Détection de la première souche de Staphylococcus aureus de sensibilité diminuée aux glycopeptides à l’hôpital la Rabta de Tunis

Since the advent of the first glycopeptide intermediately susceptible Staphylococcus aureus (GISA) and its heterogeneous variant hGISA in 1997, debate still ensues as their clinical significance. We report here the first case of GISA in Rabta hospital of Tunisia. Antimicrobial resistance was determined by the disk diffusion method in accordance with CA-SFM (Comity of Antibiogramm of French society of Microbiology). The MIC of vancomycin and teicoplanin was determined by E-test. The detection of mec A gene, virulence factors genes and agr groups (1-4) was performed by multiplex PCR. spa types were determined with the assistance of Ridom of Staph Type software (Ridom GmbH, Wurburg, Germany). The allelic profiles of MRSA were assigned on the basis of their MLST type using the eBURST program. A MRSA bacteraemia patient was treated with teicoplanin for 14 days. S. aureus isolated from patient's blood culture was identified as MRSA and GISA with teicoplanin MIC of 16 mg/l. The molecular study of this strain showed that it belongs to the clonal complex CC8 and is attached to the iberian clone (agr1, enterotoxin A, ST 247, spa type t052). Clinicians and laboratories alike are increasingly aware that patients on long-term vancomycin therapy may signal the presence and potential spread of hGISA/GISA strains. hGISA/GISA strains emerged from lineages with agr types I and II. The multiresitance of the Iberian clone ST247 could be explained by the presence of several resistance genes.