Gao Li, He Shan, Wang Lili, Liu Yuting, Wen Tong
Faculty of Biology Science and Technology, Baotou Teachers' College, Baotou 014030, Inner Mongolia, China.
Faculty of Medical Technology and Anesthesiology, Baotou Medical College, Baotou 014040, Inner Mongolia, China.
Sheng Wu Gong Cheng Xue Bao. 2023 Apr 25;39(4):1759-1772. doi: 10.13345/j.cjb.220755.
is a common foodborne pathogen. Accidently eating food contaminated by . will cause vomiting or diarrhea, and even death in severe cases. In the present study, a . strain was isolated from spoiled rice by streak culture. The pathogenicity and drug resistance of the isolated strain were analyzed by drug sensitivity test and PCR amplification of virulence-associated gene respectively. Cultures of the purified strain were injected intraperitoneally into mice to examine their effects on intestinal immunity-associated factors and gut microbial communities, to provide references for the pathogenic mechanism and medication guidance of these spoilage microorganisms. The results showed that the isolated . strain was sensitive to norfloxacin, nitrofurantoin, tetracycline, minocycline, ciprofloxacin, spectinomycin, clindamycin, erythrocin, clarithromycin, chloramphenicol, levofloxacin, and vancomycin, but resistant to bactrim, oxacillin and penicillin G. The strain carries seven virulence-associated genes including , , , , , and , which are involved in diarrhea-causing toxins production. After infecting mice, the isolated . strain was found to cause diarrhea in mice, and the expression levels of immunoglobulins and inflammatory factors in the intestinal mucosae of the challenged mice were significantly up-regulated. Gut microbiome analysis showed that the composition of gut microbial community in mice changed after infection with . . The abundance of the uncultured_bacterium_f_Muribaculaceae in Bacteroidetes, which is a marker of body health, was significantly decreased. On the other hand, the abundance of uncultured_bacterium_f_Enterobacteriaceae, which is an opportunistic pathogen in Proteobacteria and a marker of dysbacteriosis, was significantly increased and was significantly positively correlated with the concentrations of IgM and IgG. These results showed that the pathogenic . carrying diarrhea type virulence-associated gene can activate the immune system by altering the composition of gut microbiota upon infection.
是一种常见的食源性病原体。误食被 污染的食物会导致呕吐或腹泻，严重时甚至会死亡。在本研究中，通过划线培养从变质大米中分离出一株 菌株。分别通过药敏试验和毒力相关基因的PCR扩增分析了分离菌株的致病性和耐药性。将纯化菌株的培养物腹腔注射到小鼠体内，以检查其对肠道免疫相关因子和肠道微生物群落的影响，为这些腐败微生物的致病机制和用药指导提供参考。结果表明，分离出的 菌株对诺氟沙星、呋喃妥因、四环素、米诺环素、环丙沙星、壮观霉素、克林霉素、红霉素、克拉霉素、氯霉素、左氧氟沙星和万古霉素敏感，但对复方新诺明、苯唑西林和青霉素G耐药。该菌株携带七个毒力相关基因，包括 、 、 、 、 、 和 ，这些基因参与腹泻毒素的产生。感染小鼠后，发现分离出的 菌株会导致小鼠腹泻，并且受攻击小鼠肠道黏膜中免疫球蛋白和炎症因子的表达水平显著上调。肠道微生物组分析表明，感染 后小鼠肠道微生物群落的组成发生了变化。拟杆菌门中未培养的Muribaculaceae菌属丰度显著降低，它是身体健康的一个标志。另一方面，变形菌门中的未培养的肠杆菌科细菌丰度显著增加，它是一种机会性病原体，也是菌群失调的一个标志，并且与IgM和IgG的浓度显著正相关。这些结果表明，携带腹泻型毒力相关基因的致病性 感染后可通过改变肠道微生物群的组成来激活免疫系统。
