Galarce Nicolás, Escobar Beatriz, Sánchez Fernando, Paredes-Osses Esteban, Alegría-Morán Raúl, Borie Consuelo
Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, 8820808 Santiago, Chile.
Instituto de Salud Pública de Chile, Departamento de Salud Ambiental, 7780050 Santiago, Chile.
Animals (Basel). 2019 Sep 27;9(10):733. doi: 10.3390/ani9100733.
Shiga toxin-producing (STEC) is a zoonotic pathogen that causes severe illness in humans and is an important cause of foodborne disease. In Chile, there is limited information on the virulence characteristics of this pathogen in livestock, and none in companion animals. The aim of this study was to characterize STEC strains isolated from cattle, swine, dogs, and cats, in Chile, in terms of the presence of Shiga toxin types and subtypes, virulence genes, serogroups, and clonality. One-thousand two-hundred samples were collected, isolating 54 strains (4.5%), where 1a (68.5%) and A (74.1%) were the most frequently detected virulence genes. Only one strain belonging to the most clinically relevant serogroups was identified. Pulsed field gel electrophoresis analysis showed high clonal diversity among strains isolated from cattle, while those from swine showed the same pattern. This study provides further evidence regarding cattle and swine in Chile as a potential source of a wide variety of STEC strains that could potentially cause severe illness in humans, and that companion animals do not seem to represent a relevant reservoir. It also argues that preventive and control strategies should not be focused on detecting serogroups, but instead, on detecting their determinants of virulence.
产志贺毒素大肠杆菌（STEC）是一种人畜共患病原体，可导致人类严重疾病，是食源性疾病的重要病因。在智利，关于这种病原体在牲畜中的毒力特征的信息有限，而在伴侣动物中则没有相关信息。本研究的目的是根据志贺毒素类型和亚型、毒力基因、血清群和克隆性的存在情况，对从智利的牛、猪、狗和猫中分离出的STEC菌株进行特征描述。共收集了1200份样本，分离出54株菌株（4.5%），其中1a（68.5%）和A（74.1%）是最常检测到的毒力基因。仅鉴定出一株属于临床相关性最高的血清群的菌株。脉冲场凝胶电泳分析显示，从牛中分离出的菌株具有高度的克隆多样性，而从猪中分离出的菌株呈现相同的模式。本研究进一步证明，智利的牛和猪是多种可能导致人类严重疾病的STEC菌株的潜在来源，而伴侣动物似乎不是相关的储存宿主。研究还表明，预防和控制策略不应侧重于检测血清群，而应侧重于检测其毒力决定因素。
