Methicillin-resistant Staphylococcus aureus (MRSA) represents the severe causal agent in nosocomial infections that are becoming increasingly difficult to cure due to their emerging resistance to all current antibiotic classes. The aim of this study is to determine the frequency of MRSA strains and GISA as well as resistance profile to different families of antibiotics. 67 strains of MRSA are isolated from different pathological origins. The isolation and the identification of S. aureus strains were based on conventional methods. The resistance to methicillin of these strains was detected by the method of disk diffusion in Mueller-Hinton and a screening by oxacillin (6 μg/ml). Furthermore, a study of the resistance of these strains to different families of antibiotics is done. Decreased sensitivity to glycopeptides of suspected strains was confirmed after determination of the MIC to vancomycin by E-test. The study has shown that 67 strains resistant to methicillin were identified among the 150 strains isolated (44,6%). The MRSA were isolated from pus (71, 6%), urine (17, 9%) and vaginal samples (10,4%). These MRSA strains expressed resistance to different antibiotic families. We identified two MRSA strains (M04 and M47) showing reduced glycopeptides susceptibility. Since the multi-drug resistant MRSA strains are not negligible, a regular supervision is necessary. The "GISA" is an observation phenomenon that should better be defined in terms of detection and prevalence.