了解猪肉中单核细胞增生李斯特菌的污染情况、血清型和耐药性现状。按照国标GB 4789.30-2010程序分离猪肉中单核细胞增生李斯特菌；多重PCR确定血清型；纸片扩散法检测单核细胞增生李斯特菌对抗生素的敏感性。研究结果表明273份猪肉样本中有52（19.02%)个受单核细胞增生李斯特菌的污染，共检出78株该致病菌。33株（42.31%）、24株（30.71%）、16株（20.51%）、3株（3.85%）、2株（2.56%)分别被确定为血清型1/2a（或3a）、1/2b（或3b或7）、1/2c（或3c）、4a（或4c）和4b（或4d或4e）。所有菌株对氨苄西林、 氨苄西林/舒巴坦、亚胺培能、环丙沙星、左氧氟沙星、万古霉素都敏感，对四环素（20.51%）的耐药率最为严重。11.54%的菌株对临床治疗李斯特菌病的青霉素、庆大霉素、红霉素等抗生素出现耐药。tet(M)基因是单核细胞增生李斯特菌耐四环素的主要机制之一，接合型转座子Tn916与该菌四环素耐药散播有直接关系。

To investigate the pork contamination by Listeria monocytogenes, its susceptibility to antimicrobial agents and serotypes, all strains were isolated by the GB 4789.30-2010 method; L. monocytogenes serotypes were identified by PCR; and antibiotic resistant profile of the isolates was examined using disc diffusion assay. A total of 273 pork samples were examined, out of which 52 samples (19.02%) were positive for L. monocytogenes and 78 strains were detected. And 33 (42.31%), 24 (30.71%), 16 (20.51%), 2 (2.56%), 3 (3.85%) of the isolates were identified as serotypes 1/2a (or 3a), 1/2b (or 3b or 7), 1/2c (or 3c), 4a (or4c)and 4b (or 4d or 4e), respectively. With disc diffusion assay, all strains were susceptible to the antibiotics, including ampicillin, ampicillin-sulbactam, imipenem, ciprofloxacin, levofloxacin, and vancomycin. However, the percentages of tetracycline resistances were higher. 11.54% isolates were resistant to penicillin, gentamicin, erythromycin. The conjugative transposon Tn916 is the important determinants of the resistance in spreading of the L. monocytogenes.

华南理工大学中央高校基本科研业务费专项资金资助项目(2012ZZ0083)；国家自然科学基金青年科学基金项目（31201363）；广州市科技计划项目（11C12080718）