IDENTIFICATION OF Brucella abortus FROM ARTISANAL-FRESH COW-MILK CHEESE IN VERACRUZ, MEXICO

Abstract

Brucellosis is a zoonosis whose main source of infection is contaminated milk and unpasteurized products. The difficulty of isolating the agent limits the definitive diagnosis, so the joint use of methods such as the polymerase chain reaction (PCR) and the inoculation of susceptible animals may represent an alternative to isolate and identify Brucella spp. The objective was to identify the presence of Brucella abortus from samples of artisanal fresh cow milk cheese collected in five collection centers in the central area of the Mexican state of Veracruz using a murine infection model and PCR. The design of the study was cross-sectional epidemiological and 100 samples of cheese were collected during May and June of 2017 that were analyzed by conventional microbiology. In one sample, the presence of a S19 vaccine strain of B. abortus was identified by multiplex PCR. To try their isolation, from said sample of cheese, ten mice were inoculated intraperitoneally according to the provisions of NOM-062-ZOO-1999. The female mice were sacrificed by cervical dislocation, samples of liver, kidney, spleen and bone marrow were extracted and plated with Agar-Farell plates, which were maintained in aerobiosis for 10 d. None of the female mice were seroconverted nor colonies of Brucella spp. developed from extracted organs, but PCR diagnosis was useful to identify Brucella spp. in fresh cheeses.