Pulmonary fungal granulomas and fibrinous pneumonia caused by different hypocrealean fungi in reptiles

Vet Microbiol. 2018 Nov:225:58-63. doi: 10.1016/j.vetmic.2018.09.008. Epub 2018 Sep 19.

Abstract

In contrast to fungal dermatitis, fungal glossitis and disseminated visceral mycosis, fungal infection of the lung has so far rarely been described in reptiles. Pulmonary fungal granulomas were diagnosed histopathologically within the scope of post mortem examinations. Fragments of the 18S-internal transcribed spacer1-5.8S rDNA (SSU-ITS1-5.8S) and 28S rDNA (LSU), including domains (D)1 and D2 as well as the protein coding gene translation elongation factor 1 alpha (TEF) were used for phylogenetical analysis after isolation of the fungal pathogen by culturing. Ten reptiles, including lizards (n = 6), snakes (n = 1), crocodilians (n = 2) and tortoises (n = 1) presented with pulmonary fungal granulomas (n = 8) and fibrinous pneumonia (n = 2) caused by different non-clavicipitaceous and clavicipitaceous species of the order Hypocreales. Purpureocillium lavendulum (n = 2) and Metarhizium robertsii (n = 1) as the etiologic agents of pneumonia in reptile species are described for the first time. Fungal pulmonary granulomas caused by clavicipitaceous fungi (n = 6) were all associated with disseminated visceral mycosis as well as oral fungal granulomas (n = 4) and/or fungal dermatitis (n = 1). Differing infection routes being likely for clavicipitaceous and non-clavicipitaceous fungal pathogens. A potential zoonotic health risk should be taken into account during necropsy or lung sampling in live reptiles with pulmonary fungal granulomas, since human infections, mainly keratitis and sclerokeratitis, caused by Beauveria bassiana, Metarhizium robertsii and Purpureocillium lilacinum, have occasionally been described.

Keywords: Beauveria bassiana; Clavicipitaceae; Crocodiles; Lizards; Metarhizium; Pneumonia; Purpureocillium lavendulum; Python.

MeSH terms

  • Alligators and Crocodiles / microbiology
  • Animals
  • Beauveria / genetics
  • Beauveria / isolation & purification
  • Boidae / microbiology
  • DNA, Ribosomal / genetics
  • Fibrin*
  • Granuloma / diagnosis
  • Granuloma / microbiology*
  • Granuloma / pathology
  • Humans
  • Hypocreales / classification
  • Hypocreales / genetics
  • Hypocreales / isolation & purification*
  • Lizards / microbiology
  • Lung / microbiology*
  • Metarhizium / genetics
  • Metarhizium / isolation & purification
  • Mycoses / microbiology
  • Phylogeny
  • Pneumonia / microbiology*
  • Reptiles / microbiology*
  • Zoonoses / microbiology
  • Zoonoses / transmission

Substances

  • DNA, Ribosomal
  • Fibrin