大蒜提取物对猪源大肠杆菌所致小鼠腹泻的作用效果研究

Study on the effects of garlic extract on mouse diarrhea caused by swine Escherichia coli

为了探究大蒜提取物对猪源大肠杆菌所致小鼠腹泻的作用效果,笔者通过体外抑菌试验测定大蒜提取物对临床分离的猪源大肠杆菌的抑菌效果、最小抑菌浓度(MIC)和最小杀菌浓度(MBC),通过腹腔注射猪源大肠杆菌建立小鼠腹泻模型,成功建模后将小鼠分为空白组,模型组,大蒜提取物低、高剂量组,连续灌胃给药7 d,观察小鼠临床症状,测定各组小鼠死亡率、腹泻率,测定脏器指数和粪便隐血指数,并进行病理组织学分析。结果表明:试验成功分离、鉴定出猪源大肠杆菌,对大蒜提取物非常敏感,大蒜提取物对猪源大肠杆菌的MIC为31.25 mg/mL,MBC为62.5 mg/mL;与模型组相比,大蒜提取物低、高剂量组小鼠给药后采食量显著或极显著增加(P<0.05或P<0.01);大蒜提取物低剂量组小鼠第1,3,4,6,7天体重显著增加(P<0.05),大蒜提取物高剂量组小鼠第1,7天体重显著增加(P<0.05);大蒜提取物低、高剂量组小鼠肝脏指数极显著降低(P<0.01),小鼠脾脏指数显著降低(P<0.05);粪便隐血检测结果转为阴性。模型组十二指肠肠绒毛断裂变短且大量脱落,肠腺出现明显变性,黏膜中发生大量炎性细胞浸润;大蒜提取物高、低剂量组小鼠十二指肠黏膜上皮及腺体结构基本完整,固有层腺体间质有少量炎症细胞浸润。说明大蒜提取物对猪源大肠杆菌具有明显的体外抗菌作用,可有效抑制猪源大肠杆菌所致的小鼠腹泻。

In order to explore the effect of garlic extract on mouse diarrhea caused by swine Escherichia coli,the antibacterial effect,minimum inhibitory concentration(MIC)and minimal bactericidal concentration(MBC)of garlic extract on clinically isolated swine Escherichia coli were determined by bacteriostatic test in vitro.The mouse diarrhea model was established by intraperitoneal injection of swine Escherichia coli.After successful modeling,the mice were divided into blank group,model group,garlic extract low and high dose groups.The clinical symptoms of mice were observed after 7 days of continuous intragastric administration.The mortality rate,diarrhea rate,viscera index and fecal occult blood index were determined,and histopathological analysis was performed.The results showed that swine-derived Escherichia coli was very sensitive to garlic extract.The MIC of garlic extract to swine Escherichia coli was 31.25 mg/mL and the MBC was 62.5 mg/mL.Compared with the model group,the intake of mice in the low and high dose groups of garlic extract increased significantly or extremely significantly after administration(P<0.05 or P<0.01).The body weight of mice in the low-dose garlic extract group increased significantly on the 1 st,3 rd,4 th,6 th and 7 th day(P<0.05),and the body weight of mice in the high-dose garlic extract group increased significantly on the 1 st and 7 th day(P<0.05).The a low and high dose groups of garlic extract could significantly reduce the liver index of mice(P<0.01)and the spleen index of mice(P<0.05)and can make fecal occult blood test results negative.In the model group,the rupture of duodenal villi became shorter and fell off in large numbers,and the intestinal glands were obviously degenerated,and a large number of inflammatory cells were infiltrated in the mucosa.The duodenal mucosal epithelium and gland structure of mice in the high and low dose garlic extract groups were basically complete,and there was a small amount of inflammatory cell infiltration in the lamina propria glandular stroma.It indicated that garlic extract had obvious antibacterial effect on swine Escherichia coli in vitro,and could effectively inhibit mouse diarrhea caused by swine-derived Escherichia coli.