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Elliott R Jacobson - One of the best experts on this subject based on the ideXlab platform.
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Serologic and molecular evidence for Testudinid herpesvirus 2 infection in wild Agassiz's desert Tortoises, Gopherus agassizii.
Journal of Wildlife Diseases, 2012Co-Authors: Elliott R Jacobson, Kristin H Berry, James F. X. Wellehan, April L. Childress, Francesco C. Origgi, Josephine Braun, Mark D. Schrenzel, Bruce A. RideoutAbstract:Following field observations of wild Agassiz's desert Tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive Tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert Tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert Tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and Tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of Tortoise 1 and from the tongue and nasal mucosa of Tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert Tortoise in California. Although several cases of herpesvirus infection have been des...
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Intranuclear coccidiosis in Tortoises: nine cases.
Veterinary Pathology, 2006Co-Authors: Michael M. Garner, James F. X. Wellehan, April L. Childress, Chris H. Gardiner, April J. Johnson, T. Mcnamara, M. Linn, Scott P. Terrell, Elliott R JacobsonAbstract:Chelonian intranuclear coccidiosis has been reported once, in two radiated Tortoises (Geochelone radiata), and is apparently rare. We describe intranuclear coccidiosis diagnosed histologically in two radiated Tortoises, three Travancore Tortoises (Indotestudo forstenii), two leopard Tortoises (Geochelone pardalis), one bowsprit Tortoise (Chersina angulata), and one impressed Tortoise (Manouria impressa). Infection was systemic and involved alimentary, urogenital, respiratory, lymphoid, endocrine, and integumentary systems. Trophozoites, meronts, merozoites, macrogametocytes, microgametocytes, and nonsporulated oocysts were seen histologically or by electron microscopy. Intracytoplasmic and extracellular stages of parasite development also were identified histologically. Sequencing of a coccidial 18S rRNA consensus polymerase chain reaction (PCR) product revealed a novel sequence that provided phylogenetic information and may be useful for further diagnostic test design. Intranuclear coccidiosis was associated with variable degrees of inflammation in all cases, was considered the cause of death in six Tortoises, and was a substantial contributing factor to the cause of death in two Tortoises.
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Experimental transmission of a herpesvirus in Greek Tortoises (Testudo graeca).
Veterinary Pathology, 2004Co-Authors: Francesco C. Origgi, Paul A. Klein, Carlos H. Romero, David C. Bloom, Jack M. Gaskin, Sylvia J. Tucker, Elliott R JacobsonAbstract:An experimental transmission study aimed at fulfilling Koch's postulates for a herpesvirus-as- sociated stomatitis-rhinitis in Mediterranean Tortoises is presented. Clinical, pathologic, serologic, and molecular studies were performed linking Tortoise herpesvirus with the pathogenesis of stomatitis-rhinitis. Four adult Greek Tortoises received either intranasally or intramuscularly two Tortoise herpesvirus isolates by primary experimental infection and secondary challenge 11 months later. After the primary experimental infection and the secondary challenge, clinical signs of illness developed, which included conjunctivitis, diphtheritic oral plaques, and oral discharge. At 4 weeks after the secondary challenge, all Tortoises were humanely euthanatized and evaluated. Although neutralizing antibodies developed after the primary experimental infection, they apparently did not prevent the later development of recurrent clinical signs. Polymerase chain reaction (PCR) and reverse tran- scription-PCR analyses allowed sensitive characterization of the systemic distribution of the herpesvirus DNA sequences and their presence in the cranial nerves and brains of the infected Tortoises. Despite the failure to recover the herpesviruses used in the transmission study, the findings support the premise that Tortoise herpes- virus is a primary pathogen of Greek Tortoises. A disease characterized by necrotizing stomatitis and rhinitis has been reported in several species of recently imported and captive Tortoises worldwide. This disease is particularly problematic in Greek (Tes- tudo graeca) and Hermann's (T. hermanni) Tortoises. Clinical signs range from mild conjunctivitis and clear nasal discharge to severe stomatitis and mucopurulent rhinitis. Signs of lower-respiratory tract and central nervous system (CNS) disease also have been seen. 7,22
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Enzyme-Linked Immunosorbent Assay for Detecting Herpesvirus Exposure in Mediterranean Tortoises (Spur-Thighed Tortoise [Testudo graeca] and Hermann's Tortoise [Testudo hermanni])
Journal of Clinical Microbiology, 2001Co-Authors: Francesco C. Origgi, Silvia Blahak, Paul A. Klein, Sylvia J. Tucker, K. Mathes, R. E. Marschang, Elliott R JacobsonAbstract:An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to a herpesvirus associated with an upper respiratory tract disease in Mediterranean Tortoises [spur-thighed Tortoise (Testudo graeca) and Hermann's Tortoise (Testudo hermanni)]. This serodiagnostic test was validated through a hyperimmunization study. The mean of the A(405) readings of the plasma samples collected at time zero of the hyperimmunization study plus three times the standard deviation was used as the cutoff for seropositivity in Tortoises. ELISA results were compared to serum neutralization (SN) values for the same samples by using the McNemar test. The results obtained by SN and ELISA were not significantly different (P > 0.05). This new ELISA could be used as an important diagnostic tool for screening wild populations and private and zoo collections of Mediterranean Tortoises.
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Diseases of the respiratory tract of chelonians.
Veterinary Clinics of North America: Exotic Animal Practice, 2000Co-Authors: Francesco Carlo Origgi, Elliott R JacobsonAbstract:Diseases of the respiratory tract commonly occur in captive chelonians, and several diseases also have occurred in wild chelonians. Infectious causes include viruses, bacteria, fungi, and parasites. Herpesviruses have surfaced as important pathogens of the oral cavity and respiratory tract in Hermann's Tortoise (Testudo her-manii), spur-thighed Tortoise (Testudo graeca), and other Tortoises in Europe and the United States. Herpes virus-associated respiratory diseases also have been reported in the green turtle, Chelonia mydas, in mariculture in the Cayman Islands. Of diseases caused by bacteria, an upper respiratory tract disease caused by Mycoplasma sp has been reported in free-hanging and captive gopher Tortoises in the southeastern United States and in desert Tortoises in the Mojave Desert of the southwestern United States. Mycotic pulmonary disease is commonly reported in captive chelonians, especially in those maintained at suboptimal temperatures. An intranuclear coccidia has been seen in several species of captive Tortoises in the United States, and, in one case, a severe proliferative pneumonia was associated with organisms in the lung. The most common noninfectious cause of respiratory disease in chelonians results from trauma to the carapace. Although pulmonary fibromas commonly occur in green turtles with fibropapillo-matosis, for the most part, tumors of the respiratory tract are uncommon in chelonians.
K. W. Hunter - One of the best experts on this subject based on the ideXlab platform.
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A quantitative PCR method for assessing the presence of Pasteurella testudinis DNA in nasal lavage samples from the desert Tortoise (Gopherus agassizii)
Journal of Microbiological Methods, 2012Co-Authors: S. A. Dupre', Franziska C Sandmeier, C R Tracy, K. W. HunterAbstract:Abstract Pasteurella testudinis has been associated with upper respiratory tract disease (URTD) in the threatened desert Tortoise ( Gopherus agassizii ). Our goal was to develop a sensitive and specific qPCR method for detecting DNA from P. testudinis in nasal lavage fluid collected from desert Tortoises in the field. Probes for 16S ribosomal RNA and RNA polymerase β-subunit (rpoB) genes were designed. A standard curve generated with DNA extracted from known numbers of bacterial cells determined by flow cytometry revealed a lower detection limit of 50 fg /ml (10 bacteria/ml). The nasal lavage fluid contained no interfering substances, and the qPCR method did not recognize normal flora DNA. The nasal lavage samples from 20 desert Tortoises captured in Clark County, Nevada, USA in 2007 and housed at the Desert Tortoise Conservation Center, were all positive for P. testudinis DNA by qPCR. Another set of 19 lavage samples collected in 2010 from wild desert Tortoises in the Mojave Desert were tested and 84% were positive for P. testudinis DNA. Fully validated, this qPCR method will provide a means of determining colonization rate. When used in conjunction with serological methods and clinical evaluations, both infection rate and disease rate can be determined for this potential URTD pathogen. This new assay provides an important tool for managing the threatened populations of the Mojave Desert Tortoise.
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quantitative pcr method for detection of mycoplasma spp dna in nasal lavage samples from the desert Tortoise gopherus agassizii
Journal of Microbiological Methods, 2011Co-Authors: S. A. Dupre', C R Tracy, K. W. HunterAbstract:Abstract Mycoplasma agassizii and M. testudineum have been associated with upper respiratory tract disease (URTD) in the threatened desert Tortoise ( Gopherus agassizii ). Because microbiological culture methods have proven difficult to employ in wild desert Tortoises, our goal was to develop a sensitive and specific qPCR method for detecting and quantifying mycoplasma DNA in nasal lavage fluid collected in the field. Primers for 16S ribosomal RNA gene sequences specific for M. agassizii and M. testudineum were designed, together with primers that recognize conserved sequences of both microorganisms. Standard curves generated with DNA extracted from known numbers of mycoplasma cells revealed a lower detection limit of approximately 5 fg. The qPCR method did not recognize normal flora DNA, and nasal lavage fluid contained no interfering substances. Nasal lavage samples collected from 20 captive desert Tortoises housed at the Desert Tortoise Conservation Center (Clark County, Nevada, USA) revealed the presence of M. agassizii DNA in 100% of the Tortoises. Concentrations ranged from a low of 6 pg ml − 1 to a high of 72,962 pg ml − 1 . Only one of the Tortoises was positive for M. testudineum . Interestingly, not all of the qPCR positive Tortoises showed evidence of seroconversion, suggesting that they were colonized but not infected. This new quantitative method will provide a critical tool for managing threatened populations of the desert Tortoise.
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upper respiratory tract disease urtd as a threat to desert Tortoise populations a reevaluation
Biological Conservation, 2009Co-Authors: Franziska C Sandmeier, S. A. Dupre', Richard C Tracy, K. W. HunterAbstract:The relationships between Mycoplasma agassizii, a causative agent of upper respiratory disease (URTD), and desert Tortoise (Gopherus agassizii), generally illustrate the complexities of disease dynamics in wild vertebrate populations. In this review, we summarize current understanding of URTD in Mojave desert Tortoise populations, we illustrate how inadequate knowledge of Tortoise immune systems may obfuscate assessment of disease, and we suggest approaches to future management of URTD in desert Tortoise populations. We challenge the view that M. agassizii causes consistent levels of morbidity and/or mortality across the Mojave desert. Instead, URTD may be described more accurately as a context-dependent disease. In addition, new evidence for relatively high levels of natural antibodies to M. agassizii in desert Tortoises suggests possible problems in conventional diagnostic tests of disease in Tortoises as well as a possible Tortoise immune mechanism to protect against M. agassizii. Partly because of the problems in diagnostic testing, we recommend abandoning policies to euthanize Tortoises that test positive for an immune response to M. agassizii. Based on this review, we question management strategies aimed solely at reducing Mycoplasma spp. in desert Tortoise populations, and advocate a more careful consideration of extrinsic factors as a cause of symptomatic disease.
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western blot can distinguish natural and acquired antibodies to mycoplasma agassizii in the desert Tortoise gopherus agassizii
Journal of Microbiological Methods, 2008Co-Authors: K. W. Hunter, S. A. Dupre', Franziska C Sandmeier, Tiffanny Sharp, Richard C TracyAbstract:Mycoplasma agassizi has been identified as a cause of upper respiratory tract disease (URTD) in the threatened Mojave population of the desert Tortoise (Gopherus agassizii), and anti-M. agassizii antibodies have been found by ELISA in as many as 15% of these animals across their geographic range. Here we report that a cohort of 16 egg-reared desert Tortoises never exposed to M. agassizii had ELISA antibody titers to this organism that overlapped with titers obtained from some M. agassizii-infected Tortoises. These natural antibodies were predominantly of the IgM class. Western blots of plasma from these non-infected Tortoises produced a characteristic banding pattern against M. agassizii antigens. A group of 38 wild-caught desert Tortoises was tested by ELISA, and although some of these Tortoises had antibody titers significantly higher than the non-infected Tortoises, there was considerable overlap at the lower titer levels. However, Western blot analysis revealed distinct banding patterns that could readily distinguish between the non-infected Tortoises and Tortoises with acquired antibodies, regardless of ELISA antibody titers. We conclude that desert Tortoises have natural antibodies to M. agassizii that can compromise the determination of infection status by ELISA. However, the Western blot technique can distinguish between natural and acquired antibody patterns and can be used to confirm the diagnosis of M. agassizii infections in the desert Tortoise.
El Hassan El Mouden - One of the best experts on this subject based on the ideXlab platform.
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Absence of Hemolivia mauritanica (Apicomplexa: Haemogregarinidae) in natural populations of Testudo graeca in Morocco
Parasitology Research, 2020Co-Authors: El-mustapha Laghzaoui, Dimitra Sergiadou, Ana Perera, D. James Harris, Abdelaziz Abbad, El Hassan El MoudenAbstract:During spring 2018, we captured 101 spur-thighed Tortoises, Testudo graeca, from seven localities in central Morocco. All Tortoises were examined for the presence of blood parasites Hemolivia mauritanica and Hyalomma aegyptium ticks, the known vectors. We looked for H. mauritanica infection by examination of blood smears and by genetic analysis with PCR using extractions from both Tortoises and ticks. On all Tortoises collected, 71.29% were infested with at least one tick, with a mean infestation intensity of 7.12 ticks/Tortoise and maximum of 15.55 ticks/Tortoises in Had Draa locality (Essaouira region). Although the definitive host is present and abundant in all Tortoise populations, all blood samples were Hemolivia -negative. Our results support and confirm the finding of studies previously conducted in other populations of Morocco and indicate that H. mauritanica has a narrower distribution range than its tick vector.
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Absence of Hemolivia mauritanica (Apicomplexa: Haemogregarinidae) in natural populations of Testudo graeca in Morocco
Parasitology Research, 2020Co-Authors: El-mustapha Laghzaoui, Dimitra Sergiadou, Ana Perera, D. James Harris, Abdelaziz Abbad, El Hassan El MoudenAbstract:During spring 2018, we captured 101 spur-thighed Tortoises, Testudo graeca, from seven localities in central Morocco. All Tortoises were examined for the presence of blood parasites Hemolivia mauritanica and Hyalomma aegyptium ticks, the known vectors. We looked for H. mauritanica infection by examination of blood smears and by genetic analysis with PCR using extractions from both Tortoises and ticks. On all Tortoises collected, 71.29% were infested with at least one tick, with a mean infestation intensity of 7.12 ticks/Tortoise and maximum of 15.55 ticks/Tortoises in Had Draa locality (Essaouira region). Although the definitive host is present and abundant in all Tortoise populations, all blood samples were Hemolivia -negative. Our results support and confirm the finding of studies previously conducted in other populations of Morocco and indicate that H. mauritanica has a narrower distribution range than its tick vector.
Franziska C Sandmeier - One of the best experts on this subject based on the ideXlab platform.
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Prevalence and Diversity of the Upper Respiratory Pathogen Mycoplasma agassizii in Mojave Desert Tortoises (Gopherus agassizii)
Herpetologica, 2017Co-Authors: Chava L. Weitzman, Franziska C Sandmeier, C. Richard TracyAbstract:Abstract: Upper respiratory tract disease (URTD), caused by Mycoplasma agassizii, has been deemed a threat to populations of Mojave Desert Tortoises, Gopherus agassizii. Previous work on URTD has focused on serology and visual health examinations to determine the extent of this disease in some natural Tortoise populations. Here, we present the first range-wide study of the presence of the pathogen, M. agassizii, in Mojave Desert Tortoises. We detected M. agassizii in Tortoise populations throughout the Mojave Desert, with notable differences in prevalence of M. agassizii among sampling sites within Tortoise genotypes and sampling years. Analyses of three genetic markers in the M. agassizii genome indicated very low nucleotide diversity and no relevant spatial structuring of Mycoplasma haplotypes. We use published lines of evidence to discuss the roles of rare transmission events and long-term mycoplasmal persistence in individual hosts on Tortoise URTD dynamics.
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A quantitative PCR method for assessing the presence of Pasteurella testudinis DNA in nasal lavage samples from the desert Tortoise (Gopherus agassizii)
Journal of Microbiological Methods, 2012Co-Authors: S. A. Dupre', Franziska C Sandmeier, C R Tracy, K. W. HunterAbstract:Abstract Pasteurella testudinis has been associated with upper respiratory tract disease (URTD) in the threatened desert Tortoise ( Gopherus agassizii ). Our goal was to develop a sensitive and specific qPCR method for detecting DNA from P. testudinis in nasal lavage fluid collected from desert Tortoises in the field. Probes for 16S ribosomal RNA and RNA polymerase β-subunit (rpoB) genes were designed. A standard curve generated with DNA extracted from known numbers of bacterial cells determined by flow cytometry revealed a lower detection limit of 50 fg /ml (10 bacteria/ml). The nasal lavage fluid contained no interfering substances, and the qPCR method did not recognize normal flora DNA. The nasal lavage samples from 20 desert Tortoises captured in Clark County, Nevada, USA in 2007 and housed at the Desert Tortoise Conservation Center, were all positive for P. testudinis DNA by qPCR. Another set of 19 lavage samples collected in 2010 from wild desert Tortoises in the Mojave Desert were tested and 84% were positive for P. testudinis DNA. Fully validated, this qPCR method will provide a means of determining colonization rate. When used in conjunction with serological methods and clinical evaluations, both infection rate and disease rate can be determined for this potential URTD pathogen. This new assay provides an important tool for managing the threatened populations of the Mojave Desert Tortoise.
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upper respiratory tract disease urtd as a threat to desert Tortoise populations a reevaluation
Biological Conservation, 2009Co-Authors: Franziska C Sandmeier, S. A. Dupre', Richard C Tracy, K. W. HunterAbstract:The relationships between Mycoplasma agassizii, a causative agent of upper respiratory disease (URTD), and desert Tortoise (Gopherus agassizii), generally illustrate the complexities of disease dynamics in wild vertebrate populations. In this review, we summarize current understanding of URTD in Mojave desert Tortoise populations, we illustrate how inadequate knowledge of Tortoise immune systems may obfuscate assessment of disease, and we suggest approaches to future management of URTD in desert Tortoise populations. We challenge the view that M. agassizii causes consistent levels of morbidity and/or mortality across the Mojave desert. Instead, URTD may be described more accurately as a context-dependent disease. In addition, new evidence for relatively high levels of natural antibodies to M. agassizii in desert Tortoises suggests possible problems in conventional diagnostic tests of disease in Tortoises as well as a possible Tortoise immune mechanism to protect against M. agassizii. Partly because of the problems in diagnostic testing, we recommend abandoning policies to euthanize Tortoises that test positive for an immune response to M. agassizii. Based on this review, we question management strategies aimed solely at reducing Mycoplasma spp. in desert Tortoise populations, and advocate a more careful consideration of extrinsic factors as a cause of symptomatic disease.
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western blot can distinguish natural and acquired antibodies to mycoplasma agassizii in the desert Tortoise gopherus agassizii
Journal of Microbiological Methods, 2008Co-Authors: K. W. Hunter, S. A. Dupre', Franziska C Sandmeier, Tiffanny Sharp, Richard C TracyAbstract:Mycoplasma agassizi has been identified as a cause of upper respiratory tract disease (URTD) in the threatened Mojave population of the desert Tortoise (Gopherus agassizii), and anti-M. agassizii antibodies have been found by ELISA in as many as 15% of these animals across their geographic range. Here we report that a cohort of 16 egg-reared desert Tortoises never exposed to M. agassizii had ELISA antibody titers to this organism that overlapped with titers obtained from some M. agassizii-infected Tortoises. These natural antibodies were predominantly of the IgM class. Western blots of plasma from these non-infected Tortoises produced a characteristic banding pattern against M. agassizii antigens. A group of 38 wild-caught desert Tortoises was tested by ELISA, and although some of these Tortoises had antibody titers significantly higher than the non-infected Tortoises, there was considerable overlap at the lower titer levels. However, Western blot analysis revealed distinct banding patterns that could readily distinguish between the non-infected Tortoises and Tortoises with acquired antibodies, regardless of ELISA antibody titers. We conclude that desert Tortoises have natural antibodies to M. agassizii that can compromise the determination of infection status by ELISA. However, the Western blot technique can distinguish between natural and acquired antibody patterns and can be used to confirm the diagnosis of M. agassizii infections in the desert Tortoise.
Richard C Tracy - One of the best experts on this subject based on the ideXlab platform.
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upper respiratory tract disease urtd as a threat to desert Tortoise populations a reevaluation
Biological Conservation, 2009Co-Authors: Franziska C Sandmeier, S. A. Dupre', Richard C Tracy, K. W. HunterAbstract:The relationships between Mycoplasma agassizii, a causative agent of upper respiratory disease (URTD), and desert Tortoise (Gopherus agassizii), generally illustrate the complexities of disease dynamics in wild vertebrate populations. In this review, we summarize current understanding of URTD in Mojave desert Tortoise populations, we illustrate how inadequate knowledge of Tortoise immune systems may obfuscate assessment of disease, and we suggest approaches to future management of URTD in desert Tortoise populations. We challenge the view that M. agassizii causes consistent levels of morbidity and/or mortality across the Mojave desert. Instead, URTD may be described more accurately as a context-dependent disease. In addition, new evidence for relatively high levels of natural antibodies to M. agassizii in desert Tortoises suggests possible problems in conventional diagnostic tests of disease in Tortoises as well as a possible Tortoise immune mechanism to protect against M. agassizii. Partly because of the problems in diagnostic testing, we recommend abandoning policies to euthanize Tortoises that test positive for an immune response to M. agassizii. Based on this review, we question management strategies aimed solely at reducing Mycoplasma spp. in desert Tortoise populations, and advocate a more careful consideration of extrinsic factors as a cause of symptomatic disease.
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western blot can distinguish natural and acquired antibodies to mycoplasma agassizii in the desert Tortoise gopherus agassizii
Journal of Microbiological Methods, 2008Co-Authors: K. W. Hunter, S. A. Dupre', Franziska C Sandmeier, Tiffanny Sharp, Richard C TracyAbstract:Mycoplasma agassizi has been identified as a cause of upper respiratory tract disease (URTD) in the threatened Mojave population of the desert Tortoise (Gopherus agassizii), and anti-M. agassizii antibodies have been found by ELISA in as many as 15% of these animals across their geographic range. Here we report that a cohort of 16 egg-reared desert Tortoises never exposed to M. agassizii had ELISA antibody titers to this organism that overlapped with titers obtained from some M. agassizii-infected Tortoises. These natural antibodies were predominantly of the IgM class. Western blots of plasma from these non-infected Tortoises produced a characteristic banding pattern against M. agassizii antigens. A group of 38 wild-caught desert Tortoises was tested by ELISA, and although some of these Tortoises had antibody titers significantly higher than the non-infected Tortoises, there was considerable overlap at the lower titer levels. However, Western blot analysis revealed distinct banding patterns that could readily distinguish between the non-infected Tortoises and Tortoises with acquired antibodies, regardless of ELISA antibody titers. We conclude that desert Tortoises have natural antibodies to M. agassizii that can compromise the determination of infection status by ELISA. However, the Western blot technique can distinguish between natural and acquired antibody patterns and can be used to confirm the diagnosis of M. agassizii infections in the desert Tortoise.
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can modeling improve estimation of desert Tortoise population densities
Ecological Applications, 2007Co-Authors: Kenneth E Nussear, Richard C TracyAbstract:The federally listed desert Tortoise (Gopherus agassizii) is currently monitored using distance sampling to estimate population densities. Distance sampling, as with many other techniques for estimating population density, assumes that it is possible to quantify the proportion of animals available to be counted in any census. Because desert Tortoises spend much of their life in burrows, and the proportion of Tortoises in burrows at any time can be extremely variable, this assumption is difficult to meet. This proportion of animals available to be counted is used as a correction factor (g0) in distance sampling and has been estimated from daily censuses of small populations of Tortoises (6-12 individuals). These censuses are costly and produce imprecise estimates of g0 due to small sample sizes. We used data on Tortoise activity from a large (N = 1 50) experimental population to model activity as a function of the biophysical attributes of the environment, but these models did not improve the precision of estimates from the focal populations. Thus, to evaluate how much of the variance in Tortoise activity is apparently not predictable, we assessed whether activity on any particular day can predict activity on subsequent days with essentially identical environmental conditions. Tortoise activity was only weakly correlated on consecutive days, indicating that behavior was not repeatable or consistent among days with similar physical environments.
