The Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.
J Microbiol Biotechnol. 2013 Mar;23(3):422-9. doi: 10.4014/jmb.1209.09051.
The aim of this study was to investigate the characteristics of canine uropathogenic Escherichia coli (UPEC) and the interaction between canine UPEC and human bladder epithelial cells. Ten E. coli isolates collected from dogs with cystitis were analyzed for antimicrobial resistance patterns, the presence of virulence factors, and biofilm formation. The ability of these isolates to induce cytotoxicity, invade human bladder epithelial cells, and stimulate an immune response was also determined. We observed a high rate of antimicrobial resistance among canine UPEC isolates. All virulence genes tested (including adhesins, iron acquisition, and protectin), except toxin genes, were detected among the canine UPEC isolates. We found that all isolates showed varying degrees of biofilm formation (mean, 0.26; range, 0.07 to 0.82), using a microtiter plate assay to evaluate biofilm formation by the isolates. Cytotoxicity to human bladder epithelial cells by the canine UPEC isolates increased in a time-dependent manner, with a 56.9% and 36.1% reduction in cell viability compared with the control at 6 and 9 h of incubation, respectively. We found that most canine UPEC isolates were able to invade human bladder epithelial cells. The interaction between these isolates and human bladder epithelial cells strongly induced the production of proinflammatory cytokines such as IL-6 and IL-8. We demonstrated that canine UPEC isolates can interact with human bladder epithelial cells, although the detailed mechanisms remain unknown. The results suggest that canine UPEC isolates, rather than dogspecific pathogens, have zoonotic potential.
本研究旨在探讨犬源泌尿道致病性大肠杆菌（UPEC）的特性以及犬源 UPEC 与人类膀胱上皮细胞之间的相互作用。从患有膀胱炎的犬中收集了 10 株大肠杆菌分离株，对其进行了抗菌药物耐药模式、毒力因子存在情况和生物膜形成能力分析。还测定了这些分离株诱导细胞毒性、侵袭人膀胱上皮细胞和刺激免疫反应的能力。我们观察到犬源 UPEC 分离株的抗菌药物耐药率很高。在测试的所有毒力基因（包括黏附素、铁摄取和保护素）中，除了毒素基因外，均在犬源 UPEC 分离株中检测到。我们发现，所有分离株在微滴定板测定中均显示出不同程度的生物膜形成（平均 0.26；范围 0.07 至 0.82）。犬源 UPEC 分离株对人膀胱上皮细胞的细胞毒性随时间呈依赖性增加，与对照组相比，孵育 6 和 9 小时时细胞活力分别降低了 56.9%和 36.1%。我们发现，大多数犬源 UPEC 分离株能够侵袭人膀胱上皮细胞。这些分离株与人类膀胱上皮细胞之间的相互作用强烈诱导了促炎细胞因子（如 IL-6 和 IL-8）的产生。我们证明了犬源 UPEC 分离株可以与人膀胱上皮细胞相互作用，尽管详细机制尚不清楚。结果表明，犬源 UPEC 分离株具有潜在的人畜共患病性，而不是犬特异性病原体。
