School of Food Science, Irrigated Agriculture Research and Experiment Center, Washington State University, Prosser, Washington 99350.
Department of Entomology and Plant Pathology.
J Food Prot. 2021 Jun 1;84(6):1009-1015. doi: 10.4315/JFP-20-339.
Flies are a vector for spreading foodborne pathogens pertinent to fresh produce, such as Shiga toxigenic Escherichia coli and Salmonella; however, most studies focus on concentrated animal feeding operations, which do not reflect low-density animal farming practices that often adjoin fruit and vegetable acreage. In this study, we determined the prevalence of Salmonella in flies collected biweekly on an integrated animal and produce operation over two growing seasons. Eleven of 889 pooled samples tested positive for Salmonella. Flies from the Calliphoridae, Muscidae, Sarcophagidae, and Tachinidae families were associated with Salmonella carriage, but fly family was not a significant factor for isolation of Salmonella (P = 0.303). Fly species were a significant factor (P = 0.026), with five Pentacricia aldrichii pools testing positive for Salmonella. With the exception of single specimen isolation, prevalence ranged from 2.2 to 15.2%. With the exception of the Tachinidae family, these results reflect a strong association of flies that are commonly associated with feces or are pests of animals. Trap location was not significantly associated with isolation of Salmonella-positive flies (P = 0.236). Overall, the population of flies was not as abundant as studies conducted with produce grown close to concentrated animal feeding operations, indicating a reduced risk of transmission; however, similar to these studies, fly families that are commonly isolated from fecal and decaying matter were most frequently associated with Salmonella isolation. Further work is warranted to elucidate the foodborne pathogen transmission rates to produce and subsequent survival over time.
蝇类是传播与新鲜农产品有关的食源性病原体的媒介，例如产志贺毒素大肠杆菌和沙门氏菌；然而，大多数研究都集中在集中式动物饲养操作上，而这些操作并不能反映通常与水果和蔬菜相邻的低密度动物养殖实践。在这项研究中，我们确定了在两个生长季节内，在一个集成的动物和农产品操作中每两周收集的苍蝇中沙门氏菌的流行率。在 889 个 pooled 样本中，有 11 个样本检测出沙门氏菌阳性。来自丽蝇科、蝇科、麻蝇科和寄蝇科的苍蝇与沙门氏菌携带有关，但苍蝇科并不是分离沙门氏菌的重要因素（P=0.303）。苍蝇种类是一个重要的因素（P=0.026），其中 5 个 Pentacricia aldrichii 池检测出沙门氏菌阳性。除了单个标本的分离外，流行率范围为 2.2%至 15.2%。除了寄蝇科外，这些结果反映了与粪便有关或为动物害虫的苍蝇的强烈关联。诱捕位置与分离沙门氏菌阳性苍蝇之间没有显著关联（P=0.236）。总体而言，苍蝇的数量并不像在靠近集中式动物饲养操作的地方种植的农产品中进行的研究那样丰富，这表明传播风险降低；然而，与这些研究类似，从粪便和腐烂物质中分离出的常见苍蝇科与沙门氏菌分离最常相关。需要进一步的工作来阐明食源性病原体向农产品的传播率以及随时间的后续生存能力。
