Milk Contamination by Mycobacterium tuberculosis Complex, Implications for Public Health in Amazonas, Brazil

Area of Science:

• Foodborne pathogens
• Microbiology
• Public Health

Background:

• Raw milk consumption is high in Amazonas, Brazil, a region with elevated tuberculosis prevalence in humans and livestock.
• Mycobacterium tuberculosis complex (MTC) contamination in raw milk has been previously reported in Brazil.

Purpose of the Study:

• To assess MTC contamination in cow and buffalo raw milk in Amazonas, Brazil.
• To identify the prevalence of Mycobacterium bovis in raw milk samples.

Main Methods:

• Collected 250 raw milk samples (91 cow, 159 buffalo) from three milk plants in Amazonas.
• Utilized shotgun metagenomic sequencing (Kraken 2, MegaBLAST) and BLASTN for MTC identification.
• Analyzed milk samples pooled into 21 groups.

Main Results:

• MTC genetic material was detected in all raw milk pools.
• Mycobacterium bovis genetic material was found in 7 pools (1 cow, 6 buffalo).
• Buffalo milk exhibited significantly higher MTC reads compared to cow milk.

Conclusions:

• Raw milk consumption in Amazonas poses a significant public health risk for foodborne tuberculosis transmission.
• Urgent public health measures are required to prevent MTC transmission via food.
• Elimination of bovine tuberculosis in cattle and buffalo herds in Brazil is essential.