Multiplex PCR: A Molecular Modality for Rapid Detection of CTX-M-15, AAD A1 and QNR S1 Genes among Drug Resistant Clinical Isolates of Enterobacteriaceae in Kanchipuram, South India

Abstract

Multidrug resistance is a potential threat to the mankind. The prevalence rate of multidrug resistant bacteria is worrisome and has gained significant attention globally. Hence it becomes imperative for clinical laboratories to identify these multidrug resistant pathogens for appropriate therapy. It is equally important to detect the resistance mechanisms which would aid in understanding and development of new therapeutic options. This study was carried out to identify the prevalence of multidrug resistant Enterobacteriaceae from clinical samples recovered from Kanchipuram district. The study was also implicated in designing of novel primers using primer3 tool and standardizing a multiplex PCR targeting ctxm- 15, aadA1, qnrS1 genes in the isolates. Of the 60 clinical isolates studied, 14, 13 and 12 isolates harbored ctx-m-15, qnrS1 gene and aadA1genes respectively. Among these, 2 isolates carried both ctx-m-15 and qnrS1 genes and 3 isolates were found to carry both ctx-m-15 and aadA1 genes. 1 isolate was found to be positive for both aadA1 and qnrS1 genes. None of these isolates harbored all the three targeted genes qnrS1 and aadA1, ctx-m-15. The present study will aid in detecting drug resistant genes like ctx-m-15, aadA1, qnrS1 in clinical isolates with higher sensitivity and specificity and will also reduce the cost of reaction than that required for uniplex PCR. The prevalence rate of drug resistant genes among Kanchipuram district alerts us for the measures needed to be undertaken to control the spread of drug resistant genes in community.