Determinación de la composición botánica de la dieta seleccionada por el venado cola blanca (Odocoileus virginianus texanus) en el norte del estado de Nuevo León

Tesis (Maestría en Ciencias Especialista en Producción Animal) UANL

Diferenciación genética de poblaciones de venado cola blanca (Odocoileus virginianus Boddaert)

Tesis (Maestría en Ciencias Forestales) UANL

Predación de coyote Canis latrans texensis en venado cola blanca Odocoileus virginianus texanus en Anáhuac, Nuevo León, México

Tesis (Maestría en Ciencias con Especialidad en Manejo de Vida Silvestre) UANL

Presencia de anticuerpos para diferentes enfermedades del venado y otros rumiantes, en poblaciones de venado cola blanca texano (Odocoileus virginianus texanus) [por] José Francisco Martínez Plasencia.

Tesis (Maestría en Ciencias Forestales) U.A.N.L.

Evaluación del crecimiento de cervatos cola blanca texanos (odocoileus virginianus texanus), alimentados con diferentes fórmulas lácteas.

Tesis (Maestría en Ciencias Forestales) UANL, 2012.

Detección serológica de patógenos multi-especie en venado cola blanca (Odocoileus virginianus) en tres microrregiones del Noreste de México.

Tesis (Maestría en Ciencia Animal) UANL, 2013

Humoral Immune Responses of White-Tailed Deer (Odocoileus virginianus) to Mycobacterium bovis BCG Vaccination and Experimental Challenge with M. bovis

Monitoring of the kinetics of production of serum antibodies to multiple mycobacterial antigens can be useful as a diagnostic tool for the detection of Mycobacterium bovis infection as well as for the characterization of disease progression and the efficacy of intervention strategies in several species. The humoral immune responses to multiple M. bovis antigens by white-tailed deer vaccinated with BCG orally via a lipid-formulated bait (n = 5), orally in liquid form (n = 5), and subcutaneously (n = 6) were evaluated over time after vaccination and after experimental challenge with virulent M. bovis and were compared to the responses by unvaccinated deer (n = 6). Antibody responses were evaluated by using a rapid test (RT), a multiantigen print immunoassay (MAPIA), a lipoarabinomannan enzyme-linked immunosorbent assay (LAM-ELISA), and immunoblotting to whole-cell sonicate and recombinant antigen MPB83. MAPIA and RT detected minimal to no antibody responses over those at the baseline to multiple M. bovis antigens in vaccinated white-tailed deer after challenge. This was in contrast to the presence of more readily detectable antibody responses in nonvaccinated deer with more advanced disease. The LAM-ELISA results indicated an overall decrease in the level of production of detectable antibodies against lipoarabinomannan-enriched mycobacterial antigen in vaccinated animals compared to that in nonvaccinated animals after challenge. Immunoblot data were inconsistent but did suggest the occurrence of unique antibody responses by certain vaccinated groups to Ag85 and HSP70. These findings support further research toward the improvement and potential use of antibody-based assays, such as MAPIA, RT, and LAM-ELISA, as tools for the antemortem assessment of disease progression in white-tailed deer in both experimental and field vaccine trials.

Evaluation of Blood Assays for Detection of Mycobacterium bovis in White-Tailed Deer (Odocoileus virginianus) in Michigan

Surveillance and control activities related to bovine tuberculosis (TB) in free-ranging, Michigan white-tailed deer (Odocoileus virginianus) have been underway for over a decade, with significant progress. However, foci of higher TB prevalence on private lands and limited agency ability to eliminate them using broad control strategies have led to development and trial of new control strategies, such as live trapping, testing, and culling or release. Such strategies require a prompt, accurate live animal test, which has thus far been lacking. We report here the ability of seven candidate blood assays to determine the TB infection status of Michigan deer. Our aims were twofold: to characterize the accuracy of the tests using field-collected samples and to evaluate the feasibility of the tests for use in a test-and-cull strategy. Samples were collected from 760 deer obtained via five different surveys conducted between 2004 and 2007. Blood samples were subjected to one or more of the candidate blood assays and evaluated against the results of mycobacterial culture of the cranial lymph nodes. Sensitivities of the tests ranged from 46% to 68%, whereas specificities and negative predictive values were all .92%. Positive predictive values were highly variable. An exploratory analysis of associations among several host and sampling-related factors and the agreement between blood assay and culture results suggested these assays were minimally affected. This study demonstrated the capabilities and limitations of several available blood tests for Mycobacterium bovis on specimens obtained through a variety of field surveillance methods. Although these blood assays cannot replace mass culling, information on their performance may prove useful as wildlife disease managers develop innovative methods of detecting infected animals where mass culling is publicly unacceptable and cannot be used as a control strategy.

Aerosol Exposure of White-Tailed Deer (Odocoileus virginianus) to Mycobacterium Bovis

Tuberculosis due to Mycobacterium bovis affects both captive and free-ranging Cervidae in the United States. Various animal models have been developed to study tuberculosis of both humans and animals. Generally, tuberculosis is transmitted by aerosol and oral routes. Models of aerosol exposure of large animals to M. bovis are uncommon. In order to develop a reliable method of aerosol exposure of white-tailed deer (Odocoileus virginianus) to M. bovis, 12 healthy white-tailed deer, aged 8–10 mo, were infected by aerosol exposure to 2x105 to 1x106 colony forming units (CFU) (high dose, n=4) of M. bovis or 6x102 to 1.6 x 103 CFU (low dose, n=8) of M. bovis. Tuberculous lesions were more widely disseminated in deer receiving the high dose, while lesions in deer receiving the low dose were more focused on the lungs and associated lymph nodes (tracheobronchial and mediastinal). Aerosol delivery of M. bovis to white-tailed deer results in a reliable manner of experimental infection that may be useful for studies of disease pathogenesis, immune response, mycobacterial shedding, and vaccine efficacy.

Milk Containing Mycobacterium bovis as a Source of Infection for White-Tailed Deer Fawns (Odocoileus virginianus)

Setting:White-tailed deer represent the first wildlife reservoir of Mycobacterium bovis in the United States. The behavior of does with nursing fawns provides several potential mechanisms for disease transmission. Little information exists concerning transmission between doe and fawn, specifically transmammary transmission. Objective: Determine if fawns can become infected by ingestion of milk replacer containing M. bovis, thus simulating transmission from doe to fawn through contaminated milk. Design: Seventeen, 21-day-old white-tailed deer fawns were inoculated orally with 2x108 CFU (high dose, n=5), 2.5 x 105 to 2.5 x 106 CFU (medium dose, n=5), and 1x104 CFU (low dose, n=5) of M. bovis in milk replacer. Dosages were divided equally and fed daily over a 5-day period. Positive control fawns (n=2) received 1x105 CFU of M. bovis instilled in the tonsillar crypts. Fawns were euthanized and examined 35-115 days after inoculation and various tissues collected for bacteriologic and microscopic analysis. Results: All fawns in the tonsillar, high oral and medium oral dose groups developed generalized tuberculosis involving numerous organs and tissues by 35-84 days after inoculation. Three of five fawns in the low-dose oral group had tuberculous lesions in the mandibular lymph node, and one of five had lesions in the medial retropharyngeal lymph node when examined 115 days after inoculation. Conclusion: White-tailed deer fawns can become infected through oral exposure to M. bovis. Therefore, the potential exists for fawns to acquire M. bovis while nursing tuberculous does.

Lesion Development in White-tailed Deer (Odocoileus virginianus) Experimentally Infected with Mycobacterium bovis

The recent discovery of tuberculosis in free-living white-tailed deer in northeastern Michigan underscores the need for increased understanding of the pathogenesis of tuberculosis in wildlife species. To investigate lesion development in white-tailed deer, 32 deer were experimentally infected by intratonsilar instillation of 300 colony-forming units of Mycobacterium bovis. Three deer each were euthanatized and examined at days 15, 28, 42, and 56 after inoculation, and five deer each were euthanatized and examined at days 89, 180, 262, and 328 after inoculation. Microscopic lesions first were seen in the medial retropharyngeal lymph node and lung 28 and 42 days after inoculation, respectively. Lung lesions were present in 12 (38%) of 32 deer, involving 23 lung lobes. Left caudal and right middle and caudal lobes were involved in 17 (74%) of the 23 affected lung lobes. Lesions in the medial retropharyngeal lymph node first appeared as granulomas composed of aggregates of macrophages and Langhans-type giant cells. Some early granulomas contained centrally located neutrophils. As granulomas developed, neutrophils were replaced with a central zone of caseous necrosis that first showed signs of mineralization 42 days after inoculation. Granulomas increased in size as the zone of caseous necrosis expanded. Peripheral fibrosis, first seen at 56 days after inoculation, progressed to only a thin fibrous capsule by 328 days after inoculation. By the termination of the study, the central necrotic core of the granuloma contained abundant liquefied necrotic material and grossly resembled an abscess. Although tuberculous lesions in white-tailed deer follow a developmental pattern similar to that in cattle, fibrosis is less pronounced and the advanced lesions may liquefy, a change seldom reported in cattle. An understanding of lesion development will aid in the identification of the spectrum of disease that may be seen in this important wildlife reservoir of tuberculosis.

Tuberculin Skin Testing in White-Tailed Deer (Odocoileus virginianus)

The comparative cervical skin test for antemortem diagnosis of tuberculosis was done 169 times on 116 different white-tailed deer of known Mycobacterium bovis infection status. The sensitivity and specificity were 97 and 81%, respectively. The magnitude of change in skin thickness at test sites was not significantly influenced by dosage of inoculum, dissemination of the disease process, or repeated skin testing. However, the magnitude of change in skin thickness was significantly greater in deer infected for less than 109 days than in deer infected for more than 109 days. As used in the present study, the comparative cervical skin test is a sensitive method of antemortem diagnosis of M. bovis infection in white-tailed deer.

Survival of Mycobacterium bovis on Feedstuffs Commonly Used as Supplemental Feed for White-tailed Deer (Odocoileus virginianus)

Mycobacterium bovis, the causative agent of bovine tuberculosis, has become established in free-ranging white-tailed deer Odocoileus virginianus in northeastern Michigan. The practice of supplemental feeding of white-tailed deer during the winter is believed to contribute to transmission of M. bovis between deer. The current study was conducted to determine the ability of M. bovis to survive on various feedstuffs commonly used as supplemental feed for deer in northeast Michigan (i.e., apples, corn, carrots, sugar beets, potatoes, and hay) and the effect of maintenance at 220 C, 8 C, and 23 C on survival. Mycobacterium bovis survived on all feedstuffs at all temperatures tested for at least 7 days. At 23 C, M. bovis could still be isolated from samples of apples, corn and potatoes at 112 days. This study suggests that contamination of feedstuffs by M. bovis-infected deer could act as a source of indirect transmission between deer because M. bovis is able to survive in temperatures similar to those recorded during winter months in northeastern Michigan. Current efforts to ban or control supplemental feeding of deer should have a positive effect on decreasing transmission of M. bovis among deer.

Mycobacterium bovis–Infected White-Tailed Deer (Odocoileus Virginianus): Detection of Immunoglobulin Specific to Crude Mycobacterial Antigens by ELISA

White-tailed deer (Odocoileus virginianus) have recently emerged as a source of Mycobacterium bovis infection for cattle within North America. The objective of this study was to evaluate the antibody response of M. bovis–infected deer to crude mycobacterial antigens. Deer were experimentally inoculated with M. bovis strain 1315 either by intratonsilar instillation or by exposure to M. bovis–infected (i.e., in contact) deer. To determine the time course of the response, including the effects of antigen administration for comparative cervical skin testing, serum was collected periodically and evaluated by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (i.e., IgG heavy and light chains) reactivity to mycobacterial antigens. The reactivity to M. bovis purified protein derivative (PPDb) exceeded (P < 0.05) the reactivity to M. avium PPD (PPDa) only after in vivo administration of PPDa and PPDb for comparative cervical testing of the infected deer. The mean immunoglobulin response, as measured by ELISA, of intratonsilar-inoculated deer to a proteinase K–digested whole-cell sonicate (WCS-PK) of M. bovis strain 1315 exceeded (P < 0.05) the mean of the prechallenge responses to this antigen at approximately 1 month after inoculation and throughout the remainder of the study (i.e., ~11 months). This response also exceeded (P < 0.05) that of the uninfected deer. Although this is encouraging, further studies are necessary to validate the use of the proteinase K–digested M. bovis antigens in the antibody-based assays of tuberculosis.

Vaccination with Mycobacterium bovis BCG Strains Danish and Pasteur in White-tailed Deer (Odocoileus virginianus) Experimentally Challenged with Mycobacterium bovis

Wildlife reservoirs of Mycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock and the cause for many faltering bovine tuberculosis eradication programs. One approach in dealing with wildlife reservoirs of disease is to interrupt inter-species and intraspecies transmission through vaccination of deer or cattle. To evaluate the efficacy of BCG vaccination in white-tailed deer, 35 deer were assigned to one of three groups; one s.c. dose of 107 CFU of M. bovis BCG Pasteur (n = 12); 1 s.c. dose of 107 CFU of M. bovis BCG Danish (n = 11); or unvaccinated deer (n = 12). After vaccination, deer were inoculated intratonsilarly with virulent M. bovis. Lesion severity scores of the medial retropharyngeal lymph node, as well as all lymph nodes combined, were reduced in vaccinated deer compared to unvaccinated deer. BCG Danish vaccinated deer had no late stage granulomas characterized by coalescent caseonecrotic granulomas containing numerous acid-fast bacilli compared to BCG Pasteur vaccinated or unvaccinated deer where such lesions were present. Both BCG strains were isolated as late as 250 days after vaccination from deer that were vaccinated but not challenged. In white-tailed deer, BCG provides protection against challenge with virulent M. bovis. Issues related to vaccine persistence, safety and shedding remain to be further investigated.