Metabolic disruptions in Biomphalaria glabrata induced by Heterorhabditis bacteriophora HP88: implications for entomopathogenic nematodes in biological control.

Research on the use of entomopathogenic nematodes (EPNs) as a potential tool for the biological control of invertebrates has been growing in recent years, including studies involving snails with One Health importance. In this study, the effect of exposure time (24 or 48 hours) of Heterorhabditis bacteriophora HP88 on the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as the concentration of total proteins, uric acid, and urea in the hemolymph of Biomphalaria glabrata, were investigated. The concentrations of these metabolic markers were measured weekly until the end of the third week after exposure. Along with a significant reduction in total protein levels, a significant increase (p<0.01) in uric acid and urea contents in the hemolymph of B. glabrata exposed to H. bacteriophora was observed. The accumulation of urea in these mollusks could lead to deleterious effects due to its high toxicity, inducing significant cell damage. Variations in transaminase activities were also observed, with snails exposed to EPNs showing significantly higher values (p<0.01) than individuals in the control group, both for ALT and AST. These results indicate that experimental exposure to infective juveniles of H. bacteriophora causes significant alterations in the metabolic pattern of B. glabrata, compromising the maintenance of its homeostasis. Finally, exposure for 48 hours caused more damage to the planorbid in question compared to snails exposed for 24 hours, suggesting that the exposure time may influence the intensity of the host's response.

Fasciolosis in ruminants in Brazil.

This review aims to promote discussion about the situation of fasciolosis in ruminants in Brazil. The disease is still found more frequently in the South and Southeast regions, but reports outside these areas show the spread of the disease, including human cases. Many studies have been published on the diagnosis and control of fasciolosis, but development of field diagnosis methods and drugs that control all stages of the parasite is still a challenge. Studies should be carried out of new distribution areas and alternatives for control in Brazil, which depends on understanding the complex interactions between of the environment, ecosystems and hosts of this trematode.

Esta revisão tem como objetivo levantar uma discussão sobre a situação da fasciolose em ruminantes no Brasil. A enfermidade ainda se encontra mais frequentemente nas regiões Sul e Sudeste do país, entretanto relatos fora dessas regiões evidenciam a expansão da enfermidade, inclusive casos em humanos. Muitos estudos têm sido publicados sobre o diagnóstico e controle da fasciolose, entretanto, o diagnóstico a campo e fármacos que combatam todas as fases evolutivas do parasito ainda são desafios. Novos estudos devem ser realizados sobre novas áreas de distribuição e alternativas de controle em condições brasileiras, o que depende da compreensão das complexas interações entre meio ambiente, ecossistemas e hospedeiros desse trematódeo.

Influence of exposure Heterorhabditis bacteriophora HP88, (Rhabditida: Heterorhabditidae) on biological and physiological parameters of Pseudosuccinea columella (Basommatophora: Lymnaeidae).

Many studies about fasciolosis control have been carried out, whether acting on the adult parasite or in Pseudosuccinea columella, compromising the development of the larval stages. The present study aimed to evaluate, under laboratory conditions, the susceptibility of P. columella to Heterorhabditis bacteriophora HP88, during for 24 and 48 hours of exposure. The snails were evaluated for 21 days for accumulated mortality; number of eggs laid; hatchability rate; biochemical changes; and histopathological analysis. We found that exposure induced a reduction in glucose and glycogen levels, characterizing a negative energy balance, due to the depletion of energy reserves as a result of the direct competition established by the nematode/endosymbiont bacteria complex in such substrates. A mortality rate of 48.25% and 65.52% was observed in the group exposed for 24 h and 48 h, respectively, along with significant impairment of reproductive biology in both exposed groups in relation to the respective controls. The results presented here show that P. columella is susceptible to the nematode H. bacteriophora, with the potential to be used as an alternative bioagent in the control of this mollusk, especially in areas considered endemic for fascioliasis, in line with the position expressed by the World Health Organization Health.

Eurytrematosis in cattle in southern Espírito Santo State, Brazil - case report.

This work reports an outbreak of eurytrematosis in cattle in the municipality of Ibitirama, southern Espírito Santo State, Brazil. Six cattle were necropsied from August to December 2019, with finding of Eurytrema coelomaticum in the pancreas. A survey of epidemiological data was carried out on the farms along with coproparasitological examination of cattle from the same herd. Parasites were found in all necropsied animals, with different degrees of parasitism, ranging from mild to massive infection (6 - 2000 specimens). Macroscopic analyses of the pancreas revealed changes in 83.33% (5/6) of the cases, and by microscopy, pancreatic fibrosis ranging from Grade I to Grade III was observed. Inspection of the grazing areas confirmed the presence of two intermediate hosts, a terrestrial snail of the Bradybaena genus, with larval forms of the trematode in histological findings, and a grasshopper of the Conocephalus genus. Although none of the cattle showed clinical signs in the coproparasitological examination, 73.80% (31/42) tested positive for E. coelomaticum eggs. This is the first record of an outbreak of eurytrematosis in cattle in Espírito Santo State, indicating the importance of carrying out diagnosis based on epidemiology and necroscopic and parasitological examinations in animals in the region so that appropriate control measures can be adopted.

Este trabalho objetivou relatar um caso de euritrematose em bovinos no município de Ibitirama, Sul do Estado do Espírito Santo, Brasil. Foram necropsiados seis bovinos de agosto a dezembro de 2019, que apresentaram Eurytrema coelomaticum no pâncreas. Foi realizado levantamento de dados epidemiológicos nas propriedades e exames coproparasitológico em bovinos do mesmo plantel. Em todos os animais necropsiados foram encontrados parasitos, com diferentes graus de parasitismo, variando de infeção branda a maciça (6 - 2000 exemplares). Análises macroscópicas dos pâncreas revelaram alterações em 83,33% (5/6) dos casos e, na microscopia, observou-se fibrose pancreática variando de Grau I a Grau III. A inspeção das áreas de pastejo constatou a presença dos dois hospedeiros intermediários, moluscos terrestres do gênero Bradybaena com formas larvares do trematoda em achados histológicos e gafanhotos do gênero Conocephalus. Nenhum dos bovinos apresentou sinais clínicos, no entanto, no exame coproparasitológico, 73,80% (31/42) testaram positivo para ovos de E. coelomaticum. Este é o primeiro registro de surto de euritrematose em bovinos no estado do Espírito Santo, mostrando a importância da realização do diagnostico a partir da epidemiologia e de exames necroscópicos e parasitológicos em animais da região para que sejam adotadas medidas adequadas de controle.