Abstract:
In livestock, brucellosis is mainly an asymptomatic disease except when abortion occurs; therefore, two serological tests are used for diagnosis as no single test is suitable. Abattoir samples enable a combination of culture, molecular, and serological tests to detect brucellosis. This study assessed Brucella-specific PCR (ITS-PCR) to detect brucellosis and to conduct a molecular characterization of Brucella spp. isolated from PCR-positive livestock (n = 565) slaughtered at abattoirs and the appropriate sample tissue(s). ITS-PCR detected Brucella DNA in 33.6% of cattle, 14.5% of sheep, and 4.7% of pig tissues. Impure Brucella cultures from PCR-positive tissues were 43.6% (44/94) of cattle, 51.7% (15/29) of sheep, and 50% (2/4) of pigs with predominantly B. abortus identification with AMOS-PCR and low isolation of mixed B. abortus and B. melitensis in all species. In cattle, 33% of isolates were from lymph nodes, while in sheep 38.0% were from the liver and kidney and only from tonsils in pigs (2/4). Brucella infections identified with AMOS-PCR were present in seropositive and mainly seronegative (75.6–100%) livestock with the potential to cause brucellosis during pregnancy or breeding. This study demonstrated the value of the polyphasic approach, especially with chronic infections and the potential risk of these asymptomatic animals.
Description:
SUPPLEMENTARY MATERIAL : TABLE S1: Molecular and serological identification of
Brucella spp. in livestock.; FIGURE S1: Gel electrophoresis of Bruce-Ladder PCR amplification to
differentiate the field strains from vaccine strains. Lanes 1–5 and 10 show amplification of B. abortus,
lanes 6–8 show amplification of B. melitensis, lane 9 show Rev 1 positive and lane 11 and 12 show
negative controls.
DATA AVAILABILITY STATEMENT : All the relevant data and supplementary information are contained
within the paper.
