Mycobacterium avium subsp. hominissuis (MAH) is one of the most common nontuberculous mycobacterial pathogens responsible for chronic lung disease in humans. It is widely distributed in biofilms in natural and living environments. It is considered to be transmitted from the environment. Despite its importance in public health, the ultrastructure of the MAH biofilm remains largely unknown. The ultrastructure of a MAH-containing multispecies biofilm that formed naturally in a bathtub inlet was herein reported along with those of monoculture biofilms developed from microcolonies and pellicles formed in the laboratory. Scanning electron microscopy revealed an essentially multilayered bathtub biofilm that was packed with cocci and short and long rods connected by an extracellular matrix (ECM). Scattered mycobacterium-like rod-shaped cells were observed around biofilm chunks. The MAH monoculture biofilms that developed from microcolonies in vitro exhibited an assembly of flat layers covered with thin film-like ECM membranes. Numerous small bacterial cells (0.76±0.19 μm in length) were observed, but not embedded in ECM. A glycopeptidolipid-deficient strain did not develop the layered ECM membrane architecture, suggesting its essential role in the development of biofilms. The pellicle biofilm also consisted of flat layered cells covered with an ECM membrane and small cells. MAH alone generated a flat layered biofilm covered with an ECM membrane. This unique structure may be suitable for resistance to water flow and disinfectants and the exclusion of fast-growing competitors, and small cells in biofilms may contribute to the formation and transmission of bioaerosols.

中文翻译：

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鸟分枝杆菌亚种的超微结构。Hominissuis生物膜。

鸟分枝杆菌亚种 人型沙门氏菌（MAH）是导致人类慢性肺部疾病的最常见的非结核性分枝杆菌病原体之一。它在自然和生活环境中广泛分布在生物膜中。它被认为是从环境传播的。尽管它在公共卫生中具有重要意义，但MAH生物膜的超微结构仍是未知之数。本文报道了在浴缸入口自然形成的含MAH的多物种生物膜的超微结构，以及从实验室中形成的微菌落和防护膜发展而来的单培养生物膜的超微结构。扫描电子显微镜揭示了基本上多层的浴缸生物膜，其中充满了球菌和通过细胞外基质（ECM）连接的长杆和短杆。在生物膜块周围观察到散乱的分枝杆菌样杆状细胞。从体外菌落形成的MAH单培养生物膜显示出覆盖有类似薄膜的ECM膜的平坦层的组件。观察到许多小细菌细胞（长度为0.76±0.19μm），但未嵌入ECM中。糖肽脂质缺陷型菌株未形成分层的ECM膜结构，表明其在生物膜形成中的重要作用。防护膜生物膜还由覆盖有ECM膜的平层细胞和小细胞组成。单独的MAH产生了覆盖有ECM膜的平坦生物膜。这种独特的结构可能适合抵抗水流和消毒剂，并排除快速增长的竞争对手，