Epidemiological study of staphylococcal colonization and cross-infection in two west African hospitals

Surveillance in two medium-size (250-300 beds) hospitals located in the mos t populated islands of Cape Verde was undertaken in July 1997 in order to o btain data concerning nasal carriage of staphylococci, Nasal swabs (172) ta ken from inpatients and health care workers (HCW) from different internment services yielded 68 Staphylococcus aureus and 105 coagulase-negative staph ylococcal (CNS) isolates, demonstrating extensive colonization of both inpa tients and HCW by S, aureus (carriage rate 41%) and CNS (carriage rate 65%) , The most frequent CNS species were S, epidermidis and S, haemolyticus, Th ree species-S. aureus, S, epidermidis, and S, sciuri-were recovered from wo und swabs. The antibiotic susceptibility profiles of S, aureus and CNS diff ered sharply: all 68 S. aureus were resistant to penicillin but were fully susceptible to oxacillin as well as the other antimicrobial agents tested-g entamicin; erythromycin, except for three strains; ciprofloxacin; sulfameth oxazole-trimethoprim, except for two strains; vancomycin; and amoxicillin/c lavulanate. In contrast, most (91/105) of CNS were resistant to both penici llin and oxacillin, and a variable but substantial proportion of CNS isolat es also carried multiresistant traits to gentamicin, erythromycin, sulfamet hoxazole-trimethoprim, and amoxicillin/clavulanate. The analysis by PFGE of the methicillin-susceptible S, aureus (MSSA) and the methicillin-resistant S, epidermidis (MRSE) strains provided evidence for extensive cross-infect ion and cross-colonization from HCW to patients.