[Methicillin resistant Staphylococcus aureus: phenotypic and genotypic studies].

BACKGROUND

Staphylococcus aureus is a human opportunistic pathogen. Its important pathogenicity and the increasingly rate of resistance to methicillin are the main causes of morbidity and mortality.

AIM: In order to evaluate the epidemiologic situation of Methicillin Resistant S. aureus (MRSA) at Charles Nicolle hospital.

METHODS

A four years retrospective study (January 1999-December 2002) was conducted.

RESULTS

65 non redundant MRSA isolates were collected. Identification was based on morphology, culture and biochemical characters. Antibiotic susceptibility was determined by disk diffusion method. Resistance to methicillin was confirmed by mec A PCR. Molecular typing was performed by Random Amplified Polymorphic DNA using ERIC-IR. Despite a perfect biotypic similarity between strains, ERIC-IR PCR revealed 7 genotypes.

CONCLUSION

The combination of phenotypic methods and RAPD fingerprinting were easy to perform routinely for MRSA typing. However, phylogenetic relationship between strains needs more investigations.