The present study describes light microscopy, transmission electron microscopy, and molecular analyses of a myxosporid found parasitizing the gill region of the teleost fish Cichla temensis, collected from the Tocantins River, near Cametá, Pará State, Brazil. The prevalence of infection was 60 %. The spore-containing cysts that were located in the gill lamellae were oval and whitish. The spores had a mean length of 42.3 ± 0.65 μm; fusiform body, 12.8 ± 0.42-μm long and 8.6 ± 0.32-μm wide; each of the two valves exhibited a tapering tail of 29.5 ± 0.73 μm length. The spores had two polar capsules, 7.4 ± 0.16-μm long by 2.6 ± 0.08-μm wide, containing a polar filament with 5-7 twists. The spores differ from the species previously described, and phylogenetic analysis based on spore morphology and molecular aspects indicated that the fish parasite Henneguya sp. has a strong trend to form clades mainly based on the environment and host order/family. Thus, we conclude that the species belongs to the family Myxobolidae, genus Henneguya, which comprises a new species: Henneguya paraensis n. sp.

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AbsctractEustrongylides spp. nematodes have birds as final hosts and uses other vertebrates as intermediate/paratenic host (fish, amphibians and reptiles) and have zoonotic potential. In amphibians, the larvae may be located in the subcutaneous tissues, liver and mesentery, between the muscle fibres, especially in the lower limbs. Rhinella marina, which is widely observed in Brazil, has exhibited complex diversity in its helminth fauna, reflecting the unique habitat of the Amazon biome. For the first time, this study describes the morphological aspects of third-stage larvae of Eustrongylides sp. in Rhinella marina from Santa Cruz do Ararí, Marajó Archipelago, Eastern Amazonia, using light and scanning electron microscopy.Keywords: Wild life parasites, helminth of amphibians, nematode larva, Eustrongylides. ResumoOs nematoides do gênero Eustrongylides tem as aves como seus hospedeiros definitivos e utilizam outros vertebrados como hospedeiros intermediários/paratênicos (peixes, anfíbios, répteis), além de apresentar potencial zoonótico. Em anfíbios, as larvas podem estar localizadas em tecidos subcutâneos, fígado, mesentério e entre fibras musculares de membros inferiores. Rhinella marina, anfíbio o qual é distribuído amplamente no Brasil, apresenta uma complexa diversidade em sua helmintofauna, refletindo o seu hábitat no bioma amazônico. O presente estudo descreve, pela primeira vez, os aspectos morfológicos das larvas de terceiro estágio de Eustrongylides sp. em R. marina de Santa Cruz do Arari, Arquipélago do Marajó, Amazônia Oriental Brasileira, utilizando-se microscopia de luz e microscopia eletrônica de varredura.Palavras-chave: Parasitas e animais silvestres, helmintos de anfíbios, larva de nematoide, Eustrongylides.

This study aimed to optimize molecular methods for detecting DNA of Hepatozoon spp. as well as identify the phylogenetic relationships of Hepatozoon strains naturally infecting domestic dogs in Belém, Pará, northern Brazil. Blood samples were collected from 138 dogs, and screened for Hepatozoon spp. using a new nested PCR assay. Positive samples were subjected to genetic characterization based on amplification and sequencing of approximately 670bp of the Hepatozoon spp. 18S rRNA. Of the positive dogs, four shared the haplotype Belém 01, one dog presented the haplotype Belém 02 and two dogs shared the haplotype Belém 03. A Bayesian inference indicates that haplotypes Belém 01 and Belém 02 are phylogenetically related to H. canis, while Belém 03 is related to H. americanum. Overall, based on the first molecular evidence of H. americanum in Brazilian domestic dogs, the proposed protocol may improve the epidemiological investigation of canine hepatozoonosis.

Objective: to investigate Leishmania species in a series of autochthonous cutaneous leishmaniasis (CL) cases in Amapá State, Brazilian Amazon. Methods: this was a descriptive ecological study carried out from January-October/2018 at a reference center for CL diagnosis in Amapá; individuals with CL receiving care from January-May/2018 were recruited; clinical data and skin biopsies were obtained; from extracted DNA (phenol-chloroform) we amplified the hsp70-234 gene region (PCR) for nucleotide sequencing (Applied Biosystems: ABI3500XL). Results: 38 individuals were interviewed, examined and diagnosed; men predominated (28/38; mean age=32.5±11.3); lesions (most ulcers: 37/38) measuring 0,4-10mm (34/38) and ≥11mm (4/38) were multiple in 20/38 individuals; diagnosis of L. braziliensis (1), L. naiffi (1), L. infantum (1), L. (Viannia) sp. (1), L. amazonensis (2) and L. guyanensis (32); individuals infected with L. guyanensis (32/38) lived in 9/10 municipalities represented in the sample, and 17/32 of these had multiple lesions. Conclusion: presence of Leishmania guyanensis predominated and was frequently associated with multiple lesions.

Rhabdias paraensis Santos, Melo, Nascimento, Nascimento, Giese et Furtado, 2011 was described based on fully gravid worms. Further investigations on the free-living stages, immature worms and young individuals were facilitated by cultivation in the laboratory, which allowed us to add new information about the morphology and development of the species. Observations on the free-living development of R. paraensis showed that the life cycle is typical of Rhabdias, with alternation of gonochoristic and hermaphroditic generations and without homogony. Males of the free-living generation were different from those in several species of the genus studied previously. In the original description, the excretory glands and duct were absent in gravid specimens of R. paraensis, while in this study, distinct excretory glands and a duct were observed in immature and young individuals. Additionally, we recognised the separation of the buccal capsule walls into anterior and posterior portions and described the specific shapes of these portions in lateral and apical view. Studies on the morphology and development of free-living stages of Rhabdias spp. from Neotropical regions may provide additional information for species determination.

Nematodes of the genus Rhabdias Stiles & Hassall, 1905 (Rhabditoidea: Rhabdiasidae) have a dioecious free-living stage and a hermaphroditic stage that parasitises the lungs of amphibians and reptiles. Approximately 94 species of Rhabdias have been described. Because the similar morphological characteristics such as the labial structures, the location of the vulva and the shape of the tail of Rhabdias spp. hinder their identification, molecular biology techniques and scanning electron microscopy have been employed to diagnose species of this genus. This study describes Rhabdias breviensis n. sp., parasitic in the lungs of two Neotropical frog species Leptodactylus petersii Steindachner and Leptodactylus macrosternum Miranda-Ribeiro. The description of this species integrates classical taxonomy, scanning electron microscopy and a molecular analysis of the mitochondrial COI gene. The new species differs from all other Rhabdias species parasitic in Neotropical hosts in certain morphometric parameters, the position of the vulva, the host group and the cephalic characters.

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