Application of carbapenem inactivation method in detection of carbapenemase-producing Acinetobacter baumannii / 中国感染与化疗杂志

ABSTRACT

Objective To evaluate the utility of carbapenem inactivation method (CIM) in detecting carbapenemase-producing Acinetobacter baumannii.Methods A total of 121 strains of A. baumannii were identified and subjected to antimicrobial susceptibility testing by VITEK compact. Carbapenem inactivation method (CIM) was applied to detect the carbapenemase in the A. baumannii strains. The OXA-23 type carbapenemase-encoding genes were analyzed by common PCR method.Results Six-eight of the 121 strains showed resistance to imipenem and meropenem. PCR showed that 65 of the 68 strains carried OXA-23 gene. CIM was positive in 66 of the 68 strains. And 52 of the 121A. baumannii strains were susceptible to imipenem and meropenem. PCR showed that OXA-23 gene was negative in 49 of the 52 strains. CIM was negative in the 52 strains of non-carbapenemase-producing A. baumannii. Only one strain was resistant to imipenem but susceptible to meropenem. CIM was negative but QXA-23 was positive for this strain. The sensitivity and the specificity of CIM was 94.2% and 98.1% respectively in detecting carbapenemase-producing A. baumannii.Conclusions The results of CIM were consistent with the results obtained by PCR to detect the encoding gene of OXA-23. CIM is inexpensive, easier to operate and interpret than PCR method. CIM is applicable to detect OXA-23 type carbapenemase rapidly inA. baumannii.