Abstract
Soil is the richest natural source of antibiotic producing bacteria as well as for the development of resistance against the produced antibiotics or their residues. The present study was performed to assess the presence of beta lactamase among environmental isolates obtained from soil from regions with history of selective pressure due to human activity as well as from regions with no anthropogenic activity. A total of 64 isolates of family Enterobacteriaceae were obtained from the soil samples from different sites of Shillong, Meghalaya. Antimicrobial susceptibility was performed by Kirby-Bauer disc diffusion method. All the isolates were subjected to phenotypic detection of AmpC beta-lactamases and extended spectrum beta lactamases (ESBLs). Multiplex PCR targeting ESBL genes (blaTEM, blaCTX-M, blaSHV, blaOXA-2, blaOXA-10 and blaGES) and AmpC genes (blaMOX, blaCIT, blaDHA, blaACC, blaEBC and blaFOX) was performed for detection of the genes responsible for the extended spectrum cephalosporin resistance. Phenotypically ESBL production was obtained in 5/64 (7.8 %) and AmpC beta-lactamase was detected in 9/64 (14.0 %) isolates. In three isolates (Escherichia coli and Citrobacter koseri) variant of blaCTX-M gene were found to be responsible for the resistance to extended spectrum cephalosporins. Two CTX-M harboring isolates also displayed resistance to amikacin. All the five ESBL producing isolates were obtained from soil of forest region which remains undisturbed by the human activities. Thus the study provides the evidence for the presence of extended spectrum cephalosporin resistance in the soil irrespective of its exposure to anthropogenic activities. It reveals the natural phenomena of resistance development in soil microbiota.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call