Antimicrobial susceptibility and SCCmec typing of methicillin-resistant Staphylococcus aureus isolates from swine
WANG Xue-min1,YAO Jian-nan1, 2,LI Bei-bei2, YANG Chuan-ding1,SHAO Dong-hua2,WANG Shao-hui2,MA Zhi-yong2
1.College of Agriculture, Hebei University of Engineering, Handan 056038, China; 2.Department of Veterinary Public Health, Shanghai Veterinary Research Institute, Shanghai 200241, China
Abstract:The purpose of the present study is to investigate the antimicrobial resistance and SCCmec typing of methicillin-resistant Staphylococcus aureus (MRSA) isolates from swine in Shanghai areas. A total of 232 samples of swine nasal swabs were collected from 5 swine farms and 1 slaughterhouse in Shanghai areas. Staphylococcus aureus were isolated by using 7.5% sodium chloride broth and CHROM agar. And MRSA isolates were identified by duplex PCR with nuc gene and mecA gene. Minimum inhibitory concentrations (MICs) of multiple antibiotics were measured by broth dilution method and the genotypes of these MRSA strains were analyzed by staphylococcal cassette chromosome mec (SCCmec). Results showed that a total of 139 S. aureus were isolated, and 70 strains were identified for MRSA and positive rate was 30.2% (70/232). These MRSA isolates were determined to be SCCmecⅣb type and no PVL gene was detected. All of the MRSA isolates were susceptible to Linezolid, Vancomycin and Amikacin. And 100% of these strains were resistant to Azithromycin, Erythromycin, Chloramphenicol, Florfenicol and Oxacillin. The resistance rates of Ceftiofur, Gentamicin and Norfloxacin were 74.3%, 62.9% and 42.9%, respectively. Interestingly, all the MRSA isolates were resistant to pleuromutilin antibiotics (Tiamulin, Valnemulin and Retapamulin). The results indicated that swine MRSA were SCCmecⅣb and were multidrug-resistant strains in Shanghai areas, especially, all of the MRSA isolates were resistant to pleuromutilin antibiotics (Retapamulin). These results also suggest that we should prevent the potential transition of resistant strains or resistant genes from animal to human, which could be through the food chains or the environment.
王雪敏,姚建楠,李蓓蓓,杨传定,邵东华,王少辉,马志永. 猪源耐甲氧西林金黄色葡萄球菌的耐药表型及其SCCmec基因分型研究[J]. 中国人兽共患病学报, 2013, 29(9): 841-845.
WANG Xue-min,YAO Jian-nan,LI Bei-bei, YANG Chuan-ding,SHAO Dong-hua,WANG Shao-hui,MA Zhi-yong. Antimicrobial susceptibility and SCCmec typing of methicillin-resistant Staphylococcus aureus isolates from swine. Chinese Journal of Zoonoses, 2013, 29(9): 841-845.
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