Joe W. Templeton

Brucella abortus in captive bison. I. Serology, bacteriology, pathogenesis, and transmission to cattle.

Two groups of six, non-brucellosis vaccinated, brucellosis seronegative pregnant American bison (Bison bison) were individually challenged with 1 × 107 colony forming units (CFU) of Brucella abortus strain 2308. Three days after challenge, each bison group was placed in a common paddock with six non-vaccinated, brucellosis susceptible, pregnant domestic heifers. In a parallel study, two groups of six susceptible, pregnant cattle were simultaneously challenged with the identical dose as the bison and each group was placed with six susceptible cattle in order to compare bison to cattle transmission to that observed in cattle to cattle transmission. Blood samples were collected from bison and cattle weekly for at least 1 mo prior to exposure to B. abortus and for 180 days post-exposure (PE). Sera from the bison and cattle were evaluated by the Card, rivanol precipitation, standard plate agglutination, standard tube agglutination, cold complement fixation tube, warm complement fixation tube, buffered acidified plate antigen, rapid screening, bovine conjugated enzyme linked immunosorbent assay, bison or bovine conjugated enzyme linked immunosorbent assay, and the hemolysis-in-gel techniques for the presence of antibodies to Brucella spp. At the termination of pregnancy by abortion or birth of a live-calf, quarter milk samples, vaginal swabs, and placenta were collected from the dam. Rectal swabs were collected from live calves, and mediastinal lymph nodes, abomasal contents and lung were taken at necropsy from aborted fetuses for culture of Brucella spp. These tissues and swabs were cultured on restrictive media for the isolation and identification of Brucella spp. Pathogenesis of brucellosis in bison was studied in an additional group of six pregnant bison which were challenged with 1 × 107 CFU of B. abortus strain 2308. One animal was euthanatized each week PE. Tissues were collected at necropsy and later examined bacteriologically and histologically. Lesions of brucellosis in bison did not significantly differ grossly or histologically from those in cattle. There were six abortions and two nonviable calves in the bison group, as compared to nine abortions in the 12 similarly inoculated cattle. As determined by bacterial isolations, transmission of B. abortus from bison to cattle (five of 12 susceptible cattle became infected) did not differ statistically from cattle to cattle transmission (six of 12 susceptible cattle became infected) under identical conditions. No single serologic test was consistently reliable in diagnosing B. abortus infected bison for 8 wk PE. Multiple testing periods in which the Card test was used in combination with the bison conjugated enzyme linked immunosorbent assay and the hemolysis-in-gel proved to be a useful battery of serologic techniques to diagnose brucellosis in bison after the initial 8 wk PE.

Fresh and cryopreserved venous allografts in genetically characterized dogs

The autogenous saphenous vein is universally accepted as the conduit of choice for arterial bypass procedures in small vessels. Unfortunately, 2030% [S] of patients do not possess an adequate saphenous vein because of previous vein stripping, thrombophlebitis, or venous anomalies. Abundant laboratory and clinical research to date has failed to produce a uniformly successful prosthetic graft for small vessel application, although modest progress has been made in recent years. Attention has inevitably turned to the possible use of venous allografts in those patients requiring small vessel bypass procedures who do not possess an adequate saphenous vein. Considerable investigative and clinical data have been accumulated on the use of venous allografts in arterial surgery since the beginning of this century. With several isolated exceptions [21, 221, the use of venous allografts in patients has been disappointing to data. Many investigatars, however, feel the venous allograft may have a role in future arterial surgery if the allograft can either be antigenically modified prior to implantation or if the immunologic reactivity of the host can be modified. A recent important paper by Weber ef al. [24] indicated a marked improvement in the function of venous allografts following cryo-

BRUCELLA ABORTUS IN BISON. II. EVALUATION OF STRAIN 19 VACCINATION OF PREGNANT COWS

Protection against Brucella abortus induced abortion and infection provided by strain 19 (S19) vaccination was evaluated in American bison (Bison bison) Forty-eight pregnant bison were manually inoculated (MI) with S19 vaccine, 44 were ballistically inoculated (BI) with an absorbable hollow pellet containing lyophilized SI9, and 46 were manually injected with buffered saline as non-vaccinated controls (NVC). All bison were Brucella spp. seronegative prior to the experiment, in the second trimester of pregnancy, and were randomly assigned to experimental groups. Approximately 60 days post-vaccination, abortions were observed in the vaccinated bison. Brucella abortus strain 19 was recovered from a bison that had recently aborted, her fetus, and from 11 of 12 other aborted fetuses. Fifty-eight percent (53 of 92) of vaccinated bison aborted, and no abortions were observed in the NVC bison. One cow aborted during her second postvaccinal pregnancy and S19 was identified from the dam and fetus indicating that chronic S19 infections can occur in bison. Positive antibody titers were present 10 mo post-vaccination in 73% (66 of 91) of the bison. Thirteen mo post-vaccination, 30 MI vaccinates, 27 BI vaccinates, and 30 NVC bison were challenged during the second trimester of pregnancy with 1 × 107 CFU of B. abortus strain 2308 via bilateral conjunctival inoculation. Protection against abortion was 67% (P ≤ 0.0001) for vaccinated bison compared to 4% in NVC. Protection against B. abortus infection was determined to be 39% (P ≥ 0.001) for vaccinates and 0% (zero of 30) for NVC. Persistent antibody titers, vaccine induced abortions, and chronic S19 infections indicate that the S19 vaccine doses used in this study are not suitable for pregnant bison.

THE PATHOGENICITY OF BRUCELLA SUIS BIOVAR 4 FOR BISON

The pathogenicity of Brucella suis biovar 4 for bison (Bison bison) was evaluated by inoculation of 2.1 × 107 colony forming units (CFU) in 0.1 ml saline into the conjunctival sac of six pregnant cows. Six pregnant bison were inoculated with 1.27 × 107 CFU of Brucella abortus strain 2308 as a positive control. Bison were inoculated on 23 January 1992, and observed until calving or abortion after which they were euthanized, and necropsied. Bacteriological and histological examinations were conducted on lymph nodes, reproductive tract, mammary gland, and internal organs. Terminal serum samples from calves and cows were evaluated by card, rivanol precipitation, standard tube agglutination, cold complement fixation tube, indirect bison conjugated enzyme linked immunosorbent assay (ELISA), competitive ELISA, and particle-concentration fluorescence immunoassay. No clinical signs of brucellosis were seen in bison inoculated with B. suis biovar 4, and infection was found only in lymph nodes of two animals. There was no evidence of metastasis of this organism to the mammary gland or the reproductive tract. There were no detectable levels of antibodies to Brucella spp. in terminal blood samples taken from B. suis biovar 4-challenged bison. Brucella abortus was isolated from several tissues in all control bison. All B. abortus-challenged animals developed uterine infection and five developed mam-mary gland infection. Reproductive disease resulted in abortions in five B. abortus-challenged bison and neonatal death in the remaining calf. Brucella suis biovar 4 does not appear to be pathogenic for bison.

Canine erythrocyte pyruvate kinase. II. Properties of the abnormal enzyme associated with hemolytic anemia in the basenji dog

We have compared the solubility, kinetic, immunological, and electrophoretic properties of erythrocyte pyruvate kinase from normal dogs and Basenji dogs with congenital hemolytic anemia due to pyruvate kinase deficiency. Differences can be detected between the two enzymes by all methods. The enzyme from the affected animals has a greater solubility in ammonium sulfate. It has a lower Km for phosphoenolpyruvate, while the Km for ADP is increased. This enzyme is not inhibited by ATP or activated by fructose 1,6-diphosphate. The enzyme from the affected animals has none of the allosteric properties characteristic of the normal canine enzyme. No difference can be detected by enzyme inactivation with rabbit antiserum against the human erythrocyte enzyme, but a slight spur is observed on comparison of the two enzymes by Ouchterlony immunodiffusion. The enzymes also differ in their electrophoretic mobilities on starch gel electrophoresis.