Genetic similarity between staphylococcus sp isolated from human and hospital settings, and susceptibility to different antimicrobials.

ABSTRACT

One hundred and forty-three samples from human hands and hospital beds were collected at a teaching hospital in the city of Ribeirão Preto/SP by swabs, and placed in BHI broth. Following a 24 h incubation period at 37°C, they were seeded on Petri dishes containing Agar "Staphylococcus Medium 110". Colonies typical of the genus Staphylococcus were collected and stored at 4°C until tested for catalase, mannitol, hemolysis, DNAse and coagulase. Strains were analyzed by RAPD-PCR to verify their similarity, and tested for sensitivity to ten different antibiotics. From the ninety-two isolated strains, 67 (72,8%) were coagulase- negative and 25 (27,2%) coagulase-positive. Similarity analysis showed a great heterogeneity among strains, but some presented 100% similarity. Resistance to oxacilin was encountered in 39 (42%) of the strains. Two coagulase-negative strains were resistant to vancomycin, and eleven (12%) were considered multiresistant. Measures such as hand disinfection of the staff and hospital beds and rationalization of antibiotic use could contribute to decrease pathogen transmission and selection pressure, diminishing the frequency and lethality of nosocomial infections.