Estimation of the Role of Mrk Genes in Klebsiella pneumoniae Isolated from River Water and Clinical Isolates

Klebsiella pneumoniae is a member of Enterobacteriaceae, which causes many infectious diseases including blood, lung, wound, burn, and urinary tract infections. It is found in sewage and river water as a coliform bacterium. This study aimed to find the prevalence and correlation among Mrk operon genes that express adhesion properties in both environmentally and clinically isolates. Twenty skin isolates of K. pneumoniae were collected from the wound and burn infections as swab samples. Fifteen samples of river water were obtained from the Diyala river and K. pneumoniae was isolated. The diagnosis was applied by characteristics on culture media and assured by VITEK 2 system with 16s rRNA gene, then the DNA was extracted, and concentration and purity were measured for each isolate. PCR technique was performed to detect five genes of Mrk genes: MrkA, Mrk B, Mrk C, Mrk D and Mrk F. Findings illustrated that 10 of 15 water samples that contained Klebsiella besides the confirmed 20 clinical K. pneumoniae isolates express Mrk operon of the heterogeneous pattern. In clinical isolates, the percentages of Mrk genes (Mrk A, Mrk B, Mrk C, Mrk D, and Mrk F) were 75, 85, 80, 50 and 60%; while in environmental samples, they were 40, 60, 50, 20 and 40%, respectively, as the clinical isolates showed the largest occurrence of Mrk genes. A significant relationship was detected between the source of bacterial isolation and the prevalence of target genes (0.0039) at P≤ 0.01. The Mrk genes showed no correlation among them in water samples, except that recorded between MrkB and MrkC, which was 0.028 at P≤ 0.01. However, Mrk genes had a significant correlation at P≤ 0.01 and 0.05 among them in swab samples since they expressed more virulence persistence with high attachment in local skin infections, compared to river isolates.