Characterization of Brucella spp., and other abortigenic pathogens from
aborted tissues of cattle and goats in Rwanda
Abstract
This study aimed to characterize Brucella spp., and other
abortigenic pathogens from aborted tissues of cattle from five selected
districts of Rwanda. For cattle, aborted tissues (n=19) were collected,
cultured, and Brucella spp. were detected using genus-specific
16S-23S ribosomal DNA interspacer region (ITS) assay and further
speciated using AMOS and Bruce-ladder PCR assays. Brucella
negative samples were screened using eight abortion pathogens PCR panel
( Anaplasma phagocytophilum, Bovine Herpesvirus 4,
Campylobacter fetus, Chlamydophila spp., Coxiella
burnetti, Leptospira spp., Listeria monocytogenes, and
Salmonella spp.). samples from an abortion outbreak that occurred
within a goat tribe in the Nyagatare district were included in this
investigation. Sera of females (n=8), and males (n=2) were analysed
using the Rose Bengal Test (RBT), and indirect enzyme-linked
immunosorbent assay (i-ELISA), while vaginal swabs (n=3), and aborted
tissues (n=1) were cultured and characterized. The ITS-PCR detected
Brucella DNA in cultures from two aborted tissues of cattle
[10.5%, (2/19)] which were identified as B. melitensis
(n=1), and B. abortus (n=1) using AMOS and Bruce-ladder PCR
assays. Campylobacter fetus (n=7) and Leptospira spp.
(n=4) including co-infections (n=2) of C. fetus and
Leptospira spp. were identified with the PCR panel from the
Brucella negative samples of cattle. Goats (100.0%, 10/10) were
brucellosis seropositive on RBT and i-ELISA. Mixed infections caused by
B. melitensis and B. abortus were isolated from the
vaginal swabs (n=3) and aborted tissues (n=1). The isolation of both
B. abortus and B. melitensis indicated cross-infections
and mixed livestock farming in Rwanda. This is the first identification
of abortion-associated pathogens ( B. abortus, B.
melitensis, C. fetus, and Leptospira spp.) in aborted
cattle samples in Rwanda indicating the enormous financial losses to
cattle owners and a threat to public health. It is therefore essential
to include these identified pathogens in the surveillance scheme of
veterinary and human services, and raise the awareness of caretakers,
abattoir workers, and laboratory personnel.