Detection of Biofilm Formation Among the Clinical Isolates of Klebsiella pneumoniae: Phenotypic and Genotypic Methods

Abstract

Infections caused by biofilm-embedded pathogens decrease the efficacy of traditional treatments and increase antibiotic tolerance. Most of the human bacterial infections are biofilm-associated. Therefore, this study aimed to detect the biofilm formation among the clinical isolates of Klebsiella pneumonia collected from different hospitals in Wasit province-Iraq by phenotypic and genotypic methods. 525 clinical samples were used to isolate 77 K. pneumoniae strains from clinical specimens for five months. They were identified by microbiological method as K. pneumoniae. The microtiter plate method is used to detect the biofilm formation. Results showed that out of 77 K. pneumonia isolates, 76 (98.7%) isolates were biofilm producers with three different categories; 12 (15.6%) were weak-biofilm producers, while other isolates 63 (81.8%) and 1 (1.3%) were moderate and vigorous producers, respectively. However, 1 (1.3%) isolates were identified as nonbiofilm producers. Amplification of genes by multiplex PCR technique was done for 77 isolates of K. pneumonia to detect biofilm production genes, mrkD and FimH. Results showed that out of 77 isolates, there were 74 isolates (94.8%) positive to mrkD and 33 isolates (42.8%) to fimH. Keywords: K. pneumonia; Microtiter plate method; mrkD; fimH; Iraq.