Utility of a novel chromogenic medium as a screening method in the detection of carbapenemase producing Enterobacteriaceae

INTRODUCTION: With the emergence of multidrug resistant Gram-negative bugs, there is an urgent need for rapid detection of these resistant organisms. AIM: This study was performed to assess the utility of a novel chromogenic medium in the detection of carbapenemase producing Enterobacteriaceae from various clinical specimens. MATERIALS AND METHODS: A total of 202 isolates of Enterobacteriaceae, which were resistant to meropenem (10 μg) disc by standard disc diffusion method, were analyzed over a period of 6 months. These isolates were subjected to the modified Hodge test (MHT) and inoculated onto the chromogenic medium. Following which the results were analyzed. RESULTS: It was observed that 76.73% of the Enterobacteriaceae gave a positive result on the MHT, 18.31% were negative and 4.95% gave indeterminate result. While 88.11% produced growth on the chromogenic medium, 6.93% yielded no growth and 4.95% gave variable results. Concordance in the results of the two tests was found to be 65.34%. CONCLUSION: Enterobacteriaceae are emerging to be carbapenem resistant and are responsible for the soaring rates of Healthcare Associated Infections (HAIs), especially among critically ill patients. Hence, early detection of the same is important in controlling HAIs.