Antimicrobial Resistance and Resistance Genes in Staphylococcus aureus and Coagulase-Negative Staphylococci Isolated from Swine

Ninety Staphylococcus strains, including 19 Staphylococcus aureus and 71 coagulase-negative Staphylococci, were isolated from different swine lymph node samples collected from Guangdong Province in 2010. Antimicrobial susceptibility testing was performed with agar dilution method according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). PCR detection was used to screen 13 resistance genes among these strains. Statistical methods were used to analyze the differences in resistance and the distribution of resistance genes in S. aureus and coagulase-negative Staphylococci. The results showed that resistance rates of S. aureus and coagulase-negative Staphylococci to macrolides, lincosamides, tetracycline were very high(＞80%). There were no significant differences of antimicrobial resistance and the carriage rates of resistance genes between S. aureus and coagulase-negative Staphylococci, except that the coagulase-negative Staphylococci strains had a higher oxacillin resistance rate and higher limA and ermB gene carriage rates as compared with S. aureus（P＜0.05）.