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At least 19 recordsLinked to original sources
PubMed1975

Repeated oral administration of coumaphos in sheep: interactions of coumaphos with bishydroxycoumarin, trichlorfon, and phenobarbital sodium.

Interactions between treatments with coumaphos, bishydroxycoumarin (an anticoagulane), trichlorfon (an organophosphorous compound), and phenobarbital sodium (an inducer of microsomal enzymes) were investigated in sheep. A daily dose of 2 mg of coumaphos/kg of body weight for 6 days did not affect the plasma enzymes or the antiprothrombinemic effect of bishydroxy-coumarin in wethers. The treatment of ewes with an intravenous (IV) injection of trichlorfon, insufficient to produce significant inhibition of erythrocyte acetylcholinesterase (AChE) activity, appeared to produce additive effects with those produced by subsequent treatment with 4 mg of coumaphos/kg/day. In ewes given 40 mg of phenobarbital sodium/kg for 5 days intraperitoneally (IP), the anticholinesterase effect of 4 mg of coumaphos/kg was significantly reduced and signs of toxicity were not present. Treatment with daily doses of 2 mg of coumaphos/kg for 6 days did not modify the anticholinesterase effect of a 2nd series of treatments given 6 weeks later.

Acetylcholinesterase↗
PubMed2000

Persistence, degradation and leaching of coumaphos in soil.

Dissipation, degradation and leaching of fresh 14C coumaphos, alkylated 14C coumaphos and aged residues of 14C coumaphos from vats were studied in alkaline sandy loam soil in soil columns in the field under subtropical conditions in Delhi for a year. Dissipation, degradation and bound residue formation was more in case of alkali treated coumaphos than fresh coumaphos. After 365 days total residues of fresh coumaphos accounted for 33.25% while that of alkali treated coumaphos was 19.12%. Bound residue formation was almost double in case of alkali treated coumaphos (18.95%) than fresh coumaphos (9.53%) after 150 days followed by release of bound residue in both the cases. The proportion of metabolites 4-methylumbelliferone, chlorferon and potasan collectively was 86.05% in fresh coumaphos extractable residues while the same was 91.74% in alkali treated coumaphos after 365 days. Aged residues from vats containing copper sulphate and buffer were found to be more persistent in soil as total residues remained were 95.58% in comparison with 83.09% total residues of aged residues from vats containing only buffer after 150 days of treatment. Copper sulphate seems to inhibit the degradatiion of coumaphos in soil by microorganisms. Chlorferon was the major metabolite in generally all the samples. Coumaphos did not leach below 10 cm in all the cases.

Biodegradation, Environmental↗
PubMed2002

Development of a simple and sensitive fluorimetric method for isolation of coumaphos-hydrolysing bacteria.

AIMS: To develop a simple, rapid and sensitive fluorimetric assay to detect, isolate and characterize a soil bacterium capable of degrading the organophosphorus pesticide, coumaphos. METHODS AND RESULTS: A high throughput microtitre plate-based method was used to quantify coumaphos hydrolysis by the bacterium. The fluorescent hydrolysis product of coumaphos, chlorferon, was detected at levels as low as 10 nmol l(-1). Incorporation of coumaphos into agar plates allowed the rapid detection of coumaphos-hydrolysing bacteria when exposed to an excitation wavelength of approximately 340 nm. The coumaphos-hydrolysing enzyme could be visualized when bacterial cell extracts were separated on SDS-PAGE, incubated with coumaphos and exposed to an excitation source as above. CONCLUSIONS: This method is 100-fold more sensitive than the currently used spectrophotometric method for coumaphos. SIGNIFICANCE AND IMPACT OF THE STUDY: This is a unique and versatile tool to screen for bacteria possessing phosphotriesterase activity.

Bacteria↗
PubMed2003

Resistance to coumaphos and diazinon in Boophilus microplus (Acari: Ixodidae) and evidence for the involvement of an oxidative detoxification mechanism.

The levels of resistance to two organophosphate acaricides, coumaphos and diazinon, in several Mexican strains of Boophilus microplus (Canestrini) were evaluated using the FAO larval packet test. Regression analysis of LC50 data revealed a significant cross-resistance pattern between those two acaricides. Metabolic mechanisms of resistance were investigated with synergist bioassays. Piperonyl butoxide (PBO) reduced coumaphos toxicity in susceptible strains, but synergized coumaphos toxicity in resistant strains. There was a significant correlation between PBO synergism ratios and the coumaphos resistance ratios. The results suggest that an enhanced cytochrome P450 monooxygenase (cytP450)-mediated detoxification mechanism may exist in the resistant strains, in addition to the cytP450-mediated metabolic pathway that activates coumaphos. PBO failed to synergize diazinon toxicity in resistant strains, suggesting the cytP450 involved in detoxification were specific. Triphenylphosphate (TPP) synergized toxicity of both acaricides in both susceptible and resistant strains, and there was no correlation between TPP synergism ratios and the LC50 estimates for either acaricide. Esterases may not play a major role in resistance to coumaphos and diazinon in those strains. Bioassays with diethyl maleate (DEM) revealed a significant correlation between DEM synergism ratios and LC50 estimates for diazinon, suggesting a possible role for glutathione S-transferases in diazinon detoxification. Resistance to coumaphos in the Mexican strains of B. microplus was likely to be conferred by both a cytP450-mediated detoxification mechanism described here and the mechanism of insensitive acetylcholinesterases reported elsewhere. The results of this study also underscore the potential risk of coumaphos resistance in B. microplus from Mexico to the U.S. cattle fever tick eradication program.

Animals↗
PubMed2002

Effects of fluvalinate and coumaphos on queen honey bees (Hymenoptera: Apidae) in two commercial queen rearing operations.

We conducted research on the potential impacts of fluvalinate and coumaphos on honey bee, Apis mellifera L., queen viability and health. Queens were reared in colonies that had been treated with differing amounts of both fluvalinate and coumaphos. Pre- and posttreatment samples of both wax and bees were collected from all of the colonies and analyzed for total concentrations of fluvalinate and coumaphos. All queens were measured for queen weight, ovarial weight, and number of sperm in the spermathecae. The queens treated with high doses of fluvalinate weighed significantly less than low-dose or control queens, but otherwise appeared to develop normally. The highest fluvalinate concentrations were observed in the wax and queen cells of the high-dose group. The developing queens in colonies treated with as little as one coumaphos-impregnated strip for more than 24 h suffered a high mortality rate. Several of the queens showed sublethal effects from the coumaphos, including physical abnormalities and atypical behavior. The queens exposed to coumaphos weighed significantly less and had lower ovary weights than the control group queens. The highest coumaphos concentrations were observed in the queen cells and wax of the high-dose groups.

Animals↗
PubMed1988

Fate of [14C]coumaphos after dermal application to lactating goats as a pour-on formulation.

Two lactating Nubian goats were dermally treated with [14C]coumaphos (O-[3-chloro-4-methyl-2-oxo-2H-benzopyran-7-yl] O,O-diethyl phosphorothioate) as a 4% active ingredient pour-on formulation. Doses were administered, along the dorsal midline from withers to sacrum, at a rate equivalent to 14 mg of coumaphos/kg of body weight. During the 7 days after treatment, an average of less than 0.1, 4.7, and 1% of the administered dose was eliminated in the milk, urine, and feces, respectively. When goats were killed after 7 days, about 45% of the administered radiocarbon remained on the hair and skin, and this consisted almost entirely of intact coumaphos. Residues in selected tissues collected after 7 days were, in every case, less than 1 mg of coumaphos equivalent/kg of tissue, with highest residues in adipose tissue, followed by residues in kidney and liver. In milk, residue amounts plateaued after about 2 days and remained relatively constant at about 0.1 mg of coumaphos equivalent/kg of milk. Residues in adipose tissue and in milk consisted mainly of unmetabolized coumaphos. In urine, most radiocarbon was present as metabolites of coumaphos, but in feces, most radiocarbon was present as the intact parent compound. Coumaphos was absorbed slowly and at a constant rate after dermal application to lactating goats as a pour-on formulation.

Adipose Tissue↗
PubMed1988

Isolation and characterization of coumaphos-metabolizing bacteria from cattle dip.

Coumaphos, an organophosphate insecticide, is used for tick control in cattle dipping vats along the U.S.-Mexican border. Recently, several vats (problem vats) have experienced a loss of efficacy because of microbial degradation. Three morphologically distinct bacteria (designated B-1, B-2, and B-3) that metabolized coumaphos were isolated from enrichment cultures that were initiated from problem vat dip material. In general, amino acids, pyrimidines, and acetate supported growth; carbohydrates were not utilized. Only B-2 required growth factors. In resting cell experiments, coumaphos was hydrolyzed to diethylthiophosphoric acid and chlorferon by all three isolates. Chlorferon was subsequently metabolized by B-1 and B-2 to alpha-chloro-beta-methyl-2,3,4-trihydroxy-trans-cinnamic acid. Only B-1 produced additional metabolites. Experiments with [benzo ring-labeled U-C]coumaphos or chlorferon demonstrated that B-1 was capable of both mineralizing and incorporating into biomass the aromatic portion of the molecule. The majority of label, however, was recovered in the form of soluble products, including alpha-chloro-beta-methyl-2,3,4-trihydroxy-trans-cinnamic acid. Although B-1 had the capacity to use chlorferon as a carbon source at low concentrations (100 mug/ml), visible growth at higher concentrations (1,000 mug/ml) was not observed. The addition of 400 mug of chlorferon per ml to B-1 cells in the mid-log phase of growth resulted in complete inhibition of growth, while the addition of 100 to 200 mug of chlorferon per ml resulted in partial inhibition. The growth of B-2 and B-3 was inhibited by 100 mug of chlorferon per ml. These data suggest that, although B-1 and, to a lesser extent, B-2 and B-3 are responsible for the primary degradation of coumaphos, other organisms in the enrichment culture may play a secondary role in coumaphos degradation by removing inhibitory products of coumaphos metabolism.

Journal Article↗
PubMed2002

Effects of acute sublethal exposure to coumaphos or diazinon on acquisition and discrimination of odor stimuli in the honey bee (Hymenoptera: Apidae).

Two organophosphate compounds, coumaphos and diazinon, were examined for effects of sublethal exposure on odor learning and generalization in honey bees, Apis mellifera L. Using proboscis extension response training as a measure of odor learning and discrimination, a series of two experiments tested whether these compounds would inhibit bees from learning a new odor or discriminating between different odors. Bees were exposed to coumaphos or diazinon in acetone applied to the thorax, or to coumaphos or diazinon in hexane injected intracranially. At no dose tested or exposure method used was coumaphos shown to inhibit acquisition of a novel odor stimulus, although it was shown to slightly reduce discriminatory ability when given by intracranial injection. Diazinon had effects on odor learning at several small doses, and a small injected dose was shown to significantly inhibit learning of an odor stimulus paired with a sucrose reward. When bee head acetylcholineasterase activity was measured after dermal applications of both pesticides, only the higher doses of diazinon showed reduced activity, indicating that externally-applied coumaphos shows no significant effect on bee brain acetylcholinesterase activity. These data suggest that acute application of coumaphos has only slight nonlethal effects upon the behavior of honey bees and should have little effect upon bee tasks that involve odor learning.

Acetone↗
PubMed1989

Effect of selection pressure on the cholinesterase of Boophilus microplus (Acari: Ixodidae) resistant to coumaphos.

The effect of selection pressure on the cholinesterase (AChE) activity of two strains of Boophilus microplus (Canestrini) resistant to coumaphos was monitored. Total AChE and protein was determined from three generations of resistant ticks and a susceptible strain. The effect of an AChE inhibitor, coroxon (the oxygen analog of coumaphos), was also determined. The resistance of the susceptible strain (Escondido) to coumaphos remained relatively unchanged throughout the study. The Tuxpan strain lost some of its resistance to coumaphos as the generations proceeded (AChE increased instead of decreased). The Tuxtla strain became more resistant to coumaphos as the generations proceeded (AChE increased).

Acetylcholinesterase↗
PubMed1982

Coumaphos: delayed neurotoxic effect following dermal administration in hens.

This study reports the differential neurotoxic effects of coumaphos [O,O-diethyl O-(3-chloro-4-methyl-7-coumarinyl) phosphorothioate] when applied orally or dermally in the adult hen. Dermal administration of single (50-500 mg/kg) or daily (100 mg/kg) doses resulted in delayed neurotoxicity in hens, similar to that caused by other delayed neurotoxic organophosphorus compounds. Coumaphos caused loss of weight and produced ataxia, which progressed to paralysis and death. Degeneration of axons and myelin in the spinal cord was the most consistent histopathologic alteration and was identical to that reported for other delayed neurotoxic organophosphorus esters. Only one hen showed peripheral nerve degeneration. Oral administration of a single 100 mg/kg dose or daily doses of 10 mg coumaphos caused severe acute toxicity and killed all treated hens 1-8 d. These hens did not develop delayed neurotoxicity. Some hens given a single oral 50-mg/kg dose or daily 5-mg/kg doses of coumaphos recovered from the initial cholinergic effect and developed clinical signs of delayed neurotoxicity. These hens, however, improved with time and did not show unequivocal nervous-tissue damage at termination.

Administration, Oral↗
PubMed2002

Persistence and degradation of coumaphos in model cattle dipping vats.

The stability of coumaphos [O,O-diethyl O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7 yl)phosphorothioatel was studied in model dipping vats under field conditions using 14C-labelled and unlabelled coumaphos, with or without additives. The stability of coumaphos in model vats increased significantly by maintaining a pH of 5 by addition of superphosphate. Copper sulphate amendment did not seem to have any additional effect on stability. Potasan was the major metabolite in addition to chlorferon and 4-methylumbelliferone. Coumaphos concentration was doubled in the sediment of vat treated with copper sulphate as compared to the control vat as a result of emulsion breakdown. Chlorferon was the only metabolite detected in the sediment of the former vat indicating inhibition of the anaerobic degradation.

Animals↗
PubMed2003

Efficacy of various concentrations of coumaphos to control adult, nymphal, and larval stages of an organophosphate-resistant strain of Boophilus microplus on infested cattle.

OBJECTIVE: 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. ANIMALS: 16 tick-naïve 200-kg female Hereford calves. PROCEDURE: Four groups of cattle (4 calves/group) were all infested with Boophilus ticks 3 times before treatment. Each group was treated with coumaphos as follows: group 1, at 0.165% active ingredient (AI); group 2, at 0.299% AI; group 3, at 0.566% AI; and group 4, not treated. Following treatment, ticks were collected for 21 days. Ticks collected 1 to 7, 8 to 14, and 15 to 21 days after treatment were considered adults, nymphs, and larvae, respectively, at time of treatment. RESULTS: Overall control at 0.165, 0.299, and 0.566% AI was 52.9, 75.8, and 89.7%, respectively. Control of adults ranged from 4.3% at 0.165% AI to 73.5% at 0.566% AI. Control of nymphs ranged from 60.6% at 0.165% AI to 97.3% at 0.566% AI. Control of larvae was > 98% at all coumaphos concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: All coumaphos concentrations failed to provide acceptable control for use in the US Eradication Program against OP-resistant ticks. Treatment was least effective against adults and most effective against larvae. Even at 0.566% AI (2 times higher than required by the US Eradication Program), ticks were not eradicated, placing the United States at risk from dispersing cattle harboring viable ticks to uninfested areas.

Animals↗
PubMed2001

Efficacy of flumethrin and coumaphos against the camel tick Hyalomma dromedarii L. (Acari: Ixodidae).

The efficacy of Flumethrin pour on and Coumaphos 50% WP was tested against different stages of Hyalomma dromedarii. With contact method, LC50 values for larvae and adults were 0.04, 0.03 ug/cm2 and 0.05, 1.06 ug/cm2 respectively. The LC50 for coumaphos against the larvae, adults and eggs using dipping method were 44, 63, and 62 ppm respectively. Flumethrin caused significant reduction in oviposition and hatchability in female ticks that survived sublethal concentrations, while sublethal doses of coumaphos had no effect on the reproductive potential of the tick. The results showed that flumethrin was 8 times more toxic than coumaphos.

Animals↗
PubMed1983

Determination of coumaphos and its oxygen analog in eggs and milk by using a multiresidue method with liquid chromatographic quantitation and capillary gas chromatographic/mass spectrometric confirmation.

A multiresidue method for carbamate insecticides was adapted for the determination of coumaphos and its oxygen analog in eggs and milk. Eggs were extracted with acetonitrile and milk was extracted with acetone. Co-extractives were removed using liquid partitioning and charcoal column procedures described in the carbamate method. Coumaphos and its oxygen analog were determined by using a high performance liquid chromatograph equipped with a fluorescence detector. Recovery studies were performed for the 2 compounds at levels of 0.01 and 0.10 ppm in eggs and 0.01 and 0.02 ppm in milk. Overall average recovery was 100% (range 95-109%). In a trial of the method by another laboratory, the recovery of coumaphos and its oxygen analog from milk averaged 87 and 96%, respectively. Data are presented on the capillary gas chromatographic/mass spectrometric confirmation of coumaphos residues.

Animals↗
PubMed1994

Evidence for the safety of coumaphos, diazinon and malathion residues in honey.

Residue levels of coumaphos, diazinon and malathion in honey were analysed in 177 samples of honey collected from different regions of Lugo in NW Spain in 1988-1990. One has to expect some of them as residues in honey, even if employed properly, for example coumaphos used against the parasitic mite Varroa jacobsoni. Honey samples were extracted with acetonitrile:water (2:1 v/v), partitioned with petroleum-ether, cleaned up with a manual Florisil column or Florisil Sep-Pack, evaporated to dryness, redissolved in an appropriate volume (1 mL) and then analyzed by GLC with a silica capillary column and nitrogen-phosphorus detector. Recoveries of coumaphos, diazinon and malathion varied between 80-97%. One hundred forty-eight samples contained no detectable residues, while 29 had residues of coumaphos and diazinon in ppb levels. These residues are minimal and when eating honey are harmless for the health of human beings.

Calibration↗
PubMed2005

Detoxification of the organophosphate nerve agent coumaphos using organophosphorus hydrolase immobilized on cellulose materials.

Neurotoxic organophosphates (OPs) are widely used as pesticides and for public health purposes, as well as being nerve gases. As a result of the widespread use of these compounds for agriculture, large volumes of wastewater are generated. Additionally, there are large stockpiles of the nerve gases soman, sarin and VX in the United States and elsewhere around the world. Organophosphorus hydrolase (OPH) is an enzyme that catalyzes the hydrolysis of OP nerve agents. To date, however, the use of this enzyme in detoxification processes has been rather limited due to the high cost of its purification and short catalytic half-life. This paper reports the development of a cost-effective method for the production and immobilization of OPH in a pilot application in an enzyme bioreactor column for detoxification of paraoxon and coumaphos in contaminated wastewaters. A fusion between OPH and a cellulose binding domain that binds selectively to cellulose was generated to allow one-step purification and immobilization of OPH on cheap and abundantly available cellulose immobilization matrices. When packed in a column bioreactor, the immobilized fusion enzyme was able to completely degrade coumaphos up to a concentration of 0.2 mM. However, stirring of OPH immobilized on cellulose materials resulted in complete OP degradation of 1.5 mM coumaphos. The bioreactor column degraded the compounds tested at high concentration, rapidly, and without loss of process productivity for about 2 months.

Aryldialkylphosphatase↗