Report on ticks collected in the Southeast and Mid-West regions of Brazil: analyzing the potential transmission of tick-borne pathogens to man

Specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the Southeast and Mid-West regions of Brazil. Nine species of Amblyommidae were identified: Anocentor nitens, Amblyomma cajennense, Amblyomma ovale, Amblyomma fulvum, Amblyomma striatum, Amblyomma rotundatum, Boophilus microplus, Boophilus annulatus, and Rhipicephalus sanguineus. The potential of these tick species as transmitters of pathogens to man was analyzed. A Flaviviridade Flavivirus was isolated from Amblyomma cajennense specimens collected from a sick capybara (Hydrochaeris hydrochaeris). Amblyomma cajennense is the main transmitter of Rickettsia rickettsii (=R. rickettsi), the causative agent of spotted fever in Brazil. Wild mammals, mainly capybaras and deer, infested by ticks and living in close contact with cattle, horses and dogs, offer the risk of transmission of wild zoonosis to these domestic animals and to man.

Larvicidal effects of endophytic and basidiomycete fungus extracts on Aedes and Anopheles larvae (Diptera, Culicidae)

Introduction In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. Methods The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. Results The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. Conclusions These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts.

HYMENOMYCETES DETERIORADORES DE MADEIRA EM SERRARIAS DE MANAUS, AM, BRASIL

Do levantamento realizado com fungos (Hymenomycetes) deterioradores de madeiras em serrarias de Manaus foram encontradas as seguintes espécies: Coriolopsis occidentalis, Pleurotus ostreatus, Pycnoporus sanguineus e Schizophyllum commune. Pleurotus ostreatus foi assinalada com maior freqüência. As seis espécies de madeiras examinadas Ceiba pentandra(sumaúma), Copaifera multijuga (copaiba), Hura crepitans (assacu), Maquira coriacea (muiratinga), Pseudobombax munguba (munguba) e Virola surinamensis (virola) tiveram suas cascas e alburnos atacados. Hura crepitans foi a que apresentou maior incidência de fungos.

Micromorfologia da degradação de madeira da espécie Amazônica Hura crepitans L. por fungos lignolíticos pertencentes a classe hymenomycetes

Foram estudadas as mudanças micromorfotógicas e químicas que ocorrem na madeira de "açacu" Hura crepitans L. através de vários estágios de deterioração provocada pelos fungos Pycnoporus sanguineus (L.: F.) Murr, Antrodia albida (F.) Donk e Tyromyces sp. coletados nos arredores do município de Manaus, AM, Brasil. O microscópio eletrônico de varredura foi utilizado para a observação da extensão do ataque dos fungos aos diversos elementos xilemáticos de Hura crepitans. A otimização das condições de cultivo para os fungos foi estudada no que diz respeito ao efeito da temperatura e pH no crescimento micelial utilizando diferentes meios de cultura. Os fungos tendem a preferir um ambiente com pH entre 5.0-8.0 sendo o pH 6.0 o ótimo. A temperatura ótima ficou na faixa de 30-35 ºC. Ocorreu a perda progressiva do teor de lignina. Os polissacarídeos são degradados simultaneamente com a lignina, sendo que esta é degradada no estágio inicial com razão superior a dos polissacarídeos especialmente para P. sanguineus e Tyromyces sp. A medida que a lignina é removida, a estrutura fibrilar da celulose na parede celular torna-se evidente. Os elementos de vaso são completamente destruídos no estágio inicial da deterioração. Ocorre o estreitamento da parede celular dos elementos fibrosos adjacentes aos raios com ataque à parede primária e secundária. No estágio mais avançado de deterioração ocorre a destruição dos raios e a formação de cristais (presumivelmente oxalato de cálcio).

Durabilidade natural da madeira de pupunha (Bactris gasipaes Kunth). I. fungos

A durabilidade da madeira de Bactris gasipaes Kunth (pupunha) face aos fungos foi avaliada em ambiente florestal e urbano e em condições de laboratório. Foram utilizadas, cinco árvores com espinhos e cinco sem espinhos da população Tabatinga, raças Putumayo, sendo retirados discos de 25-30cm da base, meio e do topo de cada pupunheira e colocados em uma área florestal próxima ao Banco Ativo de Germoplama de B. gasipaes (2°38'S, 60°03'W). Os discos foram inspecionados trimestralmente, para acompanhar o processo de biodeterioração da madeira causado por fungos durante dezoito meses. No ensaio em ambiente urbano, as amostras do estipe foram distribuídas, uma na posição côncava e outra na convexa, sobre uma estrutura de madeira localizada em uma área próxima da CPPF do Campus do INPA, Manaus e inspecionadas bimestralmente por um ano. Em ambiente florestal, o revestimento dos discos mostrou-se suscetível aos fungos Hymenogramme javanensis Mont. & Berk. e Hypoxylon rubiginosum (Pers.: Fr.) Fr.. Em ambiente urbano, a madeira apresentou alta susceptibilidade a Lenzites striata (Swart.: Fr.) Fr. e a Lenzites sp. e o revestimento a Porostereum amethysteum Hjortst. & Ryv. e a Stereum strigoso-zonatum (Sch.) G. H. Cunn.. Em condições de laboratório, a madeira da pupunheira demonstrou alta resistência aos fungos Lenzites trabea Pers.:Fr., Polyporus fumosus Pers.:Fr. e Pycnoporus sanguineus (L.:Fr.) Murr.

Ectoparasitos de cães e gatos da cidade de Manaus, Amazonas, Brasil

São apresentados resultados da coleta de ectoparasitos em cães e gatos entre agosto de 2001 e maio de 2002 em diferentes bairros da cidade Manaus. No cão foram encontrados: Ctenocephalides f. felis (Bouché, 1835) (Siphonaptera, Pulicidae), Heterodoxus spiniger (Enderlein, 1909)(Phthiraptera, Boopidae), Trichodectes canis (De Geer, 1778) (Phthiraptera, Trichodectidae) e Rhipicephalus sanguineus (Latreille,1806) (Acari, Ixodidae). No gato foi coletado C. f. felis. A prevalência de ectoparasitos foi de 80,8% para cães e 72,7% para gatos. Para a pulga C. f. felis foi de 28,7% para cães e 72,7% para gatos. Para o piolho H. spiniger foi de 12,3% para cães. Para o piolho T. canis foi de 0,1% para cães e para o carrapato R. sanguineus foi de 63% para cães. A média de infestaçãode pulga foi de 1,26 para cães e 1,27 para gatos. A proporção sexual fêmea/macho foi de 1,96:1 no cão e de 3,66:1 no gato. A pulga C. canis (Curtis, 1826), registrada em 1922, não foi coletada.

Ixodidas brasileiros e de alguns paizes limitrophes

The knowledge of the Ixodidae becomes every day, more and more important owing to the fact of the increasing number of diseases of man and animals they can transmit. In Brasil besides transmitting treponemosis, piroplasmosis and anaplasmosis to several domestic animals, the ticks are also responsible fo the transmission of the brazilian rocky mountain spotted fever (A. cajennense and Amblyomma striatum) and they can also harbour the virus of the yellow fever and even to transmit it in laboratory experiments (A. cajennense, O. rostratus). The Brazilian fauna of ticks is a small one and has no more than 45 well-established species belonging to the genus Argas, Ornithodoros, Ixodes, Haemaphysalis, Rhipicephalus, Boophilus, Amblyomma and Spaelaeorhynchus. The genus Amblyomma is the best represented one, with 67% of all species of ticks known in Brazil. One of the most important species in the Amblyomma cajennense owing to its abundance and its wide parasitism in many vertebrates: reptiles, birds and mammals, incluing man, who is much attacked by the larva, the nymph and the adult of this species. The other ticks who attack the man are the Amblyomma brasiliense (the pecari tick), in the forests, and the Ornithodoros, especially the species. O. rostratus and brasiliensis. Other species can bite the man, but only occasionally, like Amblyomma fossum, striatum, oblongogutatum etc. Argas persicus, Rhipicephalus sanguineus and Boophilus are very important species not only as parasites but specially because they transmit several diseases to animals. Some of the ticks of the brazilian wild animals are now also parasites of the domestic ones and vice-versa. Arga persicus var. dissimilis is very common among the poultry and transmits the Treponema anserinum (gallinarum). Boophilus microplus is very abundant on our domestic and wild ruminants (Bos, Cervus, Mazama etc.) and can also ben found on horse, dogs, Felis onca, Felis concolor etc., and it transmits to cattle piroplasmosis and anaplasmosis. Rhipicephalus sanguineus (an introduced species) is now very common on the dog, over all the country. The author recommend to give popular names to some brazilian ticks in order to make them more acquainted with the non scientific people. The author gives a classification of the superfamilia Ixoidoidea and keys to the determination of the different species of brazilian ticks. He creates a new family of Nuttallielidae to the so interesting tick, described by Bedford with the name of Nuttaliella namaqua in South Africa, a new variety of Argas persicus, the Argas persicus var. dissimilis nov. var. owing to the differences on the segment and on the size and morphology of the peritrema. He describes also the female of Amblyomma fuscum Nn. A great part of the author's work deals with the biology, life conditions and parasitism of many of the brazilian ticks in accordance with his personal and from other author's researches, especially in reference to Argas persicus, Ornithodoros rostratus, O. brasiliensis, Boophilus microplus, Rhipicephalus sanguineus, Amblyomma cajennense, A. pseudoconcolor, A. auriculare, A. rotundatum (= A. agamum) etc. The author gives a detailed report upon the parthenogenesis of A. rotundatum (A. agamum) that he first described in 1912 and gives also many references to other species of brazilian ticks, to teratological forms etc. He also gives a detailed report of the geographical distribution of brazilian ticks and of the peculiar conditions of its parasitism. The last part of this article deals with references to the species of ticks of some of the South American Republics namely Argentina, Bolivia, Colombia, Paraguay and Venezuela. Amblyomma testudinis Conil, A. neumanni Ribaga 1902 (= A. furcula Dõnitz 1909) and A. parvitarsum Nn. 1899 (= A. altiplanum Dios 1917), are found only in Argentina. It is given a special bibliography dealing with the brazilian ticks and four text figures and one plate.

Verificação da existencia de uma fase negativa do sangue no periodo prepatente da babesiose canina transmitida por carrapatos

Foram infestados dois cães com carrapatos Rhipicephalus sanguineus infectados pela Babesia canis, tendo sido colocadas 1500 imaqos no primeiro animal e 100 no segundo. Ambos os cães apresentaram infecção das hemácias após o período prepatente de 6 dias. Durante o período prepatente foram diariamente retirados de cada cão 5 ml de sangue, que foram inoculados em 10 cães jovens, por via intravenosa. Os cães inoculados no 1°. 2° e 3° dias do período prepatente permanecerarn negativos. Aqueles inoculados no 4° e 5° dias apresentaram infecção pela babésia. Estes resultados são interpretados, de acordo com os conhecimentos existentes sobre a evolução preeritrocitária dos outros hemosporídeos, como indicadores da existência, no hospedador vertebrado, de uma fase inicial de evolução da babésia em células de tecido, que corresponde a uma fase negativa do sangue e que tem a duração mínima de 3 dias.

Rickettsiae-infected Ticks in an Endemic Area of Spotted Fever in the State of Minas Gerais, Brazil

A study on tick-borne rickettsiosis was developed in the county of Santa Cruz do Escalvado, State of Minas Gerais, Brazil, where a clinical case of the disease, confirmed by necropsy, had been reported. Of the 1,254 ticks collected, 1,061 belonged to the Amblyomma genus, 57 to the Rhipicephalus sanguineus species, 81 to Boophilus microplus, and 46 to Anocentor nitens. The hemolymph test associated with Giménez staining showed that 18 of the 221 A. cajennense specimens, 1 of the 16 R. sanguineus, 1 of the 22 B. microplus, 3 of the A. nitens, and 1 of the A. ovale contained rickettsia-like microorganisms. Only 3 A. cajennense ticks were positive under direct immunofluorescence. A. cajennense was the only species found on humans

A review of the ticks (Acari, Ixodida) of Brazil, their hosts and geographic distribution - 1. The State of Rio Grande do Sul, Southern Brazil

A review of the ticks (Acari, Ixodida) of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. The ticks: Argas miniatus (poultry), Ixodes loricatus (opossums), Amblyomma aureolatum (dogs), A. calcaratum (anteaters), A. cooperi (capybaras), A. nodosum (anteaters), A. tigrinum (dogs) (Neotropical) and Rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, Afrotropical) were confirmed as present, in addition to the predominant, Boophilus microplus (cattle) (introduced, pan-tropical, Oriental). Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations) (Neotropical), Ixodes affinis (deer) (Nearctic/Neotropical) and I. auritulus (birds) (Nearctic/Neotropical/Afrotropical/ Australasian) are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean) are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses)(Nearctic/Neotropical), but still apparent absence of the tropical A. cajennense (catholic) (Nearctic/Neotropical) and the sub-tropical/temperate Ixodes pararicinus (cattle) (Neotropical) in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic"), Old World tick species (B. microplus, R. sanguineus) that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens), as both long established and possibly newly locally introduced species in the state, that should be considered as potential and emergent pests and pathogen vectors to humans and their more recently acquired, introduced domestic animal hosts; rural poultry, dogs and horses.

Screening of Brazilian basidiomycetes for antimicrobial activity

A total of 103 isolates of basidiomycetes, representing 84 species from different Brazilian ecosystems, were evaluated for their antifungal and antibacterial activity in a panel of pathogenic and non-pathogenic microorganisms. Tissue plugs of the fruiting bodies were cultivated in liquid media and the whole culture extracted with ethyl acetate. Crude extracts from Agaricus cf. nigrecentulus, Agrocybe perfecta, Climacodon pulcherrimus, Gloeoporus thelephoroides, Hexagonia hydnoides, Irpex lacteus, Leucoagaricus cf. cinereus, Marasmius cf. bellus, Marasmius sp., Nothopanus hygrophanus, Oudemansiella canarii, Pycnoporus sanguineus, Phellinus sp., and Tyromyces duracinus presented significant activity against one or more of the target microorganisms. Eight isolates were active only against bacteria while three inhibited exclusively the growth of fungi. Two extracts presented wide antimicrobial spectrum and were active against both fungi and bacteria. Differences in the bioactivity of extracts obtained from isolates from the same species were observed.

Ticks, ivermectin, and experimental Chagas disease

Following an infestation of dogticks in kennels housing dogs used for long-term studies of the pathogenesis of Chagas disease, we examined the effect of ivermectin treatment on the dogs, ticks, trypanosome parasites, and also on triatomine vectors of Chagas disease. Ivermectin treatment was highly effective in eliminating the ticks, but showed no apparent effect on the dogs nor on their trypanosome infection. Triatominae fed on the dogs soon after ivermectin treatment showed high mortality, but this effect quickly declined for bugs fed at successive intervals after treatment. In conclusion, although ivermectin treatment may have a transient effect on peridomestic populations of Triatominae, it is not the treatment of choice for this situation. The study also showed that although the dogticks could become infected with Trypanosoma cruzi, this only occurred when feeding on dogs in the acute phase of infection, and there was no evidence of subsequent parasite development in the ticks.

Rickettsia infection in five areas of the state of São Paulo, Brazil

This study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of São Paulo. Eight flea species (Adoratopsylla antiquorum antiquorum, Ctenocephalides felis felis, Polygenis atopus, Polygenis rimatus, Polygenis roberti roberti, Polygenis tripus, Rhopalopsyllus lugubris, and Rhopalopsyllus lutzi lutzi), and five tick species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Ixodes loricatus, and Rhipicephalus sanguineus) were collected from dogs, cats, and opossums. Rickettsia felis was the only rickettsia found infecting fleas, whereas Rickettsia bellii was the only agent infecting ticks, but no animal or human blood was shown to contain rickettsial DNA. Testing animal and human sera by indirect immunofluorescence assay against four rickettsia antigens (R. rickettsii, R. parkeri, R. felis, and R. bellii), some opossum, dog, horse, and human sera reacted to R. rickettsii with titers at least four-fold higher than to the other three rickettsial antigens. These sera were considered to have a predominant antibody response to R. rickettsii. Using the same criteria, opossum, dog, and horse sera showed predominant antibody response to R. parkeri or a very closely related genotype. Our serological results suggest that both R. rickettsii and R. parkeri infected animals and/or humans in the studied areas.

Molecular identification of Rickettsia felis in ticks and fleas from an endemic area for Brazilian Spotted Fever

Rickettsioses are arthropod-borne diseases caused by parasites from the Order Rickettsiales. The most prevalent rickettsial disease in Brazil is Brazilian Spotted Fever (BSF). This work intends the molecular detection of those agents in ectoparasites from an endemic area of BSF in the state of Espírito Santo. A total of 502 ectoparasites, among them Amblyomma cajennense, Amblyomma dubitatum (A. cooperi), Riphicephalus sanguineus, Anocentor nitens and Ctenocephalides felis, was collected from domestic animals and the environment and separated in 152 lots according to the origin. Rickettsia sp. was detected in pools of all collected species by amplification of 17kDa protein-encoding gene fragments. The products of PCR amplification of three samples were sequenced, and Rickettsia felis was identified in R. sanguineus and C. felis. These results confirm the presence of Rickettsia felis in areas previously known as endemic for BSF, disease caused by Rickettsia rickettsii. Moreover, they show the needing of further studies for deeper knowledge of R. felis-spotted fever epidemiology and differentiation of these diseases in Brazil.

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil

During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1%) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100% identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.