ABSTRACT
The purpose of this study was to characterize the exposure of bovine aborted fetuses from beef and dairy herds of the humid pampas of Argentina to different infectious agents by the evaluation of fetal fluid antibodies. Presence of fetal antibodies to bovine viral diarrhea virus genotype 1 (BVDV-1), bovine herpes virus type 1 (BHV-1), Leptospira interrogans, Brucella abortus, and Neospora caninum was determined. Of the 95 fetuses processed, 66 came from 49 beef herds and 29 from 12 dairy herds. The average gestational age of the aborted fetuses was 7.1 months. Antibodies to the mentioned agents were detected in 65 of the 95 fetal fluids (68.4
). In addition, antibodies to more than one infectious agent were detected in 32 fetuses (33.7
), suggesting fetal exposure to multiple antigens during gestation. There were antibodies to BVDV-1, BHV-1, N. caninum and Leptospira interrogans in 43 (45.2
) and 5 (5.2
) specimens, respectively. Antibodies to B. abortus were not detected in any of the fetal fluids. The results of this study provide information on the determination of antibodies in fluids from bovine aborted fetuses exposed to different infectious agents in the region.
ABSTRACT
The diagnostic efficiency of two hemoculture media for the detection of different species of Brucella strains was evaluated. Strains of Brucella melitensis, Brucella suis, Brucella abortus, Brucella ovis, and Brucella abortus S19 were used. Each strain was diluted in phosphate buffer saline (PBS) to obtain a concentration of 10(5) colony forming units/ml (CFU/ml). Blood from goats, pigs, cattle, and sheep was mixed with the bacterial suspension to obtain a final concentration minor or equal to 10(3) CFU/ml. These blood samples were inoculated into the following media: (i) Hemobrucella (HB), (ii) Tryptose citrated broth 2
(CTB), and (iii) Controls without blood for B. melitensis and B.suis. Subculture in dishes and CFU/ml counts were made at the 1st, 3rd, 8th, 10th, 20th, and 30th post-inoculation (PI) day. Best results were obtained in the HB medium for all strains, except for B. suis, which due to the presence of a contaminant did not reach its maximum development in this medium. All strains were recovered from both media at 24 h PI, except B. ovis that was isolated from HB at 72 h PI and was not recovered from CTB. All strains remained viable for a shorter period in CTB. Under the proposed experimental conditions the HB medium was more sensitive than CTB. Future experiments should evaluate the utility of this commercial medium in clinical cases of animal brucellosis.