Pneumonia in a Captive Central Bearded Dragon With Concurrent Detection of Helodermatid Adenovirus 2 and a Novel Mycoplasma Species

Abstract

A 4-year-old captive male central bearded dragon ( Pogona vitticeps) was presented for recurrent episodic dyspnea and anorexia with occasional expulsion of oral mucoid discharge. Despite empirical antimicrobial therapy and supportive care, the animal died and was submitted for autopsy. Defining histologic features included heterophilic and lymphocytic interstitial pneumonia, with occasional amphophilic intranuclear inclusions and prominent type II pneumocyte hyperplasia. Transmission electron microscopy revealed intranuclear 80-nm, nonenveloped, hexagonal viral particles within pneumocytes. Helodermatid adenovirus 2 (HeAdV2) was determined as the etiologic agent through pan-adenoviral consensus polymerase (PCR) chain reaction and sequencing. Nucleic acid from a novel Mycoplasma sp. (provisionally called Mycoplasma pogonae) was identified by pan-generic PCR targeting the mycoplasma 16S ribosomal RNA gene with sequencing and phylogenetic analysis. As bacteria morphologically consistent with Mycoplasma sp. were not observed by special stains and transmission electron microscopy, the detection of M. pogonae nucleic acid is of indeterminate significance; however, M. pogonae and HeAdV2 coinfection may have exacerbated disease.