Moderate pathogenic effect of Ligophorus uruguayense (Monogenoidea, Ancyrocephalidae) in juvenile mullet Mugil liza (Actinopterygii, Mugilidae) from Brazil

ABSTRACT Monogenoidea pathogenic activity can elicit various histological responses in fish. Species of Ligophorus are specific parasites of mullets, and its relationship with host fish may result in a moderate pathogenic action. In order to ascertain this relationship, estuarine mullets (Mugil liza) were collected in an estuary, reared in laboratory, for three weeks, and forwarded for histological and parasitological analyses. Ligophorus uruguayense (Monogenoidea) infestation in the gills of the mullets was identified. The severe infestation by only one species of Monogenoidea may result from the specificity of these parasites to mullets. Mullets submitted to histological analysis exhibited respiratory epithelium detachment; mild, moderate and severe hyperplasia of the respiratory epithelium; atrophy; and telangiectasia of the gills. This is the first study reporting that mullets highly infested by Monogenoidea can show mild (100%) to severe (20%) gill changes with a distinct frequency of occurrence. Because of the high prevalence of mild alterations observed, it is possible to accept that L. uruguayense is moderately pathogenic to M. liza, even during high prevalence and intensity of infestation, as a result of its specificity.

Feline platynosomiasis: analysis of the association of infection levels with pathological and biochemical findings / Platinossomiase felina: análise da associação dos níveis de infecção com achados patológicos e bioquímicos

Abstract Platynosomiasis is a common feline hepatic disease caused by Platynosomum fastosum (Trematoda - Dicrocoelidae), which is also known as ‘lizard poisoning’. Most reports of feline platynosomiasis show that this disease is sporadic and manifests with uncommon lesions; its pathogenicity is still not well understood. This study aimed to describe liver injuries and enzymatic changes associated with natural P. fastosum infection in 47 stray cats in an endemic area. Overall, 38.3% (18/47) of cats were parasitized, and 2,358 flukes (P. fastosum) were collected (131 – mean intensity of parasitism; 50.2 – mean abundance). The alanine transaminase (ALT) measure was significantly higher in parasitized animals, while alkaline phosphatase (ALP) showed no statistical difference between parasitized and non-parasitized animals. In infected animals, gross pathological lesions and microscopic liver injuries ranged from mild to severe, and were similar to those in previous descriptions of feline platynosomiasis. Nonetheless, the intensity of parasitism was not related to the severity of macroscopic or microscopic hepatic injuries. However, feline platynosomiasis should be considered in the differential diagnosis of feline liver disorders, as well as, in any program of helminth control, even if no clinical abnormalities are present.

Resumo Platinossomiase é uma doença hepática felina comum causada por Platynosomum fastosum (Trematoda - Dicrocoelidae), também é conhecida como “envenenamento por lagartixa”. A maioria dos relatos de platinossomiase felina mostra que esta doença é esporádica e se manifesta com lesões incomuns; sua patogenicidade ainda não é bem compreendida. Este estudo objetivou descrever as lesões no fígado e alterações enzimáticas associadas à infecção natural por P. fastosum em 47 gatos errantes em uma área endêmica. No total, 38,3% (18/47) dos gatos estavam parasitados, e 2.358 trematódeos (P. fastosum) foram coletados (131 – intensidade média de parasitismo; 50,2 – abundância média). A quantidade de alanina transaminase (ALT) foi significativamente maior nos animais parasitados, enquanto a fosfatase alcalina (ALP) não apresentou diferença estatística entre os animais parasitados e não parasitados. Nos animais infectados, lesões patológicas macroscópicas e microscópicas hepáticas variaram de leve a grave, e foram semelhantes a descrições anteriores de platinossomiase felina. No entanto, a intensidade do parasitismo não foi relacionada à gravidade das lesões hepáticas macroscópicas ou microscópicas. Contudo, a platinossomiase felina deve ser considerada no diagnóstico diferencial de distúrbios hepáticos em felinos, assim como, em qualquer programa de controle de helmintos, mesmo que nenhuma anormalidade clínica esteja presente.

First record of Paratanaisia bragai (Digenea: Eucotylidae) in blue and gold macaw (Ara ararauna) / Primeiro registro de Paratanaisia bragai (Digenea: Eucotylidae) em arara Canindé (Ara ararauna)

Abstract The aim of this study was to provide the first report on a new host for the digenean Paratanaisia bragai in the caninde macaw Ara ararauna along with the pathological aspects of the infection in the new host. The microscopic findings revealed the presence of granulomatous interstitial nephritis. This study contributes towards knowledge of parasitism by P. bragai in A. ararauna, and emphasizes the need to use best practices in wildlife conservation parks.

Resumo O objetivo deste estudo foi relatar, pela primeira vez, a arara canindéAra ararauna como um novo hospedeiro para o digenéticoParatanaisia bragai, bem como relatar aspectos patológicos relacionados à infecção no novo hospedeiro. Os achados microscópicos revelaram nefrite intersticial granulomatosa. Este estudo contribui para o conhecimento do parasitismo por P. bragai em A. ararauna e ainda faz um alerta para a adoção de boas práticas de criação em criatórios conservacionistas da fauna silvestre.

Pathological and parasitological characterization of infection by trematodes (Paramphistomatidae) in the large intestine of capybaras / Caracterização patológica e parasitológica da infecção por trematódeos (Paramphistomatidae) no intestino grosso de capivaras

Gross and histological lesions caused by an intestinal parasite were described in three capybaras. The parasites presented a mean length of 14 mm and width of 7 mm, were round to oval or piriform, reddish and pedunculated, and adhered strongly to the mucosa of the large intestine. The intestinal mucosa at the parasite attachment site presented loss of surface epithelium and most glands, with replacement by fibrovascular proliferation that protruded from the mucosa and was involuted by the ventral sucker of the parasite. The lamina propria presented cellular debris, eosinophils, macrophages and plasma cells. The morphological characteristics, observed using serial histological sections, made it possible to classify the parasite as a trematode (Paramphistomatidae), compatible with Taxorchis schistocotyle. One capybara also harbored many ciliated protozoa in the large intestine (at the site of attachment of the parasite) and inside the caeca of the trematodes. In conclusion, this study described a multifocal necrotizing colitis associated with T. schistocotyle parasitism in capybaras.

Lesões macroscópicas e histológicas causadas por um parasita intestinal foram descritas em três capivaras. Os parasitas apresentaram média de 14 mm de comprimento e 7 mm de largura, eram de circulares a ovais ou piriformes, avermelhados, pedunculados e estavam fortemente aderidos à mucosa do intestino grosso. A mucosa intestinal, em que os parasitas estavam aderidos, apresentou perda do epitélio e da maioria das glândulas, sendo substituídos por proliferação fibrovascular que se projetava a partir da mucosa e era envolvida pela ventosa ventral do parasita. A lâmina própria apresentou restos celulares, eosinófilos, macrófagos e plasmócitos. As características morfológicas, utilizando cortes histológicos seriados, proporcionaram a classificação do parasita como um trematoda Paramphistomatidae, compatível com Taxorchis schistocotyle. Uma capivara continha também numerosos protozoários ciliados no intestino grosso (no local de fixação do parasita) e no lúmen do ceco desses parasitos. Em síntese, este estudo demonstrou a ocorrência de colite necrótica associada ao parasitismo por T. schistocotyle em capivaras.

Histopathological changes in the kidneys of vertebrate hosts infected naturally and experimentally withParatanaisia bragai (Trematoda, Digenea)

Paratanaisia bragai is a trematode parasite that reaches sexual maturity in the kidney collecting ducts of domesticated and wild fowl and whose intermediate hosts are the snails Subulina octona and Leptinaria unilamellata. There are some discrepancies in descriptions of the pathology of this parasite in bird kidneys. Therefore, the purpose of this study was to analyze the kidneys of rock pigeons (Columba livia) naturally infected and of chickens (Gallus gallus) experimentally infected with Paratanaisia bragai, by means of macroscopic observation and by light and scanning electron microscopy. Both bird species showed significantly dilated collecting ducts. In addition, lymphocyte infiltration was observed in the kidneys of C. livia and metaplasia in the epithelial lining of the kidney collecting ducts of G. gallus.

Paratanaisia bragai é um trematódeo que atinge sua maturidade sexual nos ductos coletores de rins de aves domésticas e silvestres, tendo os moluscos Subulina octona e Leptinaria unilamellata como hospedeiros intermediários. A patologia descrita no rim das aves apresenta uma série de divergências. Dessa forma, o presente estudo teve como objetivo analisar rins de Columba livia, naturalmente infectada, e de Gallus gallus infectados experimentalmente por Paratanaisia bragai. Através das análises, verificaram-se alterações macroscópicas, por microscopia de luz e eletrônica de varredura, sendo caracterizada significativa dilatação dos túbulos coletores. Essas alterações foram observadas nas aves infectadas naturalmente e experimentalmente. Por outro lado, foi observada infiltração linfocitária nos rins de C. livia, naturalmente infectada, e ocorrência de metaplasia no revestimento epitelial dos túbulos coletores dos rins de G. gallus, experimentalmente infectados.

Prevalence and pathology of the nematode Heterakis gallinarum, the trematode Paratanaisia bragai, and the protozoan Histomonas meleagridis in the turkey, Meleagris gallopavo

The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum appeared with a prevalence of 70 percent in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis. Histological findings in the ceca were represented by the presence of H. gallinarum worms, intense chronic diffuse inflammatory processes with mononuclear and polymorphonuclear (heterophils) leucocyte infiltrations. The prevalence of the protozoan H. meleagridis associated to H. gallinarum was of 2.5 percent and microscopic examination revealed a severe inflammatory process in the liver and cecum with the presence of small clear areas with round eosinophilic parasites. Gross lesions were absent in turkeys infected with the renal digenetic trematode Paratanaisia bragai; the parasite was prevalent in 20 percent of the cases and cross-sections of the kidneys showed a remarkable distension of the collecting ducts with several worms in the lumen. The walls of the ducts presented a discrete heterophilic infiltrate among mononuclear cells.

Pathology and first report of natural infections of the eye trematode Philophthalmus lachrymosus Braun, 1902 (Digenea, Philophthalmidae) in a non-human mammalian host

The avian eye trematode Philophthalmus lachrymosus Braun, 1902 is for the first time referred naturally occurring in a non-human mammalian host. Previously, natural infections with P. lachrymosus and other species of Philophthalmus have been occasionally reported from man, with few data on experimental infections of non-human mammals. Results presented here are related to the report of two cases of philophthalmosis due to natural infections of wild Brazilian capybaras, Hydrochaeris hydrochaeris L., 1766 with P. lachrymosus and associated pathology. Clinical signs, gross and microscopic lesions as well as new morphometric data on the parasite are presented.

Pathology and first occurrence of the kidney trematode Paratanaisia bragai (Santos, 1934) Freitas, 1959 (Digenea: Eucotylidae) in Phasianus colchicus L., 1758, from Brazil

The kidney trematode Paratanaisia bragai is reported for the first time parasitizing the ring-necked pheasant (Phasianus colchicus L., 1758) and the pathological alterations associated to the parasitism are referred on the basis of 50 specimens of this bird from backyard flocks in 11 counties of the state of Rio de Janeiro, Brazil after clinical examination, necropsies, and histopathological analysis. The counting of the kidney flukes was based on worms recovered from one of the kidneys, since the other was fixed in 10 percent formalin and then routinely processed for histopathological procedures. The prevalence of P. bragai was of 22 percent, with a mean intensity of 44.3, mean abundance of 9.7, and range of infection of 3-153. Parasitized birds did not present with clinical signs and kidney gross lesions. Microscopic lesions were mild and characterized by dilatation of the renal medullary collecting ducts, occasional flattening of the lining epithelium of the ducts and inflammatory reaction of variable intensity with granulocytes around the ureter branches and medullary collecting ducts. The severity and pattern of the microscopic lesions seem not to be associated to the size of the worm burden and could be related to the mechanic action of the parasites, without traumatism, in despite of the presence of the tegumentar spines in specimens of P. bragai.

Studies on heterophyid infections among some fishes in Egypt

A total number of 300 fishes [Oreochromis niloticus, Mugil cephalus and fingerling of Ctenopharyngodon idella "grass carp"] were collected from river Nile at Giza, Wadi Al-Rayan [Fayoum province] and Abbassa aquaculture [Sharkiya province] respectively. Encysted metacercariae of the heterophyid were collected from the muscles and gills of the examined fish, with prevalence 74.33%.Three groups each consisted of one pigeon [Columbia livia domestica] and one heron [Ardea ibis ibis], which were experimentally fed with heterophyid metacercariae collected from examined fishes. The fourth group [one pigeon and one heron] was kept as non-infected controls. Pygidiopsis genata, P. summa, Centrocestus armatus, Heterophyes equalis, H. dispar and H. heroni n.sp. were recovered from the intestinal mucosa, one week post infection. These parasites are of zoonotic importance. Histopathological effect of encysted metacercariae and obtained flukes was studied