Suscetibilidade antimicrobiana de Streptococcus agalactiae isolados de gestantes em um hospital materno infantil de Porto Alegre, Rio Grande do Sul

Abstract

AIMS: To characterize the antimicrobial susceptibility profile of Streptococcus agalactiae isolated from pregnant women attended at a public hospital.METHODS: The study was carried out in a public maternal and child hospital in Porto Alegre, RS, Brazil, in which the screening for S. agalactiae in pregnant women is part of the obstetrics routine. The study was carried out on anal/vaginal swab tests performed from July 2015 to February 2016. Bacterial isolates were identified by phenotypic tests, and the susceptibility to ampicillin, clindamycin, erythromycin and ofloxacin was determined. The erythromycin resistance genes ermB and mefA were also investigated.RESULTS: A total of 294 samples were included, and of these, 26 (8%) were positive for S. agalactiae. All isolates were susceptible to ampicillin, and resistance to erythromycin (21.4%), clindamycin (14.3%) and ofloxacin (7.1%) were observed. The mefA genotype was observed in 66% of the erythromycin resistant isolates.CONCLUSIONS: Results of this study corroborate the consensus that in pregnant women colonized with S. agalactiae, intrapartum antibiotic prophylaxis with penicillin G or ampicillin is indicated. The relevant proportion of isolates resistant to erythromycin and clindamycin, indicated for intrapartum antibiotic prophylaxis in case of allergy to beta-lactam antibiotics, emphasizes the importance of determining the profile of antimicrobial susceptibility of these isolates, a measure that is not yet part of routine prenatal tests in many institutions.

Antimicrobial Resistance among Beta-Hemolytic Streptococcus in Brazil: An Overview

“…Analysis of clindamycin and erythromycin non-susceptibility rates over the years was performed with data from 15 studies [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], divided according to the period (until and after 2010) and locality of isolates recovery ( Table 3 ). Non-susceptibility refers to resistant and intermediate isolates, according to CLSI definitions and breakpoints.…”

“…MLS phenotypes, as well as erm genes, were prevalent. Two studies [ 21 , 31 ] reported the occurrence of the L phenotype, but no further genetic characterization of such isolates was available since lnuB gene investigation failed [ 21 ]. Capsular type V has predominated among macrolide-resistant isolates, followed by types Ia and III.…”

“…Fluoroquinolone resistance has been a rare event, reported in only three studies since 2011. Resistance rates have varied from 1–7.1% [ 20 , 30 , 31 ]. Further comprehensive characterization of the first resistant isolates demonstrated a non-clonal relationship among isolates.…”