The European wild boar (WB) (Sus scrofa) population has rapidly expanded over the years, raising public health concerns over the species reservoir of several pathogens, including Mycobacterium microti (Mm), a Mycobacterium tuberculosis complex member. In this study, we aimed to investigate the Mm natural infection in WB in Lombardy and Emilia Romagna Italian regions by statistically evaluating the granulomatous lesions' histological features and Mm microbiological isolation. We analyzed 103 WB retropharyngeal and submandibular lymph nodes (LNs) for Mm identified by gyrB PCR-restriction fragment length polymorphism, and were retrospectively selected and histologically assessed. For each sample, Hematoxylin-eosin and Ziehl–Neelsen stained slides were evaluated. Considered histological variables were: the number of granulomas, size and maturational stage of granulomas, granulomas completeness within the section, number of multinucleated giant macrophages (MGMs), and acid-fast (AF) bacilli per granuloma. Furthermore, Mm microbiological results were also considered. Mm microbiological isolation was negatively influenced by granulomas maturation and positively affected by AF bacilli's presence within the section. Granuloma maturation was positively influenced by granuloma size and granuloma incompleteness and negatively affected by the number of granulomas in the section and the number of MGMs within the granuloma. The results indicate that granuloma maturation should ensures an efficient containment of Mm infection in the WB, suggesting that the intra-species transmission of the disease might be an unlikely event.

欧洲野猪 (WB) (野猪) 人口多年来迅速扩大，引起了公众对几种病原体物种储存库的关注，包括 微小分枝杆菌 (毫米）， 一种 结核分枝杆菌复杂的成员。在这项研究中，我们旨在调查毫米 通过统计评估肉芽肿病灶的组织学特征和 毫米微生物隔离。我们分析了 103 个 WB 咽后和下颌下淋巴结 (LN)毫米 由 gyrBPCR 限制性片段长度多态性，并进行回顾性选择和组织学评估。对于每个样品，对苏木精-伊红和 Ziehl-Neelsen 染色的载玻片进行评估。考虑的组织学变量是：肉芽肿的数量、肉芽肿的大小和成熟阶段、切片内的肉芽肿完整性、多核巨噬细胞 (MGM) 的数量和每个肉芽肿的抗酸 (AF) 杆菌。此外，毫米 还考虑了微生物结果。 毫米微生物分离受到肉芽肿成熟的负面影响，并受到切片内 AF 杆菌的积极影响。肉芽肿的成熟受到肉芽肿大小和肉芽肿不完整的积极影响，并受到切片中肉芽肿数量和肉芽肿内 MGM 数量的负面影响。结果表明，肉芽肿成熟应确保有效遏制毫米 WB 中的感染，表明该疾病的种内传播可能是不太可能发生的事件。