Naseem Muhammad Noman, Allavena Rachel, Raza Ali, Constantinoiu Constantin, McGowan Michael, Turni Conny, Kamran Muhammad, Tabor Ala E, James Peter
The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Centre for Animal Science, St. Lucia, QLD, Australia.
School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.
Front Vet Sci. 2023 Jan 18;9:971813. doi: 10.3389/fvets.2022.971813. eCollection 2022.
, commonly known as buffalo fly, is the major hematophagous ectoparasite of north Australian cattle herds. Lesions associated with buffalo fly infestation are generally alopecic, hyperkeratotic, or scab encrusted wounds with variable hemorrhagic ulceration. Buffalo flies can transmit a filarial nematode, sp., which has been implicated in the pathogenesis of buffalo fly lesions, but infection has not been detected in all lesions suggesting that other causal factors may be involved. This study characterized the pathology of buffalo fly lesions to identify the role of in lesion development, as well as to identify other potential agents. Lesion biopsies were collected from north and south Queensland and tested for the presence of by qPCR. Each lesion was scored grossly (0-4) for hemorrhage, ulceration, exudation, and alopecia. Lesions were also scored microscopically (0-4) for epidermal and dermal damage and inflammatory characters. infection was detected in 31% of lesion biopsies. Grossly, -infected lesions had significantly larger lesion area and higher scores for alopecia and hyperkeratosis than lesions where no nematodes were found ( < 0.05). Histologically, epidermal, dermal, and adnexal damage was significantly higher in infected lesions than lesions without nematodes. Eosinophils, macrophages, and lymphocytes were significantly more abundant in positive lesions as compared to negative lesions. This study also noted bacterial infection with colonies of coccoid bacteria, observed in skin sections from 19 lesions. Grossly, lesions with bacterial infection had significantly higher ulceration scores compared to positive lesions, and histologically epidermal disruption was significantly greater in bacteria-infected lesions. We found no evidence of bacteria or infection in 49% of the lesions assessed and tissue damage patterns and eosinophilic inflammation suggested hypersensitivity to buffalo fly feeding as a possible cause of these lesions. These findings suggest that although the presence of infection may increase the severity of lesion pathology, it is not essential for lesion development. These outcomes also suggest a potential role of bacteria and hypersensitivity in pathogenesis of some lesion. A better understanding of buffalo fly lesion etiology will contribute to the optimal treatment and control programmes.
，通常被称为水牛蝇，是澳大利亚北部牛群的主要吸血外寄生虫。与水牛蝇感染相关的病变通常是脱毛性、角化过度性或结痂性伤口，并伴有不同程度的出血性溃疡。水牛蝇可传播一种丝虫线虫，即 种，它与水牛蝇病变的发病机制有关，但并非在所有病变中都检测到该线虫感染，这表明可能涉及其他致病因素。本研究对水牛蝇病变的病理学特征进行了分析，以确定该线虫在病变发展中的作用，同时识别其他潜在病原体。从昆士兰州北部和南部采集病变活检组织，通过定量聚合酶链反应（qPCR）检测是否存在该线虫。对每个病变的出血、溃疡、渗出和脱毛情况进行大体评分（0 - 4分）。病变还在显微镜下对表皮和真皮损伤以及炎症特征进行评分（0 - 4分）。在31%的病变活检组织中检测到该线虫感染。大体上，感染该线虫的病变比未发现线虫的病变具有显著更大的病变面积，且脱毛和角化过度评分更高（P < 0.05）。组织学上，感染该线虫的病变中表皮、真皮和附属器损伤明显高于未感染线虫的病变。与阴性病变相比，该线虫阳性病变中的嗜酸性粒细胞、巨噬细胞和淋巴细胞明显更为丰富。本研究还注意到在19个病变的皮肤切片中观察到球状细菌菌落的细菌感染。大体上与该线虫阳性病变相比，有细菌感染的病变溃疡评分显著更高，且组织学上细菌感染的病变中表皮破坏明显更大。在评估的49%的病变中，我们未发现细菌或该线虫感染的证据，组织损伤模式和嗜酸性炎症表明对水牛蝇叮咬过敏可能是这些病变的一个原因。这些发现表明，虽然该线虫感染的存在可能会增加病变病理学的严重程度，但它对于病变发展并非必不可少。这些结果还表明细菌和过敏在某些病变的发病机制中可能发挥作用。更好地了解水牛蝇病变病因将有助于制定最佳的治疗和控制方案。
