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localisation and characterisation of ovine immunglobulin within the sheep scab mite, psoroptes ovis.ovine igg was detected in homogenates of repeatedly washed psoroptes ovis. some of the immunoglobulin in the homogenates was fragmented although the host igg present in mite washings was largely intact. the host immunoglobulin was immuno-localised to the surface or cytoplasm of the gut cells of feeding stages of freshly harvested p. ovis examined by cryosectioning. a similar distribution of rabbit igg was detected in p. cuniculi. the igg demonstrated in the mite gut represented partially digeste ...200010760413
the complete mitochondrial dna sequence of the horseshoe crab limulus polyphemus.we determined the complete 14,985-nt sequence of the mitochondrial dna of the horseshoe crab limulus polyphemus (arthropoda: xiphosura). this mtdna encodes the 13 protein, 2 rrna, and 22 trna genes typical for metazoans. the arrangement of these genes and about half of the sequence was reported previously; however, the sequence contained a large number of errors, which are corrected here. the two strands of limulus mtdna have significantly different nucleotide compositions. the strand encoding m ...200010779542
resistance of holstein-friesian cows to infestation by the cattle tick (boophilus microplus).in two experiments, the milk production of 59 holstein-friesian cows in mid lactation was measured over 1 week before artificial infestation with 2,500 or 5,000 boophilus microplus larvae. host resistance, the proportion of female ticks applied but not engorging was estimated from weekly counts of engorging female ticks of 4.5-8. 0mm long. mean host resistance was 79 and 67% in two experiments. host resistance was not significantly related to milk yield before infestation, to early pregnancy, or ...200010799843
cloning, characterization, and expression of a 200-kilodalton diagnostic antigen of babesia bigemina.current serological tests for babesia bigemina use semipurified merozoite antigens derived from infected erythrocytes. one of the major drawbacks of these tests is that antigen quality can vary from batch to batch. since the quality of the antigen contributes to the sensitivity and specificity of serological tests, the use of standardized recombinant antigens should ensure consistency in assay quality. previously, a 200-kda merozoite antigen (p200) was identified as a candidate diagnostic antige ...200010834983
development of vaccines against gastrointestinal nematodes.vaccination against complex metazoan parasites has become a reality with the development and registration of recombinant protein-based vaccines against the cattle tick boophilus microplus and the sheep cestode taenia ovis. progress towards the development of similar vaccines against gastrointestinal nematodes, primarily of ruminants, is outlined within a framework of defining the practical requirements for successful vaccination, antigen selection, recombinant protein production and antigen deli ...200010874709
report on ticks collected in the southeast and mid-west regions of brazil: analyzing the potential transmission of tick-borne pathogens to man.specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the southeast and mid-west regions of brazil. nine species of amblyommidae were identified: anocentor nitens, amblyomma cajennense, amblyomma ovale, amblyomma fulvum, amblyomma striatum, amblyomma rotundatum, boophilus microplus, boophilus annulatus, and rhipicephalus sanguineus. the potential of these tick species as transmitters of pathogens to man was analyzed. a flaviviridade flavivirus ...199910881097
a heme-binding aspartic proteinase from the eggs of the hard tick boophilus microplus.an aspartic proteinase that binds heme with a 1:1 stoichiometry was isolated and cloned from the eggs of the cattle tick boophilus microplus. this proteinase, herein named thap (tick heme-binding aspartic proteinase) showed pepstatin-sensitive hydrolytic activity against several peptide and protein substrates. although hemoglobin was a good substrate for thap, low proteolytic activity was observed against globin devoid of the heme prosthetic group. hydrolysis of globin by thap increased as incre ...200010896678
identification of a point mutation in an esterase gene in different populations of the southern cattle tick, boophilus microplus.two esterase cdna sequences were obtained from susceptible and organophosphorus resistant strains of boophilus microplus. both sequences have a high degree of homology to carboxylesterase b. one gene has identical sequences in both strains and the other showed two point mutations. one mutation produces an amino acid substitution when the amino acid sequence is deduced, this mutation was detected in six different populations susceptible and resistant to insecticides, but a pyrethroid resistant st ...200010899463
a review of the ticks (acari, ixodida) of brazil, their hosts and geographic distribution - 1. the state of rio grande do sul, southern brazil.a review of the ticks (acari, ixodida) of the state of rio grande do sul, southern brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. the ticks: argas miniatus (poultry), ixodes loricatus (opossums), amblyomma aureolatum (dogs), a. calcaratum (anteaters), a. cooperi (capybaras), a. nodosum (anteaters), a. tigrinum (dogs) (neotropical) and rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, afrotropical) were ...200010904399
lectin activity from the cattle tick (boophilus microplus) saliva.the capability of boophilus microplus saliva (bms) and lectins to induce immunosuppression in mice and to agglutinate erythrocytes from distinct animal species were compared. cd-1 mice were distributed into groups (two for each substance) of 4-5 animals/group and treated intraperitoneally (i.p.) with 50 mg and 150 mg of bms; concanavalin a (con a); potato's lectin (pl), striped bean lectin (sbl) or 0.1 ml of phosphate buffered saline (pbs). all mice were immunized i.p. with 2 x 108 sheep erythro ...199710932717
simulation of rotational grazing to evaluate integrated pest management strategies for boophilus microplus (acari: ixodidae) in venezuela.ranchers in venezuela historically have controlled the cattle-fever tick, boophilus microplus (canestrini), with acaricide treatments of cattle but no technical planning. we developed a simulation model to evaluate cattle-tick population dynamics in systematic pasture rotation systems and integrated pest management (ipm) approaches to managing ticks in the tropical dry-forest ecological zone of venezuela. model output showed five generations of cattle-ticks produced each year throughout the dry ...200010946137
babesia bovis and b. bigemina dna detected in cattle and ticks from zimbabwe by polymerase chain reaction.from blood collected from 94 cattle at 12 locations in the eastern and northeastern areas of zimbabwe, dna was extracted and analysed by polymerase chain reaction with primers previously reported to be specific for babesia bigemina and babesia borvis. overall, dna of babesia bigemina was detected in the blood of 33/94 (35%) cattle and dna from b. bovis was detected in 27/58 (47%) of cattle. the prevalence of dna of b. bigemina was significantly higher in young animals (<2 years) (23/46) than in ...200010949512
help, a heme lipoprotein from the hemolymph of the cattle tick, boophilus microplus.the main protein of the hemolymph of the cattle tick boophilus microplus has been isolated and shown to be a heme lipoprotein (help). help has an apparent molecular mass of 354,000 and contains two apoproteins (103 and 92 kda) found in equal amounts. help presents a pi of 5.8 and a density of 1.28 g/ml and contains 33% lipids, containing both neutral lipids and phospholipids, and 3% of sugars. a remarkable feature of help is the abundance of cholesterol ester (35% of total lipids), a lipid not p ...200010964932
cloning and functional expression of a boophilus microplus cathepsin l-like enzyme.a cysteine proteinase gene homologous to cathepsins l genes was isolated from a b. microplus cdna library. the precursor protein deduced from the nucleotide sequence contains 332 amino acid residues consisting of a signal sequence (pre-region), a pro-region and a mature proteinase. the dna fragment coding for the proenzyme was cloned and expressed using the e. coli expression vector pmal-p. the recombinant protein (mbp+procp) once activated is able to hydrolyze synthetic substrates as well as pr ...200010989288
diversity of ectoparasites in sheep flocks in são paulo, brazil.the occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. sheep production used to be a predominantly family activity in the state of são paulo (brazil), but it began to become a commercial activity in the past decade. thus, information about the ectoparasites existing in sheep flocks has become necessary. the present data were obtained by means of questionnaires sent to all sheep breeders belonging to the 'associação paulista de criadores de ovinos' (aspaco; ...200011020945
cloning and transcriptional expression of a leucokinin-like peptide receptor from the southern cattle tick, boophilus microplus (acari: ixodidae).leucokinins are invertebrate neuropeptides that exhibit myotropic and diuretic activity. only one leucokinin-like peptide receptor is known, the lymnokinin receptor from the mollusc lymnaea stagnalis. a cdna encoding a leucokinin-like peptide receptor was cloned from the southern cattle tick, boophilus microplus, a pest of cattle world-wide. this is the first neuropeptide receptor known from the acari and the second known in the subfamily of leucokinin-like peptide g-protein-coupled receptors. t ...200011029664
"identification of a point mutation in an esterase gene in different populations of the southern cattle tick, boophilus microplus" by r. hernandez, h. he, a. c. chen, s. d. waghela, g. w. ivie, j. e. george and g. g. wagner. insect biochemistry and molecular biology 30(10) pp.969-977 200011044668
in vitro assessment of metarhizium anisopliae isolates to control the cattle tick boophilus microplus.metarhizium anisopliae is a filamentous fungus used for tick control. the in vitro effects of 12 m. anisopliae isolates on engorged boophilus microplus females were analysed. the most pathogenic isolate (e6s1) caused a 100% death rate when 10(7) spores/ml were used to infect ticks. isolates of m. anisopliae taken from experimentally infected ticks proved to be more pathogenic than fungus maintained on culture media. a comparison between dsrna mycovirus-free and infected m. anisopliae isolates su ...200011078949
localisation and functional studies on the 5'-nucleotidase of the cattle tick boophilus microplus.the ecto-5'-nucleotidase from the cattle tick boophilus microplus is an unusual enzyme, hydrolysing a variety of nucleoside mono-, di- and triphosphates to release the free nucleoside. the gene has been sequenced and the recombinant protein expressed as a functional, active enzyme. nevertheless, the function of the enzyme in the tick remains obscure. the enzyme is present throughout the life cycle, but in largest amounts in unfed larvae and adult ticks. the tissue location has been studied in ad ...200011108389
ticks (acari: ixodidae) associated with wild animals in the pantanal region of brazil.this paper describes the identification of ticks from wild animals of the pantanal region in brazil as part of a comprehensive study about established and emerging tick-host relationships and related pathological aspects. eighty-one animals were captured (representing 13 species, six orders), and ticks were found on 63 (78%). tick species identified included boophilus microplus (canestrini), amblyomma cajennense (f.), amblyomma parvum aragão, amblyomma pseudoconcolor aragão, amblyomma scalpturat ...200011126563
seasonal variation of boophilus microplus (canestrini, 1887) (acari: ixodidae) in cattle in minas gerais state, brazil.the seasonal variation of the tick boophilus microplus in the 'região metalúrgica' region of minas gerais state was studied using 26 bos taurus (holstein) x bos indicus (gir) calves, of which 16 animals were 3/4 holstein x 1/4 gir and 10 were 3/4 gir x 1/4 holstein. monthly tick counts were made between march 1996 and march 1998 and, although b. microplus infestations occurred throughout the year, they were greater during the rainy season. rainfall was the climatic factor that most affected the ...200011147277
boophilus microplus anticoagulant protein: an antithrombin inhibitor isolated from the cattle tick saliva.an anticoagulant was isolated from saliva of the cattle tick boophilus microplus. crude saliva prolonged both recalcification time and prothrombin time in assays with bovine plasma. it also inhibited thrombin, but not fxa, amidolytic activity. we purified the antithrombin activity by a combination of gel filtration, anion exchange, and affinity chromatography. the purified inhibitor has a molecular weight of 60,000 da, determined by sds-page. the anticoagulant ic50 varied from 100 nm to 1.1 micr ...200011147837
lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis.although borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing lyme disease or relapsing fever remains undescribed. we tested the previously published hypothesis that spirochetes infecting lone star ticks (amblyomma americanum) may comprise b. theileri by analyzing the 16s ribosomal dnas (rdnas) and flagellin genes of these spirochetes. b. theileri, the amblyomma agent, and b. miyamotoi formed a natural gro ...200111158095
tests to determine lc50 and discriminating doses for macrocyclic lactones against the cattle tick, boophilus microplus.laboratory tests were carried out on larvae and adults of the cattle tick boophilus microplus to determine the toxicity of macrocyclic lactone acaricides (mls). technical and commercial mls were used in larval packet test (lpt), larval immersion test (lit) and adult immersion test (ait). in lit and ait the toxicity of mls was much higher than for lpt. in the ait, diluting the injectable formulation of mls in water was as effective as dilution in ethanol+triton x-100. lc50, lc99.9 and 95% confide ...200111163698
feeding of hard ticks in vitro: new perspectives for rearing and for the identification of systemic acaricides.experiments on in vitro feeding of the hard ticks ixodes ricinus, boophilus microplus, amblyomma variegatum and amblyomma hebraeum are described. an in vitro test for systemic acaricides is presented. work started with a feeding chamber continuously supplied with new blood. it proved too susceptible to fungal contamination and not efficient enough. simple feeding units made of honey jars with an inner glass tube were far more practical. reinforced silicone membrances or baudruche membrances impr ...199611178446
ticks associated with wild animals in the nhecolândia pantanal, brazil.a study of ticks associated with wild animals was carried out from september 1996 to april 1998 at the fazenda alegria (21,000 ha), in the nhecolândia pantanal, state of mato grosso do sul, brazil, a sunken plain bordering the upper paraguay river, located 19 x 08's; 56 x 46'w. a total of 81 wild animals (13 species, 6 orders) were captured with the aid of nets, and ticks were found on 63 (78%). tick species identified included boophilus microplus (canestrini), amblyomma cajennense (f.), a. parv ...200011193635
thermal constant estimation in tropical horse tick, anocentor nitens (acari:ixodidae).experience has demonstrated that the exclusive use of acaricides as a control method against cattle ticks causes several problems, and is not totally effective. other methods need to be added in order to achieve better and more profitable control of these parasites. groups of 12 to 15 engorged ticks, bred on bovines, were individually incubated at six temperatures (t = 24, 26, 28, 30, 32, and 34 degrees c) and four relatives humidities (rh = 100, 80, 75.5, and 70%), creating 24 variants. the ons ...200011193636
artificial feeding in boophilus microplus (acari:ixodidae) through micropipettes.newly molted boophilus microplus females obtained in a laboratory at 30 degrees c and environmental relative humidity (rh) were employed. an original device was used to hold ticks during feeding. three groups of 15 ticks each were created: unfed, fed with heparinized blood, and fed with defibrinated blood. ticks were weighed before and after feeding. females were restricted by group in three isolators attached on the skin of a bovine. ten sexually competent males were added to each isolator. tim ...200011193640
babesiosis (babesia bovis) stability in unstable environments.enzootic stability (herd immunity) in bovine babesiosis occurs when the rate of transmission (inoculation rate) of babesia spp by the tick vector is sufficient to immunize a majority of susceptible calves before the loss of calfhood resistance. the effect of three tick (boophilus microplus) control strategies (none, threshold, and strategic) on enzootic stability and the likelihood of babesiosis (babesia bovis) outbreaks was studied using a spreadsheet age-class computer simulation model. the mo ...200011193666
skin test and tick immune status in susceptible and resistant cattle in brazil.a cutaneous hypersensitivity test (cht) was used to correlate host resistance to ticks and type of reaction elicited to unfed larval extract-ule of the cattle tick boophilus microplus in european and indian cattle. twenty calves were separated into four groups of five animals each: naïve or preinfested indian or european cattle. cht was induced by intradermal inoculation of 0.1 ml of ule cattle tick b. microplus (50 micrograms protein) in the calf ear. ear thickness was measured using calipers b ...200011193675
immunological control of ticks through vaccination with boophilus microplus gut antigens.the control of tick infestations and the transmission of tick-borne diseases remain a challenge for the scientific community. traditional control methods have been only partially successful. recently, vaccination with recombinant boophilus microplus gut antigens has been shown to control tick infestations. our bm86-containing vaccine formulation (gavac) has been effective for the control of artificial infestations of b. annulatus, b. decoloratus, and chemically sensitive and resistant b. micropl ...200011193686
immune response of naïve cattle to successive infestations of boophilus microplus ticks. 200011193692
experimental infestation of llamas (lama glama) with boophilus microplus (acari:ixodidae).two llamas (lama glama) were infested with approximately 20,000 boophilus microplus larvae each and maintained under controlled conditions to collect the detached adult ticks. a total of 72 engorged and semi-engorged females were recovered with a mean weight of 163.0 +/- 70.6 mg. sixty-three (87.5%) of these ticks oviposited and 60 (95.2%) of the egg masses produced larvae. six of the heaviest females laid 18,838 eggs from which 16,545 (87.8%) hatched. these results show that llamas are able to ...200011201357
immunoglobulin-binding proteins in ticks: new target for vaccine development against a blood-feeding parasite.humans have a long history of trying to control ticks. at first, attempts focused on modifying the habitat, whereas later efforts relied heavily on the use of chemicals. current research is directed at finding a vaccine against ticks. a strategy of targeting 'concealed antigens' succeeded with the first commercialised vaccine against the cattle tick boophilus microplus. however, vaccine development against other tick species appears unsatisfactory to date. vaccination depends on a specific antib ...199911212356
heme biosynthesis and oogenesis in the blood-sucking bug, rhodnius prolixus.we have previously shown that the pathway of porphyrin synthesis operates in the blood feeding triatomine bug rhodnius prolixus but not in the cattle tick boophilus microplus. in the present paper we studied the correlation between heme synthesis and egg development in rhodnius. there is a sharp increase heme biosynthetic capability in the fat body (160%) and in the ovaries (360%) in response to a blood meal, as evaluated from the activity of the enzyme delta-aminolevulinate dehydratase (ec 4.2. ...200111222945
parasitic vaccines: an utopia or reality?major advances in biotechnology over the past decade have led to significant progress in antigen selection, recombinant protein production and antigen delivery in a number of host-parasite systems. vaccination against complex metazoan parasites has become a reality with the development of recombinant vaccines against the cattle tick boophilus microplus and the sheep cestode taenia ovis. in the present paper progress towards the development of similar vaccines against other parasites is discussed ...200111284387
development of an enzyme-linked immunosorbent assay for detection of igm antibodies to babesia bigemina in cattle.a crude antigenic preparation of babesia bigemina was used to develop an elisa for the detection of igm antibodies. optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkerboard titrations. negative sera from cattle imported from tick-free areas, serum samples collected from infected b. bigemina cattle were used to validate the test. the specificity was 94% and sensitivity of the elisa 87.5%. sera from 385 cattle deriving from areas free from tick- ...200111285503
risk factors to tick infestations and their occurrence on horses in the state of são paulo, brazil.from december 1998 to march 1999, 40 stud farms were studied in the state of são paulo, brazil. during visits to farms, horses reared under grazing conditions were examined for the presence of ticks. on each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the f ...200111337122
microsatellite loci of the cattle tick boophilus microplus (acari: ixodidae).this brief communication reports the identification of microsatellite loci in the economically important tick species boophilus microplus. the data are potentially useful in distinguishing different strains of b. microplus. eight polymorphic loci were isolated in larvae, male and female adults analysed individually from 12 field isolates and laboratory strains from australia (n = 8), brazil, mexico, papua new guinea and zimbabwe. nucleotide sequencing of alleles at these microsatellite loci reve ...200011354622
the evaluation of yeast derivatives as adjuvants for the immune response to the bm86 antigen in cattle.the gavac vaccine against the cattle tick boophilus microplus has proven its efficacy in a large number of controlled and field experiments. however, this vaccine could be further improved by searching for new alternative adjuvants that would induce a stronger long-lasting immune response. we conducted several experiments to assay the adjuvant effect of fractions of the recombinant yeast pichia pastoris in mouse and cattle models. in previous experiments, the combination of the yeast membrane wi ...200111399206
the vulnerability of animal and human health to parasites under global change.the term 'global change' is used to encompass all of the significant drivers of environmental change as experienced by hosts, parasites and parasite managers. the term includes changes in climate and climate variability, atmospheric composition, land use and land cover including deforestation and urbanisation, bio-geochemistry, globalisation of trade and transport, the spread of alien species, human health and technology. a subset of land use issues relates to the management of protective techno ...200111406142
efficacy of a single whole-body spray treatment of spinosad, against boophilus microplus (acari: ixodidae) on cattle.the efficacy of a single whole-body spray of spinosad, a naturally derived control agent, applied at three concentrations was evaluated against cattle infested three separate times prior to treatment and at four weekly intervals following treatment with boophilus microplus (canestrini). at 0.0167% active ingredient (ai) both tick numbers (1894 ticks per calf) and index of fecundity (if) of females (258.3) were no different than that of the control group. however, spinosad treatment at both 0.05 ...200111445154
observations on the structure and histology of the female genital system of the cattle tick boophilus annulatus (say).female genital system of boophilus annulatus was examined grossly on the day of drop-off from the host and grossly and microscopically on 4th day. it consists of an ovary, 2 oviducts, a common oviduct, a connecting tube, a seminal receptacle, a vagina divided into cervical and vestibular parts, 2 accessory glands and gene's organ. the ovary oocytes undergo excessive growth during the 4 days after drop-off from the host. oocytes accumulate eosinophilic material during growth and undergo histologi ...200111478455
avermectin resistance of the cattle tick boophilus microplus in brazil. 200111488352
role of rusa deer cervus timorensis russa in the cycle of the cattle tick boophilus microplus in new caledonia.two field experiments were conducted to evaluate the efficiency of rusa deer in the development of the cattle tick boaphilus microplus in comparison with that of steers in the same pastures and under the same conditions of infestation. no difference was noted between a mixed steer/deer herd and a pure steer or pure deer herd in the infestation pattern of each host, suggesting that attachment to the alternative host is mechanical and not affected by the simultaneous presence of the primary host o ...200111508531
influence of acaricide resistance on cattle-fever tick (boophilus spp.) infestations in semi-arid thornshrublands: a simulation approach.cattle-fever tick (boophilus microplus and b. annulatus) populations that develop acaricide resistance become more difficult to control or eradicate. we used a simulation model to assess the direct and indirect effects of interactions among season, habitat type, grazing strategy, and acaricide resistance on the ability to eradicate boophilus infestations in semi-arid thornshrublands of texas, usa. season of infestation appeared to have the strongest effect, with infestations begun on 27 septembe ...200111513366
parasite vaccines--a reality?over the last decade, the anti-parasitics market has been the fastest growing sector of the overall $18 billion animal health market. while drugs for the treatment of parasites of livestock still dominate this sector and will continue to be developed or re-formulated, because of consumer demands for chemical-free food and of concerns regarding the environment and animal welfare there is a growing interest in the development of safe and effective vaccines. there is also a call for vaccines in the ...200111516584
evidence for the utility of the bm86 antigen from boophilus microplus in vaccination against other tick species.the bm86 antigen, as originally identified in boophilus microplus, is the basis of commercial tick vaccines against this tick species. the potential for using this antigen or homologues of the antigen in vaccination against other tick species has been assessed. we have conducted vaccine trials in cattle using the b. microplus-derived recombinant bm86 vaccine (tickgard) using pairs of vaccinated calves and control calves. these were infested with b. microplus and boophilus decoloratus larvae simu ...200111523920
pathogenicity of four strains of entomopathogenic fungi against the bovine tick boophilus microplus.to evaluate the pathogenicity of 4 strains of the entomopathogenic fungi metarhizium flavoviride var flavoviride and metarhizium anisopliae var anisopliae in vitro against the bovine tick boophilus microplus.200111560280
in vivo evaluation of amitraz against ticks under field conditions in ethiopia.an aqueous emulsion of amitraz (bovitraz, bayer ah), prepared and applied according to the manufacturer's recommendations, was evaluated for its activity against cattle ticks on a dairy farm in ethiopia. eight crossbred heifer calves aged between 6 and 8 months and heavily infested with ticks were selected and divided into equal treatment and control groups. the calves in the treatment group were hand-sprayed with the amitraz emulsion while the control group was left untreated. each calf was res ...200111563719
determination of ddt and its metabolites in cattle dip soil available in aqueous phase after remediation.soil taken from a former cattle tick dip site in nsw australia, was remediated with a chemical leaching technology. the pre- and post-remediated soil (20g) was dispersed in water (100ml) and subjected to passive diffusion using polymeric membranes. the remediation reduced tddt from 1174.3 microg/g to 102.9 microg/g (ash weight basis), which was further reduced to 43.2 microg/g with composting. the membranes accumulated 41.3 microg tddt/g from the dip soil, 49.2 microg tddt/g from the chemically ...200111599716
production of reactive oxygen species by hemocytes from the cattle tick boophilus microplus.we have investigated the phagocytic activity and the production of reactive oxygen species (ros) by hemocytes from the cattle tick boophilus microplus. two main types of hemocytes were detected in tick hemolymph: plasmatocytes and granulocytes. the plasmocytes were the most abundant cells, being responsible for the in vivo phagocytosis of yeast. ros production was evaluated by luminol-amplified luminescence and phenol red oxidation. the luminescence increased when hemocytes were incubated with b ...200111748959
reduced oviposition of boophilus microplus feeding on sheep vaccinated with vitellin.the most abundant protein present in boophilus microplus eggs, vitellin, was isolated and purified as a non-covalent complex of six glyco-polypeptides of mr 44-107kda. the protein complex bound haem. immuno-blots demonstrated that antibodies raised to vitellin recognised a 200kda polypeptide in the haemolymph of adult female ticks. this is consistent with the general proposal that in arthropods vitellin is derived by proteolytic processing from a large precursor protein, vitellogenin. in paralle ...200211751009
histochemical localization of esterases in the integument of the female boophilus microplus (acari: ixodidae) tick.the cattle tick boophilus microplus (canestrini) is one of the most important ectoparasites affecting tropical cattle with worldwide distribution. application of organophosphate compounds (op) is extensively used as a tick control method. however, the appearance of ticks resistant to the op decreases the therapeutic efficacy of such compounds. esterases have been implicated as potential biochemical mechanisms for detoxification in b. microplus larvae. we found increased esterase activity in the ...200111761374
molecular cloning and nucleotide sequence of a new p450 gene, cyp319a1, from the cattle tick, boophilus microplus.we have isolated and sequenced a novel p450 gene (cyp319a1) from the cattle tick, boophilus microplus. the cyp319a1 cdna encodes a protein of 531 amino acids with an estimated molecular weight of 60.9k. it contains all highly conserved motifs characteristic of p450 enzymes. comparison of deduced amino acid sequence with other cyp members shows that the cyp319a1 is more closely related to cyp4 family, but its overall identity to the cyp4 family is less than 40%. therefore, it was assigned to a ne ...200211804802
an estimate of the economic effects of cattle tick (boophilus microplus) infestation on queensland dairy farms.to establish the cost to the queensland dairy industry of cattle tick infestation and its control, excluding the costs incurred from control measures directed specifically at tick fever and morbidity and mortality arising from tick fever.200111837904
babesia bovis merozoite surface antigen 1 and rhoptry-associated protein 1 are expressed in sporozoites, and specific antibodies inhibit sporozoite attachment to erythrocytes.we examined babesia bovis sporozoites for the expression of two molecules, merozoite surface antigen 1 (msa-1) and rhoptry-associated protein 1 (rap-1), that are postulated to be involved in the invasion of host erythrocytes. both msa-1 and rap-1 were transcribed and expressed in infectious sporozoites. importantly, monospecific msa-1 and rap-1 antisera each inhibited sporozoite invasion of erythrocytes in vitro. this is the first identification of antigens expressed in babesia sp. sporozoites a ...200211854249
rhodnius heme-binding protein (rhbp) is a heme source for embryonic development in the blood-sucking bug rhodnius prolixus (hemiptera, reduviidae).we have previously shown that rhodnius prolixus' eggs and hemolymph are pink due to the presence of the hemeprotein rhodnius heme-binding protein (rhbp). in the hemolymph it functions as an antioxidant. nevertheless, its function in eggs has not been determined. here we present evidence that rhbp is a source of heme for embryonic development. rhbp content decreases during embryogenesis, but the total heme content of eggs remains unchanged. biliverdin, the product of heme degradation, is not dete ...200211886770
immunodominant epitopes in babesia bovis rhoptry-associated protein 1 that elicit memory cd4(+)-t-lymphocyte responses in b. bovis-immune individuals are located in the amino-terminal domain.babesia bovis rhoptry-associated protein 1 (rap-1), which confers partial protection against b. bovis challenge, is recognized by antibodies and t lymphocytes from cattle that have recovered from infection and are immune to subsequent challenge. rap-1 is a 60-kda protein with an n-terminal (nt) region that contains four cysteine residues conserved among all babesia rap-1 family members and a c-terminal (ct) region that contains multiple, degenerate, tandem 23-amino-acid (aa) repeats. to define t ...200211895969
a single amino acid deletion in the antigen binding site of bola-drb3 is predicted to affect peptide binding.two bovine mhc class ii alleles, bola-drb3*0201 and bola-drb3*3301, contain a three base pair deletion which results in the deletion of a lysine (k beta 65) in the antigen recognition site (ars). modelling of bola-drb3*0201 with the conserved lysine k beta 65 and bola-drb3*0201 without k beta 65 indicated that this deletion altered the peptide specificity of the ars, and may impact on the immune response. to test this hypothesis, the presence of k beta 65 was analysed in a sample of cattle vacci ...200211943314
identification of newly isolated babesia parasites from cattle in korea by using the bo-rbc-scid mice.attempts were made to isolate and identify korean bovine babesia parasite. blood samples were collected from holstein cows in korea, and babesia parasites were propagated in scid mice with circulating bovine red blood cells for isolation. the isolate was then antigenically and genotypically compared with several japanese isolates. the korean parasite was found to be nearly identical to the oshima strain isolated from japanese cattle, which was recently designated as babesia ovata oshimensis n. v ...200211949211
bmti antigens induce a bovine protective immune response against boophilus microplus tick.boophilus microplus trypsin inhibitors (bmtis) present in larvae were preliminarily characterized as active proteins, approximately 10-18 kda, by sds-page. bmtis showed trypsin inhibitory activity on reverse zymography containing gelatin (0.03%) and also inhibited others serine proteinases (human neutrophil elastase and human plasma kallikrein). bos indicus, nelore breed calves, previously sensitized with bmtis and challenged with tick larvae (20,000 larvae/animal), showed 72.8% efficacy to inte ...200211962734
analysis of the sequence and expression of a second putative acetylcholinesterase cdna from organophosphate-susceptible and organophosphate-resistant cattle ticks.the cattle tick, boophilus microplus, is a major pest of cattle in australia, central and south america, and parts of africa and asia. control of ticks with organophosphates (ops) and carbamates, which target acetylcholinesterases (ache), led to evolution of resistance to these pesticides. alleles at the locus studied here, ache2, from op-susceptible female ticks from australia and mexico differed at 46 of 1689 nucleotide positions (20 putative amino acid differences) whereas alleles from three ...200212044498
immunization of cattle with synthetic peptides derived from the boophilus microplus gut protein (bm86).three synthetic peptides (sbm4912, sbm7462 and sbm19733), derived from the bm86 glycoprotein from boophilus microplus gut, were constructed and used to immunize cattle from a tick-free area. the immunized animals received three subcutaneous doses of the peptides, with saponin as adjuvant, at 30-day intervals. the immune response was evaluated by igg elicited against the peptides by the detection of anti-bm86 specific antibodies in situ and by western blotting analysis. after tick challenge, redu ...200212127414
development of vaccines against sea lice.a review of efforts to develop a vaccine against sea lice is presented together with analysis of the rationale behind the approaches and potential future directions. vaccines against the caligid copepod, lepeophtheirus salmonis, have the potential to be a cost-effective means of controlling the infection and avoid many of the disadvantages of medicine treatments. however, research towards such vaccines is in its infancy and approaches so far used have met with little or no success. most strategi ...200212138623
modification of the food and agriculture organization larval packet test to measure amitraz-susceptibility against ixodidae.modifications of exposure time, substrate, and formulation were made to the food and agriculture organization larval packet test (lpt) to determine a combination suitable for measuring the susceptibility of boophilus microplus (canestrini) to amitraz. exposure time influenced the slope of the dose-response when paper was used as a substrate for amitraz. however, time did not influence the dose-response slope when nylon fabric was used as an amitraz substrate. formulated amitraz produced results ...200212144297
dermacentor variabilis and boophilus microplus (acari: ixodidae): experimental vectors of babesia equi to equids.the experimental vector competence of five laboratory-reared ixodid tick species representing three genera [amblyomma americanum (l.), boophilus microplus (canestrini), d. andersoni stiles, d. occidentalis marx, and d. variabilis (say)] for babesia equi (laveran 1901) was evaluated by delayed transfer of male ticks from infected to susceptible equids or by infesting the latter animals with adult ticks previously fed as nymphs on infected equids. after feeding for 5, 6, or 13 d on acquisition hos ...200212144301
expression and immunolocalization of a boophilus microplus cathepsin l-like enzyme.efforts are being undertaken to control tick infestations that cause important economic losses. a cathepsin l-like endopeptidase of boophilus microplus was expressed in escherichia coli; the recombinant enzyme was capable of hydrolysing gelatin, tick vitellin and bovine haemoglobin. in this paper we focus on the expression and local of synthesis of this enzyme in the tick. rt-pcr experiments showed that this endopeptidase is transcribed in the gut of partially engorged tick females. in immunoblo ...200212144697
detection of natural infection of boophilus microplus with babesia equi and babesia caballi in brazilian horses using nested polymerase chain reaction.the potential role of boophilus microplus as a natural tick vector of babesia equi and babesia caballi in brazilian horses was assessed using nested polymerase chain reaction (pcr)-based marker assay. b. equi merozoite-specific 218bp gene fragment was detected in almost 96% of horse blood samples, and 45.3-62.5% of females, eggs, larvae, and nymphs of b. microplus collected from 47 horses at campo grande in the state of matto grosso, brazil. except for the partially-fed female ticks, the b. caba ...200212163246
effect of salivary gland extracts from the tick, boophilus microplus, on leucocytes from brahman and hereford cattle.the effect of salivary gland extract (sge) from boophilus microplus on peripheral blood lymphocytes, neutrophils and monocytes from brahman (bos indicus) and hereford (bos taurus) cattle was investigated. sge (8 micro g) significantly inhibited the proliferation response of lymphocytes to concanavalin a from both brahman and hereford cattle by 89% and 41%, respectively. the difference in inhibition between the two breeds was highly significant (p < 0.01), whilst at 1 micro g of sge, significant ...200212164821
cattle tick (boophilus microplus) in victoria on horses from queensland. 200212180889
simultaneous detection of anaplasma marginale and a new ehrlichia species closely related to ehrlichia chaffeensis by sequence analyses of 16s ribosomal dna in boophilus microplus ticks from tibet.to identify ehrlichial agents in boophilus microplus ticks, dna samples of b. microplus collected from the tibet autonomous region and sichuan province of china were screened by a nested pcr. sixteen of 43 (37%) dna samples of b. microplus from tibet were positive in nested pcr analysis. all 27 samples from sichuan were negative. the screen identified two ehrlichial agents based on different 16s rrna genes that were found after amplifying and sequencing the 5'-end fragments of the 16s rrna genes ...200212202567
isolation of beauveria bassiana and metarhizium anisopliae var. anisopliae from boophilus microplus tick (canestrini, 1887), in rio de janeiro state, brazil.the objective of this work were to isolate and identify strains of entomopathogenic fungi from ingurgitated female boophilus microplus ticks, collected from the soil in the municipality of paracambi, rio de janeiro state, brazil. the ingurgitated females were inoculated in the selective medium oat dodine agar (oda), where 49 colonies of beauveria bassiana (71%) and 20 of metarhizium anisopliae var. anisopliae (29%) were isolated. these isolated strains characterize for the first time in brazil t ...200212206323
cloning and partial characterization of a boophilus microplus (acari: ixodidae) calreticulin.we report the cloning, sequence characterization and expression analysis of a calreticulin (crt) coding cdna of boophilus microplus. crt is a calcium-binding protein involved in multiple cell functions and possibly implicated in parasites host immune system evasion. the crt cdna sequence and its molecular characterization are described. sequence similarity and phylogenetic analyses indicate a close relationship to other arthropod crt sequences. the crt cdna was also expressed in a procariotic sy ...200212243735
efficacy of macrocyclic lactone endectocides against boophilus microplus (acari: ixodidae) infested cattle using different pour-on application treatment regimes.the efficacy of pour-on formulations of three macrocyclic lactone endectocides (moxidectin, ivermectin, and eprinomectin) was evaluated on cattle against boophilus microplus (canestrini) using two different treatment regimes. a single application treatment regime with each endectocide showed that fewer ticks per calf were recovered from all treated calves than from untreated cattle, but the level of control among the three treatments was similar (range; 78.7-87.7%) against all stages of ticks on ...200212349860
cdna cloning, expression and characterization of a boophilus microplus paramyosin.the tick boophilus microplus is a 1-host tick that causes important losses to bovine herds, and protective antigens are being investigated in order to develop vaccines that avoid the use of acaricides. paramyosins are multi-functional invertebrate muscle proteins, whose roles may include host immunomodulation, and seem to be a prominent candidate in a schistosomiasis vaccine. we report here the cloning, expression and characterization of a b. microplus paramyosin (bmprm). sequence analysis of th ...200212358423
babesia bovis merozoite surface antigen 2 proteins are expressed on the merozoite and sporozoite surface, and specific antibodies inhibit attachment and invasion of erythrocytes.the babesia bovis merozoite surface antigen 2 (msa-2) locus encodes four proteins, msa-2a(1), -2a(2), -2b, and -2c. with the use of specific antibodies, each msa-2 protein was shown to be expressed on the surface of live extracellular merozoites and coexpression on single merozoites was confirmed. individual antisera against msa-2a, msa-2b, and msa-2c significantly inhibited merozoite invasion of bovine erythrocytes. as tick-derived sporozoites also directly invade erythrocytes, expression of ea ...200212379726
effect of the association of cattle and rusa deer (cervus timorensis russa) on populations of cattle ticks (boophilus microplus).the wild population of rusa deer (cervus timorensis russa) in new caledonia (south pacific) is nearly as large as the cattle population. the cattle tick is widespread and occurs all year round. opinions are divided on the role of deer in the biological cycle of the tick: i) do they maintain a sustainable tick population that is secondarily available for cattle? ii) do they decrease the infestation of the environment by collecting larvae on the pasture, but preventing their development to the eng ...200212381606
binding and storage of heme by vitellin from the cattle tick, boophilus microplus.we have previously shown (, curr. biol. 9, 703-706) that the cattle tick boophilus microplus does not synthesize heme, relying solely on the recovery of the heme from the diet to make all its hemeproteins. here we present evidence that vitellin (vn(1)), the main tick yolk protein, is a reservoir of heme for embryo development. vn was isolated from eggs at different days throughout embryogenesis. immediately after oviposition, boophilus vn contains approximately one mol of heme/mol of protein. du ...200212429132
babesiosis and heartwater: threats without boundaries.suppose one of your clients from southern florida starts talking about cattle egrets while you are vaccinating her cat. it seems she found a nearly dead egret near the cattle pen a few days ago, picked it up, and noticed a number of what looked like small ticks on the legs. or, suppose you are called out to a small dairy in central texas to look at some cows that are feverish and anemic. the first animal you examine has a few brown ticks attached just under the tail. finally, perhaps you are loo ...200212442575
ticks (acari: ixodidae) associated with domestic dogs in franca region, são paulo, brazil.ticks on 140 domestic dogs from both urban and rural areas of franca region in são paulo state were identified with 102 dogs from urban areas and 38 from rural areas. of urban dogs, 27.5% were infested exclusively by rhipicephalus sanguineus ticks. of the rural dogs, 36.8% were infested with the following tick species: r. sanguineus, boophilus microplus, amblyomma ovale and a. cajennense. mixed infestations included a dog hosting a. cajennense and a. ovale and another with b. microplus and r. sa ...200112455880
distribution and phenology of ixodid ticks in southern zambia.distribution data for epidemiologically important ticks (acari: ixodidae) in the southern province of zambia, one of the main cattle areas of the country, are presented. boophilus microplus (canestrini) was not recorded in southern zambia, whereas boophilus decoloratus (koch) is present throughout the area. new distribution patterns for less economically important ixodid ticks are also discussed. southern zambia is a transition zone because it is the most northern area in africa where mixed rhip ...200212510896
ixodid ticks on cattle belonging to small-scale farmers at 4 communal grazing areas in south africa.ixodid ticks were collected during the period september 1991 to august 1993 from cattle belonging to small-scale farmers utilising 4 communal grazing areas. three of these were in north west province and 1 in mpumalanga province, south africa. ten tick species were collected in north west province and 7 in mpumalanga. the adults of amblyomma hebraeum, rhipicephalus appendiculatus and rhipicephalus evertsi evertsi were most numerous in north west province, while in mpumalanga boophilus decoloratu ...200212515294
cattle tick boophilus microplus salivary gland contains a thiol-activated metalloendopeptidase displaying kininase activity.this work reports on the characterization of a metalloendopeptidase kininase present in boophilus microplus salivary glands. using the guinea pig ileum assay, salivary gland whole extracts (sge) were found to have a potent kininase activity. ion-exchange chromatography separated two kininase activities from sge. the major enzymatic component, eluted at lower ionic strength, was named bookase (boophilus kininase). analysis of the hydrolysis products by capillary electrophoresis identified phe5-se ...200212530211
effect of moxidectin against natural infestation of the cattle tick boophilus microplus (acarina: ixodidae) in the mexican tropics.the study was divided in to two trials and carried out in a ranch in eastern yucatan state, mexico. in the first trial, two groups of 15 bostaurusxbosindicus heifers, 6-12 month of age and naturally infested with boophilus microplus ticks were used. heifers in group 1 were treated with a 1% injectable formulation of moxidectin at the dose of 0.20mg/kg body weight by subcutaneous injection. the other group remained as untreated controls. number of immature and engorging female ticks were assessed ...200312531295
four serine proteinase inhibitors (serpin) from the brown ear tick, rhiphicephalus appendiculatus; cdna cloning and preliminary characterization.while development of an anti-boophilus microplus vaccine is advanced and practical, work on other economically important ticks such as rhipicephalus appendiculatus is still in its infancy. guess pcr primers, designed from a consensus amino acid sequence (navykfg) motif were used with rapid amplification of cdna ends (race) to clone four cdnas encoding serine proteinase inhibitors (serpin) from the brown ear tick rhipicephalus appendiculatus. the four genes designated as r. appendiculatus serpin ...200312535684
functional analysis of a g protein-coupled receptor from the southern cattle tick boophilus microplus (acari: ixodidae) identifies it as the first arthropod myokinin receptor.the myokinins are invertebrate neuropeptides with myotropic and diuretic activity. the lymnokinin receptor from the snail lymnaea stagnalis (mollusca) has been the only previously identified myokinin receptor. we had cloned a g protein-coupled receptor (af228521) from the tick boophilus microplus (arthropoda: acari), 40% identical to the lymnokinin receptor, that we have now expressed in cho-k1 cells. myokinins at nanomolar concentrations induced intracellular calcium release, as measured by flu ...200312542633
regulation of extracellular chitinases and proteases in the entomopathogen and acaricide metarhizium anisopliae.metarhizium anisopliae infects insects and ticks via a combination of specialized structures and cuticle degradation. hydrolytic enzymes are accepted as key factors for the penetration step. the search for pathogenicity determinants has demonstrated that the process is multifactorial. host specificity is an important factor to be addressed. the study of the enzymes produced during infection is important to discover those with a role in the process. to address some of the enzymes that take part d ...200312567244
factors related to cattle infestation level and resistance to acaricides in boophilus microplus tick populations in new caledonia.boophilus microplus, even in the absence of babesiosis, is a major disease of the cattle in new caledonia where the particular farming system associates continental european breeds and a tropical climate tempered by the pacific ocean. in order to have a better understanding of the factors involved in cattle tick infestation, to decrease the possible wastage and use of chemicals and to increase the lifetime of the acaricides, the veterinary authorities investigated the conditions of the chemical ...200312581586
partial strategic tick control within a herd of european breed cattle in the state of rio grande do sul, southern brazil.a trial is described, in the state of rio grande do sul, southern brazil, as one of a series suggested to investigate the effects of strategic but selective acaricide treatments of cattle within herds against boophilus microplus. they are aimed at considering the repercussions of farmer attempts at immediate reductions in acaricide costs and the potential for creation of 'refugia' of untreated ticks. half (group 1) of a small experimental herd of european breed heifers were treated strategically ...200212593589
biochemical detection of esterases in the adult female integument of organophosphate-resistant boophilus microplus (acari: ixodidae).esterase activity was present in the integument of adult female boophilus microplus (canestrini) ticks that are resistant to organophosphates (op). three esterases were purified from adult integument, which hydrolyze the substrates p-nitrophenylacetate and beta-naphthyl acetate after comparison of op-resistant strain and an op-susceptible strains. the esterases purified by ion-exchange chromatography were characterized using different esterase inhibitors; eserine sulfate, diethyl p-nitrophenyl p ...200312597652
antibacterial hemoglobin fragments from the midgut of the soft tick, ornithodoros moubata (acari: argasidae).midgut contents of ornithodoros moubata showed strong antibacterial activity against staphylococcus aureus. a combination of reversed-phase chromatography and mass spectrometric analysis was used to isolate two antibacterial peptides from the tick midgut lumen. partial amino acid sequences by edman degradation of these two peptides showed they are identical with the 1-11 and 3-19 portions of rabbit a hemoglobin. host rabbit a hemoglobin appears to be cleaved between met32 and phe33 to produce th ...200312597657
factors affecting the detachment rhythm of engorged boophilus microplus female ticks (acari: ixodidae) from charolais steers in new caledonia.as in most parts of the world where the cattle tick boophilus microplus is established, resistance of ticks to acaricides occurs in new caledonia. in order to implement laboratory resistance tests on larvae, engorged females collected in suspected farms are necessary. investigations on the detachment schedule of the engorged females were conducted to explain certain field situations such as the lack or scarcity of engorged females on highly infested cattle driven from the pasture to the pen in t ...200312623211
arsenic in australian environment: an overview.the most common source of elevated as concentrations in the australian environment are attributable to anthropogenic activities. mining activities have contributed to the contamination of soil and water primarily in western australia and victoria. however, other anthropogenic activities such as agriculture, forestry and industry have also contaminated soil and water at a localized scale. currently there are over 1000 as contaminated sites previously used as cattle dips for eradicating cattle tic ...200312635829
induction of mosquitocidal activity in mice immunized with anopheles gambiae midgut cdna.vaccines that induce mosquito-killing (mosquitocidal) activity could substantially reduce the transmission of certain mosquito-borne diseases, especially vaccines against african malaria vectors, such as the mosquito anopheles gambiae. to generate and characterize antimosquito immunity we immunized groups of mice with two individual a. gambiae midgut cdnas, ag-aper1 (a secreted peritrophic matrix protein) and agmuc1 (a midgut-bound mucin), and an a. gambiae midgut cdna library from blood-fed mos ...200312654823
a new intracellular pathway of haem detoxification in the midgut of the cattle tick boophilus microplus: aggregation inside a specialized organelle, the hemosome.the hard tick boophilus microplus ingests large volumes of cattle blood, as much as 100 times its own mass before feeding. huge amounts of haem are produced during haemoglobin digestion, which takes place inside acidic lysosomal-type vacuoles of the digest cells of the midgut. haem is a promoter of free radical formation, so haemoglobin digestion poses an intense oxidative challenge to this animal. in the present study we followed the fate of the haem derived from haemoglobin hydrolysis in the d ...200312682102
detection of ehrlichia spp., anaplasma spp., rickettsia spp., and other eubacteria in ticks from the thai-myanmar border and vietnam.a total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the thai-myanmar border and in vietnam. they were tested by pcr to detect dna of bacteria of the order rickettsiales: three anaplasma spp. were detected in ticks collected in thailand, including (i) anaplasma sp. strain anda465, which was considered a genotype of anaplasma platys (formerly ehrlichia platys) and which was obtained from dermacentor aur ...200312682151
hemolymph proteins in ticks.in comparison to insects and crustacea, our knowledge of the predominant hemolymph proteins in ticks is minimal. the hemolymph protein most studied in ticks has been vitellogenin (vg). vg is synthesized by the tick fat body after female adults obtain a blood meal, is released into the hemolymph and is absorbed by developing oocytes as vitellin (vn). much of what we know about vg is from studies of vn. in general, the carbohydrate, lipid and amino acid composition is similar to insects except tha ...200212770100
a method for extraction and analysis of high quality genomic dna from ixodid ticks.currently, no published methods describe the extraction of high molecular weight genomic dna from ixodid ticks (acari: ixodidae) and commonly used methods of extraction are not well adapted for use with members of this family. a method for extraction of minimally degraded genomic dna from ixodid ticks that can be completed in one or two days is described. the method produces dna which is of sufficient size (>24 kb) for use in southern analysis and which is readily digestible by restriction endon ...200312823841
efficacy of various concentrations of coumaphos to control adult, nymphal, and larval stages of an organophosphate-resistant strain of boophilus microplus on infested cattle.to evaluate the efficacy of coumaphos, an organophosphate (op) acaricide, at concentrations up to 2 times higher than the highest concentration required by the us eradication program against all stages of an op-resistant strain of boophilus microplus in experimentally infested cattle.200312828252
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