Here we report an outbreak of an atypical, ulcerative dermatitis in North Country mule lambs, located in South Gloucestershire, UK. The lesions, which appeared to be contagious, occured between the coronary band and the carpal joint as a focal, well demarcated, circular, ulcerative dermatitis. Histopathological examination of the lesion biopsies revealed areas of ulceration, epidermal hyperplasia, suppurative dermatitis and granulation tissue. Clumped keratohyalin granules and intracellular keratinocyte oedema (ballooning degeneration) were evident within lesion biopsies, consistent with an underlying viral aetiology. A PCR-based microbiological investigation failed to detect bovine digital dermatitis-associated treponeme phylogroups, Dichelobacter nodosus, Staphylococcus aureus, Dermatophilus congolensis or Chordopoxvirinae virus DNA. However, 3 of the 10 (30 %) and 6 of 10 (60 %) lesion samples were positive for Fusobacterium necrophorum and Streptococcus dysgalactiae DNA, respectively. Contralateral limb swabs were negative by all standard PCR assays. To better define the involvement of F. necrophorum in the aetiology of these lesions, a qPCR targeting the rpoB gene was employed and confirmed the presence of F. necrophorum DNA in both the control and lesions swab samples, although the mean F. necrophorum genome copy number detected in the lesion swab samples was ∼19-fold higher than detected in the contralateral control swab samples (245 versus 4752 genome copies/μl, respectively; P < 0.001). Although we have not been able to conclusively define an aetiological agent, the presence of both F. necrophorum and S. dysgalactiae in the majority of lesions assayed supports their role in the aetiopathogenesis of these lesions.

在这里，我们报告了位于英国南格洛斯特郡的北部乡村m子羔羊爆发的一种非典型溃疡性皮炎。病变似乎具有传染性，发生在冠状动脉带和腕关节之间，为局灶性，界限分明的圆形溃疡性皮炎。病变活检的组织病理学检查显示有溃疡，表皮增生，化脓性皮炎和肉芽组织。在病灶活检中明显见到结节性角蛋白透明颗粒和细胞内角质形成细胞水肿（气球状变性），与潜在的病毒病因相一致。基于PCR的微生物学研究未能检测到牛数字性皮炎相关的treponeme系统群，结节双歧杆菌，金黄色葡萄球菌，congolensis或Chordopoxvirinae病毒DNA。但是，10个病灶样品中的3个（30％）和10个病灶样品中的6个（60％）对坏死镰刀菌和dysgalococcus dysgalactiae DNA呈阳性。通过所有标准PCR测定，对侧肢拭子均为阴性。为了更好地确定坏死镰刀菌在这些病因中的作用，采用了针对rpoB基因的qPCR，并确认了对照和病灶拭子样品中都有坏死镰刀菌DNA，尽管平均坏死镰刀菌病变拭子样品中检测到的基因组拷贝数比对侧对照拭子样品中检测到的基因组拷贝数高约19倍（分别为245对4752个基因组拷贝/μl； P <0.001）。尽管我们还不能最终确定病因，但在大多数被分析的病灶中，坏死镰刀菌和dysgalactiae的存在都支持它们在这些病因中的作用。