Relationship Between Antibiotic Resistance with Spa Gene Polymorphism Coding Protein A and its Typing with PCR-RFLP Technique in S. aureus Isolated from Foodstuffs

Background: Staphylococcus aureus is an important cause of hospital and community acquired infections. Food borne diseases are an important problem in public health. Protein A is a protein 42 KDa, which is expressed in all strains of this bacterium. Objectives: This study aimed to evaluate the relationship between antibiotic resistances with spa gene polymorphism. Methods: A total of 1,050 food samples were collected during 8 months in Hamedan, Iran. Food samples were evaluated for the presence of spa genes of S. aureus. The antibiotic susceptibility testing was performed using disk diffusion agar. After extraction of genomic DNA, nuc and spa genes were detected. Finally, with the PCR-RFLP method, spa typing was performed. The relationship between the antibiotic resistance rate and Spa types were analyzed by the SPSS software. Results: Results showed that the 98 cases (9.33%) of S. aureus were isolated. The most frequent resistance was observed against tetracycline (8.41%). Spa gene was reported in all isolates and 4 different patterns of spa gene was seen. Furthermore, a significant correlation between different strains isolated from diverse foodstuffs and different patterns of spa (P < 0.05) was also found. In addition, the relationship between resistance to different antibiotics with obtained types showed that there is a significant correlation between resistance to erythromycin (P = 0.014) and clindamycin (P = 0.016) with different spa types. Conclusions: In regards to the increased resistance to antibiotics in strains isolated from foodstuffs, rapid and accurate typing of S. aureus to identify transmission of the infectious organisms is very important. Molecular typing of Spa protein can prevent epidemics and reduce the infections and costs of nosocomial infections.