed important virulence factors genes for S. agalactiae e.g. neu, cps, dlt, fbs, cfb, lmb. SignalP detected 20 proteins with signal peptides among the 352 proteins found in PAIs, which 60% were located in the SagPAI_5. SagPAI_2 and 5 were mainly detected in ST-17 strains studied. Moreover, we identified 51 unique genes, 9 recombination regions and a large number of SNPs with an average of 760.3 polymorphisms, which can be related with high genomic plasticity and virulence during host-pathogen interactions. Our results showed implications for pathogenesis, evolution, concept of species and in silico analysis value to understand the epidemiology and genome plasticity of S. agalactiae.
Topics: Brazil; Computational Biology; Genome, Bacterial; Genomics; Humans; Molecular Sequence Annotation; Phylogeny; Public Health Surveillance; Streptococcal Infections; Streptococcus agalactiae; Virulence; Virulence Factors
PubMed: 31954181
DOI: 10.1016/j.meegid.2020.104195 -
European Journal of Clinical... Mar 2018Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults,...
Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373 S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains were identified that were spread across different continents and/or were present in more than one host species. In particular, several strains were detected in both humans and cattle, and several canine strains were also detected in samples from human, bovine, and porcine hosts. The findings of our study suggest that although S. agalactiae is well adapted to various hosts including humans, cattle, dogs, rodents, and fish, interspecies transmission is possible and occurs between humans and cows, dogs, and rabbits. The virulence and resistance gene profiles presented enable new insights into interspecies transmission and make a crucial contribution to the identification of suitable targets for therapeutic agents and vaccines.
Topics: Animals; Bacterial Proteins; Cattle; DNA, Bacterial; Dogs; Humans; Oligonucleotide Array Sequence Analysis; Streptococcal Infections; Streptococcus agalactiae; Swine; Virulence
PubMed: 29181634
DOI: 10.1007/s10096-017-3146-x -
PloS One 2018The objectives of this study were to: (a) genotypically characterize Streptococcus agalactiae isolates recovered from clinical mastitis (CM) cases in dairy cows and, (b)...
The objectives of this study were to: (a) genotypically characterize Streptococcus agalactiae isolates recovered from clinical mastitis (CM) cases in dairy cows and, (b) determine the association of antimicrobial susceptibility (AMS) and genotypes of Strep. agalactiae clustered according to the genetic similarity. A total of 89 Strep. agalactiae isolates recovered from bovine CM were genotyped using random amplified polymorphic DNA (RAPD) analysis. In addition, the AMS of the isolates was determined using a commercial broth microdilution test composed of 10 antimicrobials (penicillin, ampicillin, oxacillin, cephalothin, ceftiofur, penicillin/novobiocin, erythromycin, pirlimycin, tetracycline, and sulfadimethoxine). Descriptive analysis was used to report the frequency of RAPD-types and genotypic clusters within herd, housing system, season and CM severity scores. The minimal antimicrobial concentrations that inhibited 50% (MIC50) and 90% (MIC90) of the isolates were calculated and survival analysis was completed to verify the differences of AMS among genotypic clusters. Results of RAPD showed a great genotypic diversity of Strep. agalactiae (45 RAPD-types) and three clusters (Ia, Ib and II) were created based on the genetic similarity among genotypes. After clustering, a high genetic similarity was observed within and between herds. Overall, Strep. agalactiae showed high susceptibility to most antimicrobials, except to tetracycline and erythromycin. Differences in the AMS among clusters were observed for ampicillin, ceftiofur, erythromycin, pirlimycin, sulfadimethoxine and tetracycline. In conclusion, Strep. agalactiae is still highly susceptible to most antimicrobials, although differences in susceptibility to certain antimicrobials were observed among genotypic clusters.
Topics: Animals; Anti-Bacterial Agents; Cattle; Dairying; Female; Genetic Variation; Genotype; Mastitis, Bovine; Microbial Sensitivity Tests; Milk; Random Amplified Polymorphic DNA Technique; Streptococcal Infections; Streptococcus agalactiae
PubMed: 29928042
DOI: 10.1371/journal.pone.0199561 -
Journal of Microbiology, Immunology,... Aug 2019Streptococcus agalactiae, or group B Streptococcus (GBS), remains to be one of the leading pathogens causing invasive infections in infants.
BACKGROUND
Streptococcus agalactiae, or group B Streptococcus (GBS), remains to be one of the leading pathogens causing invasive infections in infants.
METHODS
The clinical GBS isolates from sterile sites of patients younger than 18 years old were collected from October 1998 to December 2014 in two hospitals in Taiwan. Medical records were retrospectively reviewed. Every isolate was serotyped with a multiplex PCR assay. Multilocus sequence typing (MLST) was performed in representative isolates of different serotypes. A total of 205 GBS isolates were collected from 181 patients with 182 infection episodes.
RESULTS
Serotype Ia was the most common in patients less than 72 h old, whereas III the most common in patients older than 72 h. In early-onset disease (0-6 days), Ia and III each caused 27.5% of the infection, followed by Ib (14.5%). In late-onset disease (7-89 days), serotype III predominated (75.3%), followed by Ia (10.1%) and Ib (6.8%). Thirty-one episodes (17%) were complicated with culture-confirmed meningitis. We compared serotype Ia and III patients, and found that serotype Ia patients were significantly younger (median age, 3 days), had more perinatal maternal fever and higher mortality. ST17 and ST19 were exclusively found in serotype III, while ST23 and ST24 comprised of 85% of serotype Ia.
CONCLUSION
In Taiwan, serotypes Ia and III are the most common cause for early-onset and late-onset neonatal GBS infections, respectively. Some differences in the clinical features of invasive GBS infections caused by serotype Ia and III were observed.
Topics: Adolescent; Anti-Bacterial Agents; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Microbial Sensitivity Tests; Multilocus Sequence Typing; Multiplex Polymerase Chain Reaction; Retrospective Studies; Serogroup; Serotyping; Streptococcal Infections; Streptococcus agalactiae; Taiwan
PubMed: 29100794
DOI: 10.1016/j.jmii.2017.09.002 -
Annals of Clinical Microbiology and... Jan 2019Maternal Streptococcus agalactiae (Group B Streptococcus, GBS) colonization rates and its antibiotic resistance patterns provide important information useful in guiding...
BACKGROUND
Maternal Streptococcus agalactiae (Group B Streptococcus, GBS) colonization rates and its antibiotic resistance patterns provide important information useful in guiding prevention strategies. There is a paucity of evidence about GBS in the Amhara National Regional State, Ethiopia.
OBJECTIVE
To determine colonization prevalence, associated risk factors, and antibiotics resistance including inducible clindamycin resistance patterns of GBS among Ethiopian pregnant women.
METHODS
A prospective cross-sectional study was conducted from 1st December 2016 to 30th November 2017 at the University of Gondar Referral hospital delivery ward. Combined recto-vaginal swabs were collected from 385 pregnant women and analyzed at the University of Gondar Bacteriology Laboratory by using LIM broth and 5% defibrinated sheep blood agar culture methods. Isolates were identified by using colony morphology, gram reaction, hemolysis, and CAMP test. Antibiotic susceptibility test was done using the disc diffusion method. Double disc diffusion method was used to identify inducible clindamycin resistance isolates. Data were analyzed by SPSS version 20 software. p ≤ 0.05 was considered as statistically significant.
RESULTS
The overall prevalence of maternal GBS colonization was 25.5% (95% CI 21-29.5%). Experiencing meconium stained amniotic fluid (AOR = 3.018, 95% CI 1.225, 7.437), and longer duration of premature rupture of membrane (AOR = 1.897, 95% CI 1.014, 3.417) were statistically significant to maternal colonization. Furthermore, GBS resistant to 0 (8.2%), 1 (25.5%) and 3 (39.8%) or more antibiotics were identified. A D-test showed 15.2% inducible clindamycin resistant GBS. Constitutive macrolide lincosamide-streptogramin, L-, and M-phenotypes were also detected.
CONCLUSIONS
Maternal GBS colonization rate in this study was higher compared to the previous reports in Ethiopia. This much prevalence and antibiotics resistance results are the clue to which attention shall be given to this bacterium during management of pregnant women and the newborns.
Topics: Adult; Anti-Bacterial Agents; Clindamycin; Cross-Sectional Studies; Drug Resistance, Bacterial; Ethiopia; Female; Humans; Microbial Sensitivity Tests; Pregnancy; Pregnancy Complications, Infectious; Prevalence; Prospective Studies; Rectum; Risk Factors; Streptococcal Infections; Streptococcus agalactiae; Vagina; Young Adult
PubMed: 30660188
DOI: 10.1186/s12941-019-0303-3 -
Microbiology Spectrum Aug 2022The clustered regularly interspaced palindromic repeat (CRISPR)-associated (Cas) system functions classically as a prokaryotic defense system against invading mobile...
The clustered regularly interspaced palindromic repeat (CRISPR)-associated (Cas) system functions classically as a prokaryotic defense system against invading mobile genetic elements, such as phages, plasmids, and viruses. Our previous study revealed that CRISPR deletion caused increased transcription of capsular polysaccharide (CPS) synthesis-related genes and severely attenuated virulence in the hypervirulent piscine Streptococcus agalactiae strain GD201008-001. Here, we found that CRISPR deficiency resulted in reduced adhesion, invasion, and biofilm formation abilities in this strain by upregulating the production of CPS. However, enhanced CPS production was not responsible for the attenuated phenotype of the ΔCRISPR mutant. RNA degradation assays indicated that inhibited transcription of the operon by CRISPR RNA (crRNA) was not due to the base pairing of the crRNA with the mRNA but to the repression of the promoter activity of , which is a putative transcriptional regulator of the capsule locus. Beyond protection from invading nucleic acids, CRISPR-Cas systems have been shown to have an important role in regulating bacterial endogenous genes. In this study, we demonstrate that crRNA inhibits the transcription of the operon by repressing the activity of promoter P, leading to increases in the abilities of adhesion, invasion, and biofilm formation in S. agalactiae. This study highlights the regulatory role of crRNA in bacterial physiology and provides a new explanation for the mechanism of crRNA-mediated endogenous gene regulation in S. agalactiae.
Topics: Biofilms; CRISPR-Cas Systems; Operon; Polysaccharides; Streptococcus agalactiae; Virulence
PubMed: 35861526
DOI: 10.1128/spectrum.02113-21 -
Epidemiology and Infection Nov 2016We investigated the antibiotic and heavy-metal resistance mechanisms, virulence genes and clonal relationships of macrolide- and/or lincosamide-resistant (M+/-LR)...
We investigated the antibiotic and heavy-metal resistance mechanisms, virulence genes and clonal relationships of macrolide- and/or lincosamide-resistant (M+/-LR) Streptococcus agalactiae (group B Streptococcus, 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+/-LR strains 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+/-LR strains; notably, 5·3% harboured the lsa(C) gene associated with cross-resistance, and tet(W) was identified in a single strain. We report, for the first time, the detection of cadmium and copper resistance encoded by tcrB + cadA + cadC genes in 20 M+/-LR strains, which raises the possibility of co-selection of antibiotic and heavy-metal resistance disseminated through mobile genetic elements. The M+/-LR strains 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.
Topics: Adolescent; Adult; Anti-Bacterial Agents; Drug Resistance, Bacterial; Female; Humans; Lincosamides; Macrolides; Metals, Heavy; Middle Aged; Pregnancy; Spain; Streptococcal Infections; Streptococcus agalactiae; Virulence; Virulence Factors; Young Adult
PubMed: 27499053
DOI: 10.1017/S0950268816001692 -
Biomedica : Revista Del Instituto... Dec 2019Introduction: Streptococcus agalactiae is the main etiological agent causing invasive infection of the newborn with symptoms that may be associated with septicemia,... (Observational Study)
Observational Study
Introduction: Streptococcus agalactiae is the main etiological agent causing invasive infection of the newborn with symptoms that may be associated with septicemia, pneumonia or meningitis and prevalences up to 50% worldwide where there is an increase in antibiotic resistance. Objective: To estimate the prevalence of vagino-rectal colonization by S. agalactiae and its sensitivity profile in pregnant women attending a third-level hospital. Materials and methods: One hundred and twenty one pregnant women were sampled by vaginal and rectal swabs. The cultures were carried out following the methodology recommended by the CDC, and chromID Strepto B agar was added. The suggestive colonies were identified biochemically and the sensitivity profiles according to CLSI were determined. As control, S. pneumoniae ATCC 49619 and S. agalactiae ATCC 12403 were used. Results: Pregnant colonization prevalence by S. agalactiae was 20.66%, with a total of 40 isolates of which 12.5% were non-sensitivity to penicillin. Sensitivity to levofloxacin, clindamycin and erythromycin was 100%, 92.5% y 87.5%, respectively, with the phenotypes iMLSB (3/40) and M (2/40). No sensitivity to tetracycline was found. Conclusions: The prevalence of vagino-rectal colonization by S. agalactiae in the study population was 20.66%, obtaining isolates not sensitive to penicillin and resistance to macrolides and lincosamidas by the Kirby-Bauer technique, so the importance of carrying out active active in pregnant women colonized by Streptococcus agalactiae and to perform constant epidemiological surveillance to detect changes in the sensitivity profiles of the isolates.
Topics: Adult; Colombia; Cross-Sectional Studies; Drug Resistance, Bacterial; Female; Humans; Perineum; Pregnancy; Pregnancy Trimester, Third; Rectum; Streptococcus agalactiae; Tertiary Care Centers; Vagina; Young Adult
PubMed: 31860180
DOI: 10.7705/biomedica.4514