virulence characterization of klebsiella pneumoniae and its relation with esbl and ampc beta-lactamase associated resistance

Background and objectives: trend analysis reveals that klebsiella pneumoniae has witnessed a steep enhancement in the antibiotic resistance and virulence over the last few decades. the present investigation aimed at a comprehensive approach investigating antibiotic susceptibility including, extended spectrum beta-lactamase (esbl) and ampc β-lactamase (ampc) resistance and the prevalence of virulence genes among the k. pneumoniae isolates. materials and methods: sixty-one k. pneumoniae isolates were obtained from various clinical infections. antimicrobial susceptibility was performed by disk diffusion method. the mast® d68c test detected the presence of esbls and ampcs phenotypically, and later presence of esbl and ampc genes was observed by polymerase chain reaction (pcr). multiplex- pcr was performed to investigate various virulence genes. results: amongst 61 k. pneumoniae isolates, 59% were observed as esbl and 14.7% as ampc producers. all esbl producers were positive for blactx-m-15, while blactx-m-14 was observed in 54.1% isolates. the frequency of ampc genes was as follows: blacmy-2 (60.7%) and bladha-1 (34.4%). the most frequent virulence genes were those encoding enterobactin and lipopolysaccharide. presence of mrkd was associated with bladha-1 gene, while blacmy-2 significantly (p≤0.05) correlated with the presence of iuta and rmpa virulence genes. bladha-1 positive isolates had urine as a significant source, while blacmy-2 positive isolates were mainly collected from wound exudates (p≤0.05). conclusion: our results highlight that esbl and ampc production along with a plethora of virulence trait on k. pneumoniae should be adequately considered to assess its pathogenesis and antibiotic resistance.