Nishiuchi Yukiko, Iwamoto Tomotada, Maruyama Fumito
Toneyama Institute for Tuberculosis Research, Osaka City University Medical School , Toyonaka , Japan.
Department of Infectious Diseases, Kobe Institute of Health , Kobe , Japan.
Front Med (Lausanne). 2017 Mar 7;4:27. doi: 10.3389/fmed.2017.00027. eCollection 2017.
Numerous studies have revealed a continuous increase in the worldwide incidence and prevalence of non-tuberculous mycobacteria (NTM) diseases, especially pulmonary complex (MAC) diseases. Although it is not clear why NTM diseases have been increasing, one possibility is an increase of mycobacterial infection sources in the environment. Thus, in this review, we focused on the infection sources of pathogenic NTM, especially MAC. The environmental niches for MAC include water, soil, and dust. The formation of aerosols containing NTM arising from shower water, soil, and pool water implies that these niches can be infection sources. Furthermore, genotyping has shown that clinical isolates are identical to environmental ones from household tap water, bathrooms, potting soil, and garden soil. Therefore, to prevent and treat MAC diseases, it is essential to identify the infection sources for these organisms, because patients with these diseases often suffer from reinfections and recurrent infections with them. In the environmental sources, MAC and other NTM organisms can form biofilms, survive within amoebae, and exist in a free-living state. Mycobacterial communities are also likely to occur in these infection sources in households. Water distribution systems are a transmission route from natural water reservoirs to household tap water. Other infection sources include areas with frequent human contact, such as soil and bathrooms, indicating that individuals may carry NTM organisms that concomitantly attach to their household belongings. To explore the mechanisms associated with the global spread of infection and MAC transmission routes, an epidemiological population-wide genotyping survey would be very useful. A good example of the power of genotyping comes from subsp. , where close genetic relatedness was found between isolates of it from European patients and pigs in Japan and Europe, implying global transmission of this bacterium. It is anticipated that whole genome sequencing technologies will improve NTM surveys so that the mechanisms for the global spread of MAC disease will become clearer in the near future. Better understanding of the niches exploited by MAC and its ecology is essential for preventing MAC infections and developing new methods for its effective treatment and elimination.
众多研究表明，全球非结核分枝杆菌（NTM）疾病的发病率和患病率持续上升，尤其是肺部复合症（MAC）疾病。尽管尚不清楚NTM疾病为何呈上升趋势，但一种可能性是环境中分枝杆菌感染源的增加。因此，在本综述中，我们重点关注致病性NTM的感染源，尤其是MAC。MAC的环境生态位包括水、土壤和灰尘。淋浴水、土壤和泳池水中产生的含有NTM的气溶胶的形成意味着这些生态位可能是感染源。此外，基因分型显示临床分离株与来自家庭自来水、浴室、盆栽土和花园土壤的环境分离株相同。因此，为了预防和治疗MAC疾病，识别这些病原体的感染源至关重要，因为患有这些疾病的患者经常遭受再次感染和反复感染。在环境源中，MAC和其他NTM生物体可以形成生物膜，在变形虫内生存，并以自由生活状态存在。分枝杆菌群落也可能在家庭中的这些感染源中出现。供水系统是从天然水库到家庭自来水的传播途径。其他感染源包括人类频繁接触的区域，如土壤和浴室，这表明个体可能携带NTM生物体，这些生物体同时附着在他们的家庭物品上。为了探索与感染全球传播和MAC传播途径相关的机制，一项全人群的基因分型流行病学调查将非常有用。基因分型作用的一个很好例子来自亚种，在那里发现来自欧洲患者的分离株与日本和欧洲的猪的分离株之间存在密切的遗传相关性，这意味着这种细菌的全球传播。预计全基因组测序技术将改善NTM调查，以便在不久的将来MAC疾病全球传播的机制将变得更加清晰。更好地了解MAC利用的生态位及其生态学对于预防MAC感染以及开发有效的治疗和消除新方法至关重要。
