A three-year project by NCCOS scientists has culminated in a reliable tool for rapid detection of pathogenic Brucella bacteria in clinical samples from marine mammals. Rapid detection of these pathogens in marine mammals has been difficult ever since Brucella infections were first recognized in marine mammals in the 1990s. Brucellosis, a Brucella-based reproductive disease, is prevalent in marine mammals and may have great impact on population dynamics, particularly among populations with low growth rates, such as dolphins. Marine mammal Brucella can also infect humans. Microbiologic culture is used for definitive diagnosis of brucellosis, but is time consuming, has low sensitivity, and can be hazardous to laboratory personnel.

Fetal and neonatal marine mammals may have the greatest susceptibility to Brucella ST27 infection, a strain that can also infect humans who come in contact with infected animals.

NCCOS, in collaboration with the University of California -Davis and the Centers for Disease Control, developed a real-time polymerase chain reaction (PCR) assay for rapid detection of Brucella and Brucella ST27, a genotype associated with human zoonotic infection. The assay was found to be 100 percent sensitive for the Brucella strains tested. Also, testing results indicate that fetal and neonatal animals may have the greatest susceptibility to ST27 infections. This is the first report on the use of a real-time PCR assay for identification of Brucella ST27 in marine mammals.

This research was recently published in the Journal of Microbiological Methods.