Serotyping of Klebsiella pneumoniae and Its Relation with Capsule-Associated Virulence Genes, Antimicrobial Resistance Pattern, and Clinical Infections: A Descriptive Study in Medical Practice

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.