Diversity of ticks and detection of Rickettsia amblyommatis infecting ticks on wild birds in anthropogenic landscapes in Bahia state, northeast Brazil.

Birds are important hosts in the maintenance and spread of ticks worldwide, including several species of Amblyomma which harbor rickettsial agents as members of the spotted fever group (SFG). The current survey shows the diversity of tick and rickettsial agents infecting ticks on wild birds from an Atlantic rainforest in the state of Bahia, Brazil. A total of 365 birds were captured, representing two orders, 22 families and 51 species, among which 68 specimens (18.6%) were parasitized. Overall, 132 immature ticks (81 larvae and 51 nymphs) were identified to species level, representing six recognized species of the genus Amblyomma: Amblyomma longirostre (n = 45), Amblyomma nodosum (n = 40), Amblyomma varium (n = 5), Amblyomma parkeri (n = 2), Amblyomma coelebs (n = 3) and Amblyomma calcaratum (n = 1). Amplification by PCR and sequencing of rickettsial genes (gltA and ompA), detected the presence of Rickettsia DNA in 12 (9.1%) of the ticks. Rickettsia amblyommatis was the only agent detected in nine larvae and two nymphs of A. longirostre and one nymph of A. varium with 99-100% similarity.

Detection of "Candidatus Rickettsia wissemanii" in ticks parasitizing bats (Mammalia: Chiroptera) in the northern Brazilian Amazon.

A total of 482 bats representing 32 species and two families were captured in the Amazon forests of the Amapá state in northern Brazil. Nineteen Artibeus planirostris bats (3.9 %) were infested with 160 ticks, all identified as Ornithodoros hasei. Three pools of larvae were screened for rickettsial DNA via polymerase chain reaction (PCR) targeting three rickettsial genes: gltA, ompA and htrA. Only one of them yielded an amplicons of the expected size for all three molecular assays. Comparisons of the obtained sequences including a phylogenetic analysis confirmed the occurrence of "Candidatus Rickettsia wissemanii" in Brazil.

A new species of Amblyomma (Acari: Ixodidae) associated with monkeys and passerines of the Atlantic rainforest biome, Southeastern Brazil.

Recent studies have reported several larvae of an unidentified Amblyomma species on passerine birds in Atlantic rainforest fragments in southeastern Brazil. These larvae yielded a unique 16S rRNA haplotype designated as Amblyomma sp. haplotype Nazaré, which showed nucleotide identity levels of 91% to Amblyomma parkeri Fonseca & Aragão, 1952 and 88% to Amblyomma longirostre (Koch, 1844). Herein, we describe Amblyomma sp. haplotype Nazaré as a new species, Amblyomma romarioi n. sp. Martins, Luz & Labruna, through a formal description of the male and female adult stages. Amblyomma romarioi is morphologically and genetically most closely related to A. parkeri, A. longirostre and Amblyomma geayi Neumann, 1899. Among males, the rectangular basis capituli and rounded coxa I spurs separates A. romarioi from A. parkeri, A. longirostre, and A. geayi, which have basis capituli triangular or slightly hexagonal, and pointed coxa I spurs. Among females, the V-shaped genital aperture and coxa I rounded spurs of A. romarioi contrasts to the U-shaped genital aperture and coxa I pointed spurs in A. parkeri, A. longirostre, and A. geayi. Larvae of A. romarioi have been collected on 24 species of passerines. The few records of nymphs and adults were on the black-fronted titi monkey Callicebus nigrifrons (Spix, 1823). The current distribution of A. romarioi is restricted to the Brazilian Atlantic rainforest, southeastern Brazil, in areas with altitude between 363 and 1600 m, within the distribution of C. nigrifrons. We discuss ecological features of Amblyomma romarioi, comparatively to A. parkeri, A. longirostre and A. geayi. The present study increases the Brazilian tick fauna to 74 species.

Life-cycle of Amblyomma oblongoguttatum (Acari: Ixodidae) under laboratory conditions.

This study evaluated for the first time the life cycle of Amblyomma oblongoguttatum in the laboratory. For this purpose, larvae and nymphs were exposed to Gallus gallus (chicks), Rattus norvegicus (wistar rat), Calomys callosus (vesper mouse), Oryctolagus cuniculus (domestic rabbit), Cavia porcellus (guinea pig), and Didelphis albiventris (white-eared opossum). Nymphs were exposed to G. gallus, C. callosus, C. porcellus, O. cuniculus, R. norvegicus, and Nectomys squamipes (water rat). Adult ticks were exposed to domestic dogs. The life-cycle of A. oblongoguttatum in the laboratory could be completed in an average period of 188 days, considering prefeeding periods of 25 days for each of the parasitic stages. Under laboratory conditions, none of the host species was highly suitable for A. oblongoguttatum larvae, since the recovery rates of engorged larvae were always <15%, or most of the times ≤5%. Similar results were obtained for nymphs, with recovery rates of engorged nymphs always <6%. Our results, coupled with literature data, suggest that small mammals, especially small rodents, do not have an important role in the life-cycle of A. oblongoguttatum under field conditions. Domestic dogs showed to be highly suitable for the adult stage of A. oblongoguttatum, in agreement with literature data that have appointed dogs as important hosts for the adult stage of A. oblongoguttatum in South America.

Infection of Amblyomma ovale with Rickettsia species Atlantic rainforest in Serra do Mar, São Paulo State, Brazil.

Rickettsia rickettsii and Rickettsia sp. strain Atlantic rainforest, that is considered to represent a genetic variant of Rickettsia parkeri, are confirmed as being capable of infecting humans in Brazil. This study reports the detection and characterization, by PCR and nucleotide sequencing, of Rickettsia sp. strain Atlantic rain forest in Amblyomma ovale parasitizing a human, in ticks infesting dogs and in free-living ticks collected from the environment where the human infestation was recorded. The data contribute to our knowledge of infection rates in A. ovale with Rickettsia sp. strain Atlantic rainforest and identified an additional location in the state of São Paulo populated with ticks infected with this emerging pathogen.

Additional information about a mange outbreak by Allopsoroptoides galli (Acari: Psoroptoididae) in commercial laying hens in the state of São Paulo, Brazil / Informação adicional sobre um surto de sarna causado por Allopsoroptoides galli (Acari: Psoroptoididae) em uma granja de poedeiras no Estado de São Paulo

This paper reports additional information about a mange outbreak by the mite Allopsoroptoides galli in a commercial egg-laying hen facility in the state of São Paulo, Brazil. About half of the 76,000 multi-age birds of the flock were affected. Experimental infestations carried out on naive hens resulted in clinical signs similar to those diagnosed in naturally infested hens, such as generalized scaly dermatitis, presence of mucus-like material and yellowish crusts on the skin and around the calami, feather loss and strong unpleasant odor. About 30% drop of egg production was estimated. The possible source of infestation were wild birds identified on the ground and roofs of the sheds...

Este artigo acrescenta informações adicionais sobre um surto de sarna causado por Allopsoroptoides galli em uma instalação comercial de galinhas de postura no estado de São Paulo, Brasil. Approximadamente metade das 76.000 aves, com várias idades, mantidas em uma granja, foram infestadas. Um total de 12 galinhas sem prévio contato com os ácaros e infestadas experimentalmente apresentaram sinais clínicos semelhantes aos diagnosticados em galinhas naturalmente infestadas, tais como dermatite escamosa generalizada, presença de material mucoso, crostas amareladas na pele e em torno dos câlamos, perda de penas e forte odor desagradável. A perda na produçãode ovos foi estimada em 30%. As possíveis fontes de infestação foram aves silvestres observadas no chão próximo aos galpões e telhados...

Description of larva of Amblyomma romitii (Acari: Ixodidae) by optical and scanning electron microscopy, including porotaxy and phylogenetic analysis.

The description of the larva of Amblyomma romitii Tonelli-Rondelli is based on optical and scanning electron microscopy. Larvae were obtained under laboratory conditions from an engorged female collected on capybara from Rurópolis municipality, State of Pará, Northern Brazil. Several characters are presented including the chaetotaxy of idiosoma, palpi and Haller's organ. The larval porotaxy (topographical and numerical patterns of integumentary structures) was presented and compared to that of the other Amblyomma spp. larvae. The mitochondrial 16S rDNA partial sequence of A. romitii generated in the present study was aligned with sequences previously determined for other Amblyomma species available in Genbank and with some species presently sequenced. The larval morphology of A. romitii and other Neotropical Amblyomma spp. larvae is discussed as well as the DNA sequence and its phylogenetic position among other species of the genus.

Serological identification of house dust mite allergens in dogs with atopic dermatitis / Identificação sorológica de alérgenos de ácaros da poeira domiciliar em cães com dermatite atópica

House dust mite antigens have been used for decades to diagnose allergic diseases in humans and animals. The objective of this study was to identify allergens in commercial Dermatophagoides farinae and Blomia tropicalis extracts by immunoblotting using sera from allergic dogs and anti-dog IgE conjugate. The analysis of antigens present in the D. farinae extract (FDA Allergenic) using sera from 10 dogs allergic to D. farinae showed that eight sera recognized a band of approximately 102 kDa, eight recognized two bands of 52 to 76 kDa, five recognized one band of approximately 76 kDa, four recognized one band of 31 to 38 kDa, and two recognized one band of 12 to 17 kDa. Immunoblot assays of the B. tropicalis extract (FDA Allergenic) using sera from 10 animals allergic to B. tropicalis showed that five sera recognized two bands of 52 to 76 kDa. These results demonstrate the importance of the two house dust mite species for the pathogenesis of canine atopic dermatitis in Brazil. In addition, the results indicate which allergens should be present in allergenic extracts used for diagnosis and allergen-specific immunotherapy.

Antígenos de ácaros da poeira domiciliar são utilizados por décadas para diagnóstico de doenças alérgicas em seres humanos e animais. O objetivo do presente trabalho foi identificar proteínas alergênicas presentes em extratos de Dermatophagoides farinae e Blomia tropicalis através de "immunoblotting" utilizando-se soros de animais alérgicos e conjugado anti-IgE canina. A análise por "immunoblotting" dos antígenos presentes no extrato de D. farinae (FDA Allergenic), utilizando soros de dez animais alérgicos, mostrou que oito soros reconhecem uma banda com peso molecular de aproximadamente 102 kDa; oito soros duas bandas entre 52 e 76 kDa; cinco soros uma banda com aproximadamente 76 kDa; quatro soros uma banda entre 31 e 38 kDa; e dois soros uma banda entre 12 e 17 kDa. A análise por "immunoblotting" dos antígenos do extrato de B. tropicalis (FDA Allergenic) mostrou que cinco soros reconhecem duas bandas com pesos moleculares entre 52 e 76 kDa. Esses resultados demonstram a importância dessas duas espécies de ácaros da poeira domiciliar na patogênese da dermatite atópica canina no Brasil, assim como indicam alérgenos que devem estar presentes nos extratos alergênicos utilizados para diagnóstico e imunoterapia alérgeno-específica.

Associação entre Mycoplasma spp. e ácaros do conduto auditivo de bovinos / Mycoplasmas species associated with the ear mites in cattle

Esse estudo foi realizado com o objetivo de verificar a associação entre micoplasmas e ácaros (Raillietia auris e R. flechtmanni) no conduto auditivo de bovinos. Foram realizadas lavagens no conduto auditivo externo de 60 bovinos abatidos no Estado do Rio de Janeiro, Brasil. Para a lavagem dos condutos auditivos foi utilizada solução salina tamponada (PBS, pH 7.2) em seringas estéreis de 60mL. Para o isolamento de micoplasmas foram utilizados pools de ácaros por animal, lavados sucessivamente em 1mL de meio Hayflick modificado. Os lavados dos ácaros foram diluídos de 10-1 até 10-5 e repicados em meio Hayflick modificado, sólido e líquido e incubados a 37°C por 48-72 horas em microaerofilia. A identificação das espécies de micoplasmas foi realizada pelo teste da imunoperoxidase indireta (IPI). Verificou-se alta prevalência de ácaros do gênero Raillietia spp. 76,7% (46/60). O parasitismo por ácaros e micoplasmas foi verificado em 40 animais (74,1%), sendo esta associação significativa (p<0,001). Dos ácaros processados para isolamento de micoplasmas, 193 foram fêmeas e 25 machos. A frequência de Mycoplasma em Raillietia spp. foi de 81,2% (177/218) (p<0.001). Das fêmeas identificadas, 52,3% (101/193) foram R. auris e 47,7% (92/193) R. flechtmanni. A frequência de Mycoplasma nas fêmeas de R. auris foi de 75,2% (76/101) e na espécie R. flechtmanni foi de 88% (81/92) (P<0.05). As espécies de micoplasmas tipificadas pela IPI nos ácaros Raillietia auris foram: M. alkalescens 6,9%, M. arginini 3,4%, M. bovirhinis 9,2%, M. conjunctivae 18,4%, M. mycoides mycoides LC 8,0%, M. capricolum 5,7%. Em R. flechtmanni as espécies de micoplasmas identificadas foram: M. alkalescens 12,2%, M. arginini 1,0%, M. bovirhinis 18,9%, M. bovis 2,2%, M. conjunctivae 21,0%, M. mycoides mycoides LC 11,0% e M. capricolum 4,4%. As espécies de micoplasmas identificadas no conduto auditivo externo dos bovinos foram as mesmas presentes nos ácaros R. auris e R. flechtmanni. Os resultados confirmam que o conduto auditivo externo de bovinos é um habitat de Mycoplasma spp., incluindo espécies potencialmente patogênicas para os rebanhos, além dos ácaros R. auris e R. flechtmanni estarem associados com esses molicutes carreando-os em seu organismo.

This study was carried out to assess the association between of mycoplasmas species with ear mites Raillietia auris and R. flechtmanni in the external ear canal of 60 bovines at slaughter time from the State of Rio de Janeiro, Brazil. Steril syringes (60ml) loaded with buffer solution (PBS, pH 7.2) were used for the ear canal flushing. Were processed 218 mites for mycoplasma isolation. A pool of mites from each sampled bovine was washed five times sucessively in 1mL of liquid modified Hayflick´s medium. The washed mites obtained were diluted up to 10-1 at 10-5, inoculated in liquid and solid Hayflick´s media and incubated at 37ºC for 2-3 days, being the plates put into jar for the obtention of microaerofilia condition. The Typical colonies were typified by the indirect imunoperoxidase test (IPI) with paper discs satured with hyperimmune rabbit sera. In the studied bovine high prevalence was verified Raillietia spp. 76.7% (46/60). The parasitism by mycoplasmas and mites was verified in 40 animals (74.1%), this association was significant (p<0.001). Among the mites processed for isolation mycoplasmas 193 were female and 25 males. The frequency of Mycoplasma in Raillietia spp. was of 81.2% (177/218) (p<0.001). Of the females identified 52.3% (101/193) were R. auris and 47.7% (92/193) were R. flechtmanni. The frequency of Mycoplasma in the females of R. auris was of 75.2% (76/101) and 88% (81/92) in R. flechtmanni (P<0.05). The mycoplasmas species typified by IPI in the Raillietia auris mites were M. alkalescens 6.9%, M. arginini 3.4%, M. bovirhinis 9.2%, M. conjunctivae 18.4%, M. mycoides mycoides LC 8.0%, M. capricolum 5.7%. In the R. flechtmanni mites mycoplasmas species typified were M. alkalescens 12.2%, M. arginini 1.0%, M. bovirhinis 18.9%, M. bovis 2.2%, M. conjunctivae 21.0%, M. mycoides mycoides LC 11.0% e M. capricolum 4.4%. The species of identified mycoplasmas in the external ear canal bovine and mites were exactly the same. The results confirm that the external ear canal cattle's ear canal is also a mycoplasmas source, including potentially pathogenic species for cattle, and these mollicutes are closely related with mites Raillietia spp. that is carrier and this agent in your organism.

Experimental infection of Rhipicephalus sanguineus ticks with the bacterium Rickettsia rickettsii, using experimentally infected dogs.

We evaluated if Rickettsia rickettsii-experimentally infected dogs could serve as amplifier hosts for hipicephalus sanguineus ticks. In addition, we checked if Rh. sanguineus ticks that acquired Ri. rickettsii from dogs could transmit the bacterium to susceptible hosts (vector competence), and if these ticks could maintain the bacterium by transstadial and transovarial transmissions. Uninfected larvae, nymphs, and adults of Rh. sanguineus were allowed to feed upon three groups of dogs: groups 1 (G1) and 2 (G2) composed of Ri. rickettsii-infected dogs, infected intraperitoneally and via tick bites, respectively, and group 3 composed of uninfected dogs. After larval and nymphal feeding on rickettsemic dogs, 7.1-15.2% and 35.8-37.9% of the molted nymphs and adults, respectively, were shown by polymerase chain reaction (PCR) to be infected by Ri. rickettsii, confirming that both G1 and G2 dogs were efficient sources of rickettsial infection (amplifier host), resulting in transstadial transmission of the agent. These infected nymphs and adults successfully transmitted Ri. rickettsii to guinea pigs, confirming vector competence after acquisition of the infection from rickettsemic dogs. Transovarial transmission of Ri. rickettsii was observed in engorged females that had been infected as nymphs by feeding on both G1 and G2 dogs, but not in engorged females that acquired the infection during adult feeding on these same dogs. In the first case, filial infection rates were generally <50%. No tick exposed to G3 dogs was infected by rickettsiae in this study. No substantial mortality difference was observed between Ri. rickettsii-infected tick groups (G1 and G2) and uninfected tick group (G3). Our results indicate that dogs can be amplifier hosts of Ri. rickettsii for Rh. sanguineus, although only a minority of immature ticks (<45%) should become infected. It appears that Rh. sanguineus, in the absence of horizontal transmission, would not maintain Ri. rickettsii through successive generations, possibly because of low filial infection rates.

The life cycle of Amblyomma auricularium (Acari: Ixodidae) using rabbits (Oryctolagus cuniculus) as experimental host.

The life cycle of Amblyomma auricularium (Conil) is reported for the first time, using rabbits as experimental host. Developmental periods of free-living stages were observed in an incubator at 27 +/- 1 degrees C, 80 +/- 10% RH and 24 h darkness. The complete life cycle, including pre-feeding periods for each parasitic stage, ranged from 97 to 162 days. The overall sex ratio was 1.16:1 (M:F). Feeding and premolt periods, molting success, and engorgement weight of nymphs were statistically different between males and females (P < 0.01), but because their ranges overlapped, they cannot be used to predict the sex with accuracy. The potential role of rabbits as experimental hosts for rearing A. auricularium in the laboratory is discussed.

Experimental infection of the rabbit tick, Haemaphysalis leporispalustris, with the bacterium Rickettsia rickettsii, and comparative biology of infected and uninfected tick lineages.

The present study consisted of two experiments that evaluated experimental infections of Haemaphysalis leporispalustris ticks by a Brazilian strain of Rickettsia rickettsii, and their effect on tick biology. In experiment I, ticks were exposed to R. rickettsii during the larval, nymphal or adult stages by feeding on rabbits (Oryctolagus cuniculus) needle-inoculated with R. rickettsii, and thereafter reared on uninfected rabbits for the entire next tick generation. Regardless of the tick stage that acquired the infection, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 1.3 to 41.7%), and were able to transmit R. rickettsii to uninfected rabbits, as demonstrated by rabbit seroconversion, guinea pig inoculation with rabbit blood, and PCR on rabbit blood. In Experiment II, ticks were exposed to R. rickettsii during the larval stage by feeding on rabbits co-infested with R. rickettsii-infected adult ticks, and thereafter reared on uninfected rabbits until the next generation of larvae. Again, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 3.0 to 40.0%), and were able to transmit R. rickettsii to uninfected rabbits. Thus, it was demonstrated that larvae, nymphs, and adults of H. leporispalustris were able to acquire and maintain the R. rickettsii infection by transstadial and transovarial transmissions within the tick population, with active transmission of the bacterium to susceptible rabbits by all parasitic stages. Analyses of biological parameters of uninfected and R. rickettsii-infected tick lineages were performed in order to evaluate possible deleterious effects of R. rickettsii to the infected tick lineages. Surprisingly, all but one of the four R. rickettsii-experimental groups of the present study showed overall better biological performance than their sibling uninfected control ticks. Results of the present study showed that H. leporispalustris could support infection by a high virulent strain of R. rickettsii for at least two generations, in which infected tick lineages tended to have better performance than uninfected ticks. Our results support a possible role of H. leporispalustris in the enzootic maintenance of R. rickettsii in Latin America, as previously suggested by earlier works.

Raillietia caprae (Acari: Raillietidae) and Psoroptes ovis (Acari: Psoroptidae) in the ears of goats in the state of Rio de Janeiro, Southeast Brazil.

Ear canals of 145 domestic goats including the breeds Saanen, Toggenburg, Anglobian, Alpine, Moxoto (native) and crossbred goats from 10 smallholder farms were examined by flushing for the presence of ear mites. Prevalence of Raillietia caprae Quintero, Bassols and Acevedo, 1980 was much more higher than Psoroptes ovis (Hering, 1838) in the studied area, respectively 62% (90/145) and 4% (6/145). The youngest animal parasitized was eight months old and the oldest was 10 years old. Subclinical otitis is a common feature of infestation by both species but increase of wax and the presence of pus were detected in the flushed material in approximately 10% of the goats examined.

The effect of temperature and fasting period on the viability of free-living females of Rhipicephalus sanguineus (Acari: Ixodidae) under laboratory conditions.

Little is known about the effect of temperature on viability of free-living phases of the life cycle of Rhipicephalus sanguineus (Latreille, 1806) despite of its importance as vector of several pathogens. Knowledge of the effect of abiotic factors on the capacity of a given tick species to infest new hosts is important for routine experimental activities under laboratory conditions, and may be relevant to understand the transmission of pathogens. The study evaluates the viability of R. sanguineus females held at 18 +/- 1, 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH (saturation deficits of 3.0, 5.3 and 7.2 mmHg, respectively) for three fasting periods (3 and 20 days and the day when female mortality reached approximately 50% after ecdysis), under laboratory conditions. In general, the best result on viability was obtained when rabbits were infested with unfed female ticks after three or 20 fasting days at both 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH.

Spatial distribution and impact of cattle-raising on ticks in the Pantanal region of Brazil by using the CO(2) tick trap.

This study evaluates the impact of cattle-raising on ticks associated with wildlife in the Pantanal region of Brazil, by trapping free-living ticks using a CO(2) tick trap. The traps were equally distributed in two areas: a 600-ha protected area (PA) and the Nhumirim Ranch (NR). Both areas are contiguous and located at the sub-region of Nhecolândia (18 degrees 59'S; 56 degrees 39'W), Pantanal, Brazil. In each area, four habitat types were selected: cerrado (tropical savanna), forest patches, lakes and soda lakes. The last two are temporary lagoons of fresh and salted water, respectively. A total of 980 nymphs, 613 adults and 13 larvae of ticks Amblyomma were collected in 256 h of collection. In a pen of calves infested by Ornithodoros rostratus 114 specimens were collected, including larvae, nymphs and adults. Adults of A. cajennense and A. parvum were more abundant in the savanna at NR, but not differed among habitat types at PA. There was a tendency of having more nymphs in NR than in PA. The higher number of ticks found in the NR in comparison to the PA is not due to the presence of cattle itself but probably due to introduced dogs and horses, habitat alteration.

Raillietia caprae (Acari: Raillietidae) and Psoroptes ovis (Acari: Psoroptidae) in the ears of goats in the state of Rio de Janeiro, Southeast Brazil / Raillietia caprae (Acari: Raillietidae) e Psoroptes ovis (Acari: Psoroptidae) nos condutos auditivos de caprinos no Estado do Rio de Janeiro, Brasil

Ear cannals of 145 domestic goats including the breeds Saanen, Toggenburg, Anglobian, Alpine, Moxoto (native) and crossbred goats from 10 smallholder farms were examined by flushing for the presence of ear mites. Prevalence of Raillietia caprae Quintero, Bassols and Acevedo, 1980 was much more higher than Psoroptes ovis (Hering, 1838) in the studied area, respectively 62 percent ( 90/145) and 4 percent ( 6/145). The youngest animal parasitized was eight months old and the oldest was 10 years old. Subclinical otitis is a common feature of infestation by both species but increase of wax and the presence of pus were detected in the flushed material in approximately 10 percent of the goats examined.

Os condutos auditivos de 145 caprinos das raças Saanen, Toggenburg, Anglobian, Alpine, Moxoto (native) e mestiços provenientes de 10 pequenos criadores foram examinados pela técnica de lavagem para diagnosticar a infestação por ácaros. A prevalência de Raillietia caprae Quintero, Bassols and Acevedo, 1980 foi muito mais alta do que Psoroptes ovis (Hering, 1838) - 62 por cento (90/145) e 4 por cento (6/145), respectivamente. O animal parasitado mais jovem tinha oito meses de idade e o mais velho 10 anos. Otite subclínica é comum nas infestações por ambas espécies mas aumento de cerume e presença de pus foram diagnosticados no material da lavagem em aproximadamente 10 por cento dos caprinos examinados.

Influência do comportamento gregário nos processos de muda de Rhipicephalus sanguineus (Latreille, 1806) (acari: ixodidae), em condições laboratoriais / Influence of aggregation on the molting process of Rhipicephalus sanguineus, (Latreille, 1806) (acari: ixodidae) under laboratory conditions

Objetivou-se com o experimento verificar a influência de diferentes agregações sobre os parâmetros relacionados ao processo de ecdise ninfal e de adulto de Rhipicephalus sanguineus (Latreille, 1806). Foram utilizados como hospedeiros 10 coelhos domésticos (Oryctolagus cuniculus) primos-infestados. Foram analisados os períodos de pré-ecdise, de ecdise e de muda, o percentual e o ritmo de ecdise para todos os estágios estudados. Durante toda a fase não-parasitária, os carrapatos foram mantidos em condições controladas de umidade (80±5 por cento) e temperatura (27±1ºC). Um total de 1560 larvas ingurgitadas e de 1560 ninfas ingurgitadas foi utilizado. Os carrapatos foram divididos em seis grupos contendo um, cinco, dez, 20, 40 e 80 espécimes cada. Para cada um desses grupos foram realizadas dez repetições. Os processos de ecdise ninfal e de adulto foram acompanhados diariamente. Após a análise dos resultados, verificou-se que não houve relação entre as diferentes agregações e o percentual de ecdise em nenhuma etapa experimental. Em todos os outros parâmetros biológicos estudados, verificaram-se diferenças significativas (p<0,05). Os resultados obtidos sugerem que em elevadas agregações o processo de ecdise tende a ser mais rápido.

The objective of this experiment was to evaluate the influence of different aggregations on the molting process of Rhipicephalus sanguineus (Latreille, 1806). Tick-naïve domestic rabbits (Oryctolagus cuniculus) were used as experimental hosts for the parasitic phase. A total of 10 rabbits were used on the experiment. All tick free-living phases were kept in incubator at 27±1ºC, 80±5 percent relative humidity and scotophase. The periods of pre-molt, molt, percentage of ecdisis and molt rhythm of larvae and nymphs were studied. A total of 1560 engorged larvae and 1560 nymphs of R. sanguineus were divided in six groups of aggregations: 1, 5, 10, 20, 40 and 80 ticks with ten repetitions each one. The ecdises of nymphs and adults were daily observed. The percentage of ecdysis was the only parameter with no aggregations effects. All others parameters were statistically different (p<0,05). The results suggested that highest aggregations accelerate the molting process.

Evaluation of skin sensitivity in dogs bearing allergic dermatitis to standardized allergenic extract of house dust and storage mites

The objective of the study was to evaluate whether allergenic extracts of five house dust and storage mite species standardized for humans might be used for the diagnosis of canine atopic dermatitis (CAD). Extracts of Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) and Tyrophagus putrescentiae (Acaridae) were evaluated by intradermal testing in 20 healthy dogs (control) and 25 dogs with allergic dermatitis. A significant difference in the response was observed between the two groups (p<0.05). Only one dog (5 percent) in the control group reacted to the intradermal test, whereas 14 dogs (56 percent) in the allergic group were positive for at least one extract (odds ratio = 24.2). Most of the positive reactions observed in the allergic group occurred against the extracts of T. putrescentiae or L. destructor, each inducing reactions in 10 dogs (40 percent). D. farinae, D. pteronyssinus e B. tropicalis extracts induced reactions in 7 (28 percent), 3 (12 percent) and 3 (12 percent) dogs, respectively. The allergenic extracts standardized for humans evaluated in the present study may be used as a tool to complement the diagnosis of the disease, as well as to select potential allergen candidates for allergen-specific immunotherapy.

O presente trabalho teve como objetivo avaliar se extratos alergênicos de cinco espécies de ácaros da poeira domiciliar e produtos armazenados, padronizados para humanos, podem ser utilizados no diagnóstico da dermatite atópica canina. Extratos de Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) e Tyrophagus putrescentiae (Acaridae) foram avaliados através de testes intradérmicos em 45 cães, dos quais 20 normais e 25 com dermatite alérgica. Uma diferença significativa foi observada no padrão de respostas obtidas dos dois grupos (p<0.05). Apenas um animal (5 por cento) do grupo controle reagiu ao teste cutâneo, enquanto que no grupo dos alérgicos 14 cães (56 por cento) apresentaram pelo menos uma reação positiva (odds ratio = 24.2). As maiores freqüências de reações positivas observadas no grupo dos alérgicos foram aos extratos de T. putres-centiae ou L. destructor, cada um induzindo reações em 10(40 por cento) cães. Os extratos de D. farinae, D. pteronyssinus e B. tropicalis foram responsáveis por reações positivas em 7(28 por cento), 3(12 por cento) e 3(12 por cento) cães, respectivamente. Os extratos padronizados para humanos avaliados no presente estudo podem ser utilizados como complemento no diagnóstico da doença, assim como na seleção de alérgenos para a imunoterapia alérgeno-específica.

[Influence of aggregation on the molting process of Haemaphysalis leporispalustris (Acari: Ixodidae) under laboratory conditions]. / Influência do comportamento gregário nos processos de muda de Haemaphysalis leporispalustris (Acari: Ixodidae) em condições laboratoriais.

The aim of the experiment was to evaluate the influence of different aggregations on the molting process of the nidicoulus ticks, Haemaphysalis leporispalustris. Tick-naïve domestic rabbits (Oryctolagus cuniculus) were used as experimental hosts for the parasitic phase. All free-living phases were kept into 4.5 mL glass vials in incubators at 27+/-1 degrees C, 80+/-15% relative humidity and scotophase. The periods of pre-molt, molt, percentage of ecdisis and molting pattern of larvae and nymphs were studied. A total of 1560 engorged larvae and nymphs were divided in six groups of aggregations: 1, 5, 10, 20, 40 and 80 ticks with ten repetitions. The molting of nymphs and adults were observed daily. The percentage of ecdysis was the only parameter with no statistical difference among the groups (p>0.05). All others parameters were statisticaly different (p<0.05). The results suggested that highest aggregations accelerate the molting process of H. leporispalustris. We recommended the following aggregations: 4.4 ticks/ml for scientific research and less than 7.7 tick/ml for ticks maintenance.

[Influence of aggregation on the molting process of Rhipicephalus sanguineus, (Latreille, 1806) (Acari: Ixodidae) under laboratory conditions]. / Influência do comportamento gregário nos processos de muda de Rhipicephalus sanguineus (latreille, 1806) (acari: ixodidae), em condições laboratoriais.

The objective of this experiment was to evaluate the influence of different aggregations on the molting process of Rhipicephalus sanguineus (Latreille, 1806). Tick-naïve domestic rabbits (Oryctolagus cuniculus) were used as experimental hosts for the parasitic phase. A total of 10 rabbits were used on the experiment. All tick free-living phases were kept in incubator at 27+/-1 degrees C, 80+/-5% relative humidity and scotophase. The periods of pre-molt, molt, percentage of ecdisis and molt rhythm of larvae and nymphs were studied. A total of 1560 engorged larvae and 1560 nymphs of R. sanguineus were divided in six groups of aggregations: 1, 5, 10, 20, 40 and 80 ticks with ten repetitions each one. The ecdises of nymphs and adults were daily observed. The percentage of ecdysis was the only parameter with no aggregations effects. All others parameters were statistically different (p<0,05). The results suggested that highest aggregations accelerate the molting process.