Prevalence and mechanisms of erythromycin resistance in Streptococcus agalactiae from healthy pregnant women.

  1. Pinheiro, S. 1
  2. Radhouani, H. 1
  3. Coelho, C. 1
  4. Gonçalves, A. 1
  5. Carvalho, E. 1
  6. Carvalho, J.A. 1
  7. Ruiz-Larrea, F. 2
  8. Torres, C. 2
  9. Igrejas, G. 1
  10. Poeta, P. 1
  1. 1 Universidade de Trás-os-Montes e Alto Douro
    info

    Universidade de Trás-os-Montes e Alto Douro

    Vila Real, Portugal

    ROR https://ror.org/03qc8vh97

  2. 2 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

Revista:
Microbial Drug Resistance

ISSN: 1076-6294

Año de publicación: 2009

Volumen: 15

Número: 2

Páginas: 121-124

Tipo: Artículo

PMID: 19432524 SCOPUS: 2-s2.0-70349771526 WoS: WOS:000266640200009 GOOGLE SCHOLAR

Otras publicaciones en: Microbial Drug Resistance

Resumen

We sought to determine the resistance phenotypes for erythromycin and clindamycin and the mechanisms implicated in 93 Streptococcus agalactiae isolates recovered from healthy pregnant women. Susceptibility testing for erythromycin, clindamycin, penicillin, cefotaxime, vancomycin, quinupristin-dalfopristin, choramphenicol, ofloxacin, and meropenen was carried out by disc-diffusion test, and the E-test was also applied for erythromycin and clindamycin. The constitutive MLS(B) resistance (cMLS(B)) and inducible MLS(B) resistance (iMLS(B)) phenotypes, respectively, as well as the M resistance phenotype were determined by the erythromycin-clindamycin double-disc test. The presence of ermA, ermB, ermC, msrA, and mef(A/E) macrolide resistance genes was studied by PCR. Resistance to erythromycin and clindamycin was found in 15% and 9.6% of the isolates, respectively. The resistance phenotypes detected among the 14 erythromycin-resistant isolates were as follows (number of isolates): cMLS(B) (9), iMLS(B) (3), and M (2). The MICs for erythromycin and clindamycin were as follows: cMLS(B) isolates (128-256 and >or=32 mg/L, respectively), iMLS(B) isolates (16-256 and 1 mg/L), and M isolates (2-8 and 1 mg/L). The following combination of genes were detected among isolates with cMLS(B) or iMLS(B) phenotypes: erm(B) (6 isolates), ermA + ermTR (3), ermA + ermB + ermTR (1), and none of these genes (2). The two isolates with M phenotype harbored the mef(A/E), and msrA gene was also found in one of them.