Relação carrapato x Tamanduá-bandeira Myrmecophaga tridactyla (Linnaeus 1758) de vida livre: características histológicas e ultra-estruturais da lesão cutânea

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

Detecção sorológica e caracterização moleculares de agentes anaplasmataceae, micoplasmas hemotróficos, piroplasmas e Hepatozoon sp. em carnívoros selvagens mantidos em cativeiro no Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Carrapatos (Acari: Ixodidae) presentes em várias fitofisionomias de uma reserva no cerrado em Uberlândia, Minas Gerais, Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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)

Tests of fed and unfed Amblyomma cajennense ticks (Acari: Ixodidae): first morphological data

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

Action of ethanolic extract from aerial parts of Tagetes patula L. (Asteraceae) on hatchability and embryogenesis of Rhipicephalus sanguineus eggs (Acari: Ixodidae)

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

Coxiella symbiont in the tick Ornithodoros rostratus (Acari: Argasidae)

In the present study, the presence of tick-associated bacteria and protozoa in Ornithodoros rostratus ticks (adults, nymphs, and eggs) from the Pantanal region of Brazil were determined by molecular detection. In these ticks, DNA from protozoa in the genera Babesia and Hepatozoon, and bacteria from the genera Rickettsia, Borrelia, Anaplasma, and Ehrlichia were not detected. Conversely, all tested ticks (100%) yielded PCR products for 3 Coxiella genes (16S rRNA, pyrG, cap). PCR and phylogenetic analysis of 3 amplified genes (16S rRNA, pyrG, cap) demonstrated that the agent infecting O. rostratus ticks was a member of the genus Coxiella. This organism grouped with Coxiella symbionts of other soft tick species (Argasidae), having different isolates of C. burnetii as a sister group, and these 2 groups formed a clade that grouped with another clade containing Coxiella symbionts of hard tick species (Ixodidae). Analysis of tick mitochondrial 16S rRNA gene database composed mostly of tick species previously shown to harbor Coxiella symbionts suggests a phylogenetic congruence of ticks and their Coxiella symbionts. Furthermore, these results suggest a very long period of coevolution between ticks and Coxiella symbionts and indicates that the original infection may have occurred in an ancestor common to the 2 main tick families, Argasidae (soft ticks) and Ixodidae (hard ticks). However, this evolutionary relationship must be confirmed by more extensive testing of additional tick species and expanded populations. (c) 2012 Elsevier GmbH. All rights reserved.

Rickettsia bellii in ticks Amblyomma varium Koch, 1844, from birds in Peru

Amazonian birds were caught and examined for the presence of ectoparasites in the Allpahuayo Mishana National Reserve near Iquitos, Peru, from 13 to 16 August 2011. A total of 40 birds representing 16 species were examined. Two birds (5%) were infested with 2 larvae of Amblyomma varium Koch, 1844, and one nymph of A. calcaratum Neumann, 1899. The 2 larvae of A. varium were infected with Rickettsia bellii. This is the first report of R. bellii in A. varium and also the first record of this rickettsia in Peru. In addition, an immature A. calcaratum is reported from Peru for the first time. (c) 2012 Elsevier GmbH. All rights reserved.

Rickettsial Infection in Ticks (Acari: Ixodidae) Collected on Birds in Southern Brazil

The aim of the study was to evaluate rickettsial infection in ticks from wild birds of the Semidecidual and Atlantic Rainforest remnants of three municipalities of the State of Parana, southern Brazil. Overall, 53 larvae and nymphs collected from birds were checked for the presence of Rickettsia DNA by molecular tests. Five tick species were tested: Amblyomma aureolatum (Pallas), Amblyomma calcaratum Neumann, Amblyomma longirostre (Koch), Amblyomma ovale Koch, and Amblyomma parkeri Fonseca and Aragao. A. longirostre ticks were infected with the spotted fever group agents Rickettsia amblyommii strain AL (32.3% infection rate) and Rickettsia parkeri strain NOD (5.9% infection rate). A new rickettsial genotype was detected in the tick A. parkeri (50% infection rate), which had never been reported to be infected by rickettsiae. Through phylogenetic analysis, this new genotype, here designated as strain ApPR, grouped in a cluster composed by different strains of Rickettsia africae, Rickettsia sibirica, and R. parkeri. We consider strain ApPR to be a new genotype of R. parkeri. This study reports for the first time rickettsial infection in ticks from birds in southern Brazil. The role of migrating birds in the dispersal of these rickettsial strains should be considered in ecological studies of spotted fever group agents in Brazil.

Rickettsial Infection in Ticks Collected from Road-Killed Wild Animals in Rio de Janeiro, Brazil

During 2008D2010, ticks were collected from road-killed wild animals within the Serra dos Orgaos National Park area in the state of Rio de Janeiro, Brazil. In total, 193 tick specimens were collected, including Amblyomma dubitatum Neumann and Amblyomma cajennense (F.) from four Hydrochoerus hydrochaeris (L.), Amblyomma calcaratum Neumann and A. cajennense from four Tamandua tetradactyla (L.), Amblyomma aureolatum (Pallas) and A. cajennense from five Cerdocyon thous L., Amblyomma longirostre (Koch) from one Sphiggurus villosus (Cuvier), Amblyomma varium Koch from three Bradypus variegatus Schinz, and A. cajennense from one Buteogallus meridionalis (Latham). Molecular analyses based on polymerase chain reaction targeting two rickettsial genes (gltA and ompA) on tick DNA extracts showed that 70.6% (12/17) of the A. dubitatum adult ticks, and all Amblyomma sp. nymphal pools collected from capybaras were shown to contain rickettsial DNA, which after DNA sequencing, revealed to be 100% identical to the recently identified Rickettsia sp. strain Pampulha from A. dubitatum ticks collected in the state of Minas Gerais, Brazil. Phylogenetic analysis with concatenated sequences (gltA-ompA) showed that our sequence from A. dubitatum ticks, referred to Rickettsia sp. strain Serra dos Orgaos, segregated under 99% bootstrap support in a same cluster with Old World rickettsiae, namely R. tamurae, R. monacensis, and Rickettsia sp. strain 774e. Because A. dubitatum is known to bite humans, the potential role of Rickettsia sp. strain Serra dos Orgaos as human pathogen must be taken into account, because both R. tamurae and R. monacencis have been reported infecting human beings.

Rickettsia bellii infecting Amblyomma sabanerae ticks in El Salvador

Four Amblyomma sabanerae ticks collected from a turtle (Kinosternon sp.) in San Miguel, El Salvador, were found by molecular analysis to be infected by Rickettsia bellii. We provide the first report of Rickettsia bellii in Central America, and the first report of a Rickettsia species in El Salvador.

Distribution of Rickettsia rickettsii in ovary cells of Rhipicephalus sanguineus (Latreille1806) (Acari: Ixodidae)

Abstract Background Considering the fact that the dog tick, Rhipicephalus sanguineus, has a great potential to become the vector of Brazilian Spotted Fever (BSF) for humans, the present study aimed to describe the distribution of the bacterium Rickettsia rickettsii, the etiological agent of BSF, in different regions of the ovaries of R. sanguineus using histological techniques. The ovaries were obtained from positive females confirmed by the hemolymph test and fed in the nymph stage on guinea pigs inoculated with R. rickettsii. Results The results showed a general distribution of R. rickettsii in the ovary cells, being found in oocytes in all stages of development (I, II, III, IV and V) most commonly in the periphery of the oocyte and also in the cytoplasm of pedicel cells. Conclusions The histological analysis of the ovaries of R. sanguineus infected females confirmed the presence of the bacterium, indicating that the infection can interfere negatively in the process of reproduction of the ticks, once alterations were detected both in the shape and cell structure of the oocytes which contained bacteria.

Natural blood feeding and temperature shift modulate the global transcriptional profile of Rickettsia rickettsii infecting its tick vector

Rickettsia rickettsii is an obligate intracellular tick-borne bacterium that causes Rocky Mountain Spotted Fever (RMSF), the most lethal spotted fever rickettsiosis. When an infected starving tick begins blood feeding from a vertebrate host, R. rickettsii is exposed to a temperature elevation and to components in the blood meal. These two environmental stimuli have been previously associated with the reactivation of rickettsial virulence in ticks, but the factors responsible for this phenotype conversion have not been completely elucidated. Using customized oligonucleotide microarrays and high-throughput microfluidic qRT-PCR, we analyzed the effects of a 10 degrees C temperature elevation and of a blood meal on the transcriptional profile of R. rickettsii infecting the tick Amblyomma aureolatum. This is the first study of the transcriptome of a bacterium in the genus Rickettsia infecting a natural tick vector. Although both stimuli significantly increased bacterial load, blood feeding had a greater effect, modulating five-fold more genes than the temperature upshift. Certain components of the Type IV Secretion System (T4SS) were up-regulated by blood feeding. This suggests that this important bacterial transport system may be utilized to secrete effectors during the tick vector's blood meal. Blood feeding also up-regulated the expression of antioxidant enzymes, which might correspond to an attempt by R. rickettsii to protect itself against the deleterious effects of free radicals produced by fed ticks. The modulated genes identified in this study, including those encoding hypothetical proteins, require further functional analysis and may have potential as future targets for vaccine development.

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

Ticks are classified into three families: Argasidae, Ixodidae, and Nutalliellidae. The taxonomy and phylogeny within Ixodidae are still discussed by the specialists, thus requiring further studies. Amblyomma cajennese and Amblyomma aureolatum (Brazil) belong to two species complexes known as “cajennese” and “ovale”, respectively, and are directly related to the transmission of the Brazilian spotted fever. This confirms the medical and veterinary significance of these species, as well as the need for further morphological studies that will bring a better understanding of their taxonomy, phylogeny, and control. In this context, the present study aimed to characterize the morphology of the male reproductive system of A. cajennese and A. aureolatum when unfed and after 4 days of feeding, thereby seeking to: (a) distinguish the two species or “complexes”, and (b) study an internal system which has the potential to be targeted by acaricides. Therefore, males from both species (unfed and after 4 days of feeding) were cold-anesthetized, dissected, and had their reproductive systems removed for histological analysis. The results showed that the morphology of the male reproductive system is generally similar between both species, like in other Ixodidae ticks, exhibiting a multilobed accessory gland complex related to seminal fluid secretion, a pair of vasa deferentia and a pair of testes housing germ cells (spermatocytes) in different stages. The main differences were found in the development of the accessory gland complex cells and germ cells, showing that the maturation of the male reproductive system starts later in A. aureolatum, when compared to A. cajennese. However, during the blood meal, A. aureolatum development is increased, thus making germ cell maturation and gland complex activity higher than in A. cajennese. This study shows the differences in the development of the male reproductive systems of both species, while providing information that can assist in the establishment of new control methods.

Whole genome analysis of Fusobacterium nucleatum, Rickettsia typhi and Francisella tularensis

The genomes of Fusobacterium nucleatum subspecies polymorphum strain ATCC 10953, Rickettsia typhi strain Wilmington, and Francisella tularensis subspecies holarctica strain OSU18 were sequenced, annotated, and analyzed. Each genome was then compared to the sequenced genomes of closely related bacteria. The genome of F. nucleatum ATCC 10953 was compared to two additional F. nucleatum subspecies, subspecies nucleatum and subspecies vincentii. This analysis revealed substantial evidence of horizontal gene transfer along with considerable genetic diversity within the species of F. nucleatum. R. typhi was compared to R. prowazekii and R. conorii. This analysis uncovered a hotspot for chromosomal rearrangements in the Spotted Fever Group but not the Typhus Group Rickettsia and revealed the close genetic relationship between the Typhus Group rickettsial species. F. tularensis OSU18 was compared to two additional F. tularensis strains. These comparisons uncovered significant chromosomal rearrangements between F. tularensis subspecies due to recombination between insertion sequence elements. ^