Assuntos
Pneumonia Bacteriana , Humanos , Pneumonia Bacteriana/diagnóstico , Pneumonia Bacteriana/microbiologia , Infecções por Klebsiella/diagnóstico , Infecções por Klebsiella/microbiologia , Enterobacter aerogenes/isolamento & purificação , Enterobacter aerogenes/genética , Masculino , Idoso , Técnicas de Diagnóstico Molecular/métodos , Feminino , Pessoa de Meia-IdadeRESUMO
An increase of carbapenemase-producing Bacteroides fragilis infections is observed. To detect such a resistance in B. fragilis, several tests exist that are expensive or show poor sensitivity and specificity. Therefore, we upgraded the Anaerobic Carbapenem Inactivation Method (Ana-CIM) to easily screen for carbapenemase-producing B. fragilis. The presence of carbapenemase cfiA gene was identified in 50 B. fragilis isolates by PCR. We modified the Ana-CIM by (1) increasing the bacterial inoculum, and (2) measuring the differences in diameter between the negative control and the testing disc. We correctly classified the cfiA-negative and positive isolates and could define a cut-off of positivity at 2 mm. Our modified Ana-CIM allowed to correctly discriminate the 31 cfiA-positive with meropenem MICs ranging from 1 to > 32 µg/mL. We anticipate that our modified Ana-CIM could be used in most clinical laboratories to easily screen for carbapenemase-producing B. fragilis, even at low levels.
