Evaluation of carbapenem inactivation method for accuratedetection of pseudomonas aeroginosa isolates producing carbapenemaseenzymes

Background and Aim : Different phenotypic methods are available for identification ofpseudomonas aeroginosa isolates producing carbapenemase enzymes. Carbapenem inactivationmethod (CIM) is a fast and inexpensive way for detection of this enzyme. The purpose of thisstudy was to evaluate the CIM method for accurate identification of carbapenemase producingpseudomonas aeruginosa isolates.Methods : A total of ۹۷ clinical specimens were collected from the patients in the hospitals ofHamadan from November ۲۰۱۷ to May ۲۰۱۸, in Iran. Antibiotic susceptibility test was performedby disc diffusion method. Minimum inhibitory concentration (MIC) for imipenem was measuredby E-test. Then, CIM test and polymerase chain reaction (PCR) methods were performed.Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of theCIM test were calculated for each of the genes. Using SPSS۱۶ software, significance of CIM testwas evaluated by chi-square test (X۲).Results : In this study, the highest and lowest levels of resistance belonged to cefoxitin ۹۱ (۹۳.۸%)and piperacilin/tazobactam ۳۸ )۳۹.۲%). Among ۹۷ P. aeruginosa clinical isolates, ۴۹ (۵۰.۵۱%)were carbapenemase producer with positive results for CIM test in ۴۴ (۸۹.۷%) isolates, andnegative results for CIM test in ۴۸ (۴۹.۴۸%) isolates. Therefore, the sensitivity and specificity ofthe CIM test were ۹۰% and ۱۰۰%, respectively.Conclusion : According to the results of this study CIM method is an inexpensive test which canbe easily performed and has high sensitivity and specificity for identification of carbapenemaseproducing P. aeruginosa isolates.

کلیدواژه ها:

Pseudomonas aeruginosa ، PCR ، CIM