Correlation between clumping factor A gene expression in biofilm formation and antibiotic resistance among Staphylococcus aureus isolated from urine samples of Imam Khomeini Hospital, Tehran

BACKGROUND & OBJECTIVEStaphylococcus aureus causes problem in hospitals and in recent years, it has emerged as a serious agent acquired from the environment. One of the capabilities of S. aureus is the formation of biofilm, in which bacteria can exchange antibiotic resistance genes among themselves and increase the virulence of other strains of this species (S. aureus). A surface protein attached to the cell wall in S. aureus clumping factor A is a virulence factor in various staphylococcal infections.MATERIALS AND METHODSIn this study, after the Urea analysis (UA) test, the urea culture test was applied to the blood agar and Baird-Parker Agar culture media from the infectious urine samples in Imam Hospital in Tehran, S. aureus isolates were identified. Finally, molecular method was used for confirmation of identified isolates. The microtitre plate method was performed to determine the biofilm formation ability. Disk diffusion method was also used for the profiling the antibiotic resistance of the isolates.RESULTS AND DISCUSSIONIn the results of this study, out of ۱۶۰ urinary clinical samples, ۴۵ samples were positive S. aureus among which ۴۲ isolates expressed the clfA gene. Moreover, ۳۹ isolates had the ability to form biofilms in the in vitro environment. Also, among these ۴۲ isolates, the highest rate of antibiotic resistance (۸۸%) was against penicillin and the lowest resistance rate (۱۶%) was against cefoxitin. After checking with SPSS software and chi-square, there was a significant relationship between gene expression and biofilm production with antibiotic resistance (P<۰.۰۵).CONCLUSIONDue to the repeated use of antibiotics such as beta-lactams, Especially in respiratory infections and pharyngitis, the resistance of S. aureus bacteria is increasing strongly, and the formation of biofilm and virulence factors such as clfA and clfB cause concern to the World Health Organization for treatment, especially for people who they have sepsis or toxemia.

کلیدواژه ها:

Staphylococcus aureus ، clumping factors ، coagulase ، biofilm ، microtitre plate ، disk diffusion ، virulence factors