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目的:弗尼斯弧菌(Vibrio furnissii)是近年来国内外学者公认的新食源性致病菌,对全球公共卫生和食品安全造成潜在威胁。鸟氨酸脱羧酶试验是区分弗尼斯弧菌和霍乱弧菌的特征性生化指标之一。利用比较基因组学寻找并利用回补试验验证二者鸟氨酸脱羧酶试验差异的分子遗传机制,为今后食品中致病微生物生化反应的基因检测提供分子依据。方法:利用比较基因组学分析弗尼斯弧菌NCTC11218和霍乱弧菌N16961在鸟氨酸脱羧代谢通路中的基因差异。随后,构建携带外源霍乱弧菌基因的弗尼斯回补菌株,利用生化条API20E验证弗尼斯野生株和回补株在鸟氨酸脱羧酶试验中的结果。结果:通过比较基因组学分析发现弗尼斯弧菌缺乏含鸟氨酸脱羧酶基因及腐胺/鸟氨酸逆向转运体基因的整个操纵子区域,弗尼斯弧菌回补株在鸟氨酸脱羧酶试验中呈现阳性。结论:推测弗尼斯弧菌在鸟氨酸脱羧试验中呈现阴性表型的遗传基础,是因其基因组中不存在完整的含有鸟氨酸脱羧酶基因及腐胺/鸟氨酸逆向转运体基因的操纵子序列。
Objective: Vibrio furnissii is recognized as a new food-borne pathogen by domestic and foreign scholars in recent years, which poses a potential threat to global public health and food safety. Ornithine decarboxylase test is to distinguish Vibnes and Vibrio cholerae one of the characteristic biochemical indicators. The use of comparative genomics to find and make use of complementary tests to verify the difference between the two ornithine decarboxylase test molecular genetic mechanism for future pathogenic microorganisms in food biochemical reactions gene testing provide a molecular basis. Methods: Genomic differences in the ornithine decarboxylase pathway were analyzed using comparative genomics of Vibrio nosocomial NCTC11218 and Vibrio cholerae N16961. Subsequently, we constructed Freund’s complement strains carrying the exogenous Vibrio cholerae gene and verified the results of Ornithine decarboxylase test using the wild strain API20E. RESULTS: Vibrio vulnificus was found by comparative genomics analysis to lack the entire operon region containing ornithine decarboxylase gene and putrescine / ornithine antiporter gene. Test positive. CONCLUSION: It is speculated that Vibrio vulnificus is the genetic basis of negative phenotype in ornithine decarboxylation test because of incomplete ornithine decarboxylase gene and putrescine / ornithine antiporter gene in the genome Operon sequence.