Molecular Study of Klebsiella Pneumoniae Virulence Genes from Patients with Hospital Acquired Sepsis.

Abstract

Klebsiella pneumoniae (K. pneumoniae) is a common pathogen associated with hospital acquired infections. The presence of virulence genes and antibiotic resistance genes are known risk factors for the infection by this bacterial species. The aims of the present study were to i) investigate the coexistence of capsular genes of K. pneumoniae (rmpA and wcaG) with integron genes in clinical isolates of K. pneumoniae by polymerase chain reaction (PCR) from hospital acquired infections and to ii) correlate the presence of these genes with extended spectrum β-lactamase (ESBLs) and carbapenem-resistant phenotypes. The study included K. pneumoniae isolates from 100 patients with hospital acquired sepsis from ICUs. The isolates were subjected to antibiotic susceptibility tests by the disc diffusion method, identification of extended spectrum beta-lactamase detection (ESBLs) and carbapenemase production by specific phenotypic methods. Determination of integrons genes and capsular genes were performed by polymerase chain reaction (PCR). The most common detected virulence genes was wcaG (50%) followed by rmpA (10%). Intl1 was detected in 69% of the isolates, while intl2 and intl3 genes were not detected in any isolate. There was statistically significant association between rmpA and wcaG (p = 0.02), rmpA and intl1 (p = 0.02) and intl1 and wcaG (p = 0.0001). There was statistically significant association between wcaG, rmpA, and intl1 genes and ESBLs production as determined by double disc diffusion method (p = 0.008, p = 0.005, p = 0.05, respectively). On the other hand, only wcaG and intl1 genes had statistically significant association with carbapenemase production. The fatal outcome of the sepsis was significantly associated with the presence of wcaG, rmpA and intl1 genes (p = 0.0001, p = 0.001, p = 0.02 respectively). The study highlights a correlation between wcaG and rmpA virulence genes of K. pneumoniae with integron 1 responsible for antibiotic resistance. There is also an association between phenotypic extended spectrum beta-lactamase and carbapenemase resistance and virulence genes because the genes may be coded on the same transferable genetic elements. There was a correlation between virulence genes and outcome of infection. There is a strict need for compliance of infection control guidelines.