Emergence of hypervirulent K. pneumoniae causing complicated UTI in kidney stone patients.

K. pneumoniae termed as classical K. pneumoniae (cKP) and hypervirulent K. pneumoniae (hvKP) have significant role in pathogenicity of complicated UTI (cUTI). hvKP has not been ever reported from Pakistan. This study aimed to determine the prevalence of hvKP among kidney stone patients and their association with cUTI. Total 121 urine samples were collected from two tertiary care hospitals (Poly Clinic and Pakistan Institute of Medical Sciences hospital, Islamabad). From 43.5% (53) kidney stone patients, 61 isolates of K. pneumoniae (cKP 43, hvKP 18) were confirmed through standard microbiological and biochemical characterization methods. K. pneumoniae prevalence in kidney stone patients with cUTI was 67.6% (48) (hvKP 25%, cKP 75%). All K. pneumoniae isolates were strong biofilm formers. Age was important in development of cUTI in patients of age group 31-50 years in which biofilm formation and bactericidal activity of K. pneumoniae was significant with P = 0.017 and P = 0.05 respectively. Antibiotic susceptibility was tested and 20 (33%) isolates showed Multi-drug resistance (MDR). hvKP isolated from cUTI, showed comparatively enhanced virulence attributes with multidrug resistance, suggesting their role in development of cUTI in kidney stone patients, hence there is need for whenever prescribing antimicrobial therapy in these patients, hvKP should also be focused.