Abstract

The aim of this study was to detect different genotypes of methicillin resistantStaphylococcus aureus (MRSA) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the spa gene in Cairo University hospital. A total of 48 samples were obtained from the sputum, infected wound, blood and pleural fluid from Cairo University hospital from the main microbiology laboratory for three month duration, they were then processed, cultured and subsequently susceptibility test was performed using disc diffusion method. The strains were investigated by cefoxitin 30 µg disk diffusion method. PCR was used to detect mecA gene, and to amplify sequence of spa gene, and the PCR products were analyzed by PCR-RFLP usingHaeII restriction enzyme. A total of 48 samples were obtained from the sputum, infected wound, blood and pleural fluid from Cairo University hospital from the main microbiology laboratory for three month duration. 37 (77%) isolates were resistant to cefoxitin, all tested isolates gave PCR positive for mec A gene, PCR-RFLP of the spa gene showed 18 (37.5%) isolates with pattern I, one of them showed pattern I, II, IV together. 8 (16.6%) isolates showed pattern II, one of them showed pattern I, II, IV; 9 (18.7%) isolates showed pattern III, 3 (6.2%) isolates showed pattern IV; one of them showed pattern I, II, IV; 8 (16.6%) isolates showed pattern V. 2 (4%)isolates were negative, and 1 isolate showed bands at 243, 667, 715 and 811 bp, 1 isolate showed bands at 243, 264 and 739 bp. PCR-RFLP typing method is a good practical tool in routine epidemiological surveillance. It's easy in performance and interpretation, and it can replace PFGE which is time-consuming and expensive.

Key words: Methicillin-resistant Staphylococcus aureus, mecA gene, spa gene, restriction fragment length polymorphism (RFLP)