Determination of the Varied Resistance Abilitiesthat are Possessed by staphylococcus Aureus

Abstract

Background: Staphylococcus aureus is constantly evolving and possesses new mechanisms of resistance to antibiotics. Antibiotics that unable to eliminate bacteria may cause them to become more virulent.Effort should be continuous to find new antibiotics, and accurate diagnostic techniques and tests that are absolutely relied upon in knowing the characteristics of the diagnosed bacteria to find the appropriate treatment.

Methods:Staphylococcus aureus isolates were diagnosed by morphological, biochemical, and molecular methods. S. aureus   sensitivity to antibiotics was tested by Disk Diffusion Method and Vitek^®2  system, . Also, D-test  was performed for both food and clinical samples.

Result: The differences were found between the two tests (disk diffusion method and Vitek^®2  system) which were used to sensitivity test. Food isolateshad an inducible MLSB phenotype with  80% and clinical isolates had it with 33.3%.All S. aureus isolates hadblaZ gene. The largest percentage of isolates were having the mecA gene.

Conclusion:  There is no test can be considered absolutely accurate. Food sample isolates are the most tolerant to the altered conditions . The resistance to each one of antibiotics is controlled by many and different genes anddifferent materials then, if one of these genes became inactive, the other genes or materials can do its action.