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目的对从进口鸡翼中分离的菌株F7-10进行种属鉴定,并通过顶空气相色谱-质谱联用法(headspace gas chromatography-mass spectrometry,HS-GC-MS)分析其液态培养代谢的挥发性产物。方法通过VITEK 2 Compact全自动微生物鉴定系统分析菌株的生理生化特征,结合16S r RNA基因和prf A基因PCR扩增测序鉴定分离菌株,通过HS-GC-MS分析分离菌株F7-10代谢的挥发性产物,并与单核细胞增生李斯特菌ATCC 13932、格氏李斯特菌ATCC 700545和英诺克李斯特菌ATCC 33090的代谢挥发性产物进行比较分析。结果菌株F7-10为革兰氏阳性菌,生理生化特征与单核细胞增生李斯特菌(Listeria monocytogenes)的相似性为98%,协同溶血实验在靠近金黄色葡萄球菌的接种端溶血增强;16S r RNA基因序列与单增李斯特菌标准菌株的相似性为99%,prf A基因特异性扩增出现预期大小的目的片段。菌株F7-10在营养肉汤中代谢的挥发性产物主要有乙醇、3-羟基-2-丁酮、乙酸、丁酸、3-甲基戊酸、十二醇等,与单增李斯特菌标准菌株的代谢挥发性产物种类相似,但含量有差别。结论进口鸡翼中分离的菌株F7-10鉴定为单核细胞增生李斯特菌,该菌产生的挥发性产物可为单核细胞增生李斯特菌的鉴定提供参考。
OBJECTIVE: To identify the strain F7-10 isolated from imported chicken wing and to analyze the volatility of liquid culture metabolism by headspace gas chromatography-mass spectrometry (HS-GC-MS) product. Methods The physiological and biochemical characteristics of the strains were analyzed by VITEK 2 Compact automatic microbial identification system. The strains were identified by PCR amplification of 16S rRNA gene and prf A gene. The volatile components of F7-10 were analyzed by HS-GC-MS. The products were compared with the metabolic volatiles of Listeria monocytogenes ATCC 13932, Listeria monocytogenes ATCC 700545 and Listeria sinensis ATCC 33090. Results The strain F7-10 was a Gram-positive bacterium. The biochemical characteristics of the strain F7-10 were 98% similar to those of Listeria monocytogenes. The co-hemolytic assay increased hemolytic activity near the inoculation end of Staphylococcus aureus. The 16S The similarity of the r RNA gene sequence with the standard strain of Listeria monocytogenes was 99%. The prf A gene specifically amplified the target fragment of expected size. Strain F7-10 metabolites in nutrient broth volatile products are mainly ethanol, 3-hydroxy-2-butanone, acetic acid, butyric acid, 3-methylpentanoic acid, dodecanol, etc., and Listeria monocytogenes The standard strains of volatile metabolites of similar species, but the content is different. Conclusion The strain F7-10 isolated from chicken wing was identified as Listeria monocytogenes. The volatile products produced by this strain could provide a reference for the identification of Listeria monocytogenes.