Sequence characteristics of Rhipicephalus microplus Enolase gene and prediction of structure and antigenic epitopes of its encoding protein / 中国血吸虫病防治杂志

Objective To analyze the sequence characteristics of Rhipicephalus microplus Enolase gene, and to predict the secondary and tertiary structure and antigenic epitopes of the Enolase protein. Methods Sixty-two engorged female R. microplus were sampled from a yellow cattle breeding farm in Zhijiang County, Huaihua City, Hunan Province in June 25, 2022. Genomic DNA was isolated from R. microplus, and the Enolase gene was amplified using PCR assay, followed by cloning, sequencing and expression of the amplification product. The sequence characteristics of the Enolase gene were analyzed using the software Clustal X, and the gene sequence was translated into amino acid sequences. The secondary and tertiary structures of the Enolase protein were deduced using the software PRABI, and the physicochemical properties of the Enolase protein were analyzed using the software PRABI. In addition, the B- and T-cell epitopes of the Enolase protein were predicted using the software ABCpred Prediction, Scratch, IEDB and NetCTL. Results The R. microplus Enolase gene sequence was 1 323 bp in size, and the contents of A, T, G and C bases were 24.5%, 22.5%, 27.0% and 26.0%,with 47.0% of A + T content and 53.0% of G + C content. The R. microplus Enolase gene encoded 434 amino acids, and the Enolase protein had a molecular weight of 47.12 kDa. The secondary structure of the Enolase protein contained 186 α-helixes (42.86%), 32 β-turns (7.37%), 144 random coils (33.18%) and 72 extended strands (16.59%). The Enolase protein was most probably present in cytoplasm (76.7%), followed by in mitochondrion (39.1%) and nucleus (21.7%), and the Enolase protein had no signal peptide or transmembrane domain. In addition, the Enolase protein had 14 B-cell dominant epitopes and 8 T-cell dominant epitopes. Conclusions The R. microplus Enolase gene sequence exhibits a GC preference, and its encoding Enolase protein is an acidic and hydrophilic protein, with α-helixes and random coils as its primary structure, and presenting B- and T-cell dominant epitopes, which is a potential target for development of vaccines against R. microplus.

Effects of essential oils on native and recombinant acetylcholinesterases of Rhipicephalus microplus / Efeito de óleos essenciais sobre acetilcolinesterases nativa e recombinante de Rhipicephalus microplus

Abstract This study reports the action of essential oils (EO) from five plants on the activity of native and recombinant acetylcholinesterases (AChE) from Rhipicephalus microplus. Enzyme activity of native susceptible AChE extract (S.AChE), native resistant AChE extract (R.AChE), and recombinant enzyme (rBmAChE1) was determined. An acetylcholinesterase inhibition test was used to verify the effect of the EO on enzyme activity. EO from Eucalyptus globulus, Citrus aurantifolia, Citrus aurantium var.dulcis inhibited the activity of S.AChE and R.AChE. Oils from the two Citrus species inhibited S.AChE and R.AChE in a similar way while showing greater inhibition on R.AChE. The oil from E. globulus inhibited native AChE, but no difference was observed between the S.AChE and R.AChE; however, 71% inhibition for the rBmAChE1 was recorded. Mentha piperita oil also inhibited S.AChE and R.AChE, but there was significant inhibition at the highest concentration tested. Cymbopogon winterianus oil did not inhibit AChE. Further studies are warranted with the oils from the two Citrus species that inhibited R.AChE because of the problem with R. microplus resistant to organophosphates, which target AChE. C. winterianus oil can be used against R. microplus populations that are resistant to organophosphates because its acaricidal properties act by mechanism(s) other than AChE inhibition.

Resumo Este estudo relata a ação de óleos essenciais de cinco plantas na atividade de acetilcolinesterases (AChE) nativas e recombinantes de Rhipicephalus microplus. A atividade enzimática do extrato de acetilcolinesterase nativa suscetível (S.AChE) e resistente (R.AChE) e da enzima recombinante (rBmAChE1) foi determinada. Um teste de inibição da AChE foi utilizado, para verificar o efeito dos óleos essenciais sobre a atividade enzimática. Óleos essenciais de Eucalyptus globulus, Citrus aurantifolia, Citrus aurantium var. dulcis inibiram a atividade de S.AChE e R.AChE. Os óleos das duas espécies de Citrus inibiram S.AChE e R.AChE de maneira semelhante, mas mostraram maior inibição sobre R.AChE. O óleo de E. globulus inibiu a AChE nativa, mas sem diferença entre a S.AChE e a R.AChE; no entanto, 71% de inibição para rBmAChE1 foi observada. O óleo de Mentha piperita também inibiu S.AChE e R.AChE, mas houve inibição significativa apenas nas concentrações mais altas testadas. O óleo de Cymbopogon winterianus não inibiu a AChE. Estudos adicionais são necessários com os óleos das duas espécies de Citrus que inibiram a R.AchE, devido ao problema de R. microplus resistente aos organofosforados ter como alvo AChE. O óleo de C. winterianus pode ser usado contra populações de R. microplus, que são resistentes a organofosforados, porque suas propriedades acaricidas agem por mecanismos diferentes.

Effects of climate changes on the distribution of Rhipicephalus microplus in China / 中国血吸虫病防治杂志

Objective To identify the environmental factors affecting the geographical distribution of Rhipicephalus microplus in China, and to examine the impact of climate changes on the distribution of R. microplus in China. Methods The national and international publications pertaining to the geographical distribution of R. microplus in China were retrieved, and the geographical location was extracted. The suitable habitats of R. microplus and the dominant environmental factors affecting the distribution of suitable habitats of R. microplus were predicted in China based on the geographical data and environmental variables using the ArcGIS 10.7 software and the maximum entropy model. Results Among the main climatic factors affecting the geographical distribution of R. microplus in China, the factors contributing more than 10% to the suitable habitats of R. microplus mainly include the annual mean precipitation (38.2%), the average temperature of the coldest quarter (28.4%) and the precipitation of the driest month (14.2%). The current suitable habitats of R. microplus were mainly found in southern China, and the high-, medium- and low-suitable areas accounted for 8.6%, 13.1% and 10.5% of the total land area of China, respectively. The suitable habitats of R. microplus were predicted to increase by 399 800 km2 in China using the maximum entropy model under the RCP 4.5 emissions scenario in 2070, and the emerging suitable habitats were mainly distributed in Gansu Province, Ningxia Hui Autonomous Region, Qinghai Province, Hebei Province, Shaanxi Province, Liaoning Province, Inner Mongolia Autonomous Region, Shandong Province, Sichuan Province and Tibeten Autonomous Region. In addition, the suitable habitats of R. microplus were predicted to show an overall expansion towards northward from present to 2070. Conclusions Climate changes affect the distribution of suitable habitats of R. microplus in China, and annual mean precipitation may be a key factor affecting the distribution of suitable habitats of R. microplus.

Acaricidal potential of volatile oils from Croton species on Rhipicephalus microplus

ABSTRACT The objective of this study was to evaluate the acaricidal activity of the volatile oils of three species of Croton, Euphorbiaceae, against the cattle tick Rhipicephalus microplus. The volatile oils were obtained by hydrodistillation, analyzed by GC-MS and GC-FID and their acaricidal activity was evaluated by the larval packet test and adult immersion test. The volatile oils from Croton conduplicatus Kunth, Croton pulegiodorus Baill., and two different collections of Croton grewioides Baill. (CG1 and CG2) showed eucalyptol (24.09%), p-cymene (23.13%) and methyl chavicol (83.59% and 95.38%) as the major compounds, respectively. All the volatile oils tested in this study showed efficacy against larvae and engorged females of Rhipicephalus microplus. Therefore, Croton pulegiodorus volatile oil is promising for a potential acaricidal formulation because of the best activity against both stages of the cattle tick.

Chemical composition and acaricidal activity of Ocotea notata (Lauraceae), an endemic species from Brazil, against the cattle tick Rhipicephalus microplus / Composición química y actividad acaricida de Ocotea notata (Lauraceae), una especie endémica de Brasil, contra la garrapata del ganado Rhipicephalus microplus

Rhipicephalus microplus, is one parasites that cause severe productivity losses in the cattle industry of Brazil and shows increasing resistance to conventional pesticides. This research aims to study the chemical composition, and acaricidal activity of the essential oil from Ocotea notata leaves, a brazilian endemic species, against R. microplus. The effect on R. microplus engorged adult females was evaluated using the immersion test. The oil reduced the survival by 90% after incubation for 15 days and there was 100% reduction for posture inhibition and reproductive capacity. These results suggest that the O. notata essential oil has activity on the R. microplus.

Rhipicephalus microplus, es un parásito que causa graves pérdidas de productividad en la industria ganadera de Brasil y muestra una creciente resistencia a los pesticidas convencionales. Esta investigación tiene como objetivo estudiar la composición química y la actividad acaricida del aceite esencial de las hojas de Ocotea notata, una especie endémica brasileña, contra R. microplus. El efecto sobre las hembras adultas engordadas de R. microplus se evaluó mediante la prueba de inmersión. El aceite redujo la supervivencia en 90% después de la incubación durante 15 días y hubo una reducción del 100% para la inhibición de la postura y la capacidad reproductiva. Estos resultados sugieren que el aceite esencial de O. notata tiene actividad contra R. microplus.

In vivo effect of diflubenzuron, administered via mineral salt supplementation, against Haematobia irritans and Rhipicephalus microplus parasitizing cattle / Efeito in vivo do diflubenzuron, administrado via sal mineral, contra Haematobia irritans e Rhipicephalus microplus parasitando bovinos

Abstract This study involved two field trials with the aim of evaluating the efficacy of diflubenzuron, via mineral supplementation, against Haematobia irritans parasitizing cattle. Concomitantly with the main trial, a stall test was conducted to ascertain the effects of a different formulation with the same active ingredient against Rhipicephalus microplus, along with the action of diflubenzuron on the reproductive parameters of R. microplusfemales that had naturally detached from cattle. Against H. irritans, it was observed that the efficacy indexes fordiflubenzuron were low (≤ 31.3% or 44.6%) or null (0.0%) throughout the study. The anti- R. microplus efficacy of diflubenzuron, at weekly intervals, ranged from 0.0 to 13.7% over the entire experimental period. Null efficacy (0.0%) was registered for diflubenzuron in relation to the reproductive parameters of R. microplusfemales that had naturally detached from cattle. The different diflubenzuron formulations, administered via mineral salt supplementation, did not show satisfactory efficacy indexes against H. irritans and R. microplus parasitizing cattle, within the experimental design of the present study. In addition, this agent did not present any deleterious effects on the reproductive parameters of R. microplus females.

Resumo O objetivo deste estudo foi avaliar a eficácia do diflubenzuron, administrado via suplementação mineral, contra Haematobia irritans parasitando bovinos, em dois testes à campo. Concomitantemente, foi realizado testes em estábulo para determinar os efeitos de uma formulação diferente, com o mesmo princípio ativo, contra Rhipicephalus microplus , bem como a ação do diflubenzuron nos parâmetros reprodutivos de fêmeas de R. microplus recolhidas após desprendimento natural do hospedeiro bovino. Contra H. irritans, foi observado que foram baixos (≤ 31,3% ou 44,6%) ou nulos (0,0%) os índices de eficácia do diflubenzuron. A eficácia anti-R. microplus do diflubenzuron, observada em intervalos semanais, variaram de 0,0% a 13,7% durante todo o período experimental. Com relação aos parâmetros reprodutivos das fêmeas de R. microplus recolhidas, foi observada eficácia nula (0,0%) para o diflubenzuron. Conclui-se que as diferentes formulações administradas via sal mineral no atual estudo, contra H. irritans e R. microplus parasitando bovinos, não apresentaram eficácia satisfatória. Este agente também não mostrou efeito deletério sobre os parâmetros reprodutivos de fêmeas de R. microplus.

Analysis of Bm86 conserved epitopes: is a global vaccine against Cattle Tick Rhipicephalus microplus possible? / Análise de epítopos conservados da Bm86: é possível uma vacina global contra Carrapato-do-Boi Rhipicephalus microplus?

Abstract The cattle tick Rhipicephalus microplus causes significant economic losses in agribusiness. Control of this tick is achieved mainly through the application of chemical acaricides, often resulting in contamination of animal food products and of the environment. Another major concern associated with acaricide use is the increasing reports of resistance of this tick vector against the active ingredients of many commercial products. An alternative control method is vaccination. However, the commercially available vaccine based on a protein homologous to Bm86 exhibits variations in efficacy relative to the different geographical locations. This study aimed to identify antigenic determinants of the sequences of proteins homologous to Bm86. Phylogenetic analyses were performed to determine the extent of divergence between different populations of R. microplus to identify the sequence that could be used as a universal vaccine against the multiple geographically distinct populations of R. microplus and related tick species. Considering the extensive sequence and functional polymorphism observed among strains of R. microplus from different geographical regions, we can conclude that it may be possible to achieve effective vaccination against these cattle ticks using a single universal Bm86-based antigen.

Resumo O carrapato Rhipicephalus microplus é responsável por perdas significativas no agronegócio. O controle deste carrapato é feito principalmente por meio da aplicação de acaricidas químicos, geralmente resultando na contaminação de produtos de origem animal e do meio ambiente. Outra preocupação importante associada ao uso de acaricidas é o crescente aumento de relatos sobre a resistência deste carrapato a princípios ativos de vários produtos comerciais. Uma alternativa de controle é por meio de vacinação. Porém, a vacina comercializada contendo proteína homóloga à Bm86, apresenta variações de eficácia em relação às diferentes localizações geográficas. Este estudo buscou identificar determinantes antigênicos das sequencias de proteínas homólogas a Bm86. As análises filogenéticas foram feitas para determinar a extensão da divergência entre diferentes populações de R. microplus com o objetivo de identificar a sequência que poderia ser usada como vacina universal contra as múltiplas populações geograficamente distintas de R. microplus e espécies de carrapatos relacionados. Considerando-se a extensa sequência e o polimorfismo observados entre linhagens de R. microplus de diferentes regiões geográficas, podemos concluir que pode ser possível obter uma vacinação efetiva contra esses carrapatos bovinos utilizando um único antígeno universal baseado em Bm86.

Atividade acaricida de diferentes solventes sobre fêmeas ingurgitadas e larvas de Rhipicephalus microplus / Acaricidal activity of different solvents on engorged females and larvae of Rhipicephalus microplus

Os carrapatos causam perdas econômicas à indústria pecuária no Brasil. Dessa forma, o uso de fitoterápicos como acaricidas mostrou eficácia no controle desses parasitas. Neste estudo, foi avaliada a eficácia in vitro dos seguintes fármacos: dimetil sulfóxido (DMSO), etanol, metanol, propilenoglicol e monolaurato de sorbitan polietilenoglicol em diluições de 100%, 20%, 10%, 5%, 1% e 0,5%. O efeito tóxico destes solventes em fêmeas e larvas ingurgitadas de Rhipicephalus microplus foi analisado. O teste de biocarrapaticidograma, foi utilizado para definir a eficiência reprodutiva das teleóginas de R. microplus e a eficiência dos produtos testados. Para análise da susceptibilidade das larvas foi utilizado o teste por imersão de larvas em seringa modificado. O uso de propilenoglicol e DMSO em fêmeas ingurgitadas e o uso de DMSO, etanol, metanol e propilenoglicol em larvas, todos à concentração de 0,5%, apresentaram uma menor taxa de mortalidade, podendo ter seu uso indicado em baixas concentrações como solventes de acaricidas utilizados no controle do R. microplus.(AU)

Cattle ticks cause economic losses to the cattle industry in Brazil. The use of phytotherapics as acaricides has shown efficacy of the control of these parasites. In the present study, the in vitro efficacy of the following drugs was evaluated: dimethyl sulfoxide (DMSO), ethanol, methanol, propylene glycol and polyethylene glycol sorbitan monolaurate at dilutions 100%, 20%, 10%, 5%, 1% e 0.5%. The toxic effect of these solvents on engorged female and larvae of Rhipicephalus microplus was analyzed. The immersion test was used to define the reproductive efficiency of engorged R. microplus females and efficiency of the drugs. The immersion test larvae modified syringe was used to analyze of the susceptibility of tick larvae. Propylene glycol and DMSO was used on engorged females and DMSO, ethanol, methanol and propylene glycol, all at concentration of 0.5%, were use on larvae the, showed the lowest mortality rate; this indicate that its use at low concentrations as solvent acaricide in the control of R. microplus could be recommended.(AU)

Perfil do produtor de leite da região de Joanópolis/SP: como ele lida com o controle do carrapato Rhipicephalus microplus e de outras doenças de importância veterinária / Profile of dairy farmers of the Joanópolis/SP region, Brazil: how they deal with Rhipicephalus microplus control and other diseases of veterinary interest

Este estudo verificou o perfil do produtor de leite do município de Joanópolis, SP, situado a 115 km de São Paulo, e como esse produtor lida com o controle do carrapato e outras doenças importantes na pecuária leiteira. Quarenta produtores de leite foram entrevistados. Verificou-se que grande parte deles se enquadra em agricultura familiar: pequenas propriedades com mão-de-obra familiar. Verificou-se que 72,5% possuem outra fonte de renda além do leite; 75% produzem menos que 100 litros de leite por dia, e a maioria não é tecnificada (ordenha manual: 72,5 %; não faz escrituração zootécnica: 55%; não aduba pastos: 80%; não utiliza inseminação artificial: 87,5%). O controle do carrapato é feito sem critérios técnicos; a aplicação do carrapaticida é feita no mesmo local da ordenha; 90% não usam equipamentos de proteção individual para aplicar o carrapaticida. O gado prevalente é o mestiço Girolando (87,5%), que, por ser mais resistente ao carrapato, deve contribuir para que 57,5% dos entrevistados estejam satisfeitos com o controle do carrapato. Verificou-se que poucos produtores (apenas 12,5%) possuem assistência técnica constante. Isso pode ser a explicação para o baixo uso de tecnologias e nas falhas observadas no diagnóstico das doenças e no controle do carrapato.(AU)

This study made a detailed description of the milk producer of the municipality of Joanópolis/SP, situated 115 km from the largest city of Brazil, São Paulo, and how they deal with tick control and other important diseases for dairy farming. Forty milk producers were interviewed. It was found that most of them fit into family farms: small farms with family labor; 72.5% have another source of income in addition to the milk; 75% produce less than 100 liters of milk per day; and most of them are not technified (72.5% do manual milking; 55% do not keep zootechnical records; 80% do not fertilize the pastures; 87.5 % do not use artificial insemination). Tick control is made without technical criteria. A hundred percent of the interviewed applied the acaricide in the same place of milking; 90% do not use protective equipment to apply the acaricide. The prevalent cattle breed is the crossbred Girolando (87.5%), a more tick resistant breed. This may contribute to 57.5% that are satisfied with tick control. It was found that few producers (only 12.5%) have constant technical assistance. This may be the explanation for the low use of technologies and the failures observed in the diagnosis of diseases and the use of tick control.(AU)

Anti-inflammatory and antinociceptive activities of Rhipicephalus microplus saliva

Objective: To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host. Methods: For saliva collection, engorged ticks were obtained from a controlled bovine infestation and collected by natural fall. The ticks were fixed and injected pilocarpine 0.2％for induction of salivation. Saliva was collected, lyophilized and stored at - 80 ℃. Cytotoxic activity was assessed by the hemolysis method (25, 50, 100, 200 and 300 μg/mL) and MTT cell viability assay (2.5, 5, 10, 20 and 40 μg/mL) for 24, 48 and 72 h. Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of 10, 15 and 20 mg/kg; antinociceptive activity was assessed using the acetic acid-inducedwrithing test, and formalin-induced paw-licking in mice at dose of 15 mg/kg. Results: Saliva did not cause erythrocytes hemolysis at any concentration tested, as well as did not decrease cell viability in the MTT assay. Saliva inhibited neutrophil migration by 87％ and 73％ at doses of 15 and 20 mg/kg, respectively. In the nociceptive tests, saliva presented analgesic activity of 69.96％ in the abdominal writhing test, and of 84.41％ in the formalin test. Conclusions: The study proves that Rhipicephalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities. The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and,in future, to develop novel anti-inflammatory and analgesic drugs.

Anti-inflammatory and antinociceptive activities of Rhipicephalus microplus saliva

Objective: To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host. Methods: For saliva collection, engorged ticks were obtained from a controlled bovine infestation and collected by natural fall. The ticks were fixed and injected pilocarpine 0.2% for induction of salivation. Saliva was collected, lyophilized and stored at - 80 °C. Cytotoxic activity was assessed by the hemolysis method (25, 50, 100, 200 and 300 μ g/mL) and MTT cell viability assay (2.5, 5, 10, 20 and 40 μ g/mL) for 24, 48 and 72 h. Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of 10, 15 and 20 mg/kg; antinociceptive activity was assessed using the acetic acid-induced writhing test, and formalin-induced paw-licking in mice at dose of 15 mg/kg. Results: Saliva did not cause erythrocytes hemolysis at any concentration tested, as well as did not decrease cell viability in the MTT assay. Saliva inhibited neutrophil migration by 87% and 73% at doses of 15 and 20 mg/kg, respectively. In the nociceptive tests, saliva presented analgesic activity of 69.96% in the abdominal writhing test, and of 84.41% in the formalin test. Conclusions: The study proves that Rhipicephalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities. The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and, in future, to develop novel anti-inflammatory and analgesic drugs.

Identification and prevalence of ticks (Acari, Ixodidae) in bovines in five municipalities of the Popayán plateau (Colombia) / Identificación y prevalencia de garrapatas (Acari, Ixodidae) en bovinos en cinco municipios de la meseta de Popayán (Colombia) / Identificação e prevalência de carrapatos (Acari, Ixodidae) em bovinos em cinco municípios no planalto de Popayán (Colombia)

Abstract Background: Ticks and tick-borne diseases are one of the major problems of public and animal health worldwide. Tick infestation causes economic losses in cattle farms of the Popayán plateau (Cauca, Colombia) due to costs associated with preventive management, decreased production of milk and meat, as well as transmission of diseases such as babesiosis and anaplasmosis. Objective: To determine the type and degrees of tick infestation in cattle of the Popayán plateau and its correlation with erythrogram and blood parasites frequency. Methods: One-thousand four-hundred forty cattle were evaluated in 144 farms distributed in Popayán, Cajibio, Timbio, Morales, and Piendamó. In each farm ticks were collected, quantified, and identified from 10 bovines of 1 year of age or older regardless of sex or breed. Additionally, a blood sample was taken from five of the animals to evaluate the erythrogram and determine the presence of blood parasites. Results: Tick prevalence was 79.5%; of these, 99.6% were Rhipicephalus microplus and 0.4% were Dermacentor nitens. Most cattle (58%) presented medium and high degrees of tick infestations (11 to 50, and more than 50 ticks, respectively) with a weak relationship between the degree of tick infestation and red blood cell counts, and no relationship between the degree of tick infestation and the presence of blood parasites. Conclusion: Cattle herds in Popayán plateau have a medium to high degree of tick infestation with R. microplus.

Resumen Antecedentes: Las garrapatas y enfermedades transmitidas por estas son uno de los grandes problemas de salud pública y veterinaria en el mundo. En la meseta de Popayán (Cauca, Colombia) la infestación por garrapatas causa pérdidas económicas en las explotaciones ganaderas debido a mayores costos por manejo preventivo, disminución en la producción de leche, carne y pieles, y transmisión de enfermedades como babesiosis y anaplasmosis. Objetivo: Determinar el tipo de garrapatas y grado de infestación en bovinos de la meseta de Popayán y correlacionarlo con el eritrograma y presencia de hemoparásitos. Métodos: Se evaluaron 1.440 bovinos en 144 fincas de los municipios de Popayán, Cajibio, Timbio, Morales y Piendamó. En cada finca se colectaron, cuantificaron, e identificaron las garrapatas de 10 bovinos mayores de 1 año, independientemente de sexo o raza, y a cinco de ellos se les tomó muestra de sangre para realizar eritrograma y determinar presencia de hemoparásitos. Resultados: La prevalencia de garrapatas fue 79,5%; de ellas, 99,6% eran Rhipicephalus microplus y 0,4% Dermancentor nitens. La mayoría de los bovinos (58%) presentaron infestación media y alta (11 a 50, y más de 50 garrapatas, respectivamente). Se encontró una baja relación entre grado de infestación y nivel de glóbulos rojos, y no se encontró relación entre grado de infestación y presencia de hemoparásitos. Conclusión: Las ganaderías de la meseta de Popayán presentan un grado medio-alto de infestación por garrapatas, principalmente por R. microplus.

Resumo Antecedentes: Os carrapatos e as doenças transmitidas por eles são um dos principais problemas de saúde pública e animal em todo o mundo. No planalto de Popayán, departamento de Cauca (Colômbia), a infestação por carrapato é uma importante causa de perdas econômicas nas explorações pecuárias devido aos custos de manejo preventivo, diminuição da produção de leite, carne e peles, além da transmissão de doenças como babesiose e anaplasmose. Objetivo: Determinar o tipo de carrapato e o grau de infestação em bovinos no planalto de Popayán e correlacioná-los com os achados no eritrograma e a presença de hemoparasitas. Métodos: Foram avaliados 1.440 animais em 144 fazendas distribuídas nos municípios de Popayán, Cajibio, Timbio, Morales e Piendamó. Em cada propriedade foram coletados, quantificados e identificados carrapatos de 10 bovinos com mais de 1 ano de idade independentemente do sexo ou raça; de cinco deles foram colatadas amostras de sangue para realização de eritrograma e determinação da presença de hemoparasitas. Resultados: A prevalência de carrapatos foi de 79,5%; 99,6% dos carrapatos identificados eram da espécie Rhipicephalus microplus e 0,4% Dermancentor nitens. A maioria dos animais (58%) apresentou média e alta infestação (11 a 50 e mais do 50, respectivamente). Foi encontrada uma baixa relação entre o grau de infestação por carrapatos e número de células vermelhas no sangue, e não foi encontrada nenhuma relação entre grau de infestação por carrapatos e a presença de hemoparasitas. Conclusaõ: Os bovinos no planalto de Popayán apresentam um grau de infestação por carrapatos médio-alto, principalmente por R. microplus.

Resistencia in vitro de la garrapata Rhipicephalus microplus a organofosforados, piretroides y amitraz en el Departamento de Boyacá, Colombia / In vitro Resistance of Rhipicephalus microplus ticks to Organophosphates, Pyrethroids and Amitraz in Boyacá Department, Colombia

El presente estudio evaluó la resistencia in vitro de la garrapata Rhipicephalus microplus a organofosforados (OF), piretroides sintéticos (PS) y amitraz (AM). Las garrapatas adultas fueron recolectadas en Boyacá, Colombia y sometidas a la prueba de inmersión para evaluar la eficacia de los fármacos, el efecto sobre la ovoposición y el porcentaje de eclosión larvaria. Se utilizó un diseño experimental completamente al azar con cinco grupos y tres repeticiones por tratamiento, con 10 garrapatas por repetición. Los resultados demostraron tasas de mortalidad a las moléculas evaluadas, encontrando 43, 56, 60 y 96% de mortalidad para el grupo control, PS, AM y OF, respectivamente, al día 21 del experimento. La inhibición de la ovoposición fue de 13,4% para el grupo control, 44,6% para AM, 45,5% para PS y 96% para OF. El porcentaje de eclosión de huevos fue de 88% para el grupo control, 16% para AM, 14% para PS y 4% para OF. El presente estudio in vitro representa el primer diagnóstico en el departamento de Boyacá, Colombia.

The present investigation evaluated the in vitro resistance of the Rhipicephalus microplus tick, to organophosphates (OP), synthetic pyretroids (SP), and amitraz. Adult ticks were collected in the Department of Boyacá, Colombia, and subjected to the immersion test, to assess the efficacy of drugs, their effect on oviposition, and the percentage of larvae eclosion. A completely randomized experimental design was used, with 5 groups and 3 replicates per group, with 10 ticks per replicate. The results showed that the mortality rates in terms of percentage (%) of the assessed molecules were: 43 for the control group; 56 for SP; 60 for AM, and 96 for OP, respectively, at day 21 of the study. The inhibition of oviposition was: 13.4% for the control group; 44.6% for AM; 45.5% for SP; and 96% for OP. The present in vitro study represents the first diagnostic of resistance in the Department of Boyacá, Colombia.

Cattle tick differentiates between the odors of Holstein Friesian and Nelore cattle / Carrapato de bovinos diferencia o odor de bovinos da raça Holandesa e Nelore

Although Rhipicephalus microplusmainly parasitizes bovines, different breeds can have variable parasite burdens, with indian breeds being less susceptible to tick infestation than european breeds. These ticks use pasture questing to seek out their hosts in the open spaces of their grassland habitats. Using an olfactometer bioassay, where the larva could express questing, the authors aimed to answer whether R. microplusexhibit different behaviors depending on the bovine breed. Sixteen larvae were individually exposed to the odors of five holstein friesian cattle, five nelore cattle, hexane (negative control) and 2-nitrophenol (positive control). The highest questing responses were observed to 2-nitrophenol and holstein odors. The lowest response was observed to the solvent and was statistically similar to nelore odors. It is possible to conclude that R. microplusexpress different questing behaviors depending on the odor of the breed perceived. This behavior can help R. microplusto avoid parasitizing nelore bovines and is biologically advantageous for the tick because it is known that ticks that feed on this host have impaired development.

Embora Rhipicephalus microplusparasite principalmente bovinos, diferentes raças podem ter cargas parasitárias variáveis, sendo os bovinos indianos menos suscetíveis a esse carrapato que os bovinos europeus. Este carrapato usa um comportamento de procura conhecido como questing para encontrar seu hospedeiro nas pastagens. Utilizando um teste em olfatômetro, onde a larva podia expressar o questing, objetivou-se responder se a larva podia expressar diferentes comportamentos dependendo da raça de bovino envolvida. Dezesseis larvas foram expostas para os odores de cinco bovinos holandeses, cinco nelores, hexano (controle negativo) e 2-nitrofenol (controle positivo). As mais altas respostas foram observadas para o 2-nitrofenol e odor de holandês. A mais baixa resposta foi observada para o solvente e foi estatisticamente similar ao odor de nelore. É possível concluir que R. microplusexpressa de forma diferente o comportamento de questing dependendo do odor da raça de bovinos percebido. Esse comportamento pode ajudar R. microplusa evitar parasitar bovinos nelore, o que é biologicamente vantajoso para o carrapato, uma vez que se sabe que carrapatos alimentados neste hospedeiro têm seu desenvolvimento comprometido.

Evaluación de la eficacia de la CEPA MAF1309® de Metarhizium anisopliae en el control biológico de garrapatas adultas de Rhipicephalus microplus en Tunja, Colombia / Evaluation of efficacy of MaF1309® strain of Metarhizium anisopliae in biological control of adult ticks Rhipicephalus microplus in Tunja, Colombia

La garrapata del ganado Rhipicephalus microplus constituye el ectoparásito de mayor importancia en las ganaderías de regiones tropicales y subtropicales, al producir pérdidas directas por reducción de la producción de carne, leche y deterioro de las pieles así como a la transmisión de agentes patógenos para el ganado bovino tales como Babesia bovis, Babesia bigemina y Anaplasma marginale. El tratamiento químico ha sido efectivo para el control de las garrapatas; sin embargo,  su uso excesivo ha propiciado la selección de individuos resistentes y por tal motivo, se hace necesario el desarrollo de nuevas alternativas de control, tales como el uso de hongos entomopatógenos. El objetivo del presente estudio fue evaluar la eficacia in vitro de M. anisopliae para el control de la fase adulta de R. microplus, en Tunja, Colombia. Se usó la prueba de inmersión de adultas para evaluar la eficacia de la cepa MaF1309® de M. anisopliae a las siguientes concentraciones: 1x10(4), 1x10(6) y 1x10(8) conidias/mL. Se observó que en las garrapatas tratadas a una concentración de 1x10(8) conidias/mL se alcanzó el 100% de mortalidad a los 14 d postratamiento (PT), mientras que las concentraciones 1x10(6) y 1x10(4) conidias/mL alcanzaron el 100% de mortalidad a los días 16 y 20 PT, respectivamente. La mortalidad fue directamente proporcional a la concentración empleada del hongo, siendo las garrapatas tratadas con concentraciones mayores aquellas que alcanzaron una mortalidad en menor tiempo. Estos resultados in vitro son considerados el inicio de información de tipo local proyectados al diseño de programas de control para el departamento de Boyacá.

The livestock tick Rhipicephalus microplus is a high importance ectoparasite in cattle raised at tropical and sub-tropical regions producing direct losses since reduce meat and milk production and cause leather injury besides transmission of pathogenic agents such as Babesia bovis, Babesia bigemina y Anaplasma marginale. The chemical treatment has been effective to control tick  however the excessive use has selected resistant individuals; for that reason is important to develop new alternatives such as entomopathogen fungi to keep controlled those individuals. The objective of this research was to evaluate in vitro efficacy of M. anisopliae to control adult stage of R. microplus in Tunja, Colombia. The immersion test was used to evaluate efficacy of MaF1309® strain of M. anisopliae at concentrations of 1x10(4), 1x10(6) y 1x10(8) conidia/mL. The group of ticks treated with 1x10(8) conidia had 100% of mortality 14 post-treatment days (PT), otherwise 1x10(6) y 1x10(4) conidia/mL concentrations have 100% of mortality at 16 and 20 PT days, respectively. Mortality was directly proportional to fungus concentration used, the ticks treated with high concentrations reach high mortality in less time. Those in vitro results start in local information projected to design control programs for the department of Boyacá.

Characterisation of divergent flavivirus NS3 and NS5 protein sequences detected in Rhipicephalus microplus ticks from Brazil

Transcripts similar to those that encode the nonstructural (NS) proteins NS3 and NS5 from flaviviruses were found in a salivary gland (SG) complementary DNA (cDNA) library from the cattle tick Rhipicephalus microplus. Tick extracts were cultured with cells to enable the isolation of viruses capable of replicating in cultured invertebrate and vertebrate cells. Deep sequencing of the viral RNA isolated from culture supernatants provided the complete coding sequences for the NS3 and NS5 proteins and their molecular characterisation confirmed similarity with the NS3 and NS5 sequences from other flaviviruses. Despite this similarity, phylogenetic analyses revealed that this potentially novel virus may be a highly divergent member of the genus Flavivirus. Interestingly, we detected the divergent NS3 and NS5 sequences in ticks collected from several dairy farms widely distributed throughout three regions of Brazil. This is the first report of flavivirus-like transcripts in R. microplus ticks. This novel virus is a potential arbovirus because it replicated in arthropod and mammalian cells; furthermore, it was detected in a cDNA library from tick SGs and therefore may be present in tick saliva. It is important to determine whether and by what means this potential virus is transmissible and to monitor the virus as a potential emerging tick-borne zoonotic pathogen.

Epidemiology of ixodid ticks in cattle population of various agro-climatic zones of Punjab, India

OBJECTIVE@#To determine the epidemiology of ixodid ticks in bovines of different agro-climatic zones of Punjab state, India.@*METHODS@#A total of 4 459 cattle of all age groups and sex were examined from eighteen districts of five major agro-climatic zones of Punjab state, India.@*RESULTS@#The overall prevalence of ixodid ticks, Rhipicephalus microplus (R. microplus), Hyalomma anatolicum anatolicum (H. a. anatolicum) and mixed infestation were 58.06%, 50.16%, 11.34% and 3.45%, respectively. Among the various agro-climatic zones highest prevalence rate of R. microplus and H. a. anatolicum were recorded in submountain undulating region (79.36%) and western region (20.40%), respectively indicating that R. microplus prefers a hot and humid environment whereas, arid and semi arid conditions suit better for H. a. anatolicum. The overall prevalence of ixodid ticks was highest in monsoon season (83.74%), followed by summer (69.01%) and least in winters (31.64%) and a significant variation (P1year age group (55.02%) and the difference was statistically significant (P<0.01). Also a significantly higher (P<0.01) infestation rates of ixodid ticks was observed in males.@*CONCLUSIONS@#The findings of the current study would provide a basis for evolving effective control strategy for the management of ticks in bovines of the region.

Primary embryonic cells of Rhipicephalus microplus and Amblyomma cajennense ticks as a substrate for the development of Borrelia burgdorferi (strain G39/40) / Células primárias embrionárias do carrapato Rhipicephalus microplus e Amblyomma cajennense como substrato para desenvolvimento de Borrelia burgdorferi (Cepa G39/40)

Borrelia burgdorferi, the agent of Lyme borreliosis, is a spirochetes transmitted by ticks to humans and animals. Its cultivation in vitro in tick cells allows studies of its biology and provides methodology for future research in Brazil, and for the isolation of Borrelia spp. We examined in vitro the characteristics of embryonic cells of Rhipicephalus microplus and Amblyomma cajennense in cell culture and investigated the suitability of embryonic cells as a substrate for cultivation of B. burgdorferi. Subcultures were prepared from primary cultures of embrionary cells of R. microplus and A. cajennense maintained in Leibovitz's (L-15) complete medium at 28 ºC and 31 ºC, respectively. When a monolayer had formed, the L-15 was replaced with Barbour-Stoener-Kelly medium for experiments to infect cell cultures with B. burgdorferi. After 72 hours of cultivation, the spirochetes were counted using an inverted phase contrast microscope and dark-field illumination (400×). Survival, multiplication and the adherence of B. burgdorferi for embryonic cells of R. microplus and A. cajennense were observed. B. burgdorferi cultured with embryonic cells of R. microplus grew on average to a density (final count) of 2.4 × 10(7) spirochetes/mL, whereas in cell-free culture, an average of 2.5 × 10(7) spirochetes/mL were counted. When cultivated with A. cajennense cells, the final count of spirochetes was on average 1.7 × 10(7) spirochetes/mL, while spirochetes cultured under cell-free conditions replicated on average of 2.2 × 10(7) spirochetes/mL. Similar results were observed in the final count of Spirochetes cultivated in cells of R. microplus and A. cajennense, when compared with cell-free control. These results demonstrated that cells of R. microplus and A. cajennense have the potential to be used as growth substrate for B. burgdorferi in the study of its interaction with host cells.

Borrelia burgodorferi, o agente da borreliose de Lyme, é uma espiroqueta transmitida por carrapatos aos seres humanos e animais. Seu cultivo in vitro em células de carrapato permite estudos de sua biologia e propicia metodologia para futuras pesquisas no Brasil, para o isolamento de Borrelia spp. Nós examinamos in vitro as características de células embrionárias de Rhipicephalus microplus e Amblyomma cajennense, e a viabilidade de utilização dessas células embrionárias como um substrato para cultivo de B.burgdorferi. Subculturas foram preparadas a partir de culturas primárias de células embrionárias de R. microplus e A. cajennense mantidas em meio Leibovitz's (L-15) completo, a 28 ºC e 31 ºC, respectivamente. Com a formação da monocamada, o L-15 foi substituído pelo meio Barbour-Stoener-Kelly, para o experimento de infecção com B. burgdorferi nas culturas de células. Após 72 horas de cultivo, realizou-se a contagem das espiroquetas, as quais foram avaliadas sob microscópio invertido de contraste de fase e campo escuro (400×). Verificou-se a sobrevivência, a multiplicação e a aderência de B. burgdorferi em células embrionárias de R. microplus e A. cajennense. No estudo da cultura de B. burgdorferi com células embrionárias de R. microplus, observou-se, na contagem final, média de 2,4 × 10(7) espiroquetas/mL; no cultivo livre de células, verificou-se média de 2,5 × 10(7) espiroquetas/mL. No cultivo de A. cajennense, a contagem final de espiroquetas foi, em média, 1,7 × 10(7) espiroquetas/mL, enquanto que, para as cultivadas livres de células, se verificou média de 2,2 × 10(7) espiroquetas/mL. Resultado semelhante foi observado na contagem final de espiroquetas cultivadas em células de R. microplus e A. cajennense, quando comparado com o controle livre de células. Estes resultados demonstraram que células de R. microplus e A. cajennense têm o potencial para serem utilizadas como substrato para o crescimento de B. burgdorferi no estudo da interação com as células do hospedeiro.

Efeito do extrato aquoso do algodão de seda (Calotropis procera Aiton) sobre a eficiência reprodutiva do carrapato bovino / Effect of aqueous extract of silk cotton (Calotropis procera Ait. R.Br.) on the reproductive performance of Rhipicephalus microplus

O carrapato Rhipicephalus microplus é um dos principais parasitos dos rebanhos bovinos. Diferentes grupos de carrapaticidas sintéticos têm sido empregados para o controle desse ácaro, contudo, o uso constante desses produtos tem selecionado populações resistentes. Na tentativa de minimizar esses impactos tem-se buscado avaliar fitoterápicos para o controle desse parasito. Assim, objetivou-se analisar a eficácia in vitro do extrato aquoso do algodão de seda em diferentes concentrações no controle da postura e eclodibilidade dos ovos do R. microplus. Foram avaliados os efeitos das concentrações 1, 5, 10, 25, 50, 75 e 100% do extrato aquoso obtido juntamente com controles com água destilada ou com cipermetrina, 12,5 mg L-1, associada a organofosforado, 150 mg L-1, sobre a eficiência reprodutiva do carrapato. Foi realizado o biocarrapaticidograma sendo que a eficácia acaricida das concentrações 5, 25 e 100% foram superiores àquela observada para o produto comercial utilizado, que correspondeu a 93,98%, indicando a importância de futuras pesquisas para avaliar o potencial toxigênico e a eficácia in vivo dessa planta para o controle do R. microplus .

The tick Rhipicephalus microplus is one of the main parasites of bovine herds. Different groups of synthetic acaricides have been used to control this mite; however, the constant use of these products has selected resistant populations. In an attempt to minimize these impacts, researchers have tried to evaluate herbal remedies to control this parasite. Therefore, the aim of this study was to analyze the in vitro efficacy of aqueous extract of silk cotton at different concentrations to control the hatchability of R. microplus eggs. The effects of the concentrations 1, 5, 10, 25, 50, 75 and 100% aqueous extract together with controls with distilled water or with cypermethrin, 12.5 mg L-1, associated with organophosphate, 150 mg L-1, were assessed on the reproductive efficiency of the tick. Immersion test was performed and the acaricide efficacy of the 5, 25 and 100% concentrations were higher than that obtained for the commercial product, which corresponded to 93.98%, indicating the importance of further research to assess the toxigenic potential and the in vivo efficacy of this plant to control R. microplus .

Identification of Haemaphysalis longicomis and Rhipicephalus microplus / 中华流行病学杂志

Objective To establish a method combined morphology and molecular marker for identifying Haemaphysalis longicomis and Rhipicephalus microplus. Methods Ticks were collected from domestic animals and wild environment in epidemic area of Hubei and Henan provinces where cases of fever with thrombocytopenia syndrome were prevalent. We classified the ticks by morphology characteristics before 12S rDNA of ticks were amplified by PCR and subsequently sequenced. Phylogenetic tree was constructed by PAUP4.0. Results The ticks belonged to Haemaphysalis longicomis and Rhipicephalus microplus through observation and analysed by the morphological characteristics of the ticks. 12S rDNA was cloned and sequenced while data confirmed the morphological identification of the results. Conclusion The method based on morphology that combined with molecular marker seemed a good method for the identificaton of ticks.