Rhodococcus equi causes suppurative pneumonia in foals aged 1–3 months; moreover, it has emerged as a pathogenic cause of zoonotic diseases. After the initial report of the ruminant-pathogenic factor VapN encoded by the novel virulence plasmid pVAPN, several reports have described ruminant infections caused by vapN-harboring R. equi. Herein, we conducted a serological epidemiological surveillance in goats at a breeding farm (Farm A) and characterized the vapN-harboring R. equi isolates from this farm. First, we established a simple screening enzyme-linked immunosorbent assay (ELISA) using recombinant glutathione S-transferase–tagged VapN as an immobilized antigen. This method revealed that the VapN antibody titers were elevated in 12 of 42 goats. Subsequently, we attempted to isolate R. equi from the goat feces and soil of Farm A. choE⁺/vapN⁺ R. equi was isolated from the feces of Goat No. 27 and a soil sample near the shed. The pulsed-field gel electrophoresis (PFGE) patterns of five vapN-harboring R. equi strains isolated from Farm A in 2013 and 2019 were investigated and found to be the same except for the strain (OKI2019F1). However, no difference was observed in VapN expression and growth in macrophages among these vapN-harboring R. equi isolates. Our results revealed that some goats had histories of vapN-harboring R. equi infections, and two genomic types of vapN-harboring R. equi were found in isolates from Farm A. Ruminant-specific (pVAPN-carrying) R. equi might be an unrecognized pathogen in Japan and further studies are required to determine its prevalence and distribution.

马红球菌在1-3个月大的小马驹中引起化脓性肺炎。此外，它已成为人畜共患病的致病原因。在由新型毒力质粒pVAPN编码的反刍动物致病因子VapN的初步报道之后，一些报道描述了由携带vapN的R引起的反刍动物感染。当量。本文中，我们在一个繁殖场（农场A）对山羊进行了血清学流行病学监测，并确定了携带vapN的R的特征。当量从这个农场分离出来。首先，我们建立了一个简单的筛选酶联免疫吸附测定（ELISA），使用重组谷胱甘肽S-转移酶标记的VapN作为固定抗原。该方法显示，在42只山羊中的12只中，VapN抗体滴度升高。随后，我们试图分离[R 。球菌从农场A的山羊粪便和土壤崔⁺ / vapN ⁺ - [R 。球菌是从山羊第27号的粪便和梭口附近的土壤样品中分离出来。五个携带vapN的R的脉冲场凝胶电泳（PFGE）模式。当量2013年和2019年从农场A分离的菌株进行了调查，发现除菌株（OKI2019F1）相同。然而，在这些携带vapN的R中，没有观察到VapN表达和巨噬细胞生长的差异。马分离物。我们的结果表明，有些山羊具有vapN携带R的历史。球菌感染，和两个基因组类型的vapN -harboring ř。球菌在从农场A.反刍动物特异性分离物中发现（pVAPN承载）马红球菌 可能是日本无法识别的病原体，需要进一步研究以确定其流行程度和分布。