Molecular Detection of Some Virulence and Antibiotic Resistance Genes of Staphylococcus aureus Isolated from Diabetic Foot Infection

Abstract Background: Diabetes mellitus is a chronic disease that continues to increase meaningfully. One of its significant complications is foot infections. Staphylococcus aureus is one of the predominant isolates in diabetic foot infections. Objectives: Determination of the severity of biofilm-forming bacteria that infect diabetic foot infections in Kerbela city by isolation of these species and diagnosis of them molecularly. Materials and Methods: In this study, Staphylococci isolated ( n = 25) from diabetic foot were identified, susceptibility test against 17 traditional antibiotics, quantification of biofilm formation was performed, screened for virulence characters by polymerase chain reaction (PCR) technique was applied for detection of five genes. Results: Among the 119 isolates obtained in this study, 25 S. aureus were identified. All the isolated S. aureus was most sensitive (84%) to levofloxacin, whereas the lowest sensitivity (36%) was toward azithromycin and erythromycin, 40% of the sensitivity was toward penicillin, amoxicillin–clavulanic acid, ceftazidime, cefepime cefotaxim, ceftriaxone, imipenem, meropenem, aztreonam, and oxacillin, and the sensitivity of both rifampin and vancomycin was 52%, and ciprofloxacin was 48%. According to the microtiter plate method, 60% of S. aureus obtained from diabetic foot infection (DFI) in the current study were strong producers of biofilm, whereas 40% of them were moderate. PCR technique detected that 60% of S. aureus contained the mec A gene and 64% contained ica A, sea , and erm C genes. Finally, 80% contained the ica D gene. Conclusions: This study displays that diabetic foot ulcer Staphylococci present resistance to antibiotics and shelter for virulence determinants. These properties propose Staphylococci can participate in the perseverance and severity of these infections, leading to treatment disappointment.