A RETROSPECTIVE STUDY OF HEPATIC HEMOSIDEROSIS AND IRON STORAGE DISEASE IN SEVERAL CAPTIVE AND FREE-RANGING AVIAN SPECIES.

Some wild species of mammals and birds are prone to excessive iron accumulation, especially when maintained in human care. Hemosiderosis is the process of intracellular accumulation of iron without evidence of toxicity, whereas hemochromatosis is characterized by severe iron accumulation with accompanying organ damage. Iron storage disease (ISD) occurs when organ damage is severe and causing clinical signs. This retrospective study investigated the occurrence of hemosiderosis and ISD across a variety of avian taxa, including captive and free-ranging birds. Archived paraffin-embedded hepatic samples from 103 birds from Belo Horizonte Zoo that died naturally in the period of 2008 to 2018 were re-evaluated with histologic and morphometric techniques, focusing on the identification and scoring of iron deposits in hepatocytes and the quantification of total affected hepatic area. The birds represented 13 orders, 22 families, and 52 genera, and 66 (64.0%) had some degree of iron accumulation in their liver. Importantly, no statistical difference was observed in the occurrence of iron accumulation between families, orders, or origin (free-ranging or captive). Direct and positive correlation was observed between the total area affected by the iron deposits and the histologic score. In this study, there were two cases with severe iron accumulation and clinical signs compatible with ISD: a barefaced curassow (Crax fasciolata) and a channel-billed toucan (Ramphastos vitellinus). This study indicates that iron accumulation may occur in a wide range of avian species, with frequencies and intensities that are similar between free-ranging birds and those in human care. It describes for the first time the occurrence of ISD in a Galliform species.

In vitro Infectivity of Strains Isolated From Dogs Naturally Infected With Leishmania infantum Present a Distinct Pathogenic Profile in Hamsters.

Visceral leishmaniasis (VL) is a severe disease caused by Leishmania infantum. Dogs are the parasite's main reservoir, favoring its transmission in the urban environment. The analysis of L. infantum from infected dogs contributes to the identification of more virulent parasites, thereby supporting basic and applied studies such as vaccinal and therapeutic strategies. We proposed the in vitro and in vivo characterization of L. infantum strains from naturally infected dogs from a VL endemic area based on an infectivity and pathogenicity analysis. DH82 canine macrophages were infected in vitro with different strains for infectivity analysis, showing distinct infectivity profiles. The strains that showed greater and lesser infectivity using in vitro analyses (616 and 614, respectively) were used to infect hamsters for pathogenicity analysis. The group infected with strain 616 showed 100% survival while the group infected with strain 614 showed 50% after seven months of follow up. Furthermore, the 614 strain induced more noticeable clinicopathological changes and biochemical abnormalities in liver function, along with high inflammation and parasite load in the liver and spleen. We confirmed high variability of infectivity and pathogenicity in L. infantum strains from infected dogs. The results support the belief that screening for L. infantum infectivity using in vitro experiments is inadequate when it comes to selecting the most pathogenic strain.

Evaluation of pathogenicity of Salmonella Gallinarum strains harbouring deletions in genes whose orthologues are conserved pseudogenes in S. Pullorum.

The diseases caused by Salmonella Gallinarum and S. Pullorum in chickens known as fowl typhoid and pullorum disease, respectively, pose a great threat to the poultry industry mainly in developing countries, since they have already been controlled in the developed ones. These bacteria are very similar at the genomic level but develop distinct host-pathogen relationships with chickens. Therefore, a deep understanding of the molecular mechanisms whereby S. Gallinarum and S. Pullorum interact with the host could lead to the development of new approaches to control and, perhaps, eradicate both diseases from the chicken flocks worldwide. Based on our previous study, it was hypothesised that metabolism-related pseudogenes, fixed in S. Pullorum genomes, could play a role in the distinct host-pathogen interaction with susceptible chickens. To test this idea, three genes (idnT, idnO and ccmH) of S. Gallinarum str. 287/91, which are pseudogenes on the S. Pullorum chromosomes, were inactivated by mutations. These genetically engineered strains grew well on the solid media without any colony morphology difference. In addition, similar growth curves were obtained by cultivation in M9 minimal medium containing D-gluconate as the sole carbon source. Infection of chickens with idnTO mutants led to increased numbers of bacteria in the livers and spleens at 5 days post-infection, but with slightly decreased heterophil infiltration in the spleens when compared to the wild-type strain. On the other hand, no significant phenotypic change was caused by mutation to ccmH genes. Apart from the above-mentioned alterations, all S. Gallinarum strains provoked similar infections, since mortality, clinical signs, macroscopic alterations and immune response were similar to the infected chickens. Therefore, according to the model applied to this study, mutation to the idnTO and ccmH genes showed minor impact on the fowl typhoid pathogenesis and so they may be relics from the ancestor genome. Our data hints at a more complex mechanism driving the distinct host-pathogen interaction of S. Gallinarum/Pullorum with chickens than differential inactivation of a few genes.

Visceral leishmaniasis in an infant gorilla (Gorilla gorilla gorilla): Clinical signs, diagnosis, and successful treatment with single-dose liposomal amphotericin B.

A 2-year-old captive gorilla (Gorilla gorilla gorilla) was diagnosed with visceral leishmaniasis in Brazil, and treated with a single dose of liposomal amphotericin B, which resulted in clinical cure. This is the first report of visceral leishmaniasis in gorillas, and the first reported liposomal amphotericin B treatment in great apes.

Tissue distribution and cell tropism of Brucella canis in naturally infected canine foetuses and neonates.

Brucella canis infection is an underdiagnosed zoonotic disease. Knowledge about perinatal brucellosis in dogs is extremely limited, although foetuses and neonates are under risk of infection due to vertical transmission. In this study, immunohistochemistry was used to determine tissue distribution and cell tropism of B. canis in canine foetuses and neonates. Diagnosis of B. canis in tissues of naturally infected pups was based on PCR and sequencing of amplicons, bacterial isolation, and immunohistochemistry, whose specificity was confirmed by laser capture microdissection. PCR positivity among 200 puppies was 21%, and nine isolates of B. canis were obtained. Tissues from 13 PCR-positive puppies (4 stillborn and 9 neonates) presented widespread immunolabeling. Stomach, intestines, kidney, nervous system, and umbilicus were positive in all animals tested. Other frequently infected organs included the liver (92%), lungs (85%), lymph nodes (69%), and spleen (62%). Immunolabeled coccobacilli occurred mostly in macrophages, but they were also observed in erythrocytes, epithelial cells of gastrointestinal mucosa, renal tubules, epidermis, adipocytes, choroid plexus, ependyma, neuroblasts, blood vessels endothelium, muscle cells, and in the intestinal lumen. These results largely expand our knowledge about perinatal brucellosis in the dog, clearly demonstrating a pantropic distribution of B. canis in naturally infected foetuses and neonates.

Hepatocellular carcinoma in two captive golden-headed lion tamarins (Leontopithecus chrysomelas).

Two cases of hepatocellular carcinoma (HCC) in 2 female captive golden-headed lion tamarins (Leontopithecus chrysomelas) are described. HCC was diagnosed in both, with pulmonary metastasis in one of them. Neoplastic cells were positive for hepatocyte-specific antigen (HSA) by immunohistochemistry, confirming the diagnosis.

ULCERATIVE AND NECROTIZING GASTRITIS IN A CAPTIVE SLOTH (BRADYPUS VARIEGATUS, XENARTHRA, BRADYPODIDAE) DUE TO SEVERE PARASITISM WITH PARALEIURIS LOCCHII (NEMATODA, SPIROCERCIDAE).

This is the first reported case of lethal gastric parasitism by the nematode Paraleiuris locchii in a captive sloth ( Bradypus variegatus ). There were more than 600 parasites in the stomach of the sloth, associated with extensive areas of ulceration and necrosis. The animal developed emaciation, dehydration, and anemia that progressed to death.