Alessandra Scofield

Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto)

BackgroundUntil recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known.MethodsThe distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens.ResultsFrom the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum.ConclusionOur results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some transition areas. The current distribution of A. cajennense (s.l.) has important implications to public health, since in Brazil A. sculptum is the most important vector of the bacterium Rickettsia rickettsii, the etiological agent of Brazilian spotted fever.

Morphological description of the nymphal stage of Amblyomma geayi and new nymphal records of Amblyomma parkeri

The external morphology of the nymph of Amblyomma geayi Neumann is described by optical and scanning electron microscopy. Unfed nymphs were obtained from an engorged A. geayi female, which had been collected on a sloth (Bradypus variegatus) from Belém municipality, State of Pará, northern Brazil, and was kept under laboratory conditions. With the present description, we propose a modification of a taxonomic key published in 2010 for the Amblyomma nymphs that occur in Brazil, through the inclusion of A. geayi. The nymph of A. geayi is morphologically very similar to the nymph of Amblyomma parkeri Fonseca and Aragão, with only slight morphological differences related to scutal surface and punctuations (more shagreened and less punctuated in A. geayi). These 2 nymphs differ from all other known Amblyomma nymphs from Brazil by the combination of auriculae present as small posterolateral rounded projections, eyes located at the level of the scutal midlength, and a rounded hypostome. These nymphal similarities as well the morphology of the adult stage corroborate previous studies that showed that A. geayi and A. parkeri are genetically closely related. Unpublished host records of the nymphs of both A. geayi and A. parkeri are provided. Established populations of A. geayi and A. parkeri seem to be geographically separated, since all confirmed records of A. geayi are from the northern half of South America (mainly the Amazonian region) and Central America, whereas all known records of A. parkeri are from the Atlantic rainforest biome in northeastern, southeastern, and southern Brazil.

Diagnóstico molecular e frequência de anticorpos anti-Leishmania infantum chagasi em cães do município de Belém, Pará

Visceral leishmaniasis is a disease whose etiological agent in Brazil is Leishmania infantum chagasi. Dogs are considered urban reservoirs of the disease, being an indicator of the human cases occurrence. The present study aimed to diagnose L. infantum chagasi infection in stray and owned dogs in Belem, Para State, by polymerase chain reaction (PCR) and indirect immunofluorescence assay (IFA) using two different antigens. Venous blood samples from adult dogs, regardless of gender or breed, of different neighborhoods in Belem-PA, were collected in tubes with and without anticoagulant to obtain DNA and serum, respectively. These animals were divided into two groups: stray dogs captured by the Center for Zoonosis Control (Group A) and owned dogs (Group B). Sera were analyzed by IFA testing for IgG using two different antigens: 1) Bio-Manguinhos/Fiocruz antigen kit (Ag-PRO) containing promastigotes of Leishmania sp. (Complex Major-Like), 2) Instituto Evandro Chagas Antigen (Ag-AMA) consisting of amastigotes of L. infantum chagasi. The evaluation of the two antigens was performed considering positive the reactions above the 1:80 dilution. Already PCR was performed with DNA isolated from whole blood of animals and amplified with the primers RV1 and RV2. Of the 335 samples analyzed, 10.4% (35/335) were positive by IFA (Ag-PRO) and 0.9% (3/335) with the Ag-AMA. The distribution of positive samples is given as follows: Group A 14.8% (25/169) with Ag-PRO and 1.2% (2/169) with Ag-AMA; Group B 6% (10/166) with Ag-PRO and 0.6% (1/166) with Ag-AMA, being that all samples positive by IFA with Ag-AMA also reacted with Ag-PRO, and none of the samples detected DNA of L. infantum chagasi. The findings of this study indicate that Belem can still be considered non-endemic area for canine visceral leishmaniasis and the nature of the antigen influences the result of the IFA for the detection of anti-L. infantum chagasi antibodies in dogs, and the IFA using promastigotes of Leishmania major-like antigen should be used with caution as a confirmatory diagnostic on epidemiological studies in non-endemic areas.

F200Y polymorphism of the β-tubulin isotype 1 gene in Haemonchus contortus and sheep flock management practices related to anthelmintic resistance in eastern Amazon.

The objective of the present study was to determine the frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene of Haemonchus contortus from various sheep flocks in eastern Amazon, and to identify management practices that may favor the emergence of resistance to anthelmintic drugs in the same area. In total, 305 specimens of H. contortus were collected from sheep at 12 farms located in the state of Pará. An allele-specific PCR was performed to detect the F200Y polymorphism, and questionnaires were used to obtain information about the farms and flocks. All genotypes were detected as follows: 31% of the parasites were RR, 37% of the parasites were SR, and 32% were SS. The completed questionnaires revealed that all farms employed semi-intensive farming systems, performed suppressive anthelmintic treatment, and based their choice of drug on cost and availability rather than on any knowledge regarding drugs that remained effective on their property. It can thus be concluded that the SNP in codon 200 of the β-tubulin isotype 1 gene is present in the H. contortus populations from eastern Amazon, and that a series of management practices that favor the emergence of anthelmintic resistance are employed on these farms.

Infestation by Haematopinus quadripertusus on cattle in São Domingos do Capim, state of Pará, Brazil

Severe infestation with lice was observed on crossbred cattle (Bos taurus indicus ×Bos taurus taurus) in the municipality of São Domingos do Capim, state of Pará, Brazil. Sixty-five animals were inspected and the lice were manually collected, preserved in 70% alcohol and taken to the Animal Parasitology Laboratory, School of Veterinary Medicine, Federal University of Pará, Brazil, for identification. The adult lice were identified as Haematopinus quadripertusus, and all the cattle examined were infested by at least one development stage of this ectoparasite. The specimens collected were located only on the tail in 80% (52/65) of the cattle, while they were around the eyes as well as on the ears and tail in 20% (13/65). Nits, nymphs and adults of the parasite were respectively collected from 98.46% (64/65), 38.46% (25/65) and 23.08% (15/65) of the animals examined. This is the first report of bovine pediculosis caused by H. quadripertusus in the state of Pará, Brazil. Further studies should be conducted to determine the occurrence pattern of this species in Brazil and its importance to livestock production.

First record of notoedric mange in ocelot (Leopardus pardalis Linnaeus, 1758) in the amazon region, Brazil

This paper describes a case of notoedric mange in an ocelot (Leopardus pardalis) in the Brazilian Amazon region. A young male of approximately four months of age that was illegally kept as a pet was apprehended in Altamira, State of Pará, northern Brazil. The animal was transported to the Mangal das Garças Park in the states capital city of Belém. The ocelot had pruritus and lesions suggestive of scabies in the head. Skin scraping material was examined under optic microscopy. There was seen a large number of eggs, larvae, nymphs and adult mites. The mean female and male sizes were 230.2 × 200.4 μm and 137.6 × 104.9 μm. Based on the morphologic characteristics and morphometric analysis, this mite was classified as Notoedres cati. This is the first report of notoedric mange in L. pardalis from Brazilian Amazon.

Trypanosoma cruzi infection in captive Neotropical primates in the Brazilian Amazon

The aim of this study was to detect the infection by Trypanosoma cruzi in captive Neotropical primates in the Brazilian Amazon. From February 2013 to July 2014, 112 blood samples were collected from Neotropical primates from the Amazonas, Amapá, and Pará States, north of Brazil. The subjects belonged to the families Cebidae (N = 59), Atelidae (N = 41), Callitrichidae (N = 5), Pitheciidae (N = 4), and Aotidae (N = 3). Blood smears also were examined for the presence of trypomastigotes by optical microscopy. For the detection of T. cruzi DNA, a Nested‐PCR with primers TCZ1/TCZ2 and TCZ3/TCZ4 was performed. T. cruzi DNA was detected in 12.5% (14/112) of Neotropical primates examined. Positive samples were detected in 16%, 12.5%, and 11.11% of the different species of primates sampled from the Amapá, Pará, and Amazonas states, respectively. The analysis of the blood smears did not reveal trypomastigote forms of T. cruzi. In conclusion, Neotropical primates kept in captivity were infected by T. cruzi in the studied areas. We recommend that a health management protocol be put into place to prevent the transmission of infectious agents among captive populations, captive and wild populations, and between NHPs and the technicians who handle these animals.