Loor-Giler Anthony, Robayo-Chico Marcela, Puga-Torres Byron, Hernandez-Alomia Fernanda, Santander-Parra Silvana, Piantino Ferreira Antonio, Muslin Claire, Nuñez Luis
Laboratorios de Investigación, Dirección General de Investigación, Universidad de las Américas (UDLA), Antigua Vía a Nayón S/N, Quito EC 170124, Ecuador.
Facultad de Ingeniería y Ciencias Aplicadas, Carrera de Ingeniería en Biotecnología, Universidad de Las Américas (UDLA), Antigua Vía a Nayón S/N, Quito EC 170124, Ecuador.
Foods. 2025 Jan 27;14(3):410. doi: 10.3390/foods14030410.
(), especially the Shiga toxin-producing O157:H7 strain, poses severe health risks. In rural Ecuador, raw milk consumption heightens contamination risks. This study analyzed 633 raw milk samples from Pichincha and Manabí to assess O157:H7 prevalence. The samples were enriched using BHI broth, and then specific culture media were used to isolate O157:H7. The pathogen in the enriched raw milk was identified, and the isolates were specifically confirmed through the application of a newly designed qPCR assay. The novel qPCR assay demonstrated remarkable sensitivity, capable of detecting up to one copy of genetic material, and specificity (no amplification of other bacteria). An extremely high O157:H7 prevalence of 0.63 (n = 401) was detected, where the province with the highest number of positive samples was Manabí with 72.8% (n = 225/309) and 54.3% (n = 179/324) for Pichincha. In both provinces, the presence of O157:H7 contamination exhibited a favorable correlation with small-scale farms and elevated temperatures. This research provides valuable data on the microbiological contamination of O157:H7 present in raw milk, in addition to an improved method that has been demonstrated to be faster, more sensitive, and more specific than conventional and previously published methods, highlighting the associated risk of food-borne infections and pointing out potential shortcomings in the regulation of agricultural practices and the need for periodic monitoring of bacterial contamination levels with updated methods.
（），尤其是产志贺毒素的O157:H7菌株，会带来严重的健康风险。在厄瓜多尔农村地区，饮用生牛奶会增加污染风险。本研究分析了来自皮钦查省和马纳比省的633份生牛奶样本，以评估O157:H7的流行情况。样本先用脑心浸液肉汤进行增菌，然后使用特定的培养基分离O157:H7。对增菌后的生牛奶中的病原体进行鉴定，并通过应用新设计的qPCR检测法对分离株进行特异性确认。这种新型qPCR检测法显示出极高的灵敏度，能够检测到低至一份遗传物质拷贝，且具有特异性（不会扩增其他细菌）。检测到O157:H7的极高流行率为0.63（n = 401），其中阳性样本数量最多的省份是马纳比省，为72.8%（n = 225/309），皮钦查省为54.3%（n = 179/324）。在这两个省份，O157:H7污染的存在与小规模农场和气温升高呈正相关。本研究提供了关于生牛奶中存在的O157:H7微生物污染的宝贵数据，此外还提供了一种改进的方法，该方法已被证明比传统方法和先前发表的方法更快、更灵敏、更具特异性，突出了食源性感染的相关风险，并指出了农业实践监管中的潜在不足以及需要用更新的方法定期监测细菌污染水平。
