Abstract:

Objective To analyse the clinical distribution of Staphylococcus aureus and detection rate of methicillin resistant Staphylococcus aureus (MRSA), and compare the resistance of MRSA and methicillin sensitive Staphylococcus aureus(MSSA) to antibiotics. Methods Eighty isolates of Staphylococcus aureus were collected from clinical specimens from July to September in 2010. Cefoxitin disk diffusion method and polymerase chain reaction (PCR) were carried out to screen isolates of MRSA. Agar dilution was conducted to determine the minimum inhibitory concentrations (MICs) of 11 antibiotics for MRSA and MSSA, and the differences in drug resistance were compared. Results Forty-six (57.50%) isolates of MRSA were detected from 80 isolates of Staphylococcus aureus. Forty-five (56.25%) isolates of MRSA were screened after detection of mecA gene by PCR. Department of Neurosurgery (17/45, 37.78%), Department of General Surgery (7/45, 15.56%) and Emergency Observation Unit (5/45, 11.11%) were the sections with highest detection rates of MRSA. All the 80 isolates of Staphylococcus aureus were sensitive to linezolid, vancomycin and teicoplanin. However, there were significant differences in drug resistance to the other 8 antibiotics between MRSA and MSSA (P<0.05). Conclusion The detection rate and drug resistance rate of MRSA are high, which should arouse more attention from clinical departments and microbiology laboratory, so as to avoid largescale epidemics caused by nosocomial infection.

Key words: methicillin-resistant Staphylococcus aureus, minimum inhibitory concentration, mecA gene, resistance monitoring