Bovine anaplasmosis, caused by Anaplasma marginale, is widespread in cattle in the southeast United States. The pathogen is biologically transmitted by Dermacentor spp. ticks, and mechanically transmitted by biting flies and via fomites. Despite high reported regional seroprevalence, Dermacentor spp. are rare on cattle in the southeast. To identify other putative An. marginale vectors, and to characterize cattle exposure to other tick-borne pathogens, we collected ticks from Arkansas cattle herds in 2020–2022. Recognizing that deer are important hosts for some of the same tick species that parasitize cattle, we also collected ticks from hunter-killed deer in the fall and winter of 2021. Ticks were screened for bacteria in the family Anaplasmataceae using qPCR. Positive samples were further amplified using a PCR assay targeting the groEL gene, and the resulting amplicons were sequenced for identification. A total of 3,794 ticks were collected, the majority of which were Amblyomma americanum. Amblyomma americanum was the most common species on cattle, and Ixodes scapularis was most common on deer. No ticks were positive for An. marginale, though Anaplasma phagocytophilum was detected in deer-collected I. scapularis, as well as in a single engorged Am. americanum from cattle. Amblyomma americanum from cattle were infected with Ehrlichia ewingii, Ehrilichia chaffeensis, and Panola Mountain Ehrlichia. Cattle in Arkansas are exposed to several ehrlichial pathogens and may also be exposed to An. phagocytophilum. The importance of these pathogens, particularly Panola Mountain Ehrlichia, in causing cattle disease in Arkansas deserves further study, as does the importance of mechanical transmission of An. marginale in bovine anaplasmosis epidemiology.

由边缘无形体引起的牛无形体病在美国东南部的牛中广泛存在。该病原体通过皮肤病菌 ( Dermacentor spp) 进行生物传播。蜱虫，并通过叮咬苍蝇和污染物机械传播。尽管报告的区域血清流行率很高，但Dermacentor spp. 在东南部的牛中很少见。识别其他假定的An。为了描述牛与其他蜱传病原体的接触情况，我们在 2020-2022 年从阿肯色州牛群中收集了蜱。认识到鹿是某些寄生于牛的相同蜱种的重要宿主，我们还在 2021 年秋季和冬季从被猎人杀死的鹿身上收集了蜱。使用 qPCR 对蜱进行了无形体科细菌的筛查。使用针对 groEL 基因的 PCR 检测进一步扩增阳性样本，并对所得扩增子进行测序以进行鉴定。总共收集了 3,794 只蜱，其中大部分是美洲钝蜱 (Amblyomma americanum)。美洲钝蜱（Amblyomma americanum）是牛身上最常见的物种，肩胛硬蜱（Ixodes scapularis）是鹿身上最常见的物种。An没有蜱呈阳性。边缘，尽管在鹿采集的I. scapularis以及单个充血的 Am 中检测到了嗜吞噬细胞无形体。来自牛的美国。来自牛的Amblyomma americanum感染了尤因埃里希体、恰菲埃里希体和帕诺拉山埃里希体。阿肯色州的牛暴露于多种埃立克体病原体，也可能接触埃利希体病原体。嗜吞噬细胞。这些病原体，特别是帕诺拉山埃里希体，在阿肯色州引起牛病方面的重要性值得进一步研究，埃利希体机械传播的重要性也值得进一步研究。牛无形体病流行病学的边缘。