创伤弧菌经食管感染小鼠的致病性

Pathogenicity of Vibrio vulnificus infection in mice through enteron

目的:探讨创伤弧菌(Vibriovulnificus,Vv)经食管感染小鼠的致病特点.方法:39只SPF级昆明小鼠(雌性20只,雄性19只),实验组24只,均强制性喂食Vv菌液(4.7×1010cfu/L,菌株编号1.1758)0.6mL/只;对照组15只,喂食灭菌培养基(含35g/1Nacl的碱性蛋白胨水)0.6mL/只.观察小鼠一般情况,分别于实验后12、32及72h各处死8只实验组小鼠和5只对照小鼠,取其食管、胃及肠组织进行病理学观察,同时进行Vv分离培养,并取胃组织进行扫描电镜观察.另外用强酸及低盐处理Vv菌后,行光镜观察及增菌培养.结果:Vv经食管感染小鼠后并未导致其出现呕吐、腹泻等消化道症状,且Vv的分离培养结果均为阴性,但病理学及扫描电镜结果显示实验组小鼠胃黏膜表面附着有极度肿胀变形的Vv菌体,且附着处部分胃黏膜上皮细胞脱落、溶解坏死.强酸低盐处理过的Vv部分肿胀变形,且增菌培养结果为阴性.结论:Vv在正常小鼠的胃酸环境中不能存活,难以进入肠道繁殖,通常不引起小鼠呕吐和腹泻症状,但可轻度损伤小鼠胃黏膜上皮;1.1758Vv株属消化道感染弱毒力株.

AIM: To characterize the Vibrio vulnificus (Vv) infection transmitted through the alimentary canal in mice. METHODS: Thirty-nine KM mice (SPF) were divided randomly into 2 groups: the study group (n = 24) and the control group (n = 15). The model of alimentary canal transmitted Vv infection was established by feeding each mouse with 0.6 mL(4.7×1010cfu/L) Vv inoculum (strain 1.1 758). The mice in the control group were fed with sterile culture medium. The pathological changes of the alimentary canal were examined under microscope. Vv taken from the tissues was cultured. The morphology of Vv in acid (close to the gastric juice) and at low salinity (9 g/L NaCl) was also examined. RESULTS: No digestive symptom such as vomiting or diarrhea was observed in the mice fed with Vv. The Vv culture results of the tissues were negative. However, degeneration and necrosis of the epithelial cells were observed in the gastric mucosa. Anamorphic and swollen Vv was found in the stomach under microscope in the study group. Vv processed in acid and low salt was also anamorphic and swollen. CONCLUSION: Vv cannot survive in the acidic gastric juice with low salinity naturally, but it can still induce acute injury of the gastric mucosa. Vv strain 1.1 758 infected via enteron has a mild pathogenicity in the gastric mucosa.