Oral, Cloacal, and Hemipenal Actinomycosis in Captive Ball Pythons (Python regius)

Abstract

Ball pythons (Python regius) are one of the most commonly kept and bred reptiles in captivity. In a large ball python breeding colony, a unique syndrome characterized by granulomatous inflammation of the cloaca and hemipenes (phalli) was observed in 140 of 481 (29.1%) breeding males, but only one of 1,446 breeding females. Lesions were absent in virgin males (n = 201) and virgin females (n = 293). On postmortem examination (n = 13, 12 males, 1 female), numerous well-defined mucosal and submucosal granulomas were present in the hemipenes (males) and cloaca (males and female). Extension into the coelomic cavity and liver was noted in a subset of these animals. An additional small subset of breeder animals (6/2027; 0.3%) presented with oral and mandibular swellings. Postmortem examination (n = 4, all female) showed oral lesions histologically indistinguishable from the cloacal/hemipenal lesions. Aerobic bacterial culture of a hepatic granuloma of one snake resulted in the isolation of filamentous, Gram-positive bacilli; amplification, and sequencing of the 16S rRNA gene and subsequent phylogenetic analysis of the isolate identified the bacterium as a novel species of Actinomyces. Screening of cloacal and oral granulomas using a specific, heminested 16S rRNA PCR assay confirmed the presence of the agent in all 17 snakes, as well as in cloacal swabs taken at the time of necropsy in 11/13 snakes. The Actinomyces sp. was also identified by PCR of cloacal swabs of unaffected snakes (n = 94) from the affected colony and two unrelated, grossly unaffected breeding colonies. In the affected colony, 65.5% of breeding animals (n = 23) but only 11.9% of virgin animals (n = 42) tested PCR positive, with breeding status being a significant predictor of bacterium presence (P < 0.00001). This study characterizes a granulomatous mucosal disease syndrome of breeding male ball pythons associated with a novel Actinomyces. In stark contrast to male snakes, the presence of the bacterium in both breeding and virgin females was very rarely associated with clinical disease. Though additional studies are necessary, these data suggest a role for the novel bacterium in the disease process, a predilection for clinical disease in male snakes, and the potential for sexual transmission of the disease.

Increased host diversity limits bacterial generalism but may promote microbe-microbe interactions

“…Cloacal microbiota composition can be impacted by host diet, habitat and stress levels (Colston 2017; Ambrosini et al 2019; Van Veelen et al 2020). These communities can include parasites that lead to morbidity or mortality (Johne et al 2002; Styles et al 2004; Curtiss et al 2015; Tillis et al 2021), exerting selective pressure on hosts. The cloaca also houses microbial lineages that inoculate the eggshell during laying and provide protection against fungal infection, another source of selection on host control of the microbiome (Bunker et al 2021).…”

Phylogenetically under‐dispersed gut microbiomes are not correlated with host genomic heterozygosity in a genetically diverse reptile community

“…The cloacal microbiome is distinct from the lower gut and faecal microbiome, with some studies finding little correlation between the communities (Kers et al, 2019; Lee et al, 2020; Williams & Athrey, 2020), while others do find similarities (Andreani et al, 2020; Berlow et al, 2020; Bodawatta et al, 2020; Zhou et al, 2020). The cloacal mucosa is integral to health in reptiles, with a variety of pathogens causing symptomatic infection in the area (Curtiss et al, 2015; Johne et al, 2002; Styles et al, 2004; Tillis et al, 2021). In addition, the cloacal microbiome in lizards seeds eggshells with antifungal microbial lineages, a key fitness benefit (Bunker et al, 2021).…”

Proliferative strongyloidiasis in a colony of colubrid snakes

“…28 As with other animal production sectors, intensive production of reptiles can be associated with challenges, including disease outbreak and control. 25,31,32 Parasitic disease is important in captive reptile collections due to the frequency with which infections may go undetected and the effects that heavy parasitism can have on animal health. 5,43 Strongyloides spp nematodes, colloquially known as threadworms, are members of the order Rhabditida.…”