Pathology of brucellosis in bison from Yellowstone National Park

Between February 1995 and June 1999, specimens from seven aborted bison (Bison bison) fetuses or stillborn calves and their placentas, two additional placentas, three dead neonates, one 2-wk-old calf, and 35 juvenile and adult female bison from Yellowstone National Park (USA) were submitted for bacteriologic and histopathologic examination. One adult animal with a retained placenta had recently aborted. Serum samples from the 35 juvenile and adult bison were tested for Brucella spp. antibodies. Twenty-six bison, including the cow with the retained placenta, were seropositive, one was suspect, and eight were seronegative. Brucella abortus biovar 1 was isolated from three aborted fetuses and associated placentas, an additional placenta, the 2-wk-old calf, and 11 of the seropositive female bison including the animal that had recently aborted. Brucella abortus biovar 2 was isolated from one additional seropositive adult female bison. Brucella abortus was recovered from numerous tissue sites from the aborted fetuses, placentas and 2-wk-old calf. In the juvenile and adult bison, the organism was more frequently isolated from supramammary (83%), retropharyngeal (67%), and iliac (58%) lymph nodes than from other tissues cultured. Cultures from the seronegative and suspect bison were negative for B. abortus. Lesions in the B. abortus-infected, aborted placentas and fetuses consisted of necropurulent placentitis and mild bronchointerstitial pneumonia. The infected 2-wk-old calf had bronchointerstitial pneumonia, focal splenic infarction, and purulent nephritis. The recently-aborting bison cow had purulent endometritis and necropurulent placentitis. Immunohistochemical staining of tissues from the culture-positive aborted fetuses, placentas, 2-wk-old calf, and recently-aborting cow disclosed large numbers of B. abortus in placental trophoblasts and exudate, and fetal and calf lung. A similar study with the same tissue collection and culture protocol was done using six seropositive cattle from a B. abortus-infected herd in July and August, 1997. Results of the bison and cattle studies were similar.     

Antibodies against Mycoplasma bovigenitalium in free-living European bison (Bison bonasus) with balanoposthitis

Since 1980 severe chronic balanoposthitis has been observed in free-living European bison (Bison bonasus) in the Bia?owieza Primeval Forest (Poland). Sera of 50 bison with balanoposthitis and 48 clinically healthy male and 49 female bison were investigated for antibodies against Mycoplasma bovis and M. bovigenitalium by western blot analysis. Prevalence of antibodies against M. bovigenitalium was significantly higher in bison with balanoposthitis than in unaffected male bison. Mycoplasma bovigenitalium may play a role in the pathogenesis of balanoposthitis in European bison.     

Characterization of Anaplasma marginale isolated from North American bison

Anaplasma marginale (Rickettsiales: Anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. Although serologic tests have identified American bison, Bison bison, as being infected with A. marginale, the present study was undertaken to confirm A. marginale infection and to characterize isolates obtained from naturally infected bison in the United States and Canada. Major surface protein (MSP1a and MSP4) sequences of bison isolates were characterized in comparison with New World cattle isolates. Blood from one U.S. bison was inoculated into a susceptible, splenectomized calf, which developed acute anaplasmosis, demonstrating infectivity of this A. marginale bison isolate for cattle. The results of this study showed that these A. marginale isolates obtained from bison were similar to ones from naturally infected cattle.     

Contraception of bison by GnRH vaccine: a possible means of decreasing transmission of brucellosis in bison

Preventing pregnancy in brucellosis-infected bison (Bison bison) provides a potential means of preventing transmission of disease. To determine whether a gonadotropin-releasing hormone (GnRH) vaccine was effective in reducing pregnancy in bison and to study the safety of injecting GnRH in pregnant bison, a study was conducted at the Idaho Fish and Game Wildlife Health Laboratory in Caldwell, Idaho (USA). Four pregnant and two nonpregnant female bison were given a single injection of GnRH vaccine, and five pregnant adult females were given a sham injection that contained only adjuvant. Three of the GnRH-vaccinated bison that were pregnant at the time of vaccination delivered healthy calves. One treated bison had dystocia that resulted in a dead calf. All control bison delivered healthy calves. After calving, females of both groups were exposed to two bulls. Treated bison were palpated 6 wk after exposure to the bulls, and blood was drawn for pregnancy-specific protein B analysis. The six treated bison were not pregnant. The sham-treated bison became pregnant and delivered viable calves. This study demonstrates that a single dose of GnRH vaccine is effective in preventing pregnancy in female bison for at least 1 yr.     

Infectivity of sarcocystis spp. from bison, elk, moose, and cattle for cattle via sporocysts from coyotes

Bison bison (bison), Cervus canadensis (elk), Alces alces (moose), and Bos taurus (cattle) musculature containing Sarcocystis spp. cysts was fed to laboratory raised Canis latrans (coyotes), Sporocysts collected from the feces of coyotes fed musculature of each of the ruminant species were fed to four groups of three laboratory-raised domestic calves, respectively, to determine if Sarcocystis spp. was transmissible from wild to domestic ruminants and if so, to compare clinical signs of infection and morphologic features of cysts with those resulting from infection with Sarcocystis bovicanis. All calves fed sporocysts of Sarcocystis from coyotes that ate bison or cattle muscle had similar clinical signs and harbored morphologically similar parasites, suggesting that both bison and cattle are intermediate hosts for S. bovicanis and that this species is transmissible between the two ruminant species. All calves fed sporocysts from coyotes that ate elk muscle or moose muscle remained asymptomatic but one calf in each group had intramuscular cysts. The finding of relatively large numbers of intramuscular cysts in one calf fed sporocysts of elk origin and smaller numbers in one calf fed sporocysts of moose origin could represent either spurious natural infections or indicate low infectivity of Sarcocystis spp. from elk and moose to cattle.     

Immune responses of bison to ballistic or hand vaccination with Brucella abortus strain RB51

From January through July of 2000, a study was conducted to evaluate clearance, immunologic responses, and potential shedding of Brucella abortus strain RB51 (SRB51) following ballistic or subcutaneous (SQ) vaccination of 7 mo old bison (Bison bison) calves. Ten bison calves were vaccinated SQ with 1.4 x 10(10) colony-forming units (CFU) of SRB51 and five calves were inoculated SQ with sterile 0.15 M sodium chloride. An additional 10 bison calves were ballistically inoculated in the rear leg musculature with 1 x 10(10) CFU of SRB51 and five calves were ballistically inoculated with an empty Biobullet. Serologic responses were monitored at 0, 2, 4, 6, 8, 12, 18, and 24 wk using the standard tube agglutination test and a dot-blot assay. Swabs from rectal, vaginal, nasal, and ocular mucosal surfaces, and blood were obtained for culture from all bison at 2, 4, 6, and 8 weeks post-inoculation to evaluate potential shedding by vaccinated bison or persistent septicemia. The superficial cervical lymph node was biopsied in eight ballistic and eight hand vaccinated bison at 6 or 12 wk to evaluate clearance of the vaccine strain from lymphatic tissues. Lymphocyte proliferative responses to irradiated SRB51 bacteria were evaluated in peripheral blood mononuclear cells (PBMC) at 4, 6, 8, 12, 18, and 24 wk after inoculation. Serum obtained from hand or ballistically vaccinated bison demonstrated antibody responses on the dot-blot assay that were greater than control bison (saline or empty Biobullet) at 2, 4, 6, and 8 wk after vaccination. Antibody titers of ballistically vaccinated bison did not differ (P > 0.05) from hand vaccinated bison at any sampling time. Blood samples obtained from all bison at 2, 4, 6 and 8 wk after vaccination were negative for SRB51. One colony of SRB51 was recovered from the vaginal swab of one ballistically vaccinated bison at 2 wk after vaccination. All other ocular, vaginal, nasal, and rectal swabs were culture negative for SRB51. Strain RB51 was recovered from superficial cervical lymph nodes of hand and ballistic vaccinated bison at 6 (two of four and two of four bison, respectively) and 12 wk (three of four and one of four bison, respectively). Serologic tests and bacterial culture techniques failed to demonstrate infection of nonvaccinated bison. Peripheral blood mononuclear cells obtained from hand vaccinated bison had greater (P < 0.05) proliferative responses to strain RB51 bacteria when compared to PBMC from nonvaccinated and ballistically vaccinated bison. Proliferative responses of PBMC from ballistically vaccinated bison did not differ (P > 0.05) at any sampling time from proliferative responses of PBMC from control bison. Serum alpha 1-acid glycoprotein concentrations, plasma fibrinogen, and total protein concentrations were not influenced by treatments. Ballistic delivery of SRB51 did not induce adverse effects or influence clearance of the vaccine strain. There were no proliferative responses of PBMC to SRB51 in bison ballistically vaccinated with SRB51; whereas bison inoculated with SRB51 by hand injection had greater proliferative responses than control or ballistically vaccinated bison. Our study suggests that ballistic delivery may require a greater dose of SRB51 to induce cell-mediated immune responses in bison that are comparable to those induced by hand injection, and that ballistic or hand delivery of 1 x 10(10) CFU of SRB51 is safe in bison calves.     

Characterization of Anaplasma marginale Isolated from North American Bison

Anaplasma marginale (Rickettsiales: Anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. Although serologic tests have identified American bison, Bison bison, as being infected with A. marginale, the present study was undertaken to confirm A. marginale infection and to characterize isolates obtained from naturally infected bison in the United States and Canada. Major surface protein (MSP1a and MSP4) sequences of bison isolates were characterized in comparison with New World cattle isolates. Blood from one U.S. bison was inoculated into a susceptible, splenectomized calf, which developed acute anaplasmosis, demonstrating infectivity of this A. marginale bison isolate for cattle. The results of this study showed that these A. marginale isolates obtained from bison were similar to ones from naturally infected cattle.     

Assessment of S100 protein expression in the epididymis of juvenile and adult European bison

In our study, we decided to compare S100 protein expression in the material obtained from the epididymes of 5- and 12-month-old calves, and adult European bison, and to detect any differences in S100 expression according to the animal age and size of the organ examined. We used the epididymes obtained from 6 adult European bison aged 6-12 years, from 6 at the age of 12 months and 6 calves aged 5 months. Immunocytochemical reactions were performed using the avidin-biotinylated-peroxidase (ABC) technique according to HSU. Specific polyclonal rabbit antiserum against bovine S100 protein (Bio Genex Laboratories) at a dilution at 1:400 was applied. We found the expression of S100 protein in endothelial cells of arteries, veins and lymphatic vessels in all the study animals. At the same time, we found no differences in the expression of S100 protein in vascular endothelial cells. Our observations seem to indicate that S100 expression in endothelial cells of European bison epididymis is not correlated with age or maturity of the organ tested. We found S100 protein in smooth muscle cells of arteries and veins in all European bison specimens examined. Interestingly in the current study, in young 5-month-old sexually immature European bison specimens we observed weaker expression of S100 protein in smooth muscle cells of small vessels as compared to the same cell type both in large vessels in these animals and in small vessels in adult specimens.     

Brucellosis in elk of eastern Idaho

Brucellosis occurs in free-ranging elk (Cervus elaphus) and bison (Bison bison) in the Greater Yellowstone Area, which includes portions of Idaho, Wyoming, and Montana. Brucella abortus was first detected in elk in Idaho in 1998, and from 1998 to 2002, serologic surveillance of hunter-killed elk was conducted in northeastern and southeastern Idaho. Prevalence of antibodies in these elk varied annually, but averaged between 2% and 3%. Elk were also trapped in northeastern Idaho from 1998-2002 and tested for brucellosis using serology and tissue culture. In areas where artificial feeding of elk was done, antibody prevalence ranged from 12% to 80% depending on site, age, and sex. At one feeding site (Rainey Creek), a decline in the prevalence of antibodies (from 56.8% in 1999 to 13.5% in 2002) was detected after the removal of seropositive elk over 4 yr. Seropositive elk removed from two artificial winter feeding sites (Rainey Creek and Conant Creek) were euthanized and sampled or held in captivity and allowed to calve prior to euthanasia and necropsy. At necropsy, B. abortus biovar 1 and B. abortus biovar 4 were isolated from both cows and calves; however, biovar 4 was predominant. A dual infection with both biovars was found in one calf born to a seropositive cow from which biovar 4 was isolated. Abortions (16%), stillbirths (8%), and weak calves (4%) were observed in these elk. These findings confirm the presence of brucellosis in elk in eastern Idaho and provide information on disease management options.     

Validation of the fluorescence polarization assay and comparison to other serological assays for the detection of serum antibodies to Brucella abortus in bison

A number of serological tests were compared for the detection of antibodies to Brucella abortus in bison (Bison bison). The performance of the fluorescence polarization assay (FPA) in both the preliminary evaluation and a subsequent blind validation indicated that this test was the most suitable for serological diagnosis of brucellosis in bison. The sensitivity and specificity in the preliminary evaluation were 92.1% and 99.4%, respectively. The sensitivity and specificity in a subsequent blind study were 96.3% and 97.6%, respectively. In a double blind study conducted on bison vaccinated with B. abortus strain 19, the data suggests that the FPA can differentiate bison infected with B. abortus from bison vaccinated with B. abortus strain 19. Both the indirect immunoassay (IELISA) and the competitive immunoassay (CELISA) performed nearly as well as the FPA. The buffered antigen plate agglutination test (BPAT) and the complement fixation test (CFT) did not perform as well as the FPA, CELISA or the IELISA in both studies. The FPA is a homogeneous assay eliminating the washing steps and reducing incubation to minutes rather than hours saving on time, equipment, materials, reagents and cost. These attributes, together, with its excellent sensitivity and specificity make the FPA an attractive test for the detection of serum antibodies to Brucella abortus in bison.     

Virologic investigations of free-living European bison (Bison bonasus) from the Bialowieza Primeval Forest,Poland

We conducted virologic investigations on postmortem specimens from 261 free-living European bison (Bison bonasus) from the Bialowieza Primeval Forest, Poland collected between 1990 and 2000. Fifty-four of 94 males had balanoposthitis; none of the 167 female bison examined had reproductive tract lesions. Peripheral blood, swabs, and various tissues were analyzed for bovine viruses as well as for viral DNA by bovine herpesvirus 1 (BoHV-1) and bovine herpesvirus 4 (BoHV-4) specific polymerase chain reaction (PCR) technique. An infectious bovine rhinotracheitis like BoHV-1 strain was isolated from the spleen of a female bison calf and additionally was detected by nested PCR from splenic tissue. None of the bison had significant antibody titers against BoHV-1, bovine herpesvirus 2, BoHV-4, caprine herpesvirus 1, cervid herpesvirus 1, or bovine viral diarrhea (BVD) virus-1. However, low antibody titers in two animals indicate that this European bison population has been exposed to BVD virus or BVD-like viruses and BoHV-2.     

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 x 10(7) 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 x 10(7) 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 constantly reliable to diagnosing B. abortus infected bison for 8 wk PE.(ABSTRACT TRUNCATED AT 400 WORDS)     

Serologic survey for selected microbial pathogens in bison from Kansas.

A serologic survey was conducted on an American bison (Bison bison) herd in Kansas for antibodies against Brucella spp., Leptospira interrogans serovar canicola, pomona, grippotyphosa, icterohaemorrhagiae, and hardjo, Anaplasma spp., bluetongue virus, infectious bovine rhinotracheitis virus and bovine viral diarrhea virus. There was an increase in prevalence of bluetongue antibodies from 38% in 1987 to 100% in 1989 in animals greater than or equal to 24-mo-old. Prevalences of antibodies against the other livestock pathogens were either negative or at levels associated with previous vaccination.     

Prevalence of antibodies to Neospora caninum in wild animals

Antibodies to Neospora caninum were determined in several species of wild animals in the United States by the Neospora agglutination test (NAT). Antibodies (NAT 1:40 or higher) were found in 5 of 249 bison (Bison bison), 5 of 160 caribou (Rangifer tarandus), 4 of 162 moose (Alces alces), 4 of 122 wolves (Canis lupus), and 1 of 224 musk ox (Ovibos moschatus) but not in 197 black bears (Ursus americanus). To our knowledge, this is the first report of antibodies to N. caninum in bison and caribou. The total absence of N. caninum antibodies in black bears indicates that bears are not a host for N. caninum and that there is no cross-reactivity between the NAT and the modified agglutination test (MAT) for Toxoplasma gondii, because more than 80% of black bears in eastern United States have MAT antibodies at a 1:25 serum solution.     

Immunolocalization of PTHrP in the European bison and pine vole testis and epididymis

The present study deals with immunohistochemical localization of PTHrP in European bison and pine vole testis and epididymis. PTHrP immunoreactivity was observed in spermatogenic cells of seminiferous tubules in European bison and pine vole testis, with the strongerst reaction occurring in spermatozoa of pine vole testis and epididymal duct. We also observed PTHrP expression in vascular smooth muscle of epididymis and testis in both animal species, as well as slightly weaker reaction in endothelial cells of European bison epididymis. PTHrP was also expressed in the smooth muscle of the epididymal duct in European bison and pine vole. In conclusion, PTHrP is a multifunctional peptide showing both paracrine and autocrine action. Its presence in vascular endothelium and smooth muscle of testis and epididymis is connected with the regulation of vascular muscle tone, thus affecting blood flow in the vessels. PTHrP expression depends on a number of local factors. Moreover, we suppose that PTHrP also contributes to the proliferation and differentiation of spermatogenic cells.     

Serologic survey for bovine pathogens in free-ranging European bison from Poland

From 1980 to 1983, blood was taken from 60 selected European bison (Bison bonasus) in Poland. Serum samples were tested for the presence of antibodies against Brucella abortus, 14 serovars of Leptospira interrogans, Chlamydia spp., Coxiella burnetti; foot and and mouth disease virus, bovine leukemia virus and bovine herpes virus-1. In addition, an attempt was made to isolate bovine herpes virus-1 from the prepuce of selected bulls. Serological tests suggested chlamydial infection in 28 bison, subclinical Q-fever of a 2-yr-old heifer, subclinical bovine leukemia virus infection in a 12-yr-old bull and bovine herpes virus-1 infection in five bulls and three cows. Attempts to isolate bovine herpes virus-1 were not successful. These results suggest the possibility of cross transmission of several of these bovine pathogens between free-ranging bison and domestic cattle in Poland.     

Isolation and characterization of gelatin-binding bison seminal vesicle secretory proteins

Bovine seminal plasma (BSP) contains a family of major proteins designated BSP-A1/A2, BSP-A3, and BSP-30kDa (collectively called BSP proteins) that bind to sperm at ejaculation and potentiate sperm capacitation. Homologous proteins have been identified in stallion, boar, goat, and ram seminal plasma. We report here the isolation and characterization of homologous proteins from bison seminal vesicle secretions. Seminal vesicle secretory proteins were precipitated by adding cold ethanol and recovered by centrifugation. The precipitates were resuspended in ammonium bicarbonate, dialyzed, and lyophilized. Lyophilized proteins were dissolved in 0.05 M phosphate buffer (PB) and loaded onto a gelatin-agarose column. The unadsorbed proteins and adsorbed proteins were eluted with PB and 5 M urea in PB, respectively. The gelatin-adsorbed fraction was analyzed by SDS-PAGE and revealed the presence of four major proteins designated BiSV-16kDa, BiSV-17kDa, BiSV-18kDa, and BiSV-28kDa (BiSV: bison seminal vesicle proteins). Heparin-Sepharose chromatography allowed the separation of BiSV-16kDa, which did not bind heparin from other BiSV proteins, which bound heparin. Immunoblotting revealed that BiSV-16kDa cross-reacted with BSP-A3 antibodies, BiSV-17kDa and BiSV-18kDa cross-reacted with BSP-A1/-A2 antibodies, and BiSV-28kDa cross-reacted with BSP-30kDa antibodies. Radioimmunoassays indicated that approximately 25% of bison seminal vesicle total proteins are related to BSP proteins. The amino-terminal sequencing indicated that BiSV proteins share almost 100% sequence identity with BSP proteins. In addition, BiSV proteins bind to low-density lipoproteins isolated from hen's egg yolk. These results confirm that BSP protein homologs are present in mammalian seminal plasma and they may share the same biological role.     

Ruminal ciliated protozoa in bison

Ruminal contents from 79 slaughtered bison and 2 ruminally cannulated bison were collected to obtain information on total numbers and species distribution of ciliated protozoa. The bison originated from numerous herds throughout the Great Plains and were grouped into three dietary categories: (i) only forage; (ii) forage with moderate levels of supplementation; and (iii) feedlot concentrate-silage diet. Total ciliate counts were highest in bison receiving grain supplementation (210.1 x 10(4)/g) and lowest in bison consuming only forage (27.1 x 10(4)/g). All protozoan species found in bison have been reported in domestic livestock, although Ophryoscolex sp., a relatively common protozoan in cattle, was detected at low concentrations in only eight bison. The uncommon holotrich Microcetus lappus was present in five bison in concentrations reaching 8.4% of the total ciliate population. Charonina ventriculi, another infrequently observed species, was present in 18 bison, with the highest concentrations in forage-fed animals. Thirty bison possessed a type B protozoan population, characterized by Epidinium sp., Eudiplodinium maggii, and Eudiplodinium bovis. Thirty-eight bison possessed a mixed A-B population, characterized by Polyplastron sp. coexisting with low numbers of Eudiplodinium maggii or Epidinium sp. or both. Thirteen bison possessed populations lacking any remnant type B ciliate species. At least 29 of the bison possessing Polyplastron sp. were known to have been in contact with cattle, whereas all bison isolated from cattle had type B populations. The reduction of type B populations in bison becomes increasingly likely as bison production expands into areas inhabited by domestic livestock.