Phenotypic and genotypic characterization of Streptococcus agalactiae in pregnant women. First study in a province of Argentina.

OVIEDO P, PEGELS E, LACZESKI M, QUIROGA M, VERGARA M

BRAZILIAN JOURNAL OF MICROBIOLOGY

SOC BRASILEIRA MICROBIOLOGIA

Año: 2013 vol. 44 p. 253 - 258

1517-8382

Group BStreptococcus(GBS) is the leading cause of neonatal infections. Our purpose was to characterize GBS colonization in pregnant women, current serotypes, resistance phenotypes and genesassociated with virulence. In Misiones, Argentina, there are no previous data on this topic. Vaginalrectal swabs from 3125 pregnant women were studied between 2004 and 2010. GBS strains wereidentified by conventional and serological methods (Phadebact Strep B Test, ETC International,Bactus AB, Sweden). Serotypes were detected using Strep-B Latex (Statens Serum Institut, Denmark). Resistance phenotypes were determined by the double-disk test. Genes were studied by PCR.Maternal colonization was 9.38%. Resistance to erythromycin was 11.6%, and the constitutive phenotype was the predominant one. Serotype Ia was the most frequent, whereas serotypes IV, VI, VII and VIII were not detected. Thelmb, bcaand hylBgenes were detected in more than 79% of the strains. In this study, the colonization rate with GBS and the serotype distribution were comparedwith studies reported in other areas of the country. The high resistance to erythromycin in Misiones justifies performing antibiotic susceptibility testing. The serotype distribution, the genes encoding putative virulence factors, and the patterns of resistance phenotypes of GBS may vary in different areas. They thus need to be evaluated in each place to devise strategies for prevention.