The University of Tennessee College of Veterinary Medicine, Department of Small Animal Clinical Sciences and Biomedical and Diagnostic Sciences, Knoxville, TN, United States.
Virginia-Maryland College of Veterinary Medicine, Department of Biomedical Sciences and Pathobiology Blacksburg, VA, United States.
Vet Parasitol. 2019 Sep;273:90-96. doi: 10.1016/j.vetpar.2019.08.012. Epub 2019 Aug 20.
Tritrichomonas foetus is a common cause of large bowel diarrhea in cats. Probiotics have been suggested to be effective for many intestinal pathogens; however, there are a lack of studies evaluating the effect of probiotics in T. foetus infection. In vitro studies were performed to evaluate the effect of a probiotic containing Enterococcus faecium (Efm) SF68 and a novel probiotic, Enterococcus hirae, on the inhibition of T. foetus growth, adhesion to, and cytotoxicity towards the intestinal epithelium. The effect of enterococci on T. foetus proliferation during co-culture was evaluated throughout log phase T. foetus growth. The previously validated in vitro co-culture model system using porcine intestinal epithelial cells (IPEC-J2) was used to evaluate the effect of enterococci on T. foetus adhesion and cytotoxicity towards intestinal epithelial cells. Cytotoxicity was assessed using fluorescent microscopy and spectrophotometry. Interactions of T. foetus, enterococci, and intestinal epithelial cells were assessed using scanning electron microscopy and immunofluorescence assays (IFA). Enterococcus-induced inhibition of T. foetus growth was demonstrated at concentrations as low as 10 enterococci colony forming units (CFU)/mL and was dependent, in part, on environmental pH and the presence of viable enterococci organisms. T. foetus adhesion, including with a ronidazole-resistant strain, was reduced with pretreatment of intestinal epithelial cells with enterococci but was not significantly affected when enterococci were introduced simultaneously or following T. foetus infection. Compared to Efm, E. hirae more effectively decreased T. foetus adhesion, suggesting its superior potential as a novel probiotic for T. foetus infection. There was no effect of enterococci treatment on T. foetus-induced intestinal epithelial cell cytotoxicity. Our results support further study into the investigation of a possible benefit of enterococci-containing probiotic treatment for prevention of T. foetus infection in at-risk uninfected cats.
胎儿弯杆菌是猫大肠性腹泻的常见病因。益生菌已被证明对许多肠道病原体有效；然而，缺乏评估益生菌对胎儿弯杆菌感染影响的研究。进行了体外研究，以评估含有屎肠球菌（Efm）SF68 和新型益生菌屎肠球菌的益生菌对抑制胎儿弯杆菌生长、黏附以及对肠上皮细胞的细胞毒性的影响。在胎儿弯杆菌对数生长期的整个生长过程中，评估了肠球菌对共培养中胎儿弯杆菌增殖的影响。使用先前经过验证的猪肠上皮细胞（IPEC-J2）体外共培养模型系统，评估了肠球菌对胎儿弯杆菌黏附以及对肠上皮细胞细胞毒性的影响。使用荧光显微镜和分光光度法评估细胞毒性。使用扫描电子显微镜和免疫荧光分析（IFA）评估胎儿弯杆菌、肠球菌和肠上皮细胞之间的相互作用。证明了肠球菌在低至 10 个肠球菌菌落形成单位（CFU）/mL 的浓度下即可抑制胎儿弯杆菌的生长，并且部分依赖于环境 pH 值和有活力的肠球菌的存在。用肠球菌预处理肠上皮细胞可减少胎儿弯杆菌的黏附，包括对甲硝唑耐药株的黏附，但当肠球菌同时或在胎儿弯杆菌感染后引入时，黏附则无明显变化。与 Efm 相比，E. hirae 更有效地减少了胎儿弯杆菌的黏附，表明其作为胎儿弯杆菌感染新型益生菌具有更好的潜力。肠球菌处理对胎儿弯杆菌诱导的肠上皮细胞细胞毒性没有影响。我们的研究结果支持进一步研究，以调查含肠球菌益生菌治疗对预防高危未感染猫胎儿弯杆菌感染的可能益处。
