Metastatic Sertoli cell tumour in a captive giant anteater (Myrmecophaga tridactyla).

There are a few studies on diseases of anteaters, but reports on reproductive lesions and neoplasms of these animals are scarce. This is the first report of a case of metastatic Sertoli cell tumour in a giant anteater (Myrmecophaga tridactyla). The animal had renal lesions associated with impaired renal function as indicated by serum biochemistry. Histopathological and immunohistochemical examinations provided a conclusive diagnosis of Sertoli cell tumour with metastasis to the liver, kidneys and lymph nodes.

Hemoplasma infection in wild captive carnivores / Infecção por hemoplasmas em carnívoros selvagens cativos

Hemoplasmas are bacteria able to adhere themselves loosely to the plasma membrane of erythrocytes and may parasitize several species of mammals. There are three known species of hemoplasmas that parasitize domestic and wild cats: Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' and 'Candidatus Mycoplasma turicensis'. Dogs are infected by at least two species of hemoplasmas: 'Candidatus Mycoplasma haematoparvum' and Mycoplasma haemocanis. The hemoplasmoses are very important in veterinary clinics, either because of its worldwide distribution and severity of clinical signs, depending on parasite species and host immune competence, or due to its zoonotic potential and capability of infecting endangered species. This study set out to investigate which hemoplasmas species parasitize different captive wild carnivores in order to clarify the epidemiology of hemoplasmoses in wild animals. Furthermore, the research intended to characterize the hematological changes caused by different species of hemotropic mycoplasmas infection in order to establish their clinical importance to wild species and the capacity of these species to become a reservoir of studied agents. Samples of 33 wild felids and 18 wild canids were investigated using polymerase chain reaction (PCR) to detect hemoplasmas DNA and it was observed that the occurrence of infection in these species is 45.5% and 83.3%, respectively. Factors such as age, gender or anaemia are not more frequent in animals positive for the infection. Therefore, it is concluded that infection caused by hemoplasmas in wild carnivores has high prevalence, and either agent pathogenicity is low, or chronic stage is more frequent, resulting in a low rate of diagnosis.(AU)

Hemoplasmas são bactérias capazes de aderir frouxamente à membrana plasmática de eritrócitos e que podem parasitar diversas espécies de mamíferos. São conhecidas três espécies de hemoplasmas que parasitam felídeos domésticos e selvagens: Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' and 'Candidatus Mycoplasma turicensis'. Cães são infectados por ao menos duas espécies de hemoplasmas: Candidatus Mycoplasma haematoparvum' and Mycoplasma haemocanis. As hemoplasmoses são de grande importância na clínica veterinária, tanto pela sua distribuição ubíqua e severidade dos sinais clínicos, a depender da espécie do parasita e imunocompetência do hospedeiro, quanto pelo seu potencial zoonótico e capacidade de infectar espécies ameaçadas. Este estudo visa investigar quais espécies de hemoplasmas parasitam diferentes carnívoros selvagens de cativeiro, a fim de esclarecer a epidemiologia das hemoplasmoses em animais selvagens. Além disso, o trabalho objetivou caracterizar as alterações hematológicas causadas pela infecção por diferentes espécies de micoplasmas hemotrópicos visando estabelecer sua importância clínica para espécies selvagens e a capacidade destas espécies de se tornar reservatórios dos agentes estudados. Amostras de 33 felídeos selvagens e de 18 canídeos selvagens foram investigadas por meio da reação em cadeia da polimerase (RCP) para detectar o DNA dos agentes e foi observado que a ocorrência da infecção por hemoplasmas nestas espécies é de 45,5% e 83,3%, respectivamente. Fatores como idade, sexo ou anemia não são mais frequentes em animais positivos para a infecção. Dessa forma, conclui-se que a infecção causada por hemoplasmas em carnívoros selvagens possui alta prevalência, no entanto ou a patogenicidade dos agentes é baixa ou o estágio crônico da infecção é mais frequente, resultando em uma baixa frequência diagnóstica.(AU)

Sialoglycoconjugates in Herpetomonas megaseliae: role in the adhesion to insect host epithelial cells.

Herpetomonas megaseliae is a monoxenic trypanosomatid isolated from the phorid fly Megaselia scalaris. In the present report, the expression of cell surface sialoglycoconjugates in this parasite was analyzed by Western blotting, flow cytometry and fluorescence microscopy analyses using lectins that specifically recognize sialic acid residues. A strong reaction was detected when parasites were treated with Limax flavus, Maackia amurensis and Sambucus nigra lectins. Analysis of crude protein extracts by Western blotting revealed that bands with molecular masses ranging from 19 to 80 kDa were reactive to these lectins, which showed a sugar-inhibited recognition with the parasite extract. These results indicated that molecules containing alpha2,3- and alpha2,6-sialylgalactosyl sequences are present in this protozoan. The role of the surface sialomolecules in the interaction with explanted guts from Aedes aegypti was assessed. The interaction of H. megaseliae with the insect gut was strongly inhibited in the presence of mucin (71%), fetuin (68%) and sialyllactose (68%). Collectively, our results suggest a possible involvement of sialomolecules in the interaction between this insect trypanosomatid and the invertebrate host.

Cysteine peptidases in the tomato trypanosomatid Phytomonas serpens: influence of growth conditions, similarities with cruzipain and secretion to the extracellular environment.

We have characterized the cysteine peptidase production by Phytomonas serpens, a tomato trypanosomatid. The parasites were cultivated in four distinct media, since growth conditions could modulate the synthesis of bioactive molecules. The proteolytic profile has not changed qualitatively regardless the media, showing two peptidases of 38 and 40kDa; however, few quantitative changes were observed including a drastic reduction (around 70%) on the 40 and 38kDa peptidase activities when parasites were grown in yeast extract and liver infusion trypticase medium, respectively, in comparison with parasites cultured in Warren medium. The time-span of growth did not significantly alter the protein and peptidase expression. The proteolytic activities were blocked by classical cysteine peptidase inhibitors (E-64, leupeptin, and cystatin), being more active at pH 5.0 and showing complete dependence to reducing agents (dithiothreitol and l-cysteine) for full activity. The cysteine peptidases were able to hydrolyze several proteinaceous substrates, including salivary gland proteins from Oncopeltus fasciatus, suggesting broad substrate utilization. By means of agglutination, fluorescence microscopy, flow cytometry and Western blotting analyses we showed that both cysteine peptidases produced by P. serpens share common epitopes with cruzipain, the major cysteine peptidase of Trypanosoma cruzi. Moreover, our data suggest that the 40kDa cysteine peptidase was located at the P. serpens cell surface, attached to membrane domains via a glycosylphosphatidylinositol anchor. The 40kDa peptidase was also detected in the cell-free culture supernatant, in an active form, which suggests secretion of this peptidase to the extracellular environment.

Phytomonas serpens: cysteine peptidase inhibitors interfere with growth, ultrastructure and host adhesion.

In this study, we report the ultrastructural and growth alterations caused by cysteine peptidase inhibitors on the plant trypanosomatid Phytomonas serpens. We showed that the cysteine peptidase inhibitors at 10 microM were able to arrest cellular growth as well as promote alterations in the cell morphology, including the parasites becoming short and round. Additionally, iodoacetamide induced ultrastructural alterations, such as disintegration of cytoplasmic organelles, swelling of the nucleus and kinetoplast-mitochondrion complex, which culminated in parasite death. Leupeptin and antipain induced the appearance of microvillar extensions and blebs on the cytoplasmic membrane, resembling a shedding process. A 40 kDa cysteine peptidase was detected in hydrophobic and hydrophilic phases of P. serpens cells after Triton X-114 extraction. Additionally, we have shown through immunoblotting that anti-cruzipain polyclonal antibodies recognised two major polypeptides in P. serpens, including a 40 kDa component. Flow cytometry analysis confirmed that this cruzipain-like protein has a location on the cell surface. Ultrastructural immunocytochemical analysis demonstrated the presence of the cruzipain-like protein on the surface and in small membrane fragments released from leupeptin-treated parasites. Furthermore, the involvement of cysteine peptidases of P. serpens in the interaction with explanted salivary glands of the phytophagous insect Oncopeltus fasciatus was also investigated. When P. serpens cells were pre-treated with either cysteine peptidase inhibitors or anti-cruzipain antibody, a significant reduction of the interaction process was observed. Collectively, these results suggest that cysteine peptidases participate in several biological processes in P. serpens including cell growth and interaction with the invertebrate vector.