ABSTRACT
Vertical transmission of Brucella abortus in Sprague-Dawley (SD) rats was verified with microbiologic, serologic, and polymerase chain reaction (PCR) methods. The 38 initially Brucella-free SD rats, weighing 200 to 250 g, were injected subcutaneously with 50 microL of a suspension containing 1 x 10(9) colony-forming units (cfu) of B. abortus biotype 1 Korean isolate. The rats were allowed to mate with uninfected SD rats. The isolate was detected by culture and by AMOS (abortus, melitensis, ovis, suis) PCR in testis tissue of infected male rats and splenic tissue of infected female rats. By 7 d after inoculation, the results of both the rose bengal test (RBT) and the plate agglutination test (PAT) were positive for antibody against B. abortus; the reciprocal antibody titre ranged from 200 to 400 in the 1-mo-old offspring and 800 in their dams. The infected rats directly transmitted Brucella to their breeding partners and offspring. Fetuses of infected dams were found to be infected at 20 d of gestation. These data are discussed in relation to a model for epizootic and zoonotic cases possibly involving wild animals. Additional rigorous experiments are warranted to explore the value of this model in developing measures to prevent congenital brucellosis.
Subject(s)
Brucella abortus/immunology , Brucellosis/veterinary , Disease Models, Animal , Infectious Disease Transmission, Vertical/veterinary , Rats, Sprague-Dawley , Agglutination Tests/veterinary , Animals , Antibodies, Bacterial/blood , Brucella abortus/growth & development , Brucella abortus/isolation & purification , Brucellosis/transmission , Disease Transmission, Infectious/veterinary , Female , Male , Polymerase Chain Reaction/veterinary , RatsABSTRACT
To evaluate the transplacental transfer of Theileria sergenti infection in cattle, we used DNA probes to detect T. sergenti in 6 pregnant cows and their calves. All the animals were monitored by parasitologic, serologic, and polymerase chain reaction (PCR) assays for a predicted 875-base-pair (bp) DNA product and a 684-bp amplicon detected by nested PCR in the blood and spleens of aborted fetuses. An open reading frame (ORF) starting at nucleotide 170 and terminating at position 1021 was shown to code for a polypeptide of 283 amino acid residues. All 6 dams and 5 calves were positive for T. sergenti in all tests. One calf was positive only with nested PCR. We conclude that transplacental transmission of T. sergenti is a significant problem. The relevance of the data in the programmed introduction of new (especially pregnant) animals into established clean herds needs serious consideration with regard to control of theileriosis and other tickborne diseases.