Molecular detection of Brucella species among aborted small ruminants in southeast Iran.

Brucellosis, caused by Brucella bacteria, is a common zoonotic infectious disease with various clinical manifestations in humans and animals. The disease is endemic in human and ruminant populations in Iran, with a particular prevalence in areas where humans have close interactions with livestock. Since domestic animals serve as the primary reservoir for brucellosis, this study aimed to identify the presence of Brucella spp. among aborted small ruminants in southeast Iran. Between 2021 and 2022, aborted fetuses of small ruminants (46 sheep and 4 goats) were collected from Zarand County in the Kerman province. Swab samples from the abomasum contents of these fetuses were obtained and subjected to DNA extraction. The samples were then tested for Brucella spp. detection using the polymerase chain reaction (PCR) method. Out of the 50 aborted fetuses examined, Brucella spp. was detected in 15 (30%) specimens, comprising 13 (28%) sheep and 2 (50%) goats. Species typing revealed the presence of Brucella ovis (6 sheep and 1 goat), Brucella melitensis (6 sheep), and Brucella abortus (1 sheep) among the positive specimens. This cross-sectional study highlights the high prevalence of various Brucella species in samples from small ruminant abortions in southeast Iran. Additionally, the identified Brucella species were not limited to their primary host livestock. These indicated potential cross-species transmission among small ruminants.