Two bottlenose dolphins (Tursiops truncatus) aborted fetuses that died as a
result of Brucella infection. Brucella placentitis occurred in both cases.
Infected placenta and vaginal/uterine fluids may transmit Brucella species
to other cetaceans. In a third case, an identical organism was cultured fr
om lung necropsy tissue of an adult female T. truncatus. Microbiology, spec
ific polymerase chain reaction, and pulsed-field gel electrophoresis result
s supported the designation of an additional genomic group(s), Brucella del
phini, for isolates adapted to T. truncatus. Current serologic diagnostic t
ests reliable for known Brucella species are unreliable in detecting dolphi
n brucellosis. Our findings, together with previous reports, suggest that d
olphin brucellosis is a naturally occurring disease that can adversely impa
ct reproduction in cetaceans. The zoonotic significance of cetncean brucell
osis is unknown, although the disease has not been reported in people who h
ave frequent contact with dolphins. Further studies. on the zoonotic aspect
s, distribution, prevalence, virulence, and impact of this disease in cetac
eans and other marine mammal species are needed.