Identification of staphylococcal cassette chromosome mec encoding methicillin resistance in Staphylococcus aureus isolates at Charles Nicolle Hospital of Tunis.
Staphylococcal cassette chromosome is a mobile element that carries the gene mecA mediating the methicillin resistance in staphylococci. In Staphylococcus aureus five types of SCCmec have been described, which differs in size and genetic composition among strains. SCCmec typing of 34 non redundant methicillin-resistant S. aureus (MRSA) recovered in 2004 at Charles Nicolle Hospital of Tunis was carried out. The isolates were identified by conventional methods. Methicillin resistance was detected by oxacillin and cefoxitin disks and confirmed by mecA PCR. The SCCmec complex types were determined by using PCR which amplify a sequence overlapping the right SCCmec chromosome junction. Strains were recovered mainly from cutaneous pus (61.7%) and blood cultures (17.64%). They were isolated from different wards: medicine (53.1%) especially from dermatology (41.2%); surgery (40.6%) and pediatrics (3.1%). Only two strains were community-acquired MRSA. Two strains (5.9%) were harboring SCCmec type I; five (14.7%) SCCmec type II and 27 (79.4%) SCCmec type III. The two community-acquired MRSA were harboring type II and III SCCmec, usually found in hospital acquired MRSA. Our findings indicate that there are only three SCCmec types at Charles Nicolle Hospital. However, the existence of SCCmec types II and III in community incite us to investigate more community-acquired MRSA.
Jemili-Ben Jomaa
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Laboratoire de recherche "Résistance aux Antibiotiques", service de microbiologie, faculté de médecine de Tunis, hôpital Charles-Nicolle de Tunis, boulevard du 9-Avril-1938, Tunis 1007, Tunisia.
Boutiba-Ben Boubaker
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I
Ben Redjeb
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S
D001426:Bacterial Proteins / Q000235:genetics*; D002876:Chromosomes, Bacterial; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D016106:Methicillin Resistance / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D046915:Penicillin-Binding Proteins; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification*; D014416:Tunisia
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus