Mycobacteria in water, soil, plants and air: a review

Abstract

Amazingly, despite the 24 143 papers on mycobacteria, indexed in the Web of Science database during the last six years, published by 67 008 authors from 13 128 organizations located in 166 countries or territories, internationally accepted legal directives on how to control the public health risk associated with environmental mycobacteria have yet to be developed. Mycobacteria are human and animal pathogens, causing not only tuberculosis and leprosy, but mycobacterioses of skin, soft tissues and lung. Due to their cell wall composition and their adaptability mycobacteria can survive in different habitats for years. Their immunomodulatory ability has been recognised for more than 50 years and hundreds of papers published during the last two decades have demonstrated that small chemical products derived from mycobacterial cells participate in inflammatory pathways involved the pathogenesis of important human diseases like Crohn’s disease, asthma, type 1 diabetes mellitus, psoriasis, arthrosis, Blau syndrom, sarcoidosis, autism etc. Mycobacteria can influence inflammatory pathways not only as live organisms, but also by means of components derived from dead cells. Pasteurisation or cooking does not affect this ability. Hence, how many mycobacterial cells are ingested, what factors play a role concurrently, and how long the harmful effect persists become important questions. This paper presents only a short review based on selected papers about mycobacteria in water, soil, plants and air with the aim of attracting attention to this significant global problem and of making the first steps towards protection of people. Selected bibliographic references of published data from 2007 to 2012 are presented in easy-to-navigate tables.