This study evaluated the influence of the initial weight, feeding period and temperature on weight gain and biological parameters of the non-parasitic phase of partially engorged Rhipicephalus ...sanguineus females that were artificially fed using plastic tips as feeding devices. The device did not alter the oviposition of the females or any other parameters evaluated. Furthermore, it was observed that the temperature of the feeding the group did not affect the weight gain and biology of ticks. This device has great potential for the development of studies on bioagent transmission because it provides higher intake of blood by ixodid ticks.
Cunha N.C., Lemos E.R.S., Rozental T., Teixeira R.C., Cordeiro M.D., Lisbôa R.S., Favacho A.R., Barreira J.D., Rezende J. & Fonseca A.H. Rickettsiae of the Spotted Fever group in dogs, horses and ...ticks: an epidemiological study in an endemic region of the State of Rio de Janeiro, Brazil. Rickettsias do grupo da febre maculosa em cães, equinos e carrapatos: um estudo epidemiológico em região endêmica do estado do Rio de Janeiro, Brasil. Revista Brasileira de Medicina Veterinária, 36(3):294-300, 2014. Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465, Km 7, Seropédica, RJ 23890-000, Brasil. E-mail: adivaldo@ufrrj.br Spotted fever is a disease of which Rickettsia rickettsii is the most pathogenic agent. Its transmission is by tick bites and the infected ticks can act as vectors, reservoirs or amplifiers. The purpose of this paper is to assess the potential of dogs and horses as sentinels for brazilian spotted fever (BSF) emergence and become acquainted with the tick species in a municipal region of Resende, Rio de Janeiro State, Brazil, where five BSF cases in man were registered. Dog and horse blood samples were collected from rural and periurban properties to assess IgG anti-Rickettsia rickettsii, using the indirect immunofluorescence assay (IFA). First, an analysis was conducted to detect association between IFA results and answers obtained from a questionnaire. Afterwards, a multivariate investigation was undertaken that presented significant statistical differences. Ticks were collected directly from dogs and horses for taxonomic identification. Out of the 107 canine serum samples, 30 (28.0%) were reactive, with titers varying from 1:64 to 1:4096, and 77 (72.0%) were not reactive. Of 96 animals in the serum analysis of horses, 9 (9.4%) were reactive, all with titers of 1:64, and 87 (90.6%) were non-reactive. The tick species collected from dogs were Rhipicephalus sanguineus, Amblyomma sculptum, Amblyomma aureolatum, Amblyomma ovale, Rhipicephalus microplus and nymphs of Amblyomma sp., R. sanguineus and R. microplus. Adult ticks gathered from horses were A. cajennense, R. microplus and Dermacentor nitens, in addition to nymphs of Amblyomma sp., R. microplus and D. nitens. The results suggest that: (i) the habit of dogs entering forests and living in rural environments positively influenced the presence of anti-rickettsiae of the spotted fever group serum antibodies, (ii) horses were not good sentinels for this study area and (iii) R. sanguineus as well as A. cajennense ticks were the most prevalent ixodidae fauna of the region.
This study assesses the weight gain of partially engorged Rhipicephalus sanguineus females that were artificially fed via capillary tubes and the influence of capillary tube feeding on the biological ...parameters of the non-parasitic stage of the species. The ticks were sorted into four groups, each containing ten females of a homogeneous weight. The groups were each treated for different feeding times, 2, 6, 12 and 24 hours. The weight gain of the artificially fed females was measured, and the biological parameters of the non-parasitic stage of the tick were observed for each treatment group. The statistical non-parametrical Dunn and Kruskal-Wallis tests were used to compare the results. The mean weights (mg) were 0.2±2.4; 4.3±5.8; 7.4±5.8 and 12.0±11.2 for the 2, 6, 12 and 24 hours feeding groups, respectively. The weight of the fed groups increased as the capillary feeding time increased, and this relationship was highly significant (P<0.05) between the groups fed for 2 and 24 hours. No statistically significant differences (P>0.05) were observed in the parameters of the non-parasitic stage for the artificially fed groups. It can be concluded that artificial feeding via capillary tubes provides an efficient and easy method for the artificial intake of blood by R. sanguineus. Furthermore, it was noted that the ticks fed in vitro were able to establish a new generation. The experimental method shows great promise in studies that aim to investigate biological disease agents.
O objetivo deste trabalho foi avaliar o ganho de peso de fêmeas Rhipicephalus sanguineus parcialmente ingurgitadas alimentadas artificialmente por meio de tubos capilares e verificar a sua influência nos parâmetros biológicos da fase não parasitária. Os carrapatos foram separados em quatro grupos de peso homogêneo compostos por 10 fêmeas cada. Os grupos foram submetidos a diferentes tempos de alimentação: 2, 6, 12 e 24 horas. Para comparação dos resultados, foram utilizados os testes estatísticos não paramétricos Dunn e Kruskal-Wallis. Os pesos médios (mg) adquiridos foram de 0,2±2,4; 4,3±5,8; 7,4±5,8 e 12,0±11,2 nos grupos de 2, 6, 12 e 24 horas, respectivamente. O peso dos grupos alimentados foi maior à medida que o tempo de exposição ao tubo capilar aumentou, observando-se diferença significativa (P<0,05) entre os grupos alimentados por 2 e 24 horas. Não houve diferenças estatísticas significativas (P>0,05) nos parâmetros relativos à fase não parasitária entre os grupos submetidos à alimentação artificial. Concluiu-se que a alimentação artificial por meio de tubos capilares é um método de fácil execução e eficiente para ingestão de sangue por carrapatos R. sanguineus. Além disso, verificou-se que os carrapatos alimentados in vitro foram capazes de estabelecer uma nova geração. Esse método tem potencial para o desenvolvimento de estudos que visem a transmissão de bioagentes.
This study aimed to evaluate, by means of artificial feeding, the interaction between a pathogenic rickettsia and the hard tick R. microplus. We used partially engorged females fed on calves free of ...Rickettsia spp. Group 1 (G1), containing 20 ticks, was fed bovine blood only. Group 2 (G2), containing 20 ticks, was fed blood containing uninfected VERO cells, and group 3 (G3), containing 40 ticks, was fed blood containing VERO cells infected with Rickettsia parkeri. Biological parameters of the non-parasitic phase and a possible bacterial transmission to the tick eggs and to guinea pigs were evaluated. At the end of oviposition, all G3 females were PCR-positive for genes specific for the genus Rickettsia. Although no guinea pigs were infected, the experimental infection of R. microplus by R. parkeri caused a deleterious effect on the oviposition and provided the first report of transovarian transmission of rickettsia in this tick.
This study assesses the weight gain of partially engorged Rhipicephalus sanguineus females that were artificially fed via capillary tubes and the influence of capillary tube feeding on the biological ...parameters of the non-parasitic stage of the species. The ticks were sorted into four groups, each containing ten females of a homogeneous weight. The groups were each treated for different feeding times, 2, 6, 12 and 24 hours. The weight gain of the artificially fed females was measured, and the biological parameters of the non-parasitic stage of the tick were observed for each treatment group. The statistical nonparametrical Dunn and Kruskal-Wallis tests were used to compare the results. The mean weights (mg) were 0.2 ± 2.4; 4.3 ± 5.8; 7.4 ± 5.8 and 12.0 ± 11.2 for the 2, 6, 12 and 24 hours feeding groups, respectively. The weight of the fed groups increased as the capillary feeding time increased, and this relationship was highly significant (P < 0.05) between the groups fed for 2 and 24 hours. No statistically significant differences (P > 0.05) were observed in the parameters of the non-parasitic stage for the artificially fed groups. It can be concluded that artificial feeding via capillary tubes provides an efficient and easy method for the artificial intake of blood by R. sanguineus. Furthermore, it was noted that the ticks fed in vitro were able to establish a new generation. The experimental method shows great promise in studies that aim to investigate biological disease agents. Key words: feeding in vitro, capillary tube, ixodidae. O objetivo deste trabalho foi avaliar o ganho de peso de femeas Rhipicephalus sanguineus parcialmente ingurgitadas alimentadas artificialmente por meio de tubos capilares e verificar a sua influencia nos parametros biologicos da fase nao parasitaria. Os carrapatos foram separados em quatro grupos de peso homogeneo compostos por 10 femeas cada. Os grupos foram submetidos a diferentes tempos de alimentacao: 2, 6, 12 e 24 horas. Para comparacao dos resultados, foram utilizados os testes estatisticos nao parametricos Dunn e Kruskal-Wallis. Os pesos medios (mg) adquiridos foram de 0,2 ± 2,4; 4,3 ± 5,8; 7,4 ± 5,8 e 12,0 ± 11,2 nos grupos de 2, 6, 12 e 24 horas, respectivamente. O peso dos grupos alimentados foi maior a medida que o tempo de exposicao ao tubo capilar aumentou, observando-se diferenca significativa (P < 0,05) entre os grupos alimentados por 2 e 24 horas. Nao houve diferencas estatisticas significativas (P > 0,05) nos parametros relativos a fase nao parasitaria entre os grupos submetidos a alimentacao artificial. Concluiu-se que a alimentacao artificial por meio de tubos capilares e um metodo de facil execucao e eficiente para ingestao de sangue por carrapatos R. sanguineus. Alem disso, verificou-se que os carrapatos alimentados in vitro foram capazes de estabelecer uma nova geracao. Esse metodo tem potencial para o desenvolvimento de estudos que visem a transmissao de bioagentes. Palavras-chave: alimentacao in vitro, tubo capilar, ixodideos.
The establishment of laboratory colonies of ticks is often hampered by their lack of adaptation to alternative hosts. The aim of this study was to artificially feed partially engorged Dermacentor ...(Anocentor) nitens females through plastic tips, and to identify what are the optimal conditions of application of this technique to get as much as possible close to the natural conditions. The technique of artificial feeding through plastic tips allowed the engorgement of D. nitens ticks to a final weight within the normal range for the species.
This study aimed to investigate the frequency of homologous antibodies of IgG class against Borrelia burgdorferi in buffaloes in the state of Pará, Brazil. Blood serum samples from 491 buffaloes were ...analyzed by means of the indirect ELISA test, using crude antigen produced from a cultivar of the North American strain G39/40 of B. burgdorferi. There were 412 positive samples (83.91%), and there was no statistically significant difference in the proportions of positive animals between the 81.69% (232/284) originating from Marajó Island and the 86.96% (180/207) from the continental area of the state of Pará. In all the municipalities studied, the frequency of positive findings of antibodies against B. burgdorferi among the animals ranged from 63.6% to 92.9%. The high numbers of seropositive animals can be explained by the frequent presence of the tick Rhipicephalus (Boophilus)microplus, and by the possible existence of spirochetes of the genus Borrelia infecting buffaloes in the region studied, although specific studies are needed to confirm this relationship. These factors suggest that a cross-reaction exists between the North American strain G39/40 of B. burgdorferi, which is used as an antigenic substrate, and the species of Borrelia spp. that possibly infects buffaloes in the state of Pará.
Silva F.J.M., Silva J.B., Guedes Júnior D.S., Rangel C.P., Teixeira R.C., Fonseca A.H. & Faccini J.L.H. Detection of IgG antibodies to Anaplasma marginale in newborn calves in Baixada Fluminense ...region, RJ. Detec- ção de anticorpos IgG anti-Anaplasma marginale em bezerros recém-nascidos na Baixada Fluminense, RJ. Revista Brasileira de Medicina Veterinária, 37(2):133-137, 2015. Curso de Pós-Graduação em Ciências Veterinárias, Instituto de Veteriná- ria, Universidade Federal Rural do Rio de Janeiro, BR 465 Km 7, Seropédica, RJ 23890-000, Brasil. E-mail: fabiojms@icb.ufrj.br The objectives were to evaluate the prevalence and the seroepidemiological evolution to Anaplasma marginale in 41 calves since birth to first 180 days of life, in a enzootic region in the state of Rio de Janeiro. The analyzed animals belonged to Centro Estadual de Pesquisa em Agricultura Orgânica - Pesagro-Rio, Seropédica-RJ. The study was conducted during the rainy and dry seasons, between 2009 and 2010. A total of 1607 serum samples was collected initially every three days and processed using indirect ELISA test to detect IgG anti-A. marginale antibodies. Percent values for A. marginale seroprevalence as function of age were tested using the χ2 test at 5% significance level. The prevalence of IgG anti-A. marginale antibodies were 39.8% in calves younger than 30 days, 23.3% between 30 and 60 days, 27.3% for 60 and 120 days and 38.2% to 120 and 180 days. Calves with age between 30 and 60, 60 and 120 and 120 and 180 days were respectively 1.90, 1.75 and 1.55 more risk to be seronegative for A. marginale than newborn ones. The results show that calves had low levels of IgG antibodies anti-A marginale in all study, this condition induces them to development of clinical anaplasmosis. Moreover, the property was considered unstable epidemiologically to A. marginale, although located in a endemic stability area.
Leprosy is an infectious disease caused by Mycobacterium leprae and frequently resulting in irreversible deformities and disabilities. Ticks play an important role in infectious disease transmission ...due to their low host specificity, worldwide distribution, and the biological ability to support transovarial transmission of a wide spectrum of pathogens, including viruses, bacteria and protozoa. To investigate a possible role for ticks as vectors of leprosy, we assessed transovarial transmission of M. leprae in artificially-fed adult female Amblyomma sculptum ticks, and infection and growth of M. leprae in tick cell lines. Our results revealed M. leprae RNA and antigens persisting in the midgut and present in the ovaries of adult female A. sculptum at least 2 days after oral infection, and present in their progeny (eggs and larvae), which demonstrates the occurrence of transovarial transmission of this pathogen. Infected tick larvae were able to inoculate viable bacilli during blood-feeding on a rabbit. Moreover, following inoculation with M. leprae, the Ixodes scapularis embryo-derived tick cell line IDE8 supported a detectable increase in the number of bacilli for at least 20 days, presenting a doubling time of approximately 12 days. As far as we know, this is the first in vitro cellular system able to promote growth of M. leprae. Finally, we successfully transformed a clinical M. leprae isolate by inserting the reporter plasmid pCHERRY3; transformed bacteria infected and grew in IDE8 cells over a 2-month period. Taken together, our data not only support the hypothesis that ticks may have the potential to act as a reservoir and/or vector of leprosy, but also suggest the feasibility of technological development of tick cell lines as a tool for large-scale production of M. leprae bacteria, as well as describing for the first time a method for their transformation.
This study aimed to investigate the frequency of homologous antibodies of IgG class against Borrelia burgdorferi in buffaloes in the state of Pará, Brazil. Blood serum samples from 491 buffaloes were ...analyzed by means of the indirect ELISA test, using crude antigen produced from a cultivar of the North American strain G39/40 of B. burgdorferi. There were 412 positive samples (83.91%), and there was no statistically significant difference in the proportions of positive animals between the 81.69% (232/284) originating from Marajó Island and the 86.96% (180/207) from the continental area of the state of Pará. In all the municipalities studied, the frequency of positive findings of antibodies against B. burgdorferi among the animals ranged from 63.6% to 92.9%. The high numbers of seropositive animals can be explained by the frequent presence of the tick Rhipicephalus (Boophilus)microplus, and by the possible existence of spirochetes of the genus Borrelia infecting buffaloes in the region studied, although specific studies are needed to confirm this relationship. These factors suggest that a cross-reaction exists between the North American strain G39/40 of B. burgdorferi, which is used as an antigenic substrate, and the species of Borrelia spp. that possibly infects buffaloes in the state of Pará.Este estudo teve como objetivo investigar a frequência de anticorpos homólogos da classe IgG contra Borrelia burgdorferi em búfalos do estado do Pará. Amostras de soro de 491 búfalos foram analisadas por meio do teste ELISA indireto, utilizando antígeno bruto produzido a partir do cultivo da cepa norte americana G39/40 de B. burgdorferi. Foram encontrados 412 soros positivos (83,91%), não havendo diferença estatística significativa entre os 81,69% (232/284) animais positivos provenientes da Ilha de Marajó e os 86,96% (180/207) da base continental do estado do Pará. Em todos os municípios estudados os animais apresentaram frequência de anticorpos contra B. burgdorferi, com positividade variando de 63,6% a 92,9%. O alto número de soropositivos pode ser explicado pela frequente presença do carrapato Rhipicephalus (Boophilus) microplus e pela possível existência de espiroquetas do gênero Borrelia infectando búfalo na região estudada, embora novos estudos sejam necessários para a confirmação desta relação. Estes fatos sugerem reação cruzada entre a cepa americana G39/40 de B. burgdorferi utilizada como substrato antigênico e a espécie de Borrelia spp. que possivelmente infecta bubalinos no estado do Pará.
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