Identification and drug resistance analysis of Staphylococcus aureus isolated from yak meat in Lhasa

ObjectiveThe distribution characteristics and multiple drug resistance of staphylococcal enterotoxins(SEs) gene isolated from yak meat in Lhasa,Tibet were studied in order to provide scientific basis for the rapid identification and control of SEs in Staphylococcus aureus isolated from yak meat.MethodS. aureus was isolated from yak meat sam-ple in Lhasa by the Baird-Parker chromogenic media screening and Nuc gene PCR amplification. The distribution charac-teristics of nine common SEs genes in S. aureus were analyzed by PCR identification. And the analysis on the multiple drug resistances of SEs in S. aureus was conducted by K-B paper disk diffusion.ResultTwenty-nine strains of S. aureus were isolated from one hundred yak meat samples. The identification result of SEs genes showed that among the nine kinds of SEs genes,six kinds(SEB,SEC,SEE,SEG,SHE and SEI)were detected and three kinds(SEA,SED and SEJ) were not detected. The detection rate of SEG gene was 79.31%. The detection rate of SEC and SEI genes both were 68.97%and that of SEB gene was 55.17%. The detection rate of SHE gene was 51.72%and that of SEE gene was 3.45%. The 29 strains of S. aureus had high drug resistance rate to penicillin(P),ampicillin(AMP),claricid(CLR),erythromy-cin(E),and sulfamethoxazole(SMZ),which respectively were 79.31%,65.52%,58.62%,51.73%and 31.04%. The 29 strains of S. aureus had relatively low drug resistance rate to amikacin(AK),ticarcillin(TIM),oxacillin(OX),ciproflox-acin(CIP),and tetracycline(TE),which respectively were 10.35%,6.90%,3.45%,3.45%and 3.45%. The 29 strains of S. aureus had no drug resistance to cefoxitin(FOX),ceftazidime(CAZ),cefotaxime(CTX),gentamicin(CN),and chloramphenicol(C). The 29 strains of S. aureus showed 13 drug resistant spectrums. The multiple drug resistance rate reached 93.1%(27/29),and the main drug resistant spectrums of S. aureus strains were AMP/P,SMZ/CLR/E,and AMP/P/CLR/E.ConciusionThe S. aureus isolated from the yak meat in Lhasa contains many kinds of SEs genes such as SEG,SEC,SEI,SEB,SHE,SEE and so on. S. aureus also has strong drug resistance to many kinds of antibiotics such as penicillins,macrolides,sulfonamides and so on.