Invasive Colonic Entamoebiasis in Wild Cane Toads, Australia

We detected a disease syndrome in free-ranging Australian cane toads involving atypical behavior and emaciation that is associated with a previously undescribed Entamoeba sp. that infiltrates the colonic lining, causing it to slough. The organism may become seasonally pathogenic when toads are under hydric and nutritional stress

The Change of a Medically Important Genus: Worldwide Occurrence of Genetically Diverse Novel <i>Brucella</i> Species in Exotic Frogs

<div><p>The genus <i>Brucella</i> comprises various species of both veterinary and human medical importance. All species are genetically highly related to each other, sharing intra-species average nucleotide identities (ANI) of > 99%. Infections occur among various warm-blooded animal species, marine mammals, and humans. Until recently, amphibians had not been recognized as a host for <i>Brucella</i>. In this study, however, we show that novel <i>Brucella</i> species are distributed among exotic frogs worldwide. Comparative <i>recA</i> gene analysis of 36 frog isolates from various continents and different frog species revealed an unexpected high genetic diversity, not observed among classical <i>Brucella</i> species. In phylogenetic reconstructions the isolates consequently formed various clusters and grouped together with atypical more distantly related brucellae, like <i>B</i>. <i>inopinata</i>, strain BO2, and Australian isolates from rodents, some of which were isolated as human pathogens. Of one frog isolate (10RB9215) the genome sequence was determined. Comparative genome analysis of this isolate and the classical <i>Brucella</i> species revealed additional genetic material, absent from classical <i>Brucella</i> species but present in <i>Ochrobactrum</i>, the closest genetic neighbor of <i>Brucella</i>, and in other soil associated genera of the <i>Alphaproteobacteria</i>. The presence of gene clusters encoding for additional metabolic functions, flanked by tRNAs and mobile genetic elements, as well as by bacteriophages is suggestive for a different ecology compared to classical <i>Brucella</i> species. Furthermore it suggests that amphibian isolates may represent a link between free living soil saprophytes and the pathogenic <i>Brucella</i> with a preferred intracellular habitat. We therefore assume that brucellae from frogs have a reservoir in soil and, in contrast to classical brucellae, undergo extensive horizontal gene transfer.</p></div

Core-genome-based phylogenetic neighbor-joining tree with 200 repetitions.

<p>Bar: 0.002 substitutions per site. Isolate 10RB9215 is indicated in bold letters. Accession numbers are given in brackets.</p

History and origin of ‘atypical’ <i>Brucella</i> strains isolated from amphibian host species.

<p>(wc): wild caught, (cb): captive bred.</p

<i>Phylogenetic tree</i> from maximum likelihood analysis of the <i>recA</i> gene alignment of <i>Brucella</i> isolates from exotic frogs including classical and ‘atypical’ <i>Brucella</i> species.

<p>The tree was calculated with 100 bootstrap repetitions. <i>Ochrobactrum</i> served as outgroup. Bar: 0.08 substitutions per site. Accession numbers are given in brackets.</p

Sunshine virus in Australian pythons

Sunshine virus is a recently discovered novel paramyxovirus that is associated with illness in snakes. It does not phylogenetically cluster within either of the two currently accepted paramyxoviral subfamilies. It is therefore only distantly related to the only other known genus of reptilian paramyxoviruses, Ferlavirus, which clusters within the Paramyxovirinae subfamily. Clinical and diagnostic aspects associated with Sunshine virus are as yet undescribed. The objective of this paper was to report the clinical presentation, virus isolation, PCR testing and pathology associated with Sunshine virus infection. Clinical records and samples from naturally occurring cases were obtained from two captive snake collections and the archives of a veterinary diagnostic laboratory. The clinical signs that are associated with Sunshine virus infection are localised to the neurorespiratory systems or are non-specific (e.g. lethargy, inappetence). Out of 15 snakes that were infected with Sunshine virus (detected in any organ by either virus isolation or PCR), the virus was isolated from four out of ten (4/10) sampled brains, 3/10 sampled lungs and 2/7 pooled samples of kidney and liver. In these same 15 snakes, PCR was able to successfully detect Sunshine virus in fresh-frozen brain (11/11), kidney (7/8), lung (8/11) and liver (5/8); and various formalin-fixed paraffin-embedded tissues (7/8). During a natural outbreak of Sunshine virus in a collection of 32 snakes, the virus could be detected in five out of 39 combined oral-cloacal swabs that were collected from 23 of these snakes over a 105 day period. All snakes that were infected with Sunshine virus were negative for reovirus and ferlavirus by PCR. Snakes infected with Sunshine virus reliably exhibited hindbrain white matter spongiosis and gliosis with extension to the surrounding grey matter and neuronal necrosis evident in severe cases. Five out of eight infected snakes also exhibited mild bronchointerstitial pneumonia. Infection with Sunshine virus should be considered by veterinarians investigating disease outbreaks in snakes, particularly those that are associated with neurorespiratory disease