Detection of some biofilm genes in P. aeruginosa and S. aureus isolated from clinical samples

Abstract

The biofilm an organized community of P. aeruginosa and S. aureus is usually associated with the transition from an acute to a chronic infection, and it is one of the bacteria's potent virulence factors. Aims. This study aimed to identify P. aeruginosa and S. aureus and determine whether the clinical isolates could form biofilms and their association with the biofilm genes. Methods.  122 samples were obtained from several clinical sources, and isolates were identified using morphological and biochemical tests furthermore, PCR was applied to identify the housekeeping genes (rpsLfor P. aeruginosa and 16SrRNA for S. aureus). Results.  The results verified the existence of P. aeruginosa in 36 (29.5%) and S. aureus in 25 (20.4%) of the total sample size. Using a microtiter plate assay, the isolated bacteria’s capacity to create biofilm was examined, the finding revealed that all isolates were biofilm producers with 55.5%, of P. aeruginosa and 64% S. aureus being strong biofilm producers, 30.5% and 32% were moderate producers of biofilms and 13.8% and 4% were weak producers of biofilms respectively. Additionally, a PCR assay was used to find out whether genes linked to biofilms were present (algD in P. aeruginosa and icaA in S. aureus). Conclusion. The results demonstrating that these genes were present in the isolates and were responsible for adhesion.

Keywords: P. aeruginosa, S. aureus, biofilm, algD, icaA, PCR