Background:

Bacteria of the genus Brucella yield the disease known as brucellosis (the most critical zoonosis in the world). Currently, 14 species are recognized, reported in marine mammals, amphibians, and commercial fish. In recent years, in the Eastern Basin, Brucella melitensis was detected in agricultural soil and the Crater Lakes’ water, so it was speculated whether B. melitensis could infect native ichthyofauna.

Objective:

Isolate and identify Brucella melitensis in the charal of La Preciosa Crater Lake (Poblana letholepis).

Methods:

The first isolation was carried out on agar-plate from soft tissues and identifying the microorganism through standard microbiological tests. Which was corroborated by PCR-PF, using reference strains, by amplifying the bp26 gene, specific for the genus Brucella.

Results:

B. melitensis was isolated in 66.66% of the samples studied n=60, the microbiological profiles were comparatively identical with the reference strains. The PCR test amplified the genus-specific gene bp26 with 1029 bp in 40% of the samples analyzed.

Conclusions:

The study generated the first isolation and identification report for Brucella melitensis in a native fish, which supports future studies to better understand this zoonotic disease and recognize the importance of native fauna in the transmission and permanence of brucellosis in natural aquatic environments.