title: Evaluation of phenotypic methods for methicillin resistance characterization in coagulase-negative staphylococci (CNS).
abstract: Coagulase-negative staphylococci (CNS) are the major cause of nosocomial infections. Methicillin-resistant strains are particularly important because they narrow therapeutic options. Detecting methicillin resistance among CNS has been a challenge for years. The objective of this study was to determine the accuracy of an agar screening test (0.6 and 4 microg oxacillin ml(-1)), disc diffusion and the automated MicroScan system to characterize methicillin resistance among CNS. One hundred and seventy five strains were analysed: 41.1 % Staphylococcus epidermidis and 59.9 % other species; 69.1 % were mecA-positive. The results showed that the methods have optimal correlation with the detection of mecA gene for S. epidermidis, Staphylococcus hominis and Staphylococcus haemolyticus. However, accuracy of the tests is impaired when less common species are analysed. The only 100 % accurate test was agar screening with 4 microg oxacillin ml(-1).
authors.affiliation: Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Rua Sarmento Leite 245/211, Porto Alegre, RS 90050-170, Brazil 2Hospital Mãe de Deus, Porto Alegre, Brazil 3Laboratório Central de Análises Clínicas da Irmandade Santa Casa de Misericórdia de Porto Alegre, RS, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Caierão
authors.affiliation: Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Rua Sarmento Leite 245/211, Porto Alegre, RS 90050-170, Brazil 2Hospital Mãe de Deus, Porto Alegre, Brazil 3Laboratório Central de Análises Clínicas da Irmandade Santa Casa de Misericórdia de Porto Alegre, RS, Brazil.
authors.forename: Maiara
authors.initials: M
authors.lastname: Musskopf
authors.affiliation: Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Rua Sarmento Leite 245/211, Porto Alegre, RS 90050-170, Brazil 2Hospital Mãe de Deus, Porto Alegre, Brazil 3Laboratório Central de Análises Clínicas da Irmandade Santa Casa de Misericórdia de Porto Alegre, RS, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Superti
authors.affiliation: Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Rua Sarmento Leite 245/211, Porto Alegre, RS 90050-170, Brazil 2Hospital Mãe de Deus, Porto Alegre, Brazil 3Laboratório Central de Análises Clínicas da Irmandade Santa Casa de Misericórdia de Porto Alegre, RS, Brazil.
authors.forename: Eliane
authors.initials: E
authors.lastname: Roesch
authors.affiliation: Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Rua Sarmento Leite 245/211, Porto Alegre, RS 90050-170, Brazil 2Hospital Mãe de Deus, Porto Alegre, Brazil 3Laboratório Central de Análises Clínicas da Irmandade Santa Casa de Misericórdia de Porto Alegre, RS, Brazil.
authors.forename: Cícero G
authors.initials: CG
authors.lastname: Dias
authors.affiliation: Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Rua Sarmento Leite 245/211, Porto Alegre, RS 90050-170, Brazil 2Hospital Mãe de Deus, Porto Alegre, Brazil 3Laboratório Central de Análises Clínicas da Irmandade Santa Casa de Misericórdia de Porto Alegre, RS, Brazil.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: d'Azevedo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010068:Oxacillin / Q000494:pharmacology; D010641:Phenotype; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013210:Staphylococcus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008712:Methicillin; D010068:Oxacillin