Mycoplasmosis in Free-ranging Desert Tortoises in Utah and Arizona

Dickinson, Vanessa M.; Schumacher, Isabella M.; Jarchow, James L.; Duck, Timothy; Schwalbe, Cecil R.

doi:10.7589/0090-3558-41.4.839

Cited by 16 publications

(2 citation statements)

References 8 publications

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“…The differences noted in detection rates between wild reptiles and reptiles in captivity could—as mentioned above—also be due to differences in conditions, with dietary, stress and crowding-related factors likely causing the higher detection rates found in reptiles in captivity. Given the high dependency of ectothermic organisms on their environment, and natural living situations probably reflecting more physiological conditions than those in captivity, this could contribute to a stronger immune system and reduced stress ( DuPonte et al, 1978 ; Geue and Löschner, 2002 ; Dickinson et al, 2005 ; Scheelings et al, 2011 ; Cota et al, 2021 ).…”

Section: Discussionmentioning

confidence: 99%

Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections

Pees,

Brockmann,

Steiner

et al. 2023

Front. Cell Dev. Biol.

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Salmonella are considered a part of the normal reptile gut microbiota, but have also been associated with disease in reptiles. Reptile-associated salmonellosis (RAS) can pose a serious health threat to humans, especially children, and an estimated 6% of human sporadic salmonellosis cases have been attributed to direct or indirect contact with reptiles, although the exact number is not known. Two literature searches were conducted for this review. The first evaluated reports of the prevalence of Salmonella in the intestinal tracts of healthy reptiles. Salmonella were most commonly detected in snakes (56.0% overall), followed by lizards (36.9%) and tortoises (34.2%), with lower detection rates reported for turtles (18.6%) and crocodilians (9%). Reptiles in captivity were significantly more likely to shed Salmonella than those sampled in the wild. The majority of Salmonella strains described in reptiles belonged to subspecies I (70.3%), followed by subspecies IIIb (29.7%) and subspecies II (19.6%). The second literature search focused on reports of RAS, revealing that the highest number of cases was associated with contact with turtles (35.3%), followed by lizards (27.1%) and snakes (20.0%). Reptiles associated with RAS therefore did not directly reflect prevalence of Salmonella reported in healthy representatives of a given reptile group. Clinical symptoms associated with RAS predominantly involved the gastrointestinal tract, but also included fever, central nervous symptoms, problems with circulation, respiratory symptoms and others. Disease caused by Salmonella in reptiles appears to be dependent on additional factors, including stress, inadequate husbandry and hygiene, and other infectious agents. While it has been suggested that reptile serovars may cause more severe disease than human-derived strains, and some data is available on invasiveness of individual strains in cell culture, limited information is available on potential mechanisms influencing invasiveness and immune evasion in reptiles and in RAS. Strategies to mitigate the spread of Salmonella through reptiles and to reduce RAS focus mostly on education and hygiene, and have often been met with some success, but additional efforts are needed. Many aspects regarding Salmonella in reptiles remain poorly understood, including the mechanisms by which Salmonella persist in reptile hosts without causing disease.

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Section: Discussionmentioning

confidence: 99%

Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections

Pees,

Brockmann,

Steiner

et al. 2023

Front. Cell Dev. Biol.

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“…The Sonoran Desert tortoise does not appear to face the health-related effects of upper respiratory tract disease observed in Mojave desert tortoise caused by infectious bacterium Mycoplasma agassizii [10], perhaps resulting from some inherently different immunological response, lower frequency of encountering the pathogen, or healthier populations due to higher genetic diversity and census size [11][12][13]. There is limited information about other pathogens infecting the tortoise family Testudinidae.…”

Section: Introductionmentioning

confidence: 99%

Virus Discovery in Desert Tortoise Fecal Samples: Novel Circular Single-Stranded DNA Viruses

Orton

Morales

Fontenele

et al. 2020

Viruses

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The Sonoran Desert tortoise Gopherus morafkai is adapted to the desert, and plays an important ecological role in this environment. There is limited information on the viral diversity associated with tortoises (family Testudinidae), and to date no DNA virus has been identified associated with these animals. This study aimed to assess the diversity of DNA viruses associated with the Sonoran Desert tortoise by sampling their fecal matter. A viral metagenomics approach was used to identify the DNA viruses in fecal samples from wild Sonoran Desert tortoises in Arizona, USA. In total, 156 novel single-stranded DNA viruses were identified from 40 fecal samples. Those belonged to two known viral families, the Genomoviridae (n = 27) and Microviridae (n = 119). In addition, 10 genomes were recovered that belong to the unclassified group of circular-replication associated protein encoding single-stranded (CRESS) DNA virus and five circular molecules encoding viral-like proteins.

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Distance to human populations influences epidemiology of respiratory disease in desert tortoises

et al. 2014

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We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km 2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/ or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of testpositive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of humanpopulated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

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Mycoplasmosis in Free-ranging Desert Tortoises in Utah and Arizona

Cited by 16 publications

References 8 publications

Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections

Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections

Virus Discovery in Desert Tortoise Fecal Samples: Novel Circular Single-Stranded DNA Viruses

Distance to human populations influences epidemiology of respiratory disease in desert tortoises

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