aureus in Nigeria is based on phenotypic testing especially the disk diffusion technique but recent studies have relied on the PCR detection Captisol purchase of the mecA gene for the identification and confirmation of MRSA [23–26]. However, no information is available on the nature of antibiotic resistance genes of S. aureus

in Nigeria. Our present study provides baseline information on antibiotic resistance and molecular epidemiology of MSSA and MRSA in Nigeria. Results Antibiotic susceptibility testing and detection of antibiotic resistance genes in S. aureus isolates The 68 S. aureus isolates obtained between January and April 2009 were analyzed for antimicrobial resistance (Table 1). All the isolates were susceptible to teicoplanin, vancomycin, phosphomycin, fusidic acid, rifampicin, daptomycin, mupirocin, linezolid and tigecycline, and two isolates were susceptible to all the antibiotics tested. In addition to the antibiotics stated above, all MSSA isolates (84%) were susceptible to clindamycin and moxifloxacin and less than 4% were resistant to erythromycin, 21.1% to ciprofloxacin, 47% to tetracycline, 68% to cotrimoxazole and 86% to penicillin. The predominant antibiotypes among the MSSA isolates

were resistance to penicillin, tetracycline and cotrimoxazole (15 isolates), and resistance to penicillin and cotrimoxazole (13 isolates). A total of 11 isolates were resistant to oxacillin and

confirmed H 89 mouse as MRSA based on the detection of the mecA gene (Table Rebamipide 1). The ermA gene was identified in all erythromycin-resistant MRSA isolates, while two erythromycin-resistant MSSA isolates possessed the msrA gene. All the gentamicin-resistant isolates carried the aacA-aphD gene. Moreover, the tetM gene was detected in 11 isolates (7 MRSA and 4 MSSA) and the tetK gene was present in 4 MRSA and 23 MSSA isolates. SCCmec typing The SCCmec type V was identified in four MRSA isolates obtained in Ile-Ife, Ibadan and Lagos, while one MRSA isolate from Ile-Ife possessed the SCCmec type IV element (Table 2). The MRSA isolates from Maiduguri were non-typeable for the SCCmec element based on established KPT-330 datasheet protocols [9, 27], and no amplification was observed for the ccrA, ccrB, and ccrh genes. However, these MRSA isolates possessed the ccu gene. The comparison and analysis of the ccu sequences from two selected MRSA isolates in this group with sequences in the GenBank suggested that the MRSA isolates possessed an SCCmec type III element of uncommon organization, which had not been identified using standard protocols.