The detection of the mecA gene by PCR was conducted as described previously [39]. The MIC of oxacilline The MIC of oxacilline was determined by the agar dilution method according to the Clinical and Laboratory BYL719 cost Standards Institute selleck compound guidelines (CLSI) [40]. S. aureus ATCC 29213 was used as a reference strain. Antimicrobial susceptibility testing The antibiotic susceptibility of the isolates was assessed using the disk diffusion method according to the CLSI guidelines, except for pristinamycine, which was used according to the CA-SFM guidelines. The following antimicrobial disks were tested: penicillin G (10UI), oxacillin (1 μg), ampicillin (10 μg), amoxicillin +

clavulanic acid (20/10 μg), cephalotin (30 μg), cefoxitin (30 μg), kanamycin (30 μg), gentamicin (10 μg), tobramycin (10 μg), tetracyclines (30 μg), chloramphenicol

(30 μg), ofloxacin (5 μg), ciprofloxacin (5 μg), trimethoprim + sulfamethoxazole (1.25/23.75 μg), erythromycin (15 μg), clindamycin (2 μg), vancomycin (10 μg), teicoplanin (30 μg), rifampicin (5 μg), fosfomycin (5 μg) and pristinamycine (15 μg). Culture and DNA extraction The strains were grown on TSB culture at 37°C overnight with shaking. Genomic DNA used as a target for PCR assays was extracted by using a Qiagene kit (QIAamp DNA Mini Kit (250) QUIAGEN. Sciences – US) according to the manufacturer’s instructions. SCCmec typing The SCCmec elements were typed using two multiplex PCR strategies (M-PCR1 and M-PCR2) which are used for SCCmec typing assignment, M-PCR3 was used for the J1 region difference-based subtyping, Acadesine ic50 as described previously [41]. The reference strains used were as follows: NCTC10442(type Galeterone I), N315(type II), 85/2082(type III), CA05(type IVa), 8/6-3P(type IVb), and 81/108(type IVc). Detection of the Panton-valentine

leukocidin gene The carriage of lukF-PV and lukS-PV genes encoding PVL was examined by PCR as described previously [42]. agr typing The presence of the accessory gene regulator, agr, was determined by multiplex PCR amplifying the hypervariable domain of the agr locus, as described previously [43]. PCR amplification was performed in a 50 μl reaction mixture composed of 2U of Ex Taq (Takara Shuzo Co., Ltd., Kyoto, Japan), 10 pmol of each primer, 0.2 mM deoxynucleoside triphosphate mixture, 10 ng of chromosomal DNA, 1X reaction buffer (Takara Shuzo Co., Ltd.) and H2O. Thermal cycling was set at 30 cycles (30s for denaturation at 95°C, 1 min for annealing at 55°C, and 2 min elongation at 72°C) and was performed with a Gene Amp PCR system 9600 (Perkin-Elmer, Wellesley, Massachusetts). MLST The genotypes were determined by Multilocus Sequence Typing (MLST) according to the procedure used by Enright et al [44]. The alleles of each locus were compared, and sequence types (STs) were assigned based on the S. aureus MLST database (http://​saureus.​mlst.​net/​).