Serotypes and antimicrobial susceptibility of group B streptococcus isolated from neonates in Casablanca

The serotypes and the levels of antibiotic resistance of 59 Streptococcus agalactiae isolates from neonates in Casablanca, from February 1992 to July 1997, were studied. Most of the isolates (86.4%) were recovered from early-onset disease. The serotype distribution was as follows: serotype III 39%; serotype Ia 32.2%; and serotype V 10.2%. All strains were susceptible to penicillin G, cefotaxime and ampicillin, whereas 1 strain was resistant to erythromycin. No high level of resistance to gentamicin was detected. A vaccine should comprise the most prevalent serotypes and also provide protection against serotype V disease. The antibiotic susceptibility patterns reported here support the recommended treatment and prophylaxis of invasive group B Streptococcal disease.