Objective: Klebsiella pneumoniae, one of the clinical superbugs, causes diverse infections because of its variable capsular antigens. This study focused on K. pneumoniae and aimed to assess any correlation between capsular serotype, capsule-associated virulence genes, and evaluate its resistance to conventional antibiotics in order to gain insight into any regional differences. Materials and Methods: A total of 61 K. pneumoniae collected from various clinical specimens were confirmed genotypically. Clinical and demographic data for all patients were reviewed. All isolates were subjected to antimicrobial susceptibility tests. Capsular serotyping and capsule-associated virulence genes were studied using the molecular method. Results: All typeable isolates were typed into K5, K20, and K54 serotypes, and among them, K54 was observed to be predominant. The most common capsule-associated virulence genes comprised uge (93.4%), ycfM (91.8%), and wabG (88.5%), while wcaG (29.5%) and rmpA (21.3%) were noted at much lower prevalence rates. The gene wcaG was significantly associated with K54 positive isolates (p = 0.001), while rmpA was associated with K20 positive isolates (p = 0.01). Conclusion: Serotype K54 had a high frequency in isolates collected from patients with pulmonary diseases, while serotype K20 was associated with burn patients. Carbapenems and levofloxacin were the best therapeutic options for the treatment of infections with serotypes K20 and K54.

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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). Multi- plex-PCR was performed to investigate various virulence genes. CMY-2   Results: Amongst 61 K. pneumoniae isolates, 59% were observed as ESBL and 14.7% as AmpC producers. All ESBL   CTX-M-15   producers were positive for bla   CTX-M-15   , while bla   CTX-M-14   was observed in 54.1% isolates. The frequency of AmpC genes was   CMY-2   as follows: bla   CMY-2   (60.7%) and bla   DHA-1   (34.4%). The most frequent virulence genes were those encoding enterobactin and   DHA-1   lipopolysaccharide. Presence of mrkD was associated with bla   CMY-2   DHA-1   gene, while bla   significantly (p≤0.05) correlated   DHA-1   with the presence of iutA and rmpA virulence genes. bla   positive isolates had urine as a significant source, while bla   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. pneumoni- ae should be adequately considered to assess its pathogenesis and antibiotic resistance.

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