The genetic diversity and phenotypic characterisation of Streptococcus agalactiae isolates from Rio de Janeiro, Brazil

Corrêa, Ana Beatriz de Almeida; Silva, Ligia Guedes da; Pinto, Tatiana Castro Abreu; Oliveira, Ivi Cristina Menezes de; Fernandes, Flávio Gimenis; Costa, Natália Silva; Mattos, Marcos Corrêa de; Fracalanzza, Sérgio Eduardo Longo; Benchetrit, Leslie C.

doi:10.1590/s0074-02762011000800017

Cited by 19 publications

(31 citation statements)

References 29 publications

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“…Erythromycin resistance has been documented worldwide in studies concerning S. agalactiae strains of human and bovine origin. In the United States and Europe, resistance rates of approximately 4-50% have been reported (DIPERSIO; DIPERSIO, 2006;DOGAN et al, 2005;GUÉRIN-FAUBLÉE et al, 2002;SADOWY et al, 2010), while in Brazil, estimates have been lower than 10% (CORRÊA et al, 2011;DUARTE et al, 2004DUARTE et al, , 2005PALMEIRO et al, 2010). However, of the Brazilian bovine isolates examined by Pinto et al (2013), 27.6% were resistant to this antibiotic, a higher value than that recorded in the present work (19.5%).…”

Section: Resultsmentioning

confidence: 99%

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

Silva

Castro

Gonçalves

et al. 2017

SCA

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Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%), tetO in 23 (19.5%), and tetM in 24 (20.3%). The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%), tetracycline (35.6%), gentamicin (9.3%), clindamycin (20.3%), penicillin (3.4%), and amikacin (38.1%); conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health. Key words: Antimicrobial resistance genes. Bovine diseases. Bovine mastitis. GBS, MIC. ResumoStreptococcus agalactiae é um dos principais agentes causadores de mastite em bovinos e de consequentes perdas econômicas aos produtores. Poucos estudos que avaliaram a susceptibilidade a antimicrobianos e a presença de determinantes genéticos de resistência para este agente em bovinos leiteiros do Brasil. Este trabalho teve por objetivo avaliar a frequência dos genes de resistência a antimicrobianos ermA, ermB, mefA, tetO, tetM, aphA3, aad-6, bem como a susceptibilidade in vitro aos antimicrobianos amicacina, eritromicina, clindamicina, tetraciclina, gentamicina, penicilina, ceftiofur e cefalotina, e as associações entre genótipos e fenótipos de resistência em 118 isolados de S. agalactiae provenientes de casos de mastite em rebanhos bovinos brasileiros. Dentre os genes de resistência pesquisados, ermB foi encontrado em 19 isolados (16,1%), tetO em 23 (19,5%) e tetM em 24 (20,3%). Os genes ermA, mefA, apha3 e aad6 não foram detectados. Verificou-se associação entre a presença dos genes ermB, tetM e tetO e os fenótipos de resistência à eritromicina, clindamicina e tetraciclina. Foram encontrados diferentes índices de resistência aos antibióticos testados: Eritromicina (19,5%), tetraciclina (35,6%), gentamicina (9,3%), clindamicina (20,3%), penicilina (3,4%) e amicacina (38,1%). Todos os isolados foram susceptíveis ceftiofur e cefalotina. ...

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Section: Resultsmentioning

confidence: 99%

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

Silva

Castro

Gonçalves

et al. 2017

SCA

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“…Likewise, serotype does not seem to have a correlation with the classification of a GBS isolate in a clonal group. Relationships between the serotype and the source of isolation or between the serotypes and PFGE profiles were also not detected in another Brazilian study [14]. This fact could be explained by the occurrence of capsule switching between GBS isolates by horizontal gene transfer, as a result of pressures by immune response of the host [7].…”

Section: Discussionmentioning

confidence: 96%

“…Other studies have described the predominance of serotypes III and V among cases of infection in neonates and in non-pregnant adults, respectively [25,34] while serotype Ia was found to predominate among GBS causing invasive infections in non-pregnant adults in Portugal [36]. In Brazil, previous studies showed that serotypes Ia, II, III and V were found in 68.2% of isolates predominantly from vaginal specimens of asymptomatic pregnant woman [14]. On the other hand, serotype IV was detected in 13.1% of the isolates from Curitiba city, Paraná state, Brazil, being most of them from infectious cases [13], and serotypes Ib (34.9%) and Ia (25.6%) were predominant among a cohort of HIV-infected pregnant women in Rio de Janeiro city [35].…”

Section: Discussionmentioning

confidence: 99%

Streptococcus agalactiae in Brazil: serotype distribution, virulence determinants and antimicrobial susceptibility

Dutra

Alves

Olendzki³

et al. 2014

BMC Infect Dis

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BackgroundGroup B Streptococcus (GBS) remains a major cause of neonatal sepsis and is also associated with invasive and noninvasive infections in pregnant women and non-pregnant adults, elderly and patients with underlying medical conditions. Ten capsular serotypes have been recognized, and determination of their distribution within a specific population or geographical region is important as they are major targets for the development of vaccine strategies. We have evaluated the characteristics of GBS isolates recovered from individuals with infections or colonization by this microorganism, living in different geographic regions of Brazil.MethodsA total of 434 isolates were identified and serotyped by conventional phenotypic tests. The determination of antimicrobial susceptibility was performed by the disk diffusion method. Genes associated with resistance to erythromycin (ermA, ermB, mefA) and tetracycline (tetK, tetL, tetM, tetO) as well as virulence-associated genes (bac, bca, lmb, scpB) were investigated using PCR. Pulsed-field gel electrophoresis (PFGE) was used to examine the genetic diversity of macrolide-resistant and of a number of selected macrolide-susceptible isolates.ResultsOverall, serotypes Ia (27.6%), II (19.1%), Ib (18.7%) and V (13.6%) were the most predominant, followed by serotypes IV (8.1%) and III (6.7%). All the isolates were susceptible to the beta-lactam antimicrobials tested and 97% were resistant to tetracycline. Resistance to erythromycin and clindamycin were found in 4.1% and 3% of the isolates, respectively. Among the resistance genes investigated, tetM (99.3%) and tetO (1.8%) were detected among tetracycline-resistant isolates and ermA (39%) and ermB (27.6%) were found among macrolide-resistant isolates. The lmb and scpB virulence genes were detected in all isolates, while bac and bca were detected in 57 (13.1%) and 237 (54.6%) isolates, respectively. Molecular typing by PFGE showed that resistance to erythromycin was associated with a variety of clones.ConclusionThese findings indicate that GBS isolates circulating in Brazil have a variety of phenotypic and genotypic characteristics, and suggest that macrolide-resistant isolates may arise by both clonal spread and independent acquisition of resistance genes.

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“…In addition, there is a close relationship between serologic type and virulence in these microorganisms. 9,15,[20][21][22] In our study, multiplex PCR identified the serotypes Ia, V, II, Ib, III, VI. Serotype VI is rarely described: it had never been reported in Brazil or in other Latin American countries until this day.…”

Section: ■ Discussionmentioning

confidence: 87%

Molecular Characterization of Group B Streptococcus Serotypes By Multiplex Polymerase Chain Reaction

Andrade¹,

Russo²,

Gouveia³

et al. 2017

Medical Express

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OBJECTIVE: Group B Streptococcus (GBS) serotypes (Ia, Ib and II to IX) are classified based on variations in their capsular polysaccharide; their prevalence differs between different geographic areas. We examined the prevalence of all GBS serotypes in rectal and vaginal swab samples obtained from 363 pregnant women followed at a Brazilian referral center (Hospital da Mulher Professor Doutor José Aristodemo Pinotti); bacterial susceptibility to antibiotics was further determined. METHOD: Prevalence of positive GBS was evaluated by latex agglutination and by multiplex PCR analysis; bacterial susceptibility to antibiotics, such as clindamycin, erythromycin, levofloxacin, linezolid, penicillin and tetracycline was determined by the disk diffusion method. RESULTS: (a) standard GBS culture and the multiplex PCR analysis tested positive for 83 swabs, collected from 72 women (prevalence of GBS colonization: 72/363; 20%); the most prevalent Serotype was Ia (n=43/83; 52%), followed by serotype V (n=14/83; 17%); according to anatomical origin, serotype Ia accounted for 27/59 (46%) and 16/24 (67%) of the vaginal and rectal samples, respectively; PCR also identified serotypes Ib, II, III and VI. Serotype VI is rarely described and had not been previously reported in Brazil or in Latin America. (b) The latex agglutination test only identified 44 positive samples, all of which were serotyped: 34 of these samples (77%) had serotypes matching those identified by multiplex PCR. (c) Only one sample (serotype Ia) showed resistance to erythromycin and clindamycin. CONCLUSION: Regional studies on GBS serotypes prevalence are essential to guide immunoprophylactic interventions (vaccines) and the implementation of adequate antibiotic prophylaxis or treatment. In this study, the incidence of the serotype VI, a new and rare serotype of GBS was described for the first time in a Brazilian population.

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The genetic diversity and phenotypic characterisation of Streptococcus agalactiae isolates from Rio de Janeiro, Brazil

Cited by 19 publications

References 29 publications

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

Streptococcus agalactiae in Brazil: serotype distribution, virulence determinants and antimicrobial susceptibility

Molecular Characterization of Group B Streptococcus Serotypes By Multiplex Polymerase Chain Reaction

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