Francisco Melo | UFPA - Federal University of Pará (original) (raw)

Papers by Francisco Melo

A new species of nematode, Squamasnema amazonica n. gen. n. sp., is described based on specimens ... more A new species of nematode, Squamasnema amazonica n. gen. n. sp., is described based on specimens foundparasitizing the small intestine of Proechimys roberti (Rodentia: Echimyidae) collected during a surveyof the fauna of Tapirapé-Aquirí National Forest (Brazil, Eastern Brazilian Amazon). The nematodes werefixed and processed for light microscopy and scanning electron microscopy (SEM). These nematodes wereclassified under the family Heligmonellidae and the subfamily Heligmonellinae. Although several speciesin the family Heligmonellidae exhibit discontinuous ridges, Squamasnema n. gen. and Trichotravassosiaare the only genera with columns of scales along their entire body, as an apomorphy of the synlophe.Squamasnema n. gen. has columns of cuticular cells along its body, except for on the left flank, and exhibitsa synlophe with no size gradient or inclination and does not present chitinized structures supporting thesynlophe. Therefore, due to these morphological differences of Squamasnema n. gen., the creation of anew genus was necessary.

A new species of nematode, from the family Spiruridae, is described using parasites from the eso-... more A new species of nematode, from the family Spiruridae, is described using parasites from the eso-phageal mucosa of Proechimys roberti (Rodentia: Echimyidae), which were obtained during a fauna survey in the Tapirapé-Aquirí National Forest, Carajás Reserve, Brazil, Eastern Brazilian Amazon. The helminthes were collected from the esophagus, fixed and processed for light microscopy. Spirura carajaensis n. sp. differs from other species in the genus because it has a left spicule with a well-developed sheath, which is leaf-shaped and covers the terminal half of the spicule. Males and fe-males have a small appendix on the caudal end. This structure has not been reported before for this genus. The present study reports the first record of parasitism by Spirura in rodents of the genus Proechimys in Brazil and in the Amazon biome.

Serpentirhabdias atracti n. sp. is described based on specimens discovered in the lung of Atractu... more Serpentirhabdias atracti n. sp. is
described based on specimens discovered in the lung
of Atractus major Boulenger from Caxiuana˜ National
Forest, Para´, Brazil. The new species is assigned to
Serpentirhabdias Tkach, Kuzmin & Snyder, 2014
based on morphological characters (comparatively
thin body cuticle without prominent inflations,
arrangement of circumoral papillae in two lateral
groups, pre-equatorial position of vulva, eggs in uteri
at early cleavage stages), as well as because of its
parasitism in snakes. The new species is most similar
to S. vellardi (Pereira, 1928) due to the absence of lips
and buccal capsule, similar body dimensions, and the
specificity to dipsadid snakes in Brazil. The two
species differ in the shape of the tail (bulbous
dilatation in the posterior part followed by a threadlike
tail tip present in S. atracti n. sp.), the width of the
oesophagus, and the size of the excretory glands.
Serpentirhabdias atracti n. sp. is the sixth species of
this genus found in the Neotropical Region.

Plagioscion squamosissimus (Heckel 1840), a fish endemic to the Amazon Basin and commonly known a... more Plagioscion squamosissimus (Heckel 1840), a fish endemic to the Amazon Basin and commonly known as the
“silver croaker”, plays an important role in the ecology and economy of Pará State, Brazil. Knowledge of host-parasite
relationships is important to understanding the role of parasites in the control of natural host populations. This work
describes histopathological aspects caused by several common intestinal parasites found during a helminthological
survey of fish in northern Brazil. We observed a high prevalence of helminth infection, especially by J3 nematode
juveniles of the family Anisakidae and metacestodes of the family Protocephalidae (both with 100% prevalence). An
external capsule surrounded each juvenile with numerous juveniles inside sac-like structures formed of connective
tissue. Inflammation was observed to be caused by infection of metacestodes, reaching the intestinal muscularis
mucosa. Neoechinorhynchus veropesoi (38% prevalence) was found in the small intestine of P. squamosissimus
, invading the mucosa, submucosa, and internal muscularis of the intestine causing intense inflammation. Histopathology of
host-parasite relationships in fish has been rare, and the pathology of parasites in P. squamosissimus
is described herein.

Aspidogastreans are commonly found infecting freshwater and marine molluscs, teleosts fishes and... more Aspidogastreans are commonly found infecting freshwater and marine
molluscs, teleosts fishes and freshwater turtles. The subclass comprises four
families – Rugogastridae Schell 1973, Stichocotylidae Faust & Tang 1936,
Multicalycidae Gibson & Chinabut 1984 and Aspidogastridae Poche 1907 – and
it is characterized by the presence of a ventral adhesive disc divided into rows
of alveoli. In the current work, using light and scanning electron microscopy
and molecular approaches, a new species of Aspidogastridae of the genus
Rohdella Gibson & Chinabut, 1984, is described as a parasite of Colomesus psittacus
in Brazil. The new taxon is distinguishable by the presence of oesophageal
glands, teguments covered by ciliated papillae, and the position and shape
of the hermaphroditic duct. The present work describes the third species of
the genus Rohdella, thereby adding new morphological and molecular data
regarding Aspidogastridae.

Journal of Helminthology, Jul 9, 2013

Plagioscion squamosissimus (Heckel, 1840) (Osteichthyes: Sciaenidae) is considered piscivorous an... more Plagioscion squamosissimus (Heckel, 1840) (Osteichthyes: Sciaenidae) is considered piscivorous and is a generalist species endemic to the Amazon region. This fish is an important part of the natural ecosystems in which it occurs and provides basic functional components in the food web. The genus Neoechinorhynchus Stiles & Hassall, 1905 is distributed worldwide and parasitises fish and turtles, but there are few reports of parasites of this genus in South America due to the high diversity of fish that can be found in this region. A new species of thorny headed worm (Acanthocephala: Neoechinorhynchidae) is described from Plagioscion squamosissimus from Guajará Bay, Belém, Pará, Brazil. In general, the unique characteristics of the hooks on the anterior end of the proboscis and the length-to-width ratio relationship separate this new species from other described species in the genus Neoechinorhynchus. Although the species in this genus are mostly found in North America, the dearth of species known from the Neotropics may be due to the lack of studies in this region.

PLoS neglected tropical diseases, 2012

a 4-year-old girl from the town of Oriximiná, Pará state, Brazil, experienced 15 days of nocturna... more a 4-year-old girl from the town of Oriximiná, Pará state, Brazil, experienced 15 days of nocturnal abdominal pain, weight loss, abdominal distension, and the presence of ''white worms'' in the stool, but no diarrhea. At the local hospital, even though a conclusive diagnosis was not available, albendazole was prescribed for 5 days. Following this treatment, worms were still found in the patient's faeces, so the child was taken to the Tropical Medicine Nucleus of the Federal University of Pará (UFPA), where cestode infection was confirmed. This diagnosis was followed by a single oral dose of praziquantel (10 mg/kg).

Acta tropica, 2013

Angiostrongylus cantonensis, the rat lungworm, is one etiological agent of eosinophilic meningoen... more Angiostrongylus cantonensis, the rat lungworm, is one etiological agent of eosinophilic meningoencephalitis in humans. This zoonosis is frequently found in Asia and, more recently, in North America, Caribbean Island and northeastern of South America. Until now, research of A. cantonensis in southern, southeastern and northeastern regions of Brazil has been found natural infections only terrestrial and freshwater intermediate snail hosts (Achatina fulica, Sarasinula marginata, Subulina octona, Bradybaena similaris and Pomacea lineate). In this study, we examined the occurrence of helminthes in the synantropic rodents Rattus rattus and Rattus norvegicus in northern Brazil, focusing on the role of these species as vertebrate hosts of A. cantonensis and A. fulica as intermediate host have found natural. Thirty specimens of R. rattus and twelve of R. norvegicus were collected in the Guamá and Jurunas neighborhoods of the city of Belém, in the Brazilian state of Pará, of which almost 10% harbored adult worms in their pulmonary arteries. Sympatric A. fulica were found to be infected by L3 larvae, which experimental infection confirmed to be A. cantonensis. Natural infection of snails and rodents with A. cantonensis was confirmed through morphological and morphometrical analyses of adults and larvae using light microscopy, scanning electron microscopy and molecular sequences of partial Cytochrome Oxidase subunit I. Phylogenetic analyses showed that A. cantonensis isolated from Pará, Brazil is similar to Japan isolate; once these specimens produced a single haplotype with high bootstrap support with Rio de Janeiro isolate. This study confirms that A. cantonensis is now endemic in northern Brazil, and that R. rattus and R. norvegicus act as natural definitive hosts, and A. fulica as the intermediate host of the parasite in this region.► First record of A. cantonensis in Amazon region. ► Natural infection of R. rattus and R. norvegicus by A. cantonensis. ► Natural infection of A. fulica. ► Experimental infection of R. rattus by A. cantonensis. ► Molecular similarity of A. cantonensis from southeastern and North Region of Brazil.

Parasitology international, 2013

Brasicystis bennetti Thatcher, 1979 was first described from specimens obtained from the subcutan... more Brasicystis bennetti Thatcher, 1979 was first described from specimens obtained from the subcutaneous tissues of the mouth and operculum of Plagioscyion squamosissimus from the Amazon River in Brazil, however since 2008, Brasicystis has been considered a genus inquirendum. This study reviews some of the diagnostic characters from the original description of B. bennetti from the Amazon Delta, and redescribes the genus and species with a discussion of their taxonomic status. Ultrastructural and molecular approaches complement the data presented on this monotypic genus. The diagnosis of the tribe Didymozoini Monticelli, 1888 is amended to incorporate the genus Brasicystis, which is redescribed and revalidated here, with the proposal of an amended key.► Redescription and revalidation of Brasycistis ► New morphological and ultrastructural data for Brasycistis ► Molecular data and phylogeny of Brasicistys bennetti.

Memórias do Instituto Oswaldo Cruz, 2011

The nematode parasites of Rhinella marina include species of the genus Rhabdias (Rhabdiasidae: Rh... more The nematode parasites of Rhinella marina include species of the genus Rhabdias (Rhabdiasidae: Rhabditoidea). The present study describes Rhabdias paraensis sp. nov., which parasitizes the lungs of R. marina in Brazilian Amazonia. Of the more than 70 known species of this genus, 18 are parasites of bufonids, of which, eight are Neotropical. The new species described here is similar to Rhabdias alabialis in the absence of lips is different by the presence of conspicuous cephalic papillae. We describe details of the four rows of pores, which are distributed equally along the whole of the length of the body and connected with hypodermal cells, using histology and scanning electron microscopy. Other histological aspects of the internal structure of this nematode are also described.

Memórias do Instituto Oswaldo Cruz, 2013

Mesocoelium lanfrediae sp. nov. (Digenea: Mesocoeliidae) inhabits the small intestine of Rhinella... more Mesocoelium lanfrediae sp. nov. (Digenea: Mesocoeliidae) inhabits the small intestine of Rhinella marina (Amphibia: Bufonidae) and is described here, with illustrations provided by light, scanning electron microscopy and molecular approachs. M. lanfrediae sp. nov. presents the typical characteristics of the genus, but is morphometrically and morphologically different from the species described previously. The main diagnostic characteristics of M. lanfrediae sp. nov. are (i) seven pairs of regularly-distributed spherical papillae on the oral sucker, (ii) ventral sucker outlined by four pairs of papillae distributed in a uniform pattern and interspersed with numerous spines, which are larger at the posterior margin and (iii) small, rounded tegumentary papillae around the opening of the oral sucker, which are morphologically different from those of the oral sucker itself, some of which are randomly disposed in the ventrolateral tegumentary region of the anterior third of the body. Addionally, based on SSU rDNA, a phylogenetic analysis including Brachycoeliidae and Mesocoeliidae taxa available on GenBank established the close relationship between M. lanfrediae sp. nov. and Mesocoelium sp.

The Journal of parasitology, 2013

Calodium hepaticum (syn. Capillaria hepatica) is a trichurid nematode that parasitizes the hepati... more Calodium hepaticum (syn. Capillaria hepatica) is a trichurid nematode that parasitizes the hepatic parenchyma of
rodents and other mammals. Infections in humans are rare, although they have been reported worldwide. A number
of factors contribute to the distribution of this zoonosis, particularly the presence of dense populations of rodents
associated with relatively poor urban environments, such as those found in parts of the northern Brazilian city of
Belém in the eastern Amazon Basin. This study quantified Calodium infections in commensal synanthropic rodents in
Belém. Rodents were captured in three neighborhoods characterized by poor public sanitation and the city’s highest
incidence of human leptospirosis. A total of 50 rodents were captured (26 Rattus rattus and 24 R. norvegicus), and
23 (10 R. rattus and 13 R. norvegicus) presented macroscopic lesions typical of C. hepaticum. Light microscopy of fresh
samples and histological specimens permitted the identification of larvae and adult specimens containing numerous
eggs with a double-striated shell and bipolar opercula with plugs. This is the first report of C. hepaticum in R. rattus and
R. norvegicus from the Amazon Basin, and it shows a considerable risk of transmission to the local human population.

Lanfrediella amphicirrus gen. nov. sp. nov. Nematotaeniidae (Cestoda: Cyclophyllidea), a tapeworm parasite of Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae), Sep 2011

The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and re... more The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles,
includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra
Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the
difficulties of observing many anatomical traits. This study presents and describes a new genus and species of
nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were
collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed
and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction.
Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes
and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due
to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and
vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied
using Historesin analysis, SEM and 3D reconstruction, and it is the second taxon for which molecular data have
been deposited in GenBank.

Morphological descriptions of Dirofilaria immitis are scarce. For this reason, we carried out mor... more Morphological descriptions of Dirofilaria immitis are scarce. For this reason, we carried out morphologic studies using
both light and scanning electron microscopy for this filaroid species. Morphometric and morphological data were compatible with
previous descriptions of D. immitis, but several anatomical structures are described by scanning electron microscopy for the first time,
such as details of the cuticular striations, positioning of amphids, visualization of anal and vulvar opening, descriptions of deirids,
lateral line, the pair of phasmids in the posterior end in females, and visualization of a small pair of latero-terminals papillae in the
posterior end in males.