Detection and Plasmid Profiling of Extended Spectrum Beta Lactamase Producing Escherichia coli from Diarrheic Calves

Background: Cephalosporins are major antimicrobials used to treat serious infections. However, their effectiveness is being compromised by the emergence of Extended Spectrum Beta Lactamases (ESBL). The study was aimed to perform plasmid profiling of ESBL producing Escherichia coli from diarrheic calves. Methods: A total of 104 rectal swabs were collected from diarrheic calves (Less than 1 year old) from dairy farms (buffalo calves) and gaushalas (cattle) in and around Jabalpur (M.P.). Total of 81 E. coli isolates were isolated. The ESBL screening being conducted by using cefpodoxime, ceftazidime, cefepime and aztreonam antibiotics for initial screening. The phenotypic confirmation of the ESBL producing strains was performed through ESBL phenotypic identification kit and Double Disc Diffusion Test (DDDT). While, for genotypic detection PCR was performed for bla TEM, bla CTX-M and bla AmpC. Plasmid profiling of resistant isolates was performed. Result: Out of the 81 E. coli isolated, 07 (8.64%) were phenotypically confirmed as ESBL strains. PCR amplification revealed 03 (60%) isolates positive for bla TEM (867bp) and one (20%) isolate as bla CTX-M (540bp) genes, respectively. bla AmpC gene was not detected from these isolates. Co expression of bla TEM and bla CTX-M was recorded in only one diarrheic buffalo calf. Plasmid profiling of the isolates showed that all the isolates were harboring plasmids of varying size and number. The plasmid number among the isolates ranged from 3-4 plasmids per isolate and plasmid size varied from 900bp to greater than 10kb.