Non-Tuberculous Mycobacteria at the Human-Animal-Environment Interface: Antimicrobial Resistance, Environmental...

Area of Science:

• Environmental microbiology
• One Health
• Antimicrobial Resistance (AMR)

Background:

• Non-tuberculous mycobacteria (NTM) are emerging opportunistic pathogens at the human-animal-environment interface.
• Their significance is growing due to increased disease, environmental persistence, diverse animal hosts, and complex AMR patterns.
• NTM are primarily acquired from environmental reservoirs, unlike typical zoonotic pathogens.

Purpose of the Study:

• To review NTM from a One Health perspective, focusing on AMR, ecology, animal occurrence, cross-species exposure, and public health relevance.
• To synthesize evidence on NTM ecology, environmental reservoirs, animal occurrence, transmission, and AMR mechanisms.
• To highlight implications for One Health surveillance and risk assessment at the human-animal-environment interface.

Main Methods:

• A narrative literature review was conducted.
• Evidence synthesis focused on NTM ecology, environmental reservoirs, animal occurrence, transmission patterns, and AMR mechanisms.
• Particular attention was paid to the human-animal-environment interface and One Health implications.

Main Results:

• NTM are widespread in water, soil, sediments, and biofilms, offering repeated exposure opportunities for animals and humans.
• Reported in livestock, wildlife, companion animals, reptiles, and aquatic organisms, acting as colonizers or pathogens.
• Limited direct animal-to-human transmission evidence; however, animal and environmental data are key for understanding circulation of resistant strains.
• AMR in NTM is influenced by intrinsic resistance, mutations, efflux, and biofilm tolerance, complicating treatment and prediction.

Conclusions:

• NTM are environmentally maintained, multi-host organisms of increasing One Health importance, not conventional zoonotic pathogens.
• Enhanced interdisciplinary surveillance, diagnostics, and research are essential.
• Clarifying exposure pathways, resistance development, and public health risks is critical.