Detection of icaA Gene Expression in Clinical Biofilm-Producing Staphylococcus Aureus Isolates

Abstract

The pathogenicity resulting from Staphylococcus aureus infection has remarkable importance as one of the community-associated bacterial infections, due to the virulent ability of these bacteria to produce biofilms. This study was designed to detect biofilm production in clinical isolates from samples of wounds and urinary tract infections. The expression levels of the icaA gene that is responsible of slime layer production in biofilms was compared in isolates with different biofilm producing capabilities. Fifty seven samples that included 32 samples from urine and 25 samples from wounds were collected from Alwasti Hospital, Al-Kindi Teaching Hospital, and Alzahraa Clinic, Baghdad, Iraq. The bacteria was identified according to biochemical tests, API20 strip test, and PCR assay. The results of 16S rRNA PCR detection revealed that nine isolates were identified as S. aureus. The biofilm assay showed that 46.15% of the isolates were strong biofilm producers, 46.15% had moderate ability to produce biofilm, and 7.70% were weak producers. Quantitative PCR assay was carried out on three isolates with different biofilm-producing abilities. The results demonstrated that the strong biofilm-producing isolates had significantly higher (P ≤0.01) gene expression level (6.508) compared with the moderate (1.624) and the weak (1.231) isolates.

Gentamicin Upregulates the Gene Expression of hla and nuc in Staphylococcus aureus

“…The results of biofilms were in disagreement with the local study performed by Hatem et al [38] who showed 47.7% of the isolates produced a strong biofilm, 38.6% produced moderate biofilms, and 13.6% had weak biofilm. However, the results were close to Mohammed and Radif [39] who showed that 46.15 % of the isolates produced strong biofilm, 46.15 % produced moderate biofilm and 7.70 % produced weak biofilm. The differences in the results connected to the accessory gene regulatory (agr) quorum sensing system's activity.…”

Investigation of Virulence Factors in Microbial Organisms that Associated with Public Health Risk Isolates from Different Environmental Regions

“…these genes are only important for the forming of the multilayer in gram positive bacteria in the production of biofilm and PIA. However, these genes actuality related to both biofilm formation and slime [9,22,23]. The capacity of bacteria to produce biofilm is considered one of the main virulence and immune defense mechanisms.…”

The Ability of Staphylococcus aureus to Establish Biofilm on Acrylic, Plastic, and Metallic Denture Materials

“…Mohammed and Radif [38] stated that S. aureus isolates were more frequent in wounds than those of urinary tract infections and all isolates were biofilm producers. The tissue culture plate assay shows that 46.15% of the isolates were strong biofilm producer, 46.15% had moderate ability and 7.70% were weak, where the gene expression of icaA using real time PCR assay revealed a significant difference in the expression level between strong biofilm producing isolates, both weak and moderate ones.…”