DETECTION OF COPATHOGENS IN FREE-RANGING EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) IN ILLINOIS AND TENNESSEE

Abstract

Conservation efforts are investigating the impact of diseases within a species of interest, including prevalence and transmission and morbidity and mortality rates. However, the majority of these studies focus solely on the characteristics of a single pathogen. Recently, the role of copathogens has been reported to impact disease susceptibility and mortality. To that effect, a survey was conducted including 318 eastern box turtles ( Terrapene carolina carolina) from populations in Illinois and Tennessee in 2014 and 2015. Blood samples and oral swabs were collected for quantitative polymerase chain reaction (qPCR) of 15 different pathogens performed in a multiplex format using Fluidigm array technology. Four pathogens were found with varying qPCR prevalence: ranavirus (FV3; n = 2, 0.6%), Terrapene herpesvirus 1 (TerHV1; n = 129, 40.7%), box turtle Mycoplasma sp. (BT Myco; n = 14, 4.6%), and box turtle adenovirus (BT Adv1; n = 18, 11%). Thirteen pathogens were not identified in any sample, including Mycoplasma agassizii, M. testudineum, Salmonella enteriditis, S. typhmirium, Borrelia burgdorferi, Anaplasma phagocyophilum, tortoise intranuclear coccidia, Ambystoma tigrinum virus, Bohle iridovirus, Epizootic hematopoietic necrosis virus, and testudinid herpesvirus 2. Copathogen occurrence was rare but was observed in eight individuals with TerHV1-BT Myco detection and two animals with TerHV1-Adv1. Significant differences were observed in pathogen detection across season (TerHV1, BT Adv1, BT Myco, and TerHV1-Myco) and year (TerHV1, BT Adv1, and TerHV1-Myco). The results of this survey highlight that a single pathogen model may not adequately explain pathogen dynamics and that conservation efforts need to be aimed at detecting multiple pathogens in order to fully characterize population health.

Ranaviruses and reptiles

“…Following this, ranaviruses were predominantly isolated from box turtles ( Terrapene carolina ) and were identified as the aetiological agent of ‘red neck disease’ in the soft-shelled turtle ( Pelodiscus sinensis ) (Chen, Zheng & Jiang, 1999). In the last decade, several new reports of ranaviral infections in Testudines have been published (Johnson et al, 2008; Johnson et al, 2010; Belzer & Seibert, 2011; Allender, 2012; Stöhr et al., 2015; Perpiñán et al, 2016; Butkus et al, 2017; Agha et al, 2017; Archer et al, 2017; Adamovicz et al, 2018). Despite the increasing number of reports of infections in the Testudines, ranaviral disease in these reptiles is still likely to be underreported due to a lack of awareness, an incomplete understanding of the pathology caused by the disease, few long-term studies, and minimal population monitoring (Duffus et al, 2015).…”

“…Reptilian hosts of ranaviruses experience a range of histological changes including necrosis and inflammation of the respiratory tract, pneumonia, conjunctivitis, stomatitis, esophagitis, tracheitis, necrosis of endothelial cells and the submucosa of the gastrointestinal tract, glomerulonephritis, multifocal hepatic necrosis, splenitis, intracytoplasmic inclusion bodies in many tissues, and necrotizing myositis (see Table 1). Evidence from epizootics in reptiles indicates that ranaviral infection can be accompanied by secondary pathogens that may exacerbate the disease and mask clinical signs of ranaviral infection (Stohr et al, 2013; Sim et al, 2016; Archer et al, 2017).…”

Erythrocyte sedimentation rate and hemoglobin-binding protein in free-living box turtles (Terrapene spp.)

“…ranavirus, Mycoplasma sp., herpesviruses, adenovirus) and toxicants (e.g. organochlorines, heavy metals); underscoring the need for reliable tools to characterize emerging health threats [29][30][31][32][33][34][35][36][37][38][39][40]. Acute phase response testing in box turtles may supplement existing diagnostic modalities and improve health assessment protocols; ultimately supporting conservation goals and enhancing the evaluation of ecosystem wellness [41].…”

Adenoviruses in free-ranging Australian bearded dragons (Pogona spp.)

“…Other authors have also described the detection of adenoviruses by PCR in free-ranging reptiles. Adenoviruses have twice been detected in freeranging eastern box turtles (Terrapene carolina carolina) from Illinois and Tennessee (Archer et al, 2017;Adamovicz et al, 2018). They have also been detected in lizards from Spain and islands north of Africa (Szirovicza et al, 2016) and Gila monsters (Heloderma (Benge et al, 2019).…”