Comparison of current methods for the detection of chronic mycoplasmal urtd in wild populations of the mojave desert tortoise (Gopherus agassizii)

Franziska C. Sandmeier, Chava L. Weitzman, K. Nichole Maloney, C. Richard Tracy, Nathan C Nieto, Mike B. Teglas, Kenneth W. Hunter, Sally DuPré, C. M. Gienger, Michael W. Tuma

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Pathogens that cause subclinical diseases or exhibit low infection intensities are difficult to quantify in wild populations. Mojave desert tortoises (Gopherus agassizii) have been the focus of much research aimed at measuring the presence of upper respiratory disease (URTD) and URTD-associated pathogens, and techniques used to quantify disease in Gopherus species have also been used for disease surveillance in other species of turtles and tortoises of conservation concern. Published surveys of G. agassizii populations have found a relatively low prevalence of URTD, with most URTD-positive animals exhibiting moderate, intermittent signs of morbidity. Therefore, multiple tests have been developed to quantify URTD including genetic detection of the pathogens Mycoplasma agassizii and Mycoplasma testudineum, detection of M. agassizii-specific antibodies, and standardized quantification of clinical signs of URTD and body condition. These diagnostic tests have only been compared in diseased or moribund, semicaptive animals. We compared diagnostic techniques (TaqMant and SYBRe Green qPCR, serology, and visible examination) to detect M. agassizii-associated URTD in 126 wild desert tortoises sampled in Nevada and California, US in 2010. All had healthy body condition indices and none exhibited more than mild-to-moderate visual signs of URTD. Pairwise comparisons of diagnostic techniques indicated poor performance in diagnosing disease in individual animals. We found stronger, but inconsistent, statistical associations among diagnostic techniques at the population level. Our findings have implications for quantifying subclinical respiratory disease in tortoises.

Original languageEnglish (US)
Pages (from-to)91-101
Number of pages11
JournalJournal of Wildlife Diseases
Volume53
Issue number1
DOIs
StatePublished - Jan 1 2017

Fingerprint

Gopherus agassizii
Mojave Desert
respiratory disease
wild population
respiratory tract diseases
desert
Mycoplasma agassizii
diagnostic techniques
pathogen
tortoises
methodology
body condition
animal
Gopherus
microbial detection
tortoise
method
comparison
detection
animals

Keywords

  • Chelonian
  • Quantitative PCR
  • Reptile
  • Serology
  • Subclinical disease
  • SYBR Green
  • TaqMan

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology

Cite this

Comparison of current methods for the detection of chronic mycoplasmal urtd in wild populations of the mojave desert tortoise (Gopherus agassizii). / Sandmeier, Franziska C.; Weitzman, Chava L.; Maloney, K. Nichole; Tracy, C. Richard; Nieto, Nathan C; Teglas, Mike B.; Hunter, Kenneth W.; DuPré, Sally; Gienger, C. M.; Tuma, Michael W.

In: Journal of Wildlife Diseases, Vol. 53, No. 1, 01.01.2017, p. 91-101.

Research output: Contribution to journalArticle

Sandmeier, FC, Weitzman, CL, Maloney, KN, Tracy, CR, Nieto, NC, Teglas, MB, Hunter, KW, DuPré, S, Gienger, CM & Tuma, MW 2017, 'Comparison of current methods for the detection of chronic mycoplasmal urtd in wild populations of the mojave desert tortoise (Gopherus agassizii)', Journal of Wildlife Diseases, vol. 53, no. 1, pp. 91-101. https://doi.org/10.7589/2015-09-253
Sandmeier, Franziska C. ; Weitzman, Chava L. ; Maloney, K. Nichole ; Tracy, C. Richard ; Nieto, Nathan C ; Teglas, Mike B. ; Hunter, Kenneth W. ; DuPré, Sally ; Gienger, C. M. ; Tuma, Michael W. / Comparison of current methods for the detection of chronic mycoplasmal urtd in wild populations of the mojave desert tortoise (Gopherus agassizii). In: Journal of Wildlife Diseases. 2017 ; Vol. 53, No. 1. pp. 91-101.
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