Abstract

Many strains of Klebsiella pneumoniae can produce several virulence factors, such as siderophores, capsules, fimbrial adhesins and antibiotic resistance enzymes, which are important in the adherence, colonization, invasion and development of the infection. Therefore the aim of this study was to investigate ten virulence gens in 32 K. pneumoniae isolated from different clinical infections: urine (13), burns (12), sputum (4) and blood (3). Phenotypic methods were used to detect capsule, hypermucoviscosity, ability to form biofilm, produce siderophores, primary and confirmatory test of extended spectrum beta lactamase (ESBL). Polymerase chain reaction (PCR) technique was used to detect ten virulence genes encoding attachments (fimH, ycfM), siderophores (kfu: iron uptake system, entB: enterobactin, irp-2: yersiniabactin), capsule synthesis or invasions (rmpA, uge, wabG) and beta lactamase enzymes (SHV, TEM). Antimicrobial susceptibility was tested by disk diffusion method. According to phenotypic methods, the results demonstrated that, the capsule and siderophores production and biofilm formation were observed in 100% of isolates, while hypermucoviscosity phenomenon was observed in 62.5%. The most common virulence genes were fimH-1, ycfM and entB (100%), uge and TEM (93.75%), wabG and SHV (87.5%). Kfu and rpmA genes were found at medium rates of 65.62 and 62.5%, respectively and at lower prevalence was gene Irp-2 (37.5%). A rate of 84.375% of isolates showed a multidrug resistance (MDR) pattern, 12.5% extensive drug resistance (XDR), 3.12% pandrug resistance (PDR) and the rate of extended-spectrum β- lactamases (ESBL) producing K. pneumoniae was 62.5%.The study concluded that fimH-1, ycfM and entB genes were commonly found in all isolates, they seem to be at the basis of classic pathogenicity of K. pneumoniae. The most common virulence genes were observed in isolates from burns and blood samples. K. pneumoniae became highly resistant to antibiotics especially to 3rd generation cephalosporins and there was positive relationship between presence of virulence genes and ability of the bacterium to antibiotics resistance.

Key words: Klebsiella pneumoniae, drug resistance, virulence genes, Iraq.