ABSTRACT Hepatic injuries in COVID-19 are not yet fully understood and indirect pathways (without viral replication in the liver) have been associated with the activation of vascular mechanisms of liver injury in humans infected with SARS-CoV-2. Golden Syrian hamsters are an effective model for experimental reproduction of moderate and self-limiting lung disease during SARS-CoV-2 infection. As observed in humans, this experimental model reproduces lesions of bronchointerstitial pneumonia and pulmonary vascular lesions, including endotheliitis (attachment of lymphoid cells to the luminal surface of endothelium). Extrapulmonary vascular lesions are well documented in COVID-19, but such extrapulmonary vascular lesions have not yet been described in the Golden Syrian hamster model of SARS-CoV-2 infection. The study aimed to evaluate microscopic liver lesions in Golden Syrian hamsters experimentally infected with SARS-CoV-2. In total, 38 conventional Golden Syrian hamsters, divided into infected group (n=24) and mock-infected group (n=14), were euthanized at 2-, 3-, 4-, 5-, 7-, 14-, and 15-days post infection with SARS-CoV-2. Liver fragments were evaluated by histopathology and immunohistochemical detection of SARS-CoV-2 Spike S2 antigens. The frequencies of portal vein endotheliitis, lobular activity, hepatocellular degeneration, and lobular vascular changes were higher among SARS-CoV-2-infected animals. Spike S2 antigen was not detected in liver. The main results indicate that SARS-CoV-2 infection exacerbated vascular and inflammatory lesions in the liver of hamsters with pre-existing hepatitis of unknown origin. A potential application of this animal model in studies of the pathogenesis and evolution of liver lesions associated with SARS-CoV-2 infection still needs further evaluation. COVID19 COVID 19 COVID-1 without SARSCoV2. SARSCoV2 SARSCoV SARS CoV 2. 2 selflimiting self limiting SARS-CoV- attachment endothelium. endothelium . endothelium) COVID19, 19, total 3 n=24 n24 n 24 (n=24 mockinfected mock n=14, n14 n=14 , 14 (n=14) 2, 2- 3, 3- 4, 4 4- 5, 5 5- 7, 7 7- 14, 14- 15days days 15 S antigens activity degeneration SARSCoV2infected SARSCoVinfected animals preexisting pre existing origin evaluation COVID1 1 COVID- SARS-CoV n=2 n2 (n=2 n1 n=1 (n=14 n= (n= (n=1 (n

Resumo O objetivo deste estudo foi registrar a primeira ocorrência de Synhimantus (Dispharynx) nasuta (Nematoda: Acuariidae) em algumas espécies de aves silvestres do Brasil. Além disso, pretendeu-se aprofundar o conhecimento sobre a morfologia desta espécie por meio de análises por microscopia eletrônica de varredura. Os nematoides foram coletados em aves silvestres das espécies Turdus leucomelas, T. rufiventris, Mimus saturninus, Pitangus sulphuratus, Megascops choliba, Tyto furcata e Falco sparverius. Os dados morfológicos e morfométricos observados nos nematoides comprovaram que esses parasitos são S. (D.) nasuta. Este estudo também fornece dados morfológicos de microscopia de luz e microscopia eletrônica de varredura (MEV), assim como a morfometria deste nematoide em cada espécie de hospedeiro. Portanto, o presente estudo confirma o primeiro registro desse nematoide em F. sparverius e T. furcata na América do Sul e, ao mesmo tempo, esses achados ampliam a gama de hospedeiros dessa espécie de parasito em todo o mundo, por meio dos primeiros registros em M. choliba, M. saturninus, T. leucomelas e T. rufiventris. Dispharynx (Dispharynx Nematoda (Nematoda Acuariidae Brasil disso pretendeuse pretendeu se T rufiventris saturninus sulphuratus choliba S D. D (D. MEV, MEV , (MEV) hospedeiro Portanto F tempo mundo M (D (MEV

Abstract The aim of this study was to register the first occurrence of Synhimantus (Dispharynx) nasuta (Nematoda: Acuariidae) in some species of wild birds in Brazil. In addition, the aim was to deepen the knowledge about the morphology of this species through analysis using scanning electron microscopy. Nematodes were collected in wild birds of the species Turdus leucomelas, T. rufiventris, Mimus saturninus, Pitangus sulphuratus, Megascops choliba, Tyto furcata, and Falco sparverius. The morphological and morphometric data observed in the nematodes prove that these parasites are S. (D.) nasuta. This study also provides morphological data from light microscopy and scanning electron microscopy (SEM), as well as the morphometry of this nematode in each host species. Therefore, the current study confirms the first record of this nematode in F. sparverius and T. furcata in South America and, at the same time, these findings expand the host range of this parasite species worldwide, through the first records in M. choliba, M. saturninus, T. leucomelas and T. rufiventris. Dispharynx (Dispharynx Nematoda (Nematoda Acuariidae Brazil addition T rufiventris saturninus sulphuratus choliba S D. D (D. SEM, SEM , (SEM) Therefore F time worldwide M (D (SEM

O presente estudo objetivou descrever as lesões pulmonares macro e microscópicas associadas ao parasitismo por Sebekia oxycephala em 100 espécimes de jacarés-açu (Melanosuchusniger), abatidos na Reserva de Desenvolvimento Sustentável Mamirauá, situada no Estado do Amazonas, Brasil. Durante a avaliação macroscópica, exemplares dos parasitos encontrados no tecido pulmonar foram coletados individualmente em AFA (Álcool etílico - Formalina - Ácido acético glacial) e formol a 5% para avaliação parasitológica e classificação taxonômica. Amostras de tecido pulmonar de todos os animais, independentemente da ocorrência de lesões macroscópicas, foram fixadas em formol 10% e incluídas em parafina. Secções histológicas coradas por Hematoxilina-Eosina destas amostras foram avaliadas por meio de microscopia óptica. Macroscopicamente, 4 dos 100 animais (4%) apresentaram espécimes de pentastomídeos no parênquima pulmonar. Os parasitos foram classificados taxonomicamente como pertencentes à espécie Sebekia oxycephala. Nenhuma alteração macroscópicas foi observada, porém, microscopicamente, lesões pulmonares foram encontradas em 37% dos casos, sendo que, lesões inflamatórias associadas ao parasitismo corresponderam a 75,6% dos mesmos (28/37). Nestes, segmentos degenerados e ovos de S. oxycephala encontravam-se envolvidos por cápsula de tecido conjuntivo fibroso e infiltrado inflamatório predominantemente composto por células gigantes do tipo corpo estranho. Três espécimes apresentaram espessamento de septos alveolares e sete exemplares continham infiltrado inflamatório granulocítico multifocal no parênquima pulmonar. As lesões associadas ao parasitismo, de modo geral, apresentaram intensidade discreta e parecem não representar uma causa importante de doença pulmonar entre a população estudada. Esta é a primeira descrição de lesões pulmonares em M. niger associadas ao parasitismo por S. oxycephala na Amazônia brasileira.

The goal of this study was to describe gross and microscopic lung lesions associated with the parasitism by Sebekia oxycephala between 100 specimens of black caiman (Melanosuchus niger) slaughtered in the Mamirauá Sustainable Development Reserve, situated in the Amazonas State, Brazil. During the macroscopic evaluation, specimens of parasites found in the lung tissue were collected individually in AFA (ethyl alcohol - formalin - glacial acetic acid) and 5% formalin for parasitological evaluation and taxonomic classification. Lung tissue samples of all the animals, regardless of the occurrence of gross lesions, were fixed in 10% formalin and embedded in paraffin. Histological sections obtained from the samples stained by Hematoxylin-Eosin were evaluated by light microscopy. Grossly, 4 of the 100 animals (4%) presented pentastomid specimens in the lung parenchyma. These parasites were taxonomically classified as Sebekia oxycephala. No macroscopic alterations were observed, however microscopically pulmonary lesions were found in 37% of the cases, and inflammatory lesions associated with the parasitism corresponded to 75.6% of them (28/37). In these cases, degenerate segments and eggs of S. oxycephala were surrounded by a fibrous capsule and inflammatory infiltrate composed predominantly by foreign body giant cells. Three specimens exhibited thickening of the alveolar septa and seven specimens presented multifocal inflammatory granulocytic infiltration in the lung parenchyma. Generally, the associated parasitic lesions had mild intensity and did not appear to represent an important cause of lung disease in the studied population. This is the first description of lung lesions in M. niger associated with parasitism by S. oxycephala in the Brazilian Amazon.