基于代谢组学分析鼠伤寒沙门氏菌感染对文昌鸡盲肠代谢的影响

Metabolomics-based analysis on the effects of Salmonella typhimurium infection on cecum metabolism of Wenchang chickens

【目的】明确鼠伤寒沙门氏菌感染后文昌鸡盲肠内容物中代谢物的变化,筛选出与沙门氏菌感染高度相关的代谢物,揭示禽沙门氏菌病对文昌鸡盲肠代谢的影响,为进一步了解及防治该病提供数据支撑。【方法】以8×10^(9)CFU/mL的鼠伤寒沙门氏菌悬液经口灌胃感染14日龄雄性文昌鸡建立禽沙门氏菌病模型,同时设健康对照组和灭活菌对照组,感染后第8 d基于代谢组学对文昌鸡盲肠内容物进行代谢物检测分析,筛选出存在显著差异的代谢物,并对差异代谢物进行KEGG通路富集分析。【结果】从文昌鸡盲肠内容物样本共鉴定出577种代谢物,在正离子(ESI+)、负离子(ESI-)模式下鉴定到的代谢物分别为417和160种。以P<0.05且权重值(VIP)>1为筛选条件,从577种代谢物中筛选出32种差异代谢物。相对于健康对照组,感染鼠伤寒沙门组存在24种差异代谢物,灭活菌对照组存在25种差异代谢物。在感染鼠伤寒沙门氏菌组中,花生四烯酸、3-(3-羟基苯基)丙酸、D-核糖、N6-乙酰基-L-赖氨酸、鸟嘌呤核苷、邻苯二酚、黄体酮、3-甲基-L-酪氨酸和4-羟基苯乙烯等9种代谢物显著升高(P<0.05,下同),而L-苏氨酸、黄嘌呤、鸟嘌呤、次黄嘌呤、尿嘧啶和酪胺等15种代谢物显著降低,以花生四烯酸含量升高最明显,其与健康对照组相比的差异倍数为8.60;KEGG通路富集分析结果显示,24种差异代谢物富集于嘌呤代谢、ABC转运蛋白、嘧啶代谢及不饱和脂肪酸生物合成等20条通路上,其中嘌呤代谢和ABC转运蛋白2条通路的富集程度达显著水平。【结论】鼠伤寒沙门氏菌感染能引起文昌鸡机体代谢紊乱,尤其是盲肠内容物中的花生四烯酸及其代谢产物或许是介导禽沙门氏菌性肠炎的关键物质,可作为解析沙门氏菌致病机制的切入点。

【Objective】To clarify the changes of metabolites in cecum contents of Wenchang chickens after Salmonella typhimurium infection,to screen out metabolites highly correlated with Salmonella infection,to reveal the effects of avian salmonellosis on cecum metabolism of Wenchang chickens,and to provide data support for further understanding and prevention of the disease.【Method】A model of avian salmonellosis was established by infecting 14-day-old male Wenchang chickens with S.typhimurium suspension of 8×10^(9) CFU/mL by oral gavage,and a healthy control group and an inactivated bacterial control group were simultaneously established.Metabolite detection and analysis based on metabolomics was performed on the cecum contents of Wenchang chickens on the 8th d after infection,and metabolites with significant differences were screened out,and the differential metabolites were analyzed by KEGG enrichment.【Result】A total of 577 metabolites were identified in cecum content samples of Wenchang chickens,and the number of metabolites identified in positive ion(ESI+)mode and negative ion(ESI-)mode were 417 and 160 respectively.A total of 32 differential metabolites were screened from the 577 metabolites using P<0.05 and weight(VIP)>1 as the screening condition.Compared to the healthy control group,24 differential metabolites were present in the S.typhimurium infected group and 25 differential metabolites were present in the inactivated bacterial control group.In the group infected with S.typhimurium,9 metabolites including arachidonic acid,3-(3-hydroxyphenyl)propionic acid,D-ribose,N6-acetyl-L-lysine,guanosine,catechol,progesterone,3-methyl-L-tyrosine and 4-hydroxystyrene exhibited significant increase(P<0.05,the same below),while 15 metabolites including L-threonine,xanthine,guanine,hypoxanthine,uracil and tyramine demonstrated significant decline.Arachidonic acid content increase was the most obvious,the its fold difference compared to the healthy control group was 8.60.KEGG pathway enrichment analysis revealed that 24 differential metabolites enriched in 20 pathways,including purine metabolism,ABC transport protein,pyrimidine metabolism and biosynthesis of unsaturated fatty acid.Of these,the purine metabolism and ABC transport protein pathways reached significant level of enrichment.【Conclusion】S.typhimurium infection can cause metabolic disorders in the body of Wenchang chickens.In particular,arachidonic acid and its metabolites in the contents of the cecum may be the key substances mediating avian salmonella enteritis.This can provide a perspective for th study of Salmonella pathogenesis.