Hospital Environment-Associated Sources of Mycobacterium abscessus Infection in Transplant Recipients

Area of Science:

• Infectious Diseases
• Genomics
• Environmental Health

Background:

• Mycobacterium abscessus (MAB) causes severe infections in immunocompromised individuals, often in healthcare settings.
• Transmission routes and environmental reservoirs for MAB remain poorly understood, hindering infection control efforts.

Purpose of the Study:

• To identify the environmental sources and transmission pathways of MAB in healthcare settings.
• To determine the genetic relatedness of MAB isolates from patients and their environment using whole-genome sequencing.

Main Methods:

• Collected MAB isolates from patients and healthcare environments (tap water, sinks, etc.) in a tertiary care hospital.
• Utilized whole-genome sequencing to analyze genetic relatedness between patient and environmental isolates.
• Defined likely transmission based on single-nucleotide variation (SNV) differences.

Main Results:

• Identified 4 genomic clusters of MAB linking patient infections to specific hospital units.
• Tap water isolates were the only environmental samples genetically related to patient strains.
• MAB subspecies massiliense, part of a long-standing clone (DCC7), predominated in patient infections.

Conclusions:

• Tap water in patient care units is implicated as a likely source of MAB infections.
• Genomic analysis is crucial for understanding MAB acquisition in healthcare environments.
• Implementing robust water management protocols may prevent healthcare-associated MAB infections.