Editorial Type:
Article Category: Brief Report
 | 
Online Publication Date: 17 Jun 2022

Mycobacterial Cloacitis with Systemic Dissemination in a Hermann's Tortoise (Testudo hermanni)

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Page Range: 162 – 170
DOI: 10.5818/JHMS-D-21-00033
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Abstract

In recent years, many nontuberculous mycobacteria (NTM) species have been recognized as pathogens for humans and animals. Molecular diagnostic techniques enable rapid identification and characterization of the different species of mycobacteria. NTM are inhabitants of the soil and water, and enter the body through a defect in the skin or mucosa, causing infections in immunocompromised subjects. Mycobacteriosis has been described in reptiles, especially in chelonians, but the incidence seems to be low in captivity. To date, mycobacteriosis has been described only in three tortoise species. This report involves a captive Hermann's tortoise (Testudo hermanni) diagnosed with cloacal mycobacteriosis and subsequent systemic dissemination by histopathology and PCR. A Mycobacterium sp. belonging to the M. terrae complex was identified as the etiologic agent, and this is the first report of infection in reptiles by this organism.

Keywords: Granulomatous cloacitis; granulomatous hepatitis; Hermann's tortoise; Mycobacterium terrae complex; Testudo hermanni
Figure 1.
Figure 1.

Swollen tail and cloaca of the Hermann's tortoise (Testudo hermanni), with deep mucosal ulcerations and necrotic areas on the muco-cutaneous junction.

Figure 2.
Figure 2.

Deep ulceration of the skin after removing the caseous material over the left knee of the Hermann's tortoise (Testudo hermanni).

Figure 3.
Figure 3.

White granulomas in the mesentery of the Hermann's tortoise (Testudo hermanni) found during the postmortem.

Figure 4.
Figure 4.

Histological image of the lesion in the cloacal mucosa of the Hermann's tortoise (Testudo hernmanni). Note extensive ulceration of the cloacal mucosa (delimited with arrowheads), which is covered by a thick necrosuppurative exudate (asterisks). Unaffected cloacal mucosa is present at the advancing edge of the lesion (arrow). Hematoxylin and eosin; × 4.4.

Figure 5.
Figure 5.

Histological image of the adrenal gland of the Hermann's tortoise (Testudo hermanni). Note the presence of a large granulomatous and necroheterophilic lesion (arrowheads) effacing the adrenal gland (a), with fibrin deposits (arrow) and fibrosis extending into and compressing the renal vein wall (v). k = kidney. Hematoxylin and eosin; × 4.4.

Figure 6.
Figure 6.

Histological image of the liver of the Hermann's tortoise (Testudo hermanni). A granuloma (arrows) with a small necrotic center is partly surrounded by fibrin deposits (f) and mild fibrosis in the hepatic parenchyma. Hepatocytes are atrophic. Hematoxylin and eosin, × 22.

Figure 7.
Figure 7.

Histological image of the adrenal gland of the Hermann's tortoise (Testudo hermanni). Acid-fast bacilli are present in the granulomatous lesion. Ziehl-Neelsen stain; × 120.

Figure 8.
Figure 8.

Neighbor-joining phylogenetic trees for 16S rRNA (a) and rpoB (b). The percentages of replicate trees in which the associated taxa clustered together according to the bootstrap (1,000 replicates) are shown next to the branches. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the Kimura two-parameter method as number of base substitutions per site. Mycobacterium tuberculosis was used as an outgroup/root. Sequence accession numbers are given in parentheses. The mycobacterial isolate identified in this study is highlighted by a black circle.

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