Prevalence of Carbapenemase Production Among Klebsiella and Escherichia coli Isolated From Urinary Tract Infections

Background and aim Urinary tract infections represent a substantial portion of healthcare-associated infections due to <i>E. coli</i> and <i>Klebsiella</i>. Carbapenems are broad-spectrum antibiotics considered highly effective in treating infections caused by multidrug-resistant bacteria. Carbapenem-resistant <i>Enterobacteriaceae (</i>CRE), including carbapenem-producing <i>E. coli</i> and <i>Klebsiella</i> isolates, have become a major concern as they limit treatment options. The study aims to determine the prevalence of carbapenemase-producing <i>E. coli</i> and <i>Klebsiella</i> while also comparing the effectiveness of two detection methods, namely the modified carbapenem inactivation method (mCIM) and modified Hodge test (MHT). Materials and methods A cross-sectional study was conducted from July 2022 to June 2023 in a tertiary care hospital, in Karad, Satara, India. Three hundred urinary isolates of <i>E. coli</i> (150) and <i>Klebsiella</i> (150) were studied. These isolates were tested for antimicrobial susceptibility testing. Two phenotypic methods, the modified carbapenem inactivation method (mCIM) and the modified Hodge test (MHT), were used to study carbapenemase production. Results Out of three hundred isolates, carbapenemase production was detected in 72 isolates (24%) by the modified Hodge test (MHT) and in 111 isolates (37%) by the modified carbapenem inactivation method (mCIM). Among the MHT-positive isolates, 46 (63.8%) were identified as <i>Klebsiella</i> and 26 (36.1%) as <i>E. coli</i>. In contrast, of the mCIM-positive isolates, 68 (61.2%) were <i>Klebsiella</i>, and 43 (38.7%) were <i>E. coli</i>. A total of 41 <i>Klebsiella</i> (27.33%) and 25 <i>E. coli</i> (16.66%) isolates tested positive by both methods, highlighting variability in detection rates between the two methods. Conclusion This study observed MHT and mCIM to be accurate for the detection of carbapenemase among carbapenem-resistant isolates. However, the mCIM demonstrated greater sensitivity compared to the MHT.