Zoonotic Nontuberculous Mycobacteria: Transmission Pathways, Laboratory Diagnosis, Detection Methodologies, and One Health Priorities.

Nontuberculous mycobacteria (NTM) are an ecologically diverse group of environmental mycobacteria that are increasingly recognized as an important cause of human and animal disease. While most infections arise from environmental exposure, evidence from outbreak reports and genomic epidemiology suggests animal- associated and device-associated transmission pathways that intersect with human occupational and clinical risk. This review synthesizes current knowledge on zoonotic and animal-associated NTM, including recent taxonomy updates driven by genomic approaches, major reservoirs (including aquaculture, livestock, wildlife, and engineered water systems), as well as clinical and veterinary manifestations, and operational laboratory approaches for detection and characterization. We present a tiered diagnostic framework, ranging from microscopy and culture to targeted polymerase chain reaction (PCR), whole-genome sequencing, and emerging metagenomic and artificial intelligence (AI)-based pipelines, and we discuss biosafety considerations, reporting standards, and One Health surveillance priorities. Key research gaps include distinguishing true animal-to-human transmission from shared-source exposure, harmonizing One Health metadata and antimicrobial resistance (AMR) surveillance, and validating climate-sensitive predictive models. We propose practical, resource-adaptive recommendations for surveillance, laboratory workflows, and outbreak response. A coordinated global investment in integrated One Health genomic surveillance, harmonized metadata standards, and capacity building is urgently required to detect, attribute, and mitigate zoonotic NTM threats.