Modified cold Z-N staining for presumptive identification of Brucella.

Brucellosis is one of the most common zoonotic diseases in India. Growth of Brucella is slow and needs meticulous biochemical tests and antisera for confirmation of the isolates. In the present study modified cold ZN staining was tried on the broth cultures for early presumptive identification of Brucella growth. Blood cultures were attempted in 22 seropositive patients. In the five blood cultures positive for Brucella, acid-fast coccobacilli were seen in broth smears stained with modified cold ZN stain, thus providing presumptive identification of Brucella growth. Acid-fast bacteria were not seen in the broth smears of the remaining 17 broths negative for Brucella growth. The method is simple, reliable and reproducible and needs to be evaluated further on a larger sample.