Study of Various Virulence Genes, Biofilm Formation and Extended-Spectrum β-lactamase Resistance in Klebsiella pneumoniae Isolated from Urinary Tract Infections

The aims of the current study were to evaluate the capacity of K. pneumoniae isolated from hospital-acquired urinary tract infection to form biofilm, the relation of this capacity to various virulence genes and the prevalence of Extended Spectrum β-lactamases (ESBL) among these isolates by phenotypic and genotypic methods.

The study included 100 non-duplicate strains of K. pneumoniae isolated from 100 different urine samples from patients with hospital-acquired urinary tract infection. The isolated strains were studied for biofilm formation, ESBL production by phenotypic methods. Molecular studies were applied for the detection of ESβLs genes bla_TEM, bla_SHV, bla_CTX-M and for detection of virulence genes fimH, uge, rmpA, mag A, wzy, kfa and aerobactin genes.

The majority of the isolates had the capacity to form a biofilm (81%), with ESBL prevalence rate 41%. The most prevalent gene among ESBL producing K. pneumoniae was bla_CTX-M (73.2%) followed by bla_SHV (53.6%) and bla_TEM (51.2%). Among the virulence genes studied in K. pneumoniae isolates, the most prevalent gene was fimH (76%), uge (70%). There was significant association between ESBL production, and resistance to amikacin, cefepime, ceftazidime, gentamicin, imipenem and meropenem and biofilm production in K. pneumoniae isolates. There was significant association between bla_CTX-M, bla_SHV, fimH, mag, kfa, wzy, rmpA and aerobactin and biofilm production in K. pneumoniae.

The present study highlights the prevalence of virulence genes among biofilm-forming strains of K. pneumoniae isolated from hospital-acquired urinary tract infection. Moreover, there was association between biofilm formation and ESBL production. Further studies are required to elucidate the clinical impact of the association of these different mechanisms.