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ivermectin resistance status and factors associated in rhipicephalus microplus (acari: ixodidae) populations from veracruz, mexico.the objectives of the present study were to (1) determine the status of resistance or susceptibility to ivermectin (ivm) in rhipicephalus microplus tick populations in veracruz, mexico, (2) determine the level of resistance (resistance ratios [rr] and lethal concentrations for 50% [lc(50)] and 99% [lc(99)]) mortality in each r. microplus population, and (3) identify factors associated with resistance. populations of r. microplus were sampled from 53 cattle farms to evaluate their resistance usin ...201222785128
ticks on buffaloes (bubalus bubalis) in the state of rio de janeiro, brazil.some tick species have been described parasitizing buffaloes, but reports from brazil are rare. this study aimed to ascertain the species of ticks that parasitize buffaloes in the state of rio de janeiro. seventeen farm properties were visited between june 2008 and december 2009, and buffaloes were inspected in relation to infestation. the ticks were identified and a semi-structured questionnaire on parasitism and treatment against ticks was filled out through interviews with the owners. the spe ...201223070448
acaricidal action of destruxins produced by a marine-derived beauveria felina on the bovine tick rhipicephalus (boophilus) microplus.the increasing resistance of rhipicephalus (boophilus) microplus tick to commercial insecticides requires alternative methods for the control of this cattle plague. the enthomopathogenic fungus beauveria felina produces destruxins in culture media, cyclic depsipeptides which display an array of biological activities. the present investigation aimed to evaluate the acaricide action of destruxins isolated from b. felina culture media on r. (b.) microplus engorged females. b. felina was grown in mf ...201222955115
[survey on ticks and detection of new bunyavirus in some vect in the endemic areas of fever, thrombocytopenia and leukopenia syndrome (ftls) in henan province].to investigate the distribution, species, seasonal fluctuation of ticks and detect new bunyavirus in some hematophagus in the endemic areas of fever thrombocytopenia and leukopenia syndrome (ftls) in henan province.201222943894
molecular characterization of dsc1 orthologs in invertebrate species.dsc1 and bsc1 are two founding members of a novel family of invertebrate voltage-gated cation channels with close structural and evolutionary relationships to voltage-gated sodium and calcium channels. in this study, we searched the published genome sequences for dsc1 orthologs. dsc1 orthologs were found in all 48 insect species, and in other invertebrate species belonging to phyla mollusca, cnidaria, hemichordata and echinodermata. however, dsc1 orthologs were not found in four arachnid species ...201222321571
nomuraea rileyi as biological control agents of rhipicephalus microplus tick.nomuraea rileyi, a fungus pathogenic to insects, has been widely used for biological control of agricultural pests in brazil. this study investigates the effects of n. rileyi, isolates nr 138, nr 151, and nr 177, to eggs, larvae, and engorged females of rhipicephalus microplus tick. specimens were immersed in 1 ml of conidial suspension for 3 min, whereas the control group was immersed in 0.01% tween 80 water solution. the isolate nr 138 controlled 67.37% of ticks when the highest conidial conce ...201222782472
multi-antigenic vaccine against the cattle tick rhipicephalus (boophilus) microplus: a field evaluation.the tick rhipicephalus (boophilus) microplus is a blood-sucking ectoparasite of cattle that severely impairs livestock production. studies on tick immunological control address mostly single-antigen vaccines. however, from the commercial standpoint, so far no single-antigen vaccine has afforded appropriate protection against all r. microplus populations. in this context, multi-antigen cocktails have emerged as a way to enhance vaccine efficacy. in this work, a multi-antigenic vaccine against r. ...201222981764
comparative efficacy of rhaa86 and rbm86 against hyalomma anatolicum anatolicum and rhipicephalus (boophilus) microplus.hyalomma anatolicum anatolicum and rhipicephalus (boophilus) microplus are the most economically important tick species in india and other tropical and subtropical regions of the world and transmit pathogens causing animal and human diseases. we demonstrated that vaccination of animal by rhaa86 could be used for the control of both h. a. anatolicum and r. (b.) microplus infestations. by comparing the efficacy of rhaa86 and rbm86, it was observed that vaccine based on rhaa86 will be more effectiv ...201222313386
molecular characterization of bm86 gene orthologs from hyalomma excavatum, hyalomma dromedarii and hyalomma marginatum marginatum and comparison with a vaccine candidate from hyalomma scupense.the ixodid ticks from the hyalomma genus are important pests of livestock, having major medical and veterinary significance in northern africa. beside their direct pathogenic effects, these species are vectors of important diseases of livestock and in some instances of zoonoses. anti-tick vaccines developed in australia and cuba based on the concealed antigen bm86 have variable efficacy against h. anatolicum and h. dromedarii. this variation in vaccine efficacy could be explained by the variabil ...201222683299
geographic distribution of the invasive cattle tick rhipicephalus microplus, a country-wide survey in benin.the cattle tick rhipicephalus microplus is currently invading the west african region, and little information is available on the spread of this exotic tick in this region. we set out a country-wide field survey to determine its current distribution in benin. ticks were collected on cattle from 106 farms selected by random sampling covering all regions of the country. rhipicephalus annulatus was found on 70 % of all farms, r. decoloratus on 42 %, r. geigyi on 58 %, and r. microplus on 49 %. ther ...201222689006
reinstatement of rhipicephalus (boophilus) australis (acari: ixodidae) with redescription of the adult and larval stages.rhipicephalus australis fuller, the australian cattle tick, is reinstated and the adults and larvae redescribed from material collected in australia. this long ignored boophilid was previously known as r. microplus canestrini for specimens reported in australia and new caledonia. the adults of r. australis are easily recognized by a combination of characters, such as the ventro-medial spurs in the palpal segments of the male, and the abundant, plumose, pale white setae on the dorsum of the femal ...201222897039
bioengineered surfaces to improve the blood compatibility of biomaterials through direct thrombin inactivation.thrombus formation, due to thrombin generation, is a major problem affecting blood-contacting medical devices. this work aimed to develop a new strategy to improve the hemocompatibility of such devices by the immobilization of a naturally occurring thrombin inhibitor into a nanostructured surface. boophilin, a direct thrombin inhibitor from the cattle tick rhipicephalus microplus, was produced as a recombinant protein in pichia pastoris. boophilin was biotinylated and immobilized on biotin-termi ...201222846590
spectroscopic evaluation of thymol dissolved by different methods and influence on acaricidal activity against larvae of rhipicephalus microplus (acari: ixodidae).the acaricidal activity of three thymol formulations was investigated at five concentrations (1.25, 2.5, 5.0, 7.5, and 10.0 mg/ml) on rhipicephalus microplus larvae, and the behavior of its solubility in these formulations was analyzed. the thymol was dissolved in distilled water plus 1 % dimethylsulfoxide as adjuvant under two heating regimes (water bath in formulation 1 and hot plate in formulation 2) as well as without heating in 50 % ethanol and 50 % water (v/v). the acaricidal activity was ...201222797607
the quest for a universal vaccine against ticks: cross-immunity insights.as blood-sucking parasites, ticks inflict great damage to animals and humans in many parts of the world. the continued use of chemical acaricides is not sustainable due to increasing tick resistance, growing public concern over drug residues in food and in the environment, and the high cost of developing new acaricides. therefore, an alternative control strategy is urgently needed. vaccines against ticks have been shown to be functionally feasible, as highlighted by the success of bm86 vaccines ...201222766309
evaluation of stem aqueous extract and synthesized silver nanoparticles using cissus quadrangularis against hippobosca maculata and rhipicephalus (boophilus) microplus.the present study was to determine the efficacies of anti-parasitic activities of synthesized silver nanoparticles (ag nps) using stem aqueous extract of cissus quadrangularis against the adult of hematophagous fly, hippobosca maculata (diptera: hippoboscidae), and the larvae of cattle tick, rhipicephalus (boophilus) microplus (acari: ixodidae). contact toxicity method was followed to determine the potential of parasitic activity. twelve milliliters of stem aqueous extract of c. quadrangularis w ...201222750410
sequence polymorphism in acetylcholinesterase transcripts and genotyping survey of bmache1 in laboratory and mexican strains of rhipicephalus (boophilus) microplus.abstract acetylcholinesterase cdnas, bmache1, bmache2, and bmache3 of rhipicephalus (boophilus) microplus (canestrini) were sequenced and found to exhibit significant polymorphism. a portion of the predicted amino acid substitutions in bmache1, bmache2, and bmache3 were found predominantly in organophosphate-resistant strains, but most did not correlate with resistant status. multiple transcripts were observed from individual ticks, suggesting possible gene duplication or alternative splicing to ...201222679862
survey of pyrethroid and organophosphate resistance in brazilian field populations of rhipicephalus (boophilus) microplus: detection of c190a mutation in domain ii of the para-type sodium channel gene.the cattle tick rhipicephalus (boophilus) microplus causes expressive damage to livestock in brazil and other countries. its control is becoming more difficult due to the development of resistance in populations. early detection of resistance can help in developing effective control strategies. this study evaluated the susceptibility of r. microplus to cypermethrin and chlorpyriphos and was the first attempt to identify the mechanism of resistance (target site insensitivity) in cattle tick popul ...201222647463
effect of calea serrata less. n-hexane extract on acetylcholinesterase of larvae ticks and brain wistar rats.acetylcholinesterase (ache), an enzyme that hydrolyses acetylcholine (ach) at cholinergic synapses, is a target for pesticides and its inhibition by organophosphates leads to paralysis and death of arthropods. it has been demonstrated that the n-hexane extract of calea serrata had acaricidal activity against larvae of rhipicephalus (boophilus) microplus and rhipicephalus sanguineus. the aim of the present study was to understand the mechanism of the acaricidal action of c. serrata n-hexane extra ...201222608349
a rhipicephalus (boophilus) microplus cathepsin with dual peptidase and antimicrobial activity.the cattle tick, rhipicephalus (boophilus) microplus, is a haematophagous arthropod responsible for considerable losses in the livestock industry. immunological control with vaccines is a promising alternative to replace chemical acaricides. due to their importance in parasite physiology, cysteine endopeptidases are potential targets. in a previous study, native vitellin degrading cysteine endopeptidase (vtdce) was successfully tested as a vaccine antigen for bovines against r. microplus. in thi ...201222584130
cattle tick vaccines: many candidate antigens, but will a commercially viable product emerge?the cattle tick, rhipicephalus microplus, is arguably the world's most economically important external parasite of cattle. sustainable cattle tick control strategies are required to maximise the productivity of cattle in both large production operations and small family farms. commercially available synthetic acaricides are commonly used in control and eradication programs, but indiscriminate practices in their application have resulted in the rapid evolution of resistance among populations in t ...201222549026
biological parameters of cattle ticks fed on rabbits.with the objective of encouraging the use of rabbits as alternative hosts for the cattle tick, four rabbits were infested on the ears and back. from the second day of infestation the developmental stages were observed. e duration of larval engorgement and changes were estimated between six and eight days in the region of the back and between 've and seven days in the pinna. e nymphal engorgement and changes occurred at approximately 10.80 ± 2.65 days in the dorsal and 11.00 ± 2.52 days in the ea ...201222534940
acaricide resistance mechanisms in rhipicephalus (boophilus) microplus.acaricide resistance has become widespread in countries where cattle ticks, rhipicephalus (boophilus) microplus, are a problem. resistance arises through genetic changes in a cattle tick population that causes modifications to the target site, increased metabolism or sequestration of the acaricide, or reduced ability of the acaricide to penetrate through the outer protective layers of the tick's body. we review the molecular and biochemical mechanisms of acaricide resistance that have been shown ...201222534937
a systematic, functional genomics, and reverse vaccinology approach to the identification of vaccine candidates in the cattle tick, rhipicephalus microplus.in the post-genomic era, reverse vaccinology is proving promising in the development of vaccines against bacterial and viral diseases, with limited application in ectoparasite vaccine design. in this study, we present a systematic approach using a combination of functional genomics (dna microarrays) techniques and a pipeline incorporating in silico prediction of subcellular localization and protective antigenicity using vaxijen for the identification of novel anti-tick vaccine candidates. a tota ...201222521592
syringe test (modified larval immersion test): a new bioassay for testing acaricidal activity of plant extracts against rhipicephalus microplus.we report a new bioassay "syringe test" (modified larval immersion test) for in vitro evaluation of acaricidal activity of crude plant extracts. prepared syringes, containing eggs of tick, were incubated until 14 d after hatching of eggs, when the bioassay was performed on the larvae. lethal concentrations for 50% of larvae (lc(50)), lc(90) and lc(99) values were calculated for each tested product. 95% confidence intervals for lc(50) were very narrow, indicating a high degree of repeatability fo ...201222516644
facilitative ecological interactions between invasive species: arundo donax stands as favorable habitat for cattle ticks (acari: ixodidae) along the u.s.-mexico border.the cattle tick, rhipicephalus (boophilus) spp. is a key vector of protozoa that cause bovine babesiosis. largely eradicated from most of the united states, the cattle tick continues to infest south texas, and recent outbreaks in this area may signal a resurgence of cattle tick populations despite current management efforts. an improved understanding of the dynamic ecology of cattle fever ticks along the u.s.-mexico border is required to devise strategies for sustainable eradication efforts. man ...201222493861
tick prevention at a crossroad: new and renewed solutions.ticks have major economic impact through diseases they transmit, direct losses due to their detrimental effect and the efforts invested in prevention measures directed against them. chemical acaricides represent the main line of anti-tick defense in both humans and domestic animals, but increasing concerns regarding development of acaricide resistance, especially in the cattle tick rhipicephalus microplus, and environmental safety issues indicate the need for other, less aggressive but equally e ...201222424918
anti-tick monoclonal antibody applied by artificial capillary feeding in rhipicephalus (boophilus) microplus females.the tick rhipicephalus microplus is an ectoparasite harmful to livestock, a vector of disease agents that affects meat and milk production. however, resistance to acaricides reflects the need for alternative tick control methods, among which vaccines have gained increasing relevance. in this scenario, monoclonal antibodies can be used to identify and characterize antigens that can be used as vaccine immunogens. capillary tube artificial feeding of partially engorged r. microplus females with mon ...201222366320
detection of genetic variability in various isolates of cattle tick, boophilus microplus from tamil nadu, india using pcr-rapd analysis.the genomic dna from ten isolates of the cattle tick, boophilus microplus collected in and around chennai, india, was analyzed by random amplified polymorphic dna (rapd) using pcr. selected five random primers were used for the study of genetic variability among different isolates of b. microplus. a high degree of genetic polymorphism with a different pattern of rapd profiles for each tick isolate was detected with all these random primers. this variability was also confirmed by similarity coeff ...201222349940
perturbation of tyraminergic/octopaminergic function inhibits oviposition in the cattle tick rhipicephalus (boophilus) microplus.the cattle tick rhipicephalus microplus, is one of the most damaging livestock ectoparasites. tropical tick infestation limits the introduction of high-yield bovine varieties because they do not have immunity to the diseases transmitted by these ectoparasites. this tick is usually controlled with chemical acaricides but their indiscriminate use has created resistant populations. the discovery of new molecules that can be used for tick control is urgent. based on the knowledge that octopamine, a ...201222343017
protective effects of passively transferred merozoite-specific antibodies against theileria equi in horses with severe combined immunodeficiency.theileria equi immune plasma was infused into young horses (foals) with severe combined immunodeficiency. although all foals became infected following intravenous challenge with homologous t. equi merozoite stabilate, delayed time to peak parasitemia occurred. protective effects were associated with a predominance of passively transferred merozoite-specific igg3.201222038847
functional genomics studies of rhipicephalus (boophilus) annulatus ticks in response to infection with the cattle protozoan parasite, babesia bigemina.ticks are obligate haematophagous ectoparasites of wild and domestic animals as well as humans, considered to be second worldwide to mosquitoes as vectors of human diseases, but the most important vectors of disease-causing pathogens in domestic and wild animals. babesia spp. are tick-borne pathogens that cause a disease called babesiosis in a wide range of animals and in humans. in particular, babesia bovis and babesia bigemina are transmitted by cattle ticks, rhipicephalus (boophilus) annulatu ...201222265898
evolution, expansion and expression of the kunitz/bpti gene family associated with long-term blood feeding in ixodes scapularis.abstract: background: recent studies of the tick saliva transcriptome have revealed the profound role of salivary proteins in blood feeding. kunitz/bpti proteins are abundant in the salivary glands of ticks and perform multiple functions in blood feeding, such as inhibiting blood coagulation, regulating host blood supply and disrupting host angiogenesis. however, kunitz/bpti proteins in soft and hard ticks have different functions and molecular mechanisms. how these differences emerged and whet ...201222244187
Vaccination with BM86, subolesin and akirin protective antigens for the control of tick infestations in white tailed deer and red deer.Red deer (Cervus elaphus) and white-tailed deer (Odocoileus virginianus) are hosts for different tick species and tick-borne pathogens and play a role in tick dispersal and maintenance in some regions. These factors stress the importance of controlling tick infestations in deer and several methods such as culling and acaricide treatment have been used. Tick vaccines are a cost-effective alternative for tick control that reduced cattle tick infestations and tick-borne pathogens prevalence while r ...201222079077
Control of tick infestations in cattle vaccinated with bacterial membranes containing surface-exposed tick protective antigens.Vaccines containing the Rhipicephalus (Boophilus) microplus BM86 and BM95 antigens protect cattle against tick infestations. Tick subolesin (SUB), elongation factor 1a (EF1a) and ubiquitin (UBQ) are new candidate protective antigens for the control of cattle tick infestations. Previous studies showed that R. microplus BM95 immunogenic peptides fused to the Anaplasma marginale major surface protein (MSP) 1a N-terminal region (BM95-MSP1a) for presentation on the Escherichia coli membrane were prot ...201222085549
in vitro ovicidal and cestocidal effects of toxins from bacillus thuringiensis on the canine and human parasite dipylidium caninum.bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. this bacterium may also be used for biological control of helminth parasites in domestic animals. in this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of b. thuringiensis native strains on the zoonotic cestode parasite of dogs, dipylidium caninum (d. caninum). dose and time response curves were determined by coincubating b. thuringiensi ...201223484087
evolutionary and molecular analysis of the emergent severe fever with thrombocytopenia syndrome virus.in 2009, a novel bunyavirus, called severe fever with thrombocytopenia syndrome virus (sftsv) was identified in the vicinity of huaiyangshan, china. clinical symptoms of this zoonotic virus included severe fever, thrombocytopenia, and leukocytopenia, with a mortality rate of ~10%. by the end of 2011 the disease associated with this pathogen had been reported from eleven chinese provinces and human-to-human transmission suspected. however, current understanding of the evolution and molecular epid ...201223438426
epidemiological perspectives of ticks and tick-borne diseases in south sudan: cross-sectional survey results.a cross-sectional study was conducted between september and october 2010 in five states of south sudan that were selected on the basis of the perceived risk of tick-borne diseases. the purpose was to investigate epidemiological parameters of tick-borne diseases in south sudan and their uses in future control strategies. a total of 805 calves were assessed by clinical, microscopic and serological examination and tick counts. the indirect enzyme-linked immuno-sorbent assay (elisa) was used to dete ...201223327317
molecular detection of acinetobacter species in lice and keds of domestic animals in oromia regional state, ethiopia.this study was conducted to determine the presence of acinetobacter and rickettsia species dna in lice and melophagus ovinus (sheep ked) of animals from oromia regional state in ethiopia. from september through november 2011, a total of 207 cattle, 85 sheep, 47 dogs and 16 cats were examined for ectoparasites. results of morphological identification revealed several species of ectoparasites: linognathus vituli (l. vituli), bovicola bovis (b. bovis) and solenopotes capillatus (s. capillatus) on c ...201223285015
ticks collected from selected mammalian hosts surveyed in the republic of korea during 2008-2009.a tick survey was conducted to determine the relative abundance and distribution of ticks associated with selected mammals in the republic of korea (rok) during 2008-2009. a total of 918 ticks were collected from 76 mammals (6 families, 9 species) captured at 6 provinces and 3 metropolitan cities in rok. haemaphysalis longicornis (54.4%) was the most frequently collected tick, followed by haemaphysalis flava (28.5%), ixodes nipponensis (7.6%), ixodes pomerantzevi (4.8%), ixodes persulcatus (4.6% ...201122072840
spotted fever group rickettsia infecting ticks (acari: ixodidae) in the state of santa catarina, brazil.during 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of santa catarina (sc), brazil, including areas where human cases of brazilian spotted fever have been reported. collected ticks belonging to nine species (amblyomma aureolatum, amblyomma cajennense, amblyomma dubitatum, amblyomma longirostre, amblyomma ovale, amblyomma tigrinum, dermacentor nitens, rhipicephalus microplus and rhipicephalus sanguineus) were tested by polym ...201122241112
zero-inflated poisson regression models for qtl mapping applied to tick-resistance in a gyr × holstein f2 population.now a days, an important and interesting alternative in the control of tick-infestation in cattle is to select resistant animals, and identify the respective quantitative trait loci (qtls) and dna markers, for posterior use in breeding programs. the number of ticks/animal is characterized as a discrete-counting trait, which could potentially follow poisson distribution. however, in the case of an excess of zeros, due to the occurrence of several noninfected animals, zero-inflated poisson and gen ...201122215960
use of beauveria bassiana to control northern fowl mites (ornithonyssus sylviarum) on roosters in an agricultural research facility.treatment of northern fowl mite (ornithonyssus sylviarum) infestation on poultry in research facilities can be challenging. the mite has a rapid reproductive cycle (egg to adult in 5 to 7 d), and chemical treatments can be toxic to birds, personnel, and the environment. in addition, antimite treatment may interfere with experimental research designs. the current study evaluated the efficacy of topical application of an entomopathogenic fungus, beauveria bassiana, in the treatment of a naturally ...201122330786
in vitro and in vivo acaricidal activity of a herbal extract.the anti-tick efficacy of combined aqueous herbal extracts of azadirachta indica leaves, nicotiana tabacum leaves, calotropis procera flowers and trachyspermum ammi seeds was evaluated using adult immersion test, larval packet test and ear bag method. the extract exhibited lethal effects on egg laying (index of egg laying=0.371404±0.00435), hatching (22.35%) and total larval mortality at 50 mg ml(-1) and reduced tick intensity on the infested calves (18 detached out of 35 at 45% (w/w) suspension ...201122305296
a deep insight into the sialotranscriptome of the gulf coast tick, amblyomma maculatum.saliva of blood sucking arthropods contains compounds that antagonize their hosts' hemostasis, which include platelet aggregation, vasoconstriction and blood clotting; saliva of these organisms also has anti-inflammatory and immunomodullatory properties. perhaps because hosts mount an active immune response against these compounds, the diversity of these compounds is large even among related blood sucking species. because of these properties, saliva helps blood feeding as well as help the establ ...201122216098
susceptibility of different populations of ticks to entomopathogenic fungi.this study aimed to evaluate the in vitro effect of the entomopathogenic fungi metarhizium anisopliae sensu lato (s.l.) and beauveria bassiana sensu lato (s.l.) on two distinct populations of rhipicephalus microplus, from two different experimental farms. bioassays were performed with engorged females, eggs and larvae. fungal infection was evaluated based on biological parameters of treated engorged females, percentage of hatch from treated eggs, and percentage of mortality and mean lethal time ...201122212684
acaricidal activity of cymbopogon citratus and azadirachta indica against house dust mites.to examine the acaricidal effects of the essential oil of cymbopogon citratus leaf extract (lemongrass) and ethanolic azadirachta indica leaf extract (neem) against house dust mites dermatophagoides farinae (d. farinae) and dermatophagoides pteronyssinus (d. pteronyssinus).201123569794
expressed sequenced tags profiling of resistant and susceptible gyr x holstein cattle infested with the tick rhipicephalus (boophilus) microplus.tick resistance in cattle is mainly found in zebu (bos indicus) animals, although it is also present in some taurine (b. taurus) breeds. in order to characterize functional genes involved in tick resistance/susceptibility in cattle, two cdna libraries were generated using skin tissues of selected holstein x gyr animals. a total of 2700 high-quality reads from both resistant and susceptible cdna were assembled into 458 sequences (contigs) and 834 singletons, with a mean size of 447.7 nucleo ...201122095475
Expression profiling, gene silencing and transcriptional networking of metzincin metalloproteases in the cattle tick, Rhipicephalus (Boophilus) microplus.Tick proteins functioning in vital physiological processes such as blood meal uptake, digestion and reproduction are potential targets for anti-tick vaccines, since vaccination could inhibit these essential functions and ultimately affect tick survival. In this study we identified metzincin metalloproteases from Rhipicephalus microplus as potential vaccine candidates since they are implicated as essential to blood-cavity formation, bloodmeal digestion and reproduction in ixodid ticks. Eight tran ...201122142943
Perceptions and attitudes among milk producers in Minas Gerais regarding cattle tick biology and control.This study evaluates milk producers' knowledge regarding cattle ticks and practices for controlling them. Ninety-three dairymen in Minas Gerais were interviewed. These producers had no information regarding acaricide efficiency tests. To analyze the information, open responses were categorized through "content analysis", and descriptive analysis consisting of extracting the profile highlighted by the highest frequencies. The association between schooling level and knowledge was tested by means o ...201121961747
First transcriptome of the testis-vas deferens-male accessory gland and proteome of the spermatophore from Dermacentor variabilis (Acari: Ixodidae).Ticks are important vectors of numerous human diseases and animal diseases. Feeding stimulates spermatogenesis, mating and insemination of male factors that trigger female reproduction. The physiology of male reproduction and its regulation of female development are essentially a black box. Several transcriptomes have catalogued expression of tick genes in the salivary glands, synganglion and midgut but no comprehensive investigation has addressed male reproduction and mating. Consequently, a ne ...201121949745
Targeting the tick protective antigen subolesin reduces vector infestations and pathogen infection by Anaplasma marginale and Babesia bigemina.The ultimate goal of vector vaccines is the control of vector infestations while reducing pathogen infection and transmission to protect against the many diseases caused by vector-borne pathogens. Previously (Vaccine 2011;29:2248-2254), we demonstrated that subolesin vaccination and release of tick larvae after subolesin knockdown by RNA interference (RNAi) were effective for the control of cattle tick, Rhipicephalus (Boophilus) microplus infestations in cattle. In this study, we used the fact t ...201121951878
comparative studies on the invasion of cattle ticks (rhipicephalus (boophilus) microplus) and sheep blowflies (lucilia cuprina) by metarhizium anisopliae (sorokin).microscopic investigations over time were carried out to study and compare the pathogenesis of invasion of ticks and blowflies by metarhizium anisopliae. the scanning electron microscope and stereo light microscope were used to observe and record processes on the arthropods' surfaces and the compound light microscope was used to observe and record processes within the body cavities. two distinctly different patterns of invasion were found in ticks and blowflies. fungal conidia germinated on the ...201122178573
Effects of destruxin A on Rhipicephalus (Boophilus) microplus ticks (Acari: Ixodidae).This study evaluated the effects of destruxin A on Rhipicephalus (Boophilus) microplus females, since this toxin is one of the likely causes of high mortality induced by the entomopathogenic fungus Metarhizium anisopliae in arthropods. Ticks were immersed or inoculated with different concentrations of destruxin A. Despite the doses applied, there were no deaths or significant alterations in oviposition between the groups treated with destruxin A and the control groups. No other external effect c ...201122166391
equine piroplasmosis associated with amblyomma cajennense ticks, texas, usa.we report an outbreak of equine piroplasmosis in southern texas, usa, in 2009. infection prevalence reached 100% in some areas (292 infected horses). amblyomma cajennense was the predominant tick and experimentally transmitted theileria equi to an uninfected horse. we suggest that transmission by this tick species played a role in this outbreak.201122000367
vaccines to combat the neglected tropical diseases.the neglected tropical diseases (ntds) represent a group of parasitic and related infectious diseases such as amebiasis, chagas disease, cysticercosis, echinococcosis, hookworm, leishmaniasis, and schistosomiasis. together, these conditions are considered the most common infections in low- and middle-income countries, where they produce a level of global disability and human suffering equivalent to better known conditions such as human immunodeficiency virus/acquired immunodeficiency syndrome an ...201121198676
assessment of bacterial diversity in the cattle tick rhipicephalus (boophilus) microplus through tag-encoded pyrosequencing.ticks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. the cattle tick, rhipicephalus (boophilus) microplus, hinders livestock production in tropical and subtropical parts of the world where it is endemic. tick microbiomes remain largely unexplored. the objective of this study was to explore the r. microplus microbiome by applying the bacterial 16s tag-encoded flx-titanium amplicon pyrosequencing (btefap) technique to characterize its bacterial ...201121211038
the penultimate arginine of the carboxyl terminus determines slow desensitization in a p2x receptor from the cattle tick boophilus microplus.p2x ion channels have been functionally characterized from a range of eukaryotes. although these receptors can be broadly classified into fast and slow desensitizing, the molecular mechanisms underlying current desensitization are not fully understood. here, we describe the characterization of a p2x receptor from the cattle tick boophilus microplus (bmp2x) displaying extremely slow current kinetics, little desensitization during atp application, and marked rundown in current amplitude between se ...201121212138
hemelipoglycoprotein from the ornate sheep tick, dermacentor marginatus: structural and functional characterization.tick carrier proteins are able to bind, transport, and store host-blood heme, and thus they function also as antioxidants. nevertheless, the role of carrier proteins in ticks is not fully understood. some of them are found also in tick males which do not feed on hosts to such an extent such as females (there are differences in male feeding in different tick species) and thus they are not dealing with such an excess of heme; some of the carrier proteins were found in salivary glands where the pro ...201121214898
determination of the susceptibility of rhipicephalus (boophilus) microplus (acari: ixodidae) to ivermectin and fipronil by larval immersion test (lit) in uruguay.rhipicephalus (boophilus) microplus is an important cattle pest in uruguay, and the law regulates its control. it is resistant to organophosphates, synthetic pyrethroids and, as recently discovered, to fipronil. resistance to macrocyclic lactones (mls) and amitraz have not been documented; however, veterinarians and farmers have reported treatment failures. the objective of the present work was to study the susceptibility of cattle tick strains from different uruguayan counties to ivermectin (iv ...201121277092
gender-associated genes in filarial nematodes are important for reproduction and potential intervention targets.a better understanding of reproductive processes in parasitic nematodes may lead to development of new anthelmintics and control strategies for combating disabling and disfiguring neglected tropical diseases such as lymphatic filariasis and onchocerciasis. transcriptomatic analysis has provided important new insights into mechanisms of reproduction and development in other invertebrates. we have performed the first genome-wide analysis of gender-associated (ga) gene expression in a filarial nema ...201121283610
control of rhipicephalus (boophilus) microplus infestations by the combination of subolesin vaccination and tick autocidal control after subolesin gene knockdown in ticks fed on cattle.tick subolesin was shown in immunization trials using the recombinant protein to protect hosts against tick infestations. in this study, we demonstrated that subolesin vaccination and release of ticks after subolesin knockdown by rna interference (rnai) could be used for the control of rhipicephalus (boophilus) microplus tick infestations in cattle and suggested that the combination of these methods could increase the efficacy of cattle tick control under some circumstances. the greatest tick co ...201121288805
haplotypes of the bovine igg2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle.bovines present contrasting, heritable phenotypes of infestations with the cattle tick, rhipicephalus (boophilus) microplus. tick salivary glands produce igg-binding proteins (igbps) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. allotypes that occur in the constant region of igg may differ in their capacity to bind with tick igbps; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. i ...201121301827
rna interference in ticks.ticks are obligate hematophagous ectoparasites of wild and domestic animals and humans, and are considered to be second worldwide to mosquitoes as vectors of human diseases(1) and the most important vectors affecting cattle industry worldwide(2). ticks are classified in the subclass acari, order parasitiformes, suborder ixodida and are distributed worldwide from arctic to tropical regions(3). despite efforts to control tick infestations, these ectoparasites remain a serious problem for human and ...201121304465
resistance to cypermethrin, deltamethrin and chlorpyriphos in populations of rhipicephalus (boophilus) microplus (acari: ixodidae) from small farms of the state of são paulo, brazil.a field survey of resistance was conducted based on the larval packet test technique with synthetic pyrethroids (cypermethrin and deltamethrin) and organophosphates (chlorpyriphos) in rhipicephalus (boophilus) microplus field populations from six different regions of the state of são paulo (brazil). 82.6% of the populations showed resistance to cypermethrin, 86.36% to deltamethrin and 65.25% to chlorpyriphos, with 50% presenting resistance to both sp and op acaricide. according to the questionna ...201121306827
oocysts of hepatozoon canis in rhipicephalus (boophilus) microplus collected from a naturally infected dog.canine hepatozoonosis is a tick-borne disease caused by protozoans of the genus hepatozoon. several tick species have been implicated as potential vectors. therefore, extensive studies are needed to determine the 'natural' endemic cycle of this parasite. this paper presents the first report of the presence of hepatozoon canis oocysts in rhipicephalus (boophilus) microplus collected from an infected dog.201121324597
acaricidal, pediculocidal and larvicidal activity of synthesized zno nanoparticles using wet chemical route against blood feeding parasites.the present study was based on assessments of the anti-parasitic activities to determine the efficacies of synthesized zinc oxide nanoparticles (zno nps) prepared by wet chemical method using zinc nitrate and sodium hydroxide as precursors and soluble starch as stabilizing agent against the larvae of cattle tick rhipicephalus (boophilus) microplus, canestrini (acari: ixodidae); head louse pediculus humanus capitis, de geer (phthiraptera: pediculidae); larvae of malaria vector, anopheles subpictu ...201121340566
a further insight into the sialome of the tropical bont tick, amblyomma variegatum.ticks--vectors of medical and veterinary importance--are themselves also significant pests. tick salivary proteins are the result of adaptation to blood feeding and contain inhibitors of blood clotting, platelet aggregation, and angiogenesis, as well as vasodilators and immunomodulators. a previous analysis of the sialotranscriptome (from the greek sialo, saliva) of amblyomma variegatum is revisited in light of recent advances in tick sialomes and provides a database to perform a proteomic study ...201121362191
structural and biochemical characterization of a recombinant triosephosphate isomerase from rhipicephalus (boophilus) microplus.triosephosphate isomerase (tim) is an enzyme with a role in glycolysis and gluconeogenesis by catalyzing the interconversion between glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. this enzyme has been used as a target in endoparasite drug development. in this work we cloned, expressed, purified and studied kinetic and structural characteristics of tim from tick embryos, rhipicephalus (boophilus) microplus (bmtim). the km and vmax of the recombinant bmtim with glyceraldehyde 3-phospha ...201121396445
acaricidal properties of the essential oil and precocene ii obtained from calea serrata (asteraceae) on the cattle tick rhipicephalus (boophilus) microplus (acari: ixodidae).calea serrata less. (asteraceae), an endemic species of south brazil known as "quebra-tudo", is used in afro-brazilian religious rituals and in folk medicine for treating liver disorders. phytochemical studies of the n-hexane extract of this plant demonstrated the presence of precocene ii, a benzopyran derivative known for its insecticidal activity. the aim of this work was to isolate this benzopyran and determine the chemical composition of the essential oil of c. serrata and further to evaluat ...201121402447
acaricidal activity of palicourea marcgravii, a species from the amazon forest, on cattle tick rhipicephalus (boophilus) microplus.leaves of palicourea marcgravii were extracted successively with hexane, ethyl acetate and ethanol in order to evaluate their acaricidal activity on larvae and adult stages of the cattle tick rhipicephalus (boophilus) microplus. the ethyl acetate extract showed the highest bioactivity of the tested extracts, which contained 0.12% monofluoroacetic acid. on engorged female, the ethyl acetate extract showed a lethal concentration 50% - lc(50)=30.08 mg ml(-1), inhibitory concentration 50% - ic(50)=5 ...201121411227
colonization of grande comore island by a lineage of rhipicephalus appendiculatus ticks.union of the comoros suffered a severe east coast fever epidemic in 2004. rhipicephalus appendiculatus was probably involved in pathogen transmission as this competent tick species, although previously absent from comoros, was sampled on 4 animals on one geographical site during the epidemic. we carried out an entomological survey on all three islands of union of the comoros to establish cattle tick species distribution with a special emphasis on r. appendiculatus. we investigated r. appendicula ...201121414194
an important role of a pyrethroid-sensing residue f1519 in the action of the n-alkylamide insecticide btg 502 on the cockroach sodium channel.deltamethrin, a pyrethroid insecticide, and btg 502, an alkylamide insecticide, target voltage-gated sodium channels. deltamethrin binds to a unique receptor site and causes prolonged opening of sodium channels by inhibiting deactivation and inactivation. previous (22)na(+) influx and receptor binding assays using mouse brain synaptoneurosomes showed that btg 502 antagonized the binding and action of batrachotoxin (btx), a site 2 sodium channel neurotoxin. however, the effect of btg 502 has not ...201121426938
phenotype changes inherited by crossing pyrethroid susceptible and resistant genotypes from the cattle tick riphicephalus (boophilus) microplus.dialelic crosses and backcrosses of pyrethroid resistant (rr) and susceptible (ss) rhipicephalus (boophilus) microplus tick strains were carried out and the substitution (phe-ile) within the sodium channel gene was monitored in order to analyze the effects of the genotype on the pyrethroid resistance phenotype as measured by the larval packet test (lpt). parental strains: susceptible (ss) and resistant (rr); dialelic crosses: rs (?rr × ?ss), and sr (?ss × ?rr); and backcrosses: rs × ss, rs × rr, ...201121431928
selective control of rhipicephalus (boophilus) microplus in fipronil-treated cattle raised on natural pastures in lages, state of santa catarina, brazil.an examination of a selective control of rhipicephalus (boophilus) microplus and consequent cost reduction was carried out in two areas of native pasture in the municipality of lages, state of santa catarina, southern brazil, from may 2007 to april 2009. forty cattle were divided into two groups of 20 animals each (conventional and selective control groups). at 14-day intervals female ticks larger than 4.5 mm found on the right flank of cattle bodies were counted, and these results multiplied by ...201121439225
in vitro activity of artemisia annua l (asteraceae) extracts against rhipicephalus (boophilus) microplus.the activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling rhipicephalus (boophilus) microplus. the aim of the present study was to investigate the in vitro action of artemisia annua extracts on this tick. the concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. four extracts produced from the concentrated crude extract (cce ...201121439229
retraction. detection and identification of ehrlichia species in rhipicephalus (boophilus) microplus ticks in cattle from xiamen, china. 201121443413
bacillus sp. cdb3 isolated from cattle dip-sites possesses two ars gene clusters.contamination of soil and water by arsenic is a global problem. in australia, the dipping of cattle in arsenic-containing solution to control cattle ticks in last centenary has left many sites heavily contaminated with arsenic and other toxicants. we had previously isolated five soil bacterial strains (cdb1-5) highly resistant to arsenic. to understand the resistance mechanism, molecular studies have been carried out. two chromosome-encoded arsenic resistance (ars) gene clusters have been cloned ...201121476346
efficacy and blood sera analysis of a long-acting formulation of moxidectin against rhipicephalus (boophilus) microplus (acari: ixodidae) on treated cattle.the therapeutic and persistent efficacy of a single subcutaneous injection of a long-acting formulation of moxidectin at a concentration of 1 mg/kg body weight was determined against rhipicephalus (boophilus) microplus (canestrini), along with the concentration-time blood sera profile in treated cattle. the therapeutic efficacy against ticks of all parasitic stages on cattle at the time of treatment was >99.9%, and the mean tick number, index of fecundity, engorgement weight, and egg mass weight ...201121485367
efficacy of spinosad against acaricide-resistant and -susceptible rhipicephalus (boophilus) microplus and acaricide-susceptible amblyomma americanum and dermacentor variabilis.various acaricide-resistant strains of rhipicephalus (boophilus) microplus, representative of the major resistance mechanisms found in mexico and brazil, were exposed to spinosad using the food and agriculture organization of the united nations larval packet test and adult immersion test (ait). larvae of all strains tested were found to be susceptible to spinosad. conversely, spinosad did not show toxic activity toward engorged females used in the ait. in vitro tests against larvae, nymphs, and ...201121485374
functional characterization of two defensin isoforms of the hard tick ixodes ricinus.abstract:201121504572
temporal characterisation of the organ-specific rhipicephalusmicroplus transcriptional response to anaplasma marginale infection.arthropods transmit important infectious diseases of humans and animals. importantly, replication and the development of pathogen infectivity are tightly linked to vector feeding on the mammalian host; thus analysis of the transcriptomes of both vector and pathogen during feeding is fundamental to understanding transmission. using anaplasma marginale infection of rhipicephalusmicroplus as the experimental model, we tested three hypotheses exploring the temporal and organ-specific nature of the t ...201121514300
copper nanoparticles synthesized by polyol process used to control hematophagous parasites.the present study was based on assessments of the anti-parasitic activities of the hematophagous (blood feeding) larvae of malaria vector, anopheles subpictus grassi, filariasis vector, culex quinquefasciatus, say (diptera: culicidae), and the larvae of cattle tick rhipicephalus (boophilus) microplus, canestrini (acari: ixodidae). the metallic copper nanoparticles (cu nps) synthesized by polyol process from copper acetate as precursor and tween 80 were used as both the medium and the stabilizing ...201121526405
detection and differentiation of borrelia burgdorferi sensu lato in ticks collected from sheep and cattle in china.abstract:201121529349
boophilus microplus cathepsin l-like (bmcl1) cysteine protease: specificity study using a peptide phage display library.the tick rhipicephalus (boophilus) microplus is one of the most important bovine ectoparasites, a disease vector responsible for losses in meat and milk productions. a cysteine protease similar to cathepsin l, named bmcl1, was previously identified in r. microplus gut, suggesting a role of the enzyme in meal digestion. in this work, bmcl1 was successfully expressed in pichia pastoris system, yielding 54.8mg/l of culture and its activity was analyzed by synthetic substrates and against a r. micro ...201121536386
in vitro acaricidal activity of neem (azadirachta indica) seed extracts with known azadirachtin concentrations against rhipicephalus microplus.the effect of four extracts from neem seeds (azadirachta indica) containing 2000, 5000, 9000 and 10,000ppm of azadirachtin a (aza), quantified by high-performance liquid chromatography (hplc) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick rhipicephalus microplus. the results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameter ...201121536387
a calcium bioluminescence assay for functional analysis of mosquito (<em>aedes aegypti</em>) and tick (<em>rhipicephalus microplus</em>) g protein-coupled receptors.arthropod hormone receptors are potential targets for novel pesticides as they regulate many essential physiological and behavioral processes. the majority of them belong to the superfamily of g protein-coupled receptors (gpcrs). we have focused on characterizing arthropod kinin receptors from the tick and mosquito. arthropod kinins are multifunctional neuropeptides with myotropic, diuretic, and neurotransmitter function. here, a method for systematic analyses of structure-activity relationships ...201121540818
evaluation of the efficacy of acaricides used to control the cattle tick, rhipicephalus microplus, in dairy herds raised in the brazilian southwestern amazon.the adult immersion test (ait) was used to evaluate the efficacy of acaricide molecules used for control of rhipicephalus microplus on 106 populations collected in five municipalities in the state of rondônia in the brazilian south occidental amazon region. the analysis of the data showed that the acaricide formulations had different efficacies on the tick populations surveyed. the synthetic pyrethroids (sps) acaricides were the least effective (48.35-76.84%), followed by sp + organophosphate (o ...201121547224
evolution of acaricide resistance: phenotypic and genotypic changes in field populations of rhipicephalus (boophilus) microplus in response to pyrethroid selection pressure.there have been few, if any, studies of arthropod field populations quantifying the kinetics of evolution of phenotypic and genotypic resistance to chemicals in response to the presence or absence of selection pressure. a prospective intervention study was undertaken over 2years in mexico to measure changes in resistance phenotype and genotype in the presence or absence of pyrethroid selection pressure on field populations of rhipicephalus (boophilus) microplus ticks on 11 farms with varying deg ...201121570981
effect of metarhizium anisopliae fungus on off-host rhipicephalus (boophilus) microplus from tick-infested pasture under cattle grazing in brazil.this work aimed to assess the effect of the fungus metarhizium anisopliae on off-host rhipicephalus (boophilus) microplus from tick-infested brachiaria decumbens pasture undergoing cattle grazing. for this purpose a naturally tick-infested brachiaria decumbens pasture of 60m×100m with twelve grazing holstein friesian-nelore (bos indicus) cross breed bovines was sprayed 12 times, 21 days apart with an aqueous conidial suspension of the e9 isolate of m. anisopliae fungus. control pasture was treat ...201121571437
enhancing the stress tolerance and virulence of an entomopathogen by metabolic engineering dhn-melanin biosynthesis genes.entomopathogenic fungi have been used for biocontrol of insect pests for many decades. however, the efficacy of such fungi in field trials is often inconsistent, mainly due to environmental stresses, such as ultraviolet radiation, temperature extremes, and desiccation. to circumvent these hurdles, metabolic engineering of dhn-melanin biosynthetic genes (polyketide synthase, scytalone dehydratase, and 1,3,8-trihydroxynaphthalene reductase) cloned from alternaria alternata were transformed into th ...201121571888
effect of water flooding on the oviposition capacity of engorged adult females and hatchability of eggs of dog ticks: rhipicephalus sanguineus and haemaphysalis leachi leachi.effects of water flooding on the oviposition capacity of engorged adult females and hatchability of eggs of rhipicephalus sanguineus and haemaphysalis leachi leachi under laboratory conditions were investigated. the durations of time of water flooding were 1, 2, 4, 6, 12, 24, 48, 72, 96, and 120 hours. engorged females of r. sanguineus and h. leachi leachi did not oviposit after being flooded for more than 48 and 6 hours, respectively. the preoviposition periods of both species were longer than ...201121584237
a snapshot of the ixodes scapularis degradome.parasitic encoded proteases are essential to regulating interactions between parasites and their hosts and thus they represent attractive anti-parasitic druggable and/or vaccine target. we have utilized annotations of ixodes scapularis proteases in gene bank and version 9.3 merops database to compile an index of at least 233 putatively active and 150 putatively inactive protease enzymes that are encoded by the i. scapularis genome. the 233 putatively active protease homologs hereafter referred t ...201121596113
diazinon resistant status in rhipicephalus (boophilus) microplus collected from different agro-climatic regions of india.the resistance status of rhipicephalus (boophilus) microplus to "diazinon" was evaluated in 20 locations situated at various agro-climatic regions of india. adult immersion test (ait) was optimized using laboratory reared acaricide susceptible ivri-i strain of r. (b.) microplus and minimum effective concentration of diazinon was determined as 635.2ppm. the discriminating dose (dd) was worked out as 1270.4ppm and was tested on female ticks collected from organized and unorganized farms located at ...201121600695
tick-borne bacteria in free-living jaguars (panthera onca) in pantanal, brazil.abstract tick-borne bacteria were investigated in 10 free-living jaguars and their ticks in the pantanal biome, brazil. jaguar sera were tested by indirect fluorescent antibody assays using rickettsia rickettsii, rickettsia parkeri, rickettsia amblyommii, rickettsia rhipicephali, rickettsia felis, rickettsia bellii, ehrlichia canis, and coxiella burnetii as crude antigens. all 10 jaguar sera reacted (titer ≥64) to at least one rickettsia species; 4 and 3 sera reacted with e. canis and c. burneti ...201121612532
rhipicephalus (boophilus) microplus embryo proteins as target for tick vaccine.rhipicephalus (boophilus) microplus is one of the most widely distributed tick in the world. the control of the parasite is based mainly on the use of chemical acaricides, which are produced from a limited set of molecules. these drugs induce selection of acaricide-resistant ticks, and are an important source of environmental pollution. an approach based on anti-tick vaccines may circumvent these obstacles. characterization of the physiological function of tick molecules may be useful to develop ...201121620488
perceptions about the biology of rhipicephalus (boophilus) microplus among milk producers in divinópolis, minas gerais.one hundred semi-systematized interviews were applied with the aim of surveying the perceptions of milk producers in the municipality of divinópolis, minas gerais regarding the biology of the tick rhipicephalus (boophilus) microplus. content analysis was conducted on each of the variables surveyed and their descriptions, highlighting the higher frequencies in order to construct profiles of perceptions about each of the matters surveyed. in addition, each of the producers was categorized regardin ...201122166382
larvicidal activity of isolated compound 5-(2,4-dimethylbenzyl) pyrrolidin-2-one from marine streptomyces vitsvk5 sp. against rhipicephalus (boophilus) microplus, anopheles stephensi, and culex tritaeniorhynchus.the aim of the present study was to assess the larvicidal property of marine actinobacterial compound 5-(2,4-dimethylbenzyl) pyrrolidin-2-one (dmbpo) extracted and isolated from streptomyces vitsvk5 sp. tested against the larvae of rhipicephalus (boophilus) microplus canestrini (acari: ixodidae), anopheles stephensi liston, and culex tritaeniorhynchus giles (diptera: culicidae). the isolate bacteria was taxonomically characterized, identified, and designated as streptomyces vitsvk5 sp. the crude ...201122009268
the prevalence of pyrethroid resistance phenotype and genotype in rhipicephalus (boophilus) microplus in yucatan, mexico.a field survey was conducted to evaluate susceptibility of rhipicephalus (boophilus) microplus to cypermethrin on 49 farms in three areas of yucatan, mexico. the modified larval packet test was used to evaluate larval mortality at different cypermethrin concentrations. dose-mortality regressions, lethal concentrations (lc(50)-lc(99)), confidence intervals and slope were estimated by probit analysis. phenotype was defined as susceptible, tolerant or resistant when the resistance factor (rf) deriv ...201121978740
resistance of cattle of various genetic groups to the tick rhipicephalus microplus and the relationship with coat traits.this study evaluated the resistance of cattle of different genetic groups to the tick rhipicephalus microplus and the relationship with traits of the animals' hair and coat. cows of the senepol×nelore (sn), angus×nelore (an) and nelore (nx) genetic groups were submitted to four consecutive artificial infestations, at 14-day intervals, each one with approximately 20,000 tick larvae placed on the animals' lumbar region. from the 19th to 23rd day of each infestation five counts of the number of tic ...201122115946
relationships between tick counts and coat characteristics in nguni and bonsmara cattle reared on semiarid rangelands in south africa.indigenous nguni cattle are adapted to the semiarid rangeland and appear to be resistant to ticks; however, the mechanism for tick resistance is yet to be established. to understand tick resistance in cattle, relationships among skin thickness, hair length, coat score, and tick counts were estimated in nguni (n=12) and bonsmara (n=12) heifers on semiarid rangelands of south africa. the tick species observed to infest the heifers were rhipicephalus (boophilus) decoloratus (frequency: 76%), rhipic ...201121890073
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