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OMIG Main Page | 2005 Abstracts | < Previous | Next > Identification of Methicillin Resistant Coagulase Negative Staphylococcus in Ophthalmic Infections AL Hofling-Lima, AAA Oliveira, D Freitas, C Viana, J Sampaio, W Francisco, C Lottenberg, MDV Martino Universidade Federal de Sao Paulo - Department de Oftalmologia - UNIFESP/EPM Purpose- To evaluate different oxacillin susceptibilitity methods from ocular recovered isolates, considering multiplex PCR assay for detection of the Staphylococcal mecA gene as the gold standard. Methods: The Vitek gram positive identification card was used to identify ocular coagulase negative Staphylococcus (CNS) species. They were classified into 2 groups according to absence or presence of mecA gene determinated by PCR. The multiplex assay combined 2 primer sets (mecA and 16S rRNA) in a single region These groups were analyzed, comparing the results of PCR with others oxacillin susceptibility methods: disk diffusion for oxacillin 1 ug and cefoxitin 30 ug; oxacillin E-test PBP2a detection by rapid slide latex agglutination test, the Vitek automated Gram positive Susceptibility card (GPS-105) and agar screening test (AST) at a concentration of 6, 1 and 0.75 ug oxacillin per ml, Results- Of 69 CNS tested. 20 were mecA positive and 49 negative. The group with negative mecA detection had an agreement in 100%; 85%; 80%, 100%-100% 95%- 100% and 100% with the latex; E-test; the OPS-1 U3; oxacil'lin AST at a concentration of 6, 1and 0.75 ug/ml; oxacillin and cefoxitin disk diffusion test respectively. The group with positive mecA gene detection had an agreement in 93.9%; 100%; 95.9%; 89.8%; 98%; 100%; 55.1% and 89 8% with the latex; E-test; the GPS-105; AST at a concentration of 6, and 0.75 ug oxacillin per ml; oxacillin and cefoxitin disk diffusion test respectively. Conclusions: In the present study, we observed that E-test and AST with 0.75 ug oxacillin per ml, comparing with the PCR, were the most accurate available phenotypic methods at detecting Staphylococci oxacillin resistance. A good option for screening of the oxacillin resistance is cefoxitin disk diffusion test and Vitek system OMIG Main Page | 2005 Abstracts | < Previous | Next >
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