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1.
BACKGROUND: Rodents are major pests in many agricultural systems, where they can cause significant economic losses and involve a sanitary risk. The application of anticoagulant rodenticides for rodent control has showed a decrease in effectiveness through time because of the development of resistant populations and the development of aversion behaviour. The goal of the present study was to test the susceptibility to bromadiolone and the existence of anticoagulant resistance in Mus musculus L. (house mouse) in Argentina. We conducted a feeding test with wild animals captured in poultry farms and a laboratory strain that were fed with bromadiolone bait. RESULTS: Three animals of the field experimental group survived the 21 days study period, while for laboratory animals mortality was 100%. Control field animals which were fed without anticoagulant showed 100% survival. CONCLUSION: We found evidence of the presence of anticoagulant resistant M. musculus L. in the study area. Feeding behaviour may have contributed to increasing the time of survival, and may be a mechanism that allows metabolic clearance of the bromadiolone. Under field conditions control with anticoagulants would be less effective because animals have alternative food. Copyright © 2009 Society of Chemical Industry  相似文献   

2.
为确定适于防治南疆农区鼠害的抗凝血类杀鼠剂, 在喀什地区疏勒县采用夹捕法、食饵法、粉迹法评估了杀鼠醚、溴敌隆、溴鼠灵的防治效果, 并采用灌胃法给药测试3种杀鼠剂对家鸡Gallus domestiaus和鸽子Columba livia的安全性。结果表明, 连续投放毒饵10 d后, 与溴敌隆防治区相比, 杀鼠醚防治区的阳性粉块和无毒小麦取食量的下降幅度均无显著差异, 但无毒小麦取食量下降的农户比例更高;且防治后褐家鼠比例更低, 防治期间毒饵消耗量更高。连续单独投放溴敌隆30 d的灭鼠效果可达90.9%, 但10 d溴敌隆与20 d溴鼠灵联合防治防效仅为65.9%。灌胃法测试表明, 对当地家禽类的毒性从低到高依次为杀鼠醚、溴敌隆和溴鼠灵。因此, 建议优选毒性较低的杀鼠醚或溴敌隆用于南疆农区鼠害防治。  相似文献   

3.
R. M. POCH 《EPPO Bulletin》1988,18(2):323-330
A series of toxicological, residue, secondary hazard, and environmental fate studies were completed with bromadiolone. The compound was eliminated rapidly after ingestion by Rattus norvegicus and Mus domesticus. In R. norvegicus, 75% of the bromadiolone was eliminated within 4 days. Dead rodents collected from field trials using bromadiolone had residue levels of 1.92 in R. rattus, 1.17 in M. domesticus, and 0.49 ppm in Spermophilus beecheyi. The LD50 for bromadiolone in beagle dogs was calculated at 8.1 mg kg-1 (10.7 for males and 6.3 mg kg-1 in females). The approximate LD50 in Canis latrans was 10 mg kg-1. Dietary LC50 determination compound in Putorius putorius furo was 9.8 ppm. Secondary hazard studies showed the rodenticide to have little potential to snakes and birds of prey if used properly. Field tests with grain and pelleted baits over 21 days demonstrated that the active ingredient degraded by 78 and 45%, respectively.  相似文献   

4.
BACKGROUND: Nucleotide polymorphisms in the VKORC1 gene can be linked to anticoagulant rodenticide resistance in Norway rats (Rattus norvegicus Berkenhout). This provides a fitness advantage to rats exposed to anticoagulant actives, but may also cause fitness costs. The vitamin K requirement and reproductive parameters of bromadiolone‐resistant rats (Westphalian resistant strain; VKOR variant Tyr139Cys) and bromadiolone‐susceptible Norway rats were compared. RESULTS: At vitamin K deficiency, blood clotting times increased in all homozygous resistant males within 8 days and in 80% of homozygous resistant females within 15 days. There was little effect on blood clotting in heterozygous males and no effect in heterozygous females and VKOR wild‐type individuals. Litter size was about 20% higher in sensitive pairs compared with resistant pairs. Testes growth, male gonad weight, sperm motility and testis cell concentration were unaffected by the mutation. CONCLUSIONS: The VKOR variant Tyr139Cys causes considerable physiological cost in Norway rats in terms of vitamin K requirement and reproduction. This may affect the distribution and spread of resistant individuals in the wild. Decreased litter size of resistant parents seems to be due to lowered female reproductive performance, as there was no significant effect of the mutation on any aspects of male reproduction considered, but this requires further study. Copyright © 2011 Society of Chemical Industry  相似文献   

5.
Resistance to the first successful anticoagulant rodenticide, warfarin, was detected in the Norway rat (Rattus norvegicus Berk.) in 1958, and it has since expanded to cover other commensal rodent species (R. rattus L., Mus musculus L.) and the majority of later-developed anticoagulant compounds. The purpose of this paper is to give an up-to-date picture of the current distribution of anticoagulant resistance in Europe, as revealed by the questionnaire dispatched by EPPO (European and Mediterranean Plant Protection Organization) to its member countries in 1992. Replies were received from 13 countries (43% of EPPO members), and it was found that broad-spectrum resistance occurred in practically all those countries that reported testing activity. A likely conclusion based on this finding is that true distribution of resistance is certainly more extensive than documented by the questionnaire replies. Another conclusion drawn by the EPPO Rodent Control Panel was that the existing resistance detection protocols were no longer adequate to cover the whole array of existing anticoagulant rodenticides. Consequently, a new guideline including novel methods particularly for detecting resistance to single-dose anticoagulant compounds was urgently needed. This guideline is currently under review.  相似文献   

6.
BACKGROUND: Emerging resistance to anticoagulant rodenticides may significantly impair house mouse (Mus musculus L.) control. As in humans and rats, sequence variants in the gene vitamin K epoxide reductase complex subunit 1 (VKORC1) of house mice are strongly implicated in the responses of mice to anticoagulants. This study gives a first overview of the distribution and frequency of such potentially resistance‐conferring sequence variants in house mice, based on tissue samples from 30 populations in Germany, Switzerland and the Azores. RESULTS: Except for one population from south Germany, sequence variants were found in individuals from all locations sampled (29 out of 30 sites surveyed), with less than 10% of the individuals matching the wild‐type genotype. The most frequent and widespread amino acid substitutions were Leu128Ser, Tyr139Cys and a group of linked sequence changes (Arg12Trp/Ala26Ser/Ala48Thr/Arg61Leu). Where these substitutions occurred as the sole variant, the proportion of homozygous individuals was 72–83%. CONCLUSIONS: An evaluation of published data revealed that the three most frequently found sequence variants are associated with a substantial loss of rodenticide efficacy of first‐generation anticoagulants (e.g. warfarin, coumatetralyl), as well as the second‐generation compound bromadiolone and most probably also difenacoum. Knowledge of the distribution and frequency of resistance‐conferring sequence variants will stimulate their further functional characterisation and facilitate the choice of effective active substances for house mouse control. Copyright © 2011 Society of Chemical Industry  相似文献   

7.
Widespread anticoagulant resistance was discovered in populations of the brown rat (Rattus norvegicus Berk.) in an area of roughly 8000 km2 in north-west Germany. Resistance testing was performed by feeding tests and/or by measuring blood clotting response after intraperitoneal injection of a sublethal testing solution. A hierarchical resistance system was found with warfarin resistance at the base followed by bromadiolone/coumatetralyl resistance to difenacoum resistance at the top. Warfarin resistance was spread over the whole area with reduced incidence towards the edges. Difenacoum resistance represented the highest level found so far and was restricted to the inner zone of the resistance area where it occurred with a frequency of 6% of all individuals tested. Breeding experiments with bromadiolone-resistant rats showed that expression of the bromadiolone resistance gene differed in the two sexes, suggesting additional sex-linked modifying effects to the resistance gene. Control strategy within the resistance area with respect to prevention of further selection for resistance is discussed.  相似文献   

8.
Widespread use of warfarin, and other multiple-dose anticoagulants, selected populations of warfarin-resistant rodents in the UK and in other countries. The effectiveness of rodent control was dramatically reduced when the resistant animals formed a large proportion of a population. The second-generation anticoagulants were developed to overcome these practical control problems with warfarin and were considered to be effective rodenticides against warfarin-resistant populations. In the UK, however, difenacoum showed reduced efficacy for controlling an established warfarin-resistant Rattus norvegicus population covering a substantial area of farmland in southern England. Continued use of difenacoum selected for difenacoum-resistant animals, so that the rodenticide is now ineffective for controlling rats in three counties. Brodifacoum was subsequently used to control some infestations and there is evidence that these treatments selected for animals with an increased level of resistance to brodifacoum. Anticoagulant resistance in Mus domesticus is less of a practical problem because of the availability of non-anticoagulant rodenticides for the control of this species. There is evidence, however, of bromadiolone resistance in M. domesticus trapped on farms in the UK. Recent investigations of the mechanism of anticoagulant resistance in R. norvegicus have indicated that vitamin K3 (menadione) is an antidote to anticoagulants in resistant animals. This form of the vitamin is included as a dietary supplement in poultry and pig food and would aid the survival, and therefore increase the selection, of resistant animals when anticoagulants are used exclusively.  相似文献   

9.
To examine the role of xenobiotic relevant genes in bromadiolone resistance in wild Norway rats (Rattus norvegicus) we compared the constitutive liver gene expression and expression upon bromadiolone administration in bromadiolone resistant and anticoagulant susceptible female rats using a LNA microarray and quantitative PCR. Resistant rats showed significantly higher constitutive expression of the cytochrome P450 genes Cyp2c13 and Cyp3a2 and lower expression of Cyp2e1 and Gpox1 compared to the susceptible rats. The Cyp1a2, Cyp2c13, Cyp2e1, Cyp3a2 and Cyp3a3 genes were significantly higher expressed in resistant than susceptible rats upon bromadiolone exposure. To establish how bromadiolone affected xenobiotic gene expression in the two strains we compared bromadiolone expression profiles to saline profiles of both strains. Bromadiolone mediated significant up-regulation of Cyp2e1 and Cyp3a3 expression in the resistant rats whereas the rodenticide conferred down-regulation of Cyp2e1, Cyp3a3 and Gpox1 and induction of Cyp2c12 expression in susceptible rats. Cyp2c13 and Cyp3a2 expression were markedly suppressed in both strains upon treatment. This suggests that xenobiotic relevant enzymes play a role in bromadiolone resistance in the Norway rat. A high constitutive expression of Cyp2c13 and Cyp3a2 and induction of Cyp1a2, Cyp2e1 and Cyp3a3 expression during bromadiolone exposure may increase the resistance to bromadiolone presumably by facilitating increased detoxification and decreased liver injury.  相似文献   

10.
Abstract

Field trials were conducted to control rodent pests of wheat crop by improving bait acceptability through taste enhancers (additives). Egg shell, egg yolk, yeast, minced meat, sheep blood and chicken blood were mixed 2% by weight individually in a bait base of broken rice and wheat flour. Brodifacoum and bromadiolone bait with egg shell additive ranked first, and egg yolk second, in preference over other additive poison baits and poison bait without additive. Poison baiting yielded 93.3% and 86.7% reduction in rodent population with brodifacoum and bromadiolone (0.005% each), respectively. Three baitings, at tillering, flowering and maturity stage of the crop, gave 91.0% tiller damage reduction with brodifacoum and 86.0% with bromadiolone as compared to control (untreated). It is concluded that three poison baitings containing egg shell additive should be initiated at tillering stage followed by flowering and maturity of the wheat crop for increased yield.  相似文献   

11.
BACKGROUND: Anticoagulant resistance in Norway rats, Rattus norvegicus (Berk.), has been suggested to be conferred by mutations in the VKORC1 gene, encoding the target protein of anticoagulant rodenticides. Other factors, e.g. pharmacokinetics, may also contribute to resistance, however. To examine the involvement of pharmacokinetics in bromadiolone resistance in male and female rats, liver expression profiles of seven cytochrome P450 genes from a Danish bromadiolone-resistant rat strain (with an Y139C-VKORC1 mutation) were compared with profiles from an anticoagulant-susceptible strain. RESULTS: In the presence of bromadiolone, the Cyp2e1, Cyp2c13, Cyp3a2 and Cyp3a3 genes were significantly overexpressed, while Cyp2c12 expression was suppressed in resistant female rats compared with susceptible females. Relative to susceptible males, resistant males showed significant overexpression of the Cyp2a1, Cyp2e1, Cyp3a2 and Cyp3a3 genes. On exposure to bromadiolone, females had higher Cyp2e1 expression than males, which possibly explains why female rats are generally more tolerant to anticoagulants than male rats. CONCLUSION: Results suggest that bromadiolone resistance in a Danish strain of Norway rats involves enhanced anticoagulant metabolism catalysed by cytochrome P450-2e1, -3a2 and -3a3. This pharmacokinetically based bromadiolone resistance is to some extent sex differentiated, as female resistance furthermore seems to involve overexpression of cytochrome P450-2c13 and suppression of P450-2c12, whereas male resistance appears to involve P450-2a1 overexpression.  相似文献   

12.
The baseline susceptibility of the Indian field mouse, Mus booduga was established for warfarin, bromadiolone and brodifacoum by means of nochoice feeding tests. The mice were found to be more susceptible to the second generation anticoagulants bromadiolone (0.005 g kg?1) and brodifacoum (0.002 g kg?1) than warfarin (0-25 g kg?1). They required 8–10 days feeding on warfarin (0.25 g kg?1) diet for complete mortality. A feeding period of 8 days corresponding to 99% mortality was suggested as a checking test for registering future warfarin resistance in suspect samples of M. booduga.  相似文献   

13.
The toxicity of the anticoagulant brodifacoum to the field rodent species Microtus guentheri (Danford & Alston) and Meriones tristrami Thomas was tested in the laboratory. Brodifacoum 0.05 g kg?1 whole-wheat bait was offered to the animals without additional food. The LD50 calculated for M. guentheri was 2.28 mg kg?1 body weight. Brodifacoum was found to be more toxic to M. tristrami; the LD50 was c. 0.8–0.9 mg kg?1 body weight. The toxicity data served to plan the doses of bait to be broadcast in the field.  相似文献   

14.
K. NAHAS 《EPPO Bulletin》1988,18(2):317-322
L'efficacité comparée de la bromadiolone et du coumafène contre Rattus norvegicus (souche sensible au coumafène) a étéétudiée en laboratoire avec différentes concentrations en principes actifs et pour différentes durées d'exposition aux appâts. La bromadiolone s'est révélée beaucoup plus active (100% de mortalité en 1 j à 50 ppm) que le coumafène (50% de mortalité en 3 j à 250 ppm). Pour expliquer cette différence d'efficacité, les cinétiques plasmatiques et hépatiques des deux rodenticides ont été comparées chez la même espèce. A une dose équimolaire de 5,69 μmole kg-1 (correspondant respectivement pour le coumafène et pour la bromadiolone à une seule ingestion d'appâts de 20 et 50 ppm), la bromadiolone a eu une demi-vie plasmatique de l'ordre de 57,5 h contre 8 pour le coumafène. Le volume de distribution de la bromadiolone était 188 fois plus élevé que celui du coumafène. Le rapport de la concentration hépatique sur la concentration plasmatique a varié en fonction du temps de 14 à 46 pour la bromadiolone et de 0,1 à 0,49 pour le coumafène. Les données cinétiques obtenues montrent que la bromadiolone possède un tropisme et un captage hépatiques importants, qui assurent un blocage prolongé du cycle de la vitamine K et donc une efficacité accrue.  相似文献   

15.
Resistance to anticoagulant rodenticides in brown rats (Rattus norvegicus Berk.) is associated with pleiotropic effects, notably with an increased dietary vitamin K requirement. Owing to this disadvantage, resistance is believed to be selected against if anticoagulant selection is absent. In small experimental populations of wild brown rats, an investigation was carried out to establish whether tolerance to anticoagulant exposure changed over a period of 2 years. In the same populations, DNA microsatellite markers were used to infer parentage, and this made it possible to estimate reproductive success of sensitive and resistant rats and estimate effective population size, Ne. Even though there was evidence for a selection against resistant rats with high vitamin K requirement, anticoagulant tolerance was not seen to be significantly influenced in the absence of bromadiolone selection. As the population size under investigation was small, random genetic drift may have played a role in this. In the presence of bromadiolone selection, however, the tolerance was significantly increased, suggesting that continuous selection will increase the proportion of highly resistant rats in the population. It was found that, for both males and females, surprisingly few individuals contributed to the next generation with numerous offspring, and most breeders contributed with none or a single offspring. The expected higher reproductive success and consequent increase in proportional numbers of sensitive rats in the absence of anticoagulant selection could not be observed. Among the resistant rats, moderately resistant females were found to be better breeders than highly resistant breeders, but for resistant males the reverse was true. This could be explained by the fact that the increased vitamin K requirement results in sex differential selection; in highly resistant males the selection presumably takes place at the immature stage, whereas in females the vitamin K requirement becomes crucial at the reproductive stage, as vitamin K is not only essential for the blood clotting process but also for bone formation.  相似文献   

16.
BACKGROUND: The tyrosine to cysteine amino acid substitution at location 139 of the vkorc1 protein (i.e. tyrosine139cysteine or Y139C) is the most widespread anticoagulant resistance mutation in Norway rats (Rattus norvegicus Berk.) in Europe. Field trials were conducted to determine the incidence of the Y139C mutation at two rat‐infested farms in Westphalia, Germany, and to estimate the practical efficacy against them of applications, using a pulsed baiting treatment regime, of a proprietary bait (Klerat?) containing 0.005% brodifacoum. RESULTS: DNA analysis for the Y139C mutation showed that resistant rats were prevalent at the two farms, with an incidence of 80.0 and 78.6% respectively. Applications of brodifacoum bait achieved results of 99.2 and 100.0% control at the two farms, when measured by census baiting, although the treatment was somewhat prolonged at one site, possibly owing to the abundance of attractive alternative food. CONCLUSION: The study showed that 0.005% brodifacoum bait is fully effective against Norway rats possessing the Y139C mutation at the Münsterland focus and is likely to be so elsewhere in Europe where this mutation is found. The pulsed baiting regime reduced to relatively low levels the quantity of bait required to control these two substantial resistant Norway rat infestations. Previous studies had shown much larger quantities of bromadiolone and difenacoum baits used in largely ineffective treatments against Y139C resistant rats in the Münsterland. These results should be considered when making decisions about the use of anticoagulants against resistant Norway rats and their potential environmental impacts. Copyright © 2012 Society of Chemical Industry  相似文献   

17.
Flocoumafen is a new, highly potent anticoagulant rodenticide from Shell Research. It is effective against all the economically important species tested to date, including those with warfarin-resistant strains. This paper is concerned with its performance against two important commensal rodent species, Mus domesticus and Rattus norvegicus. In laboratory studies these two pest species may absorb a lethal dose of flocoumafen by taking a 0.005% (50 ppm) bait as part of their food intake on only one occasion. This single-feed potency of flocoumafen, combined with its good intrinsic palatability, makes it ideal for use in pulse baiting. Marketed under the Shell trade mark Storm, the principal bait formulation selected for commercialization is the wax-bound block. Recent advances in formulation development include increased resistance to attack by insects and fungi and the incorporation of a bitter taste which acts as a deterrent for humans without influencing the palatability of the bait to rodents. Flocoumafen's outstanding potency has been confirmed in a wide range of field trials. In the UK alone, almost 70 pen and field trials have been successfully completed with a mean estimated control in excess of 95%.  相似文献   

18.
Abstract

Mus musculus, Rattus rattus and Rattus norvegicus are pests in poultry farms, causing economic losses and transmitting diseases. Control is commonly conducted through anticoagulant rodenticides, but this control is not effective through time. We aimed to assess the effect of rodent exclosure on long-term success of rodent control in poultry farms of the pampean region, Argentina, and to evaluate indirect estimators of rodent abundance. In both exclosure and non-exclosure sheds rodent abundance decreased significantly after eradication but mice populations showed a recovery, suggesting that the eradication was not complete. Rats did not recover, but the low abundance found at the beginning of the experiment does not allow an accurate conclusion.  相似文献   

19.
耿马县黄胸鼠发生规律与防控研究   总被引：1，自引：0，他引：1  
1992-2008年,在云南省耿马县城区海拔1 100 m地区农田设置系统监测点,研究害鼠种类及发生消长规律。结果表明,农田害鼠以黄胸鼠为绝对优势种群,占17年所捕获害鼠总数的83%,近4年所捕害鼠全为黄胸鼠。年内捕获率和繁殖力出现双峰,与田间为害高峰相吻合。雌雄性比为1∶1.8,雄性多于雌性。以成体组捕获率最高,占总捕鼠数的50%;幼体组和亚成体组次之,分别占21%和20%。根据年内消长规律,确定化学统一灭鼠时间为4月中旬和10月底的干季。宜选用敌鼠、溴敌隆、氯鼠酮、氟鼠灵等,以稻谷作饵料为好。  相似文献   

20.
Adult, 20-week-old, rats from a Danish bromadiolone-resistant strain of rats (Rattus norvegicus) over-express the cytochrome P450 genes Cyp2e1, Cyp3a2 and Cyp3a3 upon bromadiolone exposure. Furthermore, adult female rats of this strain over-express the Cyp2c13 gene and suppress Cyp2c12, while males over-express the Cyp2a1 gene. The altered gene expression has been suggested to be involved in the bromadiolone resistance by facilitating enhanced anticoagulant metabolism. To investigate the gene expression of these cytochrome P450 genes in rats of different developmental stages we compared expression profiles from 8-, 12- and 20-week-old resistant rats of the Danish strain to profiles of anticoagulant-susceptible rats of same ages. The three age-groups were selected to represent a group of pre-pubertal, pubertal and adult rats. We found expression profiles of the pre-pubertal and pubertal resistant rats to concur with profiles of the adults suggesting that cytochrome P450 enzymes are involved in the Danish bromadiolone resistance regardless of developmental stage. We also investigated the relative importance of the six cytochrome P450s in the different development stages of the resistant rats. The P450-3a2 and -3a3 isoforms were proposed to be of higher importance in adult male resistance than in pre-pubertal resistance. In contrast, the P450-2c13 and -3a2 isoforms were proposed to be more important in sexual immature female resistance, while the P450-2e1 and -3a3 isoforms were suggested to play a more significant role in adult female resistance.  相似文献   

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