title: Comparison of five methods for oxacillin susceptibility testing of Staphylococcus aureus isolates from cystic fibrosis patients.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) are now a worldwide problem. Cystic fibrosis (CF) patients are commonly colonized and infected by MRSA. Accurate oxacillin susceptibility testing is mandatory for the adequate management of these patients. We performed a comparison of the accuracy of different tests in CF isolates, including methicillin-susceptible S. aureus and MRSA with different SCCmec types, and using the mecA gene as the gold-standard. The sensitivity and specificity of oxacillin disc, Etest, and oxacillin agar screening plate were 100%. Sensitivity of the cefoxitin disc was 85% and specificity was 100%. For clinically relevant isolates, laboratories may consider the use of a combination of two phenotypic methods.
authors.affiliation: Division of Microbiology, Department of Pathology, Santa Casa School of Medicine, São Paulo, SP, Brazil. mjmimica@hotmail.com
authors.forename: Marcelo J
authors.initials: MJ
authors.lastname: Mimica
authors.forename: Rozane L
authors.initials: RL
authors.lastname: Carvalho
authors.forename: Eitan N
authors.initials: EN
authors.lastname: Berezin
authors.forename: Neiva
authors.initials: N
authors.lastname: Damaceno
authors.forename: Hélio H
authors.initials: HH
authors.lastname: Caiaffa-Filho
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D003470:Culture Media / Q000737:chemistry; D003550:Cystic Fibrosis / Q000382:microbiology*; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics; D008826:Microbial Sensitivity Tests / Q000379:methods; D010068:Oxacillin / Q000494:pharmacology*; D046915:Penicillin-Binding Proteins; D010641:Phenotype; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003470:Culture Media; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus; D010068:Oxacillin