DISTRIBUTION OF A METHICILLIN-RESISTANCE GENE IN URINARY ISOLATES OF METHICILLIN-RESISTANT STAPHYLOCOCCI EXAMINED BY ENZYMATIC DETECTION OFTHE POLYMERASE CHAIN-REACTION

We tried to examine the susceptibility to various antimicrobial agents and to detect the mec A gene using enzymatic detection of the polymer ase chain reaction in methicillin-resistant Staphylococcus aureus (MRS A), methicillin-sensitive Staphylococcus aureus (MSSA) and Staphylococ cus epidermidis isolated from patients with complicated urinary tract infections (UTIs). All the strains of MRSA and MSSA showed a low sensi tivity to imipenem (IPM), ceftazidime (CAZ), flomoxef (FMOX), amikacin (AMK), ciprofloxacin (CPFX) and ofloxacin (OFLX), Although all the st rains of MRSA had the mec A gene, none of the MSSA strains had it, 74% of S. epidermidis had the mec A gene and strains resistant to methici llin were seen in 72% of them. The mec A-positive S. epidermidis showe d a lower susceptibility to IPM, CAZ, FMOX, AMK, CPFX and OFLX than th e mec A-negative strains, These results suggest that methicillin resis tance was due to the mec A gene in MRSA and methicillin-resistant S. e pidermidis (MRSE), and that MRSEs were very common among the bacteria causing complicated UTI. When we try to control nosocomial infections due to MRSA, it should also be noted that MRSE can be a reservoir of t he mec A gene.