Study On Antibiotic Resistance Of Staphylococcus Aureus Isolated From Milk And Resistance To Beta-lactamase Antibiotics Gene

This study with microbiology and molecular biology methods separated. Identified and drug susceptibility tested in sample’s Staphylococcus aureus, which is collected from the Hohhot region Ranch, together52parts. And PCR amplification detect for screened resistant strains of beta-lactam resistance gene mecA and femA.The results show that:28Staphylococcus aureus were isolated from52samples, the cylinder plate method of drug-resistant isolates were screened, refer CLSI prescribed standards to determine the resistance, results showed that28isolates have varying degrees of resistance to eight kinds of antibiotics, of which the highest resistance rates is erythromycin and ampicillin, achieved96.4%, followed by penicillin resistance rate was89.3%, ofloxacin85.7%, streptomycin ratealso also have high resistance rate, reached71.4%, cefotaxime and norfloxacin resistance rates is lower, is35.7%,39.3%respectively, the lowest is cefazolin10.7%. Selected from the screening results of the six strains were relatively resistance ofloxacin, erythromycin, penicillin and cephalosporin cefazolin is SA2, SA5, SA8, SA13, SA20and SA24.The cylinder plate method was adopted to study the resistance of6strains; the results showed that these strains had a resistance to9kinds of antimicrobials. Among the total, Strain SA13was sensitive to cefotaxime, norfloxacin, and streptomycin, the others have a resistance; strain SA8and SA13is relatively sensitive to ofloxacin, the others has a resistance; strain SA24cephalosporin cefazolin relatively sensitive, while the others has a resistance; all test strains have a resistance for penicillin V and ampicillin.The six test strains of mecA gene detected by PCR method, the results showed only one isolates (SA24) mecA gene positive,99%homology, others are negative. FemA gene all positive, and the homology was100%.