RESUMO
BACKGROUND: Group 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. METHODS: A 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. RESULTS: Overall, 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. CONCLUSION: These 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.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/isolamento & purificação , Fatores de Virulência/genética , Adulto , Idoso , Brasil/epidemiologia , Clindamicina/farmacologia , Farmacorresistência Bacteriana Múltipla , Eritromicina/farmacologia , Feminino , Variação Genética , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Gravidez , Complicações na Gravidez/epidemiologia , Complicações na Gravidez/microbiologia , Sorotipagem , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae/classificação , Streptococcus agalactiae/fisiologia , Tetraciclina/farmacologia , VirulênciaRESUMO
In this study it was compared the MAS-100 and the Andersen air samplers' performances and a similar trend in both instruments was observed. It was also evaluated the microbial contamination levels in 3060 samples of offices, hospitals, industries, and shopping centers, in the period of 1998 to 2002, in Rio de Janeiro city. Considering each environment, 94.3 to 99.4% of the samples were the allowed limit in Brazil (750 CFU/m3). The industries' results showed more important similarity among fungi and total heterotrophs distributions, with the majority of the results between zero and 100 CFU/m3. The offices' results showed dispersion around 300 CFU/m3. The hospitals' results presented the same trend, with an average of 200 CFU/m3. Shopping centers' environments showed an average of 300 CFU/m3 for fungi, but presented a larger dispersion pattern for the total heterotrophs, with the highest average (1000 CFU/m3). It was also investigated the correlation of the sampling period with the number of airborne microorganisms and with the environmental parameters (temperature and air humidity) through the principal components analysis. All indoor air samples distributions were very similar. The temperature and air humidity had no significant influence on the samples dispersion patterns.
Assuntos
Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental/métodos , Fungos/isolamento & purificação , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Humanos , Análise de Componente PrincipalRESUMO
In this study it was compared the MAS-100 and the Andersen air samplers' performances and a similar trend in both instruments was observed. It was also evaluated the microbial contamination levels in 3060 samples of offices, hospitals, industries, and shopping centers, in the period of 1998 to 2002, in Rio de Janeiro city. Considering each environment, 94.3 to 99.4 percent of the samples were the allowed limit in Brazil (750 CFU/m ). The industries' results showed more important similarity among fungi and total heterotrophs distributions, with the majority of the results between zero and 100 CFU/m . The offices' results showed dispersion around 300 CFU/m . The hospitals' results presented the same trend, with an average of 200 CFU/m . Shopping centers' environments showed an average of 300 CFU/m for fungi, but presented a larger dispersion pattern for the total heterotrophs, with the highest average (1000 CFU/m ). It was also investigated the correlation of the sampling period with the number of airborne microorganisms and with the environmental parameters (temperature and air humidity) through the principal components analysis. All indoor air samples distributions were very similar. The temperature and air humidity had no significant influence on the samples dispersion patterns.