Determinação da resistência de Staphylococcus aureus: Um desafio?

• Autor(a) principal: Colli, V. C. [UNESP]
• Data de Publicação: 2009
• Outros Autores: Pizzolitto, Antonio Carlos [UNESP], Raddi, Maria Stella Gonçalves [UNESP]
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://serv-bib.fcfar.unesp.br/seer/index.php/Cien_Farm/article/view/882; http://hdl.handle.net/11449/70907
• topic: Clindamycin; MRSA; Phenotypic identification; Staphylococcus aureus; amoxicillin plus clavulanic acid; cefoxitin; clindamycin; erythromycin; oxacillin; penicillin G; adult; antibiotic resistance; antibiotic therapy; bacterial gene; bacterial strain; bacterium isolation; clinical article; disk diffusion; hospitalization; human; laboratory test; methicillin resistant Staphylococcus aureus; nonhuman; normal human; nose smear; phenotype; polymerase chain reaction; pulsed field gel electrophoresis; tongue

The aim of this study was to identify the resistance profile of Staphylococcus aureus strains, in relation to induced clindamycin resistance, and to detect oxacillin resistance by the routine phenotypic methods. The strains were isolated from nasal or lingual swabs taken from healthy adult carriers with no medical history of hospitalization or antibiotic treatment. Eighteen strains were distinguished by the different patterns generated by pulsed field gel electrophoresis (PFGE). Four (22.2%) of these showed sensitivity to clindamycin by the conventional antibacterial susceptibility test, but demonstrated inducible resistance to it by the D-test. One strain (5.6%) was characterized as borderline oxacillin-resistant S. aureus (BORSA), and another (5.6%) as CA MRSA (community-associated methicillin-resistant Staphylococcus aureus). Both of these strains were shown to be cefoxitin susceptible by the disk diffusion test. The polymerase chain reaction (PCR) failed to detect the mecA gene in this last strain and it was thus classified as BORSA. These results show the importance of incorporating the D-test into the routine lab tests for S. aureus inducible clindamycin resistance and also of including the cefoxitin resistance test among the phenotypic methods for MRSA characterization.