Phenotypic and molecular characterization of extended spectrum β-lactamase, AmpC β-lactamase and metallo β-lactamase producing Klebsiella spp. from farm animals in India

Animal populace has attained less attention in antimicrobial resistance research than human sector resulting in limited information available on animal origin isolates. The study aimed to investigate the occurrence of ESBL, AmpC and MBL genes, plasmids and integrons in Klebsiella spp. Fecal samples were collected from healthy livestock (cattle, pig, sheep and goat) and poultry between 2012-2015. Preliminary identification of isolates was done by conventional phenotypic methods and confirmed by genotypic methods. Antimicrobial susceptibility testing was performed by disk diffusion method. Molecular characterization by PCR was conducted for 17 antimicrobial resistance genes, 3 integrons and 18 Plasmid replicons. A total of 48 Klebsiella isolates were identified. Multidrug resistance was observed in 23% of isolates. ESBL, AmpC and MBL resistance genes were detected in 21%, 6% and 4% of isolates, respectively. Integrons [Int2 gene] and plasmids [Y and IncI genes] were identified in 6% and 8% of isolates. The study highlights the existence of ESBL, AmpC and MBL producing Klebsiella isolates with certain strains carrying mobile genetic elements in healthy livestock and poultry as reservoirs and probable disseminators of resistance, thus imposing public health threat. Prudent use of antimicrobials and continuous intensified surveillance in animal sector is crucial to limit the spread of such emerging resistant traits.