| effect of aqueous extracts of baccharis trimera on development and hatching of rhipicephalus microplus (acaridae) eggs. | this study evaluated the effects of aqueous extracts of baccharis trimera (less.) dc (asteraceae), colloquially known as carqueja, on egg production, and hatching rate of larvae of rhipicephalus microplus. plant samples were collected in montes claros, north of minas gerais, brazil. adult female ticks were distributed into 24 homogeneous groups of 10. the in vitro test was performed by immersing each group in 10 ml solutions of aqueous extracts at 50, 100, 150, or 200mg of fresh leaves ml(-1). t ... | 2013 | 23347758 |
| in vitro activities of plant extracts from the brazilian cerrado and pantanal against rhipicephalus (boophilus) microplus (acari: ixodidae). | a total of 73 ethanol extracts from different anatomical parts of 44 plant species belonging to 24 families, native to the mid-western region of brazil, were assessed in vitro for their effect on the reproductive cycle of engorged females of the cattle tick rhipicephalus (boophilus) microplus, using the adult immersion test. all extracts were evaluated at the concentration of 0.2 % and, among the extracts tested, the one obtained from the fruits of guarea kunthiana (meliaceae) proved to be highl ... | 2013 | 23344640 |
| acaricidal activity of lippia gracilis essential oil and its major constituents on the tick rhipicephalus (boophilus) microplus. | the present study aimed to evaluate the activity of lippia gracilis schauer essential oil obtained from different l. gracilis genotypes and their major components, carvacrol and thymol against rhipicephalus (boophilus) microplus (cattle tick) larvae and engorged females. the larval test was performed parallel to the adult immersion test for engorged females for four l. gracilis genotypes. similar tests were further performed for their major compounds carvacrol and thymol. carvacrol (lc50 of 0.22 ... | 2013 | 23337330 |
| the conserved role of the akt/gsk3 axis in cell survival and glycogen metabolism in rhipicephalus (boophilus) microplus embryo tick cell line bme26. | tick embryogenesis is a metabolically intensive process developed under tightly controlled conditions and whose components are poorly understood. | 2013 | 23274741 |
| activity of essential oil of lippia triplinervis gardner (verbenaceae) on rhipicephalus microplus (acari: ixodidae). | the objective of this work was to characterize and investigate the acaricidal activity of the essential oil of the aerial parts of lippia triplinervis at different concentrations on unengorged larvae and engorged females of rhipicephalus microplus. the essential oil yielded 2.21 % (w/w to dry matter) and was composed mainly of carvacrol (31.9 %), thymol (30.6 %), and p-cymene (12.3 %). two tests were performed to assess the acaricidal activity: the modified larval packet test, with concentration ... | 2013 | 23224609 |
| evolution of the tissue factor pathway inhibitor-like kunitz domain-containing protein family in rhipicephalus microplus. | one of the principle mechanisms utilised by ticks to obtain a blood meal is the subversion of the host's haemostatic response. this is achieved through the secretion of saliva containing anti-haemostatic proteins into the feeding lesion. lineage-specific expansion of predicted secretory protein families have been observed in all previously studied ticks and occurred in response to adaptation to a blood-feeding environment. of these, the predominant families are common between both hard and soft ... | 2013 | 23220044 |
| chemical composition and efficacy of dichloromethane extract of croton sphaerogynus baill. (euphorbiaceae) against the cattle tick rhipicephalus microplus (acari: ixodidae). | the cattle tick rhipicephalus microplus is widely distributed in tropical and subtropical regions, causing high economic impact on cattle production. the control of tick infestations is regarded worldwide as critical and has been based on the use of organophosphates, synthetic pyretroids, amitraz and recently ivermectin and fipronil. the present study reports the analysis by gas chromatography/mass spectrometry of the constituents of leaf extracts of croton sphaerogynus and results of acaricidal ... | 2013 | 23200750 |
| in vitro diagnosis of the first case of amitraz resistance in rhipicephalus microplus in santo tomé (corrientes), argentina. | in argentina, the cattle tick rhipicephalus microplus has already developed resistance to organophosphates and synthetic pyrethroids. however, no cases of amitraz resistance have ever been recorded in this country despite its heavy use. a recent failure of amitraz to control ticks in a farm located in santo tomé, province of corrientes, resulted in the collection of samples for acaricide resistance diagnosis. the modified drummond adult immersion test (ait) and the larval tarsal test (ltt) were ... | 2013 | 23153823 |
| survey of pyrethroids resistance in indian isolates of rhipicephalus (boophilus) microplus: identification of c190a mutation in the domain ii of the para-sodium channel gene. | monitoring acaricide resistance and understanding the underlying mechanisms are critically important in developing strategies for resistance management and tick control. eighteen isolates of rhipicephalus (boophilus) microplus collected from four agro-climatic regions of india were characterized and the resistant data were correlated with bioassay results, esterase enzyme activities and with the presence/absence of point mutation in the para-sodium channel gene. the adult immersion test was stan ... | 2013 | 23092687 |
| first report of fipronil resistance in rhipicephalus (boophilus) microplus of mexico. | five strains of rhipicephalus (boophilus) microplus collected from tamaulipas mexico were tested for resistance against several classes of acaricides commonly used. all were resistant to fipronil. four of five were co-resistant to permethrin and coumaphos in addition to being resistant to fipronil. one strain, el zamora was found multi-resistant to permethrin, coumaphos, fipronil, and amitraz. selection with fipronil for 3 generations produced a resistance ratio of 8.3 and 9.4 at the lc(50) and ... | 2013 | 23026557 |
| understanding the genetic, demographical and/or ecological processes at play in invasions: lessons from the southern cattle tick rhipicephalus microplus (acari: ixodidae). | the southern cattle tick, rhipicephalus microplus, is the ixodid species causing the largest economic losses in tropical agrosystems because of its recurrent invasive success, explosive demography on bovine herds, vector competence for diverse pathogens and frequent development of acaricide resistance. its ecology and the physiological bases of the acaricide resistances it developed, as well as alternative tick control measures, have been intensively studied for decades. by contrast, the tick po ... | 2013 | 22945880 |
| 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 ... | 2012 | 22846590 |
| 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 ... | 2012 | 22797607 |
| 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 ... | 2012 | 22766309 |
| 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 ... | 2012 | 22750410 |
| 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 ... | 2012 | 22679862 |
| 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 ... | 2012 | 22647463 |
| 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 ... | 2012 | 22608349 |
| 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 ... | 2012 | 22584130 |
| 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 ... | 2012 | 22549026 |
| 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 ... | 2012 | 22534940 |
| 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 ... | 2012 | 22534937 |
| 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 ... | 2012 | 22521592 |
| 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 ... | 2012 | 22516644 |
| 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 ... | 2012 | 22493861 |
| 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 ... | 2012 | 22424918 |
| 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 ... | 2012 | 22366320 |
| 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 ... | 2012 | 22349940 |
| 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 ... | 2012 | 22343017 |
| genetic basis and impact of tick acaricide resistance. | acaricide resistance in boophilus microplus has been studied for the last 20 years from the toxicology, metabolic and genomic points of view, however, only few methods for molecular detection of resistance have been developed. despite the relatively poor sensitivity for resistance detection, bioassays remain the method of choice for susceptibility evaluation of tick populations, based on their toxicological response after exposure to acaricides. metabolic detoxification of acaricides is known to ... | 2009 | 19273225 |
| differential response to diazinon and coumaphos in a strain of boophilus microplus (acari: ixodidae) collected in mexico. | boophilus microplus, collected from nuevo leon, mexico, were found to be highly resistant to diazinon but not highly resistant to coumaphos, suggesting that different mechanisms of resistance were present in these ticks than other mexican organophosphate (op)-resistant ticks reported previously. when exposed to coumaphos and piperonyl butoxide or triphenylphosphate, the lcso estimate was reduced by 3.5- and 6.3-fold, respectively, suggesting that mono-oxygenases and/or esterases were involved in ... | 2008 | 18826034 |
| [expression and enzymatic activity of glutathione s-transferase in tissues of boophilus microplus females]. | cellular detoxification and excretion enzymes are important to the maintenance of cellular homeostasis. in this work mrna transcription, protein expression and enzymatic activity of glutathione s-transferases (gsts), enzymes involved in the excretion of endo and xenobiotic compounds were analyzed. these parameters are elements believed to protect cells against chemical toxicity and oxidative stress in different tissues (salivary gland, ovary and synganglion) from partially engorged females and e ... | 2008 | 18823578 |
| effect of surface area to weight ratio of egg masses on the hatchability of boophilus microplus eggs. | on global basis, ticks transmit a number of pathogens than any other arthropod vector, and are among the most important vectors of diseases affecting humans, livestock and companion animals. control of the vector has been focused on integrated management involving strategic use of insecticides, use of vaccines, use of herbal acaricides and breed resistance. it has been established that tick vaccine is working on limiting the egg laying potentiality and subsequent hatchability of the ticks fed on ... | 2008 | 18592846 |
| critical evaluation of the modified-adult immersion test with discriminating dose bioassay for boophilus microplus using american and australian isolates. | similar adult immersion tests (aits) for acaricide susceptibility of boophilus microplus were done in texas, usa (muñoz strain) and in queensland, australia (n-strain and ultimo isolates). engorged adult female ticks were immersed in one of a series of dilutions of commercial acaricide in water and then incubated at room temperature for 7 days. data on oviposition were collected 7 days after exposure to acaricide and subjected to probit analysis. for most data, we observed poor fit to the probit ... | 2007 | 17433549 |
| a comparison of three bioassay techniques to determine amitraz susceptibility in boophilus microplus (acari: ixodidae). | the ability of the miller, soberanes, and white bioassay techniques to describe amitraz susceptibility in three different strains of boophilus microplus (canestrini) (acari: ixodidae) was compared. for a susceptible strain, all techniques adequately described amitraz susceptibility by producing a full range of mortality that corresponded with increasing concentration of amitraz. however, when resistant strains were evaluated, only the miller and the soberanes techniques adequately estimated the ... | 2007 | 17427698 |
| cell death during preoviposition period in boophilus microplus tick. | programmed cell death (pcd) is present during the development of multicellular organisms and occurs from embryogenesis to death. in females of boophilus microplus, the mass of several organs is reduced after the detachment from the host. in order to better characterize the cell death process that eliminates unnecessary tissues, the degeneration of salivary glands, ovaries and synganglia was investigated using dna fragmentation in agarose gel, comet and tunel assays, and apoptosis activation path ... | 2007 | 17157985 |
| glucose metabolism during embryogenesis of the hard tick boophilus microplus. | glucose metabolism plays an essential role in the physiology and development of almost all living organisms. in the present study we investigated glucose metabolism during the embryogenesis of the hard tick boophilus microplus. an increase in glucose and glycogen content during the embryonic development of b. microplus was detected and shown to be due to the high enzyme activity of both gluconeogenesis and glycolytic pathways. glucose 6-phosphate (g-6p), formed by hexokinase, is driven mainly to ... | 2007 | 16904922 |
| kinetics of energy source utilization in boophilus microplus (canestrini, 1887) (acari: ixodidae) embryonic development. | the present work evaluates the kinetics of utilization of the main potential energy sources throughout the embryonic developmental stages of boophilus microplus. the embryonic development of this arthropod is completed in 21 days. cellularization of the blastoderm occurs on the 6th day and is rapidly followed by germ band extension and segmentation, whose first signs are visible on the 7th day. cellularization is typically a maternal-driven process, carried out by molecular determinants deposite ... | 2006 | 16569482 |
| [isolation of aspartic proteinases at different stages of development of boophilus microplus tick]. | the magnitud of tisular expression of aspartic proteinases at juvenile stages was analyzed in adult young boophilus microplus ticks as well as the effect of one of the most widely used aspartic proteinase inhibitors (pepstatin a) on their development. the isolation and quantification of acid proteolytic activity was performed in samples of parasites with different stages of the digestive process where aspartic-proteinase activity was confirmed and a tendency to increased values of enzymatic acti ... | 2009 | 15846917 |
| identification of a third boophilus microplus (acari: ixodidae) cdna presumptively encoding an acetylcholinesterase. | oligodeoxynucleotide primers, based on amino acid sequences conserved in known acetylcholinesterases (aches), were used in reverse-transcription polymerase chain reaction (rt-pcr) with mrna from boophilus microplus (canestrini) as the template. primer walking and rapid amplification of cdna ends (race) techniques were used to complete the cdna sequence identified by rt-pcr. the complete b. microplus cdna sequence contained an open reading frame encoding a 620 amino acid protein with a 20 amino a ... | 2004 | 15185924 |
| anti-tick effects of melinis minutiflora and andropogon gayanus grasses on plots experimentally infested with boophilus microplus larvae. | our objective in this trial was to investigate the anti-tick effects of molasses grass (melinis minutiflora) and gamba grass (andropogon gayanus) against boophilus microplus, using buffel grass (cenchrus ciliaris) as a control. during a 3-year-period fieldwork was carried out in the tropical, subhumid climate at progreso, municipality of jiutepec, morelos, mexico. experimental plots were established for three treatments with six replicates under a random factorial design in order to evaluate eac ... | 2004 | 15176734 |
| proteolytic activity of boophilus microplus yolk pro-cathepsin d (byc) is coincident with cortical acidification during embryogenesis. | in a previous report (parasitology 116 (1998) 525) we isolated and characterized boophilus yolk pro-cathepsin (byc), an aspartic proteinase precursor from the eggs of the hard tick. the present study was designed to characterize the function of byc in the consumption of vitellin (vt), the major yolk protein, during embryogenesis. both purified byc and total egg homogenate proteolytic activity showed a similar ph dependence profile with an acidic optimum. purified byc presented higher activity ag ... | 2004 | 15110865 |
| help, a heme-transporting lipoprotein with an antioxidant role. | plasma lipoproteins involved in lipid transport are target for free radical-evoked pathological conditions in several mammalian models. the main hemolymphatic protein of boophilus microplus is a heme-binding lipoprotein (help, for heme lipoprotein) that carries dietary heme produced from degradation of vertebrate hemoglobin to tissues of the tick. addition of heme to phospholipid liposomes resulted in intense lipid peroxidation, which was inhibited by addition of help. help prevented lysis of re ... | 2004 | 14976984 |
| molecular and biochemical diagnosis of esterase-mediated pyrethroid resistance in a mexican strain of boophilus microplus (acari: ixodidae). | we examined pyrethroid resistant mexican strains of boophilus microplus using biochemical and molecular tests to determine the mechanisms conferring resistance. permethrin hydrolysis assays and esterase activity gels indicated enhanced esterase-mediated metabolic detoxification in the cz strain, while one other pyrethroid resistant strain, sf, and two pyrethroid susceptible strains had lower levels of permethrin hydrolysis. results from assays using a pcr-based test to detect a pyrethroid target ... | 2002 | 14570139 |
| in vitro efficacy of extracts of melia azedarach against the tick boophilus microplus. | the efficacy of ripe fruit extracts of melia azedarach l. (rutales: meliaceae) was evaluated against the tick, boophilus microplus (canestrini) (acari: ixodidae). ripe fruits of m. azedarach dried and powdered were extracted by soxhlet apparatus successively using hexane, chcl3 and 96% aqueous ethanol. larvae and engorged females were immersed in decreasing concentrations from 0.25% to 0.015% of each extract. the mortality of larvae was evaluated 24, 72 and 168 h after treatment. the effectivene ... | 2003 | 12823842 |
| a boophilus microplus vitellin-degrading cysteine endopeptidase. | here we describe the purification and characterization of a vitellin (vt) degrading cysteine endopeptidase (vtdce) from eggs of the hard tick boophilus microplus. a homogeneous enzyme preparation was obtained by chromatographic fractionation on ion-exchange and gel filtration columns and an autolysis step. this step consisted of incubation of a semipurified enzyme (after the first ion-exchange chromatography) at ph 4.0 that dissociated the enzyme from vt, to which vtdce is naturally tightly asso ... | 2003 | 12636353 |
| comparative inhibition kinetics for acetylcholinesterases extracted from organophosphate resistant and susceptible strains of boophilus microplus (acari: ixodidae). | in this study, acetylcholinesterases (aches) were extracted from two mexican boophilus microplus strains that demonstrated resistance to the organophosphate (op) acaricide, coumaphos, in bioassay. the rate of inhibition of the extracted aches by the diethyl-op paraoxon was determined for two resistant strains and two susceptible strains of b. microplus. the time to inhibition of 50% ache activity was approximately two-fold greater for the resistant strains. kinetic analysis of the interaction of ... | 2002 | 12539837 |
| isolation and identification of an esterase from a mexican strain of boophilus microplus (acari: ixodidae). | a strain of mexican boophilus microplus (cz) collected near coatzacoalcos, veracruz, mexico, exhibits a moderate, but significant, level of permethrin resistance. unlike other highly permethrin resistant strains, the cz strain does not have a mutation within the sodium channel gene that results in target-site insensitivity. however, the cz strain possesses a substantial increase in general and permethrin esterase activity relative to highly permethrin resistant and control strains suggesting the ... | 2002 | 12403427 |
| molecular diagnosis of pyrethroid resistance in mexican strains of boophilus microplus (acari: ixodidae). | polymerase chain reaction (pcr) diagnostic assays were used to identify possible resistance-associated roles of two amino acid substitutions found in pyrethroid resistance-associated genes of boophilus microplus (canestrini). individual larvae from the san felipe target site resistant strain and the coatzacoalcos (cz) metabolic resistant strain were separated into resistant and susceptible groups by larval packet bioassays and analyzed by pcr. a phe --> ile amino acid mutation in the sodium chan ... | 2002 | 12349861 |
| allele frequency and gene expression of a putative carboxylesterase-encoding gene in a pyrethroid resistant strain of the tick boophilus microplus. | we utilized rna northern blot analysis and ribonuclease protection assays (rpa) to study the mrna expression level of a putative carboxylesterase-encoding gene from several strains of boophilus microplus (canestrini). both the northern analysis and rpas indicated that an esterase transcript was more abundant in the pyrethroid resistant strain, coatzacoalcos (cz), compared to a susceptible control strain and a resistant strain whose pyrethroid resistance is mediated through a target site insensit ... | 2002 | 12213237 |
| cloning and partial characterization of a boophilus microplus (acari: ixodidae) glutathione s-transferase. | a cdna of glutathione s-transferase (gst) was isolated from a cdna library of salivary glands of boophilus microplus. the recombinant protein was purified by glutathione affinity chromatography and assayed upon the chromogenic substrate cdnb. the 864 bp cloned fragment was sequenced and showed an open reading frame coding for a protein of 220 amino acids. expression of the gst gene was tested by rt-pcr in tick tissues and larvae mrna. comparison of the deduced amino acid sequence with gsts from ... | 2002 | 12044491 |
| in vitro generation of organophosphate resistant boophilus microplus (acari: ixodidae) cell lines. | three organophosphate resistant boophilus microplus canestrini cell lines were generated by exposing b. microplus viii-scc cell line to incrementally increased toxic concentrations of the acaricide coumaphos. the development of resistance was evidenced by lc50 values elevated over those of control cells. the resistant cell lines selected in higher concentrations of organophosphate, designated c44 and c54, also had significantly slower duplication rates than a resistant cell line selected in lowe ... | 2002 | 11931027 |
| [identification of a neutral protease in the intestine of boophilus microplus with electrophoresis in polyacrylamide gels copolymerized with gelatin]. | a neutral activity of boophilus microplus in the intestine was identified by electrophoresis in polyacrilamide gel copolymerized with gelatin. the maximum of activity was attained at ph 6.0. the highest specific activity at that ph was obtained with casein substrate. the disappearance of this activity was observed in both substrates after the addition of phenylmethylsulphonyl fluoride in the reaction mixtures. it was very interesting to find out an endopeptidase activity with these characteristi ... | 2009 | 11826517 |
| serine proteinase inhibitors from eggs and larvae of tick boophilus microplus: purification and biochemical characterization. | the present study describes the purification, characterization, and comparison of serine proteinase inhibitors during the development of egg and larva phases of the tick boophilus microplus. samples were collected of eggs between the first day of hatching and the beginning of eclosion (defined as el, e2, and e3) and of larvae between the first day of eclosion and the infectant phase (defined as l1, l2, and l3). crude extracts of the samples (2.5% w/v in tris-hci buffer) were analyzed by sds-page ... | 2001 | 11732684 |
| climate warming and changes in habitat suitability for boophilus microplus (acari: ixodidae) in central america. | remote sensing on the basis of avhrr (advanced very high resolution radiometer) satellite imagery was used, together with standard geostatistical methods (cokriging), to estimate the distribution of habitat suitability (hs) for the tick boophilus microplus (canestrini) in central america. most attention was paid to the expected limits of tick distribution as well as the temperature and vegetation values responsible for different hs zones and their variability within the year. the highest hs exte ... | 2001 | 11695419 |
| use of an allele-specific polymerase chain reaction assay to genotype pyrethroid resistant strains of boophilus microplus (acari: ixodidae). | a polymerase chain reaction-based assay was developed to detect the presence of a pyrethroid resistance-associated amino acid substitution in boophilus microplus (canestrini). the assay uses a simple method for the extraction of genomic dna from individual larvae and genotypes individuals for the presence of a phe-->ile amino acid substitution in the s6 transmembrane segment of domain iii of the para-like sodium channel, clearly distinguishing heterozygotes from homozygotes. high frequencies for ... | 2001 | 11268690 |
| isolation and partial characterization of the montecitos strain of boophilus microplus (canestrini, 1877) multiresistant to different acaricides. | | 2000 | 11193697 |
| preliminary results of a larval resistance test to ivermectins using boophilus microplus reference strains. | | 2000 | 11193684 |
| [cathepsin l-like activity in hemolymph of females crammed with boophilus microplus]. | the cysteine-proteinase activity present in the hemolymph of females crammed with boophilus microplus at the second oviposition was proved. the enzyme assay was performed using the synthetic n-carbobenzoxi-phenilalanyl-arginil-4-metoxibetan++ +-naphthylamide substrate, and hydrolysis in both raw ovarim extract and hemolymph were observed. the activity was 100% inhibited by trans-epoxisuscinyl-l-leucidamide (4-guadinine) butane, an specific inhibitor for cysteine-proteinase. polyacrylamide and ge ... | 2009 | 10887589 |
| regionalization of oviducts in boophilus microplus (canestrini, 1887) (acari: ixodidae) and its potential significance for fertilization. | the structural analysis of oviducts in boophilus microplus (canestrini, 1887) in different stages of ingurgitation has indicated that they are constituted primarily of an internal cylinder and an external cylinder with different cell types being found between them. copulated females in active ingurgitation process show typical variations along the internal cylinder, and three regions can be defined: anterior, ring-like and transitional. based on such regionalization, hypotheses were raised about ... | 1999 | 23505653 |
| immunology of the tick-host interaction and the control of ticks and tick-borne diseases. | the first experimental vaccination against ticks was carried out 60 years ago. since then, progress has been slow, although the recent commercial release of a recombinant vaccine against boophilus microplus is significant. the nature of naturally acquired protective immunity against ticks is poorly understood, particularly in the important, domesticated ruminant hosts. characterization of the antigens of naturally acquired immunity remains limited, although more has been achieved with 'concealed ... | 1999 | 10377526 |
| comparison of genomic dna in various strains of boophilus microplus (acari: ixodidae). | the conventional method of identifying acaricide resistance in a suspect tick population by the united nations food and agriculture organization packet assay is a laborious and time-consuming process. dna probes have been demonstrated as rapid and accurate tools for detecting pesticide resistance in insect species. random-amplified polymorphic dna (rapd) has been used by other groups to differentiate species of mosquitoes and populations within a mosquito species. by using different arbitrary ol ... | 1998 | 9775626 |
| carboxydipeptidase from boophilus microplus: a "concealed" antigen with similarity to angiotensin-converting enzyme. | a protein, bm91, which was first identified as a protective vaccine antigen from the tick boophilus microplus, has regions of very strong amino acid sequence similarity to mammalian carboxydipeptidases or angiotensin converting enzymes (ace; e.c. 3.4.15.1). this protein is now shown to share many biochemical and enzymatic properties with mammalian carboxydipeptidases. it is enzymatically active in a conventional assay for ace using hippuryl-gly-gly as substrate. the hydrolysis of the c-terminal ... | 1995 | 8541886 |
| comparative reproduction and nonparasitic development of boophilus microplus and hybridized boophilus ticks (acari: ixodidae) under natural field conditions in subtropical south texas. | the reproductive biology and nonparasitic development of boophilus microplus (canestrini) and hybridized boophilus ticks (b. annulatus (say) male x b. microplus female) held under natural field conditions in south texas throughout the year were compared. comparisons between the two types of ticks indicated that the ovipositional biology (percentage of ovipositing females and number of eggs laid) of the females favored hybrid ticks during some months and b. microplus ticks during other months. ho ... | 1994 | 7628244 |
| studies on the development and survival periods of the non-parasitic stages of boophilus microplus (canestrini), in the climatic conditions of ranchi (india). | engorged female ticks of boophilus microplus were exposed in wire-gauze cylinders and glass tubes in an experimental grass plot at monthly intervals during 1989, and egg laying, egg development and larval survival periods observed and recorded. rainfall and atmospheric relative humidity had an important influence on tick activity. egg production was maximum, hatching percentage was high, incubation and prehatch periods were short, and larval survival and total longevity periods were long for tic ... | 1992 | 1466134 |
| cholinesterase insensitivity: a mechanism of resistance in mexican strains of boophilus microplus (acari: ixodidae) against coumaphos. | | 1988 | 3404542 |
| metabolism of coumaphos in susceptible and resistant strains of boophilus microplus (acari: ixodidae). | | 1988 | 3351878 |
| boophilus microplus (ixodid tick): fine structure of the gut basophilic cell in relation to water and ion transport. | basophilic cells in the guts of female ticks are derived from the basal remnants of type 2 secretory cells. as viewed by electron microscopy, these cells have microvilli uniformly distributed on the luminal surface, but they lack the abundant pinocytotic vesicles and lysosomes characteristic of digest cells. the cytoplasm is filled with well organized rough endoplasmic reticulum, golgi complexes and secretory granules. infoldings of a basal labyrinth extend the contact of the cell with the under ... | 1987 | 3453788 |
| use of taylor's power law in examining the spatial distribution of free-living boophilus microplus (acari: ixodidae) larvae in pastures in puerto rico. | taylor's power law (y = amb) was used to analyze the spatial pattern of boophilus microplus (canestrini) larvae in tropical pastures. the index of aggregation b was 2.75 and showed that larvae were highly aggregated. the b-values differed significantly among certain pastures (lsd, p less than 0.05), and pasture type and use could have contributed to differences in b. the use of taylor's power law to adjust for sampling inconsistencies that occur in tropical pastures where regimented sampling can ... | 1987 | 3453787 |
| scanning electron microscopy of digest cells in the midgut epithelium of boophilus microplus. | scanning electron microscopy showed the presence of microvilli on the digest cells, but more importantly, it showed that the gut could be everted to expose the lumen surface of the cells to molecular analysis. x-ray microanalysis demonstrated the presence of iron and sulphur in the haematin granules within spent digest cells, confirming that these granules are end products of blood digestion in adult ticks. | 1986 | 3451868 |
| scanning electron microscopic observations on the surface structure of the tick boophilus microplus(canestrini, 1887) female specimens. | boophilus microplus (canestrini, 1887) female specimens were subjected to scanning electron microscopy for the observation of surface fine structures. morphological characteristics observed were summarized as follows: the palpi were wider than long, and compressed, ridged dorsally and laterally. there were usually four pairs of ventro-internal setae on the articles. the hypostome dentition was usually 4/4 but occasionally 5/5. the basis capituli were hexagonal dorsally and the porose area was di ... | 1985 | 12888676 |
| sampling efficiency of three dragging techniques for the collection of nonparasitic boophilus microplus (acari: ixodidae) larvae in puerto rico. | | 1985 | 4008746 |
| pharmacology of the octopamine-stimulated adenylate cyclase of the locust and tick cns. | the presence of an octopamine-stimulated adenylate cyclase is shown in homogenates of the cerebral ganglion of the locust schistocerca americana gregaria and the synganglion of the tick boophilus microplus. a detailed study of the pharmacology of the activation of the enzyme of the two species is reported and compared with the pharmacology of octopamine receptors in other invertebrate preparations. | 1984 | 6146464 |
| the efficacy of the drummond adult test on boophilus microplus females (acarina: ixodidae) subjected to various periods of cold storage prior to organophosphate testing. | engorged females of boophilus microplus, stored at 4 degrees c for up to 5 days, and females, kept at room temperature for 1 day and then at 4 degrees c for 1 day, showed no significant differences in their response to an organophosphate as determined by the drummond adult test. | 1983 | 6646662 |
| ultrastructural identification of neurohaemal sites in a tick: evidence that the dorsal complex may be a true endocrine gland. | a fine structural study has been made of the 'paraganglionic plates' associated with the perineurium and of the 'retrocerebral organ' associated with the periganglionic sheath of the tick boophilus microplus; these structures have been postulated, from descriptions by light microscopy, to be tick neurohaemal organs. neurosecretory terminals are observed frequently in the neural lamella/perineurial sheath, particularly in a dorso-lateral area which may correspond to the 'paraganglionic plates'. n ... | 1983 | 6192546 |
| partial characterization of a unique female diploid cell strain from the tick boophilus microplus (acari: ixodidae). | | 1981 | 7288834 |
| susceptibility of brazilian samples of boophilus microplus to organophosphorus acaricides. | this paper describes the susceptibility of various samples of boophilus microplus from the southern region of minas gerais state in brazil to the 4 commonest organophosphorus acaricides employed in the area. all samples showed some degree of resistance to each of the compounds used. the resistance factor varied from 1.42 to 132.90, being less in the case of dicrotophos fenthion than with chlorpyrifos and coumaphos. | 1980 | 6154364 |
| [preliminary note on the appearance of resistance to ethion in several strains of boophilus microplus in new caledonia]. | | 1980 | 7232805 |
| boophilus microplus: characterization of larval phosphomonoesterases and isolation of subcellular fractions with high phosphatase activity. | | 1978 | 78858 |
| metabolism of [14c] amitraz in larvae of boophilus microplus. | amitraz, 1, 5-di(2, 4-dimethylphenyl)-3-methyl-1, 3, 5-triazapenta-1, 4-diene, labelled with 14c in the 2-methyl groups was applied to b. microplus larvae by an immersion technique. the chemical penetrated readily but never appeared in large amounts internally due to rapid cleavage to n-2, 4-dimethylphenyl-n'-methylformamidine. the expected complementary cleavage product 2, 4-dimethylformanilide was not produced in equivalent quantity. however, large amounts of polar metabolite(s) were produced. ... | 1978 | 678221 |
| virus-like particles pathogenic to salivary glands of the tick boophilus microplus. | | 1978 | 628429 |
| boophilus microplus: strain differences of the cholinesterase system. | | 1978 | 23955 |
| boophilus microplus: characterization of larval proteases. | | 1978 | 23954 |
| the innervation of the salivary gland of the tick, boophilus microplus. | salivary of the ixodid tick boophilus microplus canestrini are at least partially innervated by a branch of the pedipalpal nerve. axons containing both large granular and smaller agranular vesicles were observed within the acini associated with all types of secretory cells. a modification of the falk-hillarp histochemical technique was used to demonstrate discrete areas of fluorescence within the salivary acini. it is suggested that the transmitter involved with the control of salivary activitie ... | 1977 | 22402 |
| [the ixodicidal activity of clenpyrin, chlordimeform and chlormethiuron against op-resistant boophilus microplus strains]. | | 1976 | 1266446 |
| oviposition of boophilus microplus (canestrini) (acarida: ixodidae). iii. oviposition pattern of acaracide resistant strain. | | 1975 | 1179949 |
| resistance in boophilus microplus to cholinesterase inhibition and alterations in the site of action. | | 1975 | 1063661 |
| dopamine and noradrenaline in the salivary glands and brain of the tick, boophilus microplus: effect of reserpine. | | 1974 | 4435160 |
| the soluble cuticular proteins form three arthropod species: scylla serrata (decapoda: portunidae), boophilus microplus (acarina: ixodidae) and agrianome spinicollis (coleoptera: cerambycidae). | | 1974 | 4214646 |
| oviposition of boophilus microplus (canestrini) (acarida: ixodidae). ii. influence of temperature, humidity and light. | | 1974 | 4466310 |
| oviposition of boophilus microplus (canestrini) (acarida : ixodidae). i. influence of tick size on egg production. | | 1974 | 4463680 |
| culture of embryonic cells from the tick boophilus microplus (ixodidae). | | 1973 | 4760627 |
| an experimental investigation into the effects of flooding on the ixodid tick boophilus microplus (canestrini). | the effect of water immersion on the non-parasitic stages of boophilus microplus were investigated both under laboratory and field conditions. survival of engorged female ticks was influenced by their age and the temperature of the water. eggs and larvae were more resistant to submerison than were engorged females and their survival was increased at low temperatures and in water with high oxygen content. the persistence of this tick in areas prone to flooding was attributed to the survival of pa ... | 1971 | 28310970 |
| new types of organophosphorus-resistant ticks (boophilus microplus). | | 1971 | 5102657 |
| the mechanism of feeding and salivation in boophilus microplus (canestrini, 1887). | | 1971 | 5565392 |
| development and survival of the tick boophilus microplus (can.) in laboratory and under natural conditions of cuba. | | 1971 | 5163210 |
| cholesterol in the cuticular wax of boophilus microplus. | | 1969 | 5786195 |
| [further observations in madagascar on the resistance of the tick boophilus microplus (canestrini) to insecticides of the chlorinated hydrocarbon family]. | | 1967 | 5614032 |
| [study of livestock ticks in guadeloupe and martinique. 3. resistance of the boophilus microplus tick to gammexane in the french antilles]. | | 1967 | 4177893 |
| culture of an organophosphorus-resistant strain of boophilus microplus (can.) and an assessment of its resistance spectrum. | | 1966 | 5945563 |