Molecular Detection of Biofilm related Genes in Staphylococcus aureusIsolated from UTI Patients in Baghdad City

Abstract

The increase in the prevalence of resistance to antibiotics among pathogenic bacteria is a severe danger to public health predicated to cause almost five million fatalities. Staphylococcus aureus is one of the most efficient pathogens that can form biofilm. The infection resulting from this bacterium's biofilm is considered a serious problem, as it is difficult to treat it with traditional antibiotics.The current study was conducted to estimate the prevalence of some biofilm-mediated genes of S. aureus collected from urinary tract infections, to detect their ability to construct biofilms, and to determine their resistance to antibiotics.The S. aureus isolates were obtained from patients with urinary tract infections in different local hospitals in Baghdad city. The antibiotic susceptibility pattern toward twenty antibiotics and quantitative assays for biofilm construction was performed for all bacterial isolates. Moreover, a multiplex polymerase chain reaction (PCR) was adopted to detect the prevalence of six targeted genes (fib, eno, sdrC, bap, clfA and clfB).The results of the antibiotic susceptibility pattern indicated that most isolates exhibited resistance to Benzylpenicillin, oxacillin, Erythromycin, Piperacillin/Tazobactam and Tetracycline. In contrast, all isolates were susceptible to Gentamicin, Tigecycline and Linezolid. The multidrug resistance characteristics appeared in all isolates under the study that were resistant to at least three or more distinct classes of antibiotics. Furthermore, the result revealed that most isolates produced strong and moderate biofilms, 42.42% and 48.48%, respectively; meanwhile, 6.06% and 3.03% of the isolates were formerly weak, non-biofilms. The presence of the fib gene was detected in 90.9% of the isolates, while the eno and sdrC genes were observed in all the isolates 100%.  In contrast, the bap gene did not appear in any of the isolates 0%. In addition, the prevalence of clfA and clfB in isolates under investigation was 90.9% and 87%, respectively. In conclusion, the ability to develop biofilms is an efficient strategy that may contribute to preventing antimicrobial agents from overcoming S. aureus, as all isolates are multidrug-resistant and have a high percentage of strong biofilm producers. In addition, the high prevalence of some biofilm-associated genes highlights their crucial role in biofilm development in these pathogenic bacteria. It provides an insight into the relation between biofilm formation and multidrug resistance to different classes of antibiotics.