Malaria incidence in urban areas has generally been low compared to rural areas but recent data indicate that urban malaria remains a public health problem. It is therefore important to understand the factors that pro...Malaria incidence in urban areas has generally been low compared to rural areas but recent data indicate that urban malaria remains a public health problem. It is therefore important to understand the factors that promote urban malaria to help formulate future vector control strategies. This study compared Anopheles gambiae s.l. (A. gambiae s.l.) species composition, distribution and insecticide resistance mechanisms between vegetable and non-vegetable growing areas in Accra Metropolis. Four sites were selected within the city of Accra which comprised of two vegetable-growing and two non-vegetable growing areas. WHO susceptibility tests were carried out on adults A. gambiae s.l. reared from larvae collected from the sites. Five insecticides were tested and the A. gambiae complex, resistance genotypes and enzyme activities of each population were characterized. All A. gambiae s.l. populations tested were resistant to all the insecticides, but relatively lower mortalities were observed in the vegetable growing areas. The mortality against 0.05% deltamethrin was 2.6% (Opeibea) and 12.5% (Korle-Bu) for the vegetable growing areas and 36.2% (Achimota) and 38.9% (Mataheko) in the non-vegetable growing areas. Anopheles gambiae s.s. (95% of Opeibea population) and Anopheles coluzzii, (98% of Korle-Bu population) were the dominant species in the vegetable growing areas. The voltage-gated sodium channel (Vgsc-1014F) frequencies of all the populations were similar but the acetylcholinesterase (ace-1) frequencies were significantly lower (p A. gambiae s.l. from Opeibea than from the other areas. The contribution of urban agriculture in the development of insecticide resistance needs to be considered in the formulation of future vector control strategies alongside other domestic usages.展开更多
Objective:To determine fauna and some ecological aspects of Anopheles mosquitoes in northeast of Iran.Methods:In this descriptive study,3 villages in Kalaleh County were selected in different geographical zones.Anophe...Objective:To determine fauna and some ecological aspects of Anopheles mosquitoes in northeast of Iran.Methods:In this descriptive study,3 villages in Kalaleh County were selected in different geographical zones.Anopheles mosquitoes were collected biweekly from May to October using standard dipping method for larvae,and hand catch,total catch,artificial pit shelter as well as night-biting collections on human and animal baits for adults.Results:Totally 399 larvae and 2 602 adults of Anopheles mosquitoes were collected and identified as 2 species:Anopheles superpictus s.l.(An.superpictus s.l.) and Anopheles maculipennis s.l.The dominant species was An.superpictus s.l.(92.1%).Activity of these mosquitoes found to be started from middle of May and extended till September with two peaks of activity in July and August.Conclusions:An.superpictus s.l.as one of the main malaria vectors in Iran as well as some other parts of the world is the dominant species in the study area.This species has high potential for transmission and possibility of establishing a transmission cycle with low abundance.Other species,Anopheles maculipennis s.l.also has introduced as a malaria vector in northern parts of Iran.As this Anopheles is a complex species,genetic studies are recommended to determine the members of this complex in the study area.展开更多
Objective:To evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s.Methods:Larvicidal effects of each compound were evaluated in both labora...Objective:To evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s.Methods:Larvicidal effects of each compound were evaluated in both laboratory and semi-field trials.Stock solution was prepared and serial dilutions were made in six concentrations for each compound.A total of 20 larvae were exposed to larvicides for each replicate and monitored at intervals of 12,24,48 and 72 h.Larvae monitoring was done on basis of dead and live larvae in all intervals.Results:All assayed compounds were larvicides and presented varying degrees of larval toxicity,with LC50 values ranging from 1.28 to 1 938.92 mg/L depending on the treatment time(12,24,48 or 72 h).(-)-Perillyl alcohol presented the strongest larvicidal activity towards Anopheles gambiae larvae,with LC_(50) values of 73.60,18.36,1.72 and1.28 mg/L after 12,24,48 and 72 h of exposure,respectively.The next strongest were(-)-isopulegol(LC_(50)= 135.10,49.39,34.39 and 20.22 mg/L) and(-)-carvone epoxide(LC_(50)= 168.86,124.74,80.84 and 23.46 mg/L).After 12,24 and 48 h of treatment,hydroxydihydrocarvone was the least toxic compound,with LC_(50) values of 1 938.92,1 172.18 and 401.03 mg/L,respectively.Conclusions:The data obtained in this study suggest that all evaluated monoterpenes,especially(-)-perillyl alcohol,have remarkable larvicidal effects and may be considered as potential sources for the development of suitable natural larvicides for mosquito management programs.Further small-scale field trials should be conducted.展开更多
The epsilon class glutathione-S-transferase of Anopheles gambiae, agGSTe2, is capable of metabolizing DDT. A molecular docking analysis of DDT with agGSTe2 support an E2 elimination mechanism wherein the glutathione s...The epsilon class glutathione-S-transferase of Anopheles gambiae, agGSTe2, is capable of metabolizing DDT. A molecular docking analysis of DDT with agGSTe2 support an E2 elimination mechanism wherein the glutathione sulfur serves as the base to convert DDT to DDE.展开更多
Objective:To explore ovariole basal body granulations and follicular dilatations for determining physiological age inAnopheles gambiaes.s.(An.gambiaes.s.).Methods:Mosquitoes were collected by using window trap catch a...Objective:To explore ovariole basal body granulations and follicular dilatations for determining physiological age inAnopheles gambiaes.s.(An.gambiaes.s.).Methods:Mosquitoes were collected by using window trap catch and identified morphologically.For the first lot ofmosquitoes,they were dissected,and ovary was left in distilled water for reading ovarian tracheoles and the second was cut and transferred to another blade in a physiological liquid for verification of ovariole basal body granulations.The same approach was followed with the second lot of mosquitoes where follicular dilatations were found after classic dilaceration of ovaries were transferred into physiological liquid.The other body parts of mosquitoes were used to identify the species of theAn.gambiaes.s.complex by PCR.Results:Among the 123An.gambiae s.s.of the first lot,the method of Detinova determined the age of 89 mosquitoes versus 114 for the observation of granulations(P>0.05).Among the 112An.gambiae s.s.of the second lot,the method of Detinova determined the age of 84 mosquitoes versus 93 for the observation of follicular dilatations(P>0.05).Unlike the method of Detinova,observation of follicular dilatations and basal body granulations of ovarioles were possible beyond the stage II Christophers.Conclusions:Overall,the observation of follicular dilatations and ovariole basal body granulations are reliable for the determination of the physiological age inAn.gambiaes.s.Furthermore,these two methods can be used beyond the stage II.展开更多
文摘Malaria incidence in urban areas has generally been low compared to rural areas but recent data indicate that urban malaria remains a public health problem. It is therefore important to understand the factors that promote urban malaria to help formulate future vector control strategies. This study compared Anopheles gambiae s.l. (A. gambiae s.l.) species composition, distribution and insecticide resistance mechanisms between vegetable and non-vegetable growing areas in Accra Metropolis. Four sites were selected within the city of Accra which comprised of two vegetable-growing and two non-vegetable growing areas. WHO susceptibility tests were carried out on adults A. gambiae s.l. reared from larvae collected from the sites. Five insecticides were tested and the A. gambiae complex, resistance genotypes and enzyme activities of each population were characterized. All A. gambiae s.l. populations tested were resistant to all the insecticides, but relatively lower mortalities were observed in the vegetable growing areas. The mortality against 0.05% deltamethrin was 2.6% (Opeibea) and 12.5% (Korle-Bu) for the vegetable growing areas and 36.2% (Achimota) and 38.9% (Mataheko) in the non-vegetable growing areas. Anopheles gambiae s.s. (95% of Opeibea population) and Anopheles coluzzii, (98% of Korle-Bu population) were the dominant species in the vegetable growing areas. The voltage-gated sodium channel (Vgsc-1014F) frequencies of all the populations were similar but the acetylcholinesterase (ace-1) frequencies were significantly lower (p A. gambiae s.l. from Opeibea than from the other areas. The contribution of urban agriculture in the development of insecticide resistance needs to be considered in the formulation of future vector control strategies alongside other domestic usages.
基金Supported by the Research deputy of Golestan University of Medical Sciences(No.:35/678)
文摘Objective:To determine fauna and some ecological aspects of Anopheles mosquitoes in northeast of Iran.Methods:In this descriptive study,3 villages in Kalaleh County were selected in different geographical zones.Anopheles mosquitoes were collected biweekly from May to October using standard dipping method for larvae,and hand catch,total catch,artificial pit shelter as well as night-biting collections on human and animal baits for adults.Results:Totally 399 larvae and 2 602 adults of Anopheles mosquitoes were collected and identified as 2 species:Anopheles superpictus s.l.(An.superpictus s.l.) and Anopheles maculipennis s.l.The dominant species was An.superpictus s.l.(92.1%).Activity of these mosquitoes found to be started from middle of May and extended till September with two peaks of activity in July and August.Conclusions:An.superpictus s.l.as one of the main malaria vectors in Iran as well as some other parts of the world is the dominant species in the study area.This species has high potential for transmission and possibility of establishing a transmission cycle with low abundance.Other species,Anopheles maculipennis s.l.also has introduced as a malaria vector in northern parts of Iran.As this Anopheles is a complex species,genetic studies are recommended to determine the members of this complex in the study area.
基金Supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico,Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior,and Fundacao de Apoio a Pesquisa e Inovacao Tecnol'ogica do Estado de Sergipe(Grant#475520/2012-2)
文摘Objective:To evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s.Methods:Larvicidal effects of each compound were evaluated in both laboratory and semi-field trials.Stock solution was prepared and serial dilutions were made in six concentrations for each compound.A total of 20 larvae were exposed to larvicides for each replicate and monitored at intervals of 12,24,48 and 72 h.Larvae monitoring was done on basis of dead and live larvae in all intervals.Results:All assayed compounds were larvicides and presented varying degrees of larval toxicity,with LC50 values ranging from 1.28 to 1 938.92 mg/L depending on the treatment time(12,24,48 or 72 h).(-)-Perillyl alcohol presented the strongest larvicidal activity towards Anopheles gambiae larvae,with LC_(50) values of 73.60,18.36,1.72 and1.28 mg/L after 12,24,48 and 72 h of exposure,respectively.The next strongest were(-)-isopulegol(LC_(50)= 135.10,49.39,34.39 and 20.22 mg/L) and(-)-carvone epoxide(LC_(50)= 168.86,124.74,80.84 and 23.46 mg/L).After 12,24 and 48 h of treatment,hydroxydihydrocarvone was the least toxic compound,with LC_(50) values of 1 938.92,1 172.18 and 401.03 mg/L,respectively.Conclusions:The data obtained in this study suggest that all evaluated monoterpenes,especially(-)-perillyl alcohol,have remarkable larvicidal effects and may be considered as potential sources for the development of suitable natural larvicides for mosquito management programs.Further small-scale field trials should be conducted.
文摘The epsilon class glutathione-S-transferase of Anopheles gambiae, agGSTe2, is capable of metabolizing DDT. A molecular docking analysis of DDT with agGSTe2 support an E2 elimination mechanism wherein the glutathione sulfur serves as the base to convert DDT to DDE.
基金Supported by Bill&Melinda GATES Foundation and the Ministry of Higher Education and Scientific Research of Benin.
文摘Objective:To explore ovariole basal body granulations and follicular dilatations for determining physiological age inAnopheles gambiaes.s.(An.gambiaes.s.).Methods:Mosquitoes were collected by using window trap catch and identified morphologically.For the first lot ofmosquitoes,they were dissected,and ovary was left in distilled water for reading ovarian tracheoles and the second was cut and transferred to another blade in a physiological liquid for verification of ovariole basal body granulations.The same approach was followed with the second lot of mosquitoes where follicular dilatations were found after classic dilaceration of ovaries were transferred into physiological liquid.The other body parts of mosquitoes were used to identify the species of theAn.gambiaes.s.complex by PCR.Results:Among the 123An.gambiae s.s.of the first lot,the method of Detinova determined the age of 89 mosquitoes versus 114 for the observation of granulations(P>0.05).Among the 112An.gambiae s.s.of the second lot,the method of Detinova determined the age of 84 mosquitoes versus 93 for the observation of follicular dilatations(P>0.05).Unlike the method of Detinova,observation of follicular dilatations and basal body granulations of ovarioles were possible beyond the stage II Christophers.Conclusions:Overall,the observation of follicular dilatations and ovariole basal body granulations are reliable for the determination of the physiological age inAn.gambiaes.s.Furthermore,these two methods can be used beyond the stage II.
