Dynamics of cell and tissue genesis in the male reproductive system of ticks (Acari: Ixodidae) Amblyomma cajennese (Fabricius, 1787) and Amblyomma aureolatum (Pallas, 1772): a comparative analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Infecção experimental de Amblyomma spp. (Acari: Ixodidae) com Hepatozoon canis (Apicomplexa: Hepatozoidae) de cães naturalmente infectados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecological aspects of the free-living ticks (Acari: Ixodidae) on animal trails within Atlantic rainforest in south-eastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hepatozoon canis infection associated with dog ticks of rural areas of Rio de Janeiro State, Brazil

Hepatozoon canis is a tick-borne protozoan that infects dogs and has been reported throughout the world. Manifestation of H. canis infection varies from being sub-clinical in apparently healthy dogs to severe illness. The main vector of the infection is the dog tick, Rhipicephalus sanguineus although other species may also transmit this agent. H. canis has been reported previously in Brazil, but mostly as an occasional finding during laboratory exams and always associated with other diseases. The prevalence of H. canis in dogs of rural areas of Brazil has been little studied. For this study, 250 dogs from seven counties of Rio de Janeiro state were examined. All the dogs were from rural areas, near forest. of the dogs examined, 26 dogs were from Seropedica, 82 from Itaguai, 41 from Paracambi, 26 from Mangaratiba, 32 from Barra do Pirai, 32 from Pirai and 11 from Miguel Pereira. Blood smears from the peripheral blood of the ear were taken and ticks found on the dogs were collected for identification in the laboratory. Using blood smear evaluation, H. canis was identified in 39.2% of the animals examined. Other hemoparasites identified were Babesia canis (5.2%) and Ehrlichia canis (4.8%). Four tick species were found parasitizing the dogs: Amblyomma cajennense (23.6%), R. sanguineus (12.4%), Amblyomma aureolatum (2.8%) and Amblyomma ovale (2.0%). There was a positive correlation between the presence of A. cajennense and H. canis infection. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Soroprevalência de Borrelia burgdorferi latu sensu associada à presença de carrapatos em cães de áreas rurais do Estado do Rio de Janeiro, Brasil

Pesquisou-se a presença de anticorpos contra Borrelia burgdorferi latu sensu em cães de áreas rurais de sete municípios do Estado do Rio de Janeiro, pelo ensaio imunoenzimático indireto, associando-se os resultados com a presença de carrapatos nestes animais. de 199 cães examinados, 15,58% estavam positivos, com títulos que variaram de 400 (13,57%) a 1600 (0,5%). Os casos positivos se distribuíram uniformemente nos sete municípios. Não houve diferença estatística (P > 0,05) de soropositivos entre as faixas etárias dos cães acima de seis meses. Carrapatos foram encontrados e coletados em 71 (35,68%) cães, dos quais 24,1% estavam infestados com Amblyomma cajennense, 13,6% com Rhipicephalus sanguineus, 2,5% com Amblyomma aureolatum e 1,5% com Amblyomma ovale. Dos animais soropositivos para B. burgdorferi, 38,7% apresentavam A. cajennense e 22,6% apresentavam R. sanguineus, não havendo, entretanto, correlação positiva entre a presença do carrapato e sorologia positiva.

Morfologia e desenvolvimento do sistema reprodutor masculino de carrapatos do gênero Amblyomma (Acari, Ixodidae): uma análise comparativa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antigen-presenting cells in draining lymph nodes of goats repeatedly infested by the Cayenne tick Amblyomma cajennense nymphs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cutaneous Basophilia in the Resistance of Goats to Amblyomma cajennense Nymphs after Repeated Infestations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Guinea Pigs Develop Cutaneous Basophilia after Repeated Infestations by Nymphs of the Tick Amblyomma triste

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Secretory process of salivary glands of female Amblyomma cajennense (Acari: Ixodidae) ticks fed on resistant rabbits

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological description of Amblyomma brasiliense Aragão, 1908 (Acari: Ixodidae) larvae and nymphs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First record of Amblyomma rotundatum Koch, 1844 (Acari: Ixodidae) parasitizing Paleosuchus palpebrosus Cuvier, 1807 (Reptilia: Crocodylidae), in the western border of Pantanal, Mato Grosso do Sul, Brazil.

This is the first record of Amblyomma rotundatum parasitizing Paleosuchus palpebrosus. This record was made during a herpetofaunal study carried out in high-elevation habitats that are under protection in the mountain range "Serra do Amolar", located in the western border of Brazilian Pantanal, in the state of Mato Grosso do Sul.

Amblyomma triste (Koch, 1844) (Acari : Ixodidae): Morphological description of the ovary and of vitellogenesis

The present study presents the morphology, histology, and the dynamics of vitellogenesis in females of the tick Amblyomma triste. The ovary in this species is of the panoistic type, therefore it lacks nurse cells. It is composed of a layer of epithelial cells that outwardly form the wall of the ovary, but also originate the pedicel, the structure that attaches the oocytes to its external margin, as well the oocytes themselves. In Amblyomma triste, the oocytes develop in four synchronic stages, which differs from the process in other tick species. The classification of the stages of the oocytes was carried out based on the presence of four morphologic characteristics: cytoplasm appearance; site of the germ vesicle; presence, quantity, and constitution of the yolk granules and presence of chorium. (c) 2006 Elsevier B.V. All rights reserved.

Morphological characterization of the ovary and vitellogenesis dynamics in the tick Amblyomma cajennense (Acari : Ixodidae)

In this work we describe the internal morphology of the female reproductive system of the cayenne tick Amblyomma cajennense. This system is represented by a panoistic ovary, which lacks nurse cells in the germarium. This ovary consists of a single tube, in which a large number of oocytes develop asynchronously, thus accompanying the processes of yolk deposition in the oocytes. The oocytes were classified into stages that varied from I to V, according to: cytoplasm appearance, presence of the germ vesicle, presence of yolk granules, and presence of chorion. The study of vitellogenesis dynamics suggest that the yolk elements are deposited in the oocyte following a preferencial sequence, in which the lipids are the first to appear, followed by proteins an finally by the carbohydrates. In this way the yolk of A. cajennense ticks have these three elements that may be free in the cytoplasm or chemically bounded forming glycoprotein or lipoprotein complexes. (C) 2004 Elsevier B.V. All rights reserved.

Amblyomma triste (Koch, 1844) (Acari : Ixodidae) Ovaries: An ultrastructural analysis

This study presents an ultrastructural analysis of the ovary of the tick, Amblyomma triste. The ovary of this species is of the panoistic type that is, without nursing and follicular cells. It is composed of a layer of epithelial cells forming a wall and of germinative cells that generate the oocytes which remain attached to the external margin of this wall by a multicellular pedicel. The different developmental stages in the oocytes had been described by Oliveira et al. [Oliveira, P.R., Bechara, G.H., Camargo-Mathias, M.I., 2006. Amblyomma triste (Koch, 1844) (Acari: Ixodidae): Morphological description of the ovary and of vitellogenesis. Experimental Parasitology 113, 179-185]. The results of the investigation suggest that besides exogenous production of vitellogenic elements, endogenous production can take place simultaneously, contributing to the development and growth of the oocytes. (c) 2007 Elsevier B.V. All rights reserved.