Evaluation Of Phenotypic Methods For Detection Of Carbapenem Resistance In Isolates Of Pseudomonas Aeruginosa In A Tertiary Care Hospital

Abstract

Objective: To assess the effectiveness of Modified Hodge test (MHT) and Modified carbapenemase inactivation method (mCIM) for detection of carbapenemase enzyme produced by Pseudomonas aeruginosa strains that code for resistance towards carbapenem. Study Design and Setting: This observational cross sectional study was carried out from January 18 to January 19 in microbiology department of PNS SHIFA Karachi. Methodology: 140 isolates of Pseudomonas aeruginosa were cultured from pus samples of hospitalized patients from different wards like ENT, Surgery, Burn Unit, Plastic Surgery, ICU, Medicine, Pediatrics and family ward. These isolates were tested carbapenem resistance by two phenotypic methods namely MHT and mCIM test. This data was analyzed by using SPSS Version 23.0. Results: In our research study mCIM method showed 100% sensitivity, 99.1% specificity, positive predictive value 96.1% and negative predictive value 100% as compare to Modified Hodge Test which gave 77% sensitivity, 99.1% specificity, 95.2% PPV and 100% NPV. Conclusion: mCIM test is simple, accurate and more reliable method for detection of carbapenemase production as compared with MHT. It is recommended, cabapenemase producing isolates should be tested as a routine practice by all clinical labs laboratory.