Coccidiosis is a gastrointestinal disease caused by parasites of the genus Eimeria. To produce the ecological niche model for the geographic distribution of Eimeria species, the maximum entropy algorithm (MaxEnt) was ...Coccidiosis is a gastrointestinal disease caused by parasites of the genus Eimeria. To produce the ecological niche model for the geographic distribution of Eimeria species, the maximum entropy algorithm (MaxEnt) was used and 19 bioclimatic variables with a spatial resolution of 30 arc-seconds (approximately 1 km2) were downloaded from the World Climate Database. These were reduced to BIO2, BIO3, BIO4, BIO7 and BIO15 for each species after examining cross-correlations among them to account multicollinearity. A jackknife analysis was included to assess the contribution of five bioclimatic variables and the fit of the model was evaluated with the area under receiver operating characteristic curve (AUC). Under a current climate scenario, the jackknife evaluation of the MaxEnt model showed that BIO4 (temperature seasonality) made the greatest contribution to the distribution model for 22 Eimeria species;whereas BIO7 (temperature annual range) was the most important factor that contributes to the distribution model of 10 species. The habitat suitability model based on the maximum entropy theory was supported by AUC values higher than 0.9 and predicted that the suitable habitats for different species of Eimeria are present in southern, eastern and western areas of Mexico. Our study may support future studies exploring factors that constrain the distribution of Eimeria as well as strategies aimed at reducing the disease prevalence.展开更多
Fleas that infest pets are considered important parasites of both animals and humans. These insects cause irritation and can also transmit zoonotic diseases. Research has led to a rapid expansion in the development of...Fleas that infest pets are considered important parasites of both animals and humans. These insects cause irritation and can also transmit zoonotic diseases. Research has led to a rapid expansion in the development of flea control products. In the face of a market that offers dozens of commercial ectoparasiticides for dogs and cats, pet owners and veterinarians must be provided with evidence to support their decision to select a product to control fleas. To compare the efficacy of three commercially available products against companion animal fleas, a trial was conducted on naturally-infested dogs in order to validate their pulicidal activity. Thirty-two flea-infested dogs with fleas were divided into 4 groups (n = 8) for each treatment. Group 1 received one pipette of permethrin as a spot-on dose of 650 mg/ml. The second group received 9.7% fipronil as a spot-on formulation. Group 3 was treated with a spot-on formulation of permethrin 7.40% plus piperonyl butoxide at 7.40%. Group 4 remained as the untreated control. Fleas of all experimental dogs were examined and counted on days 0, 3, 7, 14, 21 and 28 to determine the percentage of flea reduction. Results showed a 100% efficacy for all tested products. Identified species were: Ctenocephalides felis (75.7%), Ctenocephalides canis (15.9%) and Pulex irritans (9.5%). Based on these results, it was concluded that the three anti-flea products evaluated under the conditions of this study, produced an excellent efficacy as from the third day after treatment.展开更多
Acaricide resistance is a major problem that hinders the control of the cattle tick Rhipicephalus (Boophilus) microplus in Mexico. Permethrin (P), cypermethrin (C) and zeta-cypermethrin (Z) have been used to control R...Acaricide resistance is a major problem that hinders the control of the cattle tick Rhipicephalus (Boophilus) microplus in Mexico. Permethrin (P), cypermethrin (C) and zeta-cypermethrin (Z) have been used to control R. (B.) microplus, and tick populations have developed resistance to these acaricides. The aim of the present study was to evaluate the effectiveness of a mixture containing P, C, or Z mixed with plant extracts through in vitro laboratory bioassays, using susceptible and triple resistant (San Alfonso) R. microplus strains. Untreated controls received only water. Results of laboratory bioassays using larval packet tests revealed an efficacy of 100% (P), 100% (Z), and 98.03% (C) using susceptible larvae, and an efficacy of 88.67% (P), 91.51% (C), and 99.27% (Z) on triple-resistant larvae. Egg laying, larvae hatching and efficacy was assessed using ticks collected from treated and untreated animals. Product Z produced a 92.04% efficacy on engorged ticks collected from experimentally-infested cattle, whereas C and P exerted 80.66% and 20.04% efficacy, respectively. Engorged females collected exclusively from control animals were challenged in vitro with the experimental products, and efficacy was as follows: 91.37% (Z), 85.95% (C), and 13.58% (P). Adding plant extracts to a pyrethroid formulation led to dramatic increases of percent reduction of both susceptible and resistant immature ticks in contrast to untreated larvae and susceptible adults. Results from this study may lead to suggesting the adoption of an acari-cide-botanical mixture strategy for tick control worldwide.展开更多
文摘Coccidiosis is a gastrointestinal disease caused by parasites of the genus Eimeria. To produce the ecological niche model for the geographic distribution of Eimeria species, the maximum entropy algorithm (MaxEnt) was used and 19 bioclimatic variables with a spatial resolution of 30 arc-seconds (approximately 1 km2) were downloaded from the World Climate Database. These were reduced to BIO2, BIO3, BIO4, BIO7 and BIO15 for each species after examining cross-correlations among them to account multicollinearity. A jackknife analysis was included to assess the contribution of five bioclimatic variables and the fit of the model was evaluated with the area under receiver operating characteristic curve (AUC). Under a current climate scenario, the jackknife evaluation of the MaxEnt model showed that BIO4 (temperature seasonality) made the greatest contribution to the distribution model for 22 Eimeria species;whereas BIO7 (temperature annual range) was the most important factor that contributes to the distribution model of 10 species. The habitat suitability model based on the maximum entropy theory was supported by AUC values higher than 0.9 and predicted that the suitable habitats for different species of Eimeria are present in southern, eastern and western areas of Mexico. Our study may support future studies exploring factors that constrain the distribution of Eimeria as well as strategies aimed at reducing the disease prevalence.
文摘Fleas that infest pets are considered important parasites of both animals and humans. These insects cause irritation and can also transmit zoonotic diseases. Research has led to a rapid expansion in the development of flea control products. In the face of a market that offers dozens of commercial ectoparasiticides for dogs and cats, pet owners and veterinarians must be provided with evidence to support their decision to select a product to control fleas. To compare the efficacy of three commercially available products against companion animal fleas, a trial was conducted on naturally-infested dogs in order to validate their pulicidal activity. Thirty-two flea-infested dogs with fleas were divided into 4 groups (n = 8) for each treatment. Group 1 received one pipette of permethrin as a spot-on dose of 650 mg/ml. The second group received 9.7% fipronil as a spot-on formulation. Group 3 was treated with a spot-on formulation of permethrin 7.40% plus piperonyl butoxide at 7.40%. Group 4 remained as the untreated control. Fleas of all experimental dogs were examined and counted on days 0, 3, 7, 14, 21 and 28 to determine the percentage of flea reduction. Results showed a 100% efficacy for all tested products. Identified species were: Ctenocephalides felis (75.7%), Ctenocephalides canis (15.9%) and Pulex irritans (9.5%). Based on these results, it was concluded that the three anti-flea products evaluated under the conditions of this study, produced an excellent efficacy as from the third day after treatment.
文摘Acaricide resistance is a major problem that hinders the control of the cattle tick Rhipicephalus (Boophilus) microplus in Mexico. Permethrin (P), cypermethrin (C) and zeta-cypermethrin (Z) have been used to control R. (B.) microplus, and tick populations have developed resistance to these acaricides. The aim of the present study was to evaluate the effectiveness of a mixture containing P, C, or Z mixed with plant extracts through in vitro laboratory bioassays, using susceptible and triple resistant (San Alfonso) R. microplus strains. Untreated controls received only water. Results of laboratory bioassays using larval packet tests revealed an efficacy of 100% (P), 100% (Z), and 98.03% (C) using susceptible larvae, and an efficacy of 88.67% (P), 91.51% (C), and 99.27% (Z) on triple-resistant larvae. Egg laying, larvae hatching and efficacy was assessed using ticks collected from treated and untreated animals. Product Z produced a 92.04% efficacy on engorged ticks collected from experimentally-infested cattle, whereas C and P exerted 80.66% and 20.04% efficacy, respectively. Engorged females collected exclusively from control animals were challenged in vitro with the experimental products, and efficacy was as follows: 91.37% (Z), 85.95% (C), and 13.58% (P). Adding plant extracts to a pyrethroid formulation led to dramatic increases of percent reduction of both susceptible and resistant immature ticks in contrast to untreated larvae and susceptible adults. Results from this study may lead to suggesting the adoption of an acari-cide-botanical mixture strategy for tick control worldwide.
