Detection and characterization of extended-spectrum beta-lactamase genes ( bla TEM and bla SHV ) among beta-lactam-resistant fecal coliforms of dairy cattle from Chhattisgarh, India

The aim of this study was to isolate the antimicrobial-resistant enterobacteria from cattle feces and to identify the extended-spectrum beta-lactamase (ESBL) and carbapenemase gene among them. A total of 70 cattle fecal swab samples were collected from Durg, Chhattisgarh, India, and cultured in nutrient broth. Bacterial isolation recovered 120 gram-negative bacteria. Antimicrobial susceptibility testing showed 90 (75%) coliform isolates (66 Escherichia coli , 20 Klebsiella sp., and two each of Enterobacter sp. and Citrobacter sp.) resistant to amoxicillin, amoxicillin-clavulanic acid, cefixime, ceftazidime, imipenem, or meropenem. Bacterial isolates showed the highest resistance rate for ceftazidime (61.6%), followed by cefixime and amoxicillin-clavulanic acid (60%). The ESBL phenotype, assessed by combination disk method, was shown by 36 (40%) of the resistant isolates. PCR amplification revealed 20% and 31.6% positivity of bla T E M " role="presentation"> T E M T E M _{TEM} and bla S H V " role="presentation"> S H V S H V _{SHV} genes, respectively. bla T E M " role="presentation"> T E M T E M _{TEM} and bla S H V " role="presentation"> S H V S H V _{SHV} coexpression was recorded among eight (12.1%) E. coli and two (10%) Klebsiella sp. isolates. Restriction endonuclease analysis indicated clonal blaTEM and clonal and nonclonal blaSHV genes. Nucleotide sequencing confirmed the bla T E M " role="presentation"> T E M T E M _{TEM} and bla S H V " role="presentation"> S H V S H V _{SHV} genotypes. None of the isolates showed amplification of the carbapenemase gene. Phenotypic and genetic detection and characterization of ESBLs among Enterobacteriaceae bacteria illustrate the importance of planning and execution of effective control programs for emerging antimicrobial-resistant pathogens.