Antimicrobial susceptibility patterns amongst group B streptococci from women in Harare, Zimbabwe

As part of a larger study of vaginal pathogens in women in Harare, we have examined the antimicrobial susceptibility patterns of 130 isolates of group B streptococci (GBS). These organisms are important because of their association with preterm labour, premature rupture of membranes and neonatal sepsis. All of the isolates in Harare were fully sensitive to beta-lactams, with an MIC(90) for ampicillin of 0.38 mg/l, but five isolates were resistant in vitro to erythromycin, and each of these had an MIC >4 mg/l. Seven isolates showed resistance to clindamycin. Some isolates showed an intermediate sensitivity to gentamicin, but the great majority were resistant to this antibiotic. Studies in developed countries have shown that an intervention strategy, using intrapartum chemoprophylaxis, is effective in reducing the incidence of complications of GBS colonization in pregnant women. Our data suggest that ampicillin would be a suitable antibiotic for use in an intervention programme of intrapartum chemoprophylaxis in Harare.