Genotypic validation of extended-spectrum β-lactamase and virulence factors in multidrug resistance in an Indian hospital.

The emergence of extended-spectrum β-lactamase (ESBL)-producing has been increasing rapidly across the world. The presence of virulence factors in ESBL producers further adds to the pathogenicity and severity of infection, which often complicate empirical therapy and sometimes result in treatment failures. In the present study, 227 non-repeated clinical isolates of obtained from different clinical specimens from a tertiary care hospital in India were analyzed to detect the genes responsible for ESBL production (blaTEM, blaCTX-M, and blaSHV), virulence (fimH-1, mrkD, entB, irp-1), and capsule production (K1-K2). Phenotypically identified 72 ESBL producing isolates were further subjected to PCR based genotypic analysis but only 20 were found to have at least one of the ESBL producing genes. blaTEM was the most predominant gene (100%), followed by blaSHV (90%), and blaCTX-M (85%). Similarly, the most common virulence genes were fimH-1 (70%), entB (65%), markD (55%), irp-1 (25%), K1 (25%), and K2 (20%). REP-PCR profile separated them into five major clusters (I-V), indicating the existing heterogeneity among the isolates. The resistance profile data obtained from the present study can serve as the information base to understand the infection pattern prevailing in the hospital and for physicians to recommend suitable antibiotics for the patients.