Molecular characterization and antimicrobial susceptibility profiles in Streptococcus agalactiae colonizing strains: association of erythromycin resistance with subtype III-1 genetic clone family.
Clin Microbiol Infect
; 16(9): 1458-63, 2010 Sep.
Article
in En
| MEDLINE
| ID: mdl-19886900
ABSTRACT
Knowledge of the epidemiology of Streptococcus agalactiae in Portugal is limited therefore, the present study aimed to investigate the carriage rate of S. agalactiae among Portuguese women of reproductive age and the prevalence of antibiotic resistance, as well as to perform a molecular characterization of the clinical isolates. S. agalactiae was recovered from 6.2% of 4269 women during the period 20052007, with a predominance of capsular genotypes III (35%), V (33%), Ia (16%) and II (10%) in a sample of 100 isolates. To our knowledge, this is the first report of the S. agalactiae colonization rate in Portugal determined according to CDC guidelines. All isolates were susceptible to penicillin and vancomycin, whereas resistance to clindamycin and erythromycin was detected in 10% and 19% of isolates, respectively. Among the 19 erythromycin-resistant isolates, ten (53%) displayed the constitutive MLS(B) phenotype (conferring high-level resistance to macrolides), eight (42%) had the inducible MLS(B), and the M phenotype accounted for one isolate (5%). erm methylase genes were exclusively associated with MLS(B) phenotype isolates, whereas the M phenotype was a result of the presence of mefA. Multilocus sequence typing analysis of the genetic relatedness among isolates presenting resistance to erythromycin demonstrated a novel association between erythromycin resistance and the subtype III-1/ST-19 genetic clone family.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Streptococcal Infections
/
Streptococcus agalactiae
/
Carrier State
/
Erythromycin
/
Drug Resistance, Bacterial
Type of study:
Guideline
/
Risk_factors_studies
Limits:
Adolescent
/
Adult
/
Female
/
Humans
/
Middle aged
Country/Region as subject:
Europa
Language:
En
Journal:
Clin Microbiol Infect
Journal subject:
DOENCAS TRANSMISSIVEIS
/
MICROBIOLOGIA
Year:
2010
Document type:
Article
Affiliation country:
Portugal