Experimental Infection of Richardson’s Ground Squirrels (\u3ci\u3eSpermophilus Richardsonii\u3c/i\u3e ) With Attenuated and Virulent Strains pf \u3ci\u3eBrucella abortus\u3c/i\u3e

A previous investigation of the safety of Brucella abortus strain RB51 (sRB51) in various nontarget species suggested that Richardson’s ground squirrels (Spermophilus richardsonii) may develop persistent infections when orally inoculated with the vaccine. In the present study, sRB51, B. abortus strain 19 (s19), and virulent B. abortus strain 9941 (s9941) were administered orally to Richardson’s ground squirrels to further characterize B. abortus infection in this species. Six groups of nongravid ground squirrels were orally inoculated with 6x108 colony forming units (cfu) sRB51 (n=10), 2.5x104 cfu s19 (n=10), 2.5x107 cfu s19 (n=6), 1.3x106 cfu s9941 (n=5), 2.1x108 cfu s9941 (n=5), or vaccine diluent (control; n=4). One of five animals in the lower-dose s19 group and two of three animals in the higher-dose s19 group showed persistence of bacteria in various tissues at 14 wk post-inoculation (PI). At 18 wk PI, one of five animals in the sRB51 group and one of five animals in the high-dose s9941 group were culture positive. Although we did detect some persistence of B. abortus strains at 18 wk, we found no evidence of pathology caused by B. abortus strains in nonpregnant Richardson’s ground squirrels based on clinical signs, gross lesions, and microscopic lesions

CLINICOPATHOLOGIC FEATURES OF INFECTION WITH NOVEL BRUCELLA ORGANISMS IN CAPTIVE WAXY TREE FROGS (\u3ci\u3ePHYLLOMEDUSA SAUVAGII\u3c/i\u3e) AND COLORADO RIVER TOADS (\u3ci\u3eINCILIUS ALVARIUS\u3c/i\u3e)

Two novel and distinct Brucella strains were recovered from 5 of 10 adult, sex undetermined, captive waxy tree frogs (Phyllomedusa sauvagii) and two of five adult, sex undetermined, captive Colorado river toads (Incilius alvarius) held in a zoologic collection with clinical and pathologic findings of bacterial disease. These amphibians originated from three separate private breeding facilities over several years and exhibited disease 9–49 mo following release from quarantine. Common presenting signs were vague but included focal abscessation, weight loss, change in coloration, anorexia, and decreased perching. Two waxy tree frogs and one Colorado river toad recovered with supportive care and antimicrobial treatment based on susceptibility testing. Microgranulomatosis, subcutaneous and renal abscessation, femoral osteomyelitis, and multicentric infection were the most common histologic findings. The organisms were identified antemortem in samples from subcutaneous abscesses, cloaca, and skin and from a variety of organ systems postmortem, and demonstrated a consistent susceptibility pattern. Initial isolates were misidentified as Ochrobactrum anthropi. Polymerase chain reaction and sequencing of the 16S rRNA gene identified the two organisms as novel Brucella strains similar to Brucella inopinata–like sp. and other novel organisms within the emerging ‘‘BO clade.’’ Brucella strain oaks (isolated from waxy tree frogs) and Brucella strain leathers (isolated from Colorado river toads) differed from each other by 16 of 571 base pairs in a region of chromosome 2, and did not closely match any previous GenBank entries. This report describes the clinicopathologic features of infection by these bacteria in two amphibian species and expands the range of novel Brucella organisms from amphibian reservoirs

Vaccines against sexually transmitted diseases

Human sexually transmitted infections are prevalent throughout the world. Several have been associated with adverse pregnancy outcome and increased susceptibility to HIV infection, in addition to the discomfort of inflammation of the genital tract. Yet vaccines to protect against the infection at the genital mucosa are not available. Hepatitis B is an exception, but this virus becomes systemic and protection may be at the systemic level. Sexually transmitted diseases (STDs) have long been associated with reproductive failure in cattle. These infections cause considerable economic loss, which has been a stimulus to investigation. Consequently, vaccines and mechanisms of immune protection have been studied quite thoroughly. The results obtained with two commercially available vaccines will be used to illustrate principles of protective immunity against STDs. Both Campylobacter fetus subsp. venerealis and Tritrichomonas foetus are only transmitted sexually and both cause reproductive failure in cattle

Safety Of \u3ci\u3eBrucella Abortus\u3c/i\u3e Strain Rb51 In Black Bears

In two studies conducted from October 1999 to March 2000 and December 2000 to April 2001, adult black bears (Ursus americanus) were orally inoculated with 1.4–3.1X1010 colony-forming units (CFU) of Brucella abortus strain RB51 (SRB51, n=12) or 2 ml of 0.15 M NaCl solution (saline, n=11). We did not detect a difference (P\u3e0.05) in antibody titers to SRB51 in serum obtained before vaccination, at 8 wk after vaccination, or at necropsy at 21 or 23 wk after vaccination between SRB51-vaccinated and nonvaccinated bears. The SRB51 vaccine strain was recovered from tissues obtained at necropsy from one of six SRB51-vaccinated bears in study 1, but none of the six SRB51-vaccinated bears in study 2. Vaccination of black bears with SRB51 did not appear to influence (P\u3e0.05) reproductive performance

Anti-prion activity generated by a novel vaccine formulation

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of domestic and wild cervids in North America. To address possible prevention regimens for CWD, we have used a mouse model system and the Rocky Mountain Laboratory (RML) mouse-adapted scrapie prion strain to screen efficacy of potential vaccine candidates. Three peptides derived from the primary amino acid sequence of the prion protein were conjugated to blue carrier protein (BCP) and formulated in an adjuvant containing M. avium subsp. avium. CL57/BL6 mice were vaccinated and boosted with 50 µg of the carrier protein–peptide conjugate formulation; all vaccines produced a humoral immune response as measured by ELISA. Disease challenge with the RML scrapie prion strain revealed anti-prion activity was generated by the vaccine formulations as measured by a delay in clinical disease onset and prolonged survivorship

Comparison of Endocrine Response to Stress Between Captive-Raised and Wild-Caught Bighorn Sheep

Stress hormones in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), produced in response to environmental changes, road development, or high population density, may impact their immune systems to a threshold level that predisposes them to periodic, large-scale mortality. We compared the stress response to a novel environmental situation and repeated handling between bighorn sheep born and raised in captivity (CR) and bighorn sheep born in the wild (WC) and brought into captivity. We measured plasma epinephrine, norepinephrine, cortisol, and fecal glucocorticoid metabolites (FGM). Three weeks after each group’s arrival we used a one-time drop-net event to elicit an acute stress response, and we collected blood samples from each sheep over 35 minutes, as well as one fecal sample. We collected blood and fecal samples from both groups on 7 other occasions over the subsequent 6 months. We also collected fecal samples from the pen at approximately 24-hour intervals for 3 days following every handling event to monitor the stress response to handling. We found that CR sheep had a stronger autonomic nervous system response than WC sheep, as measured by epinephrine and norepinephrine levels, but we found a very similar hypothalamic–pituitary–adrenal axis (HPA) response, measured by cortisol levels, to the acute stress event of a drop-net restraint. We also found that once the WC sheep had acclimated, as indicated by the return to the initial baseline FGM levels within 12 weeks, the CR and WC groups’ HPA responses to sampling events were not significantly different from one another. Fecal samples can provide a noninvasive mechanism for managers to monitor baseline FGM for a given herd. Using long-term monitoring of FGM rather than values from a single point in time may allow managers to correlate these levels to outside influences on the herd and better understand the impacts of management changes, population density, or increased human developments on the health of the sheep population

Production of embryos and a live offspring using post mortem reproductive material from bison (Bison bison bison) originating in Yellowstone National Park, USA

Bison from Yellowstone National Park (YNP) have an important genetic history. As one of the few wild herds of bison with no evidence of cattle DNA introgression and a large enough population to maintain genetic diversity, they are considered a conservation priority for the species. Unfortunately, there is a high prevalence of the zoonotic disease brucellosis in the herd. Part of the management strategy for controlling the disease and herd size in YNP is to remove bison from the population during the winter migration out of the park. This interagency management cull provides an opportunity to collect a large number of oocytes from a wild bison population for genetic banking and research purposes. During the winters of 2014–2018, which is the nonbreeding season for bison, oocytes were collected post mortem and used to determine the effects of donor reproductive maturity and pregnancy status on oocyte quality and in vitro fertilization (IVF) outcomes, and to demonstrate the feasibility of producing healthy offspring. Cumulus oocyte complexes (COCs) were placed into an in vitro embryo production (IVP) system, and on days 7, 7.5, and 8 of in vitro culture (Day 0 = day of in vitro fertilization) embryos were assessed for developmental stage and quality prior to vitrification. Embryos were then stored in liquid nitrogen until the breeding season when a subset were warmed, cultured for 6 h, evaluated for survival, and transferred to healthy bison recipients. There were no significant differences in the ability of recovered COCs to support blastocyst development based on female reproductive maturity or pregnancy status (juvenile 79/959 (8.2%) vs sexually mature 547/6544 (8.4%); non-pregnant 188/2302 (8.2%) vs pregnant 556/6122 (9.1%)). Following the transfer of 15 embryos to 10 recipients, one healthy female calf was born. This work demonstrates that live offspring can be generated from COCs collected from YNP bison post mortem in the non-breeding season, and that gamete recovery can be a valuable tool for conservation of valuable genetics for this species while mitigating diseases like brucellosis

Evaluation of antibody response to an adjuvanted hapten-protein vaccine as a potential inhibitor of sexual maturation for farmed Atlantic salmon

An experimental contraceptive vaccine was evaluated in Atlantic salmon (Salmo salar). A peptide derived from the beta subunit of luteinizing hormone (LH) was conjugated to two different carrier proteins, bovine serum albumin (BSA) and keyhole limpet hemocyanin (KLH), and formulated with one of four immunostimulants in a water-in-oil emulsion. Specific antibody responses to the peptide and each carrier protein were evaluated. While the antibody response to KLH was stronger than the response to BSA, both carrier proteins stimulated comparable antibody responses to the LH peptide. The immunostimulant proved to be more important for enhancing the LH peptide antibody response than the carrier protein selection; vaccines containing a combination of Aeromonas salmonicida and Vibrio anguillarum stimulated significantly greater LH peptide antibody production than any of the other three immunostimulants evaluated at 12 weeks post-vaccination. This study provides proof-of-concept for specific antibody production against a hapten-carrier protein antigen in Atlantic salmon and reinforces the importance of vaccine immunostimulant selection