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Sample records for anopheles darlingi transmission

  1. The Genome of Anopheles darlingi, the main neotropical malaria vector

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    Marinotti, Osvaldo; Cerqueira, Gustavo C.; de Almeida, Luiz Gonzaga Paula; Ferro, Maria Inês Tiraboschi; Loreto, Elgion Lucio da Silva; Zaha, Arnaldo; Teixeira, Santuza M. R.; Wespiser, Adam R.; Almeida e Silva, Alexandre; Schlindwein, Aline Daiane; Pacheco, Ana Carolina Landim; da Silva, Artur Luiz da Costa; Graveley, Brenton R.; Walenz, Brian P.; Lima, Bruna de Araujo; Ribeiro, Carlos Alexandre Gomes; Nunes-Silva, Carlos Gustavo; de Carvalho, Carlos Roberto; Soares, Célia Maria de Almeida; de Menezes, Claudia Beatriz Afonso; Matiolli, Cleverson; Caffrey, Daniel; Araújo, Demetrius Antonio M.; de Oliveira, Diana Magalhães; Golenbock, Douglas; Grisard, Edmundo Carlos; Fantinatti-Garboggini, Fabiana; de Carvalho, Fabíola Marques; Barcellos, Fernando Gomes; Prosdocimi, Francisco; May, Gemma; de Azevedo Junior, Gilson Martins; Guimarães, Giselle Moura; Goldman, Gustavo Henrique; Padilha, Itácio Q. M.; Batista, Jacqueline da Silva; Ferro, Jesus Aparecido; Ribeiro, José M. C.; Fietto, Juliana Lopes Rangel; Dabbas, Karina Maia; Cerdeira, Louise; Agnez-Lima, Lucymara Fassarella; Brocchi, Marcelo; de Carvalho, Marcos Oliveira; Teixeira, Marcus de Melo; Diniz Maia, Maria de Mascena; Goldman, Maria Helena S.; Cruz Schneider, Maria Paula; Felipe, Maria Sueli Soares; Hungria, Mariangela; Nicolás, Marisa Fabiana; Pereira, Maristela; Montes, Martín Alejandro; Cantão, Maurício E.; Vincentz, Michel; Rafael, Miriam Silva; Silverman, Neal; Stoco, Patrícia Hermes; Souza, Rangel Celso; Vicentini, Renato; Gazzinelli, Ricardo Tostes; Neves, Rogério de Oliveira; Silva, Rosane; Astolfi-Filho, Spartaco; Maciel, Talles Eduardo Ferreira; Ürményi, Turán P.; Tadei, Wanderli Pedro; Camargo, Erney Plessmann; de Vasconcelos, Ana Tereza Ribeiro

    2013-01-01

    Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector–human and vector–parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi. PMID:23761445

  2. Dynamical Mapping of Anopheles darlingi Densities in a Residual Malaria Transmission Area of French Guiana by Using Remote Sensing and Meteorological Data

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    Adde, Antoine; Roux, Emmanuel; Mangeas, Morgan; Dessay, Nadine; Nacher, Mathieu; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

    2016-01-01

    Local variation in the density of Anopheles mosquitoes and the risk of exposure to bites are essential to explain the spatial and temporal heterogeneities in the transmission of malaria. Vector distribution is driven by environmental factors. Based on variables derived from satellite imagery and meteorological observations, this study aimed to dynamically model and map the densities of Anopheles darlingi in the municipality of Saint-Georges de l’Oyapock (French Guiana). Longitudinal sampling sessions of An. darlingi densities were conducted between September 2012 and October 2014. Landscape and meteorological data were collected and processed to extract a panel of variables that were potentially related to An. darlingi ecology. Based on these data, a robust methodology was formed to estimate a statistical predictive model of the spatial-temporal variations in the densities of An. darlingi in Saint-Georges de l’Oyapock. The final cross-validated model integrated two landscape variables—dense forest surface and built surface—together with four meteorological variables related to rainfall, evapotranspiration, and the minimal and maximal temperatures. Extrapolation of the model allowed the generation of predictive weekly maps of An. darlingi densities at a resolution of 10-m. Our results supported the use of satellite imagery and meteorological data to predict malaria vector densities. Such fine-scale modeling approach might be a useful tool for health authorities to plan control strategies and social communication in a cost-effective, targeted, and timely manner. PMID:27749938

  3. Behavioral heterogeneity of Anopheles darlingi (Diptera: Culicidae) and malaria transmission dynamics along the Maroni River, Suriname, French Guiana.

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    Hiwat, H; Issaly, J; Gaborit, P; Somai, A; Samjhawan, A; Sardjoe, P; Soekhoe, T; Girod, R

    2010-03-01

    The border area between Suriname and French Guiana is considered the most affected malaria area in South America. A one-year cooperative malaria vector study was performed by the two countries, between March 2004 and February 2005, in four villages. Anopheles darlingi proved to be the most abundant anopheline species. Human biting rates differed between villages. The differential effect of high rainfall on mosquito densities in the villages suggests variation in breeding sites. Overall parity rates were low, with means varying from 0.31 to 0.56 per study site. Of the 2045 A. darlingi mosquitoes collected, 13 were found to be infected with Plasmodium: ten P. falciparum, two P. malariae and one mixed P. malariae/P. vivax. The overall annual entomological inoculation rates in the villages ranged from 8.7 to 66.4. There was an apparent lack of relationship between number of malaria cases and periods of high mosquito density. The tendency of Anopheles darlingi to bite during sleeping hours provides opportunity for malaria control using impregnated bed nets, a strategy just introduced in Suriname that may also find its way into French Guiana.

  4. Annual variations in the number of malaria cases related to two different patterns of Anopheles darlingi transmission potential in the Maroni area of French Guiana

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    Issaly Jean

    2010-03-01

    Full Text Available Abstract Background With an Annual Parasite Incidence (API of 132.1, in the high and moderate risks zones, the Maroni area of French Guiana has the second highest malaria incidence of South-America after Guyana (API = 183.54 and far above Brazil (API = 28.25. Malaria transmission is occurring despite strong medical assistance and active vector control, based on general WHO recommendations. This situation is generated by two main factors that are the social and cultural characteristics of this border area, where several ethnic groups are living, and the lack of understanding of transmission dynamics of the main mosquito vector, Anopheles darlingi. In this context, entomological data collected in two villages belonging to two different ethnic groups of the French border of the Maroni River, were retrospectively analysed to find out how the mosquito bionomics are related to the malaria transmission patterns. Methods Data were provided by human landing catches of mosquitoes carried out each month for two years in two villages belonging to two ethnic groups, the Amerindians Wayanas and the Aloukous of African origin. The mosquitoes were sorted by species, sex, date, hour and place of collection and processed for Plasmodium sp. parasite detection. The data were compiled to provide the following variables: human biting rates (HBR, parity rates (PR, numbers of infective bites (IB, entomological inoculation rates (EIR and numbers of infected mosquitoes surviving enough to transmit (IMT. Spatial and temporal differences of variables between locations and during the night were tested by the Kruskall-Wallis analysis of variance to find out significant variations. Results The populations of the main mosquito vector An. darlingi showed significant variations in the spatial and temporal HBR/person/night and HBR/person/hour, IB/person/month and IB/person/hour, and IMT/village/night and IMT/village/hour. In the village of Loca (Aloukous, the IMT peaked from June

  5. High malaria transmission in a forested malaria focus in French Guiana: How can exophagic Anopheles darlingi thwart vector control and prevention measures?

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    Vezenegho, Samuel B; Adde, Antoine; de Santi, Vincent Pommier; Issaly, Jean; Carinci, Romuald; Gaborit, Pascal; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

    2016-01-01

    In French Guiana, malaria vector control and prevention relies on indoor residual spraying and distribution of long lasting insecticidal nets. These measures are based on solid epidemiological evidence but reveal a poor understanding of the vector. The current study investigated the behaviour of both vectors and humans in relation to the ongoing prevention strategies. In 2012 and 2013, Anopheles mosquitoes were sampled outdoors at different seasons and in various time slots. The collected mosquitoes were identified and screened for Plasmodium infection. Data on human behaviour and malaria episodes were obtained from an interview. A total of 3,135 Anopheles mosquitoes were collected, of which Anopheles darlingi was the predominant species (96.2%). For the December 2012-February 2013 period, the Plasmodium vivax infection rate for An. darlingi was 7.8%, and the entomological inoculation rate was 35.7 infective bites per person per three-month span. In spite of high bednet usage (95.7%) in 2012 and 2013, 52.2% and 37.0% of the participants, respectively, had at least one malaria episode. An. darlingi displayed heterogeneous biting behaviour that peaked between 20:30 and 22:30; however, 27.6% of the inhabitants were not yet protected by bednets by 21:30. The use of additional individual and collective protective measures is required to limit exposure to infective mosquito bites and reduce vector densities. PMID:27653361

  6. High malaria transmission in a forested malaria focus in French Guiana: How can exophagic Anopheles darlingi thwart vector control and prevention measures?

    Science.gov (United States)

    Vezenegho, Samuel B; Adde, Antoine; Pommier de Santi, Vincent; Issaly, Jean; Carinci, Romuald; Gaborit, Pascal; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

    2016-09-01

    In French Guiana, malaria vector control and prevention relies on indoor residual spraying and distribution of long lasting insecticidal nets. These measures are based on solid epidemiological evidence but reveal a poor understanding of the vector. The current study investigated the behaviour of both vectors and humans in relation to the ongoing prevention strategies. In 2012 and 2013, Anopheles mosquitoes were sampled outdoors at different seasons and in various time slots. The collected mosquitoes were identified and screened for Plasmodium infection. Data on human behaviour and malaria episodes were obtained from an interview. A total of 3,135 Anopheles mosquitoes were collected, of which Anopheles darlingi was the predominant species (96.2%). For the December 2012-February 2013 period, the Plasmodium vivax infection rate for An. darlingi was 7.8%, and the entomological inoculation rate was 35.7 infective bites per person per three-month span. In spite of high bednet usage (95.7%) in 2012 and 2013, 52.2% and 37.0% of the participants, respectively, had at least one malaria episode. An. darlingi displayed heterogeneous biting behaviour that peaked between 20:30 and 22:30; however, 27.6% of the inhabitants were not yet protected by bednets by 21:30. The use of additional individual and collective protective measures is required to limit exposure to infective mosquito bites and reduce vector densities.

  7. LARVICIDAL ACTIVITY OF Bacillus sphaericus 2362 AGAINST Anopheles nuneztovari, Anopheles darlingi AND Anopheles braziliensis (DIPTERA, CULICIDAE

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    RODRIGUES Iléa Brandão

    1999-01-01

    Full Text Available In this present study, preliminary data was obtained regarding the mortality rate of the Amazonian anophelines, Anopheles nuneztovari, Anopheles darlingi and Anopheles braziliensis when subjected to treatment with Bacillus sphaericus strain 2362, the WHO standard strain. Initially, experiments were conducted to test the mortality rate of the three species of anopheline larvae. The third larval instar of An. nuneztovari and the second and third larval instars of An. darlingi proved to be the least susceptible. In other experiments, the same three mosquito species were tested with the standard strain 2362, An. nuneztovari was the least susceptible to this insect pathogen, while An. braziliensis was the most susceptible. This latter species showed a difference in the level of LC50 concentration, when compared to the former, of 2.4, 2.5 and 1.8 in readings taken 24, 48 and 72 hours after exposure to the bacillus.

  8. Is there an efficient trap or collection method for sampling Anopheles darlingi and other malaria vectors that can describe the essential parameters affecting transmission dynamics as effectively as human landing catches? - A Review

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    José Bento Pereira Lima

    2014-08-01

    Full Text Available Distribution, abundance, feeding behaviour, host preference, parity status and human-biting and infection rates are among the medical entomological parameters evaluated when determining the vector capacity of mosquito species. To evaluate these parameters, mosquitoes must be collected using an appropriate method. Malaria is primarily transmitted by anthropophilic and synanthropic anophelines. Thus, collection methods must result in the identification of the anthropophilic species and efficiently evaluate the parameters involved in malaria transmission dynamics. Consequently, human landing catches would be the most appropriate method if not for their inherent risk. The choice of alternative anopheline collection methods, such as traps, must consider their effectiveness in reproducing the efficiency of human attraction. Collection methods lure mosquitoes by using a mixture of olfactory, visual and thermal cues. Here, we reviewed, classified and compared the efficiency of anopheline collection methods, with an emphasis on Neotropical anthropophilic species, especially Anopheles darlingi, in distinct malaria epidemiological conditions in Brazil.

  9. Anopheles darlingi and Anopheles marajoara (Diptera: Culicidae susceptibility to pyrethroids in an endemic area of the Brazilian Amazon

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    Allan Kardec Ribeiro Galardo

    2015-12-01

    Full Text Available Abstract: INTRODUCTION: This study aimed to evaluate the susceptibility of Anopheles darlingi Root (1926 and Anopheles marajoara Galvão & Damasceno (1942 to pyrethroids used by the National Malaria Control Program in Brazil. METHODS: Mosquitoes from Amapá, Brazilian Amazon, were assessed for resistance to cypermethrin, deltamethrin, and alpha-cypermethrin. Insecticide-impregnated bottles were used as suggested by the CDC/Atlanta. RESULTS: Diagnostic dose for Anopheles darlingi was 12.5µg/bottle during 30 min of exposure. Concentrations for Anopheles marajoara were 20µg/bottle of cypermethrin and deltamethrin and 12.5µg/bottle of alpha-cypermethrin. CONCLUSIONS : No resistance was recorded for Anopheles darlingi , but Anopheles marajoara requires attention.

  10. Systematics and Population Level Analysis of Anopheles darlingi

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    Conn JE

    1998-01-01

    Full Text Available A new phylogenetic analysis of the Nyssorhynchus subgenus (Danoff-Burg and Conn, unpub. data using six data sets {morphological (all life stages; scanning electron micrographs of eggs; nuclear ITS2 sequences; mitochondrial COII, ND2 and ND6 sequences} revealed different topologies when each data set was analyzed separately but no heterogeneity between the data sets using the arn test. Consequently, the most accurate estimate of the phylogeny was obtained when all the data were combined. This new phylogeny supports a monophyletic Nyssorhynchus subgenus but both previously recognized sections in the subgenus (Albimanus and Argyritarsis were demonstrated to be paraphyletic relative to each other and four of the seven clades included species previously placed in both sections. One of these clades includes both Anopheles darlingi and An. albimanus, suggesting that the ability to vector malaria effectively may have originated once in this subgenus. Both a conserved (315 bp and a variable (425 bp region of the mitochondrial COI gene from 15 populations of An. darlingi from Belize, Bolivia, Brazil, French Guiana, Peru and Venezuela were used to examine the evolutionary history of this species and to test several analytical assumptions. Results demonstrated (1 parsimony analysis is equally informative compared to distance analysis using NJ; (2 clades or clusters are more strongly supported when these two regions are combined compared to either region separately; (3 evidence (in the form of remnants of older haplotype lineages for two colonization events; and (4 significant genetic divergence within the population from Peixoto de Azevedo (State of Mato Grosso, Brazil. The oldest lineage includes populations from Peixoto, Boa Vista (State of Roraima and Dourado (State of São Paulo.

  11. Limited Diversity of Anopheles Darlingi in The Peruvian Amazon Region of Iquitos

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    Pinedo-Cancino, Viviana; Sheen, Patricia; Tarazona-Santos, Eduardo; OSWALD, WILLIAM E.; JERI, CESAR; VITTOR, AMY YOMIKO; Patz, Jonathan A.; Gilman, Robert H.

    2006-01-01

    Anopheles darlingi is the most important malaria vector in the Amazon basin of South America, and is capable of transmitting both Plasmodium falciparum and P. vivax. To understand the genetic structure of this vector in the Amazonian region of Peru, a simple polymerase chain reaction (PCR)-based test to identify this species of mosquito was used. A random amplified polymorphic DNA-PCR was used to study genetic variation at the micro-geographic level in nine geographically separate populations...

  12. GNBP domain of Anopheles darlingi: are polymorphic inversions and gene variation related to adaptive evolution?

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    Bridi, L C; Rafael, M S

    2016-02-01

    Anopheles darlingi is the main malaria vector in humans in South America. In the Amazon basin, it lives along the banks of rivers and lakes, which responds to the annual hydrological cycle (dry season and rainy season). In these breeding sites, the larvae of this mosquito feed on decomposing organic and microorganisms, which can be pathogenic and trigger the activation of innate immune system pathways, such as proteins Gram-negative binding protein (GNBP). Such environmental changes affect the occurrence of polymorphic inversions especially at the heterozygote frequency, which confer adaptative advantage compared to homozygous inversions. We mapped the GNBP probe to the An. darlingi 2Rd inversion by fluorescent in situ hybridization (FISH), which was a good indicator of the GNBP immune response related to the chromosomal polymorphic inversions and adaptative evolution. To better understand the evolutionary relations and time of divergence of the GNBP of An. darlingi, we compared it with nine other mosquito GNBPs. The results of the phylogenetic analysis of the GNBP sequence between the species of mosquitoes demonstrated three clades. Clade I and II included the GNBPB5 sequence, and clade III the sequence of GNBPB1. Most of these sequences of GNBP analyzed were homologous with that of subfamily B, including that of An. gambiae (87 %), therefore suggesting that GNBP of An. darling belongs to subfamily B. This work helps us understand the role of inversion polymorphism in evolution of An. darlingi.

  13. Limited Diversity of Anopheles Darlingi in The Peruvian Amazon Region of Iquitos

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    PINEDO-CANCINO, VIVIANA; SHEEN, PATRICIA; TARAZONA-SANTOS, EDUARDO; OSWALD, WILLIAM E.; JERI, CESAR; VITTOR, AMY YOMIKO; PATZ, JONATHAN A.; GILMAN, ROBERT H.

    2006-01-01

    Anopheles darlingi is the most important malaria vector in the Amazon basin of South America, and is capable of transmitting both Plasmodium falciparum and P. vivax. To understand the genetic structure of this vector in the Amazonian region of Peru, a simple polymerase chain reaction (PCR)-based test to identify this species of mosquito was used. A random amplified polymorphic DNA-PCR was used to study genetic variation at the micro-geographic level in nine geographically separate populations of An. darlingi collected in areas with different degrees of deforestation surrounding the city of Iquitos. Within-population genetic diversity in nine populations, as quantified by the expected heterozygosity (HE), ranged from 0.27 to 0.32. Average genetic distance (FST) among these populations was 0.017. These results show that the nine studied populations are highly homogeneous, suggesting that strategies can be developed to combat this malaria vector as a single epidemiologic unit. PMID:16896125

  14. Collapse of Anopheles darlingi populations in Suriname after introduction of insecticide-treated nets (ITNs); malaria down to near elimination level.

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    Hiwat, Hélène; Mitro, Sutrisno; Samjhawan, Ashok; Sardjoe, Prem; Soekhoe, Treyanti; Takken, Willem

    2012-04-01

    A longitudinal study of malaria vectors was carried out in three villages in Suriname between 2006 and 2010. During 13,392 man hours of collections, 3,180 mosquitoes were collected, of which 33.7% were anophelines. Of these, Anopheles darlingi accounted for 88.1%, and An. nuneztovari accounted for 11.1%. The highest mean An. darlingi human biting rate (HBR) observed per survey was 1.43 bites/man per hour outdoor and 1.09 bites/man per hour indoor; 2 An. darlingi of the 683 tested were infected with Plasmodium falciparum. The anopheline HBR decreased to zero after the onset of malaria intervention activities, including insecticide-treated net (ITN) distribution, in 2006. Malaria transmission decreased to pre-elimination levels. It is concluded that the combination of ITN and climatic events has led to the collapse of malaria vector populations in the study sites in the interior of the country. The results are discussed in relation to the stability of malaria transmission in areas with low-density human populations.

  15. Intensive trapping of blood-fed Anopheles darlingi in Amazonian Peru reveals unexpectedly high proportions of avian blood-meals

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    Saavedra, Marlon P.; Bickersmith, Sara A.; Prussing, Catharine; Michalski, Adrian; Tong Rios, Carlos; Vinetz, Joseph M.; Conn, Jan E.

    2017-01-01

    Anopheles darlingi, the main malaria vector in the Neotropics, has been considered to be highly anthropophilic. However, many behavioral aspects of this species remain unknown, such as the range of blood-meal sources. Barrier screens were used to collect resting Anopheles darlingi mosquitoes from 2013 to 2015 in three riverine localities (Lupuna, Cahuide and Santa Emilia) in Amazonian Peru. Overall, the Human Blood Index (HBI) ranged from 0.58–0.87, with no significant variation among years or sites. Blood-meal analysis revealed that humans are the most common blood source, followed by avian hosts (Galliformes-chickens and turkeys), and human/Galliforme mixed-meals. The Forage Ratio and Selection Index both show a strong preference for Galliformes over humans in blood-fed mosquitoes. Our data show that 30% of An. darlingi fed on more than one host, including combinations of dogs, pigs, goats and rats. There appears to be a pattern of host choice in An. darlingi, with varying proportions of mosquitoes feeding only on humans, only on Galliformes and some taking mixed-meals of blood (human plus Galliforme), which was detected in the three sites in different years, indicating that there could be a structure to these populations based on blood-feeding preferences. Mosquito age, estimated in two localities, Lupuna and Cahuide, ranged widely between sites and years. This variation may reflect the range of local environmental factors that influence longevity or possibly potential changes in the ability of the mosquito to transmit the parasite. Of 6,204 resting An. darlingi tested for Plasmodium infection, 0.42% were infected with P. vivax. This study provides evidence for the first time of the usefulness of barrier screens for the collection of blood-fed resting mosquitoes to calculate the Human Blood Index (HBI) and other blood-meal sources in a neotropical malaria endemic setting. PMID:28231248

  16. Comparison of experimental hut entrance and exit behavior between Anopheles darlingi from the Cayo District, Belize, and Zungarococha, Peru.

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    Sachs, Paige; Diaz Rodriguez, Gloria Alicia; Briceno, Ireneo; King, Russell; Achee, Nicole L; Grieco, John P

    2013-12-01

    Anopheles darlingi is a major vector for malaria in Central and South America. Behavioral, ecological, genetic, and morphologic variability has been observed across its wide distribution. Recent studies have documented that 2 distinct genotypes exist for An. darlingi: a northern lineage (Belize, Guatemala, Colombia, Venezuela, and Panama) and a southern lineage (Amazonia and southern Brazil). In order to determine if these genotypes exhibited different behavioral traits, entrance and exit movement patterns between 2 field populations of An. darlingi that represented each genotype were evaluated using experimental huts. The Belize population exhibited bimodal entrance, with peak entry occurring between 7:00-8:00 p.m. and 5:00-6:00 a.m. and peak exiting occurring between 7:00-8:00 p.m. The Peru population exhibited unimodal entrance, with peak entry occurring between 10:00-11:00 p.m. and peak exiting occurring between 11:00-12:00 a.m. with a secondary smaller peak at 2:30 a.m. Entrance and exit behavioral patterns were significantly different between the Belize and Peru populations of An. darlingi (log-rank [Mantel-Cox] P < 0.001). Information from the present study will be used in the future to determine if there is a correlation between genotype and host-seeking behavior and can be used in the present for regional vector risk assessment.

  17. Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

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    Anthony J Cornel

    2016-05-01

    Full Text Available Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1 chromosome, chromosome 2 (n = 7 and 3 (n = 11 were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009. No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies.

  18. Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

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    Cornel, Anthony J; Brisco, Katherine K; Tadei, Wanderli P; Secundino, Nágila FC; Rafael, Miriam S; Galardo, Allan KR; Medeiros, Jansen F; Pessoa, Felipe AC; Ríos-Velásquez, Claudia M; Lee, Yoosook; Pimenta, Paulo FP; Lanzaro, Gregory C

    2016-01-01

    Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies. PMID:27223867

  19. Anopheles species composition explains differences in Plasmodium transmission in La Guajira, northern Colombia.

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    Herrera-Varela, Manuela; Orjuela, Lorena I; Peñalver, Cilia; Conn, Jan E; Quiñones, Martha L

    2014-11-01

    Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

  20. Comportamiento estacional del Anopheles (nyssorhynchus) darlingi root 1926 en localidades de Loreto y Madre de Dios, Perú 1999- 2000

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    Walter León C; Jorge Valle T; Rubén Naupay O; Edwin Tineo V; Angel Rosas A; Mirían Palomino S

    2003-01-01

    Objetivos: Determinar el comportamiento estacional del Anopheles darlingi en las localidades de Santa Clara (Loreto) y Villa Luz (Madre de Dios). Materiales y métodos: En las localidades de Santa Clara y Villa Luz, entre agosto de 1999 y junio de 2000 se realizó mensualmente la inspección de criaderos, colecta de larvas de Anopheles darlingi por el método del cucharón y colecta de mosquitos adultos por el método cebo humano (intradomicilio y peri domicilió), trampa Shannon y refugio animal (e...

  1. First Record of Anopheles darlingi Root (Diptera, Culicidae in the Volta Grande Environmental Reserve, Conceição das Alagoas Municipality, Minas Gerais, Brazil

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    Rafael Martins

    2015-04-01

    Resumo. Três espécimes de Anopheles darlingi Root foram encontrados na reserva ambiental Volta Grande, na área de influência da barragem do Rio Grande construída pela usina hidrelétrica de Volta Grande, em Conceição das Alagoas, Minas Gerais, Brasil. O mosquito An. darlingi é um dos principais vetores da malária humana no Brasil, devido à sua preferência alimentar por sangue humano, um fator que é acentuado pelo comportamento endofílico da espécie. O presente relato poderá ser útil à vigilância entomológica local para monitoramento dos impactos gerados pela formação do reservatório hidrelétrico, uma vez que a presença deste vetor neste tipo de ambiente indica um risco potencial de transmissão da malária.

  2. Population Structure of the Primary Malaria Vector in South America, Anopheles darlingi, Using Isozyme, Random Amplified Polymorphic DNA, Internal Transcribed Spacer 2, and Morphologic Markers

    Science.gov (United States)

    1999-01-01

    derscoring some congruence, in this case, between two dif- ferent molecular markers. Intraspecific variation in the ITS2 region of 21 members of...morphism in the salivary gland chromosomes of Anopheles darlingi. Mosq News 32: 555-565. 29. Tadei WP, Santos JMN, Rabbani MG, 1982. Biologia de ano...Contel EPB, dos Santos JMM, Tadei Wp, 1984. Biologia de Anophelinos Amazonicos. VI. Enzimatica em Anopheles dar- lingi Root (Dipt.: Culicidae). Acta

  3. Collapse of Anopheles darlingi populations in Suriname after introduction of insecticide-treated nets (ITNs); malaria down to near elimination level

    NARCIS (Netherlands)

    Hiwat, H.; Mitro, S.; Samjhawan, A.; Sardjoe, P.; Soekhoe, T.; Takken, W.

    2012-01-01

    A longitudinal study of malaria vectors was carried out in three villages in Suriname between 2006 and 2010. During 13,392 man hours of collections, 3,180 mosquitoes were collected, of which 33.7% were anophelines. Of these, Anopheles darlingi accounted for 88.1%, and An. nuneztovari accounted for 1

  4. Evaluation of Methods for Sampling the Malaria Vector Anopheles darlingi (Diptera, Culicidae) in Suriname and the Relation With Its Biting Behavior

    NARCIS (Netherlands)

    Hiwat-van Laar, H.; Rijk, de M.; Andriessen, R.; Koenraadt, C.J.M.; Takken, W.

    2011-01-01

    The effectiveness of CO2-baited and human-baited mosquito traps for the sampling of Anopheles darlingi Root was evaluated and compared with human landing collections in Suriname. Biting preferences of this mosquito on a human host were studied and related to trapping data. Traps used were the Center

  5. Heterochromatin variation in chromosomes of Anopheles (Nyssorhynchus darlingi Root and A.(N. nuneztovari Gabaldón (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Míriam Silva Rafael

    2000-03-01

    Full Text Available C-banding was used to study the variations in heterochromatic block markings in chromosomes of Anopheles darlingi and A. nuneztovari from Manaus, State of Amazonas, and Macapá, State of Amapá, Brazil. Both species had two differently shaped X chromosomes and a Y chromosome that was entirely heterochromatic. The X1 chromosome of A. darlingi had markings that extended 1/3 of the total length whereas in the X2 chromosome the markings were located around the centromeric region. The markings on autosomal chromosomes were concentrated in the centromeric region in both species, with a heterochromatic block in one arm of chromosome II of A. darlingi. A. nuneztovari had three heterochromatic blocks in chromosome X1 (longer and two blocks in X2 (shorter. X2X2 females were not detected in either species. The X1 and X2 chromosomes of males were found in A. darlingi, whereas in A. nuneztovari only the X1 chromosome was detected. Only intraspecific variation was found in heterochromatic block markings in the sex chromosomes and autosomes in the two populations of both species at each location.Pela técnica do bandamento C detectou-se variação de marcação dos blocos heterocromáticos dos cromossomos de A. darlingi e A. nuneztovari de Manaus, Amazonas, e de Macapá, Amapá, Brasil. Os cromossomos sexuais de ambas as espécies mostraram duas formas de cromossomos X e o Y foi totalmente heterocromático. No cromossomo X1 de A. darlingi a marcação atingiu 1/3 e no cromossomo X2 foi apenas na região centromérica. Nos autossomos de ambas as espécies as marcações foram constantes nas regiões centroméricas, e o cromossomo II de A. darlingi mostrou um bloco heterocromático em um dos braços. A. nuneztovari mostrou polimorfismo de tamanho para o cromossomo X, tendo o X maior (X1 três blocos e o menor (X2 dois blocos heterocromáticos. Fêmeas homozigotas (X2X2 não foram detectadas nas duas localidades. Em machos de A. darlingi foram encontrados os

  6. Population structure of the malaria vector Anopheles darlingi in a malaria-endemic region of Eastern Amazonian Brazil

    DEFF Research Database (Denmark)

    Conn, Jan E.; Vineis, Joseph H.; Bollback, Jonathan Paul;

    2006-01-01

    Anopheles darlingi is the primary malaria vector in Latin America, and is especially important in Amazonian is the primary malaria vector in Latin America, and is especially important in Amazonian Brazil. Historically, control efforts have been focused on indoor house spraying using a variety...... malaria epidemic. In contrast, although An. darlingi was eradicated from some districts of the city of Belem (the capital of Para State) in 1968 to reduce malaria, populations around the water protection area in the eastern district were treated only briefly. To investigate the population structure of An...

  7. Habitat suitability mapping of Anopheles darlingi in the surroundings of the Manso hydropower plant reservoir, Mato Grosso, Central Brazil

    Directory of Open Access Journals (Sweden)

    Miyazaki Rosina D

    2007-03-01

    Full Text Available Abstract Background Hydropower plants provide more than 78 % of Brazil's electricity generation, but the country's reservoirs are potential new habitats for main vectors of malaria. In a case study in the surroundings of the Manso hydropower plant in Mato Grosso state, Central Brazil, habitat suitability of Anopheles darlingi was studied. Habitat profile was characterized by collecting environmental data. Remote sensing and GIS techniques were applied to extract additional spatial layers of land use, distance maps, and relief characteristics for spatial model building. Results Logistic regression analysis and ROC curves indicate significant relationships between the environment and presence of An. darlingi. Probabilities of presence strongly vary as a function of land cover and distance from the lake shoreline. Vector presence was associated with spatial proximity to reservoir and semi-deciduous forests followed by Cerrado woodland. Vector absence was associated with open vegetation formations such as grasslands and agricultural areas. We suppose that non-significant differences of vector incidences between rainy and dry seasons are associated with the availability of anthropogenic breeding habitat of the reservoir throughout the year. Conclusion Satellite image classification and multitemporal shoreline simulations through DEM-based GIS-analyses consist in a valuable tool for spatial modeling of A. darlingi habitats in the studied hydropower reservoir area. Vector presence is significantly increased in forested areas near reservoirs in bays protected from wind and wave action. Construction of new reservoirs under the tropical, sub-humid climatic conditions should therefore be accompanied by entomologic studies to predict the risk of malaria epidemics.

  8. Population genetic structure of the major malaria vector Anopheles darlingi (Diptera: Culicidae from the Brazilian Amazon, using microsatellite markers

    Directory of Open Access Journals (Sweden)

    Vera Margarete Scarpassa

    2007-06-01

    Full Text Available The population genetic structure of Anopheles darlingi, the major human malaria vector in the Neotropics, was examined using seven microsatellite loci from nine localities in central and western Amazonian Brazil. High levels of genetic variability were detected (5-25 alleles per locus; H E = 0.519-0.949. There was deviation from Hardy-Weinberg Equilibrium for 59.79% of the tests due to heterozygote deficits, while the analysis of linkage disequilibrium was significant for only two of 189 (1.05% tests, most likely caused by null alleles. Genetic differentiation (F ST = 0.001-0.095; Nm = 4.7-363.8 indicates that gene flow is extensive among locations < 152 km apart (with two exceptions and reduced, but not absent, at a larger geographic scale. Genetic and geographic distances were significantly correlated (R² = 0.893, P < 0.0002, supporting the isolation by distance (IBD model. The overall estimate of Ne was 202.4 individuals under the linkage disequilibrium model, and 8 under the heterozygote excess model. Analysis of molecular variance showed that nearly all variation (~ 94% was within sample locations. The UPGMA phenogram clustered the samples geographically, with one branch including 5/6 of the state of Amazonas localities and the other branch the Acre, Rondônia, and remaining Amazonas localities. Taken together, these data suggest little genetic structure for An. darlingi from central and western Amazonian Brazil. These findings also imply that the IBD model explains nearly all of the differentiation detected. In practical terms, populations of An. darlingi at distances < 152 km should respond similarly to vector control measures, because of high gene flow.

  9. Comportamento exófilo de Anopheles darlingi Root, em região meridional do Brasil Exophilic behavior of Anopheles darlingi Root in a Southern Region of Brazil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1987-08-01

    Full Text Available Observou-se o comportamento da população "Araraquara" de Anopheles darlingi, em seu ambiente original e em relação à sua atividade exófila com isca humana. As coletas foram realizadas às margens do rio Jacaré-Pepira, no Município de Dourado, Estado de São Paulo, Brasil. O ciclo nictemeral caracteriza-se pelo aspecto bimodal, com os dois picos correspondentes a cada crepúsculo, ou seja, vespertino e matutino. O seu detalhamento permitiu detectar bimodalidade secundária, subdividindo cada pico em um eocrepuscular precedendo ao intracrepuscular propriamente dito. A variação sazonal revelou aumento do número de mosquitos na estação chuvosa e quente e nítido declínio na seca e fria. Embora com dados insuficientes, houve indícios de que o An. albitarsis local, apresente também ritmo bimodal em seu ciclo diário de atividade.Fortnightly 25-hour catches, with human bait, were carried out in a modified environment of the "Jacaré-Pepira" River, Dourado County, S. Paulo, Brazil which is the original region of the "Araraquara" strain of Anopheles darlingi. The exophylic biting activity was mostly nocturnal with bimodal rhythm, showing two clear peaks corresponding, respectively, to dusk and dawn. Going into crepuscular details two secondary peaks were observed, an eocrepuscular preceding the intracrepuscular one As, by means of chromosome arrangement studies, this population was found to have low polymorphism, it is supposed that those rhythms are, in a good measure, of endogenous command. The number of mosquitoes biting increased during the hot, wet season and decreased remarkably during the dry, cold one. There was some evidence that An albitarsis may also show a bimodality in its nocturnal biting activity rhythm.

  10. Efetividade de formulações nanoestruturadas com dilapiol (Piper aduncum Linnaeus, 1753) e piretróides no controle de Anopheles darlingi Root, 1926

    OpenAIRE

    GOMES,Erika de Oliveira

    2012-01-01

    A malária é uma doença infecciosa, causada por protozoários do gênero Plasmodium, transmitidos ao homem pela picada de mosquitos do gênero Anopheles. O objetivo deste trabalho foi analisar o dilapiol isolado de Piper aduncum e em formulações nanoestruturadas utilizado contra adultos de Anopheles darlingi, identificando-se o potencial de repelência, o efeito sinergístico quando associado aos inseticidas químicos Deltametrina, Cipermetrina e Alfacipermetrina, e o efeito do contato tópico destes...

  11. Evaluation of methods for sampling the malaria vector Anopheles darlingi (Diptera, Culicidae) in Suriname and the relation with its biting behavior.

    Science.gov (United States)

    Hiwat, H; De Rijk, M; Andriessen, R; Koenraadt, C J M; Takken, W

    2011-09-01

    The effectiveness of CO2-baited and human-baited mosquito traps for the sampling of Anopheles darlingi Root was evaluated and compared with human landing collections in Suriname. Biting preferences of this mosquito on a human host were studied and related to trapping data. Traps used were the Centers for Disease Control and Prevention Miniature Light trap, the BG Sentinel mosquito trap, the Mosquito Magnet Liberty Plus mosquito trap (MM-Plus), and a custom-designed trap. Carbon dioxide and humans protected by a bed net were used as bait in the studies. The number of An. darlingi collected was greater with human landing collections than with all other collection methods. An. darlingi did not show a preference for protected humans over CO2 bait. The BG Sentinel mosquito trap with CO2 or human odor as bait and the MM-Plus proved the best alternative sampling tools for An. darlingi. The BG Sentinel mosquito trap with CO2 or human odor as bait was also very efficient at collecting Culex spp. In a field study on biting preferences of wild An. darlingi, the females showed directional biting behavior (P < 0.001), with a majority of females (93.3%) biting the lower legs and feet when approaching a seated human host. Higher efficiency of the closer-to-the-ground collecting MM-Plus and BG Sentinel mosquito trap when compared with the other trapping methods may be a result of a possible preference of this mosquito species for low-level biting. It is concluded that odor-baited sampling systems can reliably collect An. darlingi, but the odor bait needs to be improved, for instance, by including host-specific volatiles, to match live human baits.

  12. Comportamiento estacional del Anopheles (nyssorhynchus darlingi root 1926 en localidades de Loreto y Madre de Dios, Perú 1999- 2000

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    Walter León C

    2003-03-01

    Full Text Available Objetivos: Determinar el comportamiento estacional del Anopheles darlingi en las localidades de Santa Clara (Loreto y Villa Luz (Madre de Dios. Materiales y métodos: En las localidades de Santa Clara y Villa Luz, entre agosto de 1999 y junio de 2000 se realizó mensualmente la inspección de criaderos, colecta de larvas de Anopheles darlingi por el método del cucharón y colecta de mosquitos adultos por el método cebo humano (intradomicilio y peri domicilió, trampa Shannon y refugio animal (extradomicilio. Se calcularon los indicadores: criadero positivo y densidad larvaria por cucharonada, índice de picadura hombre noche (IPHN, índice de picadura hombre hora (IPHH, índice esporozoítico y tasa de paridad. Resultados: El IPHN en ambas localidades se incrementó en la estación lluviosa con los valores más altos en mayo (Santa Clara y febrero (Villa Luz. En Santa Clara, el comportamiento de la picadura del Anopheles darlingi de agosto a diciembre de 1999, fue unimodal presentándose el pico de IPHH entre las 19.00 y 21.00 horas; sin embargo, de marzo a junio de 2000, el comportamiento fue bimodal con dos picos del IPHH: entre las 19.00 y 22.00 horas, y entre las 2.00 y 4.00 horas. En Villa Luz, el comportamiento de la picadura, de agosto a junio de 1999, se mantuvo unimodal, con el pico de IPHH entre las 21.00 y 24.00 horas. Las especies inmaduras de Anopheles darlingi representaron menos del 20% de las larvas encontradas en los criaderos permanentes. Conclusiones: El Anopheles darlingi presenta mayor densidad poblacional en meses de estación lluviosa, con comportamientos de picadura distintos según localidad y estación. Los criaderos evaluados no serían criaderos tan importantes de esta especie.

  13. Microsatellite data suggest significant population structure and differentiation within the malaria vector Anopheles darlingi in Central and South America

    Directory of Open Access Journals (Sweden)

    Achee Nicole L

    2008-03-01

    Full Text Available Abstract Background Anopheles darlingi is the most important malaria vector in the Neotropics. An understanding of A. darlingi's population structure and contemporary gene flow patterns is necessary if vector populations are to be successfully controlled. We assessed population genetic structure and levels of differentiation based on 1,376 samples from 31 localities throughout the Peruvian and Brazilian Amazon and Central America using 5–8 microsatellite loci. Results We found high levels of polymorphism for all of the Amazonian populations (mean RS = 7.62, mean HO = 0.742, and low levels for the Belize and Guatemalan populations (mean RS = 4.3, mean HO = 0.457. The Bayesian clustering analysis revealed five population clusters: northeastern Amazonian Brazil, southeastern and central Amazonian Brazil, western and central Amazonian Brazil, Peruvian Amazon, and the Central American populations. Within Central America there was low non-significant differentiation, except for between the populations separated by the Maya Mountains. Within Amazonia there was a moderate level of significant differentiation attributed to isolation by distance. Within Peru there was no significant population structure and low differentiation, and some evidence of a population expansion. The pairwise estimates of genetic differentiation between Central America and Amazonian populations were all very high and highly significant (FST = 0.1859 – 0.3901, P DA and FST distance-based trees illustrated the main division to be between Central America and Amazonia. Conclusion We detected a large amount of population structure in Amazonia, with three population clusters within Brazil and one including the Peru populations. The considerable differences in Ne among the populations may have contributed to the observed genetic differentiation. All of the data suggest that the primary division within A. darlingi corresponds to two white gene genotypes between Amazonia (genotype 1

  14. Revisión histórica de la distribución de Anopheles (Nyssorhynchus darlingi (Diptera: Culicidae en la amazonía peruana

    Directory of Open Access Journals (Sweden)

    Roberto Fernández

    2014-06-01

    Full Text Available Anopheles (Nyssorhynchus darlingi ha sido reportado desde 1931 en áreas fronterizas del departamento de Loreto, principalmente a lo largo de las fronteras con Brasil y Colombia. En 1994, durante un brote de malaria, An. darlingi fue encontrado en localidades vecinas a Iquitos. En la actualidad, su distribución se ha expandido considerablemente en Loreto. Para los objetivos de este trabajo se realizó una revisión de las referencias bibliográficas disponibles para obtener toda la información posible sobre la distribución de los mosquitos, en particular de los anofelinos en la región Amazónica del país, con énfasis especial en An. darlingi. También se realizaron colectas entomológicas en los departamentos de Madre de Dios y Ucayali con la finalidad de conocer y verificar la distribución de An. darlingi. En la actualidad, la distribución de la especie está circunscrita a localidades al sureste del Perú en localidades fronterizas con Bolivia, en una localidad del río Abujao del departamento de Ucayali, y ampliamente en la región noreste de la cuenca amazónica del departamento de Loreto

  15. Revisión histórica de la distribución de Anopheles (Nyssorhynchus darlingi (Diptera: Culicidae en la amazonía peruana

    Directory of Open Access Journals (Sweden)

    Roberto Fernández

    2014-04-01

    Full Text Available Anopheles (Nyssorhynchus darlingi ha sido reportado desde 1931 en áreas fronterizas del departamento de Loreto, principalmente a lo largo de las fronteras con Brasil y Colombia. En 1994, durante un brote de malaria, An. darlingi fue encontrado en localidades vecinas a Iquitos. En la actualidad, su distribución se ha expandido considerablemente en Loreto. Para los objetivos de este trabajo se realizó una revisión de las referencias bibliográficas disponibles para obtener toda la información posible sobre la distribución de los mosquitos, en particular de los anofelinos en la región Amazónica del país, con énfasis especial en An. darlingi. También se realizaron colectas entomológicas en los departamentos de Madre de Dios y Ucayali con la finalidad de conocer y verificar la distribución de An. darlingi. En la actualidad, la distribución de la especie está circunscrita a localidades al sureste del Perú en localidades fronterizas con Bolivia, en una localidad del río Abujao del departamento de Ucayali, y ampliamente en la región noreste de la cuenca amazónica del departamento de Loreto

  16. Field evaluation of traditionally used plant-based insect repellents and fumigants against the malaria vector Anopheles darlingi in Riberalta, Bolivian Amazon.

    Science.gov (United States)

    Moore, Sarah J; Hill, Nigel; Ruiz, Carmen; Cameron, Mary M

    2007-07-01

    Inexpensive insect repellents may be needed to supplement the use of impregnated bed-nets in the Amazon region, where the primary malaria vector, Anopheles darlingi (Root), is exophilic and feeds in the early evening. Three plants that are traditionally used to repel mosquitoes in Riberalta, Bolivian Amazon, were identified by focus group, and then they were tested against An. darlingi as well as Mansonia indubitans (Dyar & Shannon)/Mansonia titillans (Walker). Cymbopogon citratus (Staph), Guatemalan lemongrass, essential oil at 25% was used as a skin repellent, and it provided 74% protection for 2.5 h against predominantly An. darlingi and 95% protection for 2.5 h against Mansonia spp. Attalea princeps (name not verified) husks, burned on charcoal in the traditional way provided 35 and 51% protection against An. darlingi and Mansonia spp., respectively. Kerosene lamps, often used to light rural homes, were used as a heat source to volatilize 100% Mentha arvensis (Malinv ex. Bailey) essential oil, and they reduced biting by 41% inside traditional homes against Mansonia spp., although they were ineffective outdoors against An. darlingi. All three plant-based repellents provided significant protection compared with controls. Plant-based repellents, although less effective than synthetic alternatives, were shown by focus groups to be more culturally acceptable in this setting, in particular para-menthane-3, 8, idol derived from lemon eucalyptus, Corymbia citriodora (Hook). Plant-based repellents have the potential to be produced locally and therefore sold more cheaply than synthetic commercial repellents. Importantly, their low cost may encourage user compliance among indigenous and marginalized populations.

  17. Distribución geográfica y comportamiento estacional de la picadura del Anopheles (Nyssorhynchus) darlingi Root 1926 en localidades de la frontera Perú-Bolivia, Madre de Dios, Perú

    OpenAIRE

    Edwin Tineo V; Alipio Medina C; César Fallaque S; Luis Chávez C; Salvador Quispe F; Marco Mercado A; Juan Zevallos G; Walter León C; Miriam Palomino S

    2003-01-01

    Objetivos: Determinar la distribución geográfica y el comportamiento estacional de la picadura del Anopheles darlingi en localidades de San Pedro, La Novia, Shiringayoc y Mavila del departamento de Madre de Dios. Materiales y métodos: En estas 4 localidades, durante el periodo comprendido entre junio de 2001 y abril de 2002, se realizó la inspección de criaderos, colecta de larvas de Anopheles darlingi por el método del cucharón y la colecta de mosquitos adultos por el método cebo humano (int...

  18. Larval control of Anopheles (Nyssorhinchus darlingi using granular formulation of Bacillus sphaericus in abandoned gold-miners excavation pools in the Brazilian Amazon Rainforest

    Directory of Open Access Journals (Sweden)

    Allan Kardec Ribeiro Galardo

    2013-09-01

    Full Text Available INTRODUCTION: Use of a Bacillus sphaericus based mosquito larvicide was evaluated as an intervention for malaria vector control at a mining site in Amapá, Brazil. Impacts on larval and adult densities of the primary vector Anopheles darlingi were measured over the course of a 52 week study period. METHODS: In Calçoene, State of Amapá, gold mining activity occurs in 19 mining sites in gold-miners of Lourenço. Large pools are formed in mining sites and naturally colonized by Anopheles darlingi. During one year, the impact of applications of VectoLex(r CG to these larval sources was evaluated. Applications of 20kg/ha were made as needed, based on 10 immature (3rd, 4th instars and pupae surveillance of health and established thresholds. RESULTS: One hundred percent initial control was observed 48h after each treatment. The pools received from 2-10 (5.3±1.6 treatments during the year. The average re-treatment interval in productive pools was 9.4±4.3 weeks. During weeks 3-52 of the study, mean density of late stage larvae was 78% and pupae were 93% lower in the treated pools than in untreated pools (p< 0.0001, n=51 while reduction of adult mosquitoes was 53% in comparison to the untreated area during the last five months of the study, which were the rainy season (p<0.001. CONCLUSIONS: VectoLex(r CG reduced immature Anopheles darlingi infestation levels during the entire study period, and reduced adult mosquito populations during the rainy season.

  19. Larval control of Anopheles (Nyssorhinchus darlingi using granular formulation of Bacillus sphaericus in abandoned gold-miners excavation pools in the Brazilian Amazon Rainforest

    Directory of Open Access Journals (Sweden)

    Allan Kardec Ribeiro Galardo

    2013-04-01

    Full Text Available INTRODUCTION: Use of a Bacillus sphaericus based mosquito larvicide was evaluated as an intervention for malaria vector control at a mining site in Amapá, Brazil. Impacts on larval and adult densities of the primary vector Anopheles darlingi were measured over the course of a 52 week study period. METHODS: In Calçoene, State of Amapá, gold mining activity occurs in 19 mining sites in gold-miners of Lourenço. Large pools are formed in mining sites and naturally colonized by Anopheles darlingi. During one year, the impact of applications of VectoLex(r CG to these larval sources was evaluated. Applications of 20kg/ha were made as needed, based on 10 immature (3rd, 4th instars and pupae surveillance of health and established thresholds. RESULTS: One hundred percent initial control was observed 48h after each treatment. The pools received from 2-10 (5.3±1.6 treatments during the year. The average re-treatment interval in productive pools was 9.4±4.3 weeks. During weeks 3-52 of the study, mean density of late stage larvae was 78% and pupae were 93% lower in the treated pools than in untreated pools (p< 0.0001, n=51 while reduction of adult mosquitoes was 53% in comparison to the untreated area during the last five months of the study, which were the rainy season (p<0.001. CONCLUSIONS: VectoLex(r CG reduced immature Anopheles darlingi infestation levels during the entire study period, and reduced adult mosquito populations during the rainy season.

  20. Distribución geográfica y comportamiento estacional de la picadura del Anopheles (Nyssorhynchus darlingi Root 1926 en localidades de la frontera Perú-Bolivia, Madre de Dios, Perú

    Directory of Open Access Journals (Sweden)

    Edwin Tineo V

    2003-04-01

    Full Text Available Objetivos: Determinar la distribución geográfica y el comportamiento estacional de la picadura del Anopheles darlingi en localidades de San Pedro, La Novia, Shiringayoc y Mavila del departamento de Madre de Dios. Materiales y métodos: En estas 4 localidades, durante el periodo comprendido entre junio de 2001 y abril de 2002, se realizó la inspección de criaderos, colecta de larvas de Anopheles darlingi por el método del cucharón y la colecta de mosquitos adultos por el método cebo humano (intradomicilio y peridomicilio, trampa Shannon y refugio animal (extradomicilio. Se construyó un mapa de ubicación geográfica del vector, calculándose los indicadores: criadero positivo y densidad larvaria por cucharonada, índice de picadura hombre noche (IPHN, indice de picadura hombre hora (IPHH, índice esporozoítico y tasa de paridad. Resultados: Se demostró la presencia de Anopheles darlingi en las localidades de San Pedro, La Novia y Mavila. Las especies inmaduras representaron menos del 12% de las larvas encontradas en los criaderos permanentes. El IPHN en las tres localidades se incrementó en la estación lluviosa (diciembre-abril. La picadura del Anopheles darlingi tuvo un comportamiento ematofágico unimodal, con picos de IPHH entre las 20.00 y 23.00 horas en San Pedro y La Novia; y entre las 20.00 y 22.00 horas en Mavila. Conclusiones: El Anopheles darlingi presenta mayor densidad poblacional en los meses de estación lluviosa, presentando un comportamiento de picadura unimodal con mayor actividad hematofágica entre las 20.00 y 23.00 horas.

  1. Mixed-function oxidases and esterases associated with cross-r esistance between DDT and lambda-cyhalothrin in Anopheles darlingi Root 1926 populations from Colombia

    Directory of Open Access Journals (Sweden)

    Idalyd Fonseca-González

    2009-02-01

    Full Text Available In order to establish the insecticide susceptibility status for Anopheles darlingi in Colombia, and as part of the National Network on Insecticide Resistance Surveillance, five populations of insects from three Colombian states were evaluated. Standardised WHO and CDC bottle bioassays, in addition to microplate biochemical assays, were conducted. Populations with mortality rates below 80% in the bioassays were considered resistant. All field populations were susceptible to deltamethrin, permethrin, malathion and fenitrothion. Resistance to lambda-cyhalothrin and DDT was detected in the Amé-Beté population using both bioassay methods with mortality rates of 65-75%. Enzyme levels related to insecticide resistance, including mixed function oxidases (MFO, non-specific esterases (NSE, glutathione S-transferases and modified acetylcholinesterase were evaluated in all populations and compared with a susceptible natural strain. Only mosquitoes from Amé-Beté presented significantly increased levels of both MFO and NSE, consistent with the low mortalities found in this population. The continued use of lambda-cyhalothrin for An. darlingi control in this locality has resulted in a natural resistance to this insecticide. In addition, DDT resistance is still present in this population, although this insecticide has not been used in Colombia since 1992. Increased metabolism through MFO and NSE may be involved in cross-resistance between lambda-cyhalothrin and DDT, although kdr-type nerve insensitivity cannot be discarded as a possible hypothesis. Additional research, including development of a kdr specific assay for An. darlingi should be conducted in future studies. Our data demonstrates the urgent need to develop local insecticide resistance management and surveillance programs throughout Colombia.

  2. Evaluation of larvicidal activity of the methanolic extracts of Piper alatabaccum branches and P. tuberculatum leaves and compounds isolated against Anopheles darlingi

    Directory of Open Access Journals (Sweden)

    Frances T. T. Trindade

    2012-10-01

    Full Text Available Piper is a notable genus among Piperaceae due to their secondary metabolites such as lignans, amides, esters and long chain fatty acids used as anti-herbivore defenses with comparable effects of pyrethroids, that holds a promise in insect control, including malaria vectors such as Anopheles darlingi, the main vector in the North of Brazil. Methanolic extracts of Piper tuberculatum Jacq., Piperaceae, and P. alatabaccum Trel. & Yunck., Piperaceae, and some isolated compounds, i.e, 3,4,5-trimetoxy-dihydrocinamic acid, dihydropiplartine; piplartine, piplartine-dihydropiplartine and 5,5',7-trimetoxy-3',4'-metilenodioxiflavone were tested as larvicides against A. darlingi. The Lethal Concentrations (LC50 and LC90 of methanolic extracts were 194 and 333 ppm for P. tuberculatum and 235 and 401 ppm for P. alatabacum, respectively. Isolated compounds had lower LC values, e.g. the LC50 and LC90 of the piplartine-dihidropiplartine isolated from both plant species was 40 and 79 ppm, respectively.

  3. A Study on the Bionomics of Anopheles darlingi Root (Diptera: Culicidae) in Belize, Central America

    Science.gov (United States)

    2004-03-01

    shown). (B) A supervised classification of the image was used to quantify the difference in pixel counts of broadleaf/ palm forest (green), pasture...flow by bulldozed forest debris; contamination of freshwater by agrochemicals; and eutrophication of waterways by discharge from food and sugar...conditions of high populations and/or malaria transmission, the application of oils to potential breeding habitats surrounding homes will be performed

  4. Malaria in Suriname: a new era : impact of modified intervention strategies on Anopheles darlingi populations and malaria incidence

    NARCIS (Netherlands)

    Hiwat-van Laar, H.

    2011-01-01

    Malaria is an infectious disease caused by Plasmodiumblood parasites which live inside the human host and are spread by Anopheles mosquitoes.Every year an estimated 225 million new cases and near 800.000 malaria deaths are reported. Control of the disease is a formidable task involving all three liv

  5. ECOLOGICAL CHANGE AS A FACTOR IN RENEWED MALARIA TRANSMISSION IN AN ERADICATED AREA. A LOCALIZED OUTBREAK OF A. AQUASALIS-TRANSMITTED MALARIA ON THE DEMERARA RIVER ESTUARY, BRITISH GUIANA, IN THE FIFTEENTH YEAR OF A. DARLINGI AND MALARIA ERADICATION.

    Science.gov (United States)

    GIGLIOLI, G

    1963-01-01

    In British Guiana, the successful eradication of Anopheles darlingi and malaria from the coastal areas has caused a very rapid increase in the population and has favoured a considerable social and economic improvement and expansion of both agriculture and industry. Housing and industrial developments and the constantly expanding rice cultivation have taken over most of the accessible pasture-lands, displacing the livestock which previously abounded around villages and settlements. Mechanization on the roads and in the fields increases daily, and the horse, the mule, the donkey and the ploughing oxen are gradually becoming obsolete.In some areas these changes have already caused such an upset in the balance between the human and the livestock population that A. aquasalis, a very abundant species all along the coast, but until recently entirely "fixed" by the livestock population, is now shifting its attention from livestock to man. On the Demerara river estuary, an area where malaria transmission was interrupted sixteen years ago and where eradication has been continually maintained, this mosquito has been responsible for a sharp, but localized, outbreak of P. vivax malaria. An entirely new epidemiological problem thus presents itself.Environmental changes, introduced and fostered by successful malaria eradication, may thus cause an anopheline species, potentially capable of malaria transmission, but originally inactive and harmless as a vector, to alter its feeding habits and thereby renew transmission. The immediate and long-term significance of some secondary and potential vectors may therefore require renewed evaluation in the planning of malaria eradication campaigns.

  6. Comparative Vector Bionomics and Morphometrics of Two Genetically Distinct Field Populations of Anopheles darlingi Root from Belize, Central America and Zungarococha, Peru, South America

    Science.gov (United States)

    2014-01-31

    Sociedade Brasileira de Medicina Tropical 46: 172-7 64. Garrett-Jones C. 1964. The Human Blood Index of Malaria Vectors in Relation to...Revista da Sociedade Brasileira de Medicina Tropical 24: 13-20 94. Klingenberg CP. 2002. Morphometrics and the role of the phenotype in studies of the...Anopheles species from Porto Velho, Rondonia state, western Amazon, Brazil. Revista do Instituto de Medicina Tropical de Sao Paulo 54:331-5 125. Morales

  7. Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV) in mosquitoes.

    Science.gov (United States)

    Barik, Tapan K; Suzuki, Yasutsugu; Rasgon, Jason L

    2016-01-01

    Anopheles gambiae densovirus (AgDNV) is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae, the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP) reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae.

  8. Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV in mosquitoes

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    Tapan K. Barik

    2016-11-01

    Full Text Available Anopheles gambiae densovirus (AgDNV is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae, the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae.

  9. Biting behavior of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil

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    Terry A. Klein

    1991-03-01

    Full Text Available Mosquito collections were made in and near Costa Marques, Rondonia, Brazil, to determine anopheline anthropophilic/zoophilic behavior. Collections from a non-illuminated, bovine-baited trap and indoor and outdoor human-bait collections were compared. Anopheles darlingi and Anopheles deaneorum were more anthropophilic than the other anophelines collected. The remainder of the Anopheles species were collected much morefrequently in bovine-baited traps than in human-bait collections. Anopheles darlingi and An. deaneorum were more frequently collected inside houses than the other anopheline species. But, when collections were made in a house with numerous openings in the walls, there were few differences in the percentages of each species biting man indoors versus outdoors. Anopheles darlingi was the predominant mosquito collected, both inside and outside houses, and had the strongest anthropophilic feeding behavior of the anophelines present.Para determinar o comportamento antropofilico e zoofilico dos anofelinos, foram capturados mosquitos na periferia e na zona urbana de Costa Marques, Rondônia, Brasil. Foram comparadas as capturas feitas à noite, com iscas bovinas e humanas, dentro efora de casa. O Anopheles darlingi e o Anopheles deaneorumforam mais antropojilicos do que os outros anofelinos capturados. O restante das espécies anofelinas foi capturado mais freqüentemente nas iscas bovinas do que nas humanas. Anopheles darlingi e Anopheles deaneorumforam capturados dentro de casa com mais freqüência do que as outras espécies anofelinas. Porém, quando a captura foi feita em casas com muitas aberturas nas paredes houve pouca diferença nas porcentagens de cada espécie sugadora de humanos dentro efora de casa. Anopheles darlingi foi o mosquito capturado com mais freqüência, dentro e fora de casa, e apresentava maior antropofilia em relação aos outros anofelinos presentes.

  10. [The Anopheles fauna and the transmission of human malaria in Kinshasa (Zaire)].

    Science.gov (United States)

    Karch, S; Asidi, N; Manzambi, Z M; Salaun, J J

    1992-01-01

    A longitudinal epidemiological study of malaria and its vectors was conducted in Kinshasa. 264 night-bite collections on human bait (1,056 man nights) and 384 collections of the house-resting fauna were carried out from April 1989 to October 1990. The anophelian fauna was identified and inventoried, 7 Anopheles species were found: Anopheles gambiae, An. funestus, An. paludis, An. hancocki, An. counstani, An. brunnipes, and An. nili. A single species, An. gambiae s. l. is responsible for the transmission of malaria, it represents 93.27% of the anopheline fauna. The average number of anophele bites man day was 16.28 bites/man/night, it varied between 1 b/m/n in urban area to 26.05 b/m/n in semi-rural area. The average of the sporozoite index for An. gambiae was 3.3%, but it varied from 0% in the urban area to 6.52% in the semi-rural area. The entomological inoculation rate (h) was 197 infective bites per year. This rate fluctuated from 1 infective bite each 128 nights in urban area to 1.7 infective night-bite in semi-rural area. Other epidemiological index were also determined: the level of daily survival rate (p = 8.75 days), the vectorial capacity of 17.97 and the Macdonald's stability 3.5 bites on man taken by a vector during its entire lifetime.

  11. Behavioral patterns, parity rate and natural infection analysis in anopheline species involved in the transmission of malaria in the northeastern Brazilian Amazon region.

    Science.gov (United States)

    Barbosa, Ledayane Mayana Costa; Souto, Raimundo Nonato Picanço; Dos Anjos Ferreira, Ricardo Marcelo; Scarpassa, Vera Margarete

    2016-12-01

    The characterization of behavioral patterns allows a better understanding of the transmission dynamics and the design of more effective malaria vector control strategies. This study analyzed the behavioral patterns of the Anopheles species of the Coração district situated in the northeast of the Brazilian Amazon region. The behavioral patterns of the anopheline species were measured based on the 36 collection sites of this district from December 2010 to November 2011. Collections of four hours for three consecutive nights each month and four 12-h collections, comprising two in the rainy season and two in the dry season, were performed. Furthermore, to infer the anthropophily and zoophily indexes, four additional four-hour collections were performed. The samples were also evaluated for parity rate and natural infectivity for Plasmodium spp. A total of 1689 anophelines were captured, comprising of nine species and two subgenera (Nyssorhynchus - six species, and Anopheles - three species). Anopheles darlingi was the most abundant and widely distributed species in the area, followed by A. braziliensis and A.marajoara. Anopheles darlingi and A. marajoara were the only species present in the four collections of 12-h, but only A. darlingi showed activity throughout night. Anopheles darlingi was the most anthropophilic species (AI=0.40), but the zoophily index was higher (ZI=0.60), revealing an eclectic and opportunistic behavior. Of the six most frequent species, A. nuneztovari s.l. was the most zoophilic species (ZI=1.00). All captured species showed predominance towards biting in outdoor environments. Anopheles darlingi and A. braziliensis showed multimodal biting peaks, whereas A. marajoara revealed a stable pattern, with the biting peak after sunset. Using the PCR technique, no anopheline was found infected with the malaria parasite. Since A. darlingi and A. marajoara are recognized as important vectors in this region, the district of Coração may be considered as

  12. Malaria vectors in the Brazilian Amazon: Anopheles of the subgenus Nyssorhynchus Anopheles do subgênero Nyssorhynchus, vetores da malária na Amazônia brasileira

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    Wanderli Pedro TADEI

    2000-04-01

    Full Text Available Various species of Anopheles (Nyssorhynchus were studied in the Amazon with the objective of determining their importance as malaria vectors. Of the 33 known Anopheles species occurring in the Amazon, only 9 were found to be infected with Plasmodium. The different species of this subgenus varied both in diversity and density in the collection areas. The populations showed a tendency towards lower density and diversity in virgin forest than in areas modified by human intervention. The principal vector, An. darlingi, is anthropophilic with a continuous activity cycle lasting the entire night but peaking at sunset and sunrise. These species (Nyssorhynchus are peridomiciliary, entering houses to feed on blood and immediately leaving to settle on nearby vegetation. Anopheles nuneztovari proved to be zoophilic, crepuscular and peridomiciliary. These habits may change depending on a series of external factors, especially those related to human activity. There is a possibility that sibling species exist in the study area and they are being studied with reference to An. darlingi, An. albitarsis and An. nuneztovari. The present results do not suggest the existence of subpopulations of An. darlingi in the Brazilian Amazon.Várias espécies de Anopheles (Nyssorhynchus foram estudadas na Amazônia a fim de se determinar sua importância na transmissão da malária. Das 33 espécies de Anopheles de ocorrência conhecida na Amazônia, apenas 8 foram encontradas infectadas por Plasmodium. O principal vetor, An. darlingi, é antropofílico com um ciclo contínuo de atividade que dura a noite inteira mas que tem picos ao anoitecer e ao amanhecer. As diferentes espécies desse subgênero variaram tanto em diversidade como em densidade nas áreas de coleta. A população de anofelinos apresentou tendências de menor densidade e diversidade em florestas virgens do que em áreas que sofreram intervenção humana. Essas espécies (Nyssorhynchus são peridomiciliares

  13. On the use of classic epidemiological formulae for estimating the intensity of endemic malaria transmission by vectors in the Amazon.

    Science.gov (United States)

    Barros, F S M; Tadei, W P; Arruda, M E; Honório, Nildimar A

    2012-10-01

    Although various reports have described entomological inoculation rates of malaria vector species, most were limited to providing descriptive field data. Here, we report biting rates and survival data for two important malaria vectors in the Amazon, Anopheles darlingi (Root) and Anopheles albitarsis E (Lynch-Arribalzaga) (Diptera: Culicidae), in the state of Roraima, Brazil. We calculated theoretical sporozoite infection rates and critical vector biting rates for these species during 1 year, comprising six bimestrial collections. Anopheles darlingi had higher sporozoite rates and lower critical biting rates, indicating that it would be the more efficient vector at the beginning of epidemic malaria transmission. Our data, together with compiled information from the literature in the Amazon, suggest that epidemic malaria transmission may be initiated by the primary vector, such as A. darlingi, while secondary vectors, such as A. albitarsis E, may only become epidemiologically important when there is an increase in the prevalence of human malaria. We propose that mathematical modeling may be able to quantify the relative importance of secondary vector species in malaria epidemiology.

  14. An overview of malaria transmission from the perspective of Amazon Anopheles vectors

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    Paulo FP Pimenta

    2015-02-01

    Full Text Available In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.

  15. Peculiar liquid-feeding and pathogen transmission behavior of Aedes togoi and comparison with Anopheles sinensis

    Science.gov (United States)

    Lee, Sang Joon; Kang, Dooho; Lee, Seung Chul; Ha, Young-Ran

    2016-02-01

    Female mosquitoes transmit various diseases as vectors during liquid-feeding. Identifying the determinants of vector efficiency is a major scientific challenge in establishing strategies against these diseases. Infection rate and transmission efficiency are interconnected with the mosquito-induced liquid-feeding flow as main indexes of vector efficiency. However, the relationship between liquid-feeding characteristics and pathogen remains poorly understood. The liquid-feeding behavior of Aedes togoi and Anopheles sinensis was comparatively investigated in conjunction with vector efficiency via micro-particle image velocimetry. The flow rates and ratio of the ejection volume of Aedes togoi were markedly higher than those of Anophels sinensis. These differences would influence pathogen re-ingestion. Wall shear stresses of these mosquito species were also clearly discriminatory affecting the infective rates of vector-borne diseases. The variations in volume of two pump chambers and diameter of proboscis of these mosquito species were compared to determine the differences in the liquid-feeding process. Liquid-feeding characteristics influence vector efficiency; hence, this study can elucidate the vector efficiency of mosquitoes and the vector-pathogen interactions and contribute to the development of strategies against vector-borne diseases.

  16. Description of Anopheles gabonensis, a new species potentially involved in rodent malaria transmission in Gabon, Central Africa.

    Science.gov (United States)

    Rahola, Nil; Makanga, Boris; Yangari, Patrick; Jiolle, Davy; Fontenille, Didier; Renaud, François; Ollomo, Benjamin; Ayala, Diego; Prugnolle, Franck; Paupy, Christophe

    2014-12-01

    The genus Anopheles includes mosquito vectors of human malaria and arboviruses. In sub-Saharan Africa, the anopheline fauna is rich of nearly 150 species, few of which are anthropophilic and capable of transmitting pathogens to humans. Some of the remaining species are found in forests far from human environments and are vectors of wildlife pathogens. The diversity and the biology of these species have yet to be fully described. As a contribution to furthering knowledge of sylvan Anophelinae, using morphological and molecular tools we describe a new Anopheles species collected in Gabon (Central Africa), which we have named Anopheles gabonensis n. sp. We also molecularly screened this species to detect infections by Plasmodium parasites. The results showed the species to have been infected by Plasmodium vinckei, a rodent parasite. We discuss the role of An. gabonensis n. sp. in the transmission of P. vinckei in the rainforest areas of Central Africa and its potential to transfer pathogens to humans.

  17. Characterization of Plasmodium developmental transcriptomes in Anopheles gambiae midgut reveals novel regulators of malaria transmission.

    Science.gov (United States)

    Akinosoglou, Karolina A; Bushell, Ellen S C; Ukegbu, Chiamaka Valerie; Schlegelmilch, Timm; Cho, Jee-Sun; Redmond, Seth; Sala, Katarzyna; Christophides, George K; Vlachou, Dina

    2015-02-01

    The passage through the mosquito is a major bottleneck for malaria parasite populations and a target of interventions aiming to block disease transmission. Here, we used DNA microarrays to profile the developmental transcriptomes of the rodent malaria parasite Plasmodium berghei in vivo, in the midgut of Anopheles gambiae mosquitoes, from parasite stages in the midgut blood bolus to sporulating oocysts on the basal gut wall. Data analysis identified several distinct transcriptional programmes encompassing genes putatively involved in developmental processes or in interactions with the mosquito. At least two of these programmes are associated with the ookinete development that is linked to mosquito midgut invasion and establishment of infection. Targeted disruption by homologous recombination of two of these genes resulted in mutant parasites exhibiting notable infection phenotypes. GAMER encodes a short polypeptide with granular localization in the gametocyte cytoplasm and shows a highly penetrant loss-of-function phenotype manifested as greatly reduced ookinete numbers, linked to impaired male gamete release. HADO encodes a putative magnesium phosphatase with distinctive cortical localization along the concave ookinete periphery. Disruption of HADO compromises ookinete development leading to significant reduction of oocyst numbers. Our data provide important insights into the molecular framework underpinning Plasmodium development in the mosquito and identifies two genes with important functions at initial stages of parasite development in the mosquito midgut.

  18. Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.

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    Weidong Gu

    Full Text Available An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595, lower survival rates (0.72 vs. 0.93, and prolonged gonotrophic cycles (3.33 vs. 2.36 days. The estimated number of females older than the extrinsic incubation period of malaria (10 days in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73% than in the sugar-poor site (48%. In contrast, plant tissue feeding (poor quality sugar source in the sugar-rich habitat was much less (0.3% than in the sugar-poor site (30%. More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens.

  19. Biology, distribution and control of Anopheles (Cellia) minimus in the context of malaria transmission in northeastern India.

    Science.gov (United States)

    Dev, Vas; Manguin, Sylvie

    2016-11-15

    Among six dominant mosquito vector species involved in malaria transmission in India, Anopheles minimus is a major species in northeast India and held responsible for focal disease outbreaks characterized by high-rise of Plasmodium falciparum infections and attributable death cases. It has been now genetically characterized that among the three-member species of the Minimus Complex spread in Asia, An. minimus (former species A) is prevalent in India including northeastern states and east-central state of Odisha. It is recorded in all seasons and accounts for perennial transmission evidenced by records of sporozoite infections. This species is highly anthropophilic, and largely endophilic and endophagic, recorded breeding throughout the year in slow flowing seepage water streams. The populations of An. minimus in India are reported to be highly diverse indicating population expansion with obvious implications for judicious application of vector control interventions. Given the rapid ecological changes due to deforestation, population migration and expansion and developmental activities, there is scope for further research on the existence of potential additional sibling species within the An. minimus complex and bionomics studies on a large geographical scale for species sanitation. For control of vector populations, DDT continues to be applied on account of retaining susceptibility status even after decades of residual spraying. Anopheles minimus is a highly adaptive species and requires continuous and sustained efforts for its effective control to check transmission and spread of drug-resistant malaria. Anopheles minimus populations are reportedly diminishing in northeastern India whereas it has staged comeback in east-central State of Odisha after decades of disappearance with its eco-biological characteristics intact. It is the high time to siege the opportunity for strengthening interventions against this species for its population diminution to sub

  20. Spatial distribution, blood feeding pattern, and role of Anopheles funestus complex in malaria transmission in central Kenya.

    Science.gov (United States)

    Muturi, Ephantus J; Kamau, Luna; Jacob, Benjamin G; Muriu, Simon; Mbogo, Charles M; Shililu, Josephat; Githure, John; Novak, Robert J

    2009-10-01

    Studies were conducted to determine the role of sibling species of Anopheles funestus complex in malaria transmission in three agro-ecosystems in central Kenya. Mosquitoes were sampled indoors and outdoors, and rDNA PCR was successfully used to identify 340 specimens. Anopheles parensis (91.8%), A. funestus (6.8%), and Anopheles leesoni (1.5%) were the three sibling species identified. A. parensis was the dominant species at all study sites, while 22 of 23 A. funestus were collected in the non-irrigated study site. None of the 362 specimens tested was positive for Plasmodium falciparum circumsporozoite proteins by enzyme-linked immunosorbent assay. The most common blood-meal sources (mixed blood meals included) for A. parensis were goat (54.0%), human (47.6%), and bovine (39.7%), while the few A. funestus s.s. samples had fed mostly on humans. The human blood index (HBI) for A. parensis (mixed blood meals included) in the non-irrigated agro-ecosystem was 0.93 and significantly higher than 0.33 in planned rice agro-ecosystem. The few samples of A. funestus s.s. and A. funestus s.l. also showed a trend of higher HBI in the non-irrigated agro-ecosystem. We conclude that agricultural practices have significant influence on distribution and blood feeding behavior of A. funestus complex. Although none of the species was implicated with malaria transmission, these results may partly explain why non-irrigated agro-ecosystems are associated with higher risk of malaria transmission by this species compared to irrigated agro-ecosystems.

  1. [Malaria mosquitoes (Diptera, Culicidae, Anopheles) of North Tajikistan, their ecology, and role in the transmission of malaria pathogens].

    Science.gov (United States)

    Kadamov, D S; Zvantseva, A B; Karimov, S S; Gordeev, M I; Goriacheva, I I; Ezhov, M N; Tadzhiboev, A

    2012-01-01

    Five species of malaria mosquitoes: An. artemievi, An. claviger, An. hyrcanus, An. superpictus, and An. pulcherrimus were found in North Tajikistan in 2006 - 2007. Species affiliation was identified according to the morphological signs of their larvae and imagoes, and by using the polymerase chain reaction-restriction fragment length polymorphism analysis. There was a larger number of An. hyrcanus (34%), An. artemievi (29%), and An. pulcherrimus (24%) and a smaller number of An. superpictus (11%); and An. claviger was few (2%). The hatching sites of the above species and the preferred types of their day refuges were found. The intensity of attack of different Anopheles species on humans and animals was studied. Among the North Tajikistan malaria mosquitoes, An. pulcherrimus and An. superpictus are of the greatest epidemiological importance as vehicles for transmission of malaria pathogens. An. artemievi and An. hyrcanus are minor vehicles. At present, An. claviger is of no epidemiological significance in transmitting malaria in North Tajikistan.

  2. Recombinant Pvs48/45 antigen expressed in E. coli generates antibodies that block malaria transmission in Anopheles albimanus mosquitoes.

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    Myriam Arévalo-Herrera

    Full Text Available Transmission of malaria parasites from humans to Anopheles mosquitoes can be inhibited by specific antibodies elicited during malaria infection, which target surface Plasmodium gametocyte/gamete proteins. Some of these proteins may have potential for vaccine development. Pvs48/45 is a P. vivax gametocyte surface antigen orthologous to Pfs48/45, which may play a role during parasite fertilization and thus has potential for transmission blocking (TB activity. Here we describe the expression of a recombinant Pvs48/45 protein expressed in Escherichia coli as a ∼60kDa construct which we tested for antigenicity using human sera and for its immunogenicity and transmission blocking activity of specific anti-mouse and anti-monkey Pvs48/45 antibodies. The protein reacted with sera of individuals from malaria-endemic areas and in addition induced specific IgG antibody responses in BALB/c mice and Aotus l. griseimembra monkeys. Sera from both immunized animal species recognized native P. vivax protein in Western blot (WB and immunofluorescence assays. Moreover, sera from immunized mice and monkeys produced significant inhibition of parasite transmission to An. Albimanus mosquitoes as shown by membrane feeding assays. Results indicate the presence of reactive epitopes in the Pvs48/45 recombinant product that induce antibodies with TB activity. Further testing of this protein is ongoing to determine its vaccine potential.

  3. Vector bionomics and malaria transmission in the Upper Orinoco River, Southern Venezuela

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    Magda Magris

    2007-06-01

    Full Text Available A longitudinal epidemiological and entomological study was carried out in Ocamo, Upper Orinoco River, between January 1994 and February 1995 to understand the dynamics of malaria transmission in this area. Malaria transmission occurs throughout the year with a peak in June at the beginning of the rainy season. The Annual Parasite Index was 1,279 per 1,000 populations at risk. Plasmodium falciparum infections accounted for 64% of all infections, P. vivax for 28%, and P. malariae for 4%. Mixed P. falciparum/P. vivax infections were diagnosed in 15 people representing 4% of total cases. Children under 10 years accounted for 58% of the cases; the risk for malaria in this age group was 77% higher than for those in the greater than 50 years age group. Anopheles darlingi was the predominant anopheline species landing on humans indoors with a biting peak between midnight and dawn. A significant positive correlation was found between malaria monthly incidence and mean number of An. darlingi caught. There was not a significant relationship between mean number of An. darlingi and rainfall or between incidence and rainfall. A total of 7295 anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite (CS protein. Only An. darlingi (55 was positive for CS proteins of P. falciparum (0.42%, P. malariae (0.25%, and P. vivax-247 (0.1%. The overall estimated entomological inoculation rate was 129 positive bites/person/year. The present study was the first longitudinal entomological and epidemiological study conducted in this area and set up the basic ground for subsequent intervention with insecticide-treated nets.

  4. Incrimination of Anopheles (Nyssorhynchus rangeli and An. (Nys. oswaldoi as natural vectors of Plasmodium vivax in Southern Colombia

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    Martha L Quiñones

    2006-09-01

    Full Text Available Malaria transmission in the Southern Colombian state of Putumayo continues despite the absence of traditional vector species, except for the presence of Anopheles darlingi near the southeastern border with the state of Amazonas. In order to facilitate malaria vector incrimination in Putumayo, 2445 morphologically identified Anopheles females were tested for natural infection of Plasmodium vivax by ELISA. Specimens tested included An. apicimacula (n = 2, An. benarrochi B (n = 1617, An. darlingi (n = 29, An. mattogrossensis (n = 7, An. neomaculipalpus (n = 7, An. oswaldoi (n = 362, An. peryassui (n = 1, An. punctimacula (n = 1, An. rangeli (n = 413, and An. triannulatus (n = 6. Despite being overwhelmingly the most anthropophilic species in the region and comprising 66.1% of the mosquitoes tested, An. benarrochi B was not shown to be a vector. Thirty-five An. rangeli and one An. oswaldoi were naturally infected with P. vivax VK210. Sequence data were generated for the nuclear second internal transcriber space region of 31 of these 36 vivax positive mosquitoes (86.1% to confirm their morphological identification. An. oswaldoi is known to be a species complex in Latin America, but its internal taxonomy remains unresolved. Herein we show that the An. oswaldoi found in the state of Putumayo is genetically similar to specimens from the state of Amapá in Brazil and from the Ocama region in the state of Amazonas in Venezuela, and that this form harbors natural infections of P. vivax. That An. rangeli and this member of the An. oswaldoi complex are incriminated as malaria vectors in Putumayo, is a novel finding of significance for malaria control in Southern Colombia, and possibly in other areas of Latin America.

  5. Reduction of malaria transmission to Anopheles mosquitoes with a six-dose regimen of co-artemether.

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    Colin J Sutherland

    2005-04-01

    Full Text Available BACKGROUND: Resistance of malaria parasites to chloroquine (CQ and sulphadoxine-pyrimethamine (SP is increasing in prevalence in Africa. Combination therapy can both improve treatment and provide important public health benefits if it curbs the spread of parasites harbouring resistance genes. Thus, drug combinations must be identified which minimise gametocyte emergence in treated cases, and so prevent selective transmission of parasites resistant to any of the partner drugs. METHODS AND FINDINGS: In a randomised controlled trial, 497 children with uncomplicated falciparum malaria were treated with CQ and SP (three doses and one dose respectively; n = 91, or six doses of artemether in fixed combination with lumefantrine (co-artemether [Coartem, Riamet] (n = 406. Carriage rates of Plasmodium falciparum gametocytes and trophozoites were measured 7, 14, and 28 d after treatment. The infectiousness of venous blood from 29 children carrying P. falciparum gametocytes 7 d after treatment was tested by membrane-feeding of Anopheles mosquitoes. Children treated with co-artemether were significantly less likely to carry gametocytes within the 4 weeks following treatment than those receiving CQ/SP (30 of 378 [7.94%] versus 42 of 86 [48.8%]; p < 0.0001. Carriers in the co-artemether group harboured gametocytes at significantly lower densities, for shorter periods (0.3 d versus 4.2 d; p < 0.0001 and were less infectious to mosquitoes at day 7 (p < 0.001 than carriers who had received CQ/SP. CONCLUSIONS: Co-artemether is highly effective at preventing post-treatment transmission of P. falciparum. Our results suggest that co-artemether has specific activity against immature sequestered gametocytes, and has the capacity to minimise transmission of drug-resistant parasites.

  6. 4-(1H)-Quinolones and 1,2,3,4-Tetrahydroacridin-9(10H)-ones prevent the transmission of Plasmodium falciparum to Anopheles freeborni.

    Science.gov (United States)

    Sáenz, Fabián E; Lacrue, Alexis N; Cross, R Matthew; Maignan, Jordany R; Udenze, Kenneth O; Manetsch, Roman; Kyle, Dennis E

    2013-12-01

    Malaria kills approximately 1 million people a year, mainly in sub-Saharan Africa. Essential steps in the life cycle of the parasite are the development of gametocytes, as well as the formation of oocysts and sporozoites, in the Anopheles mosquito vector. Preventing transmission of malaria through the mosquito is necessary for the control of the disease; nevertheless, the vast majority of drugs in use act primarily against the blood stages. The study described herein focuses on the assessment of the transmission-blocking activities of potent antierythrocytic stage agents derived from the 4(1H)-quinolone scaffold. In particular, three 3-alkyl- or 3-phenyl-4(1H)-quinolones (P4Qs), one 7-(2-phenoxyethoxy)-4(1H)-quinolone (PEQ), and one 1,2,3,4-tetrahydroacridin-9(10H)-one (THA) were assessed for their transmission-blocking activity against the mosquito stages of the human malaria parasite (Plasmodium falciparum) and the rodent parasite (P. berghei). Results showed that all of the experimental compounds reduced or prevented the exflagellation of male gametocytes and, more importantly, prevented parasite transmission to the mosquito vector. Additionally, treatment with ICI 56,780 reduced the number of sporozoites that reached the Anopheles salivary glands. These findings suggest that 4(1H)-quinolones, which have activity against the blood stages, can also prevent the transmission of Plasmodium to the mosquito and, hence, are potentially important drug candidates to eradicate malaria.

  7. Isoenzymatic variability among five Anopheles species belonging to the Nyssorhynchus and Anopheles subgenera of the Amazon region, Brazil

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    Joselita Maria Mendes dos Santos

    2003-03-01

    Full Text Available An isoenzymatic comparative analysis of the variability and genetics differentiation among Anopheles species was done in populations of An. (Nys. intermedius and An. (Ano. mattogrossensis of the Anopheles subgenus, and of An. darlingi, An. albitarsis and An. triannulatus of the Nyssorhynchus subgenus, with the aim of detecting differences between both subgenera and of estimating the degree of genetic intere specific divergence. Samples from Macapá, State of Amapá and Janauari Lake, near Manaus, State of Amazonas, were analyzed for eight isoenzymatic loci. Analysis revealed differences in the average number of alleles per locus (1.6-2.3 and heterozygosity (0.060-0.284. However, the proportion of polymorphic loci was the same for An. (Nys. darlingi, An. (Nys. triannulatus and An. (Ano. mattogrossensis (50%, but differed for An. (Nys. albitarsis (62.5% and An. (Ano. intermedius (25%. Only the IDH1 (P > 0.5 locus in all species studied was in Hardy-Weinberg equilibrium. The fixation index demonstrated elevated genetic structuring among species, based on values of Fst = 0.644 and genetic distance (0.344-0.989. Genetic difference was higher between An. (Nys. triannulatus and An. (Ano. intermedius (0.989 and smaller between An. (Nys. albitarsis sensu lato and An. (Nys. darlingi (0.344. The data show interspecific genetic divergence which differs from the phylogenetic hypothesis based on morphological characters.

  8. Mathematical evaluation of community level impact of combining bed nets and indoor residual spraying upon malaria transmission in areas where the main vectors are Anopheles arabiensis mosquitoes

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    Okumu Fredros O

    2013-01-01

    Full Text Available Abstract Background Indoor residual insecticide spraying (IRS and long-lasting insecticide treated nets (LLINs are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. Methods A deterministic model of mosquito life cycle processes was adapted to allow parameterization with results from experimental hut trials of various combinations of untreated nets or LLINs (Olyset®, PermaNet 2.0®, Icon Life® nets with IRS (pirimiphos methyl, lambda cyhalothrin, DDT, in a setting where vector populations are dominated by Anopheles arabiensis, so that community level impact upon malaria transmission at high coverage could be predicted. Results Intact untreated nets alone provide equivalent personal protection to all three LLINs. Relative to IRS plus untreated nets, community level protection is slightly higher when Olyset® or PermaNet 2.0® nets are added onto IRS with pirimiphos methyl or lambda cyhalothrin but not DDT, and when Icon Life® nets supplement any of the IRS insecticides. Adding IRS onto any net modestly enhances communal protection when pirimiphos methyl is sprayed, while spraying lambda cyhalothrin enhances protection for untreated nets but not LLINs. Addition of DDT reduces communal protection when added to LLINs. Conclusions Where transmission is mediated primarily by An. arabiensis, adding IRS to high LLIN coverage provides only modest incremental benefit (e.g. when an organophosphate like pirimiphos methyl is used, but can be redundant (e.g. when a pyrethroid like lambda cyhalothin is used or even regressive (e.g. when DDT is used for the IRS. Relative to IRS plus untreated nets, supplementing IRS with LLINs will only modestly improve community protection. Beyond the physical protection that intact nets provide, additional protection against transmission by An. arabiensis conferred by insecticides will be remarkably small, regardless of

  9. Seasonal population changes and malaria transmission potential of Anopheles pharoensis and the minor anophelines in Mwea Irrigation Scheme, Kenya.

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    Mukiama, T K; Mwangi, R W

    1989-05-01

    A study in 1984 and 1985 showed that Anopheles gambiae s.l. and An. pharoensis were the major anophelines in Mwea Irrigation Scheme, Kenya, constituting 83.86% and 15.69% of the catch respectively. Four minor species made up the remaining 0.45%. The irrigation phase of the rice cultivation cycle in August, which linked the flooding effects of the two rainy seasons, resulted in major population increases of An. pharoensis and enabled continuous breeding for up to 9 months per year. The average of mean monthly proportions of unfed, bloodfed, and gravid females was 26.6, 58.8, and 14.6% respectively. The Plasmodium falciparum sporozoite rates for An. pharoensis were 1.3% by ELISA and 0.68% by dissection, while those for An. funestus were 1.7% by ELISA and 1.25% by dissection. An. pharoensis can contribute to the epidemiology of Malaria in the Mwea area.

  10. Determinants of Anopheles seasonal distribution patterns across a forest to periurban gradient near Iquitos, Peru.

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    Reinbold-Wasson, Drew D; Sardelis, Michael R; Jones, James W; Watts, Douglas M; Fernandez, Roberto; Carbajal, Faustino; Pecor, James E; Calampa, Carlos; Klein, Terry A; Turell, Michael J

    2012-03-01

    As part of a field ecology study of arbovirus and malaria activity in the Amazon Basin, Loreto Department, Peru, we collected mosquitoes landing on humans at a forest site and inside and outside of residences and military barracks at periurban, rural, and village sites. We collected 11 Anopheles spp. from these four sites. An. darlingi, the principal malaria vector in the region, accounted for 98.7% of all Anopheles spp. collected at Puerto Almendra. Peaks in landing activity occurred during the December and April collection periods. However, the percent of sporozoite-positive Anopheles spp. was highest 1-2 months later, when landing activity decreased to approximately 10% of the peak activity periods. At all sites, peak landing activity occurred about 2 hours after sunset. These data provide a better understanding of the taxonomy, population density, and seasonal and habitat distribution of potential malaria vectors within the Amazon Basin region.

  11. A spatial individual-based model predicting a great impact of copious sugar sources and resting sites on survival of Anopheles gambiae and malaria parasite transmission

    Science.gov (United States)

    Zhu, Lin; Qualls, Whitney A.; Marshall, John M; Arheart, Kris L.; DeAngelis, Don; McManus, John W.; Traore, Sekou F.; Doumbia, Seydou; Schlein, Yosef; Muller, Gunter C.; Beier, John C.

    2015-01-01

    BackgroundAgent-based modelling (ABM) has been used to simulate mosquito life cycles and to evaluate vector control applications. However, most models lack sugar-feeding and resting behaviours or are based on mathematical equations lacking individual level randomness and spatial components of mosquito life. Here, a spatial individual-based model (IBM) incorporating sugar-feeding and resting behaviours of the malaria vector Anopheles gambiae was developed to estimate the impact of environmental sugar sources and resting sites on survival and biting behaviour.MethodsA spatial IBM containing An. gambiae mosquitoes and humans, as well as the village environment of houses, sugar sources, resting sites and larval habitat sites was developed. Anopheles gambiae behaviour rules were attributed at each step of the IBM: resting, host seeking, sugar feeding and breeding. Each step represented one second of time, and each simulation was set to run for 60 days and repeated 50 times. Scenarios of different densities and spatial distributions of sugar sources and outdoor resting sites were simulated and compared.ResultsWhen the number of natural sugar sources was increased from 0 to 100 while the number of resting sites was held constant, mean daily survival rate increased from 2.5% to 85.1% for males and from 2.5% to 94.5% for females, mean human biting rate increased from 0 to 0.94 bites per human per day, and mean daily abundance increased from 1 to 477 for males and from 1 to 1,428 for females. When the number of outdoor resting sites was increased from 0 to 50 while the number of sugar sources was held constant, mean daily survival rate increased from 77.3% to 84.3% for males and from 86.7% to 93.9% for females, mean human biting rate increased from 0 to 0.52 bites per human per day, and mean daily abundance increased from 62 to 349 for males and from 257 to 1120 for females. All increases were significant (P parasite transmission.

  12. Bioefficacy of long-lasting insecticidal nets against pyrethroid-resistant populations of Anopheles gambiae s.s. from different malaria transmission zones in Uganda

    OpenAIRE

    Okia, Michael; Ndyomugyenyi, Richard; Kirunda, James; Byaruhanga, Anatol; Adibaku, Seraphine; Lwamafa, Denis K; Kironde, Fred

    2013-01-01

    Background There are major concerns over sustaining the efficacy of current malaria vector control interventions given the rapid spread of resistance, particularly to pyrethroids. This study assessed the bioefficacy of five WHO-recommended long-lasting insecticidal nets (LLINs) against pyrethroid-resistant Anopheles gambiae field populations from Uganda. Methods Adult An. gambiae from Lira, Tororo, Wakiso and Kanungu districts were exposed to permethrin (0.75%) or deltamethrin (0.05%) in stan...

  13. The vasa regulatory region mediates germline expression and maternal transmission of proteins in the malaria mosquito Anopheles gambiae: a versatile tool for genetic control strategies

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    Burt Austin

    2009-07-01

    Full Text Available Abstract Background Germline specific promoters are an essential component of potential vector control strategies which function by genetic drive, however suitable promoters are not currently available for the main human malaria vector Anopheles gambiae. Results We have identified the Anopheles gambiae vasa-like gene and found its expression to be specifically localized to both the male and female gonads in adult mosquitoes. We have functionally characterised using transgenic reporter lines the regulatory regions required for driving transgene expression in a pattern mirroring that of the endogenous vasa locus. Two reporter constructs indicate the existence of distinct vasa regulatory elements within the 5' untranslated regions responsible not only for the spatial and temporal but also for the sex specific germline expression. vasa driven eGFP expression in the ovary of heterozygous mosquitoes resulted in the progressive accumulation of maternal protein and transcript in developing oocytes that were then detectable in all embryos and neonatal larvae. Conclusion We have characterized the vasa regulatory regions that are not only suited to drive transgenes in the early germline of both sexes but could also be utilized to manipulate the zygotic genome of developing embryos via maternal deposition of active molecules. We have used computational models to show that a homing endonuclease-based gene drive system can function in the presence of maternal deposition and describe a novel non-invasive control strategy based on early vasa driven homing endonuclease expression.

  14. Vector competence of Anopheles and Culex mosquitoes for Zika virus

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    Dodson, Brittany L.

    2017-01-01

    Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus. PMID:28316896

  15. Vector competence of Anopheles and Culex mosquitoes for Zika virus

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    Brittany L. Dodson

    2017-03-01

    Full Text Available Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus.

  16. Vector competence of Anopheles and Culex mosquitoes for Zika virus.

    Science.gov (United States)

    Dodson, Brittany L; Rasgon, Jason L

    2017-01-01

    Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus.

  17. Taxonomy Icon Data: Anopheles stephensi [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Anopheles stephensi Anopheles stephensi Arthropoda Anopheles_stephensi_L.png Anopheles_steph...ensi_NL.png Anopheles_stephensi_S.png Anopheles_stephensi_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anoph...eles+stephensi&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anopheles+stephensi&...t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anopheles+stephensi&t=S htt...p://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anopheles+stephensi&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=149 ...

  18. Biología de Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae en la Costa Pacifica de Colombia: IV - Estructura etárea y transmisión de malaria Biologia do Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae na Costa do Pacífico Colombiano: IV - Estrutura etária e transmissão da malária Biology of Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae on the Pacific Coast of Colombia: IV - Age structure and malaria transmission

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    César Murillo B.

    1989-10-01

    Full Text Available Con el fin de determinar la dinamica de transmisión de malaria en el poblado de Charambirá (Chocó, Colombia, se estudió la estructura etárea de Anopheles neivai (reconocido vector en la Costa Pacífica con base en su estado gonadotrófico. Se recolectaron mosquitos intradomiciliarmente durante el crepúsculo vespertino con cebos humanos y aspiradores bucales. Los mosquitos recolectados se mantuvieron en cajas cilíndricas de cartón con papel humedecido y dispensadores alimenticios hasta su disección al día siguiente. De los 200 mosquitos disecados entre septiembre y octubre de 1986,68 (34% presentaban huellas de menos de tres oviposturas y los restantes (66% habían efectuado al menos tres oviposturas. La diferencia entre el primer grupo considerado como mosquitos "no infectivos" y el segundo considerado como los "potencialmente infectivos" fue altamente significativa (X² = 10,68; P = 0,001. El 1,5% de A. neivai estudiados presentaban huellas correspondientes a 10 oviposturas mostrando una marcada longevidad y múltiples alimentaciones sanguíneas. Los resultados sugieren que existe un alto riesgo de contraer malaria en Charambirá durante el crepúsculo vespertino.Com o intuito de determinar a dinâmica de transmissão da malária no povoado de Charambirá (Chocó, Colômbia, foi estudada a estrutura etária do mosquito Anopheles neivai (reconhecido vetor da Costa Pacífica com base em seu estado gonadotrófico. As coletas foram realizadas intradomiciliarmente no crepúsculo vespertino com isca humana e auxílio de tubos de sucção manual. Os mosquitos coletados foram mantidos em caixas cilíndricas de papelão, contendo papel umidecido e alimento. Dos 200 mosquitos dissecados entre setembro e outubro de 1986, 68 (34% apresentaram vestígios de menos de três oviposturas (oviposições e os demais (66% apresentavam, pelo menos, três ovipoturas. A diferença entre o primeiro grupo considerado como mosquitos "não infectantes" e o

  19. Neuropeptides and Peptide Hormones in Anopheles gambiae

    Science.gov (United States)

    Riehle, Michael A.; Garczynski, Stephen F.; Crim, Joe W.; Hill, Catherine A.; Brown, Mark R.

    2002-10-01

    The African malaria mosquito, Anopheles gambiae, is specialized for rapid completion of development and reproduction. A vertebrate blood meal is required for egg production, and multiple feedings subsequently allow transmission of malaria parasites, Plasmodium spp. Regulatory peptides from 35 genes annotated from the A. gambiae genome likely coordinate these and other physiological processes. Plasmodium parasites may affect actions of newly identified insulin-like peptides, which coordinate growth and reproduction of its vector, A. gambiae, as in Drosophila melanogaster, Caenorhabditis elegans, and mammals. This genomic information provides a basis to expand understanding of hematophagy and pathogen transmission in this mosquito.

  20. Diversity of the Bacterial Microbiota of Anopheles Mosquitoes from Binh Phuoc Province, Vietnam.

    Science.gov (United States)

    Ngo, Chung T; Romano-Bertrand, Sara; Manguin, Sylvie; Jumas-Bilak, Estelle

    2016-01-01

    The naturally acquired microbiota of Anopheles can influence vector's susceptibility to Plasmodium and its capacity to transmit them. Microbiota modification is a new challenge to limit disease transmission but it still needs advanced knowledges on bacterial community in Anopheles, especially in wild and infected specimens from diverse origin and species. Bacterial culture and 16S rRNA gene-PCR associated to Temporal Temperature Gradient Electrophoresis (TTGE) were applied to explore the bacterial diversity in the abdomen of 100 wild specimens (eight Anopheles species) collected in the Binh Phuoc Province, Vietnam. Culture and PCR-TTGE were complementary. The bacterial richness of the mosquito collection encompassed 105 genera belonging to seven phyla, mostly Proteobacteria, Firmicutes, and Actinobacteria. Staphylococcus, Clostridium, and Bacillus in Firmicutes were the most prevalent genera. However, Proteobacteria represented by 57 genera was the most diversified phylum in Anopheles microbiota. The high overall of Anopheles-associated bacteria is confirmed with, to our knowledge, 51 genera described for the first time in Anopheles microbiota. However, the diversity per specimen was low with average diversity index and the average Shannon-Wiener score (H) of 4.843 and 5.569, respectively. The most represented bacterial genera were present in microbiota share by Anopheles from Binh Phuoc was very narrow, suggesting that Anopheles microbiota was greatly influenced by local environments. The repertory of bacterial genera in two specimens of An. dirus and An. pampanai naturally infected by Plasmodium vivax was also described as preliminary results. Finally, this study completed the repertory of bacteria associated to wild Anopheles. Anopheles associated-bacteria appeared specimen-dependent rather than mosquitoe species- or group-dependent. Their origin and the existence of Anopheles-specific bacterial taxa are discussed.

  1. Studies of Anopheles gambiae s.l (Diptera: Culicidae exhibiting different vectorial capacities in lymphatic filariasis transmission in the Gomoa district, Ghana

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    Amuzu Hilaria

    2010-09-01

    Full Text Available Abstract Background Two lymphatic filariasis endemic communities Mampong and Hwida in Ghana have been regularly monitored for impact on transmission after annual mass drug administration (MDA with albendazole and ivermectin. After six MDAs even though the ABR for Mampong was 55883/person/year and that of Hwida was 2494/person/year, they both had ATPs of 15.21 infective larvae/person/year. Interestingly the human microfilaraemia levels had reduced significantly from 14% to 0% at Mampong and 12% to 3% at Hwida. In an attempt to understand this anomaly, we collected mosquitoes over a 5-month period using human landing catches to determine the species composition, the number of cibarial teeth, the lengths and widths of the cibarium and the cibarial dome of the vector populations. Results Out of 2553 mosquitoes caught at Mampong, 42.6% were An. gambiae s.l. All 280 identified further by PCR were An. gambiae s.s (275 M and 5 S molecular forms. At Hwida, 112 mosquitoes were obtained; 67 (59.8% were An. gambiae s.l, comprised of 40 (59.7% An. melas, 24 (35.8% An. gambiae s.s (17 and 5 M and S molecular forms respectively and 3 (4.5% unidentified. The mean number of teeth for An. melas was 14.1 (median = 14, range = 12-15, An. gambiae s.s., 15.7 (median = 15, range = 13-19 M form 15.5 (median = 15 range = 13-19 and S form 16 (median = 16, range 15-17. The observed differences in teeth numbers were significantly different between An. melas and An. gambiae s.s (p = 0.004, and the M form (p = 0.032 and the S form (p = 0.002. Conclusions In this study, An. gambiae s.s was the main vector at Mampong and was found to possess significantly more cibarial teeth than An. melas, the principal vector at Hwida. We postulate that the different impact observed after 6 MDAs may be due to An. gambiae s.s exhibiting 'facilitation' at Mampong and at Hwida An. melas the main vector exhibits 'limitation'. Thus it may be necessary to compliment MDA with vector control to

  2. Anopheles gambiae immune responses to human and rodent Plasmodium parasite species.

    OpenAIRE

    Yuemei Dong; Ruth Aguilar; Zhiyong Xi; Emma Warr; Emmanuel Mongin; George Dimopoulos

    2006-01-01

    Transmission of malaria is dependent on the successful completion of the Plasmodium lifecycle in the Anopheles vector. Major obstacles are encountered in the midgut tissue, where most parasites are killed by the mosquito's immune system. In the present study, DNA microarray analyses have been used to compare Anopheles gambiae responses to invasion of the midgut epithelium by the ookinete stage of the human pathogen Plasmodium falciparum and the rodent experimental model pathogen P. berghei. I...

  3. Détermination des paramètres bioécologiques et entomologiques d’Anopheles gambiae sl dans la transmission du paludisme à Bandundu-ville, République Démocratique de Congo

    Science.gov (United States)

    Matubi, Emery Metelo; Bukaka, Eric; Luemba, Trésor Bakambana; Situakibanza, Hyppolite; Sangaré, Ibrahim; Mesia, Gauthier; Ngoyi, Dieudonné Mumba; Maniania, Nguya Kalemba; Akikwa, Charles Ngandote; Kanza, Jean Pierre Basilua; Tamfum, Jean-Jacques Muyembe; sudi, Jonas Nagahuedi Bongo

    2015-01-01

    Introduction La présente étude a été menée à Bandundu-ville (RDC) en vue d'identifier les paramètres écologiques et entomologiques modulant la transmission du paludisme ainsi que leur tendance saisonnière dans cette agglomération. Méthodes Cette étude a été réalisée dans la période du 1er juin au 31 décembre 2011. Des prospections des gîtes larvaires d'anophèles avec récolte ont été réalisées, les paramètres physiques, physico-chimiques et environnementaux déterminés. La densité larvaire a été estimée selon une échelle de classes de densité, inspirée de la méthode de Carron pour chaque type de gîtes. Quarante-huit maisons ont été sélectionnées et prospectées pour la récolte des moustiques par pulvérisation intradomicilaire. L'identification des moustiques a été faite sur base des critères morphologiques de Gilles et Demeillon. L'Indice sporozoïtique (Is) a été déterminé par le test ELISA CSP de Plasmodium falciparum à l'Institut National de Recherche Biomédicale selon le protocole de Robert Wirtz. Les autres paramètres entomologiques comme la densité, le taux d'agressivité, le taux d'inoculation entomologique (TIE) ainsi que l'indice de stabilité ont été déterminés selon le protocole de l'OMS. La régression linéaire a été réalisée au seuil de signification de 0,05 pour identifier les déterminants de la densité larvaire. Résultats Cent-sept gîtes larvaires ont été identifiés et caractérisés en 5 types (digues et puits d'eau, collections d'eau maraîchère et concasseurs moellons, marais Régie de distribution d'eau, marais le long des rivières et ruisseaux et flaques d'eau de pluies). La densité larvaire moyenne a été de 117,4±64,1. Quatre mille cinq cents quatre-vingt-huit moustiques ont été capturés et identifiés, parmi lesquels 1.258 Anopheles gambiae sl avec une densité de 8,86, un taux d'agressivité de 1,55 piqûre par homme par nuit, l'Is de 5,6%, un TIE de 0,085 piq

  4. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozonn cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossum, Didelphis virginiana, from Southern Louisian

    Science.gov (United States)

    We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoan’s of veterinary importance (Neospora caninum, Sarcocystis neurona and Besnoitia darlingi) in a population of North American opossums (Didelphis...

  5. Evidence of natural Wolbachia infections in field populations of Anopheles gambiae

    Science.gov (United States)

    Baldini, Francesco; Segata, Nicola; Pompon, Julien; Marcenac, Perrine; Robert Shaw, W.; Dabiré, Roch K.; Diabaté, Abdoulaye; Levashina, Elena A.; Catteruccia, Flaminia

    2014-01-01

    Wolbachia are maternally transmitted intracellular bacteria that invade insect populations by manipulating their reproduction and immunity and thus limiting the spread of numerous human pathogens. Experimental Wolbachia infections can reduce Plasmodium numbers in Anopheles mosquitoes in the laboratory, however, natural Wolbachia infections in field anophelines have never been reported. Here we show evidence of Wolbachia infections in Anopheles gambiae in Burkina Faso, West Africa. Sequencing of the 16S rRNA gene identified Wolbachia sequences in both female and male germlines across two seasons, and determined that these sequences are vertically transmitted from mother to offspring. Whole-genome sequencing of positive samples suggests that the genetic material identified in An. gambiae belongs to a novel Wolbachia strain, related to but distinct from strains infecting other arthropods. The evidence of Wolbachia infections in natural Anopheles populations promotes further investigations on the possible use of natural Wolbachia–Anopheles associations to limit malaria transmission. PMID:24905191

  6. Assessment of Anopheles salivary antigens as individual exposure biomarkers to species-specific malaria vector bites

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    Ali Zakia M I

    2012-12-01

    Full Text Available Abstract Background Malaria transmission occurs during the blood feeding of infected anopheline mosquitoes concomitant with a saliva injection into the vertebrate host. In sub-Saharan Africa, most malaria transmission is due to Anopheles funestus s.s and to Anopheles gambiae s.l. (mainly Anopheles gambiae s.s. and Anopheles arabiensis. Several studies have demonstrated that the immune response against salivary antigens could be used to evaluate individual exposure to mosquito bites. The aim of this study was to assess the use of secreted salivary proteins as specific biomarkers of exposure to An. gambiae and/or An. funestus bites. Methods For this purpose, salivary gland proteins 6 (SG6 and 5′nucleotidases (5′nuc from An. gambiae (gSG6 and g-5′nuc and An. funestus (fSG6 and f-5′nuc were selected and produced in recombinant form. The specificity of the IgG response against these salivary proteins was tested using an ELISA with sera from individuals living in three Senegalese villages (NDiop, n = 50; Dielmo, n = 38; and Diama, n = 46 that had been exposed to distinct densities and proportions of the Anopheles species. Individuals who had not been exposed to these tropical mosquitoes were used as controls (Marseille, n = 45. Results The IgG responses against SG6 recombinant proteins from these two Anopheles species and against g-5′nucleotidase from An. gambiae, were significantly higher in Senegalese individuals compared with controls who were not exposed to specific Anopheles species. Conversely, an association was observed between the level of An. funestus exposure and the serological immune response levels against the f-5′nucleotidase protein. Conclusion This study revealed an Anopheles salivary antigenic protein that could be considered to be a promising antigenic marker to distinguish malaria vector exposure at the species level. The epidemiological interest of such species-specific antigenic markers is discussed.

  7. Fauna and some biological characteristics of Anopheles mosquitoes (Diptera:Culicidae) in Kalaleh County, Golestan Province, northeast of lran

    Institute of Scientific and Technical Information of China (English)

    Aioub Sofizadeh; Hamideh Edalat; Mohammad Reza Abai; Ahmad Ali Hanafi-Bojd

    2016-01-01

    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.

  8. Male motion coordination in swarming Anopheles gambiae and Anopheles coluzzii

    Science.gov (United States)

    The Anopheles gambiae species complex comprises the primary vectors of malaria in much of sub-Saharan Africa; most of the mating in these species occurs in swarms composed almost entirely of males. Intermittent, parallel flight patterns in such swarms have been observed, but a detailed description o...

  9. Bacterial diversity associated with wild caught Anopheles mosquitoes from Dak Nong Province, Vietnam using culture and DNA fingerprint.

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    Chung Thuy Ngo

    Full Text Available Microbiota of Anopheles midgut can modulate vector immunity and block Plasmodium development. Investigation on the bacterial biodiversity in Anopheles, and specifically on the identification of bacteria that might be used in malaria transmission blocking approaches, has been mainly conducted on malaria vectors of Africa. Vietnam is an endemic country for both malaria and Bancroftian filariasis whose parasitic agents can be transmitted by the same Anopheles species. No information on the microbiota of Anopheles mosquitoes in Vietnam was available previous to this study.The culture dependent approach, using different mediums, and culture independent (16S rRNA PCR - TTGE method were used to investigate the bacterial biodiversity in the abdomen of 5 Anopheles species collected from Dak Nong Province, central-south Vietnam. Molecular methods, sequencing and phylogenetic analysis were used to characterize the microbiota.The microbiota in wild-caught Anopheles was diverse with the presence of 47 bacterial OTUs belonging to 30 genera, including bacterial genera impacting Plasmodium development. The bacteria were affiliated with 4 phyla, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, the latter being the dominant phylum. Four bacterial genera are newly described in Anopheles mosquitoes including Coxiella, Yersinia, Xanthomonas, and Knoellia. The bacterial diversity per specimen was low ranging from 1 to 4. The results show the importance of pairing culture and fingerprint methods to better screen the bacterial community in Anopheles mosquitoes.Sampled Anopheles species from central-south Vietnam contained a diverse bacterial microbiota that needs to be investigated further in order to develop new malaria control approaches. The combination of both culture and DNA fingerprint methods allowed a thorough and complementary screening of the bacterial community in Anopheles mosquitoes.

  10. Bacterial Diversity Associated with Wild Caught Anopheles Mosquitoes from Dak Nong Province, Vietnam Using Culture and DNA Fingerprint

    Science.gov (United States)

    Ngo, Chung Thuy; Aujoulat, Fabien; Veas, Francisco; Jumas-Bilak, Estelle; Manguin, Sylvie

    2015-01-01

    Background Microbiota of Anopheles midgut can modulate vector immunity and block Plasmodium development. Investigation on the bacterial biodiversity in Anopheles, and specifically on the identification of bacteria that might be used in malaria transmission blocking approaches, has been mainly conducted on malaria vectors of Africa. Vietnam is an endemic country for both malaria and Bancroftian filariasis whose parasitic agents can be transmitted by the same Anopheles species. No information on the microbiota of Anopheles mosquitoes in Vietnam was available previous to this study. Method The culture dependent approach, using different mediums, and culture independent (16S rRNA PCR – TTGE) method were used to investigate the bacterial biodiversity in the abdomen of 5 Anopheles species collected from Dak Nong Province, central-south Vietnam. Molecular methods, sequencing and phylogenetic analysis were used to characterize the microbiota. Results and Discussion The microbiota in wild-caught Anopheles was diverse with the presence of 47 bacterial OTUs belonging to 30 genera, including bacterial genera impacting Plasmodium development. The bacteria were affiliated with 4 phyla, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, the latter being the dominant phylum. Four bacterial genera are newly described in Anopheles mosquitoes including Coxiella, Yersinia, Xanthomonas, and Knoellia. The bacterial diversity per specimen was low ranging from 1 to 4. The results show the importance of pairing culture and fingerprint methods to better screen the bacterial community in Anopheles mosquitoes. Conclusion Sampled Anopheles species from central-south Vietnam contained a diverse bacterial microbiota that needs to be investigated further in order to develop new malaria control approaches. The combination of both culture and DNA fingerprint methods allowed a thorough and complementary screening of the bacterial community in Anopheles mosquitoes. PMID:25747513

  11. Identification of four evolutionarily related G protein-coupled receptors from the malaria mosquito Anopheles gambiae

    DEFF Research Database (Denmark)

    Belmont, Martin; Cazzamali, Giuseppe; Williamson, Michael

    2006-01-01

    The mosquito Anopheles gambiae is an important vector for malaria, which is one of the most serious human parasitic diseases in the world, causing up to 2.7 million deaths yearly. To contribute to our understanding of A. gambiae and to the transmission of malaria, we have now cloned four evolutio...

  12. Factors affecting the vectorial competence of Anopheles gambiae: a question of scale

    NARCIS (Netherlands)

    Takken, W.; Lindsay, S.W.

    2003-01-01

    Malaria transmission in Africa is without doubt governed by the existence of a group of highly efficient vectors, of which Anopheles gambiae Giles sensu stricto is predominant. The endophilic and anthropophagic behaviours of this mosquito create an intimate association between the human reservoir an

  13. The resting sites and blood-meal sources of Anopheles minimus in Taiwan

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    Chen Yung-Chen

    2008-06-01

    Full Text Available Abstract Background The WHO declared Taiwan free from malaria in 1965, but in 2003 the reporting of two introduced cases in a rural area suggested a possible local transmission of this disease. Therefore, understanding the resting sites and the blood sources of Anopheles minimus is crucial in order to provide information for implementing vector control strategies. Methods During a two-year survey, mosquitoes were collected in houses and their surrounding areas and at the bank of larval habitats by backpack aspirators in 17 villages in rural areas of southern and eastern Taiwan for 1 hr. On the same day, blacklight traps were hung downward overnight. Blood-fed mosquito samples were analysed by PCR. Results Of the 195 total households surveyed by backpack aspirators, no Anopheles adults were collected inside the houses, while a single Anopheles minimus and a single Anopheles maculatus were collected outside of the houses. On the same day, 23 An. minimus, two An. maculatus, two Anopheles ludlowae, two Anopheles sinensis, and one Anopheles tessellatus were collected along the bank of larval habitats. In blacklight traps hung outside of the houses in the villages, 69 An. minimus, 62 An. ludlowae, 31 An. sinensis, and 19 An. maculatus were collected. In larval habitats, 98 An. ludlowae, 64 An. minimus, 49 An. sinensis, and 14 An. maculatus were collected. Of a total of 10 blood-fed samples, An. minimus fed on four animals including bovine (60%, dogs (20%, pig (10%, and non-chicken avian (10%. Conclusion Anopheles minimus, an opportunist feeder in Taiwan, was not collected inside the houses, but was found outside of the houses in villages and surrounding larval habitats. Therefore, an outdoor transmission of malaria is likely to occur and, thus, the bed nets, which are favoured for controlling the late biting of An. minimus, should be a very efficient and effective method for those local residents who sleep outdoors. Additionally, space spray of

  14. The nicotinic acetylcholine receptor gene family of the malaria mosquito, Anopheles gambiae.

    Science.gov (United States)

    Jones, Andrew K; Grauso, Marta; Sattelle, David B

    2005-02-01

    Nicotinic acetylcholine receptors (nAChRs) mediate fast cholinergic synaptic transmission in the insect nervous system and are targets of widely selling insecticides. We have identified the nAChR gene family from the genome of the malaria mosquito vector, Anopheles gambiae, to be the second complete insect nAChR gene family described following that of Drosophila melanogaster. Like Drosophila, Anopheles possesses 10 nAChR subunits with orthologous relationships evident between the two insects. Interestingly, the Anopheles orthologues of Dbeta2 and Dbeta3 possess the vicinal cysteines that define alpha subunits. As with Dalpha4 and Dalpha6, the Anopheles orthologues are alternatively spliced at equivalent exons. Reverse transcription-polymerase chain reaction analysis shows that RNA A-to-I editing sites conserved between Dalpha6 of Drosophila and alpha7-2 of the tobacco budworm, Heliothis virescens, are not shared with the equivalent nAChR subunit of Anopheles. Indeed, RNA-editing sites identified in functionally significant regions of Dbeta1, Dalpha5, and Dalpha6 are not conserved in the mosquito orthologues, indicating considerable divergence of RNA molecules targeted for editing within the insect order Diptera. These findings shed further light on the diversity of nAChR subunits and may present a useful basis for the development of improved malaria control agents by enhancing our understanding of a validated mosquito insecticide target.

  15. Metabolic Pathways in Anopheles stephensi mitochondria

    Science.gov (United States)

    Giulivi, Cecilia; Ross-Inta, Catherine; Horton, Ashley A.; Luckhart, Shirley

    2017-01-01

    No studies have been performed on mitochondria of malaria vector mosquitoes. This information would be valuable in understanding mosquito aging and detoxification of insecticides, two parameters that significantly impact malaria parasite transmission in endemic regions. Here, we report the analyses of respiration and oxidative phosphorylation in mitochondria of cultured cells (ASE line) from Anopheles stephensi, a major vector of malaria in India, Southeast Asia and parts of the Middle East. ASE cell mitochondria shared many features in common with mammalian muscle mitochondria, despite the fact that these cells have a larval origin. However, two major differences with mammalian mitochondria were apparent. One, the glycerol-phosphate shuttle plays a major role in NADH oxidation in ASE cell mitochondria as it does in insect muscle mitochondria. In contrast, mammalian white muscle mitochondria depend primarily on lactate dehydrogenase, whereas red muscle mitochondria depend on the malate-oxaloacetate shuttle. Two, ASE mitochondria were able to oxidize Pro at a rate comparable with that of α-glycerophosphate. However, the Pro pathway appeared to differ from the currently accepted pathway, in that ketoglutarate could be catabolyzed completely by the Krebs cycle or via transamination depending on the ATP need. PMID:18588503

  16. Metabolic pathways in Anopheles stephensi mitochondria.

    Science.gov (United States)

    Giulivi, Cecilia; Ross-Inta, Catherine; Horton, Ashley A; Luckhart, Shirley

    2008-10-15

    No studies have been performed on the mitochondria of malaria vector mosquitoes. This information would be valuable in understanding mosquito aging and detoxification of insecticides, two parameters that have a significant impact on malaria parasite transmission in endemic regions. In the present study, we report the analyses of respiration and oxidative phosphorylation in mitochondria of cultured cells [ASE (Anopheles stephensi Mos. 43) cell line] from A. stephensi, a major vector of malaria in India, South-East Asia and parts of the Middle East. ASE cell mitochondria share many features in common with mammalian muscle mitochondria, despite the fact that these cells are of larval origin. However, two major differences with mammalian mitochondria were apparent. One, the glycerol-phosphate shuttle plays as major a role in NADH oxidation in ASE cell mitochondria as it does in insect muscle mitochondria. In contrast, mammalian white muscle mitochondria depend primarily on lactate dehydrogenase, whereas red muscle mitochondria depend on the malate-oxaloacetate shuttle. Two, ASE mitochondria were able to oxidize proline at a rate comparable with that of alpha-glycerophosphate. However, the proline pathway appeared to differ from the currently accepted pathway, in that oxoglutarate could be catabolized completely by the tricarboxylic acid cycle or via transamination, depending on the ATP need.

  17. Fitness consequences of Anopheles gambiae population hybridization

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    Beier John C

    2005-09-01

    Full Text Available Abstract Background The use of transgenic mosquitoes with parasite inhibiting genes has been proposed as an integral strategy to control malaria transmission. However, release of exotic transgenic mosquitoes will bring in novel alleles along with parasite-inhibiting genes that may have unknown effects on native populations. Thus it is necessary to study the effects and dynamics of fitness traits in native mosquito populations in response to the introduction of novel genes. This study was designed to evaluate the dynamics of fitness traits in a simulation of introduction of novel alleles under laboratory conditions using two strains of Anopheles gambiae: Mbita strain from western Kenya and Ifakara strain from Tanzania. Methods The dynamics of fitness traits were evaluated under laboratory conditions using the two An. gambiae strains. These two geographically different strains were cross-bred and monitored for 20 generations to score fecundity, body size, blood-meal size, larval survival, and adult longevity, all of which are important determinants of the vector's potential in malaria transmission. Traits were analysed using pair-wise analysis of variance (ANOVA for fecundity, body size, and blood-meal size while survival analysis was performed for larval survival and adult longevity. Results Fecundity and body size were significantly higher in the progeny up to the 20th generation compared to founder strains. Adult longevity had a significantly higher mean up to the 10th generation and average blood-meal size was significantly larger up to the 5th generation, indicating that hybrids fitness is enhanced over that of the founder strains. Conclusion Hybridization of the two mosquito populations used in this study led to increased performance in the fitness traits studied. Given that the studied traits are important determinants of the vector's potential to transmit malaria, these results suggest the need to release genetically modified mosquitoes

  18. A Population Genetics Study of Anopheles Darlingi (Diptera: Culicidae) from Colombia Based on Random Amplified Polymorphic DNA-Polymerase Chain Reaction and Amplified Fragment Length Polymorphism Markers

    Science.gov (United States)

    2007-06-01

    biogeographic province population from those of rhe Choco -MagdCllena. In this lasr region. Choco Clnd Cordoba populations showed the Ilighest genetic flow. Key...Atrato, Choco Province; Granada (030 32’ 19" N and 73° W) in the municipality of Granada, Meta Province; and Tai in the municipality of lierralta...darling; popu- lalions: Rete ( Choco ), Tierrallll (Cordoba), and Granada (Meta). PERU ~ uo u u:: i3 ~ ECUADOR 1996, Rafael & Tadei 1998,2000, 1999

  19. Anopheles moucheti and Anopheles vinckei are candidate vectors of ape Plasmodium parasites, including Plasmodium praefalciparum in Gabon.

    Science.gov (United States)

    Paupy, Christophe; Makanga, Boris; Ollomo, Benjamin; Rahola, Nil; Durand, Patrick; Magnus, Julie; Willaume, Eric; Renaud, François; Fontenille, Didier; Prugnolle, Franck

    2013-01-01

    During the last four years, knowledge about the diversity of Plasmodium species in African great apes has considerably increased. Several new species were described in chimpanzees and gorillas, and some species that were previously considered as strictly of human interest were found to be infecting African apes. The description in gorillas of P. praefalciparum, the closest relative of P. falciparum which is the main malignant agent of human malaria, definitively changed the way we understand the evolution and origin of P. falciparum. This parasite is now considered to have appeared recently, following a cross-species transfer from gorillas to humans. However, the Plasmodium vector mosquito species that have served as bridge between these two host species remain unknown. In order to identify the vectors that ensure ape Plasmodium transmission and evaluate the risk of transfer of these parasites to humans, we carried out a field study in Gabon to capture Anopheles in areas where wild and semi-wild ape populations live. We collected 1070 Anopheles females belonging to 15 species, among which An. carnevalei, An. moucheti and An. marshallii were the most common species. Using mtDNA-based PCR tools, we discovered that An. moucheti, a major human malaria vector in Central Africa, could also ensure the natural transmission of P. praefalciparum among great apes. We also showed that, together with An. vinckei, An. moucheti was infected with P. vivax-like parasites. An. moucheti constitutes, therefore, a major candidate for the transfer of Plasmodium parasites from apes to humans.

  20. New selenoproteins identified in silico from the genome of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    JIANG Liang; LIU Qiong; CHEN Ping; GAO ZhongHong; XU HuiBi

    2007-01-01

    Selenoprotein is biosynthesized by the incorporation of selenocysteine into proteins, where the TGA codon in the open reading frame does not act as a stop signal but is translated into selenocysteine. The dual functions of TGA result in mis-annotation or lack of selenoproteins in the sequenced genomes of many species. Available computational tools fail to correctly predict selenoproteins. Thus, we developed a new method to identify selenoproteins from the genome of Anopheles gambiae computationally.Based on released genomic information, several programs were edited with PERL language to identify selenocysteine insertion sequence (SECIS) element, the coding potential of TGA codons, and cysteine-containing homologs of selenoprotein genes. Our results showed that 11365 genes were terminated with TGA codons, 918 of which contained SECIS elements. Similarity search revealed that 58genes contained Sec/Cys pairs and similar flanking regions around in-frame TGA codons. Finally, 7genes were found to fully meet requirements for selenoproteins, although they have not been annotated as selenoproteins in NCBI databases. Deduced from their basic properties, the newly found selenoproteins in the genome of Anopheles gambiae are possibly related to in vivo oxidation tolerance and protein regulation in order to interfere with anopheles' vectorial capacity of Plasmodium. This study may also provide theoretical bases for the prevention of malaria from anopheles transmission.

  1. Espécies de Anopheles no município de Pinheiro (Maranhão, área endêmica de malária Species of Anopheles in Pinheiro municipality (Maranhão, endemic area of malaria

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    Yrla Nívea Oliveira-Pereira

    2000-10-01

    Full Text Available A riqueza, abundância relativa, flutuação sazonal, preferência por ambiente (peri e intradomicílio e horários de hematofagismo de espécies de Anopheles foram estudados no município de Pinheiro, Maranhão. As fêmeas foram capturadas mensalmente sobre iscas humanas de maio/1998 a abril/1999, das 18 às 6 horas. Foram coletados 1.321 espécimens pertencentes a 10 espécies de Anopheles, todas do subgênero Nyssorhynchus: A. argyritarsis com 62%, A. darlingi (21,7%, A. albitarsis (4,5%, A. galvaoi (4%, A. triannulatus (3,1% e A. evansae (2,8%. As espécies A. nuneztovari, A. braziliensis, A. rondoni e A. strodei representaram juntas 1,9%. Os anofelinos ocorreram o ano todo, não havendo diferença significativa no número de exemplares capturados entre as estações chuvosa (51,7% e seca (48,3%. A freqüência dos anofelinos no peridomicílio foi significativamente maior (p The Anophelae species of the municipal district of Pinheiro, Maranhão State, Brazil, were studied, considering their variety, relative abundance, seasonal fluctuation, preference by the peri and intra domiciles as well as the hours of hematophagism. The females were captured using human bait, on a monthly basis from May/1998 to April/1999, from 6 p.m. to 6 a.m. A total of 1,321 specimens of 10 species were captured, all belonging to the subgenus Nyssorhynchus. The most frequent species were A. argyritarsis (62%, A. darlingi (21.7%, A. albitarsis (4.5%, A. galvaoi (4.0%, A. triannulatus (3.1% and A. evansae (2.8%. The species A. nuneztovari, A. braziliensis, A. rondoni and A. strodei together represented 1.9%. The anophelines occurred all year round, with no significant difference in the number of specimens captured between the rainy (51.7% and dry season (48.3%. The frequency of the females in the peridomicile was significantly higher (p < 0.01 (82%, than in the intradomicile (18%, preferring to suck blood at dusk and in the first hours of the night.

  2. HABITAT PERKEMBANGBIAKAN DAN AKTIVITAS MENGGIGIT NYAMUK ANOPHELES SUNDAICUS DAN ANOPHELES SUBPICTUS DI PURWOREJO, JAWA TENGAH

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    Supratman Sukowati

    2012-11-01

    Full Text Available Malaria continues to be a public health problem, it causes morbidity, mortality as well as outbreak in several remote areas in Indonesia. Vector control remains the most effective measure to prevent malaria transmission. The understanding of mosquito species, its bio-ecology, and the characteristic of their habitats are very important to formulate the vector control strategy. It was recognized that there are many aspects of behavior that are directly and indirectly important in the prevention and control of malaria. One of the main cause of malaria control failure due to lack of understanding vector spesies and its bio-ecology.This paper reported the study of breeding places and biting activities of malaria vector Anophles sundaicus and An. subpictus from coastal area of Purworejo area in year 2004. Natural population of anopheline species was sampled from larval survey, landing collection, animal resting collection, resting collection to study the larval habitat, biting activities, resting habit and biting sites. Nine species of anopheline werefound in Jati Malang e.g. An. sundaicus, An. subpictus, An. barbirostris, An. vagus, An. aconitus, An.indefinitus, An. tesselatus, An. nigerrimus, An. annularis. In Gedangan village was found 5 species of Anopheles e.g. An. sundaicus, An. subpictus, An. barbirostris, An. vagus, and An. aconitus.The breeding places of Anopheles spp. are varied, in Jati Malang and Gedangan were found lagoon, brackish water fish-pond, rice field, freshwater fishpond, irrigation channel, and pit hole. Therefore, the breeding places of An. sundaicus and An. subpictus confined in the lagoon and brackish water fish ponds, with its characteristics e.g. water temperature ranges 25,6°C-27,8°C, pH ranges 7,2-7,6, water salinity 3,0-3,4%, and water dept is 20,3 cm-25,2 cm, muddy undergroud, stagnant or slow running water with the water weed mostly green algae (Chlorophyta and lichen.The biting activities of An. sundaicus and An

  3. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

  4. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background: Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (specie

  5. Thermal limits of wild and laboratory strains of two African malaria vector species, Anopheles arabiensis and Anopheles funestus

    Directory of Open Access Journals (Sweden)

    Lyons Candice L

    2012-07-01

    Full Text Available Abstract Background Malaria affects large parts of the developing world and is responsible for almost 800,000 deaths annually. As climates change, concerns have arisen as to how this vector-borne disease will be impacted by changing rainfall patterns and warming temperatures. Despite the importance and controversy surrounding the impact of climate change on the potential spread of this disease, little information exists on the tolerances of several of the vector species themselves. Methods Using a ramping protocol (to assess critical thermal limits - CT and plunge protocol (to assess lethal temperature limits - LT information on the thermal tolerance of two of Africa’s important malaria vectors, Anopheles arabiensis and Anopheles funestus was collected. The effects of age, thermal acclimation treatment, sex and strain (laboratory versus wild adults were investigated for CT determinations for each species. The effects of age and sex for adults and life stage (larvae, pupae, adults were investigated for LT determinations. Results In both species, females are more tolerant to low and high temperatures than males; larvae and pupae have higher upper lethal limits than do adults. Thermal acclimation of adults has large effects in some instances but small effects in others. Younger adults tend to be more tolerant of low or high temperatures than older age groups. Long-standing laboratory colonies are sufficiently similar in thermal tolerance to field-collected animals to provide reasonable surrogates when making inferences about wild population responses. Differences between these two vectors in their thermal tolerances, especially in larvae and pupae, are plausibly a consequence of different habitat utilization. Conclusions Limited plasticity is characteristic of the adults of these vector species relative to others examined to date, suggesting limited scope for within-generation change in thermal tolerance. These findings and the greater tolerance

  6. Genomic Dark Matter Illuminated: Anopheles Y Chromosomes.

    Science.gov (United States)

    Redmond, Seth N; Neafsey, Daniel E

    2016-08-01

    Hall et al. have strategically used long-read sequencing technology to characterize the structure and highly repetitive content of the Y chromosome in Anopheles malaria mosquitoes. Their work confirms that this important but elusive heterochromatic sex chromosome is evolving extremely rapidly and harbors a remarkably small number of genes.

  7. KONFIRMASI STATUS ANOPHELES VAGUS SEBAGAI VEKTOR PENDAMPING SAAT KEJADIAN LUAR BIASA MALARIA DI KABUPATEN SUKABUMI INDONESIA

    Directory of Open Access Journals (Sweden)

    Amrul Munif

    2012-11-01

    Full Text Available Confirmation A nopheles Vagus As Vector Implicated Malaria Outbreak In Sukabumi District, Indonesia.A study on adult anopheline of malaria vector incrimination for the vector status ofAn. aconitus, An.sundaicus and An. barbirostris, An. vagus were infected with malaria parasites was conducted in Simpenan sub-district, Sukabumi district, West Java from January 2003 to February 2003. The observation of the identification of Anopheles spp. and its relationship with outbreak malaria as well as the determination of Anopheles spp. as malaria vectors in endemic areas should be given attention as an effort in preventing malaria outbreaks. Adult mosquitoes were collected from human bait indoor and outdoor catches. Mosquitoes head-thoraces were tested for the presence of circumsporozoite of Plasmodium falciparum and P. vivax for the presence of human blood by ELISA. A total of 3,308 female anophelines representing 9 spesies were collected. Nine identified Anopheles species ie: An.aconitus, An.sundaicus, An maculatus, An.indefinitus, An. vagus, An. baezai, An.kochi, An.barbirostris and An.annularis, recorded during outbreak, were the main vectors of malaria in the Simpenan district. Malaria parasite infections were seen in nine mosquito species, with natural infection 0.12% of the positive An. vagus mosquitoes containing P. faciparum. An. vagus occurring in abundance, was involved in malaria transmission in outbreak period. The average inoculation rate was 0,213 While there was strong ELISA-based evidence implicating An. vagus as a dominant vector. Of these, An.aconitus, An.maculatus and An.sundaicus are suspected primary malaria vector in Simpenan sub-district, Sukabumi district, Indonesia, but An. vagus has been implicated with certainty in malaria transmission in the country.Keywords: Anopheles, vagus, vector status, ELISA, outbreak, implicated vector

  8. Mosquito transgenic technologies to reduce Plasmodium transmission.

    Science.gov (United States)

    Fuchs, Silke; Nolan, Tony; Crisanti, Andrea

    2013-01-01

    The ability to introduce genetic constructs of choice into the genome of Anopheles mosquitoes provides a valuable tool to study the molecular interactions between the Plasmodium parasite and its insect host. In the long term, this technology could potentially offer new ways to control vector-borne diseases through the suppression of target mosquito populations or through the introgression of traits that preclude pathogen transmission. Here, we describe in detail protocols for the generation of transgenic Anopheles gambiae mosquitoes based on germ-line transformation using either modified transposable elements or the site-specific PhiC31 recombinase.

  9. Vectorial status and insecticide resistance of Anopheles funestus from a sugar estate in southern Mozambique

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    Nhamahanga Eduardo

    2011-02-01

    Full Text Available Abstract Background The dual problems of rising insecticide resistance in the malaria vectors and increasing human malaria cases since 2001 in southern Mozambique are cause for serious concern. The selection of insecticides for use in indoor residual spraying (IRS programmes is highly dependent on the extent to which local mosquitoes are susceptible to the approved classes of insecticides. The insecticide resistance status and role in malaria transmission of Anopheles funestus was evaluated at the Maragra Sugar Estate in southern Mozambique where an IRS vector control programme has been in operation for seven years using the carbamate insecticide bendiocarb. Results No Anopheles species were captured inside the sugar estate control area. Anopheles funestus group captured outside of the estate represented 90% (n = 475 of the total collections. Of the specimens identified to species by PCR (n = 167, 95% were An. funestus s.s. One An. rivulorum was identified and seven specimens did not amplify. The Anopheles gambiae complex was less abundant (n = 53 and of those identified (n = 33 76% were An. arabiensis and 24% An. merus. Insecticide susceptibility tests showed that wild-caught and F-1 family An. funestus were resistant to deltamethrin (32.5% mortality and lambda-cyhalothrin (14.6% mortality, less so to bendiocarb (71.5% mortality and fully susceptible to both malathion and DDT (100%. Bendiocarb and pyrethroid resistance was nullified using 4% piperonyl butoxide (Pbo, strongly suggesting that both are mediated by P450 monooxygenase detoxification. ELISA tests of An. funestus for Plasmodium falciparum, gave a sporozoite rate of 6.02% (n = 166. One unidentified member of the An. gambiae complex tested positive for P. falciparum sporozoites. Conclusion Anopheles funestus was found to be the most abundant and principle vector of malaria in this area, with members of the An. gambiae complex being secondary vectors. Despite the continual use of

  10. Anopheles (Anopheles) petragnani Del Vecchio 1939-a new mosquito species for Germany.

    Science.gov (United States)

    Becker, Norbert; Pfitzner, Wolf Peter; Czajka, Christina; Kaiser, Achim; Weitzel, Thomas

    2016-07-01

    The so far known species of the Anopheles Claviger Complex, Anopheles claviger s.s. and Anopheles petragnani, can only be distinguished by partial overlapping characteristics of immature stages and by nucleotide sequence variation of the genomic ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS2) region. The known distribution of An. petragnani is so far restricted to the western Mediterranean region, whereas An. claviger s.s. occurs across most of Europe, up to the Middle East and North Africa. In our study, we investigated the larval mosquito fauna in rock pools of the Murg valley (Black Forest, Germany) once a month from April to December 2015.Among other species, larvae belonging to the Anopheles Claviger Complex were found. The fourth instar larvae were morphologically identified by chaetotaxy of the head and abdomen. The results were confirmed by a multiplex PCR and additional sequencing of the amplificates.Of the 1289 collected larvae from the rock pools, seven belonged to the Anopheles Claviger Complex. Five individuals were determined morphologically as An. petragnani and two as An. claviger s.s. The associated mosquito fauna comprised of Aedes japonicus japonicus (548 individuals), Culex pipiens s.l. and Culex torrentium (493 individuals) and Culex hortensis (241 individuals).This is the first record of An. petragnani north of the Alps. Further studies will reveal whether this is an isolated population of An. petragnani and if the investigated rock pool breeding sites represent typical habitats of this species in temperate regions in Central Europe.

  11. Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control

    NARCIS (Netherlands)

    Ageep, T.B.; Cox, J.; Hassan, M.M.; Knols, B.G.J.; Benedict, M.Q.; Malcolm, C.A.; Babiker, A.; Sayed, El B.B.

    2009-01-01

    Background - Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on

  12. Spatial association between malaria vector species richness and malaria in Colombia.

    Science.gov (United States)

    Fuller, Douglas O; Alimi, Temitope; Herrera, Socrates; Beier, John C; Quiñones, Martha L

    2016-06-01

    Malaria transmission in Colombia is highly variable in space and time. Using a species distribution model, we mapped potential distribution of five vector species including Anopheles albimanus, Anopheles calderoni, Anopheles darlingi, Anopheles neivai, and Anopheles nuneztovari in five Departments of Colombia where malaria transmission remains problematic. We overlaid the range maps of the five species to reveal areas of sympatry and related per-pixel species richness to mean annual parasite index (API) for 2011-2014 mapped by municipality (n = 287). The relationship between mean number of vector species per municipality and API was evaluated using a Poisson regression, which revealed a highly significant relationship between species richness and API (p = 0 for Wald Chi-Square statistic). The results suggest that areas of relatively high transmission in Colombia typically contain higher number of vector species than areas with unstable transmission and that future elimination strategies should account for vector species richness.

  13. New selenoproteins identified in silico from the genome of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Selenoprotein is biosynthesized by the incorporation of selenocysteine into proteins,where the TGA codon in the open reading frame does not act as a stop signal but is translated into selenocysteine.The dual functions of TGA result in mis-annotation or lack of selenoproteins in the sequenced genomes of many species.Available computational tools fail to correctly predict selenoproteins.Thus,we devel-oped a new method to identify selenoproteins from the genome of Anopheles gambiae computationally.Based on released genomic information,several programs were edited with PERL language to identify selenocysteine insertion sequence(SECIS)element,the coding potential of TGA codons,and cys-teine-containing homologs of selenoprotein genes.Our results showed that 11365 genes were termi-nated with TGA codons,918 of which contained SECIS elements.Similarity search revealed that 58 genes contained Sec/Cys pairs and similar flanking regions around in-frame TGA codons.Finally,7 genes were found to fully meet requirements for selenoproteins,although they have not been anno-tated as selenoproteins in NCBI databases.Deduced from their basic properties,the newly found se-lenoproteins in the genome of Anopheles gambiae are possibly related to in vivo oxidation tolerance and protein regulation in order to interfere with anopheles’ vectorial capacity of Plasmodium.This study may also provide theoretical bases for the prevention of malaria from anopheles transmission.

  14. Ability of TEP1 in intestinal flora to modulate natural resistance of Anopheles dirus.

    Science.gov (United States)

    Wang, Yanyan; Wang, Ying; Zhang, Jingru; Xu, Wenyue; Zhang, Jian; Huang, Fu Sheng

    2013-08-01

    Blocking transmission of malaria is a reliable way to control and eliminate infection. However, in-depth knowledge of the interaction between Plasmodium and mosquito is needed. Studies suggest that innate immunity is the main mechanism inhibiting development of malaria parasites in the mosquito. Recent studies have found that use of antibiotics that inhibit the mosquito gut flora can reduce the immune response of Anopheles gambiae, thereby contributing to the development of malaria parasites. In our study, we used the non susceptible model of Anopheles dirus-Plasmodium yoelii to explore the effect of Anopheles intestinal flora on the natural resistance of A. dirus to P. yoelii. We found that in mosquitoes infected with Plasmodium, the intestinal flora can regulate expression of thioester-containing protein (TEP1) via an RNAi gene-silencing approach. Our results suggest that in the absence of TEP1, the natural microbiota cannot suppress the development of P. yoelii in A. dirus. This suggests that AdTEP1 plays an important role in the resistance of A. dirus to P. yoelii. The intestinal flora may modulate the development of P. yoelii in A. dirus by regulating TEP1 expression.

  15. Engineered anopheles immunity to Plasmodium infection.

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    Yuemei Dong

    2011-12-01

    Full Text Available A causative agent of human malaria, Plasmodium falciparum, is transmitted by Anopheles mosquitoes. The malaria parasite is under intensive attack from the mosquito's innate immune system during its sporogonic development. We have used genetic engineering to create immune-enhanced Anopheles stephensi mosquitoes through blood meal-inducible expression of a transgene encoding the IMD pathway-controlled NF-kB Rel2 transcription factor in the midgut and fat-body tissue. Transgenic mosquitoes showed greater resistance to Plasmodium and microbial infection as a result of timely concerted tissue-specific immune attacks involving multiple effectors. The relatively weak impact of this genetic modification on mosquito fitness under laboratory conditions encourages further investigation of this approach for malaria control.

  16. An expression map for Anopheles gambiae

    OpenAIRE

    MacCallum Robert M; Redmond Seth N; Christophides George K

    2011-01-01

    Abstract Background Quantitative transcriptome data for the malaria-transmitting mosquito Anopheles gambiae covers a broad range of biological and experimental conditions, including development, blood feeding and infection. Web-based summaries of differential expression for individual genes with respect to these conditions are a useful tool for the biologist, but they lack the context that a visualisation of all genes with respect to all conditions would give. For most organisms, including A....

  17. The complete mitochondrial genome of Anopheles minimus (Diptera: Culicidae) and the phylogenetics of known Anopheles mitogenomes.

    Science.gov (United States)

    Hua, Ya-Qiong; Ding, Yi-Ran; Yan, Zhen-Tian; Si, Feng-Ling; Luo, Qian-Chun; Chen, Bin

    2016-06-01

    Anopheles minimus is an important vector of human malaria in southern China and Southeast Asia. The phylogenetics of mosquitoes has not been well resolved, and the mitochondrial genome (mtgenome) has proven to be an important marker in the study of evolutionary biology. In this study, the complete mtgenome of An. minimus was sequenced for the first time. It is 15 395 bp long and encodes 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs) and a non-coding region. The gene organization is consistent with those of known Anopheles mtgenomes. The mtgenome performs a clear bias in nucleotide composition with a positive AT-skew and a negative GC-skew. All 13 PCGs prefer to use the codon UUA (Leu), ATN as initiation codon but cytochrome-oxidase subunit 1 (COI) and ND5, with TCG and GTG, and TAA as termination codon, but COI, COII, COIII and ND4, all with the incomplete T. tRNAs have the typical clover-leaf structure, but tRNA(Ser(AGN)) is consistent with known Anopheles mtgenomes. The control region includes a conserved T-stretch and a (TA)n stretch, and has the highest A+T content at 93.1%. The phylogenetics of An. minimus with 18 other Anopheles species was constructed by maximum likelihood and Bayesian inference, based on concatenated PCG sequences. The subgenera, Cellia and Anopheles, and Nyssorhynchus and Kerteszia have mutually close relationships, respectively. The Punctulatus group and Leucosphyrus group of Neomyzomyia Series, and the Albitarsis group of Albitarsis Series were suggested to be monophyletic. The monophyletic status of the subgenera, Cellia, Anopheles, Nyssorhynchus and Kerteszia need to be further elucidated.

  18. Fitness of Transgenic Anopheles stephensi Mosquitoes Expressing the SM1 Peptide under the Control of a Vitellogenin Promoter

    OpenAIRE

    Li, Chaoyang; Marrelli, Mauro T.; Yan, Guiyun; Jacobs-Lorena, Marcelo

    2008-01-01

    Three transgenic Anopheles stephensi lines were established that strongly inhibit transmission of the mouse malaria parasite Plasmodium berghei. Fitness of the transgenic mosquitoes was assessed based on life table analysis and competition experiments between transgenic and wild-type mosquitoes. Life table analysis indicated low fitness load for the 2 single-insertion transgenic mosquito lines VD35 and VD26 and no load for the double-insertion transgenic mosquito line VD9. However, in cage ex...

  19. Laboratory studies on the olfactory behaviour of Anopheles quadriannulatus

    NARCIS (Netherlands)

    Pates, H.V.; Takken, W.; Curtis, C.F.

    2005-01-01

    The host preference of Anopheles quadriannulatus Theobald (Diptera: Culicidae), the zoophilic member of the malaria mosquito complex Anopheles gambiae Giles, was investigated in a dual-choice olfactometer. Naïve female mosquitoes were exposed to CO2, acetone, 1-octen-3-ol, and skin emanations from c

  20. Population genetic structure of Anopheles arabiensis and Anopheles gambiae in a malaria endemic region of southern Tanzania

    NARCIS (Netherlands)

    K.R. Ng'habi; B.G.J. Knols; Y. Lee; H.M. Ferguson; G.C. Lanzaro

    2011-01-01

    Background: Genetic diversity is a key factor that enables adaptation and persistence of natural populations towards environmental conditions. It is influenced by the interaction of a natural population's dynamics and the environment it inhabits. Anopheles gambiae s.s. and Anopheles arabiensis are t

  1. Physico-chemical characteristics of Anopheles culicifacies and Anopheles varuna breeding water in a dry zone stream in Sri Lanka

    DEFF Research Database (Denmark)

    Piyaratne, M K; Amerasinghe, F P; Amerasinghe, P H;

    2005-01-01

    BACKGROUND & OBJECTIVES: Selected physico-chemical characteristics of flowing and pooled water in a stream that generated two malaria vectors, Anopheles culicifacies s.l. Giles and Anopheles varuna Iyengar, were investigated during August-September 1997 and July 1998 at the Upper Yan Oya watershed...

  2. Anopheles (Anopheles) Lesteri Biases and Hu (Diptera: Culicidae): Neotype Designation and Description

    Science.gov (United States)

    2005-06-30

    Anopheles) anthropoplwglts: Ma 1981: 1I (key; distribution, China: Fukien. Kiangsi. Kiangsu. Kwangsi. Kweichow. Shanghai. provinces south of Yantze River ...lowing: Taina Litwak for her illustrations; Bel Rueda, Buddy Buenavista. Lerma Bue- navista. Benjie Puma. and Modesta Coro- nado-Puma for their help in

  3. Chloroquine mediated modulation of Anopheles gambiae gene expression.

    Directory of Open Access Journals (Sweden)

    Patrícia Abrantes

    Full Text Available BACKGROUND: Plasmodium development in the mosquito is crucial for malaria transmission and depends on the parasite's interaction with a variety of cell types and specific mosquito factors that have both positive and negative effects on infection. Whereas the defensive response of the mosquito contributes to a decrease in parasite numbers during these stages, some components of the blood meal are known to favor infection, potentiating the risk of increased transmission. The presence of the antimalarial drug chloroquine in the mosquito's blood meal has been associated with an increase in Plasmodium infectivity for the mosquito, which is possibly caused by chloroquine interfering with the capacity of the mosquito to defend against the infection. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report a detailed survey of the Anopheles gambiae genes that are differentially regulated by the presence of chloroquine in the blood meal, using an A. gambiae cDNA microarray. The effect of chloroquine on transcript abundance was evaluated separately for non-infected and Plasmodium berghei-infected mosquitoes. Chloroquine was found to affect the abundance of transcripts that encode proteins involved in a variety of processes, including immunity, apoptosis, cytoskeleton and the response to oxidative stress. This pattern of differential gene expression may explain the weakened mosquito defense response which accounts for the increased infectivity observed in chloroquine-treated mosquitoes. CONCLUSIONS/SIGNIFICANCE: The results of the present study suggest that chloroquine can interfere with several putative mosquito mechanisms of defense against Plasmodium at the level of gene expression and highlight the need for a better understanding of the impacts of antimalarial agents on parasite transmission.

  4. Ecotope-Based Entomological Surveillance and Molecular Xenomonitoring of Multidrug Resistant Malaria Parasites in Anopheles Vectors

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    Prapa Sorosjinda-Nunthawarasilp

    2014-01-01

    Full Text Available The emergence and spread of multidrug resistant (MDR malaria caused by Plasmodium falciparum or Plasmodium vivax have become increasingly important in the Greater Mekong Subregion (GMS. MDR malaria is the heritable and hypermutable property of human malarial parasite populations that can decrease in vitro and in vivo susceptibility to proven antimalarial drugs as they exhibit dose-dependent drug resistance and delayed parasite clearance time in treated patients. MDR malaria risk situations reflect consequences of the national policy and strategy as this influences the ongoing national-level or subnational-level implementation of malaria control strategies in endemic GMS countries. Based on our experience along with current literature review, the design of ecotope-based entomological surveillance (EES and molecular xenomonitoring of MDR falciparum and vivax malaria parasites in Anopheles vectors is proposed to monitor infection pockets in transmission control areas of forest and forest fringe-related malaria, so as to bridge malaria landscape ecology (ecotope and ecotone and epidemiology. Malaria ecotope and ecotone are confined to a malaria transmission area geographically associated with the infestation of Anopheles vectors and particular environments to which human activities are related. This enables the EES to encompass mosquito collection and identification, salivary gland DNA extraction, Plasmodium- and species-specific identification, molecular marker-based PCR detection methods for putative drug resistance genes, and data management. The EES establishes strong evidence of Anopheles vectors carrying MDR P. vivax in infection pockets epidemiologically linked with other data obtained during which a course of follow-up treatment of the notified P. vivax patients receiving the first-line treatment was conducted. For regional and global perspectives, the EES would augment the epidemiological surveillance and monitoring of MDR falciparum and

  5. Innate immunity against malaria parasites in Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Yang Chenand; Zhi-Hui Weng; Liangbiao Zheng

    2008-01-01

    Malaria continues to exert a huge toll in the world today, causing approximately 400 million cases and killing between 1-2 million people annually. Most of the malaria burden is borne by countries in Africa. For this reason, the major vector for malaria in this continent, Anopheles gambiae, is under intense study. With the completion of the draft sequence of this important vector, efforts are underway to develop novel control strategies.One promising area is to harness the power of the innate immunity of this mosquito species to block the transmission of the malaria parasites. Recent studies have demonstrated that Toll and Imd signaling pathways and other immunity-related genes (encoding proteins possibly function in recognition or as effector molecules) play significant roles in two different arms of innate immunity: level of infection intensity and melanization of Plasmodium oocysts.The challenges in the future are to understand how the functions of these different genes are coordinated in defense against malaria parasites, and if different arms of innate immunity are cross-regulated or coordinated.

  6. Plasmodium activates the innate immune response of Anopheles gambiae mosquitoes.

    Science.gov (United States)

    Richman, A M; Dimopoulos, G; Seeley, D; Kafatos, F C

    1997-01-01

    Innate immune-related gene expression in the major disease vector mosquito Anopheles gambiae has been analyzed following infection by the malaria parasite, Plasmodium berghei. Substantially increased levels of mRNAs encoding the antibacterial peptide defensin and a putative Gram-negative bacteria-binding protein (GNBP) are observed 20-30 h after ingestion of an infected blood-meal, at a time which indicates that this induction is a response to parasite invasion of the midgut epithelium. The induction is dependent upon the ingestion of infective, sexual-stage parasites, and is not due to opportunistic co-penetration of resident gut micro-organisms into the hemocoel. The response is activated following infection both locally (in the midgut) and systemically (in remaining tissues, presumably fat body and/or hemocytes). The observation that Plasmodium can trigger a molecularly defined immune response in the vector constitutes an important advance in our understanding of parasite-vector interactions that are potentially involved in malaria transmission, and extends knowledge of the innate immune system of insects to encompass responses to protozoan parasites. PMID:9321391

  7. Distribución espacial de Anopheles pseudopunctipennis en las Yungas de Salta, Argentina Spatial distribution of Anopheles pseudopunctipennis in the Yungas de Salta rainforest, Argentina

    Directory of Open Access Journals (Sweden)

    María Julia Dantur Juri

    2005-08-01

    and abundance indices were estimated and the study sample sites were compared by ANOVA, cosine calculations and cluster analyses. RESULTS: Anopheles pseudopunctipennis was the most abundant species. An. argyritarsis, An. nuneztovari, An. rangeli and An. strodei were also collected. Except for An. nuneztovari that was not captured in the peridomiciliary area, the other species were collected in the three different environments. There were no differences in the diversity indices and between sample sites. However, the cluster analysis showed the transition area to be more abundant for all species. CONCLUSIONS: The highest abundance of species was found in the transition area, which, besides the peridomiciliary area, is the main area of risk for malarial transmission.

  8. Genetic and phenotypic variation of the malaria vector Anopheles atroparvus in southern Europe

    Directory of Open Access Journals (Sweden)

    Romi Roberto

    2011-01-01

    Full Text Available Abstract Background There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission. Methods Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatellite loci and geometric morphometrics on 21 wing landmarks. Results Levels of genetic diversity were comparable to those reported for tropical malaria vectors. Low levels of genetic (0.004 FST An. atroparvus populations spanning over 3,000 km distance. Genetic differentiation (0.202 FST An. atroparvus and Anopheles maculipennis s.s. Differentiation between sibling species was not so evident at the phenotype level. Conclusions Levels of population differentiation within An. atroparvus were low and not correlated with geographic distance or with putative physical barriers to gene flow (Alps and Pyrenées. While these results may suggest considerable levels of gene flow, other explanations such as the effect of historical population perturbations can also be hypothesized.

  9. "LABORATORY EXPERIMENTS ON THE IRRITABILITY OF ANOPHELES ATROPARVUS AND ANOPHELES STEPHENSI TO DDT "

    Directory of Open Access Journals (Sweden)

    N. Eshghy

    1977-07-01

    Full Text Available Two strains of Anopheles atroparvus, one resistant and another sceptible to DDT and two of Anopheles stephensi, one resistant and one susceptible to DDT were tested for their irritability to DDT. Various laboratory investigations of the effects of insecticides on mosquito behavior and their irritability were carried out. In these series of experiments a comparison was made between the results obtained by a tentative method proposed in 1960 by the WHO, Expert Committee on Insecticides in which the mosquitoes are confined over the treated surface in a small plastic chamber and in a large cage. Under the large cage conditions DDT-resistant A. stephensi were more readily irritated by the insecticide than a susceptible strain of the same species

  10. Genetic compatibility between Anopheles lesteri from Korea and Anopheles paraliae from Thailand

    Directory of Open Access Journals (Sweden)

    Kritsana Taai

    2013-05-01

    Full Text Available To assess differentiation and relationships between Anopheles lesteri and Anopheles paraliae we established three and five iso-female lines of An. lesteri from Korea and An. paraliae from Thailand, respectively. These isolines were used to investigate the genetic relationships between the two taxa by crossing experiments and by comparing DNA sequences of ribosomal DNA second internal transcribed spacer (ITS2 and mitochondrial DNA cytochrome c oxidase subunit I (COI and subunit II (COII. Results of reciprocal and F1-hybrid crosses between An. lesteri and An. paraliae indicated that they were compatible genetically producing viable progenies and complete synaptic salivary gland polytene chromosomes without inversion loops in all chromosome arms. The pairwise genetic distances of ITS2, COI and COII between these morphological species were 0.040, 0.007-0.017 and 0.008-0.011, respectively. The specific species status of An. paraliae in Thailand and/or other parts of the continent are discussed.

  11. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    Takken Willem

    2010-01-01

    Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

  12. Insecticide susceptibility of Anopheles coluzzii and Anopheles gambiae mosquitoes in Ibadan, Southwest Nigeria.

    Science.gov (United States)

    Okorie, P N; Ademowo, O G; Irving, H; Kelly-Hope, L A; Wondji, C S

    2015-03-01

    The emergence of insecticide resistance in Anopheles (Diptera: Culicidae) mosquitoes has great implications for malaria control in Nigeria. This study aimed to determine the dynamics of insecticide susceptibility levels and the frequency of knock-down resistance (kdr) mutations (L1014F) in wild Anopheles coluzzii Coetzee & Wilkerson sp. n. and Anopheles gambiae Giles from the Ojoo and Bodija areas of Ibadan, in southwest Nigeria. Insecticide susceptibility to pyrethroids, organophosphates, carbamates and organochlorines was assessed using World Health Organization (WHO) bioassays. A subset of the mosquitoes exposed to pyrethroids and DDT was used for species and molecular form identification; kdr genotyping was determined using the TaqMan real-time polymerase chain reaction assay. The mosquitoes were resistant to pyrethroids and DDT but completely susceptible to organophosphates and carbamates. Bodija samples (n = 186) consisted of An. gambiae (91.4%) and An. coluzzii (8.1%) and included one An. coluzzii/An. gambiae hybrid specimen. All mosquitoes screened in Ojoo (n = 26) were An. gambiae. The 1014F kdr mutation was detected at frequencies of 24.5 and 5.8% in Bodija and Ojoo, respectively. No correlation was observed between kdr genotypes and resistance phenotypes. The results indicate that metabolic resistance probably plays an important role in the development of resistance and highlight the need to implement insecticide resistance management strategies.

  13. Wide cross-reactivity between Anopheles gambiae and Anopheles funestus SG6 salivary proteins supports exploitation of gSG6 as a marker of human exposure to major malaria vectors in tropical Africa

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    Petrarca Vincenzo

    2011-07-01

    Full Text Available Abstract Background The Anopheles gambiae gSG6 is an anopheline-specific salivary protein which helps female mosquitoes to efficiently feed on blood. Besides its role in haematophagy, gSG6 is immunogenic and elicits in exposed individuals an IgG response, which may be used as indicator of exposure to the main African malaria vector A. gambiae. However, malaria transmission in tropical Africa is sustained by three main vectors (A. gambiae, Anopheles arabiensis and Anopheles funestus and a general marker, reflecting exposure to at least these three species, would be especially valuable. The SG6 protein is highly conserved within the A. gambiae species complex whereas the A. funestus homologue, fSG6, is more divergent (80% identity with gSG6. The aim of this study was to evaluate cross-reactivity of human sera to gSG6 and fSG6. Methods The A. funestus SG6 protein was expressed/purified and the humoral response to gSG6, fSG6 and a combination of the two antigens was compared in a population from a malaria hyperendemic area of Burkina Faso where both vectors were present, although with a large A. gambiae prevalence (>75%. Sera collected at the beginning and at the end of the high transmission/rainy season, as well as during the following low transmission/dry season, were analysed. Results According to previous observations, both anti-SG6 IgG level and prevalence decreased during the low transmission/dry season and showed a typical age-dependent pattern. No significant difference in the response to the two antigens was found, although their combined use yielded in most cases higher IgG level. Conclusions Comparative analysis of gSG6 and fSG6 immunogenicity to humans suggests the occurrence of a wide cross-reactivity, even though the two proteins carry species-specific epitopes. This study supports the use of gSG6 as reliable indicator of exposure to the three main African malaria vectors, a marker which may be useful to monitor malaria transmission

  14. Wolbachia infections in natural Anopheles populations affect egg laying and negatively correlate with Plasmodium development

    Science.gov (United States)

    Shaw, W. Robert; Marcenac, Perrine; Childs, Lauren M.; Buckee, Caroline O.; Baldini, Francesco; Sawadogo, Simon P.; Dabiré, Roch K.; Diabaté, Abdoulaye; Catteruccia, Flaminia

    2016-01-01

    The maternally inherited alpha-proteobacterium Wolbachia has been proposed as a tool to block transmission of devastating mosquito-borne infectious diseases like dengue and malaria. Here we study the reproductive manipulations induced by a recently identified Wolbachia strain that stably infects natural mosquito populations of a major malaria vector, Anopheles coluzzii, in Burkina Faso. We determine that these infections significantly accelerate egg laying but do not induce cytoplasmic incompatibility or sex-ratio distortion, two parasitic reproductive phenotypes that facilitate the spread of other Wolbachia strains within insect hosts. Analysis of 221 blood-fed A. coluzzii females collected from houses shows a negative correlation between the presence of Plasmodium parasites and Wolbachia infection. A mathematical model incorporating these results predicts that infection with these endosymbionts may reduce malaria prevalence in human populations. These data suggest that Wolbachia may be an important player in malaria transmission dynamics in Sub-Saharan Africa. PMID:27243367

  15. Vectors and malaria transmission in deforested, rural communities in north-central Vietnam

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    Do Manh Cuong

    2010-09-01

    Full Text Available Abstract Background Malaria is still prevalent in rural communities of central Vietnam even though, due to deforestation, the primary vector Anopheles dirus is uncommon. In these situations little is known about the secondary vectors which are responsible for maintaining transmission. Basic information on the identification of the species in these rural communities is required so that transmission parameters, such as ecology, behaviour and vectorial status can be assigned to the appropriate species. Methods In two rural villages - Khe Ngang and Hang Chuon - in Truong Xuan Commune, Quang Binh Province, north central Vietnam, a series of longitudinal entomological surveys were conducted during the wet and dry seasons from 2003 - 2007. In these surveys anopheline mosquitoes were collected in human landing catches, paired human and animal bait collections, and from larval surveys. Specimens belonging to species complexes were identified by PCR and sequence analysis, incrimination of vectors was by detection of circumsporozoite protein using an enzyme-linked immunosorbent assay. Results Over 80% of the anopheline fauna was made up of Anopheles sinensis, Anopheles aconitus, Anopheles harrisoni, Anopheles maculatus, Anopheles sawadwongporni, and Anopheles philippinensis. PCR and sequence analysis resolved identification issues in the Funestus Group, Maculatus Group, Hyrcanus Group and Dirus Complex. Most species were zoophilic and while all species could be collected biting humans significantly higher densities were attracted to cattle and buffalo. Anopheles dirus was the most anthropophilic species but was uncommon making up only 1.24% of all anophelines collected. Anopheles sinensis, An. aconitus, An. harrisoni, An. maculatus, An. sawadwongporni, Anopheles peditaeniatus and An. philippinensis were all found positive for circumsporozoite protein. Heterogeneity in oviposition site preference between species enabled vector densities to be high in both

  16. Ecology and behavior of Anopheles arabiensis in relation to agricultural practices in central Kenya.

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    Muturi, Ephantus J; Mwangangi, Joseph M; Beier, John C; Blackshear, Millon; Wauna, James; Sang, Rosemary; Mukabana, Wolfgang R

    2013-09-01

    Ecological changes associated with anthropogenic ecosystem disturbances can influence human risk of exposure to malaria and other vector-borne infectious diseases. This study in Mwea, Kenya, investigated the pattern of insecticide use in irrigated and nonirrigated agroecosystems and association with the density, survival, and blood-feeding behavior of the malaria vector Anopheles arabiensis. The parity rates of adult An. arabiensis from randomly selected houses were determined by examining their ovaries for tracheal distension, and polymerase chain reaction was used to identify the host blood meals. In addition, structured questionnaires were used to generate data on insecticide use. Anopheles arabiensis densities were highest in irrigated rice agroecosystems, intermediate in irrigated French beans agroecosystems, and lowest in the nonirrigated agroecosystem. Anopheles arabiensis adult survivorship was significantly lower in irrigated rice agroecosystems than in irrigated French beans agroecosystems. The human blood index (HBI) was significantly higher in the nonirrigated agroecosystem compared to irrigated agroecosystems. Moreover, there was marked variation in HBI among villages in irrigated agroecosystems with significantly lower HBI in Kangichiri and Mathangauta compared to Kiuria, Karima, and Kangai. The proportion of mosquitoes with mixed blood meals varied among villages ranging from 0.25 in Kangichiri to 0.83 in Kiuria. Sumithion, dimethoate, and alpha cypermethrin were the most commonly used insecticides. The 1st was used mostly in irrigated rice agroecosystems, and the last 2 were used mostly in irrigated French beans agroecosystems. These findings indicate that agricultural practices may influence the ecology and behavior of malaria vectors and ultimately the risk of malaria transmission.

  17. Spatio-temporal variations of Anopheles coluzzii and An. gambiae and their Plasmodium infectivity rates in Lobito, Angola.

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    Carnevale, Pierre; Toto, Jean-Claude; Besnard, Patrick; Santos, Maria Adelaide Dos; Fortes, Filomeno; Allan, Richard; Manguin, Sylvie

    2015-06-01

    From 2003 to 2007, entomological surveys were conducted in Lobito town (Benguela Province, Angola) to determine which Anopheles species were present and to identify the vectors responsible for malaria transmission in areas where workers of the Sonamet Company live. Two types of surveys were conducted: (1) time and space surveys in the low and upper parts of Lobito during the rainy and dry periods; (2) a two-year longitudinal study in Sonamet workers' houses provided with long-lasting insecticide-treated nets (LLIN), "PermaNet," along with the neighboring community. Both species, An. coluzzii (M molecular form) and An. gambiae (S molecular form), were collected. Anopheles coluzzii was predominant during the dry season in the low part of Lobito where larvae develop in natural ponds and temporary pools. However, during the rainy season, An. gambiae was found in higher proportions in the upper part of the town where larvae were collected in domestic water tanks built near houses. Anopheles melas and An. listeri were captured in higher numbers during the dry season and in the low part of Lobito where larvae develop in stagnant brackish water pools. The infectivity rates of An. gambiae s.l. varied from 0.90% to 3.41%.

  18. Unexpected diversity of Anopheles species in Eastern Zambia: implications for evaluating vector behavior and interventions using molecular tools.

    Science.gov (United States)

    Lobo, Neil F; St Laurent, Brandyce; Sikaala, Chadwick H; Hamainza, Busiku; Chanda, Javan; Chinula, Dingani; Krishnankutty, Sindhu M; Mueller, Jonathan D; Deason, Nicholas A; Hoang, Quynh T; Boldt, Heather L; Thumloup, Julie; Stevenson, Jennifer; Seyoum, Aklilu; Collins, Frank H

    2015-12-09

    The understanding of malaria vector species in association with their bionomic traits is vital for targeting malaria interventions and measuring effectiveness. Many entomological studies rely on morphological identification of mosquitoes, limiting recognition to visually distinct species/species groups. Anopheles species assignments based on ribosomal DNA ITS2 and mitochondrial DNA COI were compared to morphological identifications from Luangwa and Nyimba districts in Zambia. The comparison of morphological and molecular identifications determined that interpretations of species compositions, insecticide resistance assays, host preference studies, trap efficacy, and Plasmodium infections were incorrect when using morphological identification alone. Morphological identifications recognized eight Anopheles species while 18 distinct sequence groups or species were identified from molecular analyses. Of these 18, seven could not be identified through comparison to published sequences. Twelve of 18 molecularly identified species (including unidentifiable species and species not thought to be vectors) were found by PCR to carry Plasmodium sporozoites - compared to four of eight morphological species. Up to 15% of morphologically identified Anopheles funestus mosquitoes in insecticide resistance tests were found to be other species molecularly. The comprehension of primary and secondary malaria vectors and bionomic characteristics that impact malaria transmission and intervention effectiveness are fundamental in achieving malaria elimination.

  19. A High-Affinity Adenosine Kinase from Anopheles Gambiae

    Energy Technology Data Exchange (ETDEWEB)

    M Cassera; M Ho; E Merino; E Burgos; A Rinaldo-Matthis; S Almo; V Schramm

    2011-12-31

    Genome analysis revealed a mosquito orthologue of adenosine kinase in Anopheles gambiae (AgAK; the most important vector for the transmission of Plasmodium falciparum in Africa). P. falciparum are purine auxotrophs and do not express an adenosine kinase but rely on their hosts for purines. AgAK was kinetically characterized and found to have the highest affinity for adenosine (K{sub m} = 8.1 nM) of any known adenosine kinase. AgAK is specific for adenosine at the nucleoside site, but several nucleotide triphosphate phosphoryl donors are tolerated. The AgAK crystal structure with a bound bisubstrate analogue Ap{sub 4}A (2.0 {angstrom} resolution) reveals interactions for adenosine and ATP and the geometry for phosphoryl transfer. The polyphosphate charge is partly neutralized by a bound Mg{sup 2+} ion and an ion pair to a catalytic site Arg. The AgAK structure consists of a large catalytic core in a three-layer {alpha}/{beta}/{alpha} sandwich, and a small cap domain in contact with adenosine. The specificity and tight binding for adenosine arise from hydrogen bond interactions of Asn14, Leu16, Leu40, Leu133, Leu168, Phe168, and Thr171 and the backbone of Ile39 and Phe168 with the adenine ring as well as through hydrogen bond interactions between Asp18, Gly64, and Asn68 and the ribosyl 2'- and 3'-hydroxyl groups. The structure is more similar to that of human adenosine kinase (48% identical) than to that of AK from Toxoplasma gondii (31% identical). With this extraordinary affinity for AgAK, adenosine is efficiently captured and converted to AMP at near the diffusion limit, suggesting an important role for this enzyme in the maintenance of the adenine nucleotide pool. mRNA analysis verifies that AgAK transcripts are produced in the adult insects.

  20. Spermless males elicit large-scale female responses to mating in the malaria mosquito Anopheles gambiae

    Science.gov (United States)

    Thailayil, Janis; Magnusson, Kalle; Godfray, H. Charles J.; Crisanti, Andrea; Catteruccia, Flaminia

    2011-01-01

    Anopheles gambiae sensu stricto is the major vector of malaria, a disease with devastating consequences for human health. Given the constant spread of the disease, alternative approaches to the use of insecticides are urgently needed to control vector populations. Females of this species undergo large behavioral changes after mating, which include a life-long refractoriness to further insemination and the induction of egg laying in blood-fed individuals. Genetic control strategies aimed at impacting Anopheles fertility through the release of sterile males are being advocated to reduce the size of mosquito field populations. Such strategies depend on the ability of the released sterile males to mate successfully with wild females and to switch off the female receptivity to further copulation. Here we evaluate the role of sperm in regulating female behavioral responses after mating in An. gambiae. We developed spermless males by RNAi silencing of a germ cell differentiation gene. These males mated successfully and preserved standard accessory gland functions. Females mated to spermless males exhibited normal postcopulatory responses, which included laying large numbers of eggs upon blood feeding and becoming refractory to subsequent insemination. Moreover, spermless males induced transcriptional changes in female reproductive genes comparable to those elicited by fertile males. Our data demonstrate that, in contrast to Drosophila, targeting sperm in An. gambiae preserves normal male and female reproductive behavior for the traits and time frame analyzed and validate the use of approaches based on incapacitation or elimination of sperm for genetic control of vector populations to block malaria transmission. PMID:21825136

  1. A natural Anopheles-associated Penicillium chrysogenum enhances mosquito susceptibility to Plasmodium infection

    Science.gov (United States)

    Angleró-Rodríguez, Yesseinia I.; Blumberg, Benjamin J.; Dong, Yuemei; Sandiford, Simone L.; Pike, Andrew; Clayton, April M.; Dimopoulos, George

    2016-01-01

    Whereas studies have extensively examined the ability of bacteria to influence Plasmodium infection in the mosquito, the tripartite interactions between non-entomopathogenic fungi, mosquitoes, and Plasmodium parasites remain largely uncharacterized. Here we report the isolation of a common mosquito-associated ascomycete fungus, Penicillium chrysogenum, from the midgut of field-caught Anopheles mosquitoes. Although the presence of Pe. chrysogenum in the Anopheles gambiae midgut does not affect mosquito survival, it renders the mosquito significantly more susceptible to Plasmodium infection through a secreted heat-stable factor. We further provide evidence that the mechanism of the fungus-mediated modulation of mosquito susceptibility to Plasmodium involves an upregulation of the insect’s ornithine decarboxylase gene, which sequesters arginine for polyamine biosynthesis. Arginine plays an important role in the mosquito’s anti-Plasmodium defense as a substrate of nitric oxide production, and its availability therefore has a direct impact on the mosquito’s susceptibility to the parasite. While this type of immunomodulatory mechanism has already been demonstrated in other host-pathogen interaction systems, this is the first report of a mosquito-associated fungus that can suppress the mosquito’s innate immune system in a way that would favor Plasmodium infection and possibly malaria transmission. PMID:27678168

  2. Distribution of the species of the Anopheles gambiae complex and first evidence of Anopheles merus as a malaria vector in Madagascar

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    Le Goff Gilbert

    2003-10-01

    Full Text Available Abstract Background Members of the Anopheles gambiae complex are amongst the best malaria vectors in the world, but their vectorial capacities vary between species and populations. A large-scale sampling of An. gambiae sensu lato was carried out in various bioclimatic domains of Madagascar. Local abundance of an unexpected member of this complex raised questions regarding its role in malaria transmission. Methods Sampling took place at 38 sites and 2,067 females were collected. Species assessment was performed using a PCR targeting a sequence in the IGS of the rDNA. Analysis focused on the relative prevalence of the species per site, bioclimatic domain and altitude. Infectivity of Anopheles merus was assessed using an ELISA to detect the presence of malarial circumsporozoite protein in the head-thorax. Results Three species were identified: An. gambiae, Anopheles arabiensis and An. merus. The distribution of each species is mainly a function of bioclimatic domains and, to a lesser extent, altitude. An. arabiensis is present in all bioclimatic domains with highest prevalence in sub-humid, dry and sub-arid domains. An. gambiae has its highest prevalence in the humid domain, is in the minority in dry areas, rare in sub-humid and absent in sub-arid domains. An. merus is restricted to the coastal fringe in the south and west; it was in the majority in one southern village. The majority of sites were sympatric for at least two of the species (21/38 and two sites harboured all three species. The role of An. merus as malaria vector was confirmed in the case of two human-biting females, which were ELISA-positive for Plasmodium falciparum. Conclusion Despite the huge environmental (mainly man-made changes in Madagascar, the distribution of An. gambiae and An. arabiensis appears unchanged for the past 35 years. The distribution of An. merus is wider than was previously known, and its effectiveness as a malaria vector has been shown for the first time; this

  3. Composition of Anopheles coluzzii and Anopheles gambiae microbiota from larval to adult stages.

    Science.gov (United States)

    Gimonneau, Geoffrey; Tchioffo, Majoline T; Abate, Luc; Boissière, Anne; Awono-Ambéné, Parfait H; Nsango, Sandrine E; Christen, Richard; Morlais, Isabelle

    2014-12-01

    During their immature life stages, malaria mosquitoes are exposed to a wide array of microbes and contaminants from the aquatic habitats. Although prior studies have suggested that environmental exposure shapes the microbial community structure in the adult mosquito, most reports have focused on laboratory-based experiments and on a single mosquito epithelium, the gut. In this study, we investigated the influence of the breeding site on the development of the Anopheles coluzzii and Anopheles gambiae microbiota in natural conditions. We characterized bacterial communities from aquatic habitats, at surface microlayer and subsurface water levels, to freshly emerge adult mosquitoes using multiplexed 16S rRNA gene pyrosequencing and we separately analyzed the microbiota associated with the different epithelia of adult individual, midguts, ovaries and salivary glands. We found that the distribution of bacterial communities in the aquatic habitats differed according to the depth of water collections. Inter-individual variation of bacterial composition was large in larvae guts but adult mosquitoes from a same breeding site shared quite similar microbiota. Although some differences in bacterial abundances were highlighted between the different epithelia of freshly emerged An. coluzzii and An. gambiae, an intriguing feature from our study is the particular similarity of the overall bacterial communities. Our results call for further investigations on the bacterial population dynamics in the different tissues to determine the distinctive characteristics of each microbiota during the mosquito lifespan and to identify specific interactions between certain key phyla or species and the insect life history traits.

  4. Susceptibility of Anopheles gambiae and Anopheles stephensi to tropical isolates of Plasmodium falciparum

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    Ranford-Cartwright Lisa C

    2007-10-01

    Full Text Available Abstract Background The susceptibility of anopheline mosquito species to Plasmodium infection is known to be variable with some mosquitoes more permissive to infection than others. Little work, however, has been carried out investigating the susceptibility of major malaria vectors to geographically diverse tropical isolates of Plasmodium falciparum aside from examining the possibility of infection extending its range from tropical regions into more temperate zones. Methods This study investigates the susceptibility of two major tropical mosquito hosts (Anopheles gambiae and Anopheles stephensi to P. falciparum isolates of different tropical geographical origins. Cultured parasite isolates were fed via membrane feeders simultaneously to both mosquito species and the resulting mosquito infections were compared. Results Infection prevalence was variable with African parasites equally successful in both mosquito species, Thai parasites significantly more successful in An. stephensi, and PNG parasites largely unsuccessful in both species. Conclusion Infection success of P. falciparum was variable according to geographical origin of both the parasite and the mosquito. Data presented raise the possibility that local adaptation of tropical parasites and mosquitoes has a role to play in limiting gene flow between allopatric parasite populations.

  5. Engineered resistance to Plasmodium falciparum development in transgenic Anopheles stephensi.

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    Alison T Isaacs

    2011-04-01

    Full Text Available Transposon-mediated transformation was used to produce Anopheles stephensi that express single-chain antibodies (scFvs designed to target the human malaria parasite, Plasmodium falciparum. The scFvs, m1C3, m4B7, and m2A10, are derived from mouse monoclonal antibodies that inhibit either ookinete invasion of the midgut or sporozoite invasion of salivary glands. The scFvs that target the parasite surface, m4B7 and m2A10, were fused to an Anopheles gambiae antimicrobial peptide, Cecropin A. Previously-characterized Anopheles cis-acting DNA regulatory elements were included in the transgenes to coordinate scFv production with parasite development. Gene amplification and immunoblot analyses showed promoter-specific increases in transgene expression in blood-fed females. Transgenic mosquito lines expressing each of the scFv genes had significantly lower infection levels than controls when challenged with P. falciparum.

  6. Bionomics of Anopheles spp. (Diptera: Culicidae) in a malaria endemic region of Sukabumi, West Java, Indonesia.

    Science.gov (United States)

    Stoops, Craig A; Rusmiarto, Saptoro; Susapto, Dwiko; Munif, Amurl; Andris, Heri; Barbara, Kathryn A; Sukowati, Supratman

    2009-12-01

    A 15-month bionomic study of Anopheles species was conducted in two ecologically distinct villages (coastal and upland) of Sukabumi District, West Java, Indonesia from June 2006 to September 2007. Mosquitoes were captured using human-landing collections at both sites. During the study, a total of 17,100 Anopheles mosquitoes comprising 13 Anopheles species were caught: 9,151 at the coastal site and 7,949 at the upland site. Anopheles barbirostris, Anopheles maculatus, and Anopheles vagus were the predominant species caught at the coastal site, and Anopheles aconitus, Anopheles barbirostris, and An. maculatus predominated in the upland site. Overall, species were exophagic at both sites, but there was variation between species. Anopheles aconitus was endophagic at the coastal site, exophagic at the upland site, collected most often in April 2007 and had a peak landing time between 22:00 and 23:00. Anopheles sundaicus was only collected at the coastal site, exophagic, collected most often in October 2006, and had a peak landing time between 19:00 and 20:00. Potential malaria vector species such An. aconitus, An. maculatus, and An. sundaicus were present throughout the year. None of the 7,770 Anopheles tested using CSP-ELISA were positive for malaria, although the risk for malaria outbreaks in Sukabumi district remains high.

  7. Mermithid nematodes found in adult Anopheles from southeastern Senegal

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    Kobylinski Kevin C

    2012-06-01

    Full Text Available Abstract Background Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population. Methods Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18 S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18 S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family. Results The mermithid was present in 1.8% (10/551 of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus. Conclusions To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal

  8. Anopheles plumbeus (Diptera: Culicidae in Europe: a mere nuisance mosquito or potential malaria vector?

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    Schaffner Francis

    2012-11-01

    Full Text Available Abstract Background Anopheles plumbeus has been recognized as a minor vector for human malaria in Europe since the beginning of the 20th century. In recent years this tree hole breeding mosquito species appears to have exploited novel breeding sites, including large and organically rich man-made containers, with consequently larger mosquito populations in close vicinity to humans. This lead to investigate whether current populations of An. plumbeus would be able to efficiently transmit Plasmodium falciparum, the parasite responsible for the most deadly form of malaria. Methods Anopheles plumbeus immatures were collected from a liquid manure pit in Switzerland and transferred as adults to the CEPIA (Institut Pasteur, France where they were fed on P. falciparum gametocytes produced in vitro. Anopheles gambiae mosquitoes served as controls. Development of P. falciparum in both mosquito species was followed by microscopical detection of oocysts on mosquito midguts and by sporozoite detection in the head/thorax by PCR and microscopy. Results A total of 293 wild An. plumbeus females from four independent collections successfully fed through a membrane on blood containing P. falciparum gametocytes. Oocysts were observed in mosquito midguts and P. falciparum DNA was detected in head-thorax samples in all four experiments, demonstrating, on a large mosquito sample, that An. plumbeus is indeed receptive to P. falciparum NF54 and able to produce sporozoites. Importantly, the proportion of sporozoites-infected An. plumbeus was almost similar to that of An. gambiae (31 to 88% An. plumbeus versus 67 to 97% An. gambiae. However, the number of sporozoites produced was significantly lower in infected An. plumbeus. Conclusion The results show that a sample of field-caught An. plumbeus has a moderate to high receptivity towards P. falciparum. Considering the increased mobility of humans between Europe and malaria endemic countries and changes in environment and

  9. Amazon Anopheles Biology. 12. Occurrence of Anopheles Species, Malaria Control and Transmission Dynamics in the Urban Zone of Ariquemes (Rondonia)

    Science.gov (United States)

    1988-01-01

    anophelines collected were captured at this site. In view of this characteris- 21 tic , Gurgel was designated a Collection Station, and samplings were taken...Diptera-Culicidae): sua importancia na transmissdo da maldria. Contribution toward understanding of the species of the Kertszia subgenus (Diptera...R.G. & MARQUES, A.P. - Algumas obser- vag6es sobre a biologia dos anofelinos de importancia epidemiol6- gica de Beldm, Par&. Some observations on

  10. Genetic diversity and gene flow of humans, Plasmodium falciparum, and Anopheles farauti s.s. of Vanuatu: inferred malaria dispersal and implications for malaria control.

    Science.gov (United States)

    Lum, J K; Kaneko, A; Taleo, G; Amos, M; Reiff, D M

    2007-08-01

    A comparison of the patterns of gene flow within and between islands and the genetic diversities of the three species required for malaria transmission (humans, Plasmodium falciparum, and Anopheles farauti s.s.) within the model island system of Vanuatu, shows that the active dispersal of An. farauti s.s. is responsible for within island movement of parasites. In contrast, since both P. falciparum and An. farauti s.s. populations are largely restricted to islands, movement of parasites between islands is likely due to human transport. Thus, control of vectors is crucial for controlling malaria within islands, while control of human movement is essential to control malaria transmission across the archipelago.

  11. Morphology of the larvae, male genitalia and DNA sequences of Anopheles (Kerteszia pholidotus (Diptera: Culicidae from Colombia

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    Jesús Eduardo Escovar

    2014-07-01

    Full Text Available Since 1984, Anopheles (Kerteszia lepidotus has been considered a mosquito species that is involved in the transmission of malaria in Colombia, after having been incriminated as such with epidemiological evidence from a malaria outbreak in Cunday-Villarrica, Tolima. Subsequent morphological analyses of females captured in the same place and at the time of the outbreak showed that the species responsible for the transmission was not An. lepidotus, but rather Anopheles pholidotus. However, the associated morphological stages and DNA sequences of An. pholidotus from the foci of Cunday-Villarrica had not been analysed. Using samples that were caught recently from the outbreak region, the purpose of this study was to provide updated and additional information by analysing the morphology of female mosquitoes, the genitalia of male mosquitoes and fourth instar larvae of An. pholidotus, which was confirmed with DNA sequences of cytochrome oxidase I and rDNA internal transcribed spacer. A total of 1,596 adult females were collected in addition to 37 larval collections in bromeliads. Furthermore, 141 adult females, which were captured from the same area in the years 1981-1982, were analysed morphologically. Ninety-five DNA sequences were analysed for this study. Morphological and molecular analyses showed that the species present in this region corresponds to An. pholidotus. Given the absence of An. lepidotus, even in recent years, we consider that the species of mosquitoes that was previously incriminated as the malaria vector during the outbreak was indeed An. pholidotus, thus ending the controversy.

  12. The evolution of the Anopheles 16 genomes project

    NARCIS (Netherlands)

    Neafsey, Daniel E.; Christophides, George K.; Collins, Frank H.; Emrich, Scott J.; Fontaine, Michael C.; Gelbart, William; Hahn, Matthew W.; Howell, Paul I.; Kafatos, Fotis C.; Lawson, Daniel; Muskavitch, Marc A. T.; Waterhouse, Robert M.; Williams, Louise J.; Besansky, Nora J.

    2013-01-01

    We report the imminent completion of a set of reference genome assemblies for 16 species of Anopheles mosquitoes. In addition to providing a generally useful resource for comparative genomic analyses, these genome sequences will greatly facilitate exploration of the capacity exhibited by some Anophe

  13. Cannibalism and predation among larvae of the Anopheles gambiae complex

    NARCIS (Netherlands)

    Koenraadt, C.J.M.; Takken, W.

    2003-01-01

    Among the aquatic developmental stages of the Anopheles gambiae complex (Diptera: Culicidae), both inter- and intra-specific interactions influence the resulting densities of adult mosquito populations. For three members of the complex, An. arabiensis Patton, An. quadriannulatus (Theobald) and An. g

  14. Ecology of Anopheles spp. in Central Lombok Regency

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    Majematang Mading

    2014-06-01

    Full Text Available Malaria remains a public health problem in West Nusa Tenggara Province. Central Lombok District is one of the areas with high case of malaria. Annual Malaria Incidence (AMI was increased from 5.9 ‰ in 2006, 6.7‰ up to 8.1‰ in 2008. The objective of the study is to describe the ecological condition of Anopheles spp. through observation, measurement of environmental variables, larvae and adult collection. This research was an observational research with cross-sectional study. The population of this study is all mosquitos and breeding habitats of Anopheles spp. that exist in the research location. Ecological observations carried out on anopheles breeding habitats including acidity, salinity, shaded places and aquatic biota. Air temperature and humidity measured at the adult mosquitoes trapping sites. The result showed that pH values of water is around 9.00, salinity in the breeding habitats around 14 ppm, and water biota (i.e. moss, grass, shrimps, fishes, tadpoles and crabs surrounded by bushes with larvae density 0,1-28,8 each dipping. The air measurement at the time was between 23°-27° Celsius and 65%-84% humidity. This research concludes that ecology and environmental conditions were supporting the development of larvae and adult mosquito of Anopheles spp.

  15. Description of the egg of Anopheles (Anopheles intermedius (Peryassu, 1908 (Diptera: Culicidae by scanning electron microscopy

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    Oswaldo Paulo Forattini

    1997-01-01

    Full Text Available The egg of Anopheles (Anopheles intermedius (Peryassu, 1908 is described and illustrated with scanning electron micrographs. Literature data on An. (Ano. maculipes (Theobald, 1903 is providedOs ovos de An. intermedius foram descritos e ilustrados por Costa Lima (1929. Este autor, baseando-se nos desenhos de Peryassu (1908 para An. maculipes, chamou atenção para o fato do ovo desta espécie ser semelhante ao de An. maculipes. Posteriormente, Causey e col. (1944, estudando os ovos de An. intermedius e An. maculipes ao estereomicroscópio, diferenciou-os por caracteres da franja. Em An. intermedius a franja é oblíqua ao eixo longitudinal do ovo, mas perpendicular em An. maculipes. Causey e col. (1944 ilustraram as variações morfológicas que encontraram na franja do ovo de An. intermedius. Os autores observaram que a franja apresentava-se descotínua em alguns espécimens de An. intermedius, tornando-se em pequenos círculos nessa região. Embora semelhante ao de An. maculipes, os ovos de An. intermedius podem ser facilmente reconhecidos por características da franja, flutuadores e tubérculos lobados, como pode ser observado na descrição. Contudo, será necessário estudar a morfologia dos ovos de outras espécies do subgênero para que se possa estabelecer as diferenças e fazer comparações precisas entre as espécies

  16. Anopheles culicifacies: siblings species composition and its relationship to malaria incidence.

    Science.gov (United States)

    Subbarao, S K; Vasantha, K; Raghavendra, K; Sharma, V P; Sharma, G K

    1988-03-01

    Entomological and epidemiological surveys in May, August and November 1985 and March 1986 were conducted in villages in Bulandshahr, a western district in Uttar Pradesh and in three eastern districts, Jaunpur, Ballia and Saran. In Bulandshahr, Anopheles culicifacies sibling species A and B were found, with a predominance of species A. Both Plasmodium vivax and P. falciparum were present and the malaria incidence remained high (SPR, 6-50%) indicating an active transmission. In contrast, in three eastern districts predominance of species B with an occasional occurrence of species A was observed. Malaria cases were almost absent in Ballia and Saran and in Jaunpur 10.3% slide positivity rate was observed in May but in later surveys cases were considerably lower (SPR, 0.5-2.9%) indicating the absence of indigenous transmission. In the eastern districts, malaria parasites are regularly brought in from endemic areas by the migrant labor population. Although An. culicifacies s.l. occurs in both the areas, the difference in malaria incidence appears to be due to the difference in the composition of the sibling species which is, the predominant presence of species A in the western district and its absence in eastern districts. This indicates that species A is responsible for active malaria transmission while species B is not.

  17. The transmembrane isoform of Plasmodium falciparum MAEBL is essential for the invasion of Anopheles salivary glands.

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    Fabian E Saenz

    Full Text Available Malaria transmission depends on infective stages in the mosquito salivary glands. Plasmodium sporozoites that mature in midgut oocysts must traverse the hemocoel and invade the mosquito salivary glands in a process thought to be mediated by parasite ligands. MAEBL, a homologue of the transmembrane EBP ligands essential in merozoite invasion, is expressed abundantly in midgut sporozoites. Alternative splicing generates different MAEBL isoforms and so it is unclear what form is functionally essential. To identify the MAEBL isoform required for P. falciparum (NF54 sporozoite invasion of salivary glands, we created knockout and allelic replacements each carrying CDS of a single MAEBL isoform. Only the transmembrane form of MAEBL is essential and is the first P. falciparum ligand validated as essential for invasion of Anopheles salivary glands. MAEBL is the first P. falciparum ligand experimentally determined to be essential for this important step in the life cycle where the vector becomes infectious for transmitting sporozoites to people. With an increasing emphasis on advancing vector-based transgenic methods for suppression of malaria, it is important that this type of study, using modern molecular genetic tools, is done with the agent of the human disease. Understanding what P. falciparum sporozoite ligands are critical for mosquito transmission will help validate targets for vector-based transmission-blocking strategies.

  18. Urban agriculture and Anopheles habitats in Dar es Salaam, Tanzania

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    Stefan Dongus

    2009-05-01

    Full Text Available A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban Dar es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2 was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92. Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in Dar es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.

  19. Urban agriculture and Anopheles habitats in Dar es Salaam, Tanzania.

    Science.gov (United States)

    Dongus, Stefan; Nyika, Dickson; Kannady, Khadija; Mtasiwa, Deo; Mshinda, Hassan; Gosoniu, Laura; Drescher, Axel W; Fillinger, Ulrike; Tanner, Marcel; Killeen, Gerry F; Castro, Marcia C

    2009-05-01

    A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban Dar es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2) was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92). Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in Dar es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.

  20. Molecular confirmation of the occurrence in Germany of Anopheles daciae (Diptera, Culicidae

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    Kronefeld Mandy

    2012-11-01

    Full Text Available Abstract Background Anopheles daciae, a newly described member of the Maculipennis group, was recently reported from western, southern and eastern Europe. Before its recognition, it had commonly been listed under the name of An. messeae, due to its extreme morphological and genetic similarities. As the sibling species of the Maculipennis group are known to differ in their vector competences for malaria parasites and other pathogens, the occurrence of An. daciae in a given region might have an impact on the epidemiology of mosquito-borne diseases. Mosquito collections from different localities in Germany were therefore screened for An. daciae. Methods Adult and immature Maculipennis group mosquitoes were collected between May 2011 and June 2012 at 23 different sites in eight federal states of Germany. A standard PCR assay was used to differentiate the previously known sibling species while the ITS2 rDNA of specimens preliminarily identified as An. messeae/daciae was sequenced and analysed for species-specific nucleotide differences. Results Four hundred and seventy-seven Anopheles specimens were successively identified to Maculipennis group level by morphology and to species level by DNA-based methods. Four species of the Maculipennis group were registered: An. messeae (n = 384, An. maculipennis (n = 82, An. daciae (n = 10 and An. atroparvus (n = 1. Anopheles daciae occurred at four sites in three federal states of Germany, three of the sites being located in north-eastern Germany (federal states of Brandenburg and Saxony while one collection site was situated in the northern Upper Rhine Valley in the federal state of Hesse, south-western Germany. Conclusions The detection of An. daciae represents the first recognition of this species in Germany where it was found to occur in sympatry with An. messeae and An. maculipennis. As the collection sites were in both north-eastern and south-western parts of Germany, the species is

  1. Genomic islands of speciation in Anopheles gambiae.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available The African malaria mosquito, Anopheles gambiae sensu stricto (A. gambiae, provides a unique opportunity to study the evolution of reproductive isolation because it is divided into two sympatric, partially isolated subtaxa known as M form and S form. With the annotated genome of this species now available, high-throughput techniques can be applied to locate and characterize the genomic regions contributing to reproductive isolation. In order to quantify patterns of differentiation within A. gambiae, we hybridized population samples of genomic DNA from each form to Affymetrix GeneChip microarrays. We found that three regions, together encompassing less than 2.8 Mb, are the only locations where the M and S forms are significantly differentiated. Two of these regions are adjacent to centromeres, on Chromosomes 2L and X, and contain 50 and 12 predicted genes, respectively. Sequenced loci in these regions contain fixed differences between forms and no shared polymorphisms, while no fixed differences were found at nearby control loci. The third region, on Chromosome 2R, contains only five predicted genes; fixed differences in this region were also verified by direct sequencing. These "speciation islands" remain differentiated despite considerable gene flow, and are therefore expected to contain the genes responsible for reproductive isolation. Much effort has recently been applied to locating the genes and genetic changes responsible for reproductive isolation between species. Though much can be inferred about speciation by studying taxa that have diverged for millions of years, studying differentiation between taxa that are in the early stages of isolation will lead to a clearer view of the number and size of regions involved in the genetics of speciation. Despite appreciable levels of gene flow between the M and S forms of A. gambiae, we were able to isolate three small regions of differentiation where genes responsible for ecological and behavioral

  2. Anopheles gambiae immune responses to human and rodent Plasmodium parasite species.

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    Yuemei Dong

    2006-06-01

    Full Text Available Transmission of malaria is dependent on the successful completion of the Plasmodium lifecycle in the Anopheles vector. Major obstacles are encountered in the midgut tissue, where most parasites are killed by the mosquito's immune system. In the present study, DNA microarray analyses have been used to compare Anopheles gambiae responses to invasion of the midgut epithelium by the ookinete stage of the human pathogen Plasmodium falciparum and the rodent experimental model pathogen P. berghei. Invasion by P. berghei had a more profound impact on the mosquito transcriptome, including a variety of functional gene classes, while P. falciparum elicited a broader immune response at the gene transcript level. Ingestion of human malaria-infected blood lacking invasive ookinetes also induced a variety of immune genes, including several anti-Plasmodium factors. Twelve selected genes were assessed for effect on infection with both parasite species and bacteria using RNAi gene silencing assays, and seven of these genes were found to influence mosquito resistance to both parasite species. An MD2-like receptor, AgMDL1, and an immunolectin, FBN39, showed specificity in regulating only resistance to P. falciparum, while the antimicrobial peptide gambicin and a novel putative short secreted peptide, IRSP5, were more specific for defense against the rodent parasite P. berghei. While all the genes that affected Plasmodium development also influenced mosquito resistance to bacterial infection, four of the antimicrobial genes had no effect on Plasmodium development. Our study shows that the impact of P. falciparum and P. berghei infection on A. gambiae biology at the gene transcript level is quite diverse, and the defense against the two Plasmodium species is mediated by antimicrobial factors with both universal and Plasmodium-species specific activities. Furthermore, our data indicate that the mosquito is capable of sensing infected blood constituents in the absence

  3. Spatial and sex-specific dissection of the Anopheles gambiae midgut transcriptome

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    Mahairaki Vassiliki

    2007-01-01

    Full Text Available Abstract Background The midgut of hematophagous insects, such as disease transmitting mosquitoes, carries out a variety of essential functions that mostly relate to blood feeding. The midgut of the female malaria vector mosquito Anopheles gambiae is a major site of interactions between the parasite and the vector. Distinct compartments and cell types of the midgut tissue carry out specific functions and vector borne pathogens interact and infect different parts of the midgut. Results A microarray based global gene expression approach was used to compare transcript abundance in the four major female midgut compartments (cardia, anterior, anterior part of posterior and posterior part of posterior midgut and between the male and female Anopheles gambiae midgut. Major differences between the female and male midgut gene expression relate to digestive processes and immunity. Each compartment has a distinct gene function profile with the posterior midgut expressing digestive enzyme genes and the cardia and anterior midgut expressing high levels of antimicrobial peptide and other immune gene transcripts. Interestingly, the cardia expressed several known anti-Plasmodium factors. A parallel peptidomic analysis of the cardia identified known mosquito antimicrobial peptides as well as several putative short secreted peptides that are likely to represent novel antimicrobial factors. Conclusion The A. gambiae sex specific midgut and female midgut compartment specific transcriptomes correlates with their known functions. The significantly greater functional diversity of the female midgut relate to hematophagy that is associated with digestion and nutrition uptake as well as exposes it to a variety of pathogens, and promotes growth of its endogenous microbial flora. The strikingly high proportion of immunity related factors in the cardia tissue most likely serves the function to increase sterility of ingested sugar and blood. A detailed characterization of the

  4. Climate, environment and transmission of malaria.

    Science.gov (United States)

    Rossati, Antonella; Bargiacchi, Olivia; Kroumova, Vesselina; Zaramella, Marco; Caputo, Annamaria; Garavelli, Pietro Luigi

    2016-06-01

    Malaria, the most common parasitic disease in the world, is transmitted to the human host by mosquitoes of the genus Anopheles. The transmission of malaria requires the interaction between the host, the vector and the parasite.The four species of parasites responsible for human malaria are Plasmodium falciparum, Plasmodium ovale, Plasmodium malariae and Plasmodium vivax. Occasionally humans can be infected by several simian species, like Plasmodium knowlesi, recognised as a major cause of human malaria in South-East Asia since 2004. While P. falciparum is responsible for most malaria cases, about 8% of estimated cases globally are caused by P. vivax. The different Plasmodia are not uniformly distributed although there are areas of species overlap. The life cycle of all species of human malaria parasites is characterised by an exogenous sexual phase in which multiplication occurs in several species of Anopheles mosquitoes, and an endogenous asexual phase in the vertebrate host. The time span required for mature oocyst development in the salivary glands is quite variable (7-30 days), characteristic of each species and influenced by ambient temperature. The vector Anopheles includes 465 formally recognised species. Approximately 70 of these species have the capacity to transmit Plasmodium spp. to humans and 41 are considered as dominant vector capable of transmitting malaria. The intensity of transmission is dependent on the vectorial capacity and competence of local mosquitoes. An efficient system for malaria transmission needs strong interaction between humans, the ecosystem and infected vectors. Global warming induced by human activities has increased the risk of vector-borne diseases such as malaria. Recent decades have witnessed changes in the ecosystem and climate without precedent in human history although the emphasis in the role of temperature on the epidemiology of malaria has given way to predisposing conditions such as ecosystem changes, political

  5. Relationship of Remote Sensing Normalized Differential Vegetation Index to Anopheles Density and Malaria Incidence Rate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the relationship of remote sensing normalized differential vegetation index (NDVI) to Anopheles density and malaria incidence rate. Methods Data of monthly average climate, environment, Anopheles density and malaria incidence rate, and remote sensing NDVI were collected from 27 townships of 10 counties in southeastern Yunnan Province from 1984 to 1993. The relationship of remote sensing ecological proxy index, NDVI, to Anopheles density and malaria incidence rate was studied by principal component analysis, factor analysis and grey correlation analysis. Results The correlation matrix showed that NDVI highly correlated with Anopheles density in 4 townships of Mengla, Jinghong, and Yuanjiang counties, but in other 23 townships the relationship was not clear. Principal component and factor analyses showed that remote sensing NDVI was the representative index of the first principal component and the first common factor of Anopheles density evaluation. Grey correlation analysis showed that in rainy season NDVI had a high grey correlation with Anopheles density and malaria incidence rate. The grey correlation analysis showed that in rainy season the grey degree of NDVI correlated with Anopheles. Minimus density was 0.730, and 0.713 with Anopheles sinensis density, and 0.800 with malarial incidence rate. Conclusion Remote sensing NDVI can serve as a sensitive evaluation index of Anopheles density and malaria incidence rate.

  6. A maleness gene in the malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Krzywinska, Elzbieta; Dennison, Nathan J; Lycett, Gareth J; Krzywinski, Jaroslaw

    2016-07-01

    The molecular pathways controlling gender are highly variable and have been identified in only a few nonmammalian model species. In many insects, maleness is conferred by a Y chromosome-linked M factor of unknown nature. We have isolated and characterized a gene, Yob, for the M factor in the malaria mosquito Anopheles gambiae Yob, activated at the beginning of zygotic transcription and expressed throughout a male's life, controls male-specific splicing of the doublesex gene. Silencing embryonic Yob expression is male-lethal, whereas ectopic embryonic delivery of Yob transcripts yields male-only broods. This female-killing property may be an invaluable tool for creation of conditional male-only transgenic Anopheles strains for malaria control programs.

  7. Seasonality and Locality Affect the Diversity of Anopheles gambiae and Anopheles coluzzii Midgut Microbiota from Ghana.

    Science.gov (United States)

    Akorli, Jewelna; Gendrin, Mathilde; Pels, Nana Adjoa P; Yeboah-Manu, Dorothy; Christophides, George K; Wilson, Michael D

    2016-01-01

    Symbiotic bacteria can have important implications in the development and competence of disease vectors. In Anopheles mosquitoes, the composition of the midgut microbiota is largely influenced by the larval breeding site, but the exact factors shaping this composition are currently unknown. Here, we examined whether the proximity to urban areas and seasons have an impact on the midgut microbial community of the two major malaria vectors in Africa, An. coluzzii and An. gambiae. Larvae and pupae were collected from selected habitats in two districts of Ghana during the dry and rainy season periods. The midgut microbiota of adults that emerged from these collections was determined by 454-pyrosequencing of the 16S ribosomal DNA. We show that in both mosquito species, Shewanellaceae constituted on average of 54% and 73% of the midgut microbiota from each site in the dry and rainy season, respectively. Enterobacteriaceae was found in comparatively low abundance below 1% in 22/30 samples in the dry season, and in 25/38 samples in the rainy season. Our data indicate that seasonality and locality significantly affect both the diversity of microbiota and the relative abundance of bacterial families with a positive impact of dry season and peri-urban settings.

  8. On the conspecificity of Anopheles fluviatilis species S with Anopheles minimus species C

    Indian Academy of Sciences (India)

    O P Singh; D Chandra; N Nanda; S K Sharma; Pe Than Htun; T Adak; S K Subbarao; A P Dash

    2006-12-01

    Anopheles fluviatilis and An. minimus complexes, each comprising of at least three sibling species, are closely related and important malaria vectors in Oriental Region. Recently An. fluviatilis species S, which is a highly efficient malaria vector in India, has been made conspecific with An. minimus species C (senior synonym) on the basis of homology in 335 base pair nucleotide sequence of D3 domain of 28S ribosomal DNA (rDNA). We examined the conspecificity of these two nominal species by obtaining and analysing the DNA sequences of nuclear ribosomal loci internal transcribed spacer 2 (ITS2) and D2-D3 domain of 28S rDNA (28S-D2/D3) from those of An. fluviatilis S and An. minimus C. We found that the sequences of An. fluviatilis S are appreciably different from those of An. minimus C with pair-wise distance (Kimura-2-parametre model) of 3.6 and 0.7% for loci ITS2 and 28S-D2/D3, respectively. Pair-wise distance and phylogenetic analyses using ITS2 sequences of members of Minimus and Fluviatilis Complexes revealed that An. fluviatilis S is distantly related to An. minimus C as compared to any other members of the Fluviatilis Complex. These findings suggest that the two nominal species, An. fluviatilis S and An. minimus C, do not merit synonymy. The study also confirms that the reported species An. fluviatilis X is synonym with species S.

  9. Seasonality and Locality Affect the Diversity of Anopheles gambiae and Anopheles coluzzii Midgut Microbiota from Ghana

    Science.gov (United States)

    Gendrin, Mathilde; Pels, Nana Adjoa P.; Yeboah-Manu, Dorothy; Christophides, George K.; Wilson, Michael D.

    2016-01-01

    Symbiotic bacteria can have important implications in the development and competence of disease vectors. In Anopheles mosquitoes, the composition of the midgut microbiota is largely influenced by the larval breeding site, but the exact factors shaping this composition are currently unknown. Here, we examined whether the proximity to urban areas and seasons have an impact on the midgut microbial community of the two major malaria vectors in Africa, An. coluzzii and An. gambiae. Larvae and pupae were collected from selected habitats in two districts of Ghana during the dry and rainy season periods. The midgut microbiota of adults that emerged from these collections was determined by 454-pyrosequencing of the 16S ribosomal DNA. We show that in both mosquito species, Shewanellaceae constituted on average of 54% and 73% of the midgut microbiota from each site in the dry and rainy season, respectively. Enterobacteriaceae was found in comparatively low abundance below 1% in 22/30 samples in the dry season, and in 25/38 samples in the rainy season. Our data indicate that seasonality and locality significantly affect both the diversity of microbiota and the relative abundance of bacterial families with a positive impact of dry season and peri-urban settings. PMID:27322614

  10. Locomotor behavioral responses of Anopheles minimus and Anopheles harrisoni to alpha-cypermethrin in Thailand.

    Science.gov (United States)

    Malaithong, Naritsara; Tisgratog, Rungarun; Tainchum, Krajana; Prabaripai, Atchariya; Juntarajumnong, Waraporn; Bangs, Michael J; Chareonviriyaphap, Theeraphap

    2011-09-01

    Excito-repellency responses of 3 test populations, representing 2 sibling species within the Minimus Complex, Anopheles minimus and An. harrisoni, were characterized for contact irritant and noncontact repellent actions of chemicals during and after exposure to alpha-cypermethrin at half the recommended field (0.010 g/m2), the recommended field (0.020 g/m2), and double the recommended field concentration (0.040 g/m2), using an excito-repellency escape chamber system. Two field populations of An. minimus and An. harrisoni collected from the malaria-endemic areas in Tak and Kanchanuburi provinces in western Thailand, respectively, were tested along with a laboratory population of An. minimus maintained since 1993. Females of all 3 test populations rapidly escaped after direct contact with treated surfaces for each concentration. In general, increased escape responses in the An. minimus test populations were proportionate to increased insecticide dosages. The greatest escape response for An. harrisoni was observed at the operational field concentration of alpha-cypermethrin. The noncontact repellency response to alpha-cypermethrin was comparatively weak for all 3 test populations, but significantly different from each paired contact test and respective noncontact controls. We conclude that strong contact irritancy is a major action of alpha-cypermethrin, whereas noncontact repellency plays no role in the escape responses of 2 species in the Minimus Complex in Thailand.

  11. Susceptibility Status of Anopheles sundaicus Mosquitoes Against Insecticides Cypermethrin in Garut Regency

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    Nunung Seniawati

    2010-06-01

    Full Text Available At the time of high vector populations and malaria transmission is in progress, it is necessary to use insecticides to control vector using the house spraying. To get the results as objective the eradication of the vector that is able to suppress the vector population so that no longer play a role in malaria transmission, the insecticide used should be effective against mosquitoes and the mosquitoes are still susceptible to the insecticide used. To determine the level of malaria vector mosquito susceptibility to insecticides, in the terri-tory of Garut district has conducted susceptibility tests of Anopheles sundaicus mosquitoes to insecticides Cypermethrin held in November up to December 2008. Mosquitoes tested were captured in the form of larvae from ponds and estuaries in Karyamukti Cibalong Garut, and then reared in the field insektarium. The adult level were then tested for their susceptibility. Mosquito susceptibility tests conducted using the WHO Susceptibility Test Kit as many as four repetitions performed simultaneously, while the insecticide used in the form of imprag-nated paper with a dose of 0.05%. From tests it is known that mosquito mortality rate up to 100% test. This indicates that the mosquito An. sundaicus in Garut regency of West Java, is still susceptible to the insecticide Cypermenthrin. Therefore, it can still be used in the eradication of malaria vectors in the recommended dosage of 0.20 g/m2.

  12. Biting Indices, Host-seeking Activity and Natural Infection Rates of Anopheline Species in Boa Vista, Roraima, Brazil from 1996 to 1998

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    Silva-Vasconcelos Adenildo da

    2002-01-01

    Full Text Available The epidemiology of the transmission of malaria parasites varies ecologically. To observe some entomological aspects of the malaria transmission in an urban environment, a longitudinal survey of anopheline fauna was performed in Boa Vista, Roraima, Brazil. A total of 7,263 anophelines was collected in human bait at 13 de Setembro and Caranã districts: Anopheles albitarsis sensu lato (82.8%, An. darlingi (10.3%, An. braziliensis (5.5%, An. peryassui (0.9% and An. nuneztovari (0.5%. Nightly 12 h collections showed that An. albitarsis was actively biting throughout the night with peak activities at sunset and at midnight. An. darlingi bit during all night and did not demonstrate a defined biting peak. Highest biting indices, entomological inoculation rates and malaria cases were observed seasonally during the rainy season (April-November. Hourly collections showed host seek activity for all mosquitoes peaked during the first hour after sunset. An. darlingi showed the highest plasmodial malaria infection rate followed by An. albitarsis, An. braziliensis and An. nuneztovari (8.5%, 4.6%, 3% and 2.6%, respectively. An. albitarsis was the most frequently collected anopheline, presented the highest biting index and it was the second most frequently collected infected species infected with malaria parasites. An. albitarsis and An. darlingi respectively, are the primary vectors of malaria throughout Boa Vista.

  13. Plasmodium activates the innate immune response of Anopheles gambiae mosquitoes.

    OpenAIRE

    Richman, A M; Dimopoulos, G; Seeley, D; Kafatos, F C

    1997-01-01

    Innate immune-related gene expression in the major disease vector mosquito Anopheles gambiae has been analyzed following infection by the malaria parasite, Plasmodium berghei. Substantially increased levels of mRNAs encoding the antibacterial peptide defensin and a putative Gram-negative bacteria-binding protein (GNBP) are observed 20-30 h after ingestion of an infected blood-meal, at a time which indicates that this induction is a response to parasite invasion of the midgut epithelium. The i...

  14. Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya

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    Mwangangi Joseph M

    2010-08-01

    Full Text Available Abstract Background The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru, unplanned rice cultivation (Kiamachiri and non-irrigated (Murinduko agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. Results Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252, respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval

  15. Salivary Gland Proteome during Adult Development and after Blood Feeding of Female Anopheles dissidens Mosquitoes (Diptera: Culicidae)

    Science.gov (United States)

    Phattanawiboon, Benjarat; Jariyapan, Narissara; Mano, Chonlada; Roytrakul, Sittiruk; Paemanee, Atchara; Sor-Suwan, Sriwatapron; Sriwichai, Patchara; Saeung, Atiporn; Bates, Paul A.

    2016-01-01

    Understanding changes in mosquito salivary proteins during the time that sporozoite maturation occurs and after blood feeding may give information regarding the roles of salivary proteins during the malarial transmission. Anopheles dissidens (formerly Anopheles barbirostris species A1) is a potential vector of Plasmodium vivax in Thailand. In this study, analyses of the proteomic profiles of female An. dissidens salivary glands during adult development and after blood feeding were carried out using two-dimensional gel electrophoresis coupled with nano-liquid chromatography-mass spectrometry. Results showed at least 17 major salivary gland proteins present from day one to day 21 post emergence at 8 different time points sampled. Although there was variation observed, the patterns of protein expression could be placed into one of four groups. Fifteen protein spots showed significant depletion after blood feeding with the percentages of the amount of depletion ranging from 8.5% to 68.11%. The overall results identified various proteins, including a putative mucin-like protein, an anti-platelet protein, a long form D7 salivary protein, a putative gVAG protein precursor, a D7-related 3.2 protein, gSG7 salivary proteins, and a gSG6 protein. These results allow better understanding of the changes of the salivary proteins during the adult mosquito development. They also provide candidate proteins to investigate any possible link or not between sporozoite maturation, or survival of skin stage sporozoites, and salivary proteins. PMID:27669021

  16. Genotyping of chloroquine resistant Plasmodium falciparum in wild caught Anopheles minimus mosquitoes in a malaria endemic area of Assam, India.

    Science.gov (United States)

    Sarma, D K; Mohapatra, P K; Bhattacharyya, D R; Mahanta, J; Prakash, A

    2014-09-01

    We validated the feasibility of using Plasmodium falciparum, the human malaria parasite, DNA present in wild caught vector mosquitoes for the characterization of chloroquine resistance status. House frequenting mosquitoes belonging to Anopheles minimus complex were collected from human dwellings in a malaria endemic area of Assam, Northeast India and DNA was extracted from the head-thorax region of individual mosquitoes. Anopheles minimus complex mosquitoes were identified to species level and screened for the presence of Plasmodium sp. using molecular tools. Nested PCR-RFLP method was used for genotyping of P. falciparum based on K76T mutation in the chloroquine resistance transporter (pfcrt) gene. Three of the 27 wild caught An. minimus mosquitoes were harbouring P. falciparum sporozoites (positivity 11.1%) and all 3 were had 76T mutation in the pfcrt gene, indicating chloroquine resistance. The approach of characterizing antimalarial resistance of malaria parasite in vector mosquitoes can potentially be used as a surveillance tool for monitoring transmission of antimalarial drug resistant parasite strains in the community.

  17. Mosquito biosurveillance on Kyushu Island, Japan, with emphasis on Anopheles Hyrcanus Group and related species (Diptera: culicidae).

    Science.gov (United States)

    Rueda, Leopoldo M; Pagac, Benedict; Iwakami, Masashiro; Spring, Alexandra R; Motoki, Mayasa T; Pecor, James E; Higa, Yukiko; Futami, Kyoko; Imanishi, Nozomi; Long, Lewis S; Debboun, Mustapha

    2014-01-01

    This report includes the distribution records of the Anopheles (Anopheles) Hyrcanus Group and associated species in Kyushu Island, Japan, based on our field collections from various localities of 4 prefectures (Fukuoka, Kumamoto, Nagasaki, Saga), primarily from 2002-2013. The status of common and potential mosquito vectors, particularly Anopheles species, in Japan are noted.

  18. El niño, oscilación del sur (ENOS, con relación a la transmisión de malaria, densidad y paridad de An. albimanus y An. darlingi (diptera: culicidae en dos regiones de Colombia

    Directory of Open Access Journals (Sweden)

    Ricardo Mantilla

    2000-02-01

    Full Text Available

    Una fuerte asociación ha sido registrada entre los incrementos en la transmisiónas forzadas por el fenómeno El Niño. Entre las posibles explicaciones para esta asociación está el efecto del clima sobre la dinámica de población de vectores, por ejemplo, generando cambios en la densidad y en las tasas de sobrevivencia de la población, y en la cantidad y calidad de sitios de reproducción, como también a través de cambios en el período de incubación extrínseco del parásito dentro del vector. Con el propósito de evaluar la influencia de ENOS sobre la densidad y paridad de Anopheles albimanus y An. darlingi, y su relación con la transmisión de malaria, se realizó un estudio longitudinal en Chocó y Casanare. En cada área se seleccionaron dos localidades y se realizaron muestreos entomológicos durante una semana cada mes, desde finales de 1997 hasta 1999. Este período cubrió los eventos El Niño 1997 -1998 y La Niña 1998 - 2000. En las localidades de Chocó se observó un importante incremento en el número de casos de malaria durante el evento ENOS, asociado con la temperatura. No se observó una asociación estadísticamente significativa entre los casos de malaria y la precipitación o la humedad relativa. La relación entre el incremento de malaria durante El Niño y las variables entomológicas no fue evidente. La densidad y paridad de ambas especies de vectores fluctuaron durante el período de estudio y no se encontró una asociación significativa entre estas variables y los factores climáticos como la temperatura. La precipitación y la humedad relativa. La densidad de larvas de An. albimanus fluctuó durante el estudio, y mostró altas densidades alrededor de julio - agosto. No se observó asociación entre la densidad de larvas con la densidad de adultos o las variables climáticas. El efecto del evento ENOS sobre las poblaciones de vectores

  19. Identification of one capa and two pyrokinin receptors from the malaria mosquito Anopheles gambiae

    DEFF Research Database (Denmark)

    Olsen, Stine S; Cazzamali, Giuseppe; Williamson, Michael

    2007-01-01

    We cloned the cDNA of three evolutionarily related G protein-coupled receptors from the malaria mosquito Anopheles gambiae and functionally expressed them in Chinese hamster ovary cells. One receptor, Ang-Capa-R, was only activated by the two Anopheles capa neuropeptides Ang-capa-1 (GPTVGLFAFPRVa...

  20. KARAKTERISTIK TEMPAT PERKEMBANGBIAKAN LARVA ANOPHELES DI DESA BULUBETE KECAMATAN DOLO SELATAN KABUPATEN SIGI PROVINSISULAWESI TENGAH

    OpenAIRE

    Bustam; Ruslan; Erniwati

    2008-01-01

    Malaria merupakan penyakit infeksi yang disebabkan oleh plasmodium yang ditularkan melalui gigitan nyamuk Anopheles, merupakan suatu penyakit yang mengancam umat manusia terutama yang tinggal di daerah tropik dan sub tropic. Penelitian ini bertujuan untuk mengetahui gambaran tentang kepadatan jentik vektor Malaria berdasarkan Karakteristik tempat perkembangbiakan nyamuk Anopheles di Desa Bulubete Kecamatan Dolo Selatan Kabupaten Sigi Provinsi Sulawesi Tengah. Jenis penelitian yang digunakan...

  1. Tingkat Kepadatan Larva Anopheles spp. di Delta Lakkang Kecamatan Tallo Makassar

    OpenAIRE

    Mardilah

    2016-01-01

    Telah dilakukan penelitian tentang tingkat kepadatan larva Anopheles spp di Delta Lakkang Kecamatan Tallo. Penelitian bertujuan untuk mengetahui tingkat kepadatan larva dan faktor-faktor yang mempengaruhi. Metode yang digunakan adalah metode observasi dengan mengambil larva nyamuk selanjutnya dipelihara kemudian dilakukan perhitungan tingkat kepadatan larva. Hasil penelitian menunjukkan bahwa tingkat kepadatan larva Anopheles tertinggi ditemukan di bagian barat dengan jumlah larva 179 larva p...

  2. Diversification of the Genus Anopheles and a Neotropical Clade from the Late Cretaceous.

    Directory of Open Access Journals (Sweden)

    Lucas A Freitas

    Full Text Available The Anopheles genus is a member of the Culicidae family and consists of approximately 460 recognized species. The genus is composed of 7 subgenera with diverse geographical distributions. Despite its huge medical importance, a consensus has not been reached on the phylogenetic relationships among Anopheles subgenera. We assembled a comprehensive dataset comprising the COI, COII and 5.8S rRNA genes and used maximum likelihood and Bayesian inference to estimate the phylogeny and divergence times of six out of the seven Anopheles subgenera. Our analysis reveals a monophyletic group composed of the three exclusively Neotropical subgenera, Stethomyia, Kerteszia and Nyssorhynchus, which began to diversify in the Late Cretaceous, at approximately 90 Ma. The inferred age of the last common ancestor of the Anopheles genus was ca. 110 Ma. The monophyly of all Anopheles subgenera was supported, although we failed to recover a significant level of statistical support for the monophyly of the Anopheles genus. The ages of the last common ancestors of the Neotropical clade and the Anopheles and Cellia subgenera were inferred to be at the Late Cretaceous (ca. 90 Ma. Our analysis failed to statistically support the monophyly of the Anopheles genus because of an unresolved polytomy between Bironella and A. squamifemur.

  3. Malaria entomological inoculation rates in gold mining areas of Southern Venezuela.

    Science.gov (United States)

    Moreno, Jorge E; Rubio-Palis, Yasmín; Páez, Elisa; Pérez, Enrique; Sánchez, Víctor; Vaccari, Elena

    2009-08-01

    A longitudinal study of malaria vectors aiming to describe the intensity of transmission was carried out in five villages of Southern Venezuela between January 1999-April 2000. The man-biting, sporozoite and entomological inoculation rates (EIR) were calculated based on 121 all-night collections of anophelines landing on humans, CDC light traps and ultra violet up-draft traps. A total of 6,027 female mosquitoes representing seven species were collected. The most abundant species were Anopheles marajoara Galvão & Damasceno (56.7%) and Anopheles darlingi Root (33%), which together accounted for 89.7% of the total anophelines collected. The mean biting rate for An. marajoara was 1.27 (SD + 0.81); it was 0.74 (SD + 0.91) for An. darlingi and 0.11 (SD + 0.10) for Anopheles neomaculipalpus Curry and the overall biting rate was 2.29 (SD + 1.06). A total of 5,886 mosquitoes collected by all three methods were assayed by ELISA and 28 pools, equivalent to 28 mosquitoes, yielded positive results for Plasmodium spp. CS protein. An. neomaculipalpus had the highest sporozoite rate 0.84% (3/356), followed by An. darlingi 0.82% (16/1,948) and An. marajoara 0.27% (9/3,332). The overall sporozoite rate was 0.48% (28/5,886). The rates of infection by Plasmodium species in mosquitoes were 0.37% (22/5,886) for Plasmodium vivax(Grassi & Feletti) and 0.10% (6/5,886) for Plasmodium falciparum (Welch). The estimated overall EIR for An. darlingi was 2.21 infective bites/person/year, 1.25 for An. marajoara and 0.34 for An. neomaculipalpus. The overall EIR was four infective bites/person/year. The biting rate, the sporozoite rate and the EIR are too low to be indicators of the efficacy of control campaigns in this area.

  4. Discovery of flavivirus-derived endogenous viral elements in Anopheles mosquito genomes supports the existence of Anopheles-associated insect-specific flaviviruses.

    Science.gov (United States)

    Lequime, Sebastian; Lambrechts, Louis

    2017-01-01

    The Flavivirus genus encompasses several arboviruses of public health significance such as dengue, yellow fever, and Zika viruses. It also includes insect-specific flaviviruses (ISFs) that are only capable of infecting insect hosts. The vast majority of mosquito-infecting flaviviruses have been associated with mosquito species of the Aedes and Culex genera in the Culicinae subfamily, which also includes most arbovirus vectors. Mosquitoes of the Anophelinae subfamily are not considered significant arbovirus vectors; however, flaviviruses have occasionally been detected in field-caught Anopheles specimens. Whether such observations reflect occasional spillover or laboratory contamination or whether Anopheles mosquitoes are natural hosts of flaviviruses is unknown. Here, we provide in silico and in vivo evidence of transcriptionally active, flavivirus-derived endogenous viral elements (EVEs) in the genome of Anopheles minimus and Anopheles sinensis. Such non-retroviral endogenization of RNA viruses is consistent with a shared evolutionary history between flaviviruses and Anopheles mosquitoes. Phylogenetic analyses of the two newly described EVEs support the existence of a distinct clade of Anopheles-associated ISFs.

  5. The Genetic Basis of Host Preference and Resting Behavior in the Major African Malaria Vector, Anopheles arabiensis

    Science.gov (United States)

    Main, Bradley J; Lee, Yoosook; Ferguson, Heather M.; Kreppel, Katharina S.; Kihonda, Anicet; Govella, Nicodem J.; Collier, Travis C.; Cornel, Anthony J.; Eskin, Eleazar; Kang, Eun Yong; Nieman, Catelyn C.; Weakley, Allison M.; Lanzaro, Gregory C.

    2016-01-01

    Malaria transmission is dependent on the propensity of Anopheles mosquitoes to bite humans (anthropophily) instead of other dead end hosts. Recent increases in the usage of Long Lasting Insecticide Treated Nets (LLINs) in Africa have been associated with reductions in highly anthropophilic and endophilic vectors such as Anopheles gambiae s.s., leaving species with a broader host range, such as Anopheles arabiensis, as the most prominent remaining source of transmission in many settings. An. arabiensis appears to be more of a generalist in terms of its host choice and resting behavior, which may be due to phenotypic plasticity and/or segregating allelic variation. To investigate the genetic basis of host choice and resting behavior in An. arabiensis we sequenced the genomes of 23 human-fed and 25 cattle-fed mosquitoes collected both in-doors and out-doors in the Kilombero Valley, Tanzania. We identified a total of 4,820,851 SNPs, which were used to conduct the first genome-wide estimates of “SNP heritability” for host choice and resting behavior in this species. A genetic component was detected for host choice (human vs cow fed; permuted P = 0.002), but there was no evidence of a genetic component for resting behavior (indoors versus outside; permuted P = 0.465). A principal component analysis (PCA) segregated individuals based on genomic variation into three groups which were characterized by differences at the 2Rb and/or 3Ra paracentromeric chromosome inversions. There was a non-random distribution of cattle-fed mosquitoes between the PCA clusters, suggesting that alleles linked to the 2Rb and/or 3Ra inversions may influence host choice. Using a novel inversion genotyping assay, we detected a significant enrichment of the standard arrangement (non-inverted) of 3Ra among cattle-fed mosquitoes (N = 129) versus all non-cattle-fed individuals (N = 234; χ2, p = 0.007). Thus, tracking the frequency of the 3Ra in An. arabiensis populations may be of use to infer

  6. Environmental factors associated with spatial and temporal distribution of Anopheles (Diptera: Culicidae) larvae in Sukabumi, West Java, Indonesia.

    Science.gov (United States)

    Stoops, Craig A; Gionar, Yoyo R; Shinta; Sismadi, Priyanto; Elyazar, Iqbal R F; Bangs, Michael J; Sukowati, Supratman

    2007-07-01

    A 12-mo ecological study of the spatial-temporal distribution of immature stages of Anopheles species was conducted in Sukabumi District, West Java, Indonesia. The study characterized 1,600 sites from a contiguous coastal and hill zone (0-800-m elevation) of which 64% contained Anopheles larvae. Principal component and multiple logistic regression analyses identified ecological parameters associated with presence of nine [Anopheles aconitus Doenitz, Anopheles annularis Van de Wulp, Anopheles barbirostris Van der Wulp, Anopheles flavirostris (Ludlow), Anopheles insulaeflorum (Swellengrebel and Swellengrebel de Graaf), Anopheles kochi Doenitz, Anopheles maculatus Theobald, Anopheles sundaicus (Rodenwaldt), and Anopheles vagus Doenitz] of 15 Anopheles species collected. Combined data for all nine species showed increased Anopheles presence associated with wet season periods and higher elevation habitats exhibiting reduced tree canopy coverage, higher water temperatures, and shallower water depths. Habitat variables measured included topography (elevation), water conditions (temperature, pH, salinity depth, and velocity), habitat characteristics (substrate and canopy cover), density and type of aquatic vegetation coverage (riparian, floating, and emergent), and distance from nearest human habitation. Significant relationships were found for nine species when using all habitats in the analysis. Habitat characteristics for three species were refined. An. aconitus and An. barbirostris were associated with higher elevation rice, Oryza savita L., paddies with relatively shallow water depths, higher water temperatures, higher acidity and salinity concentrations, and a greater average distance from human habitation. An. vagus presence in rice paddies was associated with lower elevation fields, deeper and cooler water, less acidic and saline conditions, and habitats closer to human dwellings. Overall, the distribution of Anopheles species in Sukabumi was found to be nonrandom

  7. Genetic Structure of Anopheles (Nyssorhynchus) marajoara (Diptera: Culicidae) in Colombia

    Science.gov (United States)

    2010-01-01

    simultaneously for all the populations studied and population pairs using R ST software. 30 From these heterogeneity statis- tics , theoretical gene-flow...statis- tic was used, the average values ranged from 0.042 to 0.047, depending on the procedures used. This statistic again showed a moderate divergence...S , Suárez M , Sánchez G , Quiñones M , Herrera M , 1987 . Uso de la técnica inmunoradiometrica (IRMA) en Anopheles de Colombia para la

  8. Responsiveness of Anopheles maculipennis to different imagicides during resurgent malaria

    Institute of Scientific and Technical Information of China (English)

    Vatandoost Hasasan; Zahirnia Amir Hossein

    2010-01-01

    Objective: To determine the susceptibility of main malaria vector in Astra County, borderline of Iran and Republic of Azerbaijan for better control. Methods:Susceptibility of Anopheles maculipennis to diagnostic doses of DDT 4%, dieldrin 0.4%, malathion 5%, lambdacyhalothrin 0.1%, and delamethrin 0.025%, was tested according to method recommended by WHO. All the impregnated papers were provided by WHO. Results: It was shown that this species exhibited resistance to DDT, dieldrin, whereas susceptible to malathrion, lambdacyhalothrin and deltamethrin. Conclusions:Findings of susceptibility tests of this species provided a clue for control of malaria vector in the region.

  9. Population genetic structure of Anopheles arabiensis (Diptera: Culicidae) in a rice growing area of central Kenya.

    Science.gov (United States)

    Muturi, Ephantus J; Kim, Chang-Hyun; Baliraine, Frederick N; Musani, Solomon; Jacob, Benjamin; Githure, John; Novak, Robert J

    2010-03-01

    Studies were conducted to examine the population genetic structure of Anopheles arabiensis (Patton) in Mwea Rice Irrigation Scheme and surrounding areas in Central Kenya, under different agricultural systems. This study was motivated by observed differences in malaria transmission indices of An. arabiensis within the scheme compared with adjacent nonirrigated areas. Agricultural practices can modify local microclimate and influence the number and diversity of larval habitats and in so doing may occasion subpopulation differentiation. Thirty samples from each of the three study sites were genotyped at eight microsatellite loci. Seven microsatellite loci showed high polymorphism but revealed no genetic differentiation (FST = 0.006, P = 0.312) and high gene flow (Nm = 29-101) among the three populations. Genetic bottleneck analysis showed no indication of excess heterozygosity in any of the populations. There was high frequency of rare alleles, suggesting that An. arabiensis in the study area has a high potential of responding to selective pressures from environmental changes and vector control efforts. These findings imply that An. arabiensis in the study area occurs as a single, continuous panmictic population with great ability to adapt to human-imposed selective pressures.

  10. High genetic differentiation between the M and S molecular forms of Anopheles gambiae in Africa.

    Directory of Open Access Journals (Sweden)

    Caroline Esnault

    Full Text Available BACKGROUND: Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status. METHODOLOGY/PRINCIPAL FINDINGS: Insertion patterns of three transposable elements (TEs were determined in populations from Benin, Burkina Faso, Cameroon, Ghana, Ivory Coast, Madagascar, Mali, Mozambique, Niger, and Tanzania, using Transposon Display, a TE-anchored strategy based on Amplified Fragment Length Polymorphism. The results reveal a clear differentiation between the M and S forms, whatever their geographical origin, suggesting an incipient speciation process. CONCLUSIONS/SIGNIFICANCE: Any attempt to control the transmission of malaria by An. gambiae using either conventional or novel technologies must take the M/S genetic differentiation into account. In addition, we localized three TE insertion sites that were present either in every individual or at a high frequency in the M molecular form. These sites were found to be located outside the chromosomal regions that are suspected of involvement in the speciation event between the two forms. This suggests that these chromosomal regions are either larger than previously thought, or there are additional differentiated genomic regions interspersed with undifferentiated regions.

  11. High Genetic Differentiation between the M and S Molecular Forms of Anopheles gambiae in Africa

    Science.gov (United States)

    Esnault, Caroline; Boulesteix, Matthieu; Duchemin, Jean Bernard; Koffi, Alphonsine A.; Chandre, Fabrice; Dabiré, Roch; Robert, Vincent; Simard, Frédéric; Tripet, Frédéric; Donnelly, Martin J.; Fontenille, Didier; Biémont, Christian

    2008-01-01

    Background Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status. Methodology/Principal Findings Insertion patterns of three transposable elements (TEs) were determined in populations from Benin, Burkina Faso, Cameroon, Ghana, Ivory Coast, Madagascar, Mali, Mozambique, Niger, and Tanzania, using Transposon Display, a TE-anchored strategy based on Amplified Fragment Length Polymorphism. The results reveal a clear differentiation between the M and S forms, whatever their geographical origin, suggesting an incipient speciation process. Conclusions/Significance Any attempt to control the transmission of malaria by An. gambiae using either conventional or novel technologies must take the M/S genetic differentiation into account. In addition, we localized three TE insertion sites that were present either in every individual or at a high frequency in the M molecular form. These sites were found to be located outside the chromosomal regions that are suspected of involvement in the speciation event between the two forms. This suggests that these chromosomal regions are either larger than previously thought, or there are additional differentiated genomic regions interspersed with undifferentiated regions. PMID:18414665

  12. Low linkage disequilibrium in wild Anopheles gambiae s.l. populations

    Directory of Open Access Journals (Sweden)

    Harris Caroline

    2010-09-01

    Full Text Available Abstract Background In the malaria vector Anopheles gambiae, understanding diversity in natural populations and genetic components of important phenotypes such as resistance to malaria infection is crucial for developing new malaria transmission blocking strategies. The design and interpretation of many studies here depends critically on Linkage disequilibrium (LD. For example in association studies, LD determines the density of Single Nucleotide Polymorphisms (SNPs to be genotyped to represent the majority of the genomic information. Here, we aim to determine LD in wild An. gambiae s.l. populations in 4 genes potentially involved in mosquito immune responses against pathogens (Gambicin, NOS, REL2 and FBN9 using previously published and newly generated sequences. Results The level of LD between SNP pairs in cloned sequences of each gene was determined for 7 species (or incipient species of the An. gambiae complex. In all tested genes and species, LD between SNPs was low: even at short distances (2 2 ranged from 0.073 to 0.766. In most genes and species LD decayed very rapidly with increasing inter-marker distance. Conclusions These results are of great interest for the development of large scale polymorphism studies, as LD generally falls below any useful limit. It indicates that very fine scale SNP detection will be required to give an overall view of genome-wide polymorphism. Perhaps a more feasible approach to genome wide association studies is to use targeted approaches using candidate gene selection to detect association to phenotypes of interest.

  13. Identifying Anophele fauna in Qayenat city in the South khorasan Province (2010-2011

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    Hossien Borna

    2013-08-01

    Full Text Available Background and Aim: Biological vectors of malaria are only anopheles mosquitoes. Since the vector control without identifying them and understanding their biology is not possible, the present study was designed to identify anopheles fauna in different areas of Qayenat city and their internal or external shelters.   Materials and Methods: Larvae, pupae, and adults of anopheles mosquitoes were collected from their internal and external shelters in rural areas in plains and mountainous spots in Qayenat city during a cross-sectional and descriptive study between April 2010 and October 2011. This was done either singularly or collectively through taking samples of the larvae from various inhabitats through scooping. The caught samples were transferred to laboratory in order to determine their type using the valid key to identify adult anopheles and larvae in Iran (Shahgvdyan.   Results: A total of 2165 samples including 1711 larvae and 454 adults were collected from different parts of Qayenat city. After identification and validation of the samples 4 species of Anopheles were diagnosed. The samples were superpictus, multicolor, sacharovi, and turkhodai with the percent 72.2%, 27.9%, 0.44%, and 0.44% respectively. Most abundant Anopheles were reported to exist in the months of July and August.   Conclusion: Regarding the high frequency of superpictus anopheles in the area and its condition, it is necessary to make essential provision for a comprehensive program to control malaria In order to prevent outbreaks of the epidemic in suitable seasons of the year.

  14. Identification of field caught Anopheles gambiae s.s. and Anopheles arabiensis by TaqMan single nucleotide polymorphism genotyping

    Directory of Open Access Journals (Sweden)

    Bayoh Nabie M

    2007-02-01

    Full Text Available Abstract Background Identification of Anopheles gambiae s.s. and Anopheles arabiensis from field-collected Anopheles gambiae s.l. is often necessary in basic and applied research, and in operational control programmes. The currently accepted method involves use of standard polymerase chain reaction amplification of ribosomal DNA (rDNA from the 3' 28S to 5' intergenic spacer region of the genome, and visual confirmation of amplicons of predicted size on agarose gels, after electrophoresis. This report describes development and evaluation of an automated, quantitative PCR method based upon TaqMan™ single nucleotide polymorphism (SNP genotyping. Methods Standard PCR, and TaqMan SNP genotyping with newly designed primers and fluorophore-labeled probes hybridizing to sequences of complementary rDNA specific for either An. gambiae s.s. or An. arabiensis, were conducted in three experiments involving field-collected An. gambiae s.l. from western Kenya, and defined laboratory strains. DNA extraction was from a single leg, sonicated for five minutes in buffer in wells of 96-well PCR plates. Results TaqMan SNP genotyping showed a reaction success rate, sensitivity, and species specificity comparable to that of standard PCR. In an extensive field study, only 29 of 3,041 (0.95% were determined to be hybrids by TaqMan (i.e., having rDNA sequences from both species, however, all but one were An. arabiensis by standard PCR, suggesting an acceptably low (ca. 1% error rate for TaqMan genotyping in mistakenly identifying species hybrids. Conclusion TaqMan SNP genotyping proved to be a sensitive and rapid method for identification of An. gambiae s.l. and An. arabiensis, with a high success rate, specific results, and congruence with the standard PCR method.

  15. Three years of insecticide resistance monitoring in Anopheles gambiae in Burkina Faso: resistance on the rise?

    Directory of Open Access Journals (Sweden)

    Badolo Athanase

    2012-07-01

    Full Text Available Abstract Background and methods A longitudinal Anopheles gambiae s.l. insecticide-resistance monitoring programme was established in four sentinel sites in Burkina Faso. For three years, between 2008 and 2010, WHO diagnostic dose assays were used to measure the prevalence of resistance to all the major classes of insecticides at the beginning and end of the malaria transmission season. Species identification and genotyping for target site mutations was also performed and the sporozoite rate in adults determined. Results At the onset of the study, resistance to DDT and pyrethroids was already prevalent in An. gambiae s.l. from the south-west of the country but mosquitoes from the two sites in central Burkina Faso were largely susceptible. Within three years, DDT and permethrin resistance was established in all four sites. Carbamate and organophosphate resistance remains relatively rare and largely confined to the south-western areas although a small number of bendiocarb survivors were found in all sites by the final round of monitoring. The ace-1R target site resistance allele was present in all localities and its frequency exceeded 20% in 2010 in two of the sites. The frequency of the 1014F kdr mutation increased throughout the three years and by 2010, the frequency of 1014F in all sites combined was 0.02 in Anopheles arabiensis, 0.56 in An. gambiae M form and 0.96 in An. gambiae S form. This frequency did not differ significantly between the sites. The 1014S kdr allele was only found in An. arabiensis but its frequency increased significantly throughout the study (P = 0.0003 and in 2010 the 1014S allele frequency was 0.08 in An. arabiensis. Maximum sporozoite rates (12% were observed in Soumousso in 2009 and the difference between sites is significant for each year. Conclusion Pyrethroid and DDT resistance is now established in An. gambiae s.l. throughout Burkina Faso. Results from diagnostic dose assays are highly variable within and

  16. Bioinformatics-Based Identification of Chemosensory Proteins in African Malaria Mosquito, Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Zhengxi Li; Zuorui Shen; Jingjiang Zhou; Lin Field

    2003-01-01

    Chemosensory proteins (CSPs) are identifiable by four spatially conserved Cysteine residues in their primary structure or by two disulfide bridges in their tertiary structure according to the previously identified olfactory specific-D related proteins. A genomics- and bioinformatics-based approach is taken in the present study to identify the putative CSPs in the malaria-carrying mosquito, Anopheles gambiae. The results show that five out of the nine annotated candidates are the most possible Anopheles CSPs of A. gambiae. This study lays the foundation for further functional identification of Anopheles CSPs, though all of these candidates need additional experimental verification.

  17. Manutenção em laboratório de Anopheles albitarsis e Anopheles aquasalis por copulacao induzida Laboratory maintence of Anopheles albitarsis and Anopheles aquasalis by induced copulation

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    Mercia E. Arruda

    1982-03-01

    Full Text Available Introduzimos a técnica da copulação induzida para a manutenção e criação em cativeiro, do Anopheles albitarsis e do A. aquasalis, objetivando facilitar futuros trabalhoscom estas espécies de difícil cruzamento espontâneo em laboratório.Many species of mosquitoes are unsuited to life in a laboratory because they fail to copulate in cages. This situation may be largely eliminated by the technique in current use for manually inducing inseminations as outlined. We have used this technique for the first time in relation to Anopheles albitarsis and A. aquasalis, species of malaria vectors which are difficult to mate spontaneously in captivity. The pre-mating age of the males and the temperature at which they are held affect the ability of male to transfer sperm. Mating males 8 to 14 days old with females at any age, resulted in a high order of insemination. Temperature of 25°C and humidity of 80% RH enhanced the degree of insemination.

  18. Differentially expressed genes between female and male adult Anopheles anthropophagus.

    Science.gov (United States)

    Geng, Yi-Jie; Gao, Shi-Tong; Huang, Da-Na; Zhao, Yi-Rui; Liu, Jian-ping; Li, Xiao-Heng; Zhang, Ren-Li

    2009-09-01

    The aim of the present study was to identify sex-specific genes in adult Anopheles anthropophagus. As the major malaria vector and Brugia malayi vector in the Asian continent, female Anopheles mosquitoes take blood meals and transmit pathogens through this pathway, while males are nectar feeders. This complex behavior is controlled at several levels, but is probably initiated by the genetic background difference between these two groups. In our study, a subtractive cDNA library for female A. anthropophagus was constructed using the suppression subtractive hybridization (SSH) technique and then 3,074 clones from the female SSH library were analyzed using a microarray-based survey. Genes that were expressed differentially according to sex in A. anthropophagus were screened using real-time polymerase chain reaction and reverse transcription polymerase chain reaction. In our results, we report a series of genes which may be involved in female-specific mosquito behavior, including an inorganic phosphate transporter, a serine protease, the salivary protein GP35-2, and the D7 cluster salivary protein. These findings will provide clues to the nature of insect vectors and open up unprecedented opportunities to develop novel strategies for the control of mosquito-borne diseases.

  19. Variability and genetic differentiation among Anopheles (Ano. intermedius Chagas, 1908 and Anopheles (Ano. mattogrossensis Lutz & Neiva, 1911 (Diptera: Culicidae from the Brazilian Amazon

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    Joselita Maria Mendes dos Santos

    2005-10-01

    Full Text Available Anopheles (Anopheles intermedius and Anopheles (Ano. mattogrossensis are Brazilian anopheline species belonging to the scarcely studied Anopheles subgenus. Few studies have been done on the genetic differentiation of these species. Both species have been found infected by Plasmodium and are sympatric with other anopheline species from the Nyssorhynchus subgenus. Eighteen enzymatic loci were analyzed in larval specimens of An. intermedius and An. mattogrossensis aiming to estimate the variability and genetic differentiation between these species. An. mattogrossensis population showed higher genetic variability (P = 44.4 and Ho = 0.081 ± 0.031 than that of An. intermedius (P = 33.3 and Ho = 0.048 ± 0.021. Most analyzed loci showed genotypic frequencies according to Hardy-Weinberg equilibrium, except for LAP1 and LAP2 in An. intermedius, and EST1 and PGM loci in An. mattogrossensis. The genetic distance between these species (D = 0.683 was consistent with the inter-specific values reported for Anopheles subgenus. We verified that the polymorphism and heterozygosity percentile values found in both species and compared to those in the literature, showed no relation between the level of isozyme variability and geographical distribution. The low variability found in these two species is probably more related to the niche they occupy than to their geographic distribution.

  20. Molecular comparison of topotypic specimens confirms Anopheles (Nyssorhynchus dunhami Causey (Diptera: Culicidae in the Colombian Amazon

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    Freddy Ruiz

    2010-11-01

    Full Text Available The presence of Anopheles (Nyssorhynchus dunhami Causey in Colombia (Department of Amazonas is confirmed for the first time through direct comparison of mtDNA cytochrome c oxidase I (COI barcodes and nuclear rDNA second internal transcribed spacer (ITS2 sequences with topotypic specimens of An. dunhami from Tefé, Brazil. An. dunhami was identified through retrospective correlation of DNA sequences following misidentification as Anopheles nuneztovari s.l. using available morphological keys for Colombian mosquitoes. That An. dunhami occurs in Colombia and also possibly throughout the Amazon Basin, is of importance to vector control programs, as this non-vector species is morphologically similar to known malaria vectors including An. nuneztovari, Anopheles oswaldoi and Anopheles trinkae. Species identification of An. dunhami and differentiation from these closely related species are highly robust using either DNA ITS2 sequences or COI DNA barcode. DNA methods are advocated for future differentiation of these often sympatric taxa in South America.

  1. Mosquitoes of Anopheles hyrcanus (Diptera, Culicidae) Group: Species Diagnostic and Phylogenetic Relationships.

    Science.gov (United States)

    Khrabrova, Natalia V; Andreeva, Yulia V; Sibataev, Anuarbek K; Alekseeva, Svetlana S; Esenbekova, Perizat A

    2015-09-01

    Herein, we report the results of study of Anopheles species in Primorsk and Khabarovsk regions of Russia. Three species of the Anopheles hyrcanus group: An. kleini, An. pullus, and An. lesteri were identified by molecular taxonomic diagnostics for the first time in Russia. Surprisingly, An. sinensis, which earlier was considered the only species of Anopheles in Russian Far East, was not observed. We analyzed nucleotide variation in the 610-bp fragment of the 5' end of the cytochrome c oxidase subunit I (COI) region. All species possessed a distinctive set of COI sequences. A maximum likelihood phylogenetic tree was constructed for members of the hyrcanus group. The examined Anopheles hyrcanus group members could be divided into two major subgroups: subgroup 1 (An. hyrcanus and An. pullus) and subgroup 2 (An. sinensis, An. kleini, and An. lesteri), which were found to be monophyletic.

  2. Avoidance behavior to essential oils by Anopheles minimus, a malaria vector in Thailand

    Science.gov (United States)

    Excito-repellency tests were used to characterize behavioral responses of laboratory colonized Anopheles minimus, a malaria vector in Thailand, using four essential oils, citronella (Cymbopogom nadus), hairy basil (Ocimum americanum), sweet basil (Ocimum basilicum), vetiver (Vetiveria zizanioides), ...

  3. BEBERAPA ASPEK PERILAKU NYAMUK Anopheles barbirostris DI KABUPATEN SUMBA TENGAH TAHUN 2011

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    Monika Noshirma

    2013-02-01

    Full Text Available Abstract Some aspects of Anopheles barbirostris behavior in Central Sumba Regency was conducted in July– October in District Umbu Ratu Nggai (Village Padira Tana which represents in mountain ecology and the district of Mamboro (Manu Wollu Village representing the coastal ecology. Both villages are selected to have high malaria cases during the past year. The objective of the study is to determine Some aspect of Anopheles barbirostris behavior in Central Sumba Regency. The result showed that the characteristics of  breeding habitats of Anopheles barbirostris in the padira tana village is in fields (both in use, not use or ready for planting and in kobakan. in Manu Wolu Village the breeding habitats are in former ponds, puddles an kobakan. The bitting activity of Anopheles barbirostris the in Padira Tana Village highest in July (MBR = 0.08 outside the house,  while in Manu Wolu Village bite out of the house in July and October (MBR = 0.04. in the Padira Tana Village and Manu Wollu village the Anopheles barbirostris is most prevalent in the cage with peak hours 11.00 pm to 04.00 am. Keyword: some aspect of vector behavior, Anopheles barbirostris Abstrak Studi beberapa aspek perilaku vektor malaria Anopheles barbirostris di Kabupaten Sumba Tengah dilaksanakan pada bulan Juli – Oktober di 2 Kecamatan yaitu Kecamatan Umbu Ratu (Desa Padira Tana yang mewakili ekologi pegunungan dan Kecamatan Mamboro (Desa Manu Wolu yang mewakili ekologi pantai. Kedua desa yang dipilih mempunyai kasus malaria tinggi selama satu tahun terakhir. Tujuan penelitian ini untuk mengetahui beberapa aspek perilaku vektor Anopheles barbirostris di Kabupaten Sumba Tengah. Hasil penelitian menunjukan bahwa karakteristik habitat perkembangbiakan Anopheles barbirostris di desa Padira Tana adalah sawah (baik yang terpakai, tidak dipakai maupun siap tanam dan di kobakan. Sedangkan di desa Manu Wolu ditemukan di bekas kolam, kubangan dan kobakan.    Kepadatan nyamuk An

  4. Molecular Comparison of Topotypic Specimens Confirms Anopheles (Nyssorhynchus) dunhami Causey (Diptera: Culicidae) in the Colombian Amazon

    Science.gov (United States)

    2010-11-01

    of Health, Albany, NY, USA 5Facultad de Medicina , Universidad Nacional de Colombia, Bogotá, Colombia 6Programa de Estudio y Control de Enfermedades...Tropicales, Facultad de Medicina , Universidad de Antioquia, Medellín, Colombia The presence of Anopheles (Nyssorhynchus) dunhami Causey in Colombia...Anopheles nuneztovari C used in this study, alongside GenBank accessions for second internal transcribed spacer (ITS2) and cytochrome c oxidase I (COI

  5. Hemozoin activates the innate immune system and reduces Plasmodium berghei infection in Anopheles gambiae

    OpenAIRE

    Simões, Maria L; Gonçalves, Luzia; Silveira, Henrique

    2015-01-01

    Background Malaria is a worldwide infectious disease caused by Plasmodium parasites and transmitted by female Anopheles mosquitoes. The malaria vector mosquito Anopheles can trigger effective mechanisms to control completion of the Plasmodium lifecycle; the mosquito immune response to the parasite involves several pathways which are not yet well characterized. Plasmodium metabolite hemozoin has emerged as a potent immunostimulator of mammalian tissues. In this study, we aim to investigate the...

  6. Abundance, biting behaviour and parous rate of anopheline mosquito species in relation to malaria incidence in gold-mining areas of southern Venezuela.

    Science.gov (United States)

    Moreno, J E; Rubio-Palis, Y; Páez, E; Pérez, E; Sánchez, V

    2007-12-01

    A longitudinal entomological and epidemiological study was conducted in five localities of southern Venezuela between January 1999 and April 2000 to determine the abundance, biting behaviour and parity of anopheline mosquitoes (Diptera: Culicidae) in relation to climate variables and malaria incidence. A total of 3685 female anopheline mosquitoes, representing six species, were collected. The most abundant species were Anopheles marajoara Galvão & Damasceno (60.7%) and Anopheles darlingi Root (35.1%), which together represented 95.8% of the total anophelines collected. Abundance and species distribution varied by locality. Malaria prevalence varied from 12.5 to 21.4 cases per 1000 population. Transmission occurred throughout the year; the annual parasite index (API) for the study period was 813.0 cases per 1000 population, with a range of 71.6-2492 per 1000 population, depending on locality. Plasmodium vivax (Grassi & Feletti) (Coccidia: Plasmodiidae) accounted for 78.6% of cases, Plasmodium falciparum (Welch) for 21.4% and mixed infections (Pv+Pf) for 0.05) between mosquito abundance and rainfall. Correlations between malaria incidence by parasite species and mosquito abundance were not significant (P > 0.05). Monthly parous rates were similar for An. marajoara and An. darlingi throughout the year, with two peaks that coincided with the dry-rainy transition period and the period of less rain. Peaks in the incidence of malaria cases were observed 1 month after major peaks in biting rates of parous anophelines. Anopheles darlingi engages in biting activity throughout the night, with two minor peaks at 23.00-00.00 hours and 03.00-04.00 hours. Anopheles marajoara has a different pattern, with a biting peak at 19.00-21.00 hours and 76.6% of biting occurring before midnight. Although both vectors bite indoors and outdoors, they showed a highly significant (P Venezuela and to provide relevant information to be considered when planning and implementing vector control

  7. Salivary gland proteome analysis reveals modulation of anopheline unique proteins in insensitive acetylcholinesterase resistant Anopheles gambiae mosquitoes.

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    Sylvie Cornelie

    Full Text Available Insensitive acetylcholinesterase resistance due to a mutation in the acetylcholinesterase (ace encoding ace-1 gene confers cross-resistance to organophosphate and carbamate insecticides in Anopheles gambiae populations from Central and West Africa. This mutation is associated with a strong genetic cost revealed through alterations of some life history traits but little is known about the physiological and behavioural changes in insects bearing the ace-1(R allele. Comparative analysis of the salivary gland contents between An. gambiae susceptible and ace-1(R resistant strains was carried out to charaterize factors that could be involved in modifications of blood meal process, trophic behaviour or pathogen interaction in the insecticide-resistant mosquitoes. Differential analysis of the salivary gland protein profiles revealed differences in abundance for several proteins, two of them showing major differences between the two strains. These two proteins identified as saglin and TRIO are salivary gland-1 related proteins, a family unique to anopheline mosquitoes, one of them playing a crucial role in salivary gland invasion by Plasmodium falciparum sporozoites. Differential expression of two other proteins previously identified in the Anopheles sialome was also observed. The differentially regulated proteins are involved in pathogen invasion, blood feeding process, and protection against oxidation, relevant steps in the outcome of malaria infection. Further functional studies and insect behaviour experiments would confirm the impact of the modification of the sialome composition on blood feeding and pathogen transmission abilities of the resistant mosquitoes. The data supports the hypothesis of alterations linked to insecticide resistance in the biology of the primary vector of human malaria in Africa.

  8. Development of the bi-partite Gal4-UAS system in the African malaria mosquito, Anopheles gambiae.

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    Amy Lynd

    Full Text Available Functional genetic analysis in Anopheles gambiae would be greatly improved by the development of a binary expression system, which would allow the more rapid and flexible characterisation of genes influencing disease transmission, including those involved in insecticide resistance, parasite interaction, host and mate seeking behaviour. The Gal4-UAS system, widely used in Drosophila melanogaster functional genetics, has been significantly modified to achieve robust application in several different species. Towards this end, previous work generated a series of modified Gal4 constructs that were up to 20 fold more active than the native gene in An. gambiae cells. To examine the Gal4-UAS system in vivo, transgenic An. gambiae driver lines carrying a modified Gal4 gene under the control of the carboxypeptidase promoter, and responder lines carrying UAS regulated luciferase and eYFP reporter genes have been created. Crossing of the Gal4 and UAS lines resulted in progeny that expressed both reporters in the expected midgut specific pattern. Although there was minor variation in reporter gene activity between the different crosses examined, the tissue specific expression pattern was consistent regardless of the genomic location of the transgene cassettes. The results show that the modified Gal4-UAS system can be used to successfully activate expression of transgenes in a robust and tissue specific manner in Anopheles gambiae. The midgut driver and dual reporter responder constructs are the first to be developed and tested successfully in transgenic An. gambiae and provide the basis for further advancement of the system in this and other insect species.

  9. Comparative efficacies of permethrin-, deltamethrin- and alpha-cypermethrin-treated nets, against Anopheles arabiensis and Culex quinquefasciatus in northern Tanzania.

    Science.gov (United States)

    Mosha, F W; Lyimo, I N; Oxborough, R M; Matowo, J; Malima, R; Feston, E; Mndeme, R; Tenu, F; Kulkarni, M; Maxwell, C A; Magesa, S M; Rowland, M W

    2008-06-01

    Mosquito nets treated with permethrin, deltamethrin or alpha-cypermethrin at 25 mg/m(2) were evaluated in experimental huts in an area of rice irrigation near Moshi, in northern Tanzania. The nets were deliberately holed to resemble worn nets. The nets treated with permethrin offered the highest personal protection against Anopheles arabiensis (61.6% reduction in fed mosquitoes) and Culex quinquefasciatus (25.0%). Deltamethrin and alpha-cypermethrin provided lower personal protection against An. arabiensis (46.4% and 45.6%, respectively) and no such protection against Cx. quinquefasciatus. Permethrin performed poorly in terms of mosquito mortality, however, killing only 15.2% of the An. arabiensis and 9.2% of the Cx. quinquefasciatus exposed to the nets treated with this pyrethroid (after correcting for control mortality). The alpha-cypermethrin and deltamethrin performed marginally better, with respective mortalities of 32.8% and 33.0% for An. arabiensis and 19.4% and 18.9% for Cx quinquefasciatus. The poor killing effect of permethrin was confirmed in a second trial where a commercial, long-lasting insecticidal net based on this pyrethroid (Olyset) produced low mortalities in both An. arabiensis (11.8%) and Cx. quinquefasciatus (3.6%). Anopheles arabiensis survivors collected from the verandahs of the experimental huts and tested on 0.75%-permethrin and 0.05%-deltamethrin papers, in World Health Organization susceptibility kits, showed mortalities of 96% and 100%, respectively. The continued use of permethrin-treated nets is recommended for personal protection against An. arabiensis. In control programmes that aim to interrupt transmission of pathogens by mosquitoes and/or manage pyrethroid resistance in such vectors, a combination of a pyrethroid and another insecticide with greater killing effect should be considered.

  10. Risk mapping of Anopheles gambiae s.l. densities using remotely-sensed environmental and meteorological data in an urban area: Dakar, Senegal.

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    Vanessa Machault

    Full Text Available INTRODUCTION: High malaria transmission heterogeneity in an urban environment is basically due to the complex distribution of Anopheles larval habitats, sources of vectors. Understanding 1 the meteorological and ecological factors associated with differential larvae spatio-temporal distribution and 2 the vectors dynamic, both may lead to improving malaria control measures with remote sensing and high resolution data as key components. In this study a robust operational methodology for entomological malaria predictive risk maps in urban settings is developed. METHODS: The Tele-epidemiology approach, i.e., 1 intensive ground measurements (Anopheles larval habitats and Human Biting Rate, or HBR, 2 selection of the most appropriate satellite data (for mapping and extracting environmental and meteorological information, and 3 use of statistical models taking into account the spatio-temporal data variability has been applied in Dakar, Senegal. RESULTS: First step was to detect all water bodies in Dakar. Secondly, environmental and meteorological conditions in the vicinity of water bodies favoring the presence of Anopheles gambiae s.l. larvae were added. Then relationship between the predicted larval production and the field measured HBR was identified, in order to generate An. gambiae s.l. HBR high resolution maps (daily, 10-m pixel in space. DISCUSSION AND CONCLUSION: A robust operational methodology for dynamic entomological malaria predictive risk maps in an urban setting includes spatio-temporal variability of An. gambiae s.l. larval habitats and An. gambiae s.l. HBR. The resulting risk maps are first examples of high resolution products which can be included in an operational warning and targeting system for the implementation of vector control measures.

  11. Organization of olfactory centres in the malaria mosquito Anopheles gambiae

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    Riabinina, Olena; Task, Darya; Marr, Elizabeth; Lin, Chun-Chieh; Alford, Robert; O'Brochta, David A.; Potter, Christopher J.

    2016-01-01

    Mosquitoes are vectors for multiple infectious human diseases and use a variety of sensory cues (olfactory, temperature, humidity and visual) to locate a human host. A comprehensive understanding of the circuitry underlying sensory signalling in the mosquito brain is lacking. Here we used the Q-system of binary gene expression to develop transgenic lines of Anopheles gambiae in which olfactory receptor neurons expressing the odorant receptor co-receptor (Orco) gene are labelled with GFP. These neurons project from the antennae and maxillary palps to the antennal lobe (AL) and from the labella on the proboscis to the suboesophageal zone (SEZ), suggesting integration of olfactory and gustatory signals occurs in this brain region. We present detailed anatomical maps of olfactory innervations in the AL and the SEZ, identifying glomeruli that may respond to human body odours or carbon dioxide. Our results pave the way for anatomical and functional neurogenetic studies of sensory processing in mosquitoes. PMID:27694947

  12. Larvicidal efficacy of monoterpenes against the larvae of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Eliningaya J.Kweka; Tamires Cardoso Lima; Chrian M.Marciale; Dami?o Pergentino de Sousa

    2016-01-01

    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 LC50 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(LC50= 135.10,49.39,34.39 and 20.22 mg/L) and(-)-carvone epoxide(LC50= 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 LC50 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.

  13. Insecticide resistance status in Anopheles gambiae in southern Benin

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    Corbel Vincent

    2010-03-01

    Full Text Available Abstract Background The emergence of pyrethroid resistance in Anopheles gambiae has become a serious concern to the future success of malaria control. In Benin, the National Malaria Control Programme has recently planned to scaling up long-lasting insecticidal nets (LLINs and indoor residual spraying (IRS for malaria prevention. It is, therefore, crucial to monitor the level and type of insecticide resistance in An. gambiae, particularly in southern Benin where reduced efficacy of insecticide-treated nets (ITNs and IRS has previously been reported. Methods The protocol was based on mosquito collection during both dry and rainy seasons across forty districts selected in southern Benin. Bioassay were performed on adults collected from the field to assess the susceptibility of malaria vectors to insecticide-impregnated papers (permethrin 0.75%, delthamethrin 0.05%, DDT 4%, and bendiocarb 0.1% following WHOPES guidelines. The species within An. gambiae complex, molecular form and presence of kdr and ace-1 mutations were determined by PCR. Results Strong resistance to permethrin and DDT was found in An. gambiae populations from southern Benin, except in Aglangandan where mosquitoes were fully susceptible (mortality 100% to all insecticides tested. PCR showed the presence of two sub-species of An. gambiae, namely An. gambiae s.s, and Anopheles melas, with a predominance for An. gambiae s.s (98%. The molecular M form of An. gambiae was predominant in southern Benin (97%. The kdr mutation was detected in all districts at various frequency (1% to 95% whereas the Ace-1 mutation was found at a very low frequency (≤ 5%. Conclusion This study showed a widespread resistance to permethrin in An. gambiae populations from southern Benin, with a significant increase of kdr frequency compared to what was observed previously in Benin. The low frequency of Ace-1 recorded in all populations is encouraging for the use of bendiocarb as an alternative insecticide to

  14. Competency of Anopheles stephensi mysorensis strain for Plasmodium vivax and the role of inhibitory carbohydrates to block its sporogonic cycle

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    Whitten Miranda MA

    2008-07-01

    Full Text Available Abstract Background Despite the abundance of studies conducted on the role of mosquitoes in malaria transmission, the biology and interaction of Plasmodium with its insect host still holds many mysteries. This paper provides the first study to follow the sporogonic cycle of Plasmodium vivax in a wild insecticide-resistant mysorensis strain of Anopheles stephensi, a major vector of vivax malaria in south-eastern Iran. The study subsequently demonstrates that host-parasite sugar binding interactions are critical to the development of this parasite in the salivary glands of its mosquito host. The identity of the receptors or sugars involved was revealed by a receptor "pre-saturation" strategy in which sugars fed to the mosquitoes inhibited normal host-parasite interactions. Methods Anopheles stephensi mysorensis mosquitoes were artificially infected with P. vivax by feeding on the blood of gametocytaemic volunteers reporting to local malaria clinics in the Sistan-Baluchistan province of south-eastern Iran. In order to determine the inhibitory effect of carbohydrates on sporogonic development, vector mosquitoes were allowed to ingest blood meals containing both gametocytes and added carbohydrates. The carbohydrates tested were GlcNAc, GalNAc, arabinose, fucose, mannose, lactose, glucose and galactose. Sporogonic development was assessed by survival of the parasite at both the oocyst and sporozoite stages. Results Oocyst development was observed among nearly 6% of the fed control mosquitoes but the overall number of mosquitoes exhibiting sporozoite invasion of the salivary glands was 47.5% lower than the number supporting oocysts in their midgut. Of the tested carbohydrates, only arabinose and fucose slightly perturbed the development of P. vivax oocysts at the basal side of the mosquito midgut, and the remaining sugars caused no reductions in oocyst development. Strikingly however, sporozoites were completely absent from the salivary glands of

  15. Distribuição vertical e sazonal de Anopheles (Kerteszia em Ilha Comprida, SP Vertical and seasonal distribution of Anopheles (Kerteszia in Ilha Comprida, Southeastern Brazil

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    Helene Mariko Ueno

    2007-04-01

    Full Text Available OBJETIVO: Anopheles bellator e An. cruzii são vetores da malária-bromélia, característicos de áreas preservadas. O objetivo do estudo foi analisar a distribuição sazonal e vertical desses anofelinos, visando contribuir para a avaliação do risco de transmissão desse agravo. MÉTODOS: No município de Ilha Comprida, SP, foram instaladas armadilhas luminosas tipo CDC iscadas com gelo seco, das 17 às 20h, a um, seis e 12m do solo, quinzenalmente, de setembro de 2001 a setembro de 2002. A relação da densidade desses anofelinos com o clima foi avaliada pelo coeficiente de Spearman e suas densidades entre os estratos foram comparadas pelo teste não paramétrico de Mann-Whitney. RESULTADOS: Do total de 55.226 mosquitos, 1.341 eram An. bellator (2,4% do total de Culicidae, sendo capturados 278 indivíduos próximo ao solo, 261 a seis metros e 802 na copa (12 m. Na mesma ordem, foram capturados 452, 1.032 e 4.420 adultos de An. cruzii, totalizando 5.904 mosquitos desta espécie (10,7%. Houve correlação positiva entre a densidade das duas espécies com a temperatura máxima, e entre An. bellator e amplitude térmica diária. As densidades das duas espécies foram maiores na copa. Nos três estratos, An. cruzii predominou sobre An. bellator. CONCLUSÕES: Confirmou-se o comportamento acrodendrófilo dessas espécies, principalmente An. cruzii. Após medidas drásticas de controle, esses anofelinos permaneceram na região mas, atualmente, não são alvo de vigilância entomológica. A persistência da transmissão de malária autóctone e o incremento de atividades de ecoturismo na região apontam a necessidade de monitoramento dessas espécies.OBJECTIVE: Anopheles bellator e An. cruzii are vectors of the so-called bromeliad-malaria, typical of conserved areas. The objective was to evaluate the seasonal and vertical distribution of these anophelines, aiming at assessing the risk of malaria transmission. METHODS: In the municipality of Ilha

  16. The neotype of anopheles albitarsis (Diptera: culicidae O neótipo de Anopheles albitarsis (Diptera: Culicidae

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    Maria Goreti Rosa-Freitas

    1989-09-01

    Full Text Available Anopheles albitarsis neotype is described from specimens collected in Baradero, Argentina, in Shannon's trap, in horse and pig stables and on the progeny of engorded females. The description includes illustrations of adult female, male and female genitalias, scanning electron miscroscopy of the eggs and complete chaetotaxy of pupa and larva. The importance for electing a neotype is based on the realization that An. albitarsis is a complex of cryptic species. It is an attempt to provide typt-locality specimens with which other memebers of the group can be compared.O neótipo de Anopheles albitarsis é descrito a partir de espécimens coletados em armadilha tipo Shannon, em estábulos de cavalos e porcos e progênies de fêmeas ingurgitadas em Baradero, Argentina, localidade-tipo da espécie. A descrição inclui ilustrações da fêmea adulda, genitálias masculina e feminina, ovos em microscopia eletrônica de varredura e da quetotaxia completa das larvas de 4º estádio e pupas. A eleição de um neótipo para albitarsis baseia-se em dados recentes que apontam a espécie como um complexo de espécies crípticas, o que evidencia a importância de uma descrição detalhada de espécimens da localidade-tipo com o qual outros membros do grupo possam ser comparados.

  17. A CRISPR-Cas9 gene drive system targeting female reproduction in the malaria mosquito vector Anopheles gambiae.

    Science.gov (United States)

    Hammond, Andrew; Galizi, Roberto; Kyrou, Kyros; Simoni, Alekos; Siniscalchi, Carla; Katsanos, Dimitris; Gribble, Matthew; Baker, Dean; Marois, Eric; Russell, Steven; Burt, Austin; Windbichler, Nikolai; Crisanti, Andrea; Nolan, Tony

    2016-01-01

    Gene drive systems that enable super-Mendelian inheritance of a transgene have the potential to modify insect populations over a timeframe of a few years. We describe CRISPR-Cas9 endonuclease constructs that function as gene drive systems in Anopheles gambiae, the main vector for malaria. We identified three genes (AGAP005958, AGAP011377 and AGAP007280) that confer a recessive female-sterility phenotype upon disruption, and inserted into each locus CRISPR-Cas9 gene drive constructs designed to target and edit each gene. For each targeted locus we observed a strong gene drive at the molecular level, with transmission rates to progeny of 91.4 to 99.6%. Population modeling and cage experiments indicate that a CRISPR-Cas9 construct targeting one of these loci, AGAP007280, meets the minimum requirement for a gene drive targeting female reproduction in an insect population. These findings could expedite the development of gene drives to suppress mosquito populations to levels that do not support malaria transmission.

  18. Evidence for X-linked introgression between molecular forms of Anopheles gambiae from Angola.

    Science.gov (United States)

    Choi, K S; Townson, H

    2012-06-01

    The M and S molecular forms of the African malaria vector Anopheles gambiae (Diptera: Culicidae) are morphologically identical incipient species in which reproductive isolation is incomplete, enabling low-level gene flow between forms. In an attempt to find differences between the M and S forms, sequence variation was studied at loci along the X chromosome in adult female An. gambiae from Angola. A high proportion of M form specimens from Angola (79% of the 456 X chromosomes sampled) were found to contain a 16-bp insertion in intron 4 of the X-linked GPRCCK1 locus, relative to the AgamP3 release of the An. gambiae PEST genome sequence. The insertion was in Hardy-Weinberg equilibrium in Angolan M form populations. The same insertion was found in all S form specimens examined, regardless of where in Africa they were sampled, but was absent from a sample of M form specimens collected in Ghana, Bioko and Mali. In M form specimens from Angola, there was an association between alleles at the GPRCCK1 locus and those at a microsatellite locus, AGXH678, close to the centromere of the X chromosome, with significant linkage disequilibrium between loci separated by 0.472 Mbp (P < 0.033). We show that the insertion results from introgression from the S form into the M form, rather than from the retention of an ancestral character. Gene flow from the S to M form could allow genes of adaptive value to be transferred, including those conferring insecticide resistance and others influencing ecology and behaviour, and thus malaria transmission and control. We discuss factors that may have led to this introgression event.

  19. Larvicidal properties of two asclepiadaceous plant species against the mosquito Anopheles arabiensis Patton (Diptera: Culicidae

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    Amal Elsayed Edriss

    2013-01-01

    Full Text Available Certain mosquito species are important vectors of fatal human diseases, among which Anopheles arabiensis is known to be associated with malaria transmission in different tropical and subtropical areas. Since chemical control of mosquitoes was linked with numerous drawbacks, like resistance development, the search for effective environmentally sound alternatives is urgently needed. Therefore, it was aimed by this study to evaluate some extracts prepared from two asclepiadaceous plants, viz., Solenostemma argel “Hargel” (seeds and leaves and Calotropis procera “Usher” (leaves and flowers, as natural larvicides against An. arabiensis. The main parameters included bioassays of treatments for knockdown and residual effects, besides phytochemical analysis of the tested extracts. The results revealed variable groups of secondary metabolites in the two plants, with S. argel seemed to be the richest one. Hence, S. argel extracts caused higher larval mortalities than those of C. procera. This could be ascribed to some potent secondary metabolites in the former plant, which needs further studies. Almost all the high concentrations of S. argel extracts exerted the highest knockdown effect (90% mortality after 24 h, which were comparable with those obtained by two standard insecticides. The highest doses of petroleum ether and water extracts of this plant also manifested significantly higher residual effects than the other extracts after three days following treatments, but were surpassed by the chemical insecticides thereafter. However, S. argel seed petroleum ether extract at 0.5% was the most effective of all botanicals up to three weeks of exposure. This extract needs to be evaluated under field conditions for proper exploitation as mosquito larvicide.

  20. Biochemical characterization of Anopheles gambiae SRPN6, a malaria parasite invasion marker in mosquitoes.

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    Chunju An

    Full Text Available Serine proteinase inhibitors of the serpin family are well known as negative regulators of hemostasis, thrombolysis and innate immune responses. Additionally, non-inhibitory serpins serve functions as chaperones, hormone transporters, or anti-angiogenic factors. In the African malaria mosquito, Anopheles gambiae s.s., at least three serpins (SRPNs are implicated in the innate immune response against malaria parasites. Based on reverse genetic and cell biological analyses, AgSRPN6 limits parasite numbers and transmission and has been postulated to control melanization and complement function in mosquitoes. This study aimed to characterize AgSRPN6 biophysically and determine its biochemical mode of action. The structure model of AgSRPN6, as predicted by I-Tasser showed the protein in the native serpin fold, with three central β-sheets, nine surrounding α-helices, and a protruding reactive center loop. This structure is in agreement with biophysical and functional data obtained from recombinant (r AgSRPN6, produced in Escherichia coli. The physical properties of purified rAgSRPN6 were investigated by means of analytical ultracentrifugation, circular dichroism, and differential scanning calorimetry tools. The recombinant protein exists predominantly as a monomer in solution, is composed of a mixture of α-helices and β-sheets, and has a mid-point unfolding temperature of 56°C. Recombinant AgSRPN6 strongly inhibited porcine pancreatic kallikrein and to a lesser extent bovine pancreatic trypsin in vitro. Furthermore, rAgSRPN6 formed inhibitory, SDS-stable, higher molecular weight complexes with prophenoloxidase-activating proteinase (PAP1, PAP3, and Hemolymph protein (HP6, which are required for melanization in the lepidopteran model organism, Manduca sexta. Taken together, our results strongly suggest that AgSRPN6 takes on a native serpin fold and is an inhibitor of trypsin-like serine proteinases.

  1. Transgenic Anopheles gambiae expressing an antimalarial peptide suffer no significant fitness cost.

    Science.gov (United States)

    McArthur, Clare C; Meredith, Janet M; Eggleston, Paul

    2014-01-01

    Mosquito-borne diseases present some of the greatest health challenges faced by the world today. In many cases, existing control measures are compromised by insecticide resistance, pathogen tolerance to drugs and the lack of effective vaccines. In light of these difficulties, new genetic tools for disease control programmes, based on the deployment of genetically modified mosquitoes, are seen as having great promise. Transgenic strains may be used to control disease transmission either by suppressing vector populations or by replacing susceptible with refractory genotypes. In practice, the fitness of the transgenic strain relative to natural mosquitoes will be a critical determinant of success. We previously described a transgenic strain of Anopheles gambiae expressing the Vida3 peptide into the female midgut following a blood-meal, which exhibited significant protection against malaria parasites. Here, we investigated the fitness of this strain relative to non-transgenic controls through comparisons of various life history traits. Experiments were designed, as far as possible, to equalize genetic backgrounds and heterogeneity such that fitness comparisons focussed on the presence and expression of the transgene cassette. We also employed reciprocal crosses to identify any fitness disturbance associated with inheritance of the transgene from either the male or female parent. We found no evidence that the presence or expression of the effector transgene or associated fluorescence markers caused any significant fitness cost in relation to larval mortality, pupal sex ratio, fecundity, hatch rate or longevity of blood-fed females. In fact, fecundity was increased in transgenic strains. We did, however, observe some fitness disturbances associated with the route of inheritance of the transgene. Maternal inheritance delayed male pupation whilst paternal inheritance increased adult longevity for both males and unfed females. Overall, in comparison to controls, there was

  2. Transgenic Anopheles gambiae expressing an antimalarial peptide suffer no significant fitness cost.

    Directory of Open Access Journals (Sweden)

    Clare C McArthur

    Full Text Available Mosquito-borne diseases present some of the greatest health challenges faced by the world today. In many cases, existing control measures are compromised by insecticide resistance, pathogen tolerance to drugs and the lack of effective vaccines. In light of these difficulties, new genetic tools for disease control programmes, based on the deployment of genetically modified mosquitoes, are seen as having great promise. Transgenic strains may be used to control disease transmission either by suppressing vector populations or by replacing susceptible with refractory genotypes. In practice, the fitness of the transgenic strain relative to natural mosquitoes will be a critical determinant of success. We previously described a transgenic strain of Anopheles gambiae expressing the Vida3 peptide into the female midgut following a blood-meal, which exhibited significant protection against malaria parasites. Here, we investigated the fitness of this strain relative to non-transgenic controls through comparisons of various life history traits. Experiments were designed, as far as possible, to equalize genetic backgrounds and heterogeneity such that fitness comparisons focussed on the presence and expression of the transgene cassette. We also employed reciprocal crosses to identify any fitness disturbance associated with inheritance of the transgene from either the male or female parent. We found no evidence that the presence or expression of the effector transgene or associated fluorescence markers caused any significant fitness cost in relation to larval mortality, pupal sex ratio, fecundity, hatch rate or longevity of blood-fed females. In fact, fecundity was increased in transgenic strains. We did, however, observe some fitness disturbances associated with the route of inheritance of the transgene. Maternal inheritance delayed male pupation whilst paternal inheritance increased adult longevity for both males and unfed females. Overall, in comparison to

  3. Confirmation of Anopheles (Anopheles calderoni Wilkerson, 1991 (Diptera: Culicidae in Colombia and Ecuador through molecular and morphological correlation with topotypic material

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    Ranulfo González

    2010-12-01

    Full Text Available The morphologically similar taxa Anopheles calderoni, Anopheles punctimacula, Anopheles malefactor and Anopheles guarao are commonly misidentified. Isofamilies collected in Valle de Cauca, Colombia, showed morphological characters most similar to An. calderoni, a species which has never previously been reported in Colombia. Although discontinuity of the postsubcostal pale spots on the costa (C and first radial (R1 wing veins is purportedly diagnostic for An. calderoni, the degree of overlap of the distal postsubcostal spot on C and R1 were variable in Colombian specimens (0.003-0.024. In addition, in 98.2% of larvae, seta 1-X was located off the saddle and seta 3-C had 4-7 branches in 86.7% of specimens examined. Correlation of DNA sequences of the second internal transcribed spacer and mtDNA cytochrome c oxidase subunit I gene (COI barcodes (658 bp of the COI gene generated from Colombian progeny material and wild-caught mosquitoes from Ecuador with those from the Peruvian type series of An. calderoni confirmed new country records. DNA barcodes generated for the closely related taxa, An. malefactor and An. punctimacula are also presented for the first time. Examination of museum specimens at the University of the Valle, Colombia, revealed the presence of An. calderoni in inland localities across Colombia and at elevations up to 1113 m.

  4. African water storage pots for the delivery of the Entomopathogenic fungus Metarhizium anisopliae to the Malaria vectors Anopheles gambiae s.s. and Anopheles funestus

    NARCIS (Netherlands)

    Farenhorst, M.; Farina, D.; Scholte, E.J.; Takken, W.; Hunt, R.H.; Coetzee, M.; Knols, B.G.J.

    2008-01-01

    We studied the use of African water storage pots for point source application of Metarhizium anisopliae against the malaria vectors Anopheles gambiae s.s. and An. funestus. Clay pots were shown to be attractive resting sites for male and female An. gambiae s.s. and were not repellent after impregnat

  5. Sperm quantity and size variation in un-irradiated and irradiated males of the malaria mosquito Anopheles arabiensis Patton

    NARCIS (Netherlands)

    Helinski, M.; Knols, B.G.J.

    2009-01-01

    Anopheles mosquitoes are important candidates for genetic control strategies. However, little is known about sperm quality and quantity as determinants of male reproductive success. In this study, sperm quantity and length variation were assessed in testes of un-irradiated and irradiated Anopheles a

  6. Comparative Studies on the Stenogamous and Eurygamous Behavior of Eight Anopheles Species of the Hyrcanus Group (Diptera: Culicidae in Thailand

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    Adulsak Wijit

    2016-03-01

    Full Text Available Establishment of laboratory colony is essential for mosquito-borne-disease research. Mating behavior of stenogamous Anopheles peditaeniatus and seven eurygamous species (Anopheles argyropus, Anopheles crawfordi, Anopheles nigerrimus, Anopheles nitidus, Anopheles paraliae (=An. lesteri, Anopheles pursati and Anopheles sinensis, were investigated and compared in this study. The self-mating success of adult mosquitoes in different size cages at two density resting surface (DRS values, 3.6 and 7.2, was statistically significant between stenogamous and eurygamous species. The results obtained from comparative measurements of specific characters in adult females (maxillary palpomere and antennal sensilla characters and males (wing and genitalia indicate those characters might influence the mating success of An. peditaeniatus in a small cage. The gonostylus of An. peditaeniatus was shorter than the eurygamous species. Additionally, the lower frequency of clasper movement and shorter mating time could be important mechanisms that control the stenogamous behavior of An. peditaeniatus. Interestingly, for the first time, a cluster of large sensilla coeloconica was recorded on the antenna of An. argyropus and An. peditaeniatus females. There was no statistically significant difference in the mean number per female of those large antennal sensilla coeloconica among six of the eurygamous species.

  7. KEANEKARAGAMAN JENIS NYAMUK Anopheles DI DAERAH DENGAN ATAU TANPA KEBUN SALAK DI KABUPATEN BANJARNEGARA

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    Dyah Widiastuti

    2012-11-01

    Full Text Available Anopheles has been known as vectors of malaria and filaria. A research which was aimed to evaluate the diversity of Anopheles mosquitoes at Salak and Non Salak Areas was conducted. This Research located in Banjarnegara Regency which lay in a mountainous in the middle of Central Java (7'12"- 7'31 N and 109'20"-109'45"W. The location was divided into two groups i.e. (1 Kendaga Village (Banjarmangu Subdistrict representing of Salak area, (2 Badakarya Village (Punggelan Subdistrict representing Non Salak area. Mosquitoes were collected by landing and resting collection methods. All mosquitoes were anaesthetized with chloroform and identified under microscope. Shanon-Weaver Index and Eveness Index were measured to evaluate the diversity of Anopheles mosquitoes. The results showed there were 6 species of Anopheles from both areas i.e. A. aconitus. A. balabacensis. A. barbirostris. A. kochi. A. vagus and A. maculatus. Result of examination by Independent Sample T-Test indicated that the diversity index value between two areas were not significantly different. Keywords: Anopheles, diversity, salakarea, non salakarea

  8. Malaria in Kakuma refugee camp, Turkana, Kenya: facilitation of Anopheles arabiensis vector populations by installed water distribution and catchment systems

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    Cetron Martin S

    2011-06-01

    Full Text Available Abstract Background Malaria is a major health concern for displaced persons occupying refugee camps in sub-Saharan Africa, yet there is little information on the incidence of infection and nature of transmission in these settings. Kakuma Refugee Camp, located in a dry area of north-western Kenya, has hosted ca. 60,000 to 90,000 refugees since 1992, primarily from Sudan and Somalia. The purpose of this study was to investigate malaria prevalence and attack rate and sources of Anopheles vectors in Kakuma refugee camp, in 2005-2006, after a malaria epidemic was observed by staff at camp clinics. Methods Malaria prevalence and attack rate was estimated from cases of fever presenting to camp clinics and the hospital in August 2005, using rapid diagnostic tests and microscopy of blood smears. Larval habitats of vectors were sampled and mapped. Houses were sampled for adult vectors using the pyrethrum knockdown spray method, and mapped. Vectors were identified to species level and their infection with Plasmodium falciparum determined. Results Prevalence of febrile illness with P. falciparum was highest among the 5 to 17 year olds (62.4% while malaria attack rate was highest among the two to 4 year olds (5.2/1,000/day. Infected individuals were spatially concentrated in three of the 11 residential zones of the camp. The indoor densities of Anopheles arabiensis, the sole malaria vector, were similar during the wet and dry seasons, but were distributed in an aggregated fashion and predominantly in the same zones where malaria attack rates were high. Larval habitats and larval populations were also concentrated in these zones. Larval habitats were man-made pits of water associated with tap-stands installed as the water delivery system to residents with year round availability in the camp. Three percent of A. arabiensis adult females were infected with P. falciparum sporozoites in the rainy season. Conclusions Malaria in Kakuma refugee camp was due mainly

  9. Pyrethroid resistance in an Anopheles funestus population from Uganda.

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    John C Morgan

    Full Text Available BACKGROUND: The susceptibility status of Anopheles funestus to insecticides remains largely unknown in most parts of Africa because of the difficulty in rearing field-caught mosquitoes of this malaria vector. Here we report the susceptibility status of the An. funestus population from Tororo district in Uganda and a preliminary characterisation of the putative resistance mechanisms involved. METHODOLOGY/PRINCIPAL FINDINGS: A new forced egg laying technique used in this study significantly increased the numbers of field-caught females laying eggs and generated more than 4000 F1 adults. WHO bioassays indicated that An. funestus in Tororo is resistant to pyrethroids (62% mortality after 1 h exposure to 0.75% permethrin and 28% mortality to 0.05% deltamethrin. Suspected DDT resistance was also observed with 82% mortality. However this population is fully susceptible to bendiocarb (carbamate, malathion (organophosphate and dieldrin with 100% mortality observed after exposure to each of these insecticides. Sequencing of a fragment of the sodium channel gene containing the 1014 codon conferring pyrethroid/DDT resistance in An. gambiae did not detect the L1014F kdr mutation but a correlation between haplotypes and resistance phenotype was observed indicating that mutations in other exons may be conferring the knockdown resistance in this species. Biochemical assays suggest that resistance in this population is mediated by metabolic resistance with elevated level of GSTs, P450s and pNPA compared to a susceptible strain of Anopheles gambiae. RT-PCR further confirmed the involvement of P450s with a 12-fold over-expression of CYP6P9b in the Tororo population compared to the fully susceptible laboratory colony FANG. CONCLUSION: This study represents the first report of pyrethroid/DDT resistance in An. funestus from East Africa. With resistance already reported in southern and West Africa, this indicates that resistance in An. funestus may be more widespread

  10. Anopheles gambiae Purine Nucleoside Phosphorylase: Catalysis, Structure, and Inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Taylor,E.; Rinaldo-Matthis, A.; Li, L.; Ghanem, M.; Hazleton, K.; Cassera, M.; Almo, S.; Schramm, V.

    2007-01-01

    The purine salvage pathway of Anopheles gambiae, a mosquito that transmits malaria, has been identified in genome searches on the basis of sequence homology with characterized enzymes. Purine nucleoside phosphorylase (PNP) is a target for the development of therapeutic agents in humans and purine auxotrophs, including malarial parasites. The PNP from Anopheles gambiae (AgPNP) was expressed in Escherichia coli and compared to the PNPs from Homo sapiens (HsPNP) and Plasmodium falciparum (PfPNP). AgPNP has kcat values of 54 and 41 s-1 for 2'-deoxyinosine and inosine, its preferred substrates, and 1.0 s-1 for guanosine. However, the chemical step is fast for AgPNP at 226 s-1 for guanosine in pre-steady-state studies. 5'-Deaza-1'-aza-2'-deoxy-1'-(9-methylene)-Immucillin-H (DADMe-ImmH) is a transition-state mimic for a 2'-deoxyinosine ribocation with a fully dissociated N-ribosidic bond and is a slow-onset, tight-binding inhibitor with a dissociation constant of 3.5 pM. This is the tightest-binding inhibitor known for any PNP, with a remarkable Km/Ki* of 5.4 x 107, and is consistent with enzymatic transition state predictions of enhanced transition-state analogue binding in enzymes with enhanced catalytic efficiency. Deoxyguanosine is a weaker substrate than deoxyinosine, and DADMe-Immucillin-G is less tightly bound than DADMe-ImmH, with a dissociation constant of 23 pM for AgPNP as compared to 7 pM for HsPNP. The crystal structure of AgPNP was determined in complex with DADMe-ImmH and phosphate to a resolution of 2.2 Angstroms to reveal the differences in substrate and inhibitor specificity. The distance from the N1' cation to the phosphate O4 anion is shorter in the AgPNP{center_dot}DADMe-ImmH{center_dot}PO4 complex than in HsPNP{center_dot}DADMe-ImmH{center_dot}SO4, offering one explanation for the stronger inhibitory effect of DADMe-ImmH for AgPNP.

  11. Man biting rate seasonal variation of malaria vectors in Roraima, Brazil

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    Fábio Saito Monteiro de Barros

    2007-06-01

    Full Text Available Malaria control has been directed towards regional actions where more detailed knowledge of local determinants of transmission is of primary importance. This is a short report on range distribution and biting indices for Anopheles darlingi and An. albitarsis during the dry and rainy season that follows river level variation in a savanna/alluvial forest malaria system area in the Northern Amazon Basin. Distribution range and adult biting indices were at their highest during the rainy season for both An. darlingi and An. albitarsis. During the rainy season the neighboring alluvial forest was extensively flooded. This coincided with highest rates in malaria transmission with case clustering near the river. As the river receded, anopheline distribution range and density decreased. This decrease in distribution and density corresponded to a malaria decrease in the near area. An exponential regression function was derived to permit estimations of An. darlingi distribution over specified distances. Anopheline spatio-temporal variations lead to uneven malaria case distribution and are of important implications for control strategies.

  12. Ivermectin mass drug administration to humans disrupts malaria parasite transmission in Senegalese villages.

    Science.gov (United States)

    Kobylinski, Kevin C; Sylla, Massamba; Chapman, Phillip L; Sarr, Moussa D; Foy, Brian D

    2011-07-01

    Ivermectin mass drug administration (MDA) to humans is used to control onchocerciasis and lymphatic filariasis. Recent field studies have shown an added killing effect of ivermectin MDA against malaria vectors. We report that ivermectin MDA reduced the proportion of Plasmodium falciparum infectious Anopheles gambiae sensu stricto (s.s.) in treated villages in southeastern Senegal. Ivermectin MDA is a different delivery method and has a different mode of action from current malaria control agents. It could be a powerful and synergistic new tool to reduce malaria transmission in regions with epidemic or seasonal malaria transmission, and the prevalence and intensity of neglected tropical diseases.

  13. Observaciones sobre Phlebotomus y Anopheles en el Callejon de Huaylas

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    Arístides Herrer

    1943-03-01

    Full Text Available Se han llevado a cabo observaciones entomológicas en relación con la verruga y el paludismo en la zona del Callejón de Huaylas comprendida desde la ciudad de Yuramarca a la de Huarás, prestando especial atención a la región del Cañón del Pato. Se indica, como resultados de tales observaciones, la presencia de las titiras: Phlebotomus verrucarum, P. peruensis, P. noguchii y una especia nueva, señalando detenidamente las localidades donde se las han encontrado. El P. verrucarum, principal trasmisor de la verruga, se halla a lo largo de toda la zona estudiada, siendo su número bastante reducido en la ciudad de Huarás. Desde Yuramarca hasta cerca de la ciudad de Carás se ha encontrado únicamente el Anopheles pseudopunctipennis, tanto larvas como adultos. Sus criaderos se encuentran principalmente en las márgenes del río Santa, en las de algunos afluentes de éste y en numerosos, manantiales.

  14. Resistance Mechanisms of Anopheles stephensi (Diptera: Culicidae to Temephos

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    Aboozar Soltani

    2015-10-01

    Full Text Available Background: Anopheles stephensi is a sub-tropical species and has been considered as one of the most important vector of human malaria throughout the Middle East and South Asian region including the malarious areas of southern Iran. Current reports confirmed An. stephensi resistance to temephos in Oman and India. However, there is no comprehensive research on mechanisms of temephos resistance in An. stephensi in the literature. This study was designed in order to clarify the enzymatic and molecular mechanisms of temephos resistance in this species.Methods: Profile activities of α- and ß-esterases, mixed function oxidase (MFO, glutathione-S-transferase (GST, insensitive acetylcholinesterase, and para-nitrophenyl acetate (PNPA-esterase enzymes were tested for An. stephensi strain with resistance ratio of 15.82 to temephos in comparison with susceptible strain.Results: Results showed that the mean activity of α-EST, GST and AChE enzymes were classified as altered indicating metabolic mechanisms have considerable role in resistance of An. stephensi to temephos. Molecular study using PCR-RFLP method to trace the G119S mutation in ACE-1 gene showed lack of the mutation responsible for organophosphate insecticide resistance in the temephos-selected strain of An. stephensi.Conclusion: This study showed that the altered enzymes but not targets site insensitivity of ACE-1 are responsible for temephos resistance in An. stephensi in south of Iran.

  15. Transcriptome analysis of Anopheles stephensi embryo using expressed sequence tags

    Indian Academy of Sciences (India)

    Kaustubh Gokhale; Deepak P Patil; Dhiraj P Dhotre; Rajnikant Dixit; Murlidhar J Mendki; Milind S Patole; Yogesh S Shouche

    2013-06-01

    Germ band retraction (GBR) stage is one of the important stages during insect development. It is associated with an extensive epithelial morphogenesis and may also be pivotal in generation of morphological diversity in insects. Despite its importance, only a handful of studies report the transcriptome repertoire of this stage in insects. Here, we report generation, annotation and analysis of ESTs from the embryonic stage (16–22 h post fertilization) of laboratory-reared Anopheles stephensi mosquitoes. A total of 1002 contigs were obtained upon clustering of 1140 high-quality ESTs, which demonstrates an astonishingly low transcript redundancy (12.1%). Putative functions were assigned only to 213 contigs (21%), comprising mainly of transcripts encoding protein synthesis machinery. Approximately 78% of the transcripts remain uncharacterized, illustrating a lack of sequence information about the genes expressed in the embryonic stages of mosquitoes. This study highlights several novel transcripts, which apart from insect development, may significantly contribute to the essential biological complexity underlying insect viability in adverse environments. Nonetheless, the generated sequence information from this work provides a comprehensive resource for genome annotation, microarray development, phylogenetic analysis and other molecular biology applications in entomology.

  16. Biolistic techniques for transfection of mosquito embryos (Anopheles gambiae).

    Science.gov (United States)

    Mialhe, E; Miller, L H

    1994-05-01

    To compensate for the extremely low rates of transformation by DNA microinjection into mosquito embryos of Anopheles gambiae, biolistic techniques were evaluated for introduction of DNA into large numbers of mosquito embryos. Biolistic experiments were first performed with a commercially available instrument intended for this purpose, according to the recommended procedure. The amount of DNA delivered was measured by the expression of luciferase under the control of the Drosophila heat shock protein (hsp) 70 promoter. Despite attempts to optimize biolistic parameters, the level of luciferase activity was low and highly variable. Two other methods of biolistic delivery of DNA-coated particles in aqueous suspension were then evaluated. One method used the gas explosion of the commercially available instrument (mentioned above) to drive an aqueous suspension of DNA-coated particles at high pressure. This method reproducibly increased the level of expression about 100-fold without greatly reducing embryo viability. Another method, which was recently described for plant transfection, uses lower pressure to deliver the aqueous suspension of DNA-coated particles. The level of expression of luciferase and the survival of embryos were equivalent to that obtained with the instrument modified for aqueous delivery of particles. Thus, both aqueous methods offer the advantages of reproducibly delivering more DNA to the embryos. Moreover, these methods could be suitable for delivering DNA mixed with proteins, such as restriction endonucleases and integrases, that may be destroyed by ethanol precipitation used in the standard PDS-1000/He method.

  17. [Anopheles funestus and rice agriculture in the Madagascar highlands].

    Science.gov (United States)

    Marrama, L; Rajaonarivelo, E; Laventure, S; Rabarison, P

    1995-01-01

    An exhaustive study of the potential habitats of Anopheles funestus was led during 1992 in Ankazobe on the Plateau of Madagascar, 95 km northwest of the capital Tananarive. The rice fields provide more than 90% of the positive habitats versus less than 10% for the nonhuman biotopes. Larva are especially abundant on the surfaces of the rice during grain head formation and maturation. The dense vegetation coverage provides them with shade and protection against predators. After harvesting, the follows can be filled with water and wild vegetation, and then also provide an important share of the habitats. The rice fields are omnipresent on the Plateau where they supply the basis of local alimentation. A. funestus then constitutes a serious risk for all of the villages. The role of the rice fields as habitats for A. funestus has already been noted in Kenya but in West Africa the rice fields do not host this species, even if this species is very abundant in the other types of habitats.

  18. Inactivation of Anopheles gambiae Glutathione Transferase ε2 by Epiphyllocoumarin

    Directory of Open Access Journals (Sweden)

    Patience Marimo

    2016-01-01

    Full Text Available Glutathione transferases (GSTs are part of a major family of detoxifying enzymes that can catalyze the reductive dehydrochlorination of dichlorodiphenyltrichloroethane (DDT. The delta and epsilon classes of insect GSTs have been implicated in conferring resistance to this insecticide. In this study, the inactivation of Anopheles gambiae GSTε2 by epiphyllocoumarin (Tral 1 was investigated. Recombinant AgGSTε2 was expressed in Escherichia coli cells containing a pET3a-AGSTε2 plasmid and purified by affinity chromatography. Tral 1 was shown to inactivate GSTε2 both in a time-dependent manner and in a concentration-dependent manner. The half-life of GSTε2 in the presence of 25 μM ethacrynic acid (ETA was 22 minutes and with Tral 1 was 30 minutes, indicating that Tral 1 was not as efficient as ETA as an inactivator. The inactivation parameters kinact and KI were found to be 0.020 ± 0.001 min−1 and 7.5 ± 2.1 μM, respectively, after 90 minutes of incubation. Inactivation of GSTε2 by Tral 1 implies that Tral 1 covalently binds to this enzyme in vitro and would be expected to exhibit time-dependent effects on the enzyme in vivo. Tral 1, therefore, would produce irreversible effects when used together with dichlorodiphenyltrichloroethane (DDT in malaria control programmes where resistance is mediated by GSTs.

  19. FAUNA DAN TEMPAT PERKEMBANGBIAKAN POTENSIAL NYAMUK Anopheles spp DI KECAMATAN MAYONG, KABUPATEN JEPARA, JAWA TENGAH

    Directory of Open Access Journals (Sweden)

    Mardiana Mardiana

    2012-10-01

    Full Text Available Malaria masih merupakan masalah kesehatan masyarakat di beberapa daerah pedesaan di Jawa Tengah. Usaha pemberantasan malaria telah dilakukan oleh program baik secara kimiawi maupun hayati, guna memutuskan rantai penularan. Penelitian fauna dan tempat perindukan potensial nyamuk Anopheles telah dilakukan di Desa Buaran, Kecamatan Mayong I, Kabupaten Jepara, Jawa Tengah. Penangkapan nyamuk dengan umpan orang dilakukan di dalam dan di luar rumah pada malam hari dari pukul 18.00-24.00 yang masing-masing dilakukan oleh dua orang kolektor. Penangkapan nyamuk yang istirahat di dalam dan luar rumah (vegetasi pada pagi hari dilakukan pukul 06.00-08.00, yang dilakukan satu bulan 4 kali penangkapan selama 6 bulan. Pengambilan larva dan pupa dilakukan dari pukul 06.00-08.00 pagi di tempat genangan air dan sawah serta tempat yang potensial diduga sebagai perindukan Anopheles. Hasil penangkapan selama 6 bulan, diperoleh 1248 ekor nyamuk Anopheles yang terdiri dari 6 spesies yaitu: An. aconitus 442 ekor (35,42%, An. annularis 69 ekor (5,53% , An. barbirostris 30 ekor (2,4%, An. maculatus 2 ekor (0,16%, An. tesselatus 5 ekor (0,40% dan An. vagus 700 ekor (56,09%. Populasi aconitus ditemukan dari penangkapan di luar rumah, pada bulan Juli (56,40%, Agustus (42,80% dan Oktober (39,50% sedangkan pada bulan Mei (52,9%, Juni (44% dan September (50,40% dari penangkapan di kandang sapi. Pengambilan larva dan pupa Anopheles dilakukan di tempat habitat seperti sawah yang pada bulan Aguslus terbanyak ditemukan sebesar 85 (1.70, di sungai ditemukan hanya 4 (0.08 serta di genangan air bekas telapak kaki/kobokan ditemukan sebesar 6 (0.12. Ternyata tempat perindukan yang potensial larva Anopheles pada musim kemarau, ditemukan pada sungai yang ditanami kangkung oleh masyarakat selempat. Kata kunci: Fauna, tempat perindukan, Anopheles, vector

  20. Paridade de Anopheles cruzii em Floresta Ombrófila Densa no Sul do Brasil Anopheles cruzii parity in dense rain forest in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Ana Caroline Dalla Bona

    2006-12-01

    Full Text Available OBJETIVO: Conhecer a paridade e desenvolvimento ovariano da espécie Anopheles cruzii, durante os períodos estacionais. MÉTODOS: As capturas foram realizadas quinzenalmente, no período matutino, de abril/2004 a abril/2005, no Parque Estadual do Palmito, município de Paranaguá litoral do Estado do Paraná. Mosquitos adultos foram capturados usando a técnica pouso homem. As dissecções foram feitas utilizando-se a técnica de Detinova e de Polovodova e a avaliação do desenvolvimento folicular, segundo os critérios de Christophers e Mer. RESULTADOS: Foram dissecadas 208 fêmeas de Anopheles cruzii. A maioria das fêmeas dissecadas nas estações eram nulíparas. Sendo que 14,4% eram nulíparas com folículo além do estádio II de Christophers & Mer, o que evidencia o exercício da hematofagia previamente à primeira oviposição. Observou-se que as populações de Anopheles cruzii são constituídas de indivíduos jovens, talvez em razão da alta mortalidade de fêmeas paridas. CONCLUSÕES: A provável discordância gonotrófica das fêmeas dissecadas é importante do ponto de vista epidemiológico, considerando que a fêmea pode procurar mais de um hospedeiro para completar a maturação dos seus ovos.OBJECTIVE: To determine the parity and ovarian development of Anopheles cruzii species during the seasons. METHODS: Collections were carried out fortnightly in the morning in the Palmito State Park in the municipality of Paranaguá, Southern Brazil, between April 2004 and April 2005. Adult mosquitoes were captured using human landing rate. Dissections were performed using Detinova's and Polovodova's methods and follicular development was assessed following Christophers and Mer's criteria. RESULTS: A total of 208 specimens of Anopheles cruzii were dissected. Most females dissected were nulliparous in the seasons; 14.4% of them were found to be nulliparous above Christophers and Mer's stage II, which shows previous blood meal prior to the

  1. HIV Transmission

    Science.gov (United States)

    ... Abroad Treatment Basic Statistics Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... on HIV Syndicated Content Website Feedback HIV/AIDS HIV Transmission Language: English Transmisión del VIH Recommend on ...

  2. Acetylcholinesterases from the Disease Vectors Aedes aegypti and Anopheles gambiae: Functional Characterization and Comparisons with Vertebrate Orthologues.

    Directory of Open Access Journals (Sweden)

    Cecilia Engdahl

    Full Text Available Mosquitoes of the Anopheles (An. and Aedes (Ae. genus are principal vectors of human diseases including malaria, dengue and yellow fever. Insecticide-based vector control is an established and important way of preventing transmission of such infections. Currently used insecticides can efficiently control mosquito populations, but there are growing concerns about emerging resistance, off-target toxicity and their ability to alter ecosystems. A potential target for the development of insecticides with reduced off-target toxicity is the cholinergic enzyme acetylcholinesterase (AChE. Herein, we report cloning, baculoviral expression and functional characterization of the wild-type AChE genes (ace-1 from An. gambiae and Ae. aegypti, including a naturally occurring insecticide-resistant (G119S mutant of An. gambiae. Using enzymatic digestion and liquid chromatography-tandem mass spectrometry we found that the secreted proteins were post-translationally modified. The Michaelis-Menten constants and turnover numbers of the mosquito enzymes were lower than those of the orthologous AChEs from Mus musculus and Homo sapiens. We also found that the G119S substitution reduced the turnover rate of substrates and the potency of selected covalent inhibitors. Furthermore, non-covalent inhibitors were less sensitive to the G119S substitution and differentiate the mosquito enzymes from corresponding vertebrate enzymes. Our findings indicate that it may be possible to develop selective non-covalent inhibitors that effectively target both the wild-type and insecticide resistant mutants of mosquito AChE.

  3. Monoclonal antibodies AC-43 and AC-29 disrupt Plasmodium vivax development in the Indian malaria vector Anopheles culicifacies (Diptera: culicidae)

    Indian Academy of Sciences (India)

    Manoj Chugh; B R Gulati; S K Gakhar

    2010-03-01

    A repertoire of monoclonal antibodies (mAbs) was generated against the midgut proteins of Anopheles culicifacies mosquitoes. The mAbs AC-43 and AC-29 significantly inhibited Plasmodium vivax development inside the mosquito midgut. The number of oocysts that developed was reduced by 78.6% when mosquitoes ingested a combination of these two mAbs along with the blood meal. AC-43 mAb binds to the epitope common in 97, 80 and 43 kDa polypeptides from the midgut protein extract, as indicated by western blot analysis. Similarly, the mAb AC-29 recognized 52, 44, 40 and 29 kDa polypeptides. These female midgut-specific polypeptides are shared between An. culicifacies and An. stephensi, two major vectors of malaria in India. Deglycosylation assays revealed that -linked carbohydrates are the major components in epitopes corresponding to AC-43 and AC-29. Gold particle labelling revealed that both these mAbs preferentially bind to glycoproteins at the apical microvilli and the microvillus-associated network present inside transverse sections of the gut epithelium. These regions are particularly known to have receptors for ookinetes, which enable them to cross this epithelial barrier and provide them with certain necessary chemicals or components for further development into oocysts. Therefore, these glycoproteins appear to be potential candidates for a vectordirected transmission-blocking vaccine (TBV).

  4. STATUS OF INSECTICIDE RESISTANCE IN ANOPHELES CULICIFACIES (DIPTERA: CULICIDAE IN GHASREGHAND DISTRICT, SISTAN AND BALUCHISTAN PROVINCE, IRAN, (1997

    Directory of Open Access Journals (Sweden)

    H. Vatandoost

    1999-08-01

    Full Text Available Anopheles culicifacies s.l. plays an important role In transmission of malaria in Sistan and Baluchistan province, southeastern Iran. Adult susceptibility test on fieltt-collccled mosquitoes was conducted in Ohasreghand district. WHO diagnostic test procedures revealed that adult females were resistant to 0.4% dieUirin (mortality 64.5 ± 3.13, tolerant to 0.1% propoxur (mortality 88.5 ± 2.24 and susceptible to 4% DDT (mortality 98.75 ± 0.8. 5% malathion (mortality 100%, 0.1% bendiocarb (mortality 98.86 ± 0.7, 0.25% pcrmcthrin (mortality 98.4 ± 0.1, ami 0.1% lamhdacyhalothrin (mortality 100%. Malathion and lamhdacyhalothrin had the highest efficacy against this species when they were exposed at the diagnostic dose for 1 hour followed by a 24 hour recovery period. DieUirin, DDT a nil malathion had been used for malaria control as an indoor residual spraying. Tlic implication of these findings in the control programme is discussed.

  5. Repellent, irritant and toxic effects of 20 plant extracts on adults of the malaria vector Anopheles gambiae mosquito.

    Science.gov (United States)

    Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

    2013-01-01

    Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged.

  6. Acetylcholinesterases from the Disease Vectors Aedes aegypti and Anopheles gambiae: Functional Characterization and Comparisons with Vertebrate Orthologues.

    Science.gov (United States)

    Engdahl, Cecilia; Knutsson, Sofie; Fredriksson, Sten-Åke; Linusson, Anna; Bucht, Göran; Ekström, Fredrik

    2015-01-01

    Mosquitoes of the Anopheles (An.) and Aedes (Ae.) genus are principal vectors of human diseases including malaria, dengue and yellow fever. Insecticide-based vector control is an established and important way of preventing transmission of such infections. Currently used insecticides can efficiently control mosquito populations, but there are growing concerns about emerging resistance, off-target toxicity and their ability to alter ecosystems. A potential target for the development of insecticides with reduced off-target toxicity is the cholinergic enzyme acetylcholinesterase (AChE). Herein, we report cloning, baculoviral expression and functional characterization of the wild-type AChE genes (ace-1) from An. gambiae and Ae. aegypti, including a naturally occurring insecticide-resistant (G119S) mutant of An. gambiae. Using enzymatic digestion and liquid chromatography-tandem mass spectrometry we found that the secreted proteins were post-translationally modified. The Michaelis-Menten constants and turnover numbers of the mosquito enzymes were lower than those of the orthologous AChEs from Mus musculus and Homo sapiens. We also found that the G119S substitution reduced the turnover rate of substrates and the potency of selected covalent inhibitors. Furthermore, non-covalent inhibitors were less sensitive to the G119S substitution and differentiate the mosquito enzymes from corresponding vertebrate enzymes. Our findings indicate that it may be possible to develop selective non-covalent inhibitors that effectively target both the wild-type and insecticide resistant mutants of mosquito AChE.

  7. Interrupting malaria transmission by genetic manipulation of anopheline mosquitoes

    Directory of Open Access Journals (Sweden)

    Marcelo Jacobs-Lorena

    2003-09-01

    Full Text Available Malaria ranks among the deadliest infectious diseases that kills more than one million persons everyyear. The mosquito is an obligatory vector for malaria transmission. In the mosquito, Plasmodiumundergoes a complex series of developmental events that includes transformation into severaldistinct morphological forms and the crossing of two different epithelia—midgut and salivarygland. Circumstantial evidence suggests that crossing of the epithelia requires specific interactionsbetween Plasmodium and epithelial surface molecules. By use of a phage display library we haveidentified a small peptide-SM1—that binds to the surfaces of the mosquito midgut and salivaryglands. Transgenic Anopheles stephensi mosquitoes expressing a SM1 tetramer from a bloodinducibleand gut-specific promoter are substantially impaired in their ability to sustain parasitedevelopment and transmission. A second effector gene, phospholipase A2, also impairs parasitetransmission in transgenic mosquitoes. These findings have important implications for the developmentof new strategies for malaria control.

  8. The dance of male Anopheles gambiae in wild mating swarms.

    Science.gov (United States)

    Butail, Sachit; Manoukis, Nicholas C; Diallo, Moussa; Ribeiro, José M C; Paley, Derek A

    2013-05-01

    An important element of mating in the malaria vector Anopheles gambiae Giles in nature is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and insemination is generally believed to occur. In this study, we mathematically characterize the oscillatory movement of male An. gambiae in terms of an established individual-based mechanistic model that parameterizes the attraction of a mosquito toward the center of the swarm using the natural frequency of oscillation and the resistance to its motion, characterized by the damping ratio. Using three-dimensional trajectory data of ten wild mosquito swarms filmed in Mali, Africa, we show two new results for low and moderate wind conditions, and indicate how these results may vary in high wind. First, we show that in low and moderate wind the vertical component of the mosquito motion has a lower frequency of oscillation and higher damping ratio than horizontal motion. In high wind, the vertical and horizontal motions are similar to one another and the natural frequencies are higher than in low and moderate wind. Second, we show that the predicted average disagreement in the direction of motion of swarming mosquitoes moving randomly is greater than the average disagreement we observed between each mosquito and its three closest neighbors, with the smallest level of disagreement occurring for the nearest neighbor in seven out of 10 swarms. The alignment of the direction of motion between nearest neighbors is the highest in high wind. This result provides evidence for flight-path coordination between swarming male mosquitoes.

  9. Genetic population structure of Anopheles gambiae in Equatorial Guinea

    Directory of Open Access Journals (Sweden)

    Caccone Adalgisa

    2007-10-01

    Full Text Available Abstract Background Patterns of genetic structure among mosquito vector populations in islands have received particular attention as these are considered potentially suitable sites for experimental trials on transgenic-based malaria control strategies. In this study, levels of genetic differentiation have been estimated between populations of Anopheles gambiae s.s. from the islands of Bioko and Annobón, and from continental Equatorial Guinea (EG and Gabon. Methods Genotyping of 11 microsatellite loci located in chromosome 3 was performed in three island samples (two in Bioko and one in Annobón and three mainland samples (two in EG and one in Gabon. Four samples belonged to the M molecular form and two to the S-form. Microsatellite data was used to estimate genetic diversity parameters, perform demographic equilibrium tests and analyse population differentiation. Results High levels of genetic differentiation were found between the more geographically remote island of Annobón and the continent, contrasting with the shallow differentiation between Bioko island, closest to mainland, and continental localities. In Bioko, differentiation between M and S forms was higher than that observed between island and mainland samples of the same molecular form. Conclusion The observed patterns of population structure seem to be governed by the presence of both physical (the ocean and biological (the M-S form discontinuity barriers to gene flow. The significant degree of genetic isolation between M and S forms detected by microsatellite loci located outside the "genomic islands" of speciation identified in A. gambiae s.s. further supports the hypothesis of on-going incipient speciation within this species. The implications of these findings regarding vector control strategies are discussed.

  10. The Susceptibility and Behavioral Response of Anopheles Albimanus Weidemann and Anopheles Vestitipennis Dyar and Knab (Diptera: Culicidae) to Insecticides in Northern Belize, Central America

    Science.gov (United States)

    1999-01-01

    33:205-211. 66 Marquetti, M.C.., A. Navarro and JA Bisset. 1990. Estudio de la actividad hematofagica de Anopheles vestitipennis Dyar & Knab, 1906...Garcia. 1986. Estudio estaeional de sitios de reposo de anophelinos (Diptera: Culicidae). [Studies of the resting places ofanophelines (Diptera...Anofelinos mexicanos . Taxonomia y distribucion [Mexican anophelines. Taxonomy and distribution]. Mex.., D.F.., ecr. Salubr. Assist. CNEP/SS~ 181 pp

  11. Transcending Transmission

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Trittin, Hannah

    2013-01-01

    Purpose – Extant research on corporate social responsibility (CSR) communication primarily relies on a transmission model of communication that treats organizations and communication as distinct phenomena. This approach has been criticized for neglecting the formative role of communication...... in the emergence of organizations. This paper seeks to propose to reconceptualize CSR communication by drawing on the “communication constitutes organizations” (CCO) perspective. Design/methodology/approach – This is a conceptual paper that explores the implications of switching from an instrumental...

  12. Molecular identification of a myosuppressin receptor from the malaria mosquito Anopheles gambiae

    DEFF Research Database (Denmark)

    Schöller, Susanne; Belmont, Martin; Cazzamali, Giuseppe

    2005-01-01

    The insect myosuppressins (X1DVX2HX3FLRFamide) are neuropeptides that generally block insect muscle activities. We have used the genomic sequence information from the malaria mosquito Anopheles gambiae Genome Project to clone a G protein-coupled receptor that was closely related to the two previo...

  13. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya.

    Science.gov (United States)

    Wanjala, Christine L; Mbugi, Jernard P; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A; Atieli, Harrysone E; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

    2015-12-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non-pyrethroid-based vector control tools may be preferable for malaria prevention in this region.

  14. Biology and Description of the Larva and Pupa of Anopheles (Cellia) elegans James (1903),

    Science.gov (United States)

    1983-01-01

    Ramakrishnan. 1963. Experimental susceptibility of Anophe line mosquitoes to simian malaria in N the Nilgiris , Madras State, South India. Indian J...simian malaria in the Nilgiris , Madras State, India. Indian J. Malariol. 17:243-247. Colless, D.H. 1956. The Anopheles leucoph ,rus group. Trans. R

  15. Batkoa apiculata (Thaxter) Humber affecting Anopheles (Diptera: Culicidae) in the municipality of Una, Southern Bahia, Brazil

    Science.gov (United States)

    Surveys for fungal pathogens affecting adult mosquitoes from the genus Anopheles were conducted in flooded and swamp-like natural breeding sites near residences in the center and suburbs of the city of Una as well as the nearby village of Outeiro in southern Bahia. Surveys of 54 mosquito breeding si...

  16. Behavioural response of the malaria vector Anopheles gambiae to host plant volatiles and synthetic blends

    Science.gov (United States)

    Sugar feeding is critical for survival of malaria vectors and, although discriminative plant feeding previously has been shown to occur in Anopheles gambiae s.s., little is known about the cues mediating attraction to these plants. In this study, we investigated the role of olfaction in An. gambiae ...

  17. Effect of larval crowding on mating competitiveness of Anopheles gambiae mosquitoes

    NARCIS (Netherlands)

    Ng'habi, K.R.; John, B.; Nkwengulila, G.; Knols, B.G.J.; Killeen, G.F.; Ferguson, H.M.

    2005-01-01

    Background: The success of sterile or transgenic Anopheles for malaria control depends on their mating competitiveness within wild populations. Current evidence suggests that transgenic mosquitoes have reduced fitness. One means of compensating for this fitness deficit would be to identify environme

  18. Anopheles (Nyssorhynchus) Pictipennis: A New Mosquito Record from the Atacama Region of Northern Chile

    Science.gov (United States)

    2008-01-01

    Santiago, this species rarely feeds on humans, but it is highly attracted to domestic animals (Linthicum 1988). In this paper, we report An. (N...Mosq Control Assoc 12:619-626. Neghme AR. 1943. Contribucion a la biologia del Anopheles pictipenllis (Philippi, 1865). I. Communica- cion

  19. Egg hatching, larval movement and larval survival of the malaria vector Anopheles gambiae in desiccating habitats

    NARCIS (Netherlands)

    Koenraadt, C.J.M.; Paaijmans, K.P.; Githeko, A.K.; Knols, B.G.J.; Takken, W.

    2003-01-01

    Background - Although the effects of rainfall on the population dynamics of the malaria vector Anopheles gambiae have been studied in great detail, the effects of dry periods on its survival remain less clear. Methods - The effects of drying conditions were simulated by creating desiccated habitats,

  20. Effectiveness of synthetic versus natural human volatiles as attractants for Anopheles gambiae (Diptera: Culicidae) sensu stricto

    NARCIS (Netherlands)

    Smallegange, R.C.; Knols, B.G.J.; Takken, W.

    2010-01-01

    Females of the African malaria vector, Anopheles gambiae Giles sensu stricto, use human volatiles to find their blood-host. Previous work has shown that ammonia, lactic acid, and aliphatic carboxylic acids significantly affect host orientation and attraction of this species, In the current study, th

  1. Inhibition of host-seeking response and olfactory responsiveness in Anopheles gambiae following blood feeding

    NARCIS (Netherlands)

    Takken, W.; Loon, van J.J.A.; Adam, W.

    2001-01-01

    The effect of a single blood meal on the host-seeking response of Anopheles gambiae was investigated in the laboratory using a behavioural bioassay, whereas possible changes at the chemosensory level were monitored using electroantennogram recording (EAG). To avoid the possible confounding effect of

  2. Control of pyrethroid-resistant Anopheles gambiae and Culex quinquefasciatus mosquitoes with chlorfenapyr in Benin

    NARCIS (Netherlands)

    N'Guessan, R.; Boko, P.; Odjo, A.; Knols, B.G.J.; Akogbeto, M.; Rowland, M.

    2009-01-01

    Objective To compare the efficacy of chlorfenapyr applied on mosquito nets and as an indoor residual spray against populations of Anopheles gambiae and Culex quinquefasciatus in an area of Benin that shows problematic levels of pyrethroid resistance. Method Eight-week trial conducted in experimental

  3. Olfaction in the malaria mosquito Anopheles gambiae : Electrophysiology and identification of kairomones

    NARCIS (Netherlands)

    Meijerink, J.

    1999-01-01

    Female mosquitoes of the species Anopheles gambiae Giles sensu stricto are important vectors of human malaria in Africa. It is generally assumed that they locate their human host by odours. These odours are detected by olfactory receptor neurons situated within cuticular extensions on the antenna. T

  4. Feeding and survival of the malaria vector Anopheles gambiae on plants growing in Kenia

    NARCIS (Netherlands)

    Impoinvil, D.E.; Kongere, J.O.; Foster, W.A.; Njiru, B.N.; Killeen, G.F.; Githure, J.I.; Beier, J.C.; Hassanali, A.; Knols, B.G.J.

    2004-01-01

    The propensity of the malaria vector mosquito Anopheles gambiae Giles (Diptera: Culicidae) to ingest sugars from various plants, and subsequent survival rates, were assessed with laboratory-reared males and females offered eight species of plants commonly cultivated and/or growing wild in western Ke

  5. Using a near-infrared spectrometer to estimate the age of Anopheles mosquitoes exposed to pyrethroids

    Science.gov (United States)

    We report on the accuracy of using near-infrared spectroscopy (NIRS) to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as ,7 or $7 d ol...

  6. [Radiosensitivity curve of different stages of spermatogenesis of Anopheles atroparvus (Diptera:Nematocera)].

    Science.gov (United States)

    Lecis, A R; Figus, V; Santarini, C

    1975-01-01

    In order to obtain a dose-hatchability curve for irradiated spermatogenetic stages of Anopheles atroparvus, we have irradiated with the same dose "4500 r" young fourth larval stages, old fourth larval stages, nymphae and adult males. Those different stages represent different phases of spermatogenesis. The peak of radiosensitivity for embryonic mortality, was found in spermatids, lowest appeared in spermatogonies.

  7. Ecology of Anopheles Stephensi in a Malarious Area, Southeast of Iran

    Directory of Open Access Journals (Sweden)

    Norair Piazak

    2012-01-01

    Full Text Available District of Jiroft is situated in south-east of Iran which is one of the malarious regions. Anopheles stephensi is considered as one of the main malaria vector in this region. Ecology of this species was studied in the area to understand its vector behavior for implementation of effective vector control measures. Different methods like total catch, pit shelter, night bite collection on human and animal, larval dipping methods were used for species identification, seasonal activity, anthropophilic index and egg morphological characteristics. Anthropophilicity index was assessed by ELISA test. Activity of Anopheles species started at the beginning of April, and its peak occurs in late spring. The larvae were found in the river bed with pools, stagnant streams, slow foothill streams, temporary pools, and slowly moving water with and without vegetation, drainage containers of air conditioner and palm irrigation canals. From different methods of adult collection, it was found that spray sheet collection is the appropriate method. ELISA testing of 144 blood meals of females revealed the anthropophilicity of 11.8% indicating host preference on animal, mainly cow. Ridge length and their number on the egg floats confirmed Anopheles stephensi mysorensis form. This study showed that Anopheles stephensi is the main vector of malaria in the region, although some other species may play a role. Our findings could provide a valuable clue for epidemiology and control of malaria in the southeast of Iran.

  8. Human skin emanations in the host-seeking behaviour of the malaria mosquito Anopheles gambiae

    NARCIS (Netherlands)

    Braks, M.A.H.

    1999-01-01

    Malaria is an infectious disease caused by a parasite ( Plasmodium spp.) that is transmitted between human individuals by mosquitoes, belonging to the order of insects, Diptera, family of Culicidae (mosquitoes) and genus of Anopheles (malaria mosquitoes). Mosquitoes feed on humans (and other animals

  9. Improvement of a synthetic lure for Anopheles gambiae using compounds produced by human skin microbiota

    NARCIS (Netherlands)

    Verhulst, N.O.; Mbadi, P.A.; Bukovinszkine-Kiss, G.; Mukabana, W.R.; Loon, van J.J.A.; Takken, W.; Smallegange, R.C.

    2011-01-01

    Background - Anopheles gambiae sensu stricto is considered to be highly anthropophilic and volatiles of human origin provide essential cues during its host-seeking behaviour. A synthetic blend of three human-derived volatiles, ammonia, lactic acid and tetradecanoic acid, attracts A. gambiae. In addi

  10. Was Anopheles donaldi a vector of malaria in Kuala Lumpur, Malaysia, in the past?

    Science.gov (United States)

    Reid, J A

    1980-01-01

    Anopheles donaldi Reid, a member of the A. barbirostris species group, is a vector of human filariasis and probably malaria. The discovery of some old specimens of this species, collected in Kuala Lumpur town where it no longer occurs, together with evidence from the literature about past malaria in the town, suggest that donaldi may have played a part in transmitting that malaria.

  11. Larvicidal effects of a neem (Azadirachta indica) oil formulation on the malaria vector Anopheles gambiae

    NARCIS (Netherlands)

    Okumu, F.O.; Knols, B.G.J.; Fillinger, U.

    2007-01-01

    Background - Larviciding is a key strategy used in many vector control programmes around the world. Costs could be reduced if larvicides could be manufactured locally. The potential of natural products as larvicides against the main African malaria vector, Anopheles gambiae s.s was evaluated. Method

  12. Species-specific chemosensory gene expression in the olfactory organs of the malaria vector Anopheles gambiae

    NARCIS (Netherlands)

    Hodges, Theresa K.; Cosme, Luciano V.; Athrey, Giridhar; Pathikonda, Sharmila; Takken, Willem; Slotman, Michel A.

    2014-01-01

    Background: The malaria mosquito Anopheles gambiae has a high preference for human hosts, a characteristic that contributes greatly to its capacity for transmitting human malaria. A sibling species, An. quadriannulatus, has a quite different host preference and feeds mostly on bovids. For this re

  13. Population dynamics of sporogony for Plasmodium vivax parasites from western Thailand developing within three species of colonized Anopheles mosquitoes

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    Sattabongkot Jetsumon

    2006-08-01

    Full Text Available Abstract Background The population dynamics of Plasmodium sporogony within mosquitoes consists of an early phase where parasite abundance decreases during the transition from gametocyte to oocyst, an intermediate phase where parasite abundance remains static as oocysts, and a later phase where parasite abundance increases during the release of progeny sporozoites from oocysts. Sporogonic development is complete when sporozoites invade the mosquito salivary glands. The dynamics and efficiency of this developmental sequence were determined in laboratory strains of Anopheles dirus, Anopheles minimus and Anopheles sawadwongporni mosquitoes for Plasmodium vivax parasites circulating naturally in western Thailand. Methods Mosquitoes were fed blood from 20 symptomatic Thai adults via membrane feeders. Absolute densities were estimated for macrogametocytes, round stages (= female gametes/zygotes, ookinetes, oocysts, haemolymph sporozoites and salivary gland sporozoites. From these census data, five aspects of population dynamics were analysed; 1 changes in life-stage prevalence during early sporogony, 2 kinetics of life-stage formation, 3 efficiency of life-stage transitions, 4 density relationships between successive life-stages, and 5 parasite aggregation patterns. Results There was no difference among the three mosquito species tested in total losses incurred by P. vivax populations during early sporogony. Averaged across all infections, parasite populations incurred a 68-fold loss in abundance, with losses of ca. 19-fold, 2-fold and 2-fold at the first (= gametogenesis/fertilization, second (= round stage transformation, and third (= ookinete migration life-stage transitions, respectively. However, total losses varied widely among infections, ranging from 6-fold to over 2,000-fold loss. Losses during gametogenesis/fertilization accounted for most of this variability, indicating that gametocytes originating from some volunteers were more fertile than

  14. Larvicidal property of green synthesized silver nanoparticles against vector mosquitoes (Anopheles stephensi and Aedes aegypti

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    Rajamani Bhuvaneswari

    2016-10-01

    Full Text Available Mosquito vectors spread severe human diseases which lead to millions of deaths every year. Vector management is ultimately aimed to develop the health of every individual’s life by reducing the mosquito diversity. Control of vectors in growing counties is an important issue with various aspects. The advancement of green nanotechnology will attribute the solution for vector controlling policy. To identify the larvicidal property of silver nanoparticles (AgNPs using Belosynapsis kewensis (B. kewensis leaf extract against the Anopheles stephensi (A. stephensi and Aedes aegypti (A. aegypti in vitro study (LC50 and LC90 was analyzed. The synthesized AgNPs were characterized by UV–vis. (Ultraviolet–visible spectroscopy, FTIR (Fourier Transform Infra Red spectroscopy, TEM (Transmission Electron Microscopy, and XRD (X-ray Diffraction. Green AgNPs have a maximum absorption at 411 nm. The FTIR spectrum showed prominent peaks in (3863.55, 3759.02, 3361.01, 2926.81, 1575.12, 1388.16, 1034.79, 821.96, 717.07, 590.92, 534.32 and 472.42 cm−1 in the region of 4000–400 cm−1. The XRD peaks shown at 27.4°, 35.90°, 37.20°, 51.23° and 71.10° correspond to (311, (100, (101, (104 and (006 planes for face centered cubic (FCC. The TEM image showed the NPs with an average size of 24 ± 1.6 nm. In vitro larvicidal activity of AgNPs was used against the fourth instar of A. stephensi and A. aegypti. The LC50 and LC90 values of AgNPs showed to be effective against A. stephensi (LC50 = 78.4; LC90 = 144.7 ppm followed by A. aegypti (LC50 = 84.2; LC90 = 117.3 ppm. These results recommend that the green synthesized AgNPs have a potential to be used as a candidate for the control of A. stephensi and A. aegypti through eco-friendly and cost effective approach.

  15. Comparative analyses reveal discrepancies among results of commonly used methods for Anopheles gambiaemolecular form identification

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    Pinto João

    2011-08-01

    Full Text Available Abstract Background Anopheles gambiae M and S molecular forms, the major malaria vectors in the Afro-tropical region, are ongoing a process of ecological diversification and adaptive lineage splitting, which is affecting malaria transmission and vector control strategies in West Africa. These two incipient species are defined on the basis of single nucleotide differences in the IGS and ITS regions of multicopy rDNA located on the X-chromosome. A number of PCR and PCR-RFLP approaches based on form-specific SNPs in the IGS region are used for M and S identification. Moreover, a PCR-method to detect the M-specific insertion of a short interspersed transposable element (SINE200 has recently been introduced as an alternative identification approach. However, a large-scale comparative analysis of four widely used PCR or PCR-RFLP genotyping methods for M and S identification was never carried out to evaluate whether they could be used interchangeably, as commonly assumed. Results The genotyping of more than 400 A. gambiae specimens from nine African countries, and the sequencing of the IGS-amplicon of 115 of them, highlighted discrepancies among results obtained by the different approaches due to different kinds of biases, which may result in an overestimation of MS putative hybrids, as follows: i incorrect match of M and S specific primers used in the allele specific-PCR approach; ii presence of polymorphisms in the recognition sequence of restriction enzymes used in the PCR-RFLP approaches; iii incomplete cleavage during the restriction reactions; iv presence of different copy numbers of M and S-specific IGS-arrays in single individuals in areas of secondary contact between the two forms. Conclusions The results reveal that the PCR and PCR-RFLP approaches most commonly utilized to identify A. gambiae M and S forms are not fully interchangeable as usually assumed, and highlight limits of the actual definition of the two molecular forms, which might

  16. Sharing of antigens between Plasmodium falciparum and Anopheles albimanus Antígenos compartidos entre Plasmodium falciparum y Anopheles albimanus

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    Albina Wide

    2006-12-01

    Full Text Available The presence of common antigens between Plasmodium falciparum and Anopheles albimanus was demonstrated. Different groups of rabbits were immunized with: crude extract from female An. albimanus (EAaF, red blood cells infected with Plasmodium falciparum (EPfs, and the SPf66 synthetic malaria vaccine. The rabbit's polyclonal antibodies were evaluated by ELISA, Multiple Antigen Blot Assay (MABA, and immunoblotting. All extracts were immunogenic in rabbits according to these three techniques, when they were evaluated against the homologous antigens. Ten molecules were identified in female mosquitoes and also in P. falciparum antigens by the autologous sera. The electrophoretic pattern by SDS-PAGE was different for the three antigens evaluated. Cross-reactions between An. albimanus and P. falciparum were found by ELISA, MABA, and immunoblotting. Anti-P. falciparum and anti-SPf66 antibodies recognized ten and five components in the EAaF crude extract, respectively. Likewise, immune sera against female An. albimanus identified four molecules in the P. falciparum extract antigen. As far as we know, this is the first work that demonstrates shared antigens between anophelines and malaria parasites. This finding could be useful for diagnosis, vaccines, and the study of physiology of the immune response to malaria.Epítopes de antígenos compartidos entre Plasmodium falciparum y Anopheles albimanus fueron identificados. Diferentes grupos de conejos fueron inmunizados con: extracto crudo de mosquito hembra de An. albimanus (EAaH, glóbulos rojos infectados con P. falciparum (EPfs y la vacuna antimalárica sintética SPf66. Los anticuerpos policlonales producidos en conejos fueron evaluados por ELISA, inmunoensayo simultáneo de múltiples antígenos (MABA e Immunoblotting. Todos los extractos resultaron inmunogénicos cuando se evaluaron por ELISA, MABA e Immunoblotting. Diez moléculas fueron identificadas en los mosquitos hembras y diez en los antígenos de

  17. Present habitat suitability for Anopheles atroparvus (Diptera, Culicidae and its coincidence with former malaria areas in mainland Portugal

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    César Capinha

    2009-05-01

    Full Text Available Malaria was a major health problem in the first half of the 20th Century in mainland Portugal. Nowadays, although the disease is no longer endemic, there is still the risk of future endemic infections due to the continuous occurrence of imported cases and the possibility of transmission in the country by Anopheles atroparvus Van Thiel, 1927. Since vector abundance constitute one of the foremost factors in malaria transmission, we have created several habitat suitability models to describe this vector species’ current distribution. Three different correlative models; namely (i a multilayer perceptron artificial neural network (MLP-ANN; (ii binary logistic regression (BLR; and (iii Mahalanobis distance were used to combine the species records with a set of five environmental predictors. Kappa coefficient values from k-fold cross-validation records showed that binary logistic regression produced the best predictions, while the other two models also produced acceptable results. Therefore, in order to reduce uncertainty, the three suitability models were combined. The resulting model identified high suitability for An. atroparvus in the majority of the country with exception of the northern and central coastal areas. Malaria distribution during the last endemic period in the country was also compared with the combined suitability model, and a high degree of spatial agreement was obtained (kappa = 0.62. It was concluded that habitat suitability for malaria vectors can constitute valuable information on the assessment of several spatial attributes of the disease. In addition, the results suggest that the spatial distribution of An. atroparvus in the country remains very similar to the one known about seven decades ago.

  18. Genomic and evolutionary analyses of Tango transposons in Aedes aegypti, Anopheles gambiae and other mosquito species.

    Science.gov (United States)

    Coy, M R; Tu, Z

    2007-08-01

    Tango is a transposon of the Tc1 family and was originally discovered in the African malaria mosquito, Anopheles gambiae. Here we report a systematic analysis of the genome sequence of the yellow fever mosquito, Aedes aegypti, which uncovered three distinct Tango transposons. We name the only An. gambiae Tango transposon AgTango1 and the three Ae. aegypti Tango elements AeTango1-3. Like AgTango1, AeTango1 and AeTango2 elements both have members that retain characteristics of autonomous elements such as intact open reading frames and terminal inverted repeats (TIRs). AeTango3 is a degenerate transposon with no full-length members. All full-length Tango transposons contain subterminal direct repeats within their TIRs. AgTango1 and AeTango1-3 form a single clade among other Tc1 transposons. Within this clade, AgTango1 and AeTango1 are closely related and share approximately 80% identity at the amino acid level, which exceeds the level of similarity of the majority of host genes in the two species. A survey of Tango in other mosquito species was carried out using degenerate PCR. Tango was isolated and sequenced in all members of the An. gambiae species complex, Aedes albopictus and Ochlerotatus atropalpus. Oc. atropalpus contains a rich diversity of Tango elements, while Tango elements in Ae. albopictus and the An. gambiae species complex all belong to Tango1. No Tango was detected in Culex pipiens quinquefasciatus, Anopheles stephensi, Anopheles dirus, Anopheles farauti or Anopheles albimanus using degenerate PCR. Bioinformatic searches of the Cx. p. quinquefasciatus (~10 x coverage) and An. stephensi (0.33 x coverage) databases also failed to uncover any Tango elements. Although other evolutionary scenarios cannot be ruled out, there are indications that Tango1 underwent horizontal transfer among divergent mosquito species.

  19. DINAMIKA POPULASI Anopheles Aconitus KAITANYA DENGAN PREVALENSI MALARIA DI KECAMATAN CINEAM, TASIKMALAYA

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    Amrul Munif

    2012-10-01

    Full Text Available A study on the correlation of population dynamik An. aconitus with malaria prevalence was conducted in Cineam sub-district, Tasikmalaya district, West Java from August 1998 to March 2000. In 1996, outbreaks of malaria did not only occur in the coastal areas but was also spread throughout the more remote areas. Malaria transmission can be detected by the presence of infectious gametocyte dan non-immune individuals, as well as by looking at environmental factors (rainfall and also the density of vector population. The intensity of malaria transmission and the degree of malaria prevalence are affected greatly by the last factor.   The intensity is also determined by the degree of contact between the person and the vector. An. aconitus have been suspected as malaria vector in Cineam sub-district, Tasikmalaya district. The observation of the bionomics wich one component of mosquitoes and its relationship with malaria prevalence as well as the determination of Anopheles spp. as malaria vectors in endemic areas should be given attention as an effort in preventing malaria outbreaks. The high density of vector mosquitoes is partly caused by their high diversity. Determination of the prevalence value is based on the Slide positifrate (SPR that was obtained from analyzing blood samples of the  population. There was an examination on passive case detection (PCD, active case detection  (ACD, and mass blood survey (MBS of the population beforehand. Methods used in surveying dan catching the vector mosquitoes include using humans as bait both inside and outside the house, using light trap, by resting, and also spraying. The longitudinal survey methods were used. Each catched mosquito was identified by looking at its morphological features.The transmission of malaria was found to occur all year round with the highest peak found in August 1998 (SPR= 4.9%, but then declined drastically in May (SPR=2.46% and July 1999 (SPR= 2.4% The occurrence of human biting

  20. Vector capacity of Anopheles sinensis in malaria outbreak areas of central China

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    Pan Jia-Yun

    2012-07-01

    Full Text Available Abstract Background Both falciparum and vivax malaria were historically prevalent in China with high incidence. With the control efforts, the annual incidence in the whole country has reduced to 0.0001% except in some areas in the southern borders after 2000. Despite this, the re-emergence or outbreak of malaria was unavoidable in central China during 2005–2007. In order to understand the role of the vector in the transmission of malaria during the outbreak period, the vector capacity of An. sinensis in Huanghuai valley of central China was investigated. Findings The study was undertaken in two sites, namely Huaiyuan county of Anhui province and Yongcheng county of Henan province. In each county, malaria cases were recorded for recent years, and transmission risk factors for each study village including anti-mosquito facilities and total number of livestock were recorded by visiting each household in the study sites. The specimens of mosquitoes were collected in two villages, and population density and species in each study site were recorded after the identification of different species, and the blood-fed mosquitoes were tested by ring precipitation test. Finally, various indicators were calculated to estimate vector capacity or dynamics, including mosquito biting rate (MBR, human blood index (HBI, and the parous rates (M. Finally, the vector capacity, as an important indicator of malaria transmission to predict the potential recurrence of malaria, was estimated and compared in each study site. About 93.0% of 80 households in Huaiyuan and 89.3% of 192 households in Yongcheng had anti-mosquito facilities. No cattle or pigs were found, only less than 10 sheep were found in each study village. A total of 94 and 107 Anopheles spp. mosquitos were captured in two study sites, respectively, and all of An. sinensis were morphologically identified. It was found that mosquito blood-feeding peak was between 9:00 pm and 12:00 pm. Man biting rate of

  1. Insecticide resistance in Anopheles gambiae: data from the first year of a multi-country study highlight the extent of the problem

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    Sagnon N'Falé

    2009-12-01

    Full Text Available Abstract Background Insecticide resistance in malaria vectors is a growing concern in many countries which requires immediate attention because of the limited chemical arsenal available for vector control. The current extent and distribution of this resistance in many parts of the continent is unknown and yet such information is essential for the planning of effective malaria control interventions. Methods In 2008, a network was established, with financial support from WHO/TDR, to investigate the extent of insecticide resistance in malaria vectors in five African countries. Here, the results of bioassays on Anopheles gambiae sensu lato from two rounds of monitoring from 12 sentinel sites in three of the partner countries are reported. Results Resistance is very heterogeneous even over relatively small distances. Furthermore, in some sites, large differences in mortality rates were observed during the course of the malaria transmission season. Using WHO diagnostic doses, all populations from Burkina Faso and Chad and two of the four populations from Sudan were classified as resistant to permethrin and/or deltamethrin. Very high frequencies of DDT resistance were found in urban areas in Burkina Faso and Sudan and in a cotton-growing district in Chad. In areas where both An. gambiae s.s. and Anopheles arabiensis were present, resistance was found in both species, although generally at a higher frequency in An gambiae s.s. Anopheles gambiae s.l. remains largely susceptible to the organophosphate fenitrothion and the carbamate bendiocarb in the majority of the sentinel sites with the exception of two sites in Burkina Faso. In the cotton-growing region of Soumousso in Burkina Faso, the vector population is resistant to all four classes of insecticide available for malaria control. Conclusions Possible factors influencing the frequency of resistant individuals observed in the sentinel sites are discussed. The results of this study highlight the

  2. The cytochrome P450 CYP6P4 is responsible for the high pyrethroid resistance in knockdown resistance-free Anopheles arabiensis

    Science.gov (United States)

    Ibrahim, Sulaiman S.; Riveron, Jacob M.; Stott, Robert; Irving, Helen; Wondji, Charles S.

    2016-01-01

    Pyrethroid insecticides are the front line vector control tools used in bed nets to reduce malaria transmission and its burden. However, resistance in major vectors such as Anopheles arabiensis is posing a serious challenge to the success of malaria control. Herein, we elucidated the molecular and biochemical basis of pyrethroid resistance in a knockdown resistance-free Anopheles arabiensis population from Chad, Central Africa. Using heterologous expression of P450s in Escherichia coli coupled with metabolism assays we established that the over-expressed P450 CYP6P4, located in the major pyrethroid resistance (rp1) quantitative trait locus (QTL), is responsible for resistance to Type I and Type II pyrethroid insecticides, with the exception of deltamethrin, in correlation with field resistance profile. However, CYP6P4 exhibited no metabolic activity towards non-pyrethroid insecticides, including DDT, bendiocarb, propoxur and malathion. Combining fluorescent probes inhibition assays with molecular docking simulation, we established that CYP6P4 can bind deltamethrin but cannot metabolise it. This is possibly due to steric hindrance because of the large vdW radius of bromine atoms of the dihalovinyl group of deltamethrin which docks into the heme catalytic centre. The establishment of CYP6P4 as a partial pyrethroid resistance gene explained the observed field resistance to permethrin, and its inability to metabolise deltamethrin probably explained the high mortality from deltamethrin exposure in the field populations of this Sudano-Sahelian An. arabiensis. These findings describe the heterogeneity in resistance towards insecticides, even from the same class, highlighting the need to thoroughly understand the molecular basis of resistance before implementing resistance management/control tools. PMID:26548743

  3. The cytochrome P450 CYP6P4 is responsible for the high pyrethroid resistance in knockdown resistance-free Anopheles arabiensis.

    Science.gov (United States)

    Ibrahim, Sulaiman S; Riveron, Jacob M; Stott, Robert; Irving, Helen; Wondji, Charles S

    2016-01-01

    Pyrethroid insecticides are the front line vector control tools used in bed nets to reduce malaria transmission and its burden. However, resistance in major vectors such as Anopheles arabiensis is posing a serious challenge to the success of malaria control. Herein, we elucidated the molecular and biochemical basis of pyrethroid resistance in a knockdown resistance-free Anopheles arabiensis population from Chad, Central Africa. Using heterologous expression of P450s in Escherichia coli coupled with metabolism assays we established that the over-expressed P450 CYP6P4, located in the major pyrethroid resistance (rp1) quantitative trait locus (QTL), is responsible for resistance to Type I and Type II pyrethroid insecticides, with the exception of deltamethrin, in correlation with field resistance profile. However, CYP6P4 exhibited no metabolic activity towards non-pyrethroid insecticides, including DDT, bendiocarb, propoxur and malathion. Combining fluorescent probes inhibition assays with molecular docking simulation, we established that CYP6P4 can bind deltamethrin but cannot metabolise it. This is possibly due to steric hindrance because of the large vdW radius of bromine atoms of the dihalovinyl group of deltamethrin which docks into the heme catalytic centre. The establishment of CYP6P4 as a partial pyrethroid resistance gene explained the observed field resistance to permethrin, and its inability to metabolise deltamethrin probably explained the high mortality from deltamethrin exposure in the field populations of this Sudano-Sahelian An. arabiensis. These findings describe the heterogeneity in resistance towards insecticides, even from the same class, highlighting the need to thoroughly understand the molecular basis of resistance before implementing resistance management/control tools.

  4. BIONOMIK NYAMUK MANSONIA DAN ANOPHELES DI DESA KARYA MAKMUR, KABUPATEN OKU TIMUR

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    Yanelza Supranelfy

    2016-09-01

    Full Text Available Abstract Lymphatic filariasis is still become the health problem in Indonesia, the disease almost found inthe entire area with fairly high level endemicity. Karya Makmur Village, Madang Suku III District, EastOgan Komering Ulu Regency, South Sumatera Province in 2007 has micofilariae rate of 1,05% based fromblood survey. The aims of the research is to identify vector and the breeding habitat. This research has beenconducted in Karya Makmur Village from May to November 2011. This type of research is noninterventionstudy with spot survey research design. Mosquitoes collection using human landing andresting collection methods, while mosquito larvae were collected from breeding sites. This research found14 species of Mansonia and Anopheles were collected and the species were Mansonia uniformis, Ma.annulata, Ma. indiana, Ma. dives, Ma. bonneae, Ma. annulifera, Anopheles nigerrimus , An. annularis, An.maculatus, An. letifer, An. vagus, An. barbumbrosus, An. barbirostris and An. tesselatus. Mansoniauniformis and Anopheles nigerrimus was confirmed as filariasis vector but none containing microfilariae.Breeding habitat of Anopheles have water temperature 280C — 300C and pH 7 with vegetation (grass andEichhornia crassipes / water hyacinth and predator (Oreochromis niloticus / nile tilapia and Aplocheiluspanchax / fish head lead. Thus the community are expected to behave positively, especially avoidmosquito bites and manipulate the environment that potentially as mosquito larvae breeding habitat.Keywords: Mansonia, Anopheles, filariasis, Karya Makmur Village AbstrakFilariasis limfatik masih merupakan masalah kesehatandi Indonesia, penyebaran penyakit ini hampirdi seluruh wilayah dan dibeberapa daerah dengan tingkatendemic yang cukup tinggi. Desa Karya Makmur, Kecamatan Madang SukuIII, Kabupaten Ogan KomeringUlu Timur, Propinsi Sumatera Selatan pada tahun2007, mikrofilariarate sebesar1,05% berdasarkansurvey darah jari. Tujuan penelitian untuk mengetahui

  5. Long-lasting insecticidal nets are synergistic with mass drug administration for interruption of lymphatic filariasis transmission in Nigeria.

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    Abel Eigege

    Full Text Available In central Nigeria Anopheles mosquitoes transmit malaria and lymphatic filariasis (LF. The strategy used for interrupting LF transmission in this area is annual mass drug administration (MDA with albendazole and ivermectin, but after 8 years of MDA, entomological evaluations in sentinel villages showed continued low-grade mosquito infection rates of 0.32%. After long-lasting insecticidal net (LLIN distribution by the national malaria program in late 2010, however, we were no longer able to detect infected vectors over a 24-month period. This is evidence that LLINs are synergistic with MDA in interrupting LF transmission.

  6. Impact of insecticide-treated bed nets on malaria transmission indices on the south coast of Kenya

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    Mutuku Francis M

    2011-12-01

    Full Text Available Abstract Background Besides significantly reducing malaria vector densities, prolonged usage of bed nets has been linked to decline of Anopheles gambiae s.s. relative to Anopheles arabiensis, changes in host feeding preference of malaria vectors, and behavioural shifts to exophagy (outdoor biting for the two important malaria vectors in Africa, An. gambiae s.l. and Anopheles funestus. In southern coastal Kenya, bed net use was negligible in 1997-1998 when Anopheles funestus and An. gambiae s.s. were the primary malaria vectors, with An. arabiensis and Anopheles merus playing a secondary role. Since 2001, bed net use has increased progressively and reached high levels by 2009-2010 with corresponding decline in malaria transmission. Methods To evaluate the impact of the substantial increase in household bed net use within this area on vector density, vector composition, and human-vector contact, indoor and outdoor resting mosquitoes were collected in the same region during 2009-2010 using pyrethrum spray catches and clay pots for indoor and outdoor collections respectively. Information on bed net use per sleeping spaces and factors influencing mosquito density were determined in the same houses using Poisson regression analysis. Species distribution was determined, and number of mosquitoes per house, human-biting rates (HBR, and entomological inoculation rate (EIR were compared to those reported for the same area during 1997-1998, when bed net coverage had been minimal. Results Compared to 1997-1998, a significant decline in the relative proportion of An. gambiae s.s. among collected mosquitoes was noted, coupled with a proportionate increase of An. arabiensis. Following > 5 years of 60-86% coverage with bed nets, the density, human biting rate and EIR of indoor resting mosquitoes were reduced by more than 92% for An. funestus and by 75% for An. gambiae s.l. In addition, the host feeding choice of both vectors shifted more toward non

  7. Field evaluation of lambda-cyhalothrin (ICON 10 CS indoor residual spraying against Anopheles culicifacies in India

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    K. Raghavendra, S.K. Ghosh, Alex Eapen, S.N. Tiwari, T.S. Satyanarayan, John Ravindran, U. Sreehari & A.P. Dash

    2011-03-01

    Full Text Available Background & objectives: Field trials of lambda-cyhalothrin 10 CS (ICON 10 CS in indoor residual spraying(IRS with 25 mg a.i./m2 against Anopheles culicifacies was undertaken vs malathion IRS (25% WP–2 g a.i./m2 in Tumkur district, Karnataka; vs deltamethrin IRS (2.5% WP–20 mg a.i./m2 in Dharmapuri district; andvs lambda-cyhalothrin (10 WP–25 mg a.i./m2 in Ramanathapuram district, Tamil Nadu, India.Methods: Spray operations in the experimental villages were done by the National Institute of Malaria Research(NIMR and in the control villages by the respective State Health Department staff. Persistence of efficacy ofinsecticide sprayed in villages was assessed by contact bioassays against vector mosquitoes. Entomologicalindicators such as per structure density, parity rates of vector mosquitoes and sporozoite rates were measuredin all the three study areas using standard procedures. Mass blood surveys and active fever case detectionswere carried out in experimental and control villages to study the impact of IRS on malaria transmission.Results: Persistence of effectiveness of ICON 10 CS was observed up to 2–3 months in all the three studyareas. ICON 10 CS was found effective at par with or better than the insecticides used in the national programmein reducing the mosquito densities and in interrupting malaria transmission in the study villages. Vectordensity, parity rates and malaria cases considerably reduced in the ICON 10 CS-sprayed villages.Conclusion: Field trials at three sites have established that ICON 10 CS formulation was relatively moreeffective than malathion 25% WP, deltamethrin 2.5% WP and lambda-cyhalothrin 10% WP in some evaluationparameters like indoor resting mosquitoes, parity rates in vector mosquitoes and persistence of effectiveness.It can be used for IRS for malaria vector control with two rounds of spray at an interval of 3 months forcurtailing the malaria transmission and an additional round is recommended in

  8. Identification and characterization of the expression profile of microRNAs in Anopheles anthropophagus

    OpenAIRE

    Liu, Wenquan; Huang, Huicong; Xing, Cuicui; Li, Chunxiang; TAN, FENG; Liang, Shaohui

    2014-01-01

    Background Anopheles anthropophagus, one of the most important mosquito-borne disease vectors in Asia, mainly takes blood meals from humans and transmits both malaria and filariae. MicroRNAs (miRNAs) are small non-coding RNAs, and play a critical role in many cellular processes, including development, differentiation, apoptosis and innate immunity. Methods We investigated the global miRNA expression profile of male and female adults of A. anthropophagus using illumina Hiseq2000 sequencing com...

  9. Blood feeding induces hemocyte proliferation and activation in the African malaria mosquito, Anopheles gambiae Giles

    OpenAIRE

    Bryant, William B.; Michel, Kristin

    2014-01-01

    Malaria is a global public health problem, especially in sub-Saharan Africa, where the mosquito Anopheles gambiae Giles serves as the major vector for the protozoan Plasmodium falciparum Welch. One determinant of malaria vector competence is the mosquito's immune system. Hemocytes are a critical component as they produce soluble immune factors that either support or prevent malaria parasite development. However, despite their importance in vector competence, understanding of their basic biolo...

  10. Metabolic and Target-Site Mechanisms Combine to Confer Strong DDT Resistance in Anopheles gambiae

    OpenAIRE

    2014-01-01

    The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms) and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible ...

  11. The Brazilian Malaria Vector Anopheles (Kerteszia) Cruzii: Life Stages and Biology (Diptera: Culicidae)

    Science.gov (United States)

    1991-11-01

    Mosquitos no litoral paranaense. I - Idade fisioldgica de no Parque National da Serra dos Orgaos, Anopheles cruzii (Diptera, Culicidae). Arq. Estado do...no Parque National da Peryassii, A.G. 1908. OS culicideos do Brazil. Serra dos Grgaos, Estado do Rio de Janeiro, Inst. de Manguinhos, Rio de Janeiro...Kerteszia no litoral Guimar%es, A.E. and V.N.M. Victoria. 1986. do estado de Santa Catarina. Rev. Bras. Mosquitos no Parque National da Serra dos

  12. Robust and regulatory expression of defensin A gene driven by vitellogenin promoter in transgenic Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    CHEN XiaoGuang; ZHANG YaJing; ZHENG XueLi; WANG ChunMei

    2007-01-01

    The use of genetically modified mosquitoes to reduce or replace field populations is a new strategy to control mosquito-borne diseases. The precondition of the implementation of this strategy is the ability to manipulate the genome of mosquitoes and to induce specific expression of the effector molecules driven by a suitable promoter. The objective of this study is to evaluate the expression of defensin A gene of Anopheles sinensis under the control of a vitellogenin promoter in transgenic Anopheles stephensi. The regulatory region of Anopheles gambiae vitellogenin was cloned and subcloned into transfer vector pSLFa consisting of an expression cassette with defensin A coding sequence. Then, the expression cassette was transferred into transformation vector pBac[3xP3-DsRedafm] using Asc I digestion. The recombinant plasmid DNA of pBac[3xP3DsRed-AgVgT2-DefA] and helper plasmid DNA of phsp-pBac were micro-injected into embryos of An. stephensi. The positive transgenic mosquitoes were screened by observing specific red fluorescence in the eyes of G1 larvae. Southern blot analysis showed that a single-copy transgene integrated into the genome of An. stephensi. RT-PCR analysis showed that the defensin A gene expressed specifically in fat bodies of female mosquitoes after a blood meal. Interestingly, the mRNA of defensin A is more stable compared with that of the endogenous vitellogenin gene. After multiple blood meals, the expression of defensin A appeared as a reducible and non-cycling type, a crucial feature for its anti-pathogen effect. From data above, we concluded that the regulatory function of the Vg promoter and the expression of defensin A gene were relatively conserved in different species of anopheles mosquitoes. These molecules could be used as candidates in the development of genetically modified mosquitoes.

  13. SNP discovery and molecular evolution in Anopheles gambiae, with special emphasis on innate immune system

    OpenAIRE

    Koutsos Anastasios; Morlais Isabelle; Simard Frédéric; Krishnakumar Sujatha; Cohuet Anna; Fontenille Didier; Mindrinos Michael; Kafatos Fotis C

    2008-01-01

    Abstract Background Anopheles innate immunity affects Plasmodium development and is a potential target of innovative malaria control strategies. The extent and distribution of nucleotide diversity in immunity genes might provide insights into the evolutionary forces that condition pathogen-vector interactions. The discovery of polymorphisms is an essential step towards association studies of susceptibility to infection. Results We sequenced coding fragments of 72 immune related genes in natur...

  14. Evidence for Population-Specific Positive Selection on Immune Genes of Anopheles gambiae

    OpenAIRE

    Crawford, Jacob E; Bischoff, Emmanuel; Garnier, Thierry; Gneme, Awa; Eiglmeier, Karin; Holm, Inge; Michelle M Riehle; Guelbeogo, Wamdaogo M.; Sagnon, N’Fale; Brian P Lazzaro; Vernick, Kenneth D

    2012-01-01

    Host-pathogen interactions can be powerful drivers of adaptive evolution, shaping the patterns of molecular variation at the genes involved. In this study, we sequenced alleles from 28 immune-related loci in wild samples of multiple genetic subpopulations of the African malaria mosquito Anopheles gambiae, obtaining unprecedented sample sizes and providing the first opportunity to contrast patterns of molecular evolution at immune-related loci in the recently discovered GOUNDRY population to t...

  15. High Genetic Differentiation between the M and S Molecular Forms of Anopheles gambiae in Africa

    OpenAIRE

    Caroline Esnault; Matthieu Boulesteix; Jean Bernard Duchemin; Koffi, Alphonsine A; Fabrice Chandre; Roch Dabiré; Vincent Robert; Frédéric Simard; Frédéric Tripet; Donnelly, Martin J.; Didier Fontenille; Christian Biémont

    2008-01-01

    BACKGROUND: Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status. METHODOLOGY/PRINCI...

  16. The mode of action of spatial repellents and their impact on vectorial capacity of Anopheles gambiae sensu stricto.

    Directory of Open Access Journals (Sweden)

    Sheila B Ogoma

    Full Text Available Malaria vector control relies on toxicity of insecticides used in long lasting insecticide treated nets and indoor residual spraying. This is despite evidence that sub-lethal insecticides reduce human-vector contact and malaria transmission. The impact of sub-lethal insecticides on host seeking and blood feeding of mosquitoes was measured. Taxis boxes distinguished between repellency and attraction inhibition of mosquitoes by measuring response of mosquitoes towards or away from Transfluthrin coils and humans. Protective effective distance of coils and long-term effects on blood feeding were measured in the semi-field tunnel and in a Peet Grady chamber. Laboratory reared pyrethroid susceptible Anopheles gambiae sensu stricto mosquitoes were used. In the taxis boxes, a higher proportion of mosquitoes (67%-82% were activated and flew towards the human in the presence of Transfluthrin coils. Coils did not hinder attraction of mosquitoes to the human. In the semi-field Tunnel, coils placed 0.3 m from the human reduced feeding by 86% (95% CI [0.66; 0.95] when used as a "bubble" compared to 65% (95% CI [0.51; 0.76] when used as a "point source". Mosquitoes exposed to coils inside a Peet Grady chamber were delayed from feeding normally for 12 hours but there was no effect on free flying and caged mosquitoes exposed in the semi-field tunnel. These findings indicate that airborne pyrethroids minimize human-vector contact through reduced and delayed blood feeding. This information is useful for the development of target product profiles of spatial repellent products that can be used to complement mainstream malaria vector control tools.

  17. Evaluation of the effectiveness of malaria vector control measures in urban settings of Dakar by a specific anopheles salivary biomarker.

    Directory of Open Access Journals (Sweden)

    Papa Makhtar Drame

    Full Text Available Standard entomological methods for evaluating the impact of vector control lack sensitivity in low-malaria-risk areas. The detection of human IgG specific to Anopheles gSG6-P1 salivary antigen reflects a direct measure of human-vector contact. This study aimed to assess the effectiveness of a range of vector control measures (VCMs in urban settings by using this biomarker approach. The study was conducted from October to December 2008 on 2,774 residents of 45 districts of urban Dakar. IgG responses to gSG6-P1 and the use of malaria VCMs highly varied between districts. At the district level, specific IgG levels significantly increased with age and decreased with season and with VCM use. The use of insecticide-treated nets, by drastically reducing specific IgG levels, was by far the most efficient VCM regardless of age, season or exposure level to mosquito bites. The use of spray bombs was also associated with a significant reduction of specific IgG levels, whereas the use of mosquito coils or electric fans/air conditioning did not show a significant effect. Human IgG response to gSG6-P1 as biomarker of vector exposure represents a reliable alternative for accurately assessing the effectiveness of malaria VCM in low-malaria-risk areas. This biomarker tool could be especially relevant for malaria control monitoring and surveillance programmes in low-exposure/low-transmission settings.

  18. Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

    Science.gov (United States)

    Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

    2015-01-01

    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

  19. The Mode of Action of Spatial Repellents and Their Impact on Vectorial Capacity of Anopheles gambiae sensu stricto

    Science.gov (United States)

    Ogoma, Sheila B.; Ngonyani, Hassan; Simfukwe, Emmanuel T.; Mseka, Antony; Moore, Jason; Maia, Marta F.; Moore, Sarah J.; Lorenz, Lena M.

    2014-01-01

    Malaria vector control relies on toxicity of insecticides used in long lasting insecticide treated nets and indoor residual spraying. This is despite evidence that sub–lethal insecticides reduce human–vector contact and malaria transmission. The impact of sub–lethal insecticides on host seeking and blood feeding of mosquitoes was measured. Taxis boxes distinguished between repellency and attraction inhibition of mosquitoes by measuring response of mosquitoes towards or away from Transfluthrin coils and humans. Protective effective distance of coils and long-term effects on blood feeding were measured in the semi–field tunnel and in a Peet Grady chamber. Laboratory reared pyrethroid susceptible Anopheles gambiae sensu stricto mosquitoes were used. In the taxis boxes, a higher proportion of mosquitoes (67%–82%) were activated and flew towards the human in the presence of Transfluthrin coils. Coils did not hinder attraction of mosquitoes to the human. In the semi–field Tunnel, coils placed 0.3 m from the human reduced feeding by 86% (95% CI [0.66; 0.95]) when used as a “bubble” compared to 65% (95% CI [0.51; 0.76]) when used as a “point source”. Mosquitoes exposed to coils inside a Peet Grady chamber were delayed from feeding normally for 12 hours but there was no effect on free flying and caged mosquitoes exposed in the semi–field tunnel. These findings indicate that airborne pyrethroids minimize human–vector contact through reduced and delayed blood feeding. This information is useful for the development of target product profiles of spatial repellent products that can be used to complement mainstream malaria vector control tools. PMID:25485850

  20. Susceptibility of Anopheles stephensi to Plasmodium gallinaceum: a trait of the mosquito, the parasite, and the environment.

    Directory of Open Access Journals (Sweden)

    Jen C C Hume

    Full Text Available BACKGROUND: Vector susceptibility to Plasmodium infection is treated primarily as a vector trait, although it is a composite trait expressing the joint occurrence of the parasite and the vector with genetic contributions of both. A comprehensive approach to assess the specific contribution of genetic and environmental variation on "vector susceptibility" is lacking. Here we developed and implemented a simple scheme to assess the specific contributions of the vector, the parasite, and the environment to "vector susceptibility." To the best of our knowledge this is the first study that employs such an approach. METHODOLOGY/PRINCIPAL FINDINGS: We conducted selection experiments on the vector (while holding the parasite "constant" and on the parasite (while holding the vector "constant" to estimate the genetic contributions of the mosquito and the parasite to the susceptibility of Anopheles stephensi to Plasmodium gallinaceum. We separately estimated the realized heritability of (i susceptibility to parasite infection by the mosquito vector and (ii parasite compatibility (transmissibility with the vector while controlling the other. The heritabilities of vector and the parasite were higher for the prevalence, i.e., fraction of infected mosquitoes, than the corresponding heritabilities of parasite load, i.e., the number of oocysts per mosquito. CONCLUSIONS: The vector's genetics (heritability comprised 67% of "vector susceptibility" measured by the prevalence of mosquitoes infected with P. gallinaceum oocysts, whereas the specific contribution of parasite genetics (heritability to this trait was only 5%. Our parasite source might possess minimal genetic diversity, which could explain its low heritability (and the high value of the vector. Notably, the environment contributed 28%. These estimates are relevant only to the particular system under study, but this experimental design could be useful for other parasite-host systems. The prospects and

  1. A resting box for outdoor sampling of adult Anopheles arabiensis in rice irrigation schemes of lower Moshi, northern Tanzania

    Directory of Open Access Journals (Sweden)

    Msangi Shandala

    2009-04-01

    Full Text Available Abstract Background Malaria vector sampling is the best method for understanding the vector dynamics and infectivity; thus, disease transmission seasonality can be established. There is a need to protecting humans involved in the sampling of disease vectors during surveillance or in control programmes. In this study, human landing catch, two cow odour baited resting boxes and an unbaited resting box were evaluated as vector sampling tools in an area with a high proportion of Anopheles arabiensis, as the major malaria vector. Methods Three resting boxes were evaluated against human landing catch. Two were baited with cow odour, while the third was unbaited. The inner parts of the boxes were covered with black cloth materials. Experiments were arranged in latin-square design. Boxes were set in the evening and left undisturbed; mosquitoes were collected at 06:00 am the next morning, while human landing catch was done overnight. Results A total of 9,558 An. arabiensis mosquitoes were collected. 17.5% (N = 1668 were collected in resting box baited with cow body odour, 42.5% (N = 4060 in resting box baited with cow urine, 15.1% (N = 1444 in unbaited resting box and 24.9% (N = 2386 were collected by human landing catch technique. In analysis, the house positions had no effect on the density of mosquitoes caught (DF = 3, F = 0.753, P = 0.387; the sampling technique had significant impact on the caught mosquitoes densities (DF = 3, F 37. 944, P Conclusion Odour-baited resting boxes have shown the possibility of replacing the existing traditional method (human landing catch for sampling malaria vectors in areas with a high proportion of An. arabiensis as malaria vectors. Further evaluations of fermented urine and longevity of the urine odour still need to be investigated.

  2. Larvicidal activity of silver nanoparticles synthesized using Plumeria rubra plant latex against Aedes aegypti and Anopheles stephensi.

    Science.gov (United States)

    Patil, Chandrashekhar D; Patil, Satish V; Borase, Hemant P; Salunke, Bipinchandra K; Salunkhe, Rahul B

    2012-05-01

    In the present study activity of silver nanoparticles (AgNPs) synthesized using Plumeria rubra plant latex against second and fourth larval instar of Aedes aegypti and Anopheles stephensi was determined. Range of concentrations of synthesized AgNps (10, 5, 2.5, 1.25, 0.625, 0.3125 ppm) and aqueous crude latex (1,000, 500, 250, 125, 62.50, 31.25 ppm) were tested against larvae of A. aegypti and A. Stephensi. The synthesized AgNps from P. rubra latex were highly toxic than crude latex extract in both mosquito species. The LC(50) values for second and fourth larval instars after 24 h of crude latex exposure were 1.49, 1.82 ppm against A. aegypti and 1.10, 1.74 ppm against A. stephensi respectively. These figures were 181.67, 287.49 ppm against A. aegypti and 143.69, 170.58 ppm against A. stephensi respectively for crude latex extract. The mortality rates were positively correlated with the concentration of AgNPs. The characterization studies of synthesized AgNPs by UV-Vis spectrophotometry, transmission electron microscopy (TEM), Particle size analysis (PSA) and zeta potential confirmed the spherical shape and size (32-200 nm) of silver nanoparticles along with stability. Toxicity studies carried out against non-target fish species Poecilia reticulata, the most common organism in the habitats of A. aegypti and A. stephensi showed no toxicity at LC(50) and LC(90) doses of the AgNPs. This is the first report on mosquito larvicidal activity of latex synthesized nanoparticles.

  3. Synergy in efficacy of fungal entomopathogens and permethrin against West African insecticide-resistant Anopheles gambiae mosquitoes.

    Directory of Open Access Journals (Sweden)

    Marit Farenhorst

    Full Text Available BACKGROUND: Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the compatibility of the pyrethroid insecticide permethrin and two mosquito-pathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, against a laboratory colony and field population of West African insecticide-resistant Anopheles gambiae s.s. mosquitoes. METHODOLOGY/FINDINGS: A range of fungus-insecticide combinations was used to test effects of timing and sequence of exposure. Both the laboratory-reared and field-collected mosquitoes were highly resistant to permethrin but susceptible to B. bassiana and M. anisopliae infection, inducing 100% mortality within nine days. Combinations of insecticide and fungus showed synergistic effects on mosquito survival. Fungal infection increased permethrin-induced mortality rates in wild An. gambiae s.s. mosquitoes and reciprocally, exposure to permethrin increased subsequent fungal-induced mortality rates in both colonies. Simultaneous co-exposure induced the highest mortality; up to 70.3+/-2% for a combined Beauveria and permethrin exposure within a time range of one gonotrophic cycle (4 days. CONCLUSIONS/SIGNIFICANCE: Combining fungi and permethrin induced a higher impact on mosquito survival than the use of these control agents alone. The observed synergism in efficacy shows the potential for integrated fungus-insecticide control measures to dramatically reduce malaria transmission and enable control at more moderate levels of coverage even in areas where insecticide resistance has rendered pyrethroids essentially ineffective.

  4. Plasmodium falciparum malaria challenge by the bite of aseptic Anopheles stephensi mosquitoes: results of a randomized infectivity trial.

    Directory of Open Access Journals (Sweden)

    Kirsten E Lyke

    Full Text Available BACKGROUND: Experimental infection of malaria-naïve volunteers by the bite of Plasmodium falciparum-infected mosquitoes is a preferred means to test the protective effect of malaria vaccines and drugs. The standard model relies on the bite of five infected mosquitoes to induce malaria. We examined the efficacy of malaria transmission using mosquitoes raised aseptically in compliance with current Good Manufacturing Practices (cGMPs. METHODS AND FINDINGS: Eighteen adults aged 18-40 years were randomized to receive 1, 3 or 5 bites of Anopheles stephensi mosquitoes infected with the chloroquine-sensitive NF54 strain of P. falciparum. Seventeen participants developed malaria; fourteen occurring on Day 11. The mean prepatent period was 10.9 days (9-12 days. The geometric mean parasitemia was 15.7 parasites/µL (range: 4-70 by microscopy. Polymerase chain reaction (PCR detected parasites 3.1 (range: 0-4 days prior to microscopy. The geometric mean sporozoite load was 16,753 sporozoites per infected mosquito (range: 1,000-57,500. A 1-bite participant withdrew from the study on Day 13 post-challenge and was PCR and smear negative. CONCLUSIONS: The use of aseptic, cGMP-compliant P. falciparum-infected mosquitoes is safe, is associated with a precise prepatent period compared to the standard model and appears more efficient than the standard approach, as it led to infection in 100% (6/6 of volunteers exposed to three mosquito bites and 83% (5/6 of volunteers exposed to one mosquito bite. TRIAL REGISTRATION: ClinicalTrials.gov NCT00744133.

  5. Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

    Directory of Open Access Journals (Sweden)

    Read Andrew F

    2009-04-01

    Full Text Available Abstract Background Temperature is a critical determinant of the development of malaria parasites in mosquitoes, and hence the geographic distribution of malaria risk, but little is known about the thermal preferences of Anopheles. A number of other insects modify their thermal behaviour in response to infection. These alterations can be beneficial for the insect or for the infectious agent. Given current interest in developing fungal biopesticides for control of mosquitoes, Anopheles stephensi were examined to test whether mosquitoes showed thermally-mediated behaviour in response to infection with fungal entomopathogens and the rodent malaria, Plasmodium yoelii. Methods Over two experiments, groups of An. stephensi were infected with one of three entomopathogenic fungi, and/or P. yoelii. Infected and uninfected mosquitoes were released on to a thermal gradient (14 – 38°C for "snapshot" assessments of thermal preference during the first five days post-infection. Mosquito survival was monitored for eight days and, where appropriate, oocyst prevalence and intensity was assessed. Results and conclusion Both infected and uninfected An. stephensi showed a non-random distribution on the gradient, indicating some capacity to behaviourally thermoregulate. However, chosen resting temperatures were not altered by any of the infections. There is thus no evidence that thermally-mediated behaviours play a role in determining malaria prevalence or that they will influence the performance of fungal biopesticides against adult Anopheles.

  6. Larvicidal and pupicidal activity of spinosad against the malarial vector Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Kolanthasamy Prabhu; Kadarkarai Murugan; Arjunan Nareshkumar; Subramanian Bragadeeswaran

    2011-01-01

    Objective:To investigate the larvicidal and pupicidal activity of spinosad againstAnopheles stephensi Listen.Methods: Spinosad from the actinomycete,Saccharopolyspora spinosa was tested againstAnopheles stephensi at different concentrations (0.01, 0.02, 0.04, 0.06 and0.08ppm.), and against first to fourth instar larvae and pupae.Results: The larval mortality ranged from36.1±1.7 in (0.01 ppm) to 79.3±1.8 (0.08 ppm) the first instar larva. The LC50andLC90values of first, second, third and fourth instar larva were0.001, 0.031, 0.034, 0.036and0.0113, 0.102, 0.111, 0.113, respectively. The pupal mortality ranged from33.0±2.0 (0.01 ppm) to 80.0±0.9 (0.08 ppm). The LC50 andLC90values were0.028 and 0.1020, respectively. The reduction percentage ofAnopheles larvae was82.7%, 91.4% and96.0% after 24, 48, 72 hours, respectively, while more than80% reduction was observed after3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial. It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.

  7. Reticulate Speciation and Barriers to Introgression in the Anopheles gambiae Species Complex.

    Science.gov (United States)

    Crawford, Jacob E; Riehle, Michelle M; Guelbeogo, Wamdaogo M; Gneme, Awa; Sagnon, N'Fale; Vernick, Kenneth D; Nielsen, Rasmus; Lazzaro, Brian P

    2015-11-28

    Speciation as a process remains a central focus of evolutionary biology, but our understanding of the genomic architecture and prevalence of speciation in the face of gene flow remains incomplete. The Anopheles gambiae species complex of malaria mosquitoes is a radiation of ecologically diverse taxa. This complex is well-suited for testing for evidence of a speciation continuum and genomic barriers to introgression because its members exhibit partially overlapping geographic distributions as well as varying levels of divergence and reproductive isolation. We sequenced 20 genomes from wild A. gambiae s.s., Anopheles coluzzii, Anopheles arabiensis, and compared these with 12 genomes from the "GOUNDRY" subgroup of A. gambiae s.l. Amidst a backdrop of strong reproductive isolation, we find strong evidence for a speciation continuum with introgression of autosomal chromosomal regions among species and subgroups. The X chromosome, however, is strongly differentiated among all taxa, pointing to a disproportionately large effect of X chromosome genes in driving speciation among anophelines. Strikingly, we find that autosomal introgression has occurred from contemporary hybridization between A. gambiae and A. arabiensis despite strong divergence (∼5× higher than autosomal divergence) and isolation on the X chromosome. In addition to the X, we find strong evidence that lowly recombining autosomal regions, especially pericentromeric regions, serve as barriers to introgression secondarily to the X. We show that speciation with gene flow results in genomic mosaicism of divergence and introgression. Such a reticulate gene pool connecting vector taxa across the speciation continuum has important implications for malaria control efforts.

  8. A viral over-expression system for the major malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Suzuki, Yasutsugu; Niu, Guodong; Hughes, Grant L; Rasgon, Jason L

    2014-05-30

    Understanding pathogen/mosquito interactions is essential for developing novel strategies to control mosquito-borne diseases. Technical advances in reverse-genetics, such as RNA interference (RNAi), have facilitated elucidation of components of the mosquito immune system that are antagonistic to pathogen development, and host proteins essential for parasite development. Forward genetic approaches, however, are limited to generation of transgenic insects, and while powerful, mosquito transgenesis is a resource- and time-intensive technique that is not broadly available to most laboratories. The ability to easily "over-express" genes would enhance molecular studies in vector biology and expedite elucidation of pathogen-refractory genes without the need to make transgenic insects. We developed and characterized an efficient Anopheles gambiae densovirus (AgDNV) over-expression system for the major malaria vector Anopheles gambiae. High-levels of gene expression were detected at 3 days post-infection and increased over time, suggesting this is an effective system for gene induction. Strong expression was observed in the fat body and ovaries. We validated multiple short promoters for gene induction studies. Finally, we developed a polycistronic system to simultaneously express multiple genes of interest. This AgDNV-based toolset allows for consistent transduction of genes of interest and will be a powerful molecular tool for research in Anopheles gambiae mosquitoes.

  9. No evidence for lymphatic filariasis transmission in big cities affected by conflict related rural-urban migration in Sierra Leone and Liberia.

    Directory of Open Access Journals (Sweden)

    Dziedzom K de Souza

    2014-02-01

    Full Text Available BACKGROUND: In West Africa, the principal vectors of lymphatic filariasis (LF are Anopheles species with Culex species playing only a minor role in transmission, if any. Being a predominantly rural disease, the question remains whether conflict-related migration of rural populations into urban areas would be sufficient for active transmission of the parasite. METHODOLOGY/PRINCIPAL FINDINGS: We examined LF transmission in urban areas in post-conflict Sierra Leone and Liberia that experienced significant rural-urban migration. Mosquitoes from Freetown and Monrovia, were analyzed for infection with Wuchereria bancrofti. We also undertook a transmission assessment survey (TAS in Bo and Pujehun districts in Sierra Leone. The majority of the mosquitoes collected were Culex species, while Anopheles species were present in low numbers. The mosquitoes were analyzed in pools, with a maximum of 20 mosquitoes per pool. In both countries, a total of 1731 An. gambiae and 14342 Culex were analyzed for W. bancrofti, using the PCR. Two pools of Culex mosquitoes and 1 pool of An. gambiae were found infected from one community in Freetown. Pool screening analysis indicated a maximum likelihood of infection of 0.004 (95% CI of 0.00012-0.021 and 0.015 (95% CI of 0.0018-0.052 for the An. gambiae and Culex respectively. The results indicate that An. gambiae is present in low numbers, with a microfilaria prevalence breaking threshold value not sufficient to maintain transmission. The results of the TAS in Bo and Pujehun also indicated an antigen prevalence of 0.19% and 0.67% in children, respectively. This is well below the recommended 2% level for stopping MDA in Anopheles transmission areas, according to WHO guidelines. CONCLUSIONS: We found no evidence for active transmission of LF in cities, where internally displaced persons from rural areas lived for many years during the more than 10 years conflict in Sierra Leone and Liberia.

  10. Observations on sporozoite detection in naturally infected sibling species of the Anopheles culicifacies complex and variant of Anopheles stephensi in India

    Indian Academy of Sciences (India)

    Susanta Kumar Ghosh; Satyanarayan Tiwari; Kamaraju Raghavendra; Tiruchinapalli Sundaraj; Aditya Prasad Dash

    2008-09-01

    Sporozoites were detected in naturally infected sibling species of the primary rural vector Anopheles culicifacies complex in two primary health centres (PHCs) and a variant of the urban vector Anopheles stephensi in Mangalore city, Karnataka, south India while carrying out malaria outbreak investigations from 1998–2006. Sibling species of An. culicifacies were identified based on the banding patterns on ovarian polytene chromosomes, and variants of An. stephensi were identified based on the number of ridges on the egg floats. Sporozoites were detected in the salivary glands by the dissection method. Of the total 334 salivary glands of An. culicifacies dissected, 17 (5.08%) were found to be positive for sporozoites. Of the 17 positive samples, 11 were suitable for sibling species analysis; 10 were species A (an efficient vector) and 1 was species B (a poor vector). Out of 46 An. stephensi dissected, one was sporozoite positive and belonged to the type form (an efficient vector). In malaria epidemiology this observation is useful for planning an effective vector control programme, because each sibling species/variant differs in host specificity, susceptibility to malarial parasites, breeding habitats and response to insecticides.

  11. The practical importance of permanent and semipermanent habitats for controlling aquatic stages of Anopheles gambiae sensu lato mosquitoes: operational observations from a rural town in western Kenya

    NARCIS (Netherlands)

    Fillinger, U.; Sonye, G.; Killeen, G.F.; Knols, B.G.J.; Becker, N.

    2004-01-01

    Control of aquatic-stage Anopheles is one of the oldest and most historically successful interventions to prevent malaria, but it has seen little application in Africa. Consequently, the ecology of immature afrotropical Anopheles has received insufficient attention. We therefore examined the populat

  12. Combining indoor residual spraying with chlorfenapyr and long-lasting insecticidal bed nets for improved control of pyrethroid-resistant Anopheles gambiae: an experimental hut trial in Benin

    Directory of Open Access Journals (Sweden)

    Ngufor Corine

    2011-11-01

    Full Text Available Abstract Background Neither indoor residual spraying (IRS nor long-lasting insecticidal nets (LLINs are able to fully interrupt transmission in holoendemic Africa as single interventions. The combining of IRS and LLINs presents an opportunity for improved control and management of pyrethroid resistance through the simultaneous presentation of unrelated insecticides. Method Chlorfenapyr IRS and a pyrethroid-impregnated polyester LLIN (WHO approved were tested separately and together in experimental huts in southern Benin against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus. The bed nets were deliberately holed with either six or 80 holes to examine the effect of increasing wear and tear on protectiveness. Anopheles gambiae were genotyped for the kdr gene to assess the combination's potential to prevent the selection of pyrethroid resistance. Results The frequency of kdr was 84%. The overall mortality rates of An. gambiae were 37% and 49% with the six-hole and 80-hole LLINs, respectively, and reached 57% with chlorfenapyr IRS. Overall mortality rates were significantly higher with the combination treatments (82-83% than with the LLIN or IRS individual treatments. Blood feeding (mosquito biting rates were lowest with the 6-hole LLIN (12%, intermediate with the 80-hole LLIN (32% and highest with untreated nets (56% with the 6-hole and 54% with the 80-hole nets. Blood feeding (biting rates and repellency of mosquitoes with the combination of LLIN and chlorfenapyr IRS showed significant improvement compared to the IRS treatment but did not differ from the LLIN treatments indicating that the LLINs were the primary agents of personal protection. The combination killed significantly higher proportions of Cx. quinquefasciatus (51%, 41% than the LLIN (15%, 13% or IRS (32% treatments. Conclusion The chlorfenapyr IRS component was largely responsible for controlling pyrethroid-resistant mosquitoes and the LLIN component was largely

  13. Survey of Transmission Cost Allocation Methodologies for Regional Transmission Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Fink, S.; Porter, K.; Mudd, C.; Rogers, J.

    2011-02-01

    The report presents transmission cost allocation methodologies for reliability transmission projects, generation interconnection, and economic transmission projects for all Regional Transmission Organizations.

  14. Larvicidal, oviposition, and ovicidal effects of Artemisia annua (Asterales: Asteraceae) against Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Cheah, Shao-Xiong; Tay, Jia-Wei; Chan, Lai-Keng; Jaal, Zairi

    2013-09-01

    This study focuses on the larvicidal, oviposition, and ovicidal effects of a crude extract of Artemisia annua against Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus. Dried cells of Artemisia annua from cell suspension cultures were extracted using hexane. The extract showed moderate larvicidal effects against mosquitoes. At 24-h post treatment, the LC50 values for Anopheles sinensis, Aedes aegypti, and Culex quinquefasciatus were recorded as 244.55, 276.14, and 374.99 ppm, respectively. The percentage mortality of larvae was directly proportional to the tested concentration. Anopheles sinensis was found to be the most susceptible species, whereas Culex quinquefasciatus was the most tolerant to the Artemisia annua extract. The results indicated that the Artemisia annua extract showed concentration-dependent oviposition deterrent activity and had a strong deterrent effect. At 500 ppm, the percentage effective repellency was more than 85% compared with the control group for all the species, with oviposition activity index values of -0.94, -0.95, and -0.78 for Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus, respectively. In the ovicidal assay, the percentage hatchability of eggs after treatment with 500 ppm of Artemisia annua extract was significantly lower than the control, with values of 48.84 ± 4.08, 38.42 ± 3.67, and 79.35 ± 2.09% for Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus, respectively. Artemisia annua was found to be more effective against Aedes aegypti and Anopheles sinensis compared with Culex quinquefasciatus. This study indicated that crude extract of A. annua could be a potential alternative for use in vector management programs.

  15. Targeting the X chromosome during spermatogenesis induces Y chromosome transmission ratio distortion and early dominant embryo lethality in Anopheles gambiae.

    OpenAIRE

    Nikolai Windbichler; Philippos Aris Papathanos; Andrea Crisanti

    2008-01-01

    Author Summary A. gambiae mosquitoes are the main vectors of human malaria. The inadequacy of existing control measures for these mosquitoes has prompted research into methods for genetic control. We have genetically engineered A. gambiae mosquitoes to express, during spermatozoa development, an enzyme that selectively cuts a DNA sequence present only on a family of essential genes located on the X chromosome. We found that in heterozygous male mosquitoes, this genetic modification induced co...

  16. A climate distribution model of malaria transmission in Sudan.

    Science.gov (United States)

    Musa, Mohammed I; Shohaimi, Shamarina; Hashim, Nor R; Krishnarajah, Isthrinayagy

    2012-11-01

    Malaria remains a major health problem in Sudan. With a population exceeding 39 million, there are around 7.5 million cases and 35,000 deaths every year. The predicted distribution of malaria derived from climate factors such as maximum and minimum temperatures, rainfall and relative humidity was compared with the actual number of malaria cases in Sudan for the period 2004 to 2010. The predictive calculations were done by fuzzy logic suitability (FLS) applied to the numerical distribution of malaria transmission based on the life cycle characteristics of the Anopheles mosquito accounting for the impact of climate factors on malaria transmission. This information is visualized as a series of maps (presented in video format) using a geographical information systems (GIS) approach. The climate factors were found to be suitable for malaria transmission in the period of May to October, whereas the actual case rates of malaria were high from June to November indicating a positive correlation. While comparisons between the prediction model for June and the case rate model for July did not show a high degree of association (18%), the results later in the year were better, reaching the highest level (55%) for October prediction and November case rate.

  17. Gal4-based enhancer-trapping in the malaria mosquito Anopheles stephensi.

    Science.gov (United States)

    O'Brochta, David A; Pilitt, Kristina L; Harrell, Robert A; Aluvihare, Channa; Alford, Robert T

    2012-11-01

    Transposon-based forward and reverse genetic technologies will contribute greatly to ongoing efforts to study mosquito functional genomics. A piggyBac transposon-based enhancer-trap system was developed that functions efficiently in the human malaria vector, Anopheles stephensi. The system consists of six transgenic lines of Anopheles stephensi, each with a single piggyBac-Gal4 element in a unique genomic location; six lines with a single piggyBac-UAStdTomato element; and two lines, each with a single Minos element containing the piggyBac-transposase gene under the regulatory control of the hsp70 promoter from Drosophila melanogaster. Enhancer detection depended upon the efficient remobilization of piggyBac-Gal4 transposons, which contain the yeast transcription factor gene Gal4 under the regulatory control of a basal promoter. Gal4 expression was detected through the expression of the fluorescent protein gene tdTomato under the regulatory control of a promoter with Gal4-binding UAS elements. From five genetic screens for larval- and adult-specific enhancers, 314 progeny were recovered from 24,250 total progeny (1.3%) with unique patterns of tdTomato expression arising from the influence of an enhancer. The frequency of piggyBac remobilization and enhancer detection was 2.5- to 3-fold higher in female germ lines compared with male germ lines. A small collection of enhancer-trap lines are described in which Gal4 expression occurred in adult female salivary glands, midgut, and fat body, either singly or in combination. These three tissues play critical roles during the infection of Anopheles stephensi by malaria-causing Plasmodium parasites. This system and the lines generated using it will be valuable resources to ongoing mosquito functional genomics efforts.

  18. Mitochondrial genome sequences reveal deep divergences among Anopheles punctulatus sibling species in Papua New Guinea

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    Logue Kyle

    2013-02-01

    Full Text Available Abstract Background Members of the Anopheles punctulatus group (AP group are the primary vectors of human malaria in Papua New Guinea. The AP group includes 13 sibling species, most of them morphologically indistinguishable. Understanding why only certain species are able to transmit malaria requires a better comprehension of their evolutionary history. In particular, understanding relationships and divergence times among Anopheles species may enable assessing how malaria-related traits (e.g. blood feeding behaviours, vector competence have evolved. Methods DNA sequences of 14 mitochondrial (mt genomes from five AP sibling species and two species of the Anopheles dirus complex of Southeast Asia were sequenced. DNA sequences from all concatenated protein coding genes (10,770 bp were then analysed using a Bayesian approach to reconstruct phylogenetic relationships and date the divergence of the AP sibling species. Results Phylogenetic reconstruction using the concatenated DNA sequence of all mitochondrial protein coding genes indicates that the ancestors of the AP group arrived in Papua New Guinea 25 to 54 million years ago and rapidly diverged to form the current sibling species. Conclusion Through evaluation of newly described mt genome sequences, this study has revealed a divergence among members of the AP group in Papua New Guinea that would significantly predate the arrival of humans in this region, 50 thousand years ago. The divergence observed among the mtDNA sequences studied here may have resulted from reproductive isolation during historical changes in sea-level through glacial minima and maxima. This leads to a hypothesis that the AP sibling species have evolved independently for potentially thousands of generations. This suggests that the evolution of many phenotypes, such as insecticide resistance will arise independently in each of the AP sibling species studied here.

  19. Effect of ivermectin on the larvae of Anopheles gambiae and Culex quinquefasciatus

    DEFF Research Database (Denmark)

    Derua, Yahya A.; Malongo, Bernard B.; Simonsen, Paul E.

    2016-01-01

    Background: Ivermectin is used extensively globally for treatment of helminthic and ectoparasitic infections in animals and humans. The effect of excreted ivermectin on non-target organisms in aquatic and terrestrial environments has been increasingly reported. Due to its low water solubility...... and adsorption to sediments, the ivermectin exposure-risk to aquatic organisms dwelling in different strata of water bodies varies. This study assessed the survival of larvae of Anopheles gambiae Giles and Culex quinquefasciatus Say, when exposed to low concentrations of ivermectin under laboratory conditions...

  20. Small-scale field evaluation of the monomolecular surface film 'Arosurf MSF' against Anopheles arabiensis Patton.

    Science.gov (United States)

    Karanja, D M; Githeko, A K; Vulule, J M

    1994-04-01

    A field trial was conducted to test the insecticidal action of the monolayer surface film 'Arosurf MSF' applied by knapsack sprayers, against larvae and pupae of Anopheles arabiensis Patton in a rice irrigation scheme in Western Kenya. Larval and pupal densities and the number of emerging adults were determined by dipping and emergence cages respectively. Application of the monolayer by knapsack sprayers provided good coverage. There were high daily mortalities of the fourth instar larvae, with no adult emergence from 'Arosurf MSF' treated plots compared to lower fourth instar mortalities and continuous adult emergence from untreated control plots, indicating the potential of the monolayer for control of An. arabiensis mosquitoes in rice fields.

  1. Insecticidal activity of the essential oil of Thymus transcaspicus against Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Leila Dargahi; Kamal Razavi-Azarkhiavi; Mohammad Ramezani; Mohammad Reza Abaee; Javad Behravan

    2014-01-01

    Objective:To investigate the insecticidal activity of the essential oil of Thymus transcaspicus (T. transcaspicus) against Anopheles stephensi (An. stephensi). Methods:An. stephensi were exposed to 31, 63, 125 and 250 µg/L of essential oil of T. transcaspicus for 24 h. Results:The most toxicity was observed at 250 µg/L of essential oil with the LC50 values of 134.1 µg/L after 24 h. Conclusions:The essential oil of T. transcaspicus exhibited strong insecticidal activity against An. stephensi which can be attributed to its constituent especially carvacrol and thymol phenols.

  2. A survey of adult anophelines in French Guiana: enhanced descriptions of species distribution and biting responses.

    Science.gov (United States)

    Dusfour, Isabelle; Carinci, Romuald; Issaly, Jean; Gaborit, Pascal; Girod, Romain

    2013-12-01

    In French Guiana, Anopheles darlingi is considered the main malaria vector. However, several reports have hypothesized the implication of other anopheline species in malaria transmission for the territory. Data on the ecology of these other potential vectors is rare or even unexplored in French Guiana. The aim of this study was to describe the biting habits of several anopheline species in multiple localities in French Guiana. Six sampling sites yielded 1,083 anopheline adults. Results indicated the presence of An. darlingi in all study locations and it was the only species to be collected inside villages. Other anophelines collected included An. aquasalis, An. braziliensis, An. intermedius, An. mediopunctatus, An. nuneztovari, An. oswaldoi, and An. triannulatus, all of which were associated with open areas and forests. The environment and time, at which biting behavior was recorded, varied for each species. It was noted that An. oswaldoi showed a daytime rhythm in open areas. This study is the first to report on the biting habits of a range of anophelines in French Guiana that may play a role in malaria transmission. This information is vital to fully describe the risk of malaria transmission and thereby design appropriate vector control measures and malaria prevention programs.

  3. Fauna anofélica da cidade de Belém, Pará, Brasil: dados atuais e retrospectivos Anophelines in Belém, Pará, Brazil: current and retrospective data

    Directory of Open Access Journals (Sweden)

    Ana de Nazaré Martins da Silva

    2006-08-01

    Full Text Available Relato de coletas de anofelinos realizadas em Belém, Pará, Brasil, de 1995 a 2004, comparando os dados obtidos com os de levantamentos anteriores, feitos a partir da década de 1930. Nesses, vinte espécies haviam sido identificadas: Anopheles albitarsis s.l., An. aquasalis, An. argyritarsis, An. braziliensis, An. darlingi, An. eiseni, An. evansae, An. galvaoi, An. intermedius, An. kompi, An. mediopunctatus, An. nimbus, An. nuneztovari, An. oswaldoi, An. peryassui, An. punctimacula, An. shannoni, An. strodei, An. thomasi e An. triannulatus. Sete (An. argyritarsis, An. eiseni, An. galvaoi, An. kompi, An. nimbus, An. punctimacula e An. thomasi não são agora registradas. A permanência de tantas outras espécies provavelmente decorre da preservação de áreas de mata no âmbito urbano. Duas delas são consideradas de importância vetorial (An. darlingi e An. aquasalis. Esta última continua sendo a de maior densidade nas coletas (46,26% dos adultos e 99,21% das larvas e é a única registrada em todos os distritos administrativos. Existe, portanto, risco potencial de transmissão de malária em todo o município.We present the results of anopheline captures in Belém, Pará, Brazil, from 1995-2004, and a comparison with captures from 1930-1999. In the earlier period, 20 species were identified: Anopheles albitarsis s.l., An. aquasalis, An. argyritarsis, An. braziliensis, An. darlingi, An. eiseni, An. evansae, An. galvaoi, An. intermedius, An. kompi, An. mediopunctatus, An. nimbus, An. nuneztovari, An. oswaldoi, An. peryassui, An. punctimacula, An. shannoni, An. strodei, An. thomasi, and An. triannulatus. Seven of these species were not found in 1995-2004 (An. argyritarsis, An. eiseni, An. galvaoi, An. kompi, An. nimbus, An. punctimacula, and An. thomasi. The persistence of so many species is probably due to the local preservation of forest areas. Two species are of vectorial importance (An. darlingi and An. aquasalis. An. aquasalis is still

  4. An extra-domiciliary method of delivering entomopathogenic fungus, Metharizium anisopliae IP 46 for controlling adult populations of the malaria vector, Anopheles arabiensis

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    Mnyone Ladslaus L

    2010-03-01

    Full Text Available Abstract Fungal biopesticides have the potential to significantly reduce densities of malaria vectors as well as associated malaria transmission. In previous field trials, entomopathogenic fungus was delivered from within human dwellings, where its efficacy was limited by low infection rates of target mosquitoes, high costs of spraying fungus inside houses, and potential public health concerns associated with introducing fungal conidia inside houses. Here we have demonstrated that Metarhizium anisopliae IP 46, delivered within an extra-domiciliary odor-baited station (OBS, can infect and slowly-kill a high proportion of the wild adult malaria vector, Anopheles arabiensis which entered and exited the OBS. This study, carried out in rural Tanzania, showed that by using a concentration of 3.9 × 1010 conidia/m2, more than 95% of mosquitoes that flew in and out of the OBS died within 14 days post-exposure. At least 86% infection of mosquito cadavers was recorded with a significant reduction in the probability of daily survival of exposed An. arabiensis in both treatments tested: low quantity of conidia (eave baffles plus one cotton panel; HR = 2.65, P P

  5. rDNA-ITS2 based species-diagnostic polymerase chain reaction assay for identification of sibling species of Anopheles fluviatilis in Iran.

    Science.gov (United States)

    Dezfouli, S R Naddaf; Oshaghi, M A; Vatandoost, H; Assmar, M

    2003-01-01

    A species-specific polymerase chain reaction (PCR) assay using primers already designed, based on differences in the nucleotides of the second internal transcribed spacer (ITS2), was used to identify the species composition of the Anopheles fluviatilis complex in Iran. All the amplified DNA samples obtained from specimens collected from different areas using different collection methods yielded to a fragment of 450 bp size, a PCR product corresponding to the species denoted as Y. Some 21 ITS2 region of Iranian specimens were sequenced and compared with the already published sequence data of species Y from India. The sequence data of the Iranian specimens were 100% identical to that of the Indian specimens, and hence confirmed the PCR assay results. Species Y is presumably species T in India, which has no role in the transmission of malaria, whereas mosquitos of An. fluviatilis are known as a secondary vector in Iran. This conflict will remain to be solved by further biological and molecular studies.

  6. Malaria infection of the mosquito Anopheles gambiae activates immune-responsive genes during critical transition stages of the parasite life cycle.

    Science.gov (United States)

    Dimopoulos, G; Seeley, D; Wolf, A; Kafatos, F C

    1998-01-01

    Six gene markers have been used to map the progress of the innate immune response of the mosquito vector, Anopheles gambiae, upon infection by the malaria parasite, Plasmodium berghei. In addition to four previously reported genes, the set of markers included NOS (a nitric oxide synthase gene fragment) and ICHIT (a gene encoding two putative chitin-binding domains separated by a polythreonine-rich mucin region). In the midgut, a robust response occurs at 24 h post-infection, at a time when malaria ookinetes traverse the midgut epithelium, but subsides at later phases of malaria development. In contrast, the salivary glands show no significant response at 24 h, but are activated in a prolonged late phase when sporozoites are released from the midgut into the haemolymph and invade the glands, between 10 and 25 days after blood feeding. Furthermore, the abdomen of the mosquito minus the midgut shows significant activation of immune markers, with complex kinetics that are distinct from those of both midgut and salivary glands. The parasite evidently elicits immune responses in multiple tissues of the mosquito, two of which are epithelia that the parasite must traverse to complete its development. The mechanisms of these responses and their significance for malaria transmission are discussed. PMID:9799221

  7. Plasmodium falciparum infection rates for some Anopheles spp. from Guinea-Bissau, West Africa [v1; ref status: indexed, http://f1000r.es/4in

    Directory of Open Access Journals (Sweden)

    Michelle R. Sanford

    2014-10-01

    Full Text Available Presence of Plasmodium falciparum circumsporozoite protein (CSP was detected by enzyme linked immunosorbent assay (ELISA in a sample of Anopheles gambiae s.s., A. melas and A. pharoensis collected in Guinea-Bissau during October and November 2009. The percentage of P. falciparum infected samples (10.2% overall was comparable to earlier studies from other sites in Guinea-Bissau (9.6-12.4%. The majority of the specimens collected were identified as A. gambiae which had an individual infection rate of 12.6 % across collection sites. A small number of specimens of A. coluzzii, A. coluzzii x A. gambiae hybrids, A. melas and A. pharoensis were collected and had infection rates of 4.3%, 4.1%, 11.1% and 33.3% respectively. Despite being present in low numbers in indoor collections, the exophilic feeding behaviors of A. melas (N=18 and A. pharoensis (N=6 and high infection rates observed in this survey suggest falciparum-malaria transmission potential outside of the protection of bed nets.

  8. Study on Fungal Flora in the Midgut of the Larva and Adult of the Different Populations of the Malaria Vector Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    L Tajedin

    2009-07-01

    Full Text Available Abstract Background: Many microorganisms in midgut of mosquito challenge with their host and also other pathogens pre­sent in midgut. The aim of this study was presence of non-pathogens microorganisms like fungal flora which may be cru­cial on interaction between vectors and pathogens."nMethods: Different populations of Anopheles stephensi were reared in insectary and objected to determine fungal flora in their midguts. The midgut paunch of mosquito adults and larvae as well as breading water and larval food sam­ples transferred on Subaru-dextrose agar, in order to detect the environment fungus."nResults: Although four fungi, Aspergillus, Rhizopus, Geotrichum and Sacharomyces were found in the food and wa­ter, but only Aspiragilus observed in the midgut of larvae. No fungus was found in the midgut of adults. This is the first report on fungal flora in the midgut of the adults and larvae of An. stephensi and possible stadial transmission of fungi from immature stages to adults."nConclusion: The midgut environment of adults is not compatible for survivorship of fungi but the larval midgut may con­tain few fungi as a host or even pathogen.

  9. Dynamics of multiple insecticide resistance in the malaria vector Anopheles gambiae in a rice growing area in South-Western Burkina Faso

    Directory of Open Access Journals (Sweden)

    Ouédraogo Jean-Bosco

    2008-09-01

    Full Text Available Abstract Background Insecticide resistance of the main malaria vector, Anopheles gambiae, has been reported in south-western Burkina Faso, West Africa. Cross-resistance to DDT and pyrethroids was conferred by alterations at site of action in the sodium channel, the Leu-Phe kdr mutation; resistance to organophosphates and carbamates resulted from a single point mutation in the oxyanion hole of the acetylcholinesterase enzyme designed as ace-1R. Methods An entomological survey was carried out during the rainy season of 2005 at Vallée du Kou, a rice growing area in south-western Burkina Faso. At the Vallée du Kou, both insecticide resistance mechanisms have been previously described in the M and S molecular forms of An. gambiae. This survey aimed i to update the temporal dynamics and the circumsporozoite infection rate of the two molecular forms M and S of An. gambiae ii to update the frequency of the Leu-Phe kdr mutation within these forms and finally iii to investigate the occurrence of the ace-1R mutation. Mosquitoes collected by indoor residual collection and by human landing catches were counted and morphologically identified. Species and molecular forms of An. gambiae, ace-1R and Leu-Phe kdr mutations were determined using PCR techniques. The presence of the circumsporozoite protein of Plasmodium falciparum was determined using ELISA. Results Anopheles gambiae populations were dominated by the M form. However the S form occurred in relative important proportion towards the end of the rainy season with a maximum peak in October at 51%. Sporozoite rates were similar in both forms. The frequency of the Leu-Phe kdr mutation in the S form reached a fixation level while it is still spreading in the M form. Furthermore, the ace-1R mutation prevailed predominately in the S form and has just started spreading in the M form. The two mutations occurred concomitantly both in M and S populations. Conclusion These results showed that the Vallée du Kou

  10. Mosquito larvicidal properties of silver nanoparticles synthesized using Heliotropium indicum (Boraginaceae) against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Rajeswary, Mohan; Muthukumaran, Udaiyan

    2014-06-01

    Mosquitoes transmit dreadful diseases to human beings wherein biological control of these vectors using plant-derived molecules would be an alternative to reduce mosquito population. In the present study activity of aqueous leaf extract and silver nanoparticles (AgNPs) synthesized using Helitropium indicum plant leaves against late third instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The range of varying concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg/mL) and aqueous leaf extract (30, 60, 90, 120, and 150 μg/mL) were tested against the larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The synthesized AgNPs from H. indicum were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis, transmission electron microscopy, and histogram. The synthesized AgNPs showed larvicidal effects after 24 h of exposure. Considerable mortality was evident after the treatment of H. indicum for all three important vector mosquitoes. The LC50 and LC90 values of H. indicum aqueous leaf extract appeared to be effective against A. stephensi (LC50, 68.73 μg/mL; LC90, 121.07 μg/mL) followed by A. aegypti (LC50, 72.72 μg/mL; LC90, 126.86 μg/mL) and C. quinquefasciatus (LC50, 78.74 μg/mL; LC90, 134.39 μg/mL). Synthesized AgNPs against the vector mosquitoes of A. stephensi, A. aegypti, and C. quinquefasciatus had the following LC50 and LC90 values: A. stephensi had LC50 and LC90 values of 18.40 and 32.45 μg/mL, A. aegypti had LC50 and LC90 values of 20.10 and 35.97 μg/mL, and C. quinquefasciatus had LC50 and LC90 values of 21.84 and 38.10 μg/mL. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H. indicum and green synthesis of silver nanoparticles have the

  11. A marked seasonality of malaria transmission in two rural sites in eastern Sudan

    DEFF Research Database (Denmark)

    Hamad, Amel A; Nugud, Abd El Hamid D; Arnot, David E;

    2002-01-01

    . The entomological inoculation rate (EIR) was estimated to be around two to three infective bites per person per year, although heterogeneity in the transmission indices of malaria between the two villages was observed. The implications of these patterns of anopheline population dynamics for the epidemiology......The ecology of Anopheles arabiensis and its relationship to malaria transmission was investigated in two villages in eastern Sudan. Seasonal malaria case incidence was compared with the number of vectors detected and with climatic variables. Following the end of the short rainy season in October...... season between February and May, sporadic asymptomatic malaria infections were detected in the two villages. The low endemicity of malaria in the area was reflected by the relatively low total September-December parasite and sporozoite rates (15 and 1.4%, respectively) measured in the villages...

  12. Karakteristik Habitat Larva Anopheles spp. di Desa Sungai Nyamuk, Daerah Endemik Malaria di Kabupaten Nunukan, Kalimantan Utara

    Directory of Open Access Journals (Sweden)

    Sugiarto Sugiarto

    2016-07-01

    Full Text Available A research about Habitat Characteristics of Anopheles spp. larvae was done in Sungai Nyamuk Village, Nunukan District, North Kalimantan Province from August 2010 to January 2012. This research aims to analyse the characteristics of breeding places of Anopheles spp. The larvae taken from various types of habitat with detention and maintained until it was developed into mosquitoes, then later identified. The results showed that there are four types of potential breeding places of Anopheles spp. ie lagoon, ditches, fish ponds and marshes. Anopheles types that are found consist of five species, namely An. vagus, An. subpictus, An. sundaicus, An. indefinitus dan An. peditaeniatus. Types of potential breeding places are dominated by the unused fish pond, with the substrate in the form of mud and water is not flowing, located around settlements surrounded by grasses, shrubs and trees. Breeding places contains of aquatic plants such as grasses and moss. Predators are found in the form of a dragonfly nymph, crustaceans, tadpoles and small fish. Early malaria vector control at the level of the larvae is a critical point of the success of malaria elimination programs in endemic areas.

  13. Extent of digestion affects the success of amplifying human DNA from blood meals of Anopheles gambiae (Diptera: Culicidae)

    NARCIS (Netherlands)

    Mukabana, W.R.; Takken, W.; Seda, P.; Killeen, G.F.; Hawley, W.A.; Knols, B.G.J.

    2002-01-01

    The success of distinguishing blood meal sources of Anopheles gambiae Giles through deoxyribonucleic acid (DNA) profiling was investigated by polymerase chain reaction (PCR) amplification at the TC-11 and VWA human short tandem repeats (STR) loci. Blood meal size and locus had no significant effect

  14. First report of Metarhizium anisopliae IP 46 pathogenicity in adult Anopheles gambiae s.s. and An. arabiensis (Diptera; Culicidae)

    NARCIS (Netherlands)

    Mnyone, L.L.; Russell, T.L.; Lyimo, I.N.; Lwetoijera, D.W.; Kirby, M.J.; Luz, C.

    2009-01-01

    The entomopathogenic fungus Metarhizium anisopliae isolate IP 46, originating from a soil sample collected in 2001 in the Cerrado of Central Brazil, was tested for its ability to reduce the survival of adult male and female Anopheles gambiae s.s. and An. arabiensis mosquitoes. A 6-h exposure to the

  15. Effect of Bacillus sphaericus Neide on Anopheles (Diptera: Culicidae and associated insect fauna in fish ponds in the Amazon

    Directory of Open Access Journals (Sweden)

    Francisco Augusto da Silva Ferreira

    2015-09-01

    Full Text Available ABSTRACTWe analyzed the effects of Bacillus sphaericus on Anopheles larvae and on the associated insect fauna in fish farming ponds. Five breeding sites in the peri-urban area of the city of Manaus, AM, Brazil, were studied. Seven samples were collected from each breeding site and B. sphaericus was applied and reapplied after 15 days. The samples were made at 24 h before application, 24 h post-application and 5 and 15 days post-application. We determined abundance, larval reduction and larval density for Anopheles, and abundance, richness, Shannon diversity index and classified according to the functional trophic groups for associated insect fauna. A total of 904 Anopheles larvae were collected and distributed into five species. Density data and larval reduction demonstrated the rapid effect of the biolarvicide 24 h after application. A total of 4874 associated aquatic insects belonging to six orders and 23 families were collected. Regression analysis of diversity and richness indicated that the application of the biolarvicide had no influence on these indices and thus no effect on the associated insect fauna for a period of 30 days. B. sphaericus was found to be highly effective against the larvae of Anopheles, eliminating the larvae in the first days after application, with no effect on the associated insect fauna present in the fish ponds analyzed.

  16. Odour sensitivity of antennal olfactory cells underlying grooved pegs of Anopheles gambiae s.s. and An. quadriannulatus

    NARCIS (Netherlands)

    van den Broek, IVF; den Otter, CJ

    2000-01-01

    In female mosquitoes of the anthropophilic species Anopheles gambiae Giles s.s. and the zoophilic An. quadriannulatus Theobald single sensillum recordings from grooved pegs were made. In both species, the majority of these sensilla responded to ammonium hydroxide, butylamine and propanoic acid, wher

  17. Man-biting activity of Anopheles (Nyssorhynchus albimanus and An. (Kerteszia neivai (Diptera: Culicidae in the Pacific Lowlands of Colombia

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    Yezid Solarte

    1996-04-01

    Full Text Available The daily man-biting activity of Anopheles (Nyssorhynchus albimanus and An. (Kerteszia neivai was determined in four ecologically distinct settlements of the Naya River, Department of Valle, Colombia. Differences were found among the settlements with respect to the mosquito species present, intradomiciliary and extradomiciliary biting activity and population densities.

  18. Use of Near-Infrared Spectroscopy to Age-Grade and Identify Siblings of Anopheles Gambiae Complex

    Science.gov (United States)

    We used near-infrared spectroscopy (NIRS) to rapidly and non-destructively determine species and age of Anopheles gambiae ss (G3, Mali-NIH, Kisumu, ZANU, and Ifakara strains) and An. arabiensis (Dongola, KGB, and Ifakara strains). We developed NIR calibrations using mosquitoes reared and scanned at ...

  19. A new robust diagnostic polymerase chain reaction for determining the mating status of female Anopheles gambiae mosquitoes

    NARCIS (Netherlands)

    Ng'habi, K.R.; Horton, A.; Knols, B.G.J.; Lanzaro, G.C.

    2007-01-01

    The principal malaria vector in Africa, Anopheles gambiae, contains two pairs of autosomes and one pair of sex chromosomes. The Y chromosome is only associated with males and other Y chromosome¿specific DNA sequences, which are transferred to women during mating. A reliable tool to determine the mat

  20. Differential attractiveness of humans to the African malaria vector Anopheles gambiae Giles - Effects of host characteristics and parasite infection

    NARCIS (Netherlands)

    Mukabana, W.R.

    2002-01-01

    The results of a series of studies designed to understand the principal factors that determine the differential attractiveness of humans to the malaria vector Anopheles gambiae are described in this thesis. Specific

  1. Additional selection for insecticide resistance in urban malaria vectors: DDT resistance in Anopheles arabiensis from Bobo-Dioulasso, Burkina Faso.

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    Christopher M Jones

    Full Text Available In the city of Bobo-Dioulasso in Burkina Faso, Anopheles arabiensis has superseded Anopheles gambiae s.s. as the major malaria vector and the larvae are found in highly polluted habitats normally considered unsuitable for Anopheles mosquitoes. Here we show that An. gambiae s.l. adults emerging from a highly polluted site in the city centre (Dioulassoba have a high prevalence of DDT resistance (percentage mortality after exposure to diagnostic dose=65.8% in the dry season and 70.4% in the rainy season, respectively. An investigation into the mechanisms responsible found an unexpectedly high frequency of the 1014S kdr mutation (allele frequency=0.4, which is found at very low frequencies in An. arabiensis in the surrounding rural areas, and an increase in transcript levels of several detoxification genes, notably from the glutathione transferase and cytochrome P450 gene families. A number of ABC transporter genes were also expressed at elevated levels in the DDT resistant An. arabiensis. Unplanned urbanisation provides numerous breeding grounds for mosquitoes. The finding that Anopheles mosquitoes adapted to these urban breeding sites have a high prevalence of insecticide resistance has important implications for our understanding of the selective forces responsible for the rapid spread of insecticide resistant populations of malaria vectors in Africa.

  2. Larvicidal and repellent activity of Vetiveria zizaniodes (Poaceae) essential oil against the malaria vector Anopheles stephensi (Liston) (Diptera: Culicidae)

    Science.gov (United States)

    Essential oil extracted by steam distillation of Vetiveria zizanioides (L.) Nash (Poaceae) was evaluated for larvicidal and adult repellent activity against the malaria vector Anopheles stephensi (Liston). Median lethal concentrations (LC50) at 24 h post treatment for instars 1-4 were, respectively,...

  3. Toxicity of six plant extracts and two pyridine alkaloids from Ricinus communis against the malaria vector Anopheles gambiae

    Science.gov (United States)

    The African malaria vector, Anopheles gambiae s.s., is known to feed selectively on certain plants for sugar sources. However, the adaptive significance of this behavior especially on how the extracts of such plants impact on the fitness of this vector has not been explored. This study determined th...

  4. An Annotated Checklist of the Anopheles of Thailand (Diptera : Culicidae) (Thai National Scientific Papers, Fauna Series Number 2)

    Science.gov (United States)

    1968-08-01

    Discussion: In most urban and agricultura ! areas of Thailand this is the most abundant Anopheles species encountered. The larvae are found in wide variety of...Entomological Society of America : Washington.) TAUSATHIT. Prasit, TH \\vAR:\\v.\\R\\, Bunyong, CH YL~IVYOO, Skol. and KAMPANARDSAENY~KARA. Chaiyan (1962

  5. BEBERAPA ASPEK BIONOMIK ANOPHELES SP DI KABUPATEN SUMBA TENGAH, PROVINSI NUSA TENGGARA TIMUR

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    Ni Wayan Dewi Adyana

    2012-07-01

    Full Text Available Research Some Aspects of Anopheles sp Bionomik in Central Sumba Regency, Province of East Nusa Tenggara. Committed in the territory Maradesa Health Center. Data were collected by catching adult mosquitoes by using bait People inside and outside the home, a collection of breaks in the wall and at home, continued with larval surveys in all potential breeding places.  The results showed that the biting behavior tends eksofagik found on An. kochi, An. aconitus and An.barbirostris with bite density peaks in An. aconitus (0.6 persons/hour with a biting peak at 20:00 to 21:00. Behavior tends eksofilik break in An. kochi, An. aconitus, An. tesselatus, An. barbirostris, An. vagus, An.flavirostris, An. maculatus and An. indefinitus with the highest density in An.aconitus (0.9 persons/hour at 1:00 a.m. to 2:00 a.m. Anopheles larvae breeding places found in the small hole in the ground, creek, wetland, non-permanent irrigation, water reservoirs in the vegetable garden, ditches, puddles, swamps, springs, with species that are found as An.kochi, An.aconitus, An. tesselatus, An. barbirostris, An. vagus, An. flavirostris, An. maculatus, An. indefinitus and An. annullaris

  6. Unassisted isolated-pair mating of Anopheles gambiae (Diptera: Culicidae) mosquitoes.

    Science.gov (United States)

    Benedict, Mark Q; Rafferty, Cristina S

    2002-11-01

    Female Anopheles mosquitoes usually mate only once, but mating is seldom seen in small containers containing only one female and male. Therefore, matings are often performed among many adults in large cages or by forced copulation. Isolated-pair mating of Anopheles gambiae G3 strain-derived mosquitoes without forced copulation in small vials is described. We observed that the experimental variables eye color and male number were significant factors in the mating frequency. Females mated more frequently when three males were present over only one male. White-eyed females were more likely to be mated than wild-eyed females, but wild males mated more frequently than did white-eyed males. Experiments were also conducted to determine when mating was occurring by using wild-eye-color mosquitoes in isolated pairs. Almost no matings were observed before day 6 rather than the frequencies typically observed after 1-2 d in standard large-cage matings among large numbers of adults.

  7. KOMPOSISI UMUR NYAMUK ANOPHELES sp YANG DIDUGA SEBAGAI VEKTOR DI DAERAH PEGUNUNGAN KECAMATAN LENGKONG, KABUPATEN SUKABUMI

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    Mardiana Mardiana

    2012-11-01

    Full Text Available Anopheles mosquito could be as a disease vector if having age for the growth of malaria parasitein its body. The research was conducted by catching mosquito in nature, namely: using human collection,wall-resting collection, around cattle and using light trap. The caught mosquito was assessing its proportionof parous and longevity, the composition of parous proportion in each species difference, namely: An.aconitvs reached its highest 0.8 and its lowest 0.2. An. barbirostris reached its highest 0.55 and its lowest0.02. The low Index parous indicates that mosquito could not transmit plasmodium to human. The estimation of An.aconitus age reaches the highest of 8.58 days and the lowest 1.23 days. At the age of 8.58 days An.aconitus is able to grow plasmodium in its body. The estimation of An. barbirostris age reachesits highest of 3.49 days and its lowest 1.3 days. An. maculatus age reached its highest age of 2.65 days and its lowest 1.44 days. The mosquito with short age could not be as a malaria vector. It is concluded that An.aconitus was potential as malaria vector. Key words: Anopheles sp, age composition, vector, hill

  8. Ecology of Anopheles dthali Patton in Bandar Abbas District, Hormozgan Province, Southern Iran

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    H Vatandoost

    2007-06-01

    Full Text Available Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re¬gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil¬ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

  9. Ecology of Anopheles dthali Patton in Bandar Abbas District, Hormozgan Province, Southern Iran

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    H Vatandoost

    2007-05-01

    Full Text Available Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re¬gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil¬ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

  10. Indirect evidence that agricultural pesticides select for insecticide resistance in the malaria vector Anopheles gambiae.

    Science.gov (United States)

    Luc, Djogbénou S; Benoit, Assogba; Laurette, Djossou; Michel, Makoutode

    2016-06-01

    We investigated the possible relationship between the agricultural use of insecticides and the emergence of insecticide resistance. Bioassays were conducted using simulated mosquito larval habitats and well known Anopheles gambiae strains. Soil samples were collected from vegetable production areas in Benin, including one site with insecticide use, one site where insecticides had not been used for two months, and a third where insecticides had not been used. Pupation and emergence rates were very low in pyrethroid-susceptible strains when exposed to soil that had been recently exposed to insecticides. Pupation and emergence rates in strains with the kdr mutation alone or both the kdr and Ace-1 mutations were much higher. Overall, strains with the kdr mutation survived at higher rates compared to that without kdr mutation. Although this study is observational, we provide indirect evidence indicating that soils from agricultural areas contain insecticide residues that can play a role in the emergence of insecticide resistance in Anopheles. This aspect should be taken into account to better utilize the insecticide in the context of integrated pest management programs.

  11. Phylogenetics and Srf Analysis of Mitochondrial DNA COII Gene in Anopheles Species (Diptera: Culicidae

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    Monika Sharma

    2011-07-01

    Full Text Available Mitochondrial DNA COII gene was used to study the interspecific variation and molecular analysis among six species of genus Anopheles belonging to subgenus Cellia i.e. An. stephensi, An. culicifacies, An. maculatus, An. subpictus, An. annularis and An. splendidus. The sequence was found to be AT rich with maximum of 75.07% in An. culicifacies. The sequence analysis revealed the number of transversions to be more than transitions which is opposite of the general contention with transitions being more frequent than transversions in mitochondrial genes. However, among the Anopheles species, the maximum number of substitutions was found in An. maculatus. The phylogenetic analysis using the three methods MP, ML and NJ methods was also carried out for which Cx. quinquefasciatus was taken as outgroup. Analysis showed that An. stephensi and An. culicifacies shared a close genetic homology while An. annularis and An. splendidus made another group with identical genetic qualities. To the contrary, An. subpictus and An. maculatus had hypervariable non-homologous genomic qualities. Short tandem as well as nontandem repeats were also studied using SRF (Spectral Repeat Finder programme. The repeats were conserved in all the species except certain polymorphic repeats such as TAT and TTTAT were present in An. stephensi whereas no polymorphic repeats were present in An. subpictus. Identification of repeats is crucial to shed light on the function and structure of proteins, and explain their evolutionary past.

  12. Phytochemistry and larvicidal activity of Eucalyptus camaldulensisagainst malaria vector,Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Sedaghat Mohamad Medhi; SaneiAli Reza; Khnavi Mahnaz; Abai Mohammad Reza; Hadjiakhoondi Abbas; MohtaramiFatemeh; VatandoostHassan

    2010-01-01

    Objective:To determine phytochemistry and larvicidal activity ofEucalyptus camaldulensis againstAnopheles stephensi.Methods:The chemical compositions of the leaf essential oils were analyzed using gas chromatography/mass spectrometry (GC/MS). The larvicidal activity of essential oils and extract of leaf were tested against 4th instar larvae of laboratory-rearedAnopheles stephensi.Results:GC/MS analyses identified the presence of28 compounds corresponding to 99.60%of the total oil. The main constituents in the leaf essential oil were1,8-cineole(69.46%), γ-Terpinene(15.10%), α-Pinene(5.47%)and Globulol(2%). The leaf extract and volatile oil exerted significant larvicidal activity withLC50 values of89.85 and397.75ppm, respectively. Clear dose-response relationships were established with the highest dose of320 ppm essential oil extract resulted almost100% mortality in the population.Conclusions:The larvicidal properties suggest that the essential oil of plant is a potential source of valuable larvicidal compounds against malaria vector and can be used as an alternative to synthetic insecticides.

  13. Exogenous gypsy insulator sequences modulate transgene expression in the malaria vector mosquito, Anopheles stephensi.

    Science.gov (United States)

    Carballar-Lejarazú, Rebeca; Jasinskiene, Nijole; James, Anthony A

    2013-04-30

    Malaria parasites are transmitted to humans by mosquitoes of the genus Anopheles, and these insects are the targets of innovative vector control programs. Proposed approaches include the use of genetic strategies based on transgenic mosquitoes to suppress or modify vector populations. Although substantial advances have been made in engineering resistant mosquito strains, limited efforts have been made in refining mosquito transgene expression, in particular attenuating the effects of insertions sites, which can result in variations in phenotypes and impacts on fitness due to the random integration of transposon constructs. A promising strategy to mitigate position effects is the identification of insulator or boundary DNA elements that could be used to isolate transgenes from the effects of their genomic environment. We applied quantitative approaches that show that exogenous insulator-like DNA derived from the Drosophila melanogaster gypsy retrotransposon can increase and stabilize transgene expression in transposon-mediated random insertions and recombinase-catalyzed, site-specific integrations in the malaria vector mosquito, Anopheles stephensi. These sequences can contribute to precise expression of transgenes in mosquitoes engineered for both basic and applied goals.

  14. Recent reduction in the water level of Lake Victoria has created more habitats for Anopheles funestus

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    Futami Kyoko

    2008-07-01

    Full Text Available Abstract Background The water level of Lake Victoria has fallen more than 1.5 m since 1998, revealing a narrow strip of land along the shore. This study determined whether the recent drop in the water level has created additional breeding grounds for malaria vectors. Methods The recent and past shorelines were estimated using landmarks and a satellite image. The locations of breeding habitats were recorded using a GPS unit during the high and low lake water periods. GIS was used to determine whether the breeding habitats were located on newly emerged land between the new and old shorelines. Results Over half of the breeding habitats existed on newly emerged land. Fewer habitats for the Anopheles gambiae complex were found during the low water level period compared to the high water period. However, more habitats for Anopheles funestus were found during the high water level period, and they were all located on the newly emerged land. Conclusion The recent reduction in water level of Lake Victoria has increased the amount of available habitat for A. funestus. The results suggest that the water drop has substantially affected the population of this malaria vector in the Lake Victoria basin, particularly because the lake has a long shoreline that may harbour many new breeding habitats.

  15. Pyrethroid resistance in southern African Anopheles funestus extends to Likoma Island in Lake Malawi

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    Edwardes M

    2010-12-01

    Full Text Available Abstract Background A mosquito survey was carried out on the island of Likoma in Lake Malawi with a view to collecting baseline data to determine the feasibility of implementing an integrated malaria vector control programme. No vector control interventions are currently being applied on the island apart from the sporadic use of treated and untreated bed nets. Results Large numbers of Anopheles funestus were found resting inside houses. WHO susceptibility tests were carried out on wild caught females and 1-5 day old F-1 female progeny. Wild caught females were tested on deltamethrin (77.8% mortality and bendiocarb (56.4% mortality. Female progeny were tested on deltamethrin (41.4% mortality, permethrin (40.4%, bendiocarb (52.5%, propoxur (7.4%, malathion, fenitrothion, DDT, dieldrin (all 100% and pirimiphos-methyl (98.9%. The malaria parasite rate was 4.9%. A small number of Anopheles arabiensis were also collected. Conclusion This locality is 1,500 km north of the currently known distribution of pyrethroid resistant An. funestus in southern Africa. The susceptibility results mirror those found in southern Mozambique and South African populations, but are markedly different to An. funestus populations in Uganda, indicating that the Malawi resistance has spread from the south.

  16. "Comparison of Midgut Hemagglutination Activity in Three Different Geographical Populations of Anopheles stephensi"

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    HR Basseri

    2004-08-01

    Full Text Available Lectins that agglutinate red blood cells (RBCs were demonstrated in Anopheles stephensi mosquito midgut extracts using human (four groups: A, B, AB and O, RH+ rat, sheep and rabbit blood cells. Only rabbit RBCs showed agglutination reaction against the midgut extracts. Significant differences in hemagglutinin titers and carbohydrate specifity were detected between male and female mosquitoes as well as among three different geographical populations of Anopheles stephensi from south of Iran. Overall agglutinin levels were increased following a blood meal. The highest hemagglintination titers were due to Kazerun population. All hemagglutination assays were versus rabbit RBCS. A significant difference was detected among the number of egg-float ridges. Iranshahr population was different from Bandar-abbas and Kazerun population in egg-float ridges number. Bandr-abbas population was in the intermediate category. Iranshahr population fell between mysoransis and intermediate group and Kazerun population was between intermediate and type form. This study presents the first report on the occurrence of heterogeneous anti Rabbit RBC agglutinins in the midget extracts of the different geographical populations of An.stephensi with the sugar – binding specificities. The sugar- inhibition pattern was different between & within geographical population of An.stephensi.

  17. The effect of parental rearing conditions on offspring life history in Anopheles stephensi

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    Maung Liam

    2007-09-01

    Full Text Available Abstract Background The environmental conditions experienced by parents are increasingly recognized to impact the success of offspring. Little is known on the presence of such parental effects in Anopheles. If present, parental effects could influence mosquito breeding programmes, some malaria control measures and have epidemiological and evolutionary consequences. Methods The presence of parental effects on offspring emergence time, size, survival, blood meal size and fecundity in laboratory reared An. stephensi were tested. Results Parental rearing conditions did not influence the time taken for offspring to emerge, or their size or survival as adults. However, parental effects were influential in determining the fecundity of daughters. Counter-intuitively, daughters of parents reared in low food conditions produced larger egg clutches than daughters of parents reared in high food conditions. Offspring reared in low food conditions took larger blood meals if their parents had also experienced a low food environment. Conclusion So far as we are aware, this is the first evidence of parental effects on progeny in Anopheles.

  18. FAUNA ANOPHELES DI DAERAH PANTAI BEKAS HUTAN MANGROVE KECAMATAN PADANG CERMIN KABUPATEN LAMPUNG SELATAN

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    N. Sushanti Idris-Idram

    2012-09-01

    Full Text Available Intensive mosquito collections were carried out in two villages in subdistrict of Padangcermin during 1992-1993. The method of mosquito collections consisted of night landing on man indoor and outdoor, night resting indoor and outdoor around cattle shelters, light trap in cattle shelters, daytime resting indoor and outdoor, as well as larvae collections to identify anophelines breeding sites. Sixteen anophelines i.e. Anopheles sundaicus, An. subpictus, An. vagus, An. indefinitus, An. nigerrimus, An. peditaeniatus, An. kochi, An. barbirostris, An. bambumbrosus, An. annularis, An. separatus, An. tesselatus, An. aconitus, An. umbrosus, An. leucosphyrus and An. letifer were collected. Among these mosquitos, An. sundaicus was found predominant, followed by An. vagus and An. subpictus. Other species were collected in small numbers. The behavior of Anopheles sundaicus, An. subpictus and An. vagus were exophagic and endophilic. The larvae of An. sundaicus was found only in brackish standing water such as abandoned shrimp ponds, An. subpictus in brackish standing water as well as fresh standing water, while An. vagus was found only in fresh standing water. Breeding sites of An. sundaicus was characterized by pond with floating algae while An. subpictus and An. vagus were not depending on vegetation.

  19. Evaluating the lethal and pre-lethal effects of a range of fungi against adult Anopheles stephensi mosquitoes

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    Blanford Simon

    2012-11-01

    Full Text Available Abstract Background Insecticide resistance is seriously undermining efforts to eliminate malaria. In response, research on alternatives to the use of chemical insecticides against adult mosquito vectors has been increasing. Fungal entomopathogens formulated as biopesticides have received much attention and have shown considerable potential. This research has necessarily focused on relatively few fungal isolates in order to ‘prove concept’. Further, most attention has been paid to examining fungal virulence (lethality and not the other properties of fungal infection that might also contribute to reducing transmission potential. Here, a range of fungal isolates were screened to examine variation in virulence and how this relates to additional pre-lethal reductions in feeding propensity. Methods The Asian malaria vector, Anopheles stephensi was exposed to 17 different isolates of entomopathogenic fungi belonging to species of Beauveria bassiana, Metarhizium anisopliae, Metarhizium acridum and Isaria farinosus. Each isolate was applied to a test substrate at a standard dose rate of 1×109 spores ml-1 and the mosquitoes exposed for six hours. Subsequently the insects were removed to mesh cages where survival was monitored over the next 14 days. During this incubation period the mosquitoes’ propensity to feed was assayed for each isolate by offering a feeding stimulant at the side of the cage and recording the number probing. Results and conclusions Fungal isolates showed a range of virulence to A. stephensi with some causing >80% mortality within 7 days, while others caused little increase in mortality relative to controls over the study period. Similarly, some isolates had a large impact on feeding propensity, causing >50% pre-lethal reductions in feeding rate, whereas other isolates had very little impact. There was clear correlation between fungal virulence and feeding reduction with virulence explaining nearly 70% of the variation in

  20. Larval habitats of Anopheles gambiae s.s. (Diptera: Culicidae influences vector competence to Plasmodium falciparum parasites

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    Gouagna Louis C

    2007-04-01

    Full Text Available Abstract Background The origin of highly competent malaria vectors has been linked to productive larval habitats in the field, but there isn't solid quantitative or qualitative data to support it. To test this, the effect of larval habitat soil substrates on larval development time, pupation rates and vector competence of Anopheles gambiae to Plasmodium falciparum were examined. Methods Soils were collected from active larval habitats with sandy and clay substrates from field sites and their total organic matter estimated. An. gambiae larvae were reared on these soil substrates and the larval development time and pupation rates monitored. The emerging adult mosquitoes were then artificially fed blood with infectious P. falciparum gametocytes from human volunteers and their midguts examined for oocyst infection after seven days. The wing sizes of the mosquitoes were also measured. The effect of autoclaving the soil substrates was also evaluated. Results The total organic matter was significantly different between clay and sandy soils after autoclaving (P = 0.022. A generalized liner model (GLM analysis identified habitat type (clay soil, sandy soil, or lake water and autoclaving (that reduces presence of microbes as significant factors affecting larval development time and oocyst infection intensities in adults. Autoclaving the soils resulted in the production of significantly smaller sized mosquitoes (P = 0.008. Autoclaving clay soils resulted in a significant reduction in Plasmodium falciparum oocyst intensities (P = 0.041 in clay soils (unautoclaved clay soils (4.28 ± 0.18 oocysts/midgut; autoclaved clay soils = 1.17 ± 0.55 oocysts/midgut although no difference (P = 0.480 in infection rates was observed between clay soils (10.4%, sandy soils (5.3% or lake water (7.9%. Conclusion This study suggests an important nutritional role for organic matter and microbial fauna on mosquito fitness and vector competence. It shows that the quality of

  1. Successful human infection with P. falciparum using three aseptic Anopheles stephensi mosquitoes: a new model for controlled human malaria infection.

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    Matthew B Laurens

    Full Text Available Controlled human malaria infection (CHMI is a powerful method for assessing the efficacy of anti-malaria vaccines and drugs targeting pre-erythrocytic and erythrocytic stages of the parasite. CHMI has heretofore required the bites of 5 Plasmodium falciparum (Pf sporozoite (SPZ-infected mosquitoes to reliably induce Pf malaria. We reported that CHMI using the bites of 3 PfSPZ-infected mosquitoes reared aseptically in compliance with current good manufacturing practices (cGMP was successful in 6 participants. Here, we report results from a subsequent CHMI study using 3 PfSPZ-infected mosquitoes reared aseptically to validate the initial clinical trial. We also compare results of safety, tolerability, and transmission dynamics in participants undergoing CHMI using 3 PfSPZ-infected mosquitoes reared aseptically to published studies of CHMI using 5 mosquitoes. Nineteen adults aged 18-40 years were bitten by 3 Anopheles stephensi mosquitoes infected with the chloroquine-sensitive NF54 strain of Pf. All 19 participants developed malaria (100%; 12 of 19 (63% on Day 11. The mean pre-patent period was 258.3 hours (range 210.5-333.8. The geometric mean parasitemia at first diagnosis by microscopy was 9.5 parasites/µL (range 2-44. Quantitative polymerase chain reaction (qPCR detected parasites an average of 79.8 hours (range 43.8-116.7 before microscopy. The mosquitoes had a geometric mean of 37,894 PfSPZ/mosquito (range 3,500-152,200. Exposure to the bites of 3 aseptically-raised, PfSPZ-infected mosquitoes is a safe, effective procedure for CHMI in malaria-naïve adults. The aseptic model should be considered as a new standard for CHMI trials in non-endemic areas. Microscopy is the gold standard used for the diagnosis of Pf malaria after CHMI, but qPCR identifies parasites earlier. If qPCR continues to be shown to be highly specific, and can be made to be practical, rapid, and standardized, it should be considered as an alternative for diagnosis

  2. Mosquitocidal activity of Polygala arvensis Willd against Aedes aegypti (Linn., Anopheles stephensi (Liston. and Culex quinquefasciatus (Say. (Diptera: Culicidae

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    M. Deepa

    2014-12-01

    Full Text Available To determine the larvicidal, ovicidal and repellent activities of benzene and methanol extract of Polygala arvensis against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus Twenty five 3rd instar larvae of selected mosquitoes species were exposed to various concentrations (60-300 ppm and were assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC50 values of the P. Arvensis leaf extract was determined following Probit analysis. The ovicidal activity was determined against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus exposed to variousconcentrations were tested under laboratory conditions and the hatch rates were assessed 120hrs post treatment. The repellent efficacy was determined against selected mosquitoes at three concentrations viz., 1.0, 2.0 and 3.0 mg/cm2 under the laboratory conditions. The LC50 and LC90 values of benzene and methanol extract of P. arvensis against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus larvae in 24 h were 75.32, 88.26, 82.46, 58.21, 46.37, 42.68 and 260.48, 275.26, 251.39, 208.45, 189.82 and 130.44 ppm, respectively. It has been noticed that the higher concentrations of P. arvensis extractspossesses strong ovicidal activity at 200 ppm concentration against Ae. aegypti, An. stephensi and C. quinquefasciatus, no egg hatchability was recorded. In the same way, methanol extracts showed maximum ovicidal activity followed by benzene extract against selected vector mosquitoes. In repellent activity, among two extracts tested P. arvensis methanol extract had strong repellent action against selected mosquitoes as it provided 100% protection against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus for 280min. From the results it can be concluded the P. arvensis extract was an excellent potential for controlling Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes.

  3. Human antibody response to Anopheles saliva for comparing the efficacy of three malaria vector control methods in Balombo, Angola.

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    Laura Brosseau

    Full Text Available Human antibody (Ab response to Anopheles whole saliva, used as biomarker of Anopheles exposure, was investigated over a period of two years (2008-2009, in children between 2 to 9 years old, before and after the introduction of three different malaria vector control methods; deltamethrin treated long lasting impregnated nets (LLIN and insecticide treated plastic sheeting (ITPS--Zero Fly® (ITPS-ZF, deltamethrin impregnated Durable (Wall Lining (ITPS-DL--Zerovector® alone, and indoor residual spraying (IRS with lambdacyhalothrin alone. These different vector control methods resulted in considerable decreases in all three entomological (82.4%, parasitological (54.8% and immunological criteria analyzed. The highest reductions in the number of Anopheles collected and number of positive blood smears, respectively 82.1% and 58.3%, were found in Capango and Canjala where LLIN and ITPS-ZF were implemented. The immunological data based on the level of anti-saliva IgG Ab in children of all villages dropped significantly from 2008 to 2009, except in Chissequele. These results indicated that these three vector control methods significantly reduced malaria infections amongst the children studied and IRS significantly reduced the human-Anopheles contact. The number of Anopheles, positive blood smears, and the levels of anti-saliva IgG Ab were most reduced when LLIN and ITPS-ZF were used in combination, compared to the use of one vector control method alone, either ITPS-DL or IRS. Therefore, as a combination of two vector control methods is significantly more effective than one control method only, this control strategy should be further developed at a more global scale.

  4. A Study of the Essential Oils of Four Sudanese Accessions of Basil (Ocimum basilicum L. Against Anopheles Mosquito Larvae

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    Azhari H. Nour

    2009-01-01

    Full Text Available Problem statement: Certain basil essential oils were claimed to have a larvicidal activity towards mosquito's larvae. To test this claim the essential oils of four accessions of basil grown in Sudan were selected and tested for Anopheles larvae. Malaria is the major health problem in the Sudan and the whole country is now considered endemic, with varying degrees, about 35,000 deaths every year due to malaria. Anopheles mosquito is the major vector of malaria disease in Sudan. Search for larvicidal active compound(s is one of several attempts to fine effective and affordable ways to control this mosquito. To determine the toxic effects of basil essential oils extracted by steam distillation against Anopheles larvae. Approach: For the larvicidal bioassay, three concentrations (100, 300, 500 ppm of essential oil solutions of four basil accessions were prepared; 1 mL of ethanol was used to solubilize the oil in water (999 mL. In each concentration of oil solution were inserted 20 larvae (third instars. A set of controls using 0.1% ethanol and untreated sets of larvae in (tap water, were also run for comparison. Data were evaluated through regression analysis, from the regression line; the LC50 values were read. The active ingredients were separated and/ or identified by TLC, IR and GC-MS. Results: Larvicidal activity of the essential oils is varied, lasted for about 9 h and thereafter decreased, LC50 values ranging from 190-300 ppm. Linalool, geraniol and eugenol are active components of basil essential oil against Anopheles larvae. Two accessions were caused 100% mortality at a concentration range 300-500 ppm for 3 h. Conclusion: These results indicated that basil essential oils have larvicidal activity towards Anopheles larvae. Therefore, could be affordable way to control this mosquito.

  5. Effect of Novaluron (Rimon 10 EC) on the mosquitoes Anopheles albimanus, Anopheles pseudopunctipennis, Aedes aegypti, Aedes albopictus and Culex quinquefasciatus from Chiapas, Mexico.

    Science.gov (United States)

    Arredondo-Jiménez, J I; Valdez-Delgado, K M

    2006-12-01

    Dengue fever is a serious problem in Mexico and vector control has not been effective enough at preventing outbreaks. Malaria is largely under control, but it is important that new control measures continue to be developed. Novaluron, a novel host-specific insect growth regulator and chitin synthesis inhibitor, has proved to be effective against agricultural pests, but its efficacy against larval mosquito vectors under field conditions remains unknown. In accordance with the World Health Organization Pesticide Evaluation Scheme, phase I, II and III studies were conducted to evaluate the efficacy and residual effect of Novaluron (Rimon 10 EC, Makhteshim, Beer-Sheva, Israel) on the malaria vectors Anopheles albimanus Wiedemann (Diptera: Culicidae) and Anopheles pseudopunctipennis Theobald, the dengue vectors Aedes aegypti (L) and Aedes albopictus Skuse and the nuisance mosquito Culex quinquefasciatus Say. Laboratory susceptibility tests yielded diagnostic concentrations for all five target species. Field trials to identify the optimum field dosage of Novaluron against Anopheles mosquitoes were carried out under semi-natural conditions in artificial plots and in vessels with wild mosquitoes. Efficacy was measured by monitoring mortality of larvae and pupae and the percentage of inhibition of emergence from floating cages. Dosages of Novaluron for field tests were based on pupal LC(99) (lethal concentration 99%) of An. pseudopunctipennis (0.166 mg/L) in plots and average pupal LC(99) of Ae. aegypti and Ae. albopictus (0.55 mg/L). At all dosages tested, Novaluron significantly reduced larval populations of An. albimanus, Culex coronator Dyar & Knab, Ae. albopictus and Cx. quinquefasciatus by approximately 90%, inhibited adult emergence of An. albimanus and An. pseudopunctipennis by approximately 97% for almost 4 months in experimental plots, and inhibited adult emergence of Ae. aegypti and Ae. albopictus by approximately 97% for up to 14 weeks. Recommended dosages of

  6. Detection of the East and West African kdr mutation in Anopheles gambiae and Anopheles arabiensis from Uganda using a new assay based on FRET/Melt Curve analysis

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    Backeljau Thierry

    2006-02-01

    Full Text Available Abstract Background Appropriate monitoring of vector resistance to insecticides is an integral component of planning and evaluation of insecticide use in malaria control programmes. The malaria vectors Anopheles gambiae s.s. and Anopheles arabiensis have developed resistance to pyrethroid insecticides as a result of a mechanism conferring reduced nervous system sensitivity, better known as knockdown resistance (kdr. In An. gambiae s.s. and An. arabiensis, two different substitutions in the para-type sodium channel, a L1014F substitution common in West Africa and a L1014S replacement found in Kenya, are linked with kdr. Two different allele-specific polymerase chain reactions (AS-PCR are needed to detect these known kdr mutations. However, these AS-PCR assays rely on a single nucleotide polymorphism mismatch, which can result in unreliable results. Methods Here, a new assay for the detection of knockdown resistance in An. gambiae s.s. and An. arabiensis based on Fluorescence Resonance Energy Transfer/Melt Curve analysis (FRET/MCA is presented and compared with the existing assays. Results The new FRET/MCA method has the important advantage of detecting both kdr alleles in one assay. Moreover, results show that the FRET/MCA is more reliable and more sensitive than the existing AS-PCR assays and is able to detect new genotypes. By using this technique, the presence of the East African kdr mutation (L1014S is shown for the first time in An. arabiensis specimens from Uganda. In addition, a new kdr genotype is reported in An. gambiae s.s. from Uganda, where four An. gambiae s.s. mosquitoes possess both, the West (L1014F and East (L1014S African kdr allele, simultaneously. Conclusion The presence of both kdr mutations in the same geographical region shows the necessity of a reliable assay that enables to detect both mutations in one single assay. Hence, this new assay based on FRET/MCA will improve the screening of the kdr frequencies in An. gambiae s

  7. Mansonia africana and Mansonia uniformis are Vectors in the transmission of Wuchereria bancrofti lymphatic filariasis in Ghana

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    Ughasi Josephine

    2012-05-01

    Full Text Available Abstract Background Recent data from Ghana indicates that after seven rounds of annual mass drug administration (MDA there is still sustained transmission albeit at low levels in certain areas where Anopheles melas, An. gambiae s.s., Mansonia and Culex species are the main biting mosquitoes. Anopheles gambiae s.l. and An. funestus are the known vectors in Ghana and a recent report indicated that An. melas could transmit at low level microfilaraemia. However, because An. melas is not found everywhere there was the need to determine whether any of the other culicine species could also be playing a role in the transmission of LF. Methods Indoor mosquitoes collected once a month for three months using pyrethrum spray catches in six communities within the Kommenda-Edina-Eguafo-Abirem (KEEA District, Central Region of Ghana were morphologically identified, dissected and examined for the presence of W. bancrofti. Additionally, stored mosquito samples collected during previous years in 8 communities from the Gomoa District also in the Central Region were similarly processed. The identities of all W. bancrofti parasites found were confirmed using an established PCR method. Results A total of 825 indoor resting mosquitoes comprising of 501 Anopheles species, 239 Mansonia species, 84 Culex species and 1 Aedes species were dissected and examined for the presence of W. bancrofti. Mansonia africana had infection and infectivity rates of 2.5%. and 2.1% respectively. Anopheles gambiae s.l. had an infection rate of 0.4% and a similar infectivity rate. None of the Culex sp. and Aedes sp were found with infection. From the stored mosquitoes the infection and infectivity rates for M. africana were 7.6% (N = 144 and 2.8% respectively whilst the corresponding rates for M. uniformis were 2.9% (N = 244 and 0.8%. Conclusions This is the first report of Mansonia species as vectors of lymphatic filariasis (LF in Ghana and in West Africa since that of 1958 in

  8. The automotive transmission book

    CERN Document Server

    Fischer, Robert; Jürgens, Gunter; Najork, Rolf; Pollak, Burkhard

    2015-01-01

    This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors, and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.

  9. Molecular evolution and population genetics of a Gram-negative binding protein gene in the malaria vector Anopheles gambiae (sensu lato)

    OpenAIRE

    Salgueiro, Patrícia; Lopes, Ana Sofia; Mendes, Cristina; Charlwood, Jacques Derek; Arez, Ana Paula; Pinto, João; Silveira, Henrique

    2016-01-01

    Background Clarifying the role of the innate immune system of the malaria vector Anopheles gambiae is a potential way to block the development of the Plasmodium parasites. Pathogen recognition is the first step of innate immune response, where pattern recognition proteins like GNBPs play a central role. Results We analysed 70 sequences of the protein coding gene GNBPB2 from two species, Anopheles gambiae (s.s.) and An. coluzzii, collected in six African countries. We detected 135 segregating ...

  10. Bordetella pertussis transmission.

    Science.gov (United States)

    Trainor, Elizabeth A; Nicholson, Tracy L; Merkel, Tod J

    2015-11-01

    Bordetella pertussis and B. bronchiseptica are Gram-negative bacterial respiratory pathogens. Bordetella pertussis is the causative agent of whooping cough and is considered a human-adapted variant of B. bronchiseptica. Bordetella pertussis and B. bronchiseptica share mechanisms of pathogenesis and are genetically closely related. However, despite the close genetic relatedness, these Bordetella species differ in several classic fundamental aspects of bacterial pathogens such as host range, pathologies and persistence. The development of the baboon model for the study of B. pertussis transmission, along with the development of the swine and mouse model for the study of B. bronchiseptica, has enabled the investigation of different aspects of transmission including the route, attack rate, role of bacterial and host factors, and the impact of vaccination on transmission. This review will focus on B. pertussis transmission and how animal models of B. pertussis transmission and transmission models using the closely related B. bronchiseptica have increased our understanding of B. pertussis transmission.

  11. Identification of one capa and two pyrokinin receptors from the malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Olsen, Stine S; Cazzamali, Giuseppe; Williamson, Michael; Grimmelikhuijzen, Cornelis J P; Hauser, Frank

    2007-10-19

    We cloned the cDNA of three evolutionarily related G protein-coupled receptors from the malaria mosquito Anopheles gambiae and functionally expressed them in Chinese hamster ovary cells. One receptor, Ang-Capa-R, was only activated by the two Anopheles capa neuropeptides Ang-capa-1 (GPTVGLFAFPRVamide) and Ang-capa-2 (pQGLVPFPRVamide) with EC(50) values of 8.6x10(-9)M and 3.3x10(-9)M, respectively, but not by any other known mosquito neuropeptide. The second receptor, Ang-PK-1-R, was selectively activated by the Anopheles pyrokinin-1 peptides Ang-PK-1-1 (AGGTGANSAMWFGPRLamide) and Ang-PK-1-2 (AAAMWFGPRLamide) with EC(50) values of 3.3x10(-8)M and 2.5x10(-8)M, respectively, but not by mosquito capa or pyrokinin-2 peptides. For the third receptor, Ang-PK-2-R, the most potent ligands were the pyrokinin-2 peptides Ang-PK-2-1 (DSVGENHQRPPFAPRLamide) and Ang-PK-2-2 (NLPFSPRLamide) with EC(50) values of 5.2x10(-9)M and 6.4x10(-9)M, respectively. However, this receptor could also be activated by the two pyrokinins-1, albeit with lower potency (EC(50): 2-5x10(-8)M). Because Ang-capa-1 and -2 and Ang-PK-1-1 are located on one preprohormone and the other peptides on another prohormone, these results imply a considerable crosstalk between the capa, pyrokinin-1 and pyrokinin-2 systems. Gene structure and phylogenetic tree analyses showed that Ang-Capa-R was the orthologue of the Drosophila capa receptor CG14575, Ang-PK-1-R the orthologue of the Drosophila pyrokinin-1 receptor CG9918, and Ang-PK-2-R the orthologue of the Drosophila pyrokinin-2 receptors CG8784 and CG8795. This is the first report on the functional characterization and crosstalk properties of capa and pyrokinin receptors in mosquitoes.

  12. Predicting the potential distribution of main malaria vectors Anopheles stephensi, An. culicifacies s.l. and An. fluviatilis s.l. in Iran based on maximum entropy model.

    Science.gov (United States)

    Pakdad, Kamran; Hanafi-Bojd, Ahmad Ali; Vatandoost, Hassan; Sedaghat, Mohammad Mehdi; Raeisi, Ahmad; Moghaddam, Abdolreza Salahi; Foroushani, Abbas Rahimi

    2017-05-01

    Malaria is considered as a major public health problem in southern areas of Iran. The goal of this study was to predict best ecological niches of three main malaria vectors of Iran: Anopheles stephensi, Anopheles culicifacies s.l. and Anopheles fluviatilis s.l. A databank was created which included all published data about Anopheles species of Iran from 1961 to 2015. The suitable environmental niches for the three above mentioned Anopheles species were predicted using maximum entropy model (MaxEnt). AUC (area under Roc curve) values were 0.943, 0.974 and 0.956 for An. stephensi, An. culicifacies s.l. and An. fluviatilis s.l respectively, which are considered as high potential power of model in the prediction of species niches. The biggest bioclimatic contributor for An. stephensi and An. fluviatilis s.l. was bio 15 (precipitation seasonality), 25.5% and 36.1% respectively, followed by bio 1 (annual mean temperature), 20.8% for An. stephensi and bio 4 (temperature seasonality) with 49.4% contribution for An. culicifacies s.l. This is the first step in the mapping of the country's malaria vectors. Hence, future weather situation can change the dispersal maps of Anopheles. Iran is under elimination phase of malaria, so that such spatio-temporal studies are essential and could provide guideline for decision makers for IVM strategies in problematic areas.

  13. SPECIES COMPOSITION OF MALARIAL MOSQUITOES KHARKIV REGION. NATURAL FACTORS OF MALARIA TRANSMISSION

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    Gazzawi - Rogozinа L. V.

    2015-05-01

    Full Text Available Introduction. This article describes the species composition of the dominant Anopheles mosquitoes in the Kharkiv region, the season of their possible effective infection, as well as ongoing anti-malaria activities . Key words: malaria , mosquitoes, p . Anopheles, epidemiology, census, hydraulic events. Material & methods. The analysis of entomological and meteorological situation in Ukraine and in the Kharkiv region according to data of the Ukrainian Center of control and monitoring of diseases of the Ministry of Health of Ukraine and Kharkiv regional laboratory center. Collection of material (imaginal and larval was carried out on the territory of natural and artificial water bodies of Kharkiv region in the period 2013 - 2014. When collecting the material used conventional accounting methods mosquito populations. On the territory of the region under study, we have found 30 species of mosquitoes three genera: Anopheles, Culex, Aedes. Results & discussion. Epidemiological role of each species of mosquitoes depends on several conditions. Dangerous vector species can only be found in large numbers, a significant percentage of individuals in a population that feeds on the blood of man, having a sufficiently long season activity and a sufficient number of females surviving to age possible maturation of sporozoites in their body. In Ukraine, the major carriers - Anopheles maculipennis, An. m. messeae, An. m. atroparvus, An. claviger, An. plumbeus, An. hyrcanus. Mosquito species registered in the territory of the Kharkiv region are susceptible to currently known types of human malaria parasites . Moreover, the dominant species in terms of urban landscapes are An.maculipennis and An.messeae . These species possess all the qualities necessary to be considered dangerous malaria vector control. They are well infected with the three main types of human parasites. In the study area , in terms of urban landscapes, gonoaktivnye females occurs within 3

  14. The impact of insecticides management linked with resistance expression in Anopheles spp. populations

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    Guilherme Liberato da Silva

    2016-07-01

    Full Text Available Abstract The resistance of some species of Anopheles to chemical insecticides is spreading quickly throughout the world and has hindered the actions of prevention and control of malaria. The main mechanism responsible for resistance in these insects appears to be the target site known as knock-down resistance (kdr, which causes mutations in the sodium channel. Even so, many countries have made significant progress in the prevention of malaria, focusing largely on vector control through long-lasting insecticide nets (LLINs, indoor residual spraying and (IRS of insecticides. The objective of this review is to contribute with information on the more applied insecticides for the control of the main vectors of malaria, its effects, and the different mechanisms of resistance. Currently it is necessary to look for others alternatives, e.g. biological control and products derived from plants and fungi, by using other organisms as a possible regulator of the populations of malaria vectors in critical outbreaks.

  15. Cytogenetic evidence for a species complex within Anopheles pseudopunctipennis theobald (Diptera: Culicidae).

    Science.gov (United States)

    Coetzee, M; Estrada-Franco, J G; Wunderlich, C A; Hunt, R H

    1999-04-01

    Anopheles pseudopunctipennis was collected from Acapulco, Mexico and Sallee River, Grenada, West Indies and used in cross-mating experiments. Larvae from the cross, Mexico female X Grenada male, died in the third instar. However, adult progeny were obtained from the reciprocal cross Grenada female x Mexico male. These hybrid males had testes with apparently normal appearance but some without viable sperm. Polytene chromosomes obtained from hybrid females exhibited extensive asynapsis of the X chromosomes. Previously undescribed fixed inversion differences between the two populations were noted on the X chromosome. It is concluded that the two populations belong to different species. The Grenada population is designated An. pseudopunctipennis species C, since it is the third taxon recognized in this species complex.

  16. Anopheles barbirostris Confirmation as Malaria Vector in Waikabubak through the Detection of Circumsporozoit Protein

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    Yuneu Yuliasih

    2012-06-01

    Full Text Available Anopheline species confirmed as malaria vector if the salivary gland contained sporozoites. One of the method to confirmed it was through an Enzyme-Linked Immunosorbent Assay (ELISA. The aim of this study was to investigate the presence of circum sporozoite protein (CSP in the mosquito of Anopheles barbirostris with ELISA method. The study was conducted in malaria endemic area named Modu Waimaringu Village, Waikabubak District, Sumba Barat Regency in March 2011. The study design was cross-sectional study, mosquito for the ELISA test were collected only from animal bait. ELISA method examination used on An. barbirostris body parts (i.e. the head-thorax where sporozoites of P. falciparum or P. Vivax possibly be found. The results showed that 40 samples of An. barbirostris mosquitoes which acquired from the mosquite bait in Modu Waimaringu Village was negative (100%. It means that there was no CSP found and An. barbirostris was not a malaria vector in the area

  17. Genetic Study of Propoxur Resistance—A Carbamate Insecticide in the Malaria Mosquito, Anopheles stephensi Liston

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    D. Sanil

    2010-01-01

    Full Text Available Anopheles stephensi Liston (Diptera: Culicidae is the urban vector of malaria in the Indian subcontinent and several countries of the Middle East. The genetics of propoxur resistance (pr in An. stephensi larvae was studied to determine its mode of inheritance. A diagnostic dose of 0.01 mg/L as recommended by WHO was used to establish homozygous resistant and susceptible strains. Reciprocal crosses between the resistant and susceptible strains showed an F1 generation of incomplete dominance. The progenies of backcrosses to susceptible parents were in 1 : 1 ratio of the same phenotypes as the parents and hybrids involved. The dosage mortality (d-m lines were constructed for each one of the crosses, and the degree of dominance was calculated. It is concluded that propoxur resistance in An. stephensi larvae is due to monofactorial inheritance with incomplete dominance and is autosomal in nature.

  18. Repellency effect of forty-one essential oils against Aedes, Anopheles, and Culex mosquitoes.

    Science.gov (United States)

    Amer, Abdelkrim; Mehlhorn, Heinz

    2006-09-01

    Since ancient times, plant products were used in various aspects. However, their use against pests decreased when chemical products became developed. Recently, concerns increased with respect to public health and environmental security requiring detection of natural products that may be used against insect pests. In this study, 41 plant extracts and 11 oil mixtures were evaluated against the yellow fever mosquito, Aedes aegypti (Linnaeus), the malaria vector, Anopheles stephensi (Liston), and the filariasis and encephalitis vector, Culex quinquefasciatus (Say) (Diptera: Culicidae) using the skin of human volunteers to find out the protection time and repellency. The five most effective oils were those of Litsea (Litsea cubeba), Cajeput (Melaleuca leucadendron), Niaouli (Melaleuca quinquenervia), Violet (Viola odorata), and Catnip (Nepeta cataria), which induced a protection time of 8 h at the maximum and a 100% repellency against all three species. This effect needs, however, a peculiar formulation to fix them on the human skin.

  19. Molecular taxonomy provides new insights into anopheles species of the neotropical arribalzagia series.

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    Giovan F Gómez

    Full Text Available Phylogenetic analysis of partial mitochondrial cytochrome oxidase c subunit I (COI and nuclear internal transcribed spacer 2 (ITS2 sequences were used to evaluate initial identification and to investigate phylogenetic relationships of seven Anopheles morphospecies of the Arribalzagia Series from Colombia. Phylogenetic trees recovered highly supported clades for An. punctimaculas.s., An. calderoni, An. malefactor s.l., An. neomaculipalpus, An. apicimacula s.l., An. mattogrossensis and An. peryassui. This study provides the first molecular confirmation of An. malefactorfrom Colombia and discovered conflicting patterns of divergence for the molecular markers among specimens from northeast and northern Colombia suggesting the presence of two previously unrecognized Molecular Operational Taxonomic Units (MOTUs. Furthermore, two highly differentiated An. apicimacula MOTUs previously found in Panama were detected. Overall, the combined molecular dataset facilitated the detection of known and new Colombian evolutionary lineages, and constitutes the baseline for future research on their bionomics, ecology and potential role as malaria vectors.

  20. Susceptibility of Anopheles maculipennis to different classes of insecticides in West Azarbaijan Province, Northwestern Iran

    Institute of Scientific and Technical Information of China (English)

    Ali; Reza; Chavshin; Farrokh; Dabiri; Hassan; Vatandoost; Mulood; Mohammadi; Bavani

    2015-01-01

    Objective: To determine the susceptibility status of Anopheles maculipennis(An. maculipennis) against the major insecticides used in the health sectors in West Azarbaijan Province, Northwestern Iran.Methods: Unfed 3-5 days old adult females of An. maculipennis were collected across the West Azarbaijan Province and were subjected to evaluation of their susceptibility following World Health Organization recommended protocol against six insecticides(permethrin, deltamethrin, propoxur, bendiocarb, malathion and dieldrin) belonging to four different classes. Results: In this study, 916 specimens of An. maculipennis were examined against the insecticides which indicated that An. maculipennis was tolerant to permethrin, deltamethrin and dielderin, but displayed resistance against propoxur, bendiocarb and malathion. Conclusions: The pattern of resistance in An. maculipennis could be attributed to the agricultural landscapes, agricultural pesticides used and the exposure of the mosquitoes to insecticides. Logical cooperation is needed between the agriculture and health sectors to ensure the judicious use of pesticides in each sector and the management of probable resistance.

  1. Quetzal: a transposon of the Tc1 family in the mosquito Anopheles albimanus.

    Science.gov (United States)

    Ke, Z; Grossman, G L; Cornel, A J; Collins, F H

    1996-10-01

    A member of the Tc1 family of transposable elements has been identified in the Central and South American mosquito Anopheles albimanus. The full-length Quetzal element is 1680 base pairs (bp) in length, possesses 236 bp inverted terminal repeats (ITRs), and has a single open reading frame (ORF) with the potential of encoding a 341-amino-acid (aa) protein that is similar to the transposases of other members of the Tc1 family, particularly elements described from three different Drosophila species. The approximately 10-12 copies per genome of Quetzal are found in the euchromatin of all three chromosomes of A. albimanus. One full-length clone, Que27, appears capable of encoding a complete transposase and may represent a functional copy of this element.

  2. Systematic studies on Anopheles galvaoi Causey, Deane & Deane from the subgenus Nysssorhynchus blanchard (Diptera: Culicidae

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    Maria Anice Mureb Sallum

    2002-12-01

    Full Text Available Anopheles galvaoi, a member of the subgenus Nyssorhynchus, is redescribed based on morphological characters of the adults male and female, fourth-instar larva and pupa. Female, male genitalia, larval and pupal stages are illustrated. Data about medical importance, bionomics, and distribution are given based on literature records. Adult female of An. galvaoi can be easily misidentified as An. benarrochi Gabaldón and An. aquasalis Curry. A few characters are indicated for identifying female and immatures of An. galvaoi. Phylogenetic relationships among An. galvaoi and six other species of the Oswaldoi Subgroup are estimated using COII mtDNA and ITS2 rDNA gene sequences. Lectotype of An. galvaoi, an adult female from Rio Branco, State of Acre, is invalidated.

  3. The genetics of inviability and male sterility in hybrids between Anopheles gambiae and An. arabiensis.

    Science.gov (United States)

    Slotman, M; Della Torre, A; Powell, J R

    2004-05-01

    Male hybrids between Anopheles gambiae and An. arabiensis suffer from hybrid sterility, and inviability effects are sometimes present as well. We examined the genetic basis of these reproductive barriers between the two species, using 21 microsatellite markers. Generally, recessive inviability effects were found on the X chromosome of gambiae that are incompatible with at least one factor on each arabiensis autosome. Inviability is complete when the gambiae and arabiensis inviability factors are hemi- or homozygous. Using a QTL mapping approach, regions that contribute to male hybrid sterility were also identified. The X chromosome has a disproportionately large effect on male hybrid sterility. Additionally, several moderate-to-large autosomal QTL were found in both species. The effect of these autosomal QTL is contingent upon the presence of an X chromosome from the other species. Substantial regions of the autosomes do not contribute markedly to male hybrid sterility. Finally, no evidence for epistatic interactions between conspecific sterility loci was found.

  4. HOUSE-SCALE TRIAL OF FENFLUTHRIN (OMS-2013 AGAINST DDT RESISTANT ANOPHELES ACONITUS IN CENTRAL JAVA

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    Barodji Barodji

    2012-09-01

    Full Text Available Pengujian racun serangga fenfluthrin 5% w.d.p. dengan dosis 20 mg/m2 tingkat perumahan telah dilakukan untuk menanggulangi vektor malaria Anopheles aconitus yang sudah kebal terhadap DDT di desa Sekolo, Kecamatan Boja, Jawa Tengah. Penilaian entomologi dikerjakan dengan cara pengujian hayati kontak langsung, kontak tidak langsung dan penangkapan An. aconitus yang istirahat di dalam kandang pagi hari. Hasil pengujian hayati kontak langsung menunjukkan bahwa umur residu fenfluthrin yang disem­protkan pada permukaan dinding dengan dosis 20 mg/m2 adalah tidak lama (hanya sekitar 1 bulan. Umur residu yang efektip (kematian >70% hanya dipermukaan bambu pada 4 hari setelah penyemprot­an. Pengaruh fumigasi racun serangga ini sangat lemah, kematian hanya sebesar 14% dalam pengujian hayati kontak tidak langsung pada 4 hari setelah penyemprotan.

  5. PRELIMINARY NOTES ON THE DEVELOPMENT OF DDT RESISTANCE IN ANOPHELES CULICIFACIES

    Directory of Open Access Journals (Sweden)

    A.Zaini

    1973-09-01

    Full Text Available Anopheles culicifacies is the vector of malaria in southeastern part of Iran, India, West Pakistan and Ceylon. In 1959 the LC50 % DDT in the Panchmahal district of Gujarat state (India had increased. DDT resistant population of A. culicifacies has been reported from West Pakistan, Burma and Iran. After application of DDT in 1959, the density of A. culicifacies decreased sharply. The susceptibility test carried out in 1963 showed that the LC50 was 0.5%.After DDT spraying, followed by Dieldrin, for about 10 years the density of A. culicifacies was so negligible that it was not possible to perform susceptibility tests. By April and May of 1973 the density of A.culicifacies in Saidabad, Khairabad and Hit in Baluchesten province, Southeast of Iran, increased to about 500 per shelter. The susceptibility tests carried out showed that A. culicfacies is resistant to DDT and susceptible to Dieldrin and Malathion.

  6. Larvicidal activity of oak Quercus infectoria Oliv. (Fagaceae) gall extracts against Anopheles stephensi Liston.

    Science.gov (United States)

    Aivazi, Ali-Ashraf; Vijayan, V A

    2009-06-01

    There is a growing interest in the use of botanical insecticides to reduce the use of synthetic pesticides in order to avoid environmental side effects. Anopheles stephensi is the primary vector of urban malaria, an endemic disease in India. So, an effort to assay An. stephensi larvae with gall extracts of Quercus infectoria was made under laboratory conditions at Mysore. Ethyl-acetate extract was found to be the most effective of all the five extracts tested for larvicidal activity against the fourth instar larvae, with LC(50) of 116.92 ppm followed by gallotannin, n-butanol, acetone, and methanol with LC(50) values of 124.62, 174.76, 299.26, and 364.61 ppm, respectively. The efficacy in killing mosquito larvae may make this plant promising for the development of new botanical larvicide.

  7. Studies on the bionomics of Anopheles dirus (Culicidae: Diptera) in Mudon, Mon State, Myanmar.

    Science.gov (United States)

    Oo, Thin Thin; Storch, Volker; Becker, Norbert

    2002-06-01

    This study examined some environmental factors influencing the larval habitats of Anopheles dirus (breeding in wells) in Mudon, Myanmar, from May 1998 to March 2000. The larval/pupal density was found to be directly proportional to rainfall and indirectly proportional to the well water level. Shade, vegetation and debris on the surface of well water were important factors influencing the abundance of the aquatic stages of An. dirus. Salinity had an inverse correlation with the larval and pupal density. Other mosquito species associated with An. dirus were identified. Important predators of the mosquito larvae were larvivorous fish, damselfly and dragonfly nymphs. All wells examined were lined with lateritic rocks. Chemical analysis of water samples from wells was conducted.

  8. Imidacloprid and Thiamethoxam Induced Mutations in Internal Transcribed Spacer 2 (ITS2) of Anopheles stephensi.

    Science.gov (United States)

    Bhinder, Preety; Chaudhry, Asha; Barna, Bhupinder; Kaur, Satvinderjeet

    2012-05-01

    The present article deals with the polymerase chain reaction (PCR)-based genotoxicity evaluation of neonicotinoid pesticides, imidacloprid and thiamethoxam, by using the genome of a mosquito Anopheles stephensi taken as an experimental model. After treatment of the second instar larvae with LC(20) of the pesticides for 24 h, the induced nucleotide sequence variations in the internal transcribed spacer 2 (ITS2) of freshly hatched unfed control and treated individuals was studied from the sequence alignment data and the mutations in the form of insertion, deletion and substitution of bases were recorded. Measurable differences, indicative of the genetic damage due to imidacloprid and thiamethoxam were observed when ITS2 sequences of control and treated individuals were compared. It was found that imidacloprid-treated individual had 8 deletions, 29 insertions, 18 transitions and 33 transversions, whereas thiamethoxam-treated individual had 10 deletions, 8 insertions, 47 transitions and 68 transversions.

  9. Differential effect of human ivermectin treatment on blood feeding Anopheles gambiae and Culex quinquefasciatus

    DEFF Research Database (Denmark)

    Derua, Yahya A.; Kisinza, William N.; Simonsen, Paul Erik

    2015-01-01

    BACKGROUND: Widespread and large scale use of ivermectin in humans and domestic animals can have unexpected effects on non-target organisms. As a search for a possible explanation for an observed longitudinal decline in density of anopheline vector mosquitoes, but not in Culex quinquefasciatus......, in an area of north-eastern Tanzania which has been exposed to ivermectin mass drug administration, this study assessed and compared the effect of human ivermectin treatment on blood feeding Anopheles gambiae and Cx. quinquefasciatus. METHODS: Consenting adult volunteers were randomized into two groups...... to receive either ivermectin or placebo. Twenty four hours after treatment, one volunteer from each group was concurrently exposed to 50 laboratory reared An. gambiae on one arm and 50 laboratory reared Cx. quinquefasciatus on the other arm for 15-30 minutes. Engorged mosquitoes were maintained on 10...

  10. Effect of ivermectin on the larvae of Anopheles gambiae and Culex quinquefasciatus

    DEFF Research Database (Denmark)

    Derua, Yahya A.; Malongo, Bernard B.; Simonsen, Paul E.

    2016-01-01

    and adsorption to sediments, the ivermectin exposure-risk to aquatic organisms dwelling in different strata of water bodies varies. This study assessed the survival of larvae of Anopheles gambiae Giles and Culex quinquefasciatus Say, when exposed to low concentrations of ivermectin under laboratory conditions......Background: Ivermectin is used extensively globally for treatment of helminthic and ectoparasitic infections in animals and humans. The effect of excreted ivermectin on non-target organisms in aquatic and terrestrial environments has been increasingly reported. Due to its low water solubility....... Methods: A total of 1800 laboratory reared mosquito larvae of each species were used in the bioassays. Twelve replicates were performed, each testing 6 concentrations of ivermectin (0.0, 0.001, 0.01, 0.1, 1.0 and 10.0 parts per million (ppm)) against third instar larvae of An. gambiae and Cx...

  11. PROPOXUR SELECTION OF THE ADULTS OF ANOPHELES STEPHENSI FROM MINAB, SOUTH OF IRAN

    Directory of Open Access Journals (Sweden)

    H. Edalat

    1997-10-01

    Full Text Available Anopheles stephensi is the main malaria vector in south of Iran. It has been known to be resistant to DDT, malathion and dieldrin. After appearance of resistance the area was treated with propoxur, at the rate of 2 g/m2 twice a year for 14 successive years. This species is still susceptible to propoxur. In order to forecast the possibility of development of propoxur resistance in An.stephensi, the females of this species were put under the pressure of propoxur for 14 generations in 1988. Fourteen generations of propoxur selection on the adult females of An.stephensi resulted in an increase in LT60 from 8.5 min to 24.30 minutes, i.e. 2.86 fold increase in tolerance.

  12. Random amplified polymorphic DNA analysis of Anopheles nuneztovari (Diptera: Culicidae from Western and Northeastern Colombia

    Directory of Open Access Journals (Sweden)

    Carmen Elisa Posso

    2003-06-01

    Full Text Available Random amplified polymorphic DNA (RAPD markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8 but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8. According to molecular variance analysis, the genetic distance between populations was significant (phiST 0.1131, P < 0.001. The variation among individuals within populations (phiST 0.8869, P < 0.001was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific.

  13. Anopheles culicifacies breeding in Sri Lanka and options for control through water management

    DEFF Research Database (Denmark)

    Konradsen, F; Matsuno, Y; Amerasinghe, F P

    1998-01-01

    This paper assesses the options for control of malaria vectors through different water management practices in a natural stream in Sri Lanka. The association between water level in the stream and breeding of the immature stages of the primary vector Anopheles culicifacies was investigated...... and the feasibility of using existing irrigation infrastructure to reduce the breeding potential discussed. The most feasible option would be to implement a management routine where water is released periodically from an upstream reservoir to reduce the number of breeding sites downstream. This study indicates...... that by regulating the water level above 20 cm in the stream throughout the dry season the breeding of A. culicifacies could be significantly reduced. The intervention would have only limited impact on the water lost for agriculture and the management input would be minimal. However, for the intervention to work...

  14. Water management for controlling the breeding of Anopheles mosquitoes in rice irrigation schemes in Kenya

    DEFF Research Database (Denmark)

    Mutero, C M; Blank, H; Konradsen, F

    2000-01-01

    between the 4th and 1st instar larvae in the subplots was only 0.08, indicating very low survival rates. In contrast, the 4th/1st instar ratio for subplots with other water management regimes ranged between 0.27 and 0.68, suggesting a correspondingly higher survival than observed with intermittent...... differences among subplots with different water regimes. The average yield per hectare ranged from 4.8-5.3 metric tonnes. The average daily water percolation/seepage rate was 3.6 mm and did not significantly differ among different water management regimes. Further research is necessary to, among other things......An experiment to assess the impact of intermittent irrigation on Anopheles larval populations, rice yields and water use was conducted in the Mwea rice irrigation scheme in Kenya. Four water regimes including intermittent irrigation were tested in a complete randomized block experimental design...

  15. Le système des estérases carboxyliques chez Anopheles stephensi

    OpenAIRE

    Riandey, Marie-France

    1993-01-01

    L'étude des estérases carboxyliques d'#Anopheles stephensi$ a été réalisée par électrophorèse. L'utilisation d'insecticides inhibiteurs des estérases et la modification des conditions opératoires ont permis de mettre en évidence trois classes d'estérases. Un dimorphisme sexuel est observé : dans les deux sexes, on a identifié un gène diallélique codant pour une estérase sensible aux inhibiteurs, mais, chez des mâles uniquement, il existe un autre gène, également diallélique codant pour une au...

  16. Population genetic structure of malaria vector Anopheles stephensi Liston (Diptera: Culicidae).

    Science.gov (United States)

    Gakhar, S K; Sharma, Richa; Sharma, Arvind

    2013-04-01

    Malaria is a complex disease that afflicts human today. Malaria epidemiology is associated with drug resistance in parasite and differential distribution and insecticide resistance in vector. Efforts are being made to eradicate malaria but burden of malaria is still increasing. Vector control is essential for malaria prevention strategies. Knowledge of population genetic structure is pre-requisite for determining prevention strategies particularly using transgenic mosquitoes. Population genetic study can predict level of gene flow between different populations. Anopheles stephensi Liston is urban vector of malaria in Indo-Pakistan subcontinent. About 12% of malaria cases of malaria in India are contributed by A. stephensi. Studies conducted on population genetics of A. stephensi using various markers in different parts of the world are discussed in this communication.

  17. Anopheles gambiae eicosanoids modulate Plasmodium berghei survival from oocyst to salivary gland invasion

    Directory of Open Access Journals (Sweden)

    Susana Ramos

    2014-08-01

    Full Text Available Eicosanoids affect the immunity of several pathogen/insect models, but their role on the Anopheles gambiae response to Plasmodium is still unknown. Plasmodium berghei-infected mosquitoes were injected with an eicosanoid biosynthesis inhibitor, indomethacin (IN, or a substrate, arachidonic acid (AA, at day 7 or day 12 post-infection (p.i.. Salivary gland invasion was evaluated by sporozoite counts at day 21 p.i. IN promoted infection upon sporozoite release from oocysts, but inhibited infection when sporozoites were still maturing within the oocysts, as observed by a reduction in the number of sporozoites reaching the salivary glands. AA treatment had the opposite effect. We show for the first time that An. gambiae can modulate parasite survival through eicosanoids by exerting an antagonistic or agonistic effect on the parasite, depending on its stage of development.

  18. Anopheles gambiae eicosanoids modulate Plasmodium berghei survival from oocyst to salivary gland invasion.

    Science.gov (United States)

    Ramos, Susana; Custódio, Ana; Silveira, Henrique

    2014-08-01

    Eicosanoids affect the immunity of several pathogen/insect models, but their role on the Anopheles gambiae response to Plasmodium is still unknown. Plasmodium berghei-infected mosquitoes were injected with an eicosanoid biosynthesis inhibitor, indomethacin (IN), or a substrate, arachidonic acid (AA), at day 7 or day 12 post-infection (p.i.). Salivary gland invasion was evaluated by sporozoite counts at day 21 p.i. IN promoted infection upon sporozoite release from oocysts, but inhibited infection when sporozoites were still maturing within the oocysts, as observed by a reduction in the number of sporozoites reaching the salivary glands. AA treatment had the opposite effect. We show for the first time that An. gambiae can modulate parasite survival through eicosanoids by exerting an antagonistic or agonistic effect on the parasite, depending on its stage of development.

  19. RESISTANCE OF ANOPHELES STEPHENSI LISTON TO MALATHION IN THE PROVICE OF FARS, SOUTHERN IRAN

    Directory of Open Access Journals (Sweden)

    N.Eshghy

    1985-08-01

    Full Text Available Anopheles Stephensi is an important malaria vector in southern Iran. This species developed resistance to DDT in 1975 and subsequently to dieldrin in 1960. Since 1968 this species has been under pressure of malathin house sprayin. 50% w.d.p. , 2g/m2, 1-2 rounds per year. Susceptibility tests carried out with malathion impregnated papers during 1979 showed that An.stephensi has acquired resistant to malathion too. With regard to the 0.1% propoxur, a study was carried out to obtain base-line data in the localities under routine observations and also the discriminating dosage that could kill 100% of An.stephensi. The objective of the present paper is to summarize and discuss briefly the field investigations concerning insecticide resistance in An.stephensi.

  20. “Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes”

    Science.gov (United States)

    Neafsey, Daniel E.; Waterhouse, Robert M.; Abai, Mohammad R.; Aganezov, Sergey S.; Alekseyev, Max A.; Allen, James E.; Amon, James; Arcà, Bruno; Arensburger, Peter; Artemov, Gleb; Assour, Lauren A.; Basseri, Hamidreza; Berlin, Aaron; Birren, Bruce W.; Blandin, Stephanie A.; Brockman, Andrew I.; Burkot, Thomas R.; Burt, Austin; Chan, Clara S.; Chauve, Cedric; Chiu, Joanna C.; Christensen, Mikkel; Costantini, Carlo; Davidson, Victoria L.M.; Deligianni, Elena; Dottorini, Tania; Dritsou, Vicky; Gabriel, Stacey B.; Guelbeogo, Wamdaogo M.; Hall, Andrew B.; Han, Mira V.; Hlaing, Thaung; Hughes, Daniel S.T.; Jenkins, Adam M.; Jiang, Xiaofang; Jungreis, Irwin; Kakani, Evdoxia G.; Kamali, Maryam; Kemppainen, Petri; Kennedy, Ryan C.; Kirmitzoglou, Ioannis K.; Koekemoer, Lizette L.; Laban, Njoroge; Langridge, Nicholas; Lawniczak, Mara K.N.; Lirakis, Manolis; Lobo, Neil F.; Lowy, Ernesto; MacCallum, Robert M.; Mao, Chunhong; Maslen, Gareth; Mbogo, Charles; McCarthy, Jenny; Michel, Kristin; Mitchell, Sara N.; Moore, Wendy; Murphy, Katherine A.; Naumenko, Anastasia N.; Nolan, Tony; Novoa, Eva M.; O'Loughlin, Samantha; Oringanje, Chioma; Oshaghi, Mohammad A.; Pakpour, Nazzy; Papathanos, Philippos A.; Peery, Ashley N.; Povelones, Michael; Prakash, Anil; Price, David P.; Rajaraman, Ashok; Reimer, Lisa J.; Rinker, David C.; Rokas, Antonis; Russell, Tanya L.; Sagnon, N'Fale; Sharakhova, Maria V.; Shea, Terrance; Simão, Felipe A.; Simard, Frederic; Slotman, Michel A.; Somboon, Pradya; Stegniy, Vladimir; Struchiner, Claudio J.; Thomas, Gregg W.C.; Tojo, Marta; Topalis, Pantelis; Tubio, José M.C.; Unger, Maria F.; Vontas, John; Walton, Catherine; Wilding, Craig S.; Willis, Judith H.; Wu, Yi-Chieh; Yan, Guiyun; Zdobnov, Evgeny M.; Zhou, Xiaofan; Catteruccia, Flaminia; Christophides, George K.; Collins, Frank H.; Cornman, Robert S.; Crisanti, Andrea; Donnelly, Martin J.; Emrich, Scott J.; Fontaine, Michael C.; Gelbart, William; Hahn, Matthew W.; Hansen, Immo A.; Howell, Paul I.; Kafatos, Fotis C.; Kellis, Manolis; Lawson, Daniel; Louis, Christos; Luckhart, Shirley; Muskavitch, Marc A.T.; Ribeiro, José M.; Riehle, Michael A.; Sharakhov, Igor V.; Tu, Zhijian; Zwiebel, Laurence J.; Besansky, Nora J.

    2015-01-01

    Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover, but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. PMID:25554792

  1. Suitability of monotypic and mixed diets for Anopheles hermsi larval development.

    Science.gov (United States)

    Beasley, Donald A; Walton, William E

    2016-06-01

    The developmental time and survival to eclosion of Anopheles hermsi Barr & Guptavanij fed monotypic and mixed diets of ten food types were examined in laboratory studies. Larvae fed monotypic diets containing animal detritus (freeze-dried rotifers, freeze-dried Daphnia pulicaria, and TetraMin® fish food flakes) and the mixotrophic protistan Cryptomonas ovata developed faster and survived better than larvae that were fed other monotypic diets. Survival to adulthood of larvae fed several concentrations of the diatom Planothidium (=Achnanthes) lanceolatum was poor (1% C20 polyunsaturated fatty acids as total fat, but regardless of essential fatty acid content, algae that produced mucilage and filaments that sank out of the feeding zone were poor quality diets.

  2. Genome expression analysis of Anopheles gambiae: responses to injury, bacterial challenge, and malaria infection.

    Science.gov (United States)

    Dimopoulos, George; Christophides, George K; Meister, Stephan; Schultz, Jörg; White, Kevin P; Barillas-Mury, Carolina; Kafatos, Fotis C

    2002-06-25

    The complex gene expression responses of Anopheles gambiae to microbial and malaria challenges, injury, and oxidative stress (in the mosquito and/or a cultured cell line) were surveyed by using cDNA microarrays constructed from an EST-clone collection. The expression profiles were broadly subdivided into induced and down-regulated gene clusters. Gram+ and Gram- bacteria and microbial elicitors up-regulated a diverse set of genes, many belonging to the immunity class, and the response to malaria partially overlapped with this response. Oxidative stress activated a distinctive set of genes, mainly implicated in oxidoreductive processes. Injury up- and down-regulated gene clusters also were distinctive, prominently implicating glycolysis-related genes and citric acid cycle/oxidative phosphorylation/redox-mitochondrial functions, respectively. Cross-comparison of in vivo and in vitro responses indicated the existence of tightly coregulated gene groups that may correspond to gene pathways.

  3. In vitro and in vivo host range of Anopheles gambiae densovirus (AgDNV).

    Science.gov (United States)

    Suzuki, Yasutsugu; Barik, Tapan K; Johnson, Rebecca M; Rasgon, Jason L

    2015-07-29

    AgDNV is a powerful gene transduction tool and potential biological control agent for Anopheles mosquitoes. Using a GFP reporter virus system, we investigated AgDNV host range specificity in four arthropod cell lines (derived from An. gambiae, Aedes albopictus and Drosophila melanogaster) and six mosquito species from 3 genera (An. gambiae, An. arabiensis, An. stephensi, Ae. albopictus, Ae. aegypti and Culex tarsalis). In vitro, efficient viral invasion, replication and GFP expression was only observed in MOS55 An. gambiae cells. In vivo, high levels of GFP were observed in An. gambiae mosquitoes. Intermediate levels of GFP were observed in the closely related species An. arabiensis. Low levels of GFP were observed in An. stephensi, Ae. albopictus, Ae. aegypti and Cx. tarsalis. These results suggest that AgDNV is a specific gene transduction tool for members of the An. gambiae species complex, and could be potentially developed into a biocontrol agent with minimal off-target effects.

  4. [The mosquitocidal efficacy of microcapsules of alpha-cypermethrin against Anopheles sinensis].

    Science.gov (United States)

    Pan, K Y; Ye, B H; Zhi, C L

    1994-01-01

    The efficacy of spraying of alpha-cypermethrin microcapsule for the control of Anopheles sinensis was investigated when alpha-cypermethrin microcapsule was sprayed at 0.5 g/m2, the KT50 was 7.9 min and a 100% of 24 hours' mortality of An. sinensis, the efficacy being similar to that of the emulsion. 180 days after spray, the KT50 was 28.2 min, the 24 hours' mortality was 85.7%, the residual efficacy was 3 times over that of the emulsion. In the mimic field experiment, similar results were obtained. In the field trial, the residual efficacy of the alpha-cypermethrin microcapsule was 5.9 times that of the emulsion. Alpha-cypermethrin microcapsules is recommended as a good formulation of mosquitocide for mosquito control, considering its mosquitocidal efficacy and residual efficacy.

  5. Habitat associations of eastern equine encephalitis transmission in Walton County Florida.

    Science.gov (United States)

    Kelen, Patrick T Vander; Downs, Joni A; Burkett-Cadena, Nathan D; Ottendorfer, Christy L; Hill, Kevin; Sickerman, Stephen; Hernandez, José; Jinright, Joseph; Hunt, Brenda; Lusk, John; Hoover, Victor; Armstrong, Keith; Unnasch, Robert S; Stark, Lillian M; Unnasch, Thomas R

    2012-05-01

    Eastern Equine Encephalitis virus (EEEV; family Togaviridae, genus Alphavirus) a highly pathogenic mosquito-borne virus is endemic to eastern North America. The ecology of EEEV in Florida differs from that in other parts of the United States; EEEV in the northeastern United States is historically associated with freshwater wetlands. No formal test of habitat associations of EEEV in Florida has been reported. Geographical Information Sciences (GIS) was used in conjunction with sentinel chicken EEEV seroconversion rate data as a means to examine landscape features associated with EEEV transmission in Walton County, FL. Sentinel sites were categorized as enzootic, periodically enzootic, and negative based on the number of chicken seroconversions to EEEV from 2005 to 2009. EEEV transmission was then categorized by land cover usage using Arc GIS 9.3. The land classification data were analyzed using the Kruskal-Wallis test for each land use class to determine which habitats may be associated with virus transmission as measured by sentinel chicken seroconversion rates. The habitat class found to be most significantly associated with EEEV transmission was tree plantations. The ecological factor most commonly associated with reduced levels of EEEV transmission was vegetated nonforest wetlands. Culiseta melanura (Coquillett), the species generally considered to be the major enzootic EEEV vector, was relatively evenly distributed across all habitat classes, while Aedes vexans (Meigen) and Anopheles crucians Weidemann were most commonly associated with tree plantation habitats.

  6. Environmental covariates of Anopheles arabiensis in a rice agroecosystem in Mwea, Central Kenya.

    Science.gov (United States)

    Mwangangi, Joseph M; Muturi, Ephantus J; Shililu, Josephat I; Muriu, Simon; Jacob, Benjamin; Kabiru, Ephantus W; Mbogo, Charles M; Githure, John I; Novak, Robert J

    2007-12-01

    Water quality of aquatic habitats is an important determinant of female mosquito oviposition and successful larval development. This study examined the influence of environmental covariates on Anopheles arabiensis mosquito abundance in the Mwea Irrigation Scheme, Central Province of Kenya, prior to implementation of a malaria vector control program. Experimental rice plots were used to examine the environmental covariates responsible for regulating abundance and diversity of the aquatic stages of malaria vectors. Mosquito larval sampling and water quality analysis were done weekly from the flooding stage to the rice maturation stage. Sampling for mosquito larvae was conducted using standard dipping technique. During each larval collection, environmental covariates such as pH, temperature, conductivity, salinity, dissolved oxygen, water depth, and rice stage were measured. Anopheles arabiensis larval density was highest between 1 wk before transplanting and 4 wk after transplanting with peaks at weeks 0, 3, and 8. The fluctuation in values of the various environmental covariates showed characteristic patterns in different rice growth phases depending on the changes taking place due to the agronomic practices. Using a backward linear regression model, the factors that were found to be associated with abundance of An. arabiensis larvae at any of the rice growing phases included the following: dissolved oxygen, pH, turbidity, water depth, rice height, number of rice tillers, salinity, conductivity, and temperature. The environmental covariates associated with abundance of An. arabiensis were associated with early vegetative stage of the rice growth. For effective control of developmental stages of mosquito larvae, the application of larvicides should be done at the vegetative stage and the larvicides should persist until the beginning of the reproductive stage of the rice.

  7. Status of insecticide susceptibility in Anopheles arabiensis from Mwea rice irrigation scheme, Central Kenya

    Directory of Open Access Journals (Sweden)

    Vulule John M

    2006-06-01

    Full Text Available Abstract Background Control of the Anopheline mosquito vectors of malaria by use of insecticides has been shown to impact on both morbidity and mortality due to this disease. Evidence of insecticide resistance in different settings necessitates surveillance studies to allow prompt detection of resistance should it arise and thus enable its management. Possible resistance by Anopheles arabiensis mosquitoes from Mwea rice irrigation scheme in Central Kenya to insecticides in the four classes of insecticides approved by WHO for indoor residual spraying was investigated. Methods Susceptibility to DDT (an organochlorine, fenitrothion (an organophosphate, bendiocarb (a carbamate, lambdacyhalothrin and permethrin (both pyrethroids was tested using standard WHO diagnostic bioassay kits. Bioassays were performed on non-blood fed mosquitoes one- to three-day old. Knockdown was recorded every 10 min and mortality 24 h post-exposure was noted. Results Mortality 24 h post-exposure was 100% for all insecticides except for lambdacyhalothrin, which averaged 99.46%. Knockdown rates at 10 min intervals were not significantly different between the Mwea population and the susceptible KISUMU strain of Anopheles gambiae sensu stricto control. The KDT50 and KDT95 values for the Mwea population were either lower than those for the control or higher by factors of no more than 2 for most comparisons and compared well with those of An. gambiae sensu lato categorized as susceptible in other studies. Conclusion These results suggest that the Mwea population of An. arabiensis is susceptible to all the insecticides tested. This implies that vector control measures employing any of these insecticides would not be hampered by resistance.

  8. Functional characterization of the NF-κB transcription factor gene REL2 from Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    NGO T. HOA; LIANGBIAO ZHENG

    2007-01-01

    The REL2 gene plays an important role in innate immunity against both Gram (+) and Gram (-) bacteria and malaria parasites in Anopheles gambiae, the main vector of malaria in Africa. Through alternative splicing, REL2 produces two protein products, REL2F (with a Rel-homology domain as well as an inhibitory ankyrin repeat region) and REL2S (without the ankyrin repeats). In the immune-competent cell line Sua1B from An. Gambiae, REL2 has been shown to be a key regulator for cecropin A (or CEC1). The high level expression of CEC1 in Sua1B was postulated to be the result of constitutive activation of REL2F. Here we showed that REL2F is indeed processed, albeit at a low level, in the Sua1B cell line. The primary cleavage requires residue 678 (an aspartic acid). Proteolytic cleavage of REL2F can be enhanced by challenge with bacteria Escherichia coli and Bacillus subtilis, but not with fungus Beauveria bassiana. The inducible cleavage can be substantially reduced by RNA interference against PGRP-LC and CASPL1. Over-expression of REL2S or a constitutively active form of REL2F (REL2F380C or REL2F678) in An. Gambiae cell line can further increase expression of CEC1 and other antimicrobial peptide genes. Over-expression of these constitutive active proteins in an immune na?ve cell line, MSQ43, from Anopheles stephensi, results in even more dramatic increased expression of antimicrobial peptides.

  9. Transgenic Expression of the Anti-parasitic Factor TEP1 in the Malaria Mosquito Anopheles gambiae

    Science.gov (United States)

    Hopp, Ann-Katrin; Saenger, Mélanie; Soichot, Julien; Scholze, Heidi; Boch, Jens; Blandin, Stéphanie A.; Marois, Eric

    2017-01-01

    Mosquitoes genetically engineered to be resistant to Plasmodium parasites represent a promising novel approach in the fight against malaria. The insect immune system itself is a source of anti-parasitic genes potentially exploitable for transgenic designs. The Anopheles gambiae thioester containing protein 1 (TEP1) is a potent anti-parasitic protein. TEP1 is secreted and circulates in the mosquito hemolymph, where its activated cleaved form binds and eliminates malaria parasites. Here we investigated whether TEP1 can be used to create malaria resistant mosquitoes. Using a GFP reporter transgene, we determined that the fat body is the main site of TEP1 expression. We generated transgenic mosquitoes that express TEP1r, a potent refractory allele of TEP1, in the fat body and examined the activity of the transgenic protein in wild-type or TEP1 mutant genetic backgrounds. Transgenic TEP1r rescued loss-of-function mutations, but did not increase parasite resistance in the presence of a wild-type susceptible allele. Consistent with previous reports, TEP1 protein expressed from the transgene in the fat body was taken up by hemocytes upon a challenge with injected bacteria. Furthermore, although maturation of transgenic TEP1 into the cleaved form was impaired in one of the TEP1 mutant lines, it was still sufficient to reduce parasite numbers and induce parasite melanization. We also report here the first use of Transcription Activator Like Effectors (TALEs) in Anopheles gambiae to stimulate expression of endogenous TEP1. We found that artificial elevation of TEP1 expression remains moderate in vivo and that enhancement of endogenous TEP1 expression did not result in increased resistance to Plasmodium. Taken together, our results reveal the difficulty of artificially influencing TEP1-mediated Plasmodium resistance, and contribute to further our understanding of the molecular mechanisms underlying mosquito resistance to Plasmodium parasites. PMID:28095489

  10. Bendiocarb, a potential alternative against pyrethroid resistant Anopheles gambiae in Benin, West Africa

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    Irish Seth

    2010-07-01

    Full Text Available Abstract Background Anopheles gambiae, the main malaria vector in Benin has developed high level of resistance to pyrethroid insecticides, which is a serious concern to the future use of long-lasting insecticidal nets (LLIN and indoor residual spraying (IRS. In this context, one of the pathways available for malaria vector control would be to investigate alternative classes of insecticides with different mode of action than that of pyrethroids. The goal of this study was to evaluate under field conditions the efficacy of a carbamate (bendiocarb and an organophosphate (fenitrothion against pyrethroid-resistant An. gambiae s.s. Methods Wild populations and females from laboratory colonies of five days old An. gambiae were bio-assayed during this study. Two pyrethroids (deltamethrin and alphacypermethrin, an organophosphate (fenitrothion, a carbamate (bendiocarb and a mixture of an organophosphate (chlorpyriphos + a pyrethroid deltamethrin were compared in experimental huts as IRS treatments. Insecticides were applied in the huts using a hand-operated compression sprayer. The deterrency, exophily, blood feeding rate and mortality induced by these insecticides against An. gambiae were compared to the untreated control huts. Results Deltamethrin, alphacypermethrin and bendiocarb treatment significantly reduced mosquito entry into the huts (p An. gambiae (in the first month and 77.8% (in the fourth month. Bendiocarb and the mixture chlorpyriphos/deltamethrin mortality rates ranged from 97.9 to 100% the first month and 77.7-88% the third month respectively. Conclusion After four months, fenitrothion, bendiocarb and the mixture chlorpyriphos/deltamethrin performed effectively against pyrethroid-resistant Anopheles. These results showed that bendiocarb could be recommended as an effective insecticide for use in IRS operations in Benin, particularly as the mixture chlorpyriphos/deltamethrin does not have WHOPES authorization and complaints were mentioned

  11. Biochemical basis of permethrin resistance in Anopheles arabiensis from Lower Moshi, north-eastern Tanzania

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    Oxborough Richard M

    2010-07-01

    Full Text Available Abstract Background Development of resistance to different classes of insecticides is a potential threat to malaria control. With the increasing coverage of long-lasting insecticide-treated nets in Tanzania, the continued monitoring of resistance in vector populations is crucial. It may facilitate the development of novel strategies to prevent or minimize the spread of resistance. In this study, metabolic-based mechanisms conferring permethrin (pyrethroid resistance were investigated in Anopheles arabiensis of Lower Moshi, Kilimanjaro region of north-eastern Tanzania. Methods WHO susceptibility test kits were used to detect resistance to permethrin in An. arabiensis. The levels and mechanisms of permethrin resistance were determined using CDC bottle bioassays and microplate (biochemical assays. In bottle bioassays, piperonyl butoxide (PBO and s,s,s-tributyl phosphorotrithioate (DEF were used as synergists to inhibit mixed function oxidases and non-specific esterases respectively. Biochemical assays were carried out in individual mosquitoes to detect any increase in the activity of enzymes typically involved in insecticide metabolism (mixed function oxidases, α- and β-esterases. Results Anopheles arabiensis from the study area was found to be partially resistant to permethrin, giving only 87% mortality in WHO test kits. Resistance ratios at KT50 and KT95 were 4.0 and 4.3 respectively. The permethrin resistance was partially synergized by DEF and by PBO when these were mixed with permethrin in bottle bioassays and was fully synergized when DEF and PBO were used together. The levels of oxidase and β-esterase activity were significantly higher in An. arabiensis from Lower Moshi than in the laboratory susceptible strain. There was no difference in α-esterase activity between the two strains. Conclusion Elevated levels of mixed function oxidases and β-esterases play a role in detoxification of permethrin in the resistant An. arabiensis population

  12. Evolutionary dynamics of the Ty3/gypsy LTR retrotransposons in the genome of Anopheles gambiae.

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    Jose Manuel C Tubio

    Full Text Available Ty3/gypsy elements represent one of the most abundant and diverse LTR-retrotransposon (LTRr groups in the Anopheles gambiae genome, but their evolutionary dynamics have not been explored in detail. Here, we conduct an in silico analysis of the distribution and abundance of the full complement of 1045 copies in the updated AgamP3 assembly. Chromosomal distribution of Ty3/gypsy elements is inversely related to arm length, with densities being greatest on the X, and greater on the short versus long arms of both autosomes. Taking into account the different heterochromatic and euchromatic compartments of the genome, our data suggest that the relative abundance of Ty3/gypsy LTRrs along each chromosome arm is determined mainly by the different proportions of heterochromatin, particularly pericentric heterochromatin, relative to total arm length. Additionally, the breakpoint regions of chromosomal inversion 2La appears to be a haven for LTRrs. These elements are underrepresented more than 7-fold in euchromatin, where 33% of the Ty3/gypsy copies are associated with genes. The euchromatin on chromosome 3R shows a faster turnover rate of Ty3/gypsy elements, characterized by a deficit of proviral sequences and the lowest average sequence divergence of any autosomal region analyzed in this study. This probably reflects a principal role of purifying selection against insertion for the preservation of longer conserved syntenyc blocks with adaptive importance located in 3R. Although some Ty3/gypsy LTRrs show evidence of recent activity, an important fraction are inactive remnants of relatively ancient insertions apparently subject to genetic drift. Consistent with these computational predictions, an analysis of the occupancy rate of putatively older insertions in natural populations suggested that the degenerate copies have been fixed across the species range in this mosquito, and also are shared with the sibling species Anopheles arabiensis.

  13. [The distribution of the mosquitoes of the Anopheles maculipennis complex (Diptera, Culicidae, Anophelinae) in Central Asia].

    Science.gov (United States)

    Zvantsov, A B; Gordeev, M I; Goriacheva, I I; Ezhov, M N

    2014-01-01

    The polymerase chain reaction-restriction fragment length polymorphism method, cytogenetic analysis, and investigation of egg exochorion have indicated that three representatives of the Anopheles maculipennis complex (subgenus Anopheles): An artemievi Gordeev et al., An. messeae Falleroni, and An. marinius Shingarev. An. messeae is a European-Siberian species that has extended the southern border of its habitat and has been distributed in the south of Kazakhstan and in the north of Kyrgyzstan. In, Kyrgyzstan, An. messeae inhabiting the plains of Europe and Siberia is encountered rather high up in the mountains: the highest point where this species is found is at 1,879 m above sea level. An. artemievi is present in the highland and piedmont regions of Central Asia (Uzbekistan, Kyrgyzstan, southern Kazakhstan, and northern Tajikistan) and in the intermountain basins (Naryn and Fergana ones). The single finding of this species is in south-eastern Turkmenistan. On the contrary, An. martinius tends to be in the plains and occurs in north-eastern Turkmenistan, Karakalpakstan, and Kazakhstan (Kzyl-Orda). On the other hand, a population of this species is found in proximity to the foothills of the Gissar Range in the east of Uzbekistan. An.maculipennis s.str. is not seen in Central Asia. Early evidence for the presence of both An. maculipennis s.str. and An. martinius in Kopet Dag (Southern Turkmenistan) is rather questionable. It is not improbable that these data are appropriate for either the newly described species An.persiensis or the scientifically new representative of the An. maculipennis complex.

  14. The effects of urbanization on global Plasmodium vivax malaria transmission

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    Qi Qiuyin

    2012-12-01

    Full Text Available Abstract Background Many recent studies have examined the impact of urbanization on Plasmodium falciparum malaria endemicity and found a general trend of reduced transmission in urban areas. However, none has examined the effect of urbanization on Plasmodium vivax malaria, which is the most widely distributed malaria species and can also cause severe clinical syndromes in humans. In this study, a set of 10,003 community-based P. vivax parasite rate (PvPR surveys are used to explore the relationships between PvPR in urban and rural settings. Methods The PvPR surveys were overlaid onto a map of global urban extents to derive an urban/rural assignment. The differences in PvPR values between urban and rural areas were then examined. Groups of PvPR surveys inside individual city extents (urban and surrounding areas (rural were identified to examine the local variations in PvPR values. Finally, the relationships of PvPR between urban and rural areas within the ranges of 41 dominant Anopheles vectors were examined. Results Significantly higher PvPR values in rural areas were found globally. The relationship was consistent at continental scales when focusing on Africa and Asia only, but in the Americas, significantly lower values of PvPR in rural areas were found, though the numbers of surveys were small. Moreover, except for the countries in the Americas, the same trends were found at national scales in African and Asian countries, with significantly lower values of PvPR in urban areas. However, the patterns at city scales among 20 specific cities where sufficient data were available were less clear, with seven cities having significantly lower PvPR values in urban areas and two cities showing significantly lower PvPR in rural areas. The urban–rural PvPR differences within the ranges of the dominant Anopheles vectors were generally, in agreement with the regional patterns found. Conclusions Except for the Americas, the patterns of significantly lower

  15. Understanding ebola virus transmission.

    Science.gov (United States)

    Judson, Seth; Prescott, Joseph; Munster, Vincent

    2015-02-03

    An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.

  16. Series Transmission Line Transformer

    Science.gov (United States)

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  17. Effects of Anti-Mosquito Salivary Glands and Deglycosylated Midgut Antibodies of Anopheles stephensi on Fecundity and Longevity

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    H Mohammadzadeh Hajipirloo

    2005-09-01

    Full Text Available With the aim of controlling malaria by reducing vector population, the effects of antibodies produced against salivary glands and deglycosylated midgut antigens of Anopheles stephensi mosquitoes on fecundity and longevity of the same species were tested. Three deglycosylated preparations of midgut and two preparations of salivary glands were produced, conjugated with aluminum hydroxide gel, and subcutaneously injected to shoulders of TO (Turner Out-bred mice. After 4 immunizations and assurance of enough antibody production against utilized antigenic suspensions, effects of blood feeding on immunized and control mice were assayed. Insoluble preparation of midgut showed the strongest effect with 23.5% reduction in egg laying, and increasing death rate of vectors in third day after feeding. No significant reduction in fecundity or survivorship was seen with other preparations. Anopheles midgut insoluble antigens are potential candidates for designing vaccines against malaria vectors and further investigations need to be done to find effective antigens and the best way of their use.

  18. Global climate change and its potential impact on disease transmission by salinity-tolerant mosquito vectors in coastal zones.

    Science.gov (United States)

    Ramasamy, Ranjan; Surendran, Sinnathamby Noble

    2012-01-01

    Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with 30 ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross-McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal transmission of mosquito-borne diseases

  19. Remotely-sensed land use patterns and the presence of Anopheles larvae (Diptera: Culicidae) in Sukabumi, West Java, Indonesia.

    Science.gov (United States)

    Stoops, Craig A; Gionar, Yoyo R; Shinta; Sismadi, Priyanto; Rachmat, Agus; Elyazar, Iqbal F; Sukowati, Supratman

    2008-06-01

    Land use patterns and the occurrence of Anopheles species larvae were studied in Sukabumi District, West Java, Indonesia, from October 2004 to September 2005. Two land use maps derived using remote sensing were used. One map derived from Quickbird satellite images of 150 km2 of the Simpenan and Ciemas subdistricts (106 degrees 27' 53"-106 degrees 38' 38" E and 6 degrees 59' 59"-7 degrees 8' 46" S) in Sukabumi and one using ASTER images covering 4,000 km2 of Sukabumi District from 106 degrees 22' 15"-107 degrees 4' 1" E and 6 degrees 42' 50" - 7 degrees 26' 13" S. There was a total of 11 Anopheles spp. collected from 209 sampling locations in the area covered by the Quickbird image and a total of 15 Anopheles spp. collected from 1,600 sampling locations in the area covered by the ASTER map. For the area covered by the land use maps, ten species were found to have statistically positive relationships between land use class and species presence: Anopheles aconitus, An. annularis, An. barbirostris. An. flavirostris, An. insulaeflorum, An. kochi, An. maculatus, An. subpictus, An. sundaicus, and An. vagus. Quickbird and ASTER satellite images both produced land maps that were adequate for predicting species presence in an area. The land use classes associated with malaria vector breeding were rice paddy (An. aconitus, An. subpictus), plantation located near or adjacent to human settlements (An. maculatus), bush/shrub (An. aconitus, An. maculatus, An. sundaicus), bare land, and water body land use on the coast located < or = 250 m of the beach (An. sundaicus). Understanding the associations of habitat and species in one area, predictions of species presence or absence can be made prior to a ground survey allowing for accurate vector survey and control planning.

  20. INSECTICIDAL ACTIVITIES OF ESSENTIAL OILS EXTRACTED FROM THREE SPECIES OF POACEAE ON ANOPHELES GAMBIAE SPP, MAJOR VECTOR OF MALARIA

    Directory of Open Access Journals (Sweden)

    Dominique C. K. Sohounhloué

    2010-12-01

    Full Text Available In this paper, the insecticidal activities on Anopheles gambiae spp of the essential oils (EO extracted from the dry leaves of some species collected in Benin were studied. The essential oil yields are 2.8, 1.7 and 1.4�0respectively for Cymbopogon schoanenthus (L. Spreng (CS, Cymbopogon citratus Stapf. (CC and Cymbopogon giganteus (Hochst. Chiov (CG. The GC/MS analysis showed that the EO of CS had a larger proportion in oxygenated monoterpenes (86.3�20whereas those of the sheets of CC and CG are relatively close proportions (85.5�0and 82.7�0respectively with. The piperitone (68.5�  2-carene (11.5� and -eudesmol (4.6�20are the major components of the EO of CS while trans para-mentha-1(7,8-dien-2-ol (31.9� trans para-mentha-2,8-dien-1-ol (19.6� cis para-mentha-2,8-dien-1-ol (7.2� trans piperitol (6.3�20and limonene (6.3�20prevailed in the EO of CG. The EO of CC revealed a rich composition in geranial (41.3� neral (33� myrcene (10.4� and geraniol (6.6� The biological tests have shown that these three EO induced 100�0mortality of Anopheles gambiae to 1.1, 586.58 and 1549 µg•cm-2 respectively for CC, CS and CG. These effects are also illustrated by weak lethal concentration for 50�0anopheles population (CC: 0.306; CS: 152.453 and CG: 568.327 µg•cm-2 in the same order of reactivity. The EO of CC appeared most active on two stocks (sensitive and resistant of Anopheles gambiae.

  1. Scanning electron microscopic (Sem studies on fourth instar larva and pupa of Anopheles (Cellia stephensi Liston (Anophelinae: Culicidae

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    Jagbir Singh Kirti

    2014-12-01

    Full Text Available Anopheles (Cellia stephensi Liston is a major vector species of malaria in Indian subcontinent. Taxonomists have worked on its various morphological aspects and immature stages to explore additional and new taxonomic attributes. Scanning electron microscopic (SEM studies have been conducted on the fourth instar larva and pupa of An. stephensi to find additional taxonomic features for the first time from Punjab state.

  2. Species-richness of the Anopheles annulipes Complex (Diptera: Culicidae) Revealed by Tree and Model-Based Allozyme Clustering Analyses

    Science.gov (United States)

    2007-01-01

    and systematics ofAnopheles: insights from a molecular phy· logeny of Australasian mosquitoes. Molecular Phylogenetics and Evolution 9: 262-275. Foley... systematics and pop- ulation studies. Sydney: Academic Press. Roscnberg NA, Burke T, Elo K, Feldman MW, Freidlin PJ, Groenen MAM, Hillel J, Maki·Taniia...of molecular-functional variation patterns among butterfly species complexes IColias: Lepidoptera , Pieridae). Molecular Ecology 12: 1265-1275. © 2007

  3. Bayesian coclustering of Anopheles gene expression time series: Study of immune defense response to multiple experimental challenges

    OpenAIRE

    Heard, Nicholas A.; Holmes, Christopher C.; Stephens, David A.; Hand, David J.; Dimopoulos, George

    2005-01-01

    We present a method for Bayesian model-based hierarchical coclustering of gene expression data and use it to study the temporal transcription responses of an Anopheles gambiae cell line upon challenge with multiple microbial elicitors. The method fits statistical regression models to the gene expression time series for each experiment and performs coclustering on the genes by optimizing a joint probability model, characterizing gene coregulation between multiple experiments. We compute the mo...

  4. Mosquito Larvicidal Potential of Gossypium hirsutum (Bt cotton) Leaves Extracts against Aedes aegypti and Anopheles stephensi larvae.

    OpenAIRE

    Patil, Chandrashekhar D; Hemant P Borase; Salunkhe, Rahul B; Rahul K Suryawanshi; Narkhade, Chandrakant P; Salunke, Bipinchandra K.; Satish V Patil

    2014-01-01

    Background: We aimed to extract the ingredients from leaves of Gossypium hirsutum (Bt cotton) using different solvents and evaluate for potential use to control different larval stages of mosquito species, Aedes aegypti and Anopheles stephensi. Methods: Qualitative and quantitative estimation of ingredients from Go. hirsutum (Bt) plant extract was carried out and their inhibitory action against mosquito larvae was determined using mosquito larvicidal assay. Results: LC50 values of water, etha...

  5. Larvicidal and repellent properties of Adansonia digitata against medically important human malarial vector mosquito Anopheles stephensi (Diptera: Culicidae)

    OpenAIRE

    K. Krishnappa , K. Elumalai , S. Dhanasekaran & J. Gokulakrishnan

    2012-01-01

    Background & objectives: Development of plant-based alternative compounds for mosquito control has gainedimportance now-a-days, in view of increasing resistance in mosquito vectors to existing insecticides. The larvicidaland repellent activities of benzene, chloroform, hexane and methanol leaf extracts of Indian medicinal plant,Adansonia digitata were investigated against malarial vector, Anopheles stephensi.Methods: In all, 25 III instar larvae of An. stephensi were exposed to various concen...

  6. Alstonia boonei De Wild oil extract in the management of mosquito (Anopheles gambiae), a vector of malaria disease

    OpenAIRE

    Kayode David Ileke; Olaniyi Charles Ogungbite

    2015-01-01

    Objective: To evaluate the insecticidal potential of Alstonia boonei (A. boonei) oils and derivatives against different life stages of a malaria vector, Anopheles gambiae. Methods: The leaf, stem bark and root bark of A. boonei were collected from an open field and air dried before being blended to fine powder. Oils from this plant were extracted by cold extraction and were prepared at different concentrations. Contact toxicity of A. boonei was tested against the larvae an...

  7. Dissecting the organ specificity of insecticide resistance candidate genes in Anopheles gambiae: known and novel candidate genes

    OpenAIRE

    2014-01-01

    Background The elevated expression of enzymes with insecticide metabolism activity can lead to high levels of insecticide resistance in the malaria vector, Anopheles gambiae. In this study, adult female mosquitoes from an insecticide susceptible and resistant strain were dissected into four different body parts. RNA from each of these samples was used in microarray analysis to determine the enrichment patterns of the key detoxification gene families within the mosquito and to identify additio...

  8. The Anopheles gambiae detoxification chip: A highly specific microarray to study metabolic-based insecticide resistance in malaria vectors

    OpenAIRE

    2005-01-01

    Metabolic pathways play an important role in insecticide resistance, but the full spectra of the genes involved in resistance has not been established. We constructed a microarray containing unique fragments from 230 Anopheles gambiae genes putatively involved in insecticide metabolism [cytochrome P450s (P450s), GSTs, and carboxylesterases and redox genes, partners of the P450 oxidative metabolic complex, and various controls]. We used this detox chip to monitor the expression of the detoxify...

  9. Impact of insecticide-treated nets on wild pyrethroid resistant Anopheles epiroticus population from southern Vietnam tested in experimental huts

    OpenAIRE

    Trung Ho; Speybroeck Niko; Berkvens Dirk; Chinh Vu; Van Bortel Wim; Coosemans Marc

    2009-01-01

    Abstract Background In this study, the efficacy of insecticide-treated nets was evaluated in terms of deterrence, blood-feeding inhibition, induced exophily and mortality on a wild resistant population of Anopheles epiroticus in southern Vietnam, in order to gain insight into the operational consequences of the insecticide resistance observed in this malaria vector in the Mekong delta. Method An experimental station, based on the model of West Africa and adapted to the behaviour of the target...

  10. Transmission-blocking activity of antibodies to Plasmodium falciparum GLURP.10C chimeric protein formulated in different adjuvants

    DEFF Research Database (Denmark)

    Roeffen, Will; Theisen, Michael; van de Vegte-Bolmer, Marga;

    2015-01-01

    BACKGROUND: Plasmodium falciparum is transmitted from person to person by Anopheles mosquitoes after completing its sexual reproductive cycle within the infected mosquito. An efficacious vaccine holds the potential to interrupt development of the parasite in the mosquito leading to control...... and possibly eradication of malaria. A multi-component, R0.10C, was developed comprising P. falciparum glutamate-rich protein (R0) fused in frame to a correctly folded fragment of Pfs48/45 (10C). Here, a series of novel adjuvants were screened for their ability to elicit transmission-blocking (TB) antibodies...

  11. Spectral and HRTEM analyses of Annona muricata leaf extract mediated silver nanoparticles and its Larvicidal efficacy against three mosquito vectors Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti.

    Science.gov (United States)

    Santhosh, Shanthi Bhupathi; Ragavendran, Chinnasamy; Natarajan, Devarajan

    2015-12-01

    Mosquitoes transmit various diseases which mainly affect the human beings and every year cause millions of deaths globally. Currently available chemical and synthetic mosquitocidal agents pose severe side effects, pollute the environment vigorously, and become resistance. There is an urgent need to identify and develop the cost effective, compatible and eco-friendly product for mosquito control. The present study was aimed to find out the larvicidal potential of aqueous crude extract and green synthesized silver nanoparticles (AgNPs) from Annona muricata leaves were tested against fourth instar larvae of three important mosquitoes i.e. Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti using different concentrations of AgNPs (10, 20, 30, 40 and 50 ppm) and the aqueous leaf extract (100, 200, 300, 400, and 500 ppm) for 24 and 48 h. The maximum mortality was noticed in AgNPs than aqueous leaf extract of A. muricata against tested mosquitoes with least LC50 values of 37.70, 31.29, and 20.65 ppm (24h) and 546.7, 516.2, and 618.4 ppm (48 h), respectively. All tested concentrations of AgNps exhibited 100% mortality in A. aegypti larvae at 48 hour observation. In addition, the plant mediated AgNPs were characterized by UV-vis spectrum, Fourier transform infrared spectroscopy, particle size analyser, X-ray diffraction, high resonance transmission electron microscopy, and energy-dispersive X-ray spectroscopy analysis for confirmation of nanoparticle synthesis. Based on the findings of the study suggests that the use of A. muricata plant mediated AgNPs can act as an alternate insecticidal agents for controlling target mosquitoes.

  12. Larvicidal potential of silver nanoparticles synthesized using fungus Cochliobolus lunatus against Aedes aegypti (Linnaeus, 1762) and Anopheles stephensi Liston (Diptera; Culicidae).

    Science.gov (United States)

    Salunkhe, Rahul B; Patil, Satish V; Patil, Chandrashekhar D; Salunke, Bipinchandra K

    2011-09-01

    Larvicides play a vital role in controlling mosquitoes in their breeding sites. The present study was carried out to establish the larvicidal activities of mycosynthesized silver nanoparticles (AgNPs) against vectors: Aedes aegypti and Anopheles stephensi responsible for diseases of public health importance. The AgNPs synthesized by filamentous fungus Cochliobolus lunatus, characterized by UV-Vis spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The characterization studies confirmed the spherical shape and size (3-21 nm) of silver nanoparticles. The efficacy of mycosynthesized AgNPs at all the tested concentrations (10, 5, 2.5, 1.25, 0.625, and 0.3125 ppm) against second, third, and fourth instar larvae of A. aegypti (LC(50) 1.29, 1.48, and 1.58; LC(90) 3.08, 3.33, and 3.41 ppm) and against A. stephensi (LC(50) 1.17, 1.30, and 1.41; LC(90) 2.99, 3.13, and 3.29 ppm) were observed, respectively. The mortality rates were positively correlated with the concentration of AgNPs. Significant (P against fourth instar larvae of A. aegypti and A. stephensi. The possible larvicidal activity may be due to penetration of nanoparticles through membrane. Toxicity studies carried out against non-target fish species Poecilia reticulata, the most common organism in the habitats of A. aegypti and A. stephensi showed no toxicity at LC50 and LC90 doses of the AgNPs. This is the first report on mosquito larvicidal activity of mycosynthesized nanoparticles. Thus, the use of fungus C. lunatus to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach and the AgNps formed can be potential mosquito larvicidal agents.

  13. Mosquito larvicidal activity of silver nanoparticles synthesised using actinobacterium, Streptomyces sp. M25 against Anopheles subpictus, Culex quinquefasciatus and Aedes aegypti.

    Science.gov (United States)

    Shanmugasundaram, T; Balagurunathan, R

    2015-12-01

    The present work reports the larvicidal potential of microbially synthesised silver nanoparticles (AgNPs) by using an actinobacterium, Streptomyces sp. M25 isolated from Western Ghats, Tamil Nadu, India. The biomass of Streptomyces sp. was exposed to 1 mM silver nitrate (AgNO3) solution. The synthesis of AgNPs was confirmed by visual inspection followed by instrumental analysis such as UV-vis spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy, scanning electron microscopy, atomic force microscopy and transmission electron microscopy (TEM) with selected area electron diffraction. Based on the TEM and XRD analysis, the average size of the AgNPs was determined to be 10-35 nm. The biosynthesised AgNPs exhibited significant larvicidal activity against malarial vector, Anopheles subpictus (LC50 51.34 mg/L and χ (2) value of 8.228), filarial vector, Culex quinquefasciatus (LC50 48.98 mg/L and χ (2) value of 14.307) and dengue vector, Aedes aegypti (LC50 60.23 mg/L and χ (2) value of 4.042), respectively. Similarly, AgNO3 had larvicidal activity against malarial vector, A. subpictus (LC50 42.544 mg/L and χ (2) value of 2.561), filarial vector, C. quinquefasciatus (LC50 44.922 mg/L and χ (2) value of 1.693) and dengue vector, A. aegypti (LC50 39.664 mg/L and χ (2) value of 5.724), respectively. The current study is a rapid, cost effective, eco-friendly and single step approach. The Streptomyces sp. M25 is a newly added source for the synthesis of AgNPs with improved larvicidal activity.

  14. The Role of Oxidative Stress in the Longevity and Insecticide Resistance Phenotype of the Major Malaria Vectors Anopheles arabiensis and Anopheles funestus.

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    Shüné V Oliver

    Full Text Available Oxidative stress plays numerous biological roles, both functional and pathological. The role of oxidative stress in various epidemiologically relevant biological traits in Anopheles mosquitoes is not well established. In this study, the effects of oxidative stress on the longevity and insecticide resistance phenotype in the major malaria vector species An. arabiensis and An. funestus were examined. Responses to dietary copper sulphate and hydrogen peroxide were used as proxies for the oxidative stress phenotype by determining the effect of copper on longevity and hydrogen peroxide lethal dose. Glutathione peroxidase and catalase activities were determined colorimetrically. Oxidative burden was quantified as protein carbonyl content. Changes in insecticide resistance phenotype were monitored by WHO bioassay. Insecticide resistant individuals showed an increased capacity for coping with oxidative stress, mediated by increased glutathione peroxidase and catalase activity. This effect was observed in both species, as well as in laboratory strains and F1 individuals derived from wild-caught An. funestus mothers. Phenotypic capacity for coping with oxidative stress was greatest in strains with elevated Cytochrome P450 activity. Synergism of oxidative stress defence enzymes by dietary supplementation with haematin, 3-Amino-1, 2, 4-triazole and Sodium diethyldithiocarbamate significantly increased pyrethroid-induced mortality in An. arabiensis and An. funestus. It is therefore concluded that defence against oxidative stress underlies the augmentation of the insecticide resistance phenotype associated with multiple blood-feeding. This is because multiple blood-feeding ultimately leads to a reduction of oxidative stress in insecticide resistant females, and also reduces the oxidative burden induced by DDT and pyrethroids, by inducing increased glutathione peroxidase activity. This study highlights the importance of oxidative stress in the longevity and

  15. Espécies de Anopheles (Culicidae, Anophelinae em área endêmica de malária, Maranhão, Brasil

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    Maria M dos SP Xavier

    1999-12-01

    Full Text Available OBJETIVO: Estudar a flutuação sazonal, freqüência horária, abundância relativa e riqueza de espécies de Anopheles em ambiente antrópico, para entender a bioecologia do grupo e para a monitorização do programa de controle da malária. MÉTODOS: Os anofelinos foram estudados durante um ano, de outubro de 1996 a setembro de 1997, das 18 às 6 horas, a cada 30 dias, no Município da Raposa, Ilha de São Luís, Maranhão. Utilizou-se o método de captura de fêmeas em iscas humanas no intra e peridomicílio, com tubo de sucção e foco luminoso orientado. RESULTADOS: Foram coletados 1.407 espécimes assim distribuídos: Anopheles aquasalis (82%, Anopheles galvaoi (10,2% e Anopheles albitarsis (6,4%. As demais espécies, Anopheles evansae, Anopheles nuneztovari e Anopheles triannulatus davisi representaram juntas 1,4%. Os anofelinos ocorreram o ano inteiro, principalmente no período chuvoso, sendo mais freqüentes no intra (75,3% do que no peridomicílio (24,7%, preferindo sugar sangue no crepúsculo vespertino e nas primeiras horas da noite. CONCLUSÃO: As variações observadas no comportamento do anofelino mostram que as diferentes espécies vêm adaptando-se, em maior ou menor grau, ao convívio com o homem nas suas habitações.

  16. Espécies de Anopheles (Culicidae, Anophelinae em área endêmica de malária, Maranhão, Brasil

    Directory of Open Access Journals (Sweden)

    Xavier Maria M dos SP

    1999-01-01

    Full Text Available OBJETIVO: Estudar a flutuação sazonal, freqüência horária, abundância relativa e riqueza de espécies de Anopheles em ambiente antrópico, para entender a bioecologia do grupo e para a monitorização do programa de controle da malária. MÉTODOS: Os anofelinos foram estudados durante um ano, de outubro de 1996 a setembro de 1997, das 18 às 6 horas, a cada 30 dias, no Município da Raposa, Ilha de São Luís, Maranhão. Utilizou-se o método de captura de fêmeas em iscas humanas no intra e peridomicílio, com tubo de sucção e foco luminoso orientado. RESULTADOS: Foram coletados 1.407 espécimes assim distribuídos: Anopheles aquasalis (82%, Anopheles galvaoi (10,2% e Anopheles albitarsis (6,4%. As demais espécies, Anopheles evansae, Anopheles nuneztovari e Anopheles triannulatus davisi representaram juntas 1,4%. Os anofelinos ocorreram o ano inteiro, principalmente no período chuvoso, sendo mais freqüentes no intra (75,3% do que no peridomicílio (24,7%, preferindo sugar sangue no crepúsculo vespertino e nas primeiras horas da noite. CONCLUSÃO: As variações observadas no comportamento do anofelino mostram que as diferentes espécies vêm adaptando-se, em maior ou menor grau, ao convívio com o homem nas suas habitações.

  17. Antiviral immunity of Anopheles gambiae is highly compartmentalized, with distinct roles for RNA interference and gut microbiota.

    Science.gov (United States)

    Carissimo, Guillaume; Pondeville, Emilie; McFarlane, Melanie; Dietrich, Isabelle; Mitri, Christian; Bischoff, Emmanuel; Antoniewski, Christophe; Bourgouin, Catherine; Failloux, Anna-Bella; Kohl, Alain; Vernick, Kenneth D

    2015-01-13

    Arboviruses are transmitted by mosquitoes and other arthropods to humans and animals. The risk associated with these viruses is increasing worldwide, including new emergence in Europe and the Americas. Anopheline mosquitoes are vectors of human malaria but are believed to transmit one known arbovirus, o'nyong-nyong virus, whereas Aedes mosquitoes transmit many. Anopheles interactions with viruses have been little studied, and the initial antiviral response in the midgut has not been examined. Here, we determine the antiviral immune pathways of the Anopheles gambiae midgut, the initial site of viral infection after an infective blood meal. We compare them with the responses of the post-midgut systemic compartment, which is the site of the subsequent disseminated viral infection. Normal viral infection of the midgut requires bacterial flora and is inhibited by the activities of immune deficiency (Imd), JAK/STAT, and Leu-rich repeat immune factors. We show that the exogenous siRNA pathway, thought of as the canonical mosquito antiviral pathway, plays no detectable role in antiviral defense in the midgut but only protects later in the systemic compartment. These results alter the prevailing antiviral paradigm by describing distinct protective mechanisms in different body compartments and infection stages. Importantly, the presence of the midgut bacterial flora is required for full viral infectivity to Anopheles, in contrast to malaria infection, where the presence of the midgut bacterial flora is required for protection against infection. Thus, the enteric flora controls a reciprocal protection tradeoff in the vector for resistance to different human pathogens.

  18. Life-table analysis of Anopheles malaria vectors: generational mortality as tool in mosquito vector abundance and control studies

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    Godwin Ray Anugboba Okogun

    2005-06-01

    Full Text Available Background & objectives: Vector control will for sometime remain a primary weapon in the waragainst vector borne diseases. Malaria is of paramount importance in this with its associated highmorbidity and mortality especially in sub-Saharan Africa. This study on generational mortality associatedfactors in Anopheles mosquitoes life-table analysis was designed to investigate the fecundity,levels of mortality and mortality associated factors at the aquatic stages of anopheline malaria vectors.Methods: Mortality associated factors were investigated at the eggs, I and II instar larval, III and IVinstar larval and pupal stages of two anopheline species— Anopheles pseudopunctipennis (Theobaldand An. gambiae life-cycles in screen cages. Adult male and female mosquitoes were membrane filterfedand algae in culture medium formed the bulk of food substances for the larval stage. Environmentaltemperature of culture media, pH and some associated physio-chemical factors were also determined.Results: Results showed significant mortality rates at various aquatic stages. Infertility, cannibalismand environmental factors were the major factors responsible for mortality at the egg, larval and pupalstages respectively.Interpretation & conclusion: The aquatic stages of Anopheles mosquito mortality factor K and themortality factors at the various stages investigated k1, k2, k3 and k4 are discussed. Our recommendationsinclude further studies on the possible genetic modification of predacious An. pseudopunctipennislarvae and/or its modification for the production of sterile/infertile eggs as possible alternativesin the reduction and control of anopheline malaria burden.

  19. Larvicidal activity of Cymbopogon citratus (DC) Stapf. and Croton macrostachyus Del. against Anopheles arabiensis Patton, a potent malaria vector.

    Science.gov (United States)

    Karunamoorthi, K; Ilango, K

    2010-01-01

    Methanol leaf extracts of two Ethiopian traditional medicinal plants viz., Lomisar [vernacular name (local native language, Amharic); Cymbopogon citratus (DC) Stapf. (Poaceae)] and Bisana [vernacular name (local native language, Amharic); Croton macrostachyus Del. (Euphorbiaceae)] were screened for larvicidal activity against late third instar larvae of Anopheles arabiensis Patton, a potent malaria vector in Ethiopia. The larval mortality was observed 24 h of post treatment. Both plant extracts demonstrated varying degrees of larvicidal activity against Anopheles arabiensis. Cymbopogon citratus extract has exhibited potent larvicidal activity than Croton macrostachyus at lower concentrations. The LC50 and LC90 values of Cymbopogon citratus were 74.02 and 158.20 ppm, respectively. From this data, a chi-square value 2.760 is significant at the P < 0.05 level. While, the LC50 and LC90 values of Croton macrostachyus were 89.25 and 224.98 ppm, respectively and the chi-square value 1.035 is significant at the P < 0.05 level. The present investigation establishes that these plant extracts could serve as potent mosquito larvicidal agents against Anopheles arabiensis. However, their mode of actions and larvicidal efficiency under the field conditions should be scrutinized and determined in the near future.

  20. Poverty and price transmission

    DEFF Research Database (Denmark)

    Elleby, Christian

    A key parameter determining the welfare impact from a world market shock is the transmission elasticity which measures the average domestic response to an international price change. Many studies have estimated price transmission elasticities for a large number of countries but the variation in t...

  1. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  2. Espécies de Anopheles (Culicidae, Anophelinae em área endêmica de malária, Maranhão, Brasil Species of Anopheles (Culicidae, Anophelinae in a malaria-endemic area, Maranhão, Brazil

    Directory of Open Access Journals (Sweden)

    Maria M dos SP Xavier

    1999-12-01

    Full Text Available OBJETIVO: Estudar a flutuação sazonal, freqüência horária, abundância relativa e riqueza de espécies de Anopheles em ambiente antrópico, para entender a bioecologia do grupo e para a monitorização do programa de controle da malária. MÉTODOS: Os anofelinos foram estudados durante um ano, de outubro de 1996 a setembro de 1997, das 18 às 6 horas, a cada 30 dias, no Município da Raposa, Ilha de São Luís, Maranhão. Utilizou-se o método de captura de fêmeas em iscas humanas no intra e peridomicílio, com tubo de sucção e foco luminoso orientado. RESULTADOS: Foram coletados 1.407 espécimes assim distribuídos: Anopheles aquasalis (82%, Anopheles galvaoi (10,2% e Anopheles albitarsis (6,4%. As demais espécies, Anopheles evansae, Anopheles nuneztovari e Anopheles triannulatus davisi representaram juntas 1,4%. Os anofelinos ocorreram o ano inteiro, principalmente no período chuvoso, sendo mais freqüentes no intra (75,3% do que no peridomicílio (24,7%, preferindo sugar sangue no crepúsculo vespertino e nas primeiras horas da noite. CONCLUSÃO: As variações observadas no comportamento do anofelino mostram que as diferentes espécies vêm adaptando-se, em maior ou menor grau, ao convívio com o homem nas suas habitações.INTRODUCTION: The study of the seasonal fluctuation, nocturnal activity, relative abundance and the richness of Anopheles species in anthropic environment is essential to the understanding of the their bioecology and to the surveillance program of malaria control. METHODS: The Anopheles species were studied from 6 P.M. to 6 A.M., once a month, for one year, from October 1996 to September 1997, in the municipal district of Raposa, of the São Luís island, Maranhão state. The basic method was the capture of female specimens on human baits in peri and intradomicile sites by means of aspiration tube and guided luminous focus. RESULTS: A total of 1.407 specimens were collected and distributed as follow: Anopheles

  3. The use of wide-mesh gauze impregnated with lambda-cyhalothrin covering wall openings in huts as a vector control method in Suriname

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    Jaco Voorham

    1997-02-01

    Full Text Available An alternative vector control method, using lambda-cyhalothrin impregnated wide-mesh gauze covering openings in the walls of the houses was developed in an area in the Eastern part of the interior of Suriname. Experimental hut observations showed that Anopheles darlingi greatly reduced their biting activity (99-100% during the first 5 months after impregnation. A model assay showed high mortality both of mosquitoes repelled by the gauze as well as of those that succeeded in getting through it. A field application test in 270 huts showed good acceptance by the population and good durability of the applied gauze. After introducing the method in the entire working area, replacing DDT residual housespraying, the malaria prevalence, of 25-37% before application dropped and stabilized at between 5 and 10% within one year. The operational costs were less than those of the previously used DDT housespraying program, due to a 50% reduction in the cost of materials used. The method using widemesh gauze impregnated with lambdacyhalothrin strongly affects the behavior of An. darlingi. It is important to examine the effect of the method on malaria transmission further, since data indirectly obtained suggest substantial positive results.

  4. Impact of insecticide-treated materials on filaria transmission by the various species of vector mosquito in Africa.

    Science.gov (United States)

    Pedersen, E M; Mukoko, D A

    2002-12-01

    Nocturnally periodic bancroftian filariasis is maintained by three mainly endophilic vectors in East Africa: Culex quinquefasciatus, Anopheles funestus and the An. gambiae complex. Permethrin-impregnated bednets provide considerable protection against these mosquitoes, but the species respond differently. The degree of protection conferred by treated bednets was determined in Kenyan communities where all three vectors actively transmit Wuchereria bancrofti. The annual transmission potential in the communities (i.e. an estimate of the number of human infective, third-stage larvae of W. bancrofti inoculated into each villager each year) was reduced by 92%, through the nets' impact on vector biting rates (reduced by 22%) and their cumulative impact on the annual infective biting rate (reduced by 95%). Thus a modest reduction in the numbers of mosquitoes biting humans, attributable to the use of the insecticide-treated nets, strongly suppressed the risk of W. bancrofti transmission.

  5. Effect of different hosts on feeding patterns and mortality of mosquitoes (Diptera: Culicidae and their implications on parasite transmission

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    Eliningaya J Kweka

    2010-01-01

    Full Text Available Aim: The host-response to hematophagus insects is still an important parameter in understanding disease transmission patterns. We investigated the feeding and mortality rates of three mosquito species, namely Culex quinquefasciatus, Aedes aegypti and Anopheles arabiensis against three different hosts. Materials and Methods: Unfed three to five-day-old female mosquitoes were released in a tunnel box that had a rabbit or guinea pig or mice as a host. The feeding succession patterns of mosquitoes in different hosts were An. arabiensis, Cx. quinquefasciatus and A. aegypti. Results: Mosquito mortality rate was 54.9% for mosquitoes introduced in mice as a host, 34.3% in the Guinea pig and 10.8% for those that introduced in the rabbit. Conclusion: The presence of defensive and tolerable hosts in environment emphasizes the relevance of studying epidemiological impact of these behaviors in relation to diseases transmission.

  6. Interspecies transmission of prions.

    Science.gov (United States)

    Afanasieva, E G; Kushnirov, V V; Ter-Avanesyan, M D

    2011-12-01

    Mammalian prions are infectious agents of proteinaceous nature that cause several incurable neurodegenerative diseases. Interspecies transmission of prions is usually impeded or impossible. Barriers in prion transmission are caused by small interspecies differences in the primary structure of prion proteins. The barriers can also depend on the strain (variant) of a transmitted prion. Interspecies barriers were also shown for yeast prions, which define some heritable phenotypes. Yeast prions reproduce all the main traits of prion transmission barriers observed for mammals. This allowed to show that the barrier in prion transmission can be observed even upon copolymerization of two prionogenic proteins. Available data allow elucidation of the mechanisms that impede prion transmission or make it impossible.

  7. Nonlinear magnetoinductive transmission lines

    CERN Document Server

    Lazarides, Nikos; Tsironis, G P

    2011-01-01

    Power transmission in one-dimensional nonlinear magnetic metamaterials driven at one end is investigated numerically and analytically in a wide frequency range. The nonlinear magnetic metamaterials are composed of varactor-loaded split-ring resonators which are coupled magnetically through their mutual inductances, forming thus a magnetoiductive transmission line. In the linear limit, significant power transmission along the array only appears for frequencies inside the linear magnetoinductive wave band. We present analytical, closed form solutions for the magnetoinductive waves transmitting the power in this regime, and their discrete frequency dispersion. When nonlinearity is important, more frequency bands with significant power transmission along the array may appear. In the equivalent circuit picture, the nonlinear magnetoiductive transmission line driven at one end by a relatively weak electromotive force, can be modeled by coupled resistive-inductive-capacitive (RLC) circuits with voltage-dependent cap...

  8. [Myths concerning malarial transmission among Amazonian Indians and their relation with 2 types of transmission encountered in the Amazonian forest].

    Science.gov (United States)

    Molez, J F

    1999-01-01

    Among the Indians Desana's (Tukano amerindians) in the Upper Rio Negro, the interseasonal variation of the malarial fevers were associated with two myths (localised in two distinguishable places). One myth associates the malarial with the rivers which contain "malaria pots". Conception based on an observation of localised water collection in the banks and the rocky rapids ("banks and rocky's fever"). The transmission and the anophelian density present variation between the seasons in relation to the river's level. Another myth associates malarial fevers in the forest, with the song of a frog ("fever's frog") and the flowering and fructification of a tree (Poaqueira sericea Thul.). There is in South America a particular type of forest malaria, known as "Bromelia malaria" and denounced in human and/or simian transmission. This forest malaria is transmitted by the a sub-genus anopheles (Kerteszia) which larval breeding are areal in the canopy. The breeding places are found in the forest in the epiphyte bromeliads. To understand this type of transmission, we must take reference to the previous endomological data at the Upper Oyapock Wayâpi (Tupi amerindians). This Bromelia malaria could fluctuated according larval density variation, related to washing of epiphytes (end of the rainy season) or to their flowering (end of the dry season). The "fever's frog" myth collected at the Desana's in the Upper Rio Negro can be related to the existence of Bromelia malaria in this amazonian habitat. These myths showed the perfect adaptation of the amerindians to their environment and their complete knowledge of the neotropical forest.

  9. Adult anopheline ecology and malaria transmission in irrigated areas of South Punjab, Pakistan

    DEFF Research Database (Denmark)

    Herrel, N; Amerasinghe, F P; Ensink, J

    2004-01-01

    . Anopheles stephensi, An. culicifacies and An. subpictus populations peaked in August, September and October, respectively. High temperatures and low rainfall negatively affected seasonal abundance in our area. There were interesting differences in anopheline fauna between villages, with An. culicifacies......: Culicidae) could be related to malaria transmission in rural areas with intensive irrigation and a history of malaria epidemics. In this paper we present our observations from three villages located along an irrigation canal in South Punjab. The study was carried out from 1 April 1999 to 31 March 2000....... pulcherrimus Theobald (1.0%) and An. peditaeniatus Leicester (0.1%). Most mosquitoes (98.8%) were collected from indoor resting-sites whereas collections from potential resting-sites outdoors accounted for only 1.2% of total anopheline densities, confirming the endophilic behaviour of anophelines in Pakistan...

  10. Modeling the influence of local environmental factors on malaria transmission in Benin and its implications for cohort study.

    Science.gov (United States)

    Cottrell, Gilles; Kouwaye, Bienvenue; Pierrat, Charlotte; le Port, Agnès; Bouraïma, Aziz; Fonton, Noël; Hounkonnou, Mahouton Norbert; Massougbodji, Achille; Corbel, Vincent; Garcia, André

    2012-01-01

    Malaria remains endemic in tropical areas, especially in Africa. For the evaluation of new tools and to further our understanding of host-parasite interactions, knowing the environmental risk of transmission--even at a very local scale--is essential. The aim of this study was to assess how malaria transmission is influenced and can be predicted by local climatic and environmental factors.As the entomological part of a cohort study of 650 newborn babies in nine villages in the Tori Bossito district of Southern Benin between June 2007 and February 2010, human landing catches were performed to assess the density of malaria vectors and transmission intensity. Climatic factors as well as household characteristics were recorded throughout the study. Statistical correlations between Anopheles density and environmental and climatic factors were tested using a three-level Poisson mixed regression model. The results showed both temporal variations in vector density (related to season and rainfall), and spatial variations at the level of both village and house. These spatial variations could be largely explained by factors associated with the house's immediate surroundings, namely soil type, vegetation index and the proximity of a watercourse. Based on these results, a predictive regression model was developed using a leave-one-out method, to predict the spatiotemporal variability of malaria transmission in the nine villages.This study points up the importance of local environmental factors in malaria transmission and describes a model to predict the transmission risk of individual children, based on environmental and behavioral characteristics.

  11. Understanding Ebola Virus Transmission

    Directory of Open Access Journals (Sweden)

    Seth Judson

    2015-02-01

    Full Text Available An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.

  12. Tractor Transmissions. A Teaching Reference.

    Science.gov (United States)

    American Association for Agricultural Engineering and Vocational Agriculture, Athens, GA.

    The manual was developed as a reference for teaching students about transmissions in farm tractors. The manual is divided into five sections: (1) transmission history, (2) gears and bearings in transmission, (3) sliding-gear transmissions, (4) planetary gearing, and (5) glossary. The working principles of the sliding-gear transmission, the most…

  13. Transmission Cost Allocation Methodologies for Regional Transmission Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Fink, S.; Rogers, J.; Porter, K.

    2010-07-01

    This report describes transmission cost allocation methodologies for transmission projects developed to maintain or enhance reliability, to interconnect new generators, or to access new resources and enhance competitive bulk power markets, otherwise known as economic transmission projects.

  14. Insecticide resistance in Anopheles gambiae from south-western Chad, Central Africa

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    Etang Josiane

    2008-09-01

    Full Text Available Abstract Background Indoor residual spraying and insecticide-treated nets (ITN are essential components of malaria vector control in Africa. Pyrethroids are the only recommended compounds for nets treatment because they are fast-acting insecticides with low mammalian toxicity. However, there is growing concern that pyrethroid resistance may threaten the sustainability of ITN scaling-up programmes. Here, insecticide susceptibility was investigated in Anopheles gambiae sensu lato from an area of large scale ITN distribution programme in south-western Chad. Methods Susceptibility to 4% DDT, 0.05% deltamethrin, 0.75% permethrin, 0.1% bendiocarb and 5% malathion was assessed using the WHO standard procedures for adult mosquitoes. Tests were carried out with two to four days-old, non-engorged female mosquitoes. The An. gambiae Kisumu strain was used as a reference. Knockdown effect was recorded every 5 min and mortality scored 24 h after exposure. Mosquitoes were identified to species and molecular form by PCR-RFLP and genotypes at the kdr locus were determined in surviving specimens by Hot Oligonucleotide Ligation Assay (HOLA. Results During this survey, full susceptibility to malathion was recorded in all samples. Reduced susceptibility to bendiocarb (mortality rate of 96.1% was found in one sample out of nine assayed. Increased tolerance to pyrethroids was detected in most samples (8/9 with mortality rates ranging from 70.2 to 96.6% for deltamethrin and from 26.7 to 96.3% for permethrin. Pyrethroid tolerance was not associated with a significant increase of knock-down times. Anopheles arabiensis was the predominant species of the An. gambiae complex in the study area, representing 75 to 100% of the samples. Screening for kdr mutations detected the L1014F mutation in 88.6% (N = 35 of surviving An. gambiae sensu stricto S form mosquitoes. All surviving An. arabiensis (N = 49 and M form An. gambiae s.s. (N = 1 carried the susceptible allele

  15. Susceptibility of eight species members in the Anopheles hyrcanus group to nocturnally subperiodic Brugia malayi

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    Saeung Atiporn

    2013-01-01

    Full Text Available Abstract Background Filariasis, caused by Brugia malayi, is a public health problem in Thailand. Currently, at least two locations in southern Thailand are reported to be active endemic areas. Two and four Mansonia species are primary and secondary vectors, respectively, of the nocturnally subperiodic race, whereas, Coquillettidia crassipes is a vector of the diurnally subperiodic race. Although several Anopheles species have been incriminated extensively as natural and/or suspected vectors of B. malayi, little is known about vector competence between indigenous Anopheles and this filaria in Thailand. Thus, the susceptibility levels of eight species members in the Thai An. hyrcanus group to nocturnally subperiodic B. malayi are presented herein, and the two main refractory factors that affect them in different degrees of susceptibility have been elucidated. Methods Aedes togoi (a control vector, An. argyropus, An. crawfordi, An. nigerrimus, An. nitidus, An. paraliae, An. peditaeniatus, An. pursati and An. sinensis were allowed to feed artificially on blood containing B. malayi microfilariae, and dissected 14 days after feeding. To determine factors that take effect at different susceptibility levels, stain-smeared blood meals were taken from the midguts of Ae. togoi, An. peditaeniatus, An. crawfordi, An. paraliae, An. sinensis and An. nitidus immediately after feeding, and their dissected-thoraxes 4 days post blood-feedings were examined consecutively for microfilariae and L1 larvae. Results The susceptibility rates of Ae. togoi, An. peditaeniatus, An. crawfordi, An. nigerrimus, An. argyropus, An. pursati, An. sinensis, An. paraliae and An. nitidus to B. malayi were 70–95%, 70–100%, 80–85%, 50–65%, 60%, 60%, 10%, 5%, and 0%, respectively. These susceptibility rates related clearly to the degrees of normal larval development in thoracic muscles, i.e., Ae. togoi, An. peditaeniatus, An. crawfordi, An. paraliae, An. sinensis and An. nitidus

  16. Analysis of two novel midgut-specific promoters driving transgene expression in Anopheles stephensi mosquitoes.

    Directory of Open Access Journals (Sweden)

    Tony Nolan

    Full Text Available BACKGROUND: Tissue-specific promoters controlling the expression of transgenes in Anopheles mosquitoes represent a valuable tool both for studying the interaction between these malaria vectors and the Plasmodium parasites they transmit and for novel malaria control strategies based on developing Plasmodium-refractory mosquitoes by expressing anti-parasitic genes. With this aim we have studied the promoter regions of two genes from the most important malaria vector, Anopheles gambiae, whose expression is strongly induced upon blood feeding. RESULTS: We analysed the A. gambiae Antryp1 and G12 genes, which we have shown to be midgut-specific and maximally expressed at 24 hours post-bloodmeal (PBM. Antryp1, required for bloodmeal digestion, encodes one member of a family of 7 trypsin genes. The G12 gene, of unknown function, was previously identified in our laboratory in a screen for genes induced in response to a bloodmeal. We fused 1.1 kb of the upstream regions containing the putative promoter of these genes to reporter genes and transformed these into the Indian malaria vector A. stephensi to see if we could recapitulate the expression pattern of the endogenous genes. Both the Antryp1 and G12 upstream regions were able to drive female-predominant, midgut-specific expression in transgenic mosquitoes. Expression of the Antryp1-driven reporter in transgenic A. stephensi lines was low, undetectable by northern blot analysis, and failed to fully match the induction kinetics of the endogenous Antryp1 gene in A. gambiae. This incomplete conservation of expression suggests either subtle differences in the transcriptional machinery between A. stephensi and A. gambiae or that the upstream region chosen lacked all the control elements. In contrast, the G12 upstream region was able to faithfully reproduce the expression profile of the endogenous A. gambiae gene, showing female midgut specificity in the adult mosquito and massive induction PBM, peaking at 24

  17. Effect of discriminative plant-sugar feeding on the survival and fecundity of Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Jackson Robert R

    2007-08-01

    Full Text Available Abstract Background A previous study showed for Anopheles gambiae s.s. a gradation of feeding preference on common plant species growing in a malaria holoendemic area in western Kenya. The present follow-up study determines whether there is a relationship between the mosquito's preferences and its survival and fecundity. Methods Groups of mosquitoes were separately given ad libitum opportunity to feed on five of the more preferred plant species (Hamelia patens, Parthenium hysterophorus, Ricinus communis, Senna didymobotrya, and Tecoma stans and one of the less preferred species (Lantana camara. The mosquitoes were monitored daily for survival. Sugar solution (glucose 6% and water were used as controls. In addition, the fecundity of mosquitoes on each plant after (i only one blood meal (number of eggs oviposited, and (ii after three consecutive blood meals (proportion of females ovipositing, number of eggs oviposited and hatchability of eggs, was determined. The composition and concentration of sugar in the fed-on parts of each plant species were determined using gas chromatography. Using SAS statistical package, tests for significant difference of the fitness values between mosquitoes exposed to different plant species were conducted. Results and Conclusion Anopheles gambiae that had fed on four of the five more preferred plant species (T. stans, S. didymobotrya, R. communis and H. patens, but not P. hysterophorus lived longer and laid more eggs after one blood meal, when compared with An. gambiae that had fed on the least preferred plant species L. camara. When given three consecutive blood-meals, the percentage of females that oviposited, but not the number of eggs laid, was significantly higher for mosquitoes that had previously fed on the four more preferred plant species. Total sugar concentration in the preferred plant parts was significantly correlated with survival and with the proportion of females that laid eggs. This effect was

  18. The role of cow urine in the oviposition site preference of culicine and Anopheles mosquitoes

    Directory of Open Access Journals (Sweden)

    Kweka Eliningaya J

    2011-09-01

    Full Text Available Abstract Background Chemical and behavioural ecology of mosquitoes plays an important role in the development of chemical cue based vector control. To date, studies available have focused on evaluating mosquito attractants and repellents of synthetic and human origins. This study, however, was aimed at seasonal evaluation of the efficiency of cow urine in producing oviposition cues to Anopheles gambiae s.l. and Culex quinquefasciatus in both laboratory and field conditions. Methods Oviposition response evaluation in laboratory conditions was carried out in mosquito rearing cages. The oviposition substrates were located in parallel or in diagonal positions inside the cage. Urine evaluation against gravid females of An. arabiensis and Cx. quinquefasciatus was carried out at Day 1, Day 3 and Day 7. Five millilitres (mls of cow urine was added to oviposition substrate while de-chlorinated water was used as a control. In field experiments, 500 mls of cow urine was added in artificial habitats with 2500 mls of de-chlorinated water and 2 kgs of soil. The experiment was monitored for thirty consecutive days, eggs were collected daily from the habitats at 7.00 hrs. Data analysis was performed using parametric and non-parametric tests for treatments and controls while attraction of the oviposition substrate in each species was presented using Oviposition Activity Index (OAI. Results The OAI was positive with ageing of cattle urine in culicine species in both laboratory and field experiments. The OAI for anopheline species was positive with fresh urine. The OAI during the rainy season was positive for all species tested while in the dry season the OAI for culicine spp and Anopheles gambiae s.l., changed with time from positive to negative values. Based on linear model analysis, seasons and treatments had a significant effect on the number of eggs laid in habitats, even though the number of days had no effect. Conclusion Oviposition substrates treated with

  19. Transmissions in vehicles 2010

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Within the international VDI congress 'Gears in vehicles 2010' of the VDI Wissensforum GmbH (Duesseldorf, Federal Republic of Germany) between 22nd and 23rd June, 2010, in Friedrichshafen (Federal Republic of Germany), the following lectures were held: (1) 8HP70H - The moldhybrid transmission from ZF - Cjallenges and achievements (P. Gutmann); (2) GETRAG boosted range extender - A highly flexible electric powertrain for maximum CO{sub 2} reduction (S. Huepkes); (3) E-Transmission between full-hybrid and E-drive (P. Tenberge); (4) Reducing NO{sub x} and particulate emissions in electrified drivelines (R. Kuberczyk); (5) Simulation aided HEV and EV development: from the component to the whole powertrain (A. Gacometti); (6) Investigations on operating behaviour of the optimized CVT hybrid driveline (B.-R. Hoehn); (7) Customer-oriented dimensioning of electrified drivetrains (M. Eghtessad); (8) Decentralized optimal control strategy for parallel hybrid electric vehicles (A. Frenkel); (9) The new generation 6-speed automatic transmission AF40 (G. Bednarek); (10) Customized mechatronic solutions for integrated transmission control units (M. Wieczorek); (11) The optimal automatic transmission for front-transverse applications - Planetary transmissions or dual clutch transmissions? (G. Gumpoltsberger); (12) The new shift-by-wire gearshift lever for the Audi A8 - Requirements and concept (T. Guttenbergere); (13) The new shift-by-wire gearshift lever for the Audi A8 - Realization (A. Giefer); (14) Fuel-efficient transmissions of the future: Calculation of the efficiency factor for vehicle transmissions (B. Volpert); (15) HT-ACM: A new polymer generation for static and dynamic gearbox sealing solutions (E. Osen); (16) 'Energy efficiency equipped solutions by SKF' for power train applications - A contribution to CO{sub 2} - emission reduction and sustainability (T. Bobke); (17) 6-Ratio planetary shift transmission controlled by 4 external brakes, and design

  20. Watching Handball Transmissions

    DEFF Research Database (Denmark)

    Frandsen, Kirsten

    2010-01-01

    , due to the dramaturgic structure of handball transmissions, viewers consider such transmissions particularly reliable and effective sources of entertainment. The transmissions’ entertainment value derives from their specific ability to give the viewers a complex experience of feeling autonomous...... and competent when mastering the game and in relation to others. The study shows that entertainment concerns both affective involvement and identity formation, as social and cultural meaning seem to be at the root of involvement. Even though both men and women find great joy in the transmissions, their viewing...... is embedded in quite diverse patterns regarding additional media use. This points to gendered differences regarding how the entertaining experience is basically received and the qualities sought and pursued in the transmissions....

  1. Down hole transmission system

    Science.gov (United States)

    Hall, David R.; Hall, Jr., H. Tracy

    2007-07-24

    A transmission system in a downhole component comprises a data transmission element in both ends of the downhole component. Each data transmission element houses an electrically conducting coil in a MCEI circular trough. The electrically conducting coil comprises at least two generally fractional loops. In the preferred embodiment, the transmission elements are connected by an electrical conductor. Preferably, the electrical conductor is a coaxial cable. Preferably, the MCEI trough comprises ferrite. In the preferred embodiment, the fractional loops are connected by a connecting cable. In one aspect of the present invention, the connecting cable is a pair of twisted wires. In one embodiment the connecting cable is a shielded pair of twisted wires. In another aspect of the present invention, the connecting cable is a coaxial cable. The connecting cable may be disposed outside of the MCEI circular trough.

  2. Transmission of Mumps

    Science.gov (United States)

    ... Serology Publications and Resources Multimedia MMWR Articles Outbreak Articles Related Links World Health Organization Medline Plus Transmission of Mumps Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir ...

  3. Kansas Electric Transmission Lines

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital representation of the EletcircTransmission lines for the State of Kansas as maintained by the Kansas Corporation Commission. Data is...

  4. Eliminating Perinatal HIV Transmission

    Centers for Disease Control (CDC) Podcasts

    2012-11-26

    In this podcast, CDC’s Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students.  Created: 11/26/2012 by Division of HIV/AIDS Prevention.   Date Released: 11/26/2012.

  5. Using remote sensing to map larval and adult populations of Anopheles hyrcanus (Diptera: Culicidae a potential malaria vector in Southern France

    Directory of Open Access Journals (Sweden)

    Roger François

    2008-02-01

    Full Text Available Abstract Background Although malaria disappeared from southern France more than 60 years ago, suspicions of recent autochthonous transmission in the French Mediterranean coast support the idea that the area could still be subject to malaria transmission. The main potential vector of malaria in the Camargue area, the largest river delta in southern France, is the mosquito Anopheles hyrcanus (Diptera: Culicidae. In the context of recent climatic and landscape changes, the evaluation of the risk of emergence or re-emergence of such a major disease is of great importance in Europe. When assessing the risk of emergence of vector-borne diseases, it is crucial to be able to characterize the arthropod vector's spatial distribution. Given that remote sensing techniques can describe some of the environmental parameters which drive this distribution, satellite imagery or aerial photographs could be used for vector mapping. Results In this study, we propose a method to map larval and adult populations of An. hyrcanus based on environmental indices derived from high spatial resolution imagery. The analysis of the link between entomological field data on An. hyrcanus larvae and environmental indices (biotopes, distance to the nearest main productive breeding sites of this species i.e., rice fields led to the definition of a larval index, defined as the probability of observing An. hyrcanus larvae in a given site at least once over a year. Independent accuracy assessments showed a good agreement between observed and predicted values (sensitivity and specificity of the logistic regression model being 0.76 and 0.78, respectively. An adult index was derived from the larval index by averaging the larval index within a buffer around the trap location. This index was highly correlated with observed adult abundance values (Pearson r = 0.97, p An. hyrcanus larval and adult populations from the landscape indices. Conclusion This work shows that it is possible to use

  6. 77 FR 6554 - Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke-American Transmission...

    Science.gov (United States)

    2012-02-08

    ... Energy Regulatory Commission Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke... (Commission), 18 CFR 381.302, Zephyr Power Transmission, LLC (Zephyr), Pathfinder Power Transmission, LLC (PPT... to exercise its negotiated rate authority for Zephyr Power Transmission Project; (2) that...

  7. National transmission grid study

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Spencer [USDOE Office of the Secretary of Energy, Washington, DC (United States)

    2003-05-31

    The National Energy Policy Plan directed the U.S. Department of Energy (DOE) to conduct a study to examine the benefits of establishing a national electricity transmission grid and to identify transmission bottlenecks and measures to address them. DOE began by conducting an independent analysis of U.S. electricity markets and identifying transmission system bottlenecks using DOE’s Policy Office Electricity Modeling System (POEMS). DOE’s analysis, presented in Section 2, confirms the central role of the nation’s transmission system in lowering costs to consumers through increased trade. More importantly, DOE’s analysis also confirms the results of previous studies, which show that transmission bottlenecks and related transmission system market practices are adding hundreds of millions of dollars to consumers’ electricity bills each year. A more detailed technical overview of the use of POEMS is provided in Appendix A. DOE led an extensive, open, public input process and heard a wide range of comments and recommendations that have all been considered.1 More than 150 participants registered for three public workshops held in Detroit, MI (September 24, 2001); Atlanta, GA (September 26, 2001); and Phoenix, AZ (September 28, 2001).

  8. Larvicidal potential of essential oils against Musca domestica and Anopheles stephensi.

    Science.gov (United States)

    Chauhan, Nitin; Malik, Anushree; Sharma, Satyawati; Dhiman, R C

    2016-06-01

    The larvicidal activity of Mentha piperita, Cymbopogan citratus (lemongrass), Eucalyptus globulus and Citrus sinensis (orange) essential oils and their combinations was evaluated against Musca domestica (housefly) and Anopheles stephensi (mosquitoes) through contact toxicity assay. Among all the tested essential oils/combinations, Me. piperita was found to be the most effective larvicidal agent against Mu. domestica and An. stephensi with LC50 values of 0.66 μl/cm(2) and 44.66 ppm, respectively, after 48 h. The results clearly highlighted that the addition of mentha oil to other oils (1:1 ratio) improved their larvicidal activity. The order of effectiveness of essential oils/combinations indicated that the pattern for An. stephensi follows the trend as mentha > mentha + lemongrass > lemongrass > mentha + eucalyptus > eucalyptus > mentha + orange > orange and for Mu. domestica as mentha > mentha + lemongrass > lemongrass > mentha + orange > orange > mentha + eucalyptus > eucalyptus. The images obtained from scanning electron microscopy (SEM) analysis indicated the toxic effect of Me. piperita as the treated larvae were observed to be dehydrated and deformed. This study demonstrates the effectiveness of tested essential oils/combinations against the larval stages of Mu. domestica and An. stephensi and has the potential for development of botanical formulations.

  9. Mass Spectrometry Based Proteomic Analysis of Salivary Glands of Urban Malaria Vector Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    Sonam Vijay

    2014-01-01

    Full Text Available Salivary gland proteins of Anopheles mosquitoes offer attractive targets to understand interactions with sporozoites, blood feeding behavior, homeostasis, and immunological evaluation of malaria vectors and parasite interactions. To date limited studies have been carried out to elucidate salivary proteins of An. stephensi salivary glands. The aim of the present study was to provide detailed analytical attributives of functional salivary gland proteins of urban malaria vector An. stephensi. A proteomic approach combining one-dimensional electrophoresis (1DE, ion trap liquid chromatography mass spectrometry (LC/MS/MS, and computational bioinformatic analysis was adopted to provide the first direct insight into identification and functional characterization of known salivary proteins and novel salivary proteins of An. stephensi. Computational studies by online servers, namely, MASCOT and OMSSA algorithms, identified a total of 36 known salivary proteins and 123 novel proteins analysed by LC/MS/MS. This first report describes a baseline proteomic catalogue of 159 salivary proteins belonging to various categories of signal transduction, regulation of blood coagulation cascade, and various immune and energy pathways of An. stephensi sialotranscriptome by mass spectrometry. Our results may serve as basis to provide a putative functional role of proteins in concept of blood feeding, biting behavior, and other aspects of vector-parasite host interactions for parasite development in anopheline mosquitoes.

  10. Metabolic and target-site mechanisms combine to confer strong DDT resistance in Anopheles gambiae.

    Science.gov (United States)

    Mitchell, Sara N; Rigden, Daniel J; Dowd, Andrew J; Lu, Fang; Wilding, Craig S; Weetman, David; Dadzie, Samuel; Jenkins, Adam M; Regna, Kimberly; Boko, Pelagie; Djogbenou, Luc; Muskavitch, Marc A T; Ranson, Hilary; Paine, Mark J I; Mayans, Olga; Donnelly, Martin J

    2014-01-01

    The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms) and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible strains of An. gambiae, revealed a non-synonymous polymorphism (I114T), proximal to the DDT binding domain, which segregated with strain phenotype. Recombinant protein expression and DDT metabolism analysis revealed that the proteins from the susceptible strain lost activity at higher DDT concentrations, characteristic of substrate inhibition. The effect of I114T on GSTE2 protein structure was explored through X-ray crystallography. The amino acid exchange in the DDT-resistant strain introduced a hydroxyl group nearby the hydrophobic DDT-binding region. The exchange does not result in structural alterations but is predicted to facilitate local dynamics and enzyme activity. Expression of both wild-type and 114T alleles the allele in Drosophila conferred an increase in DDT tolerance. The 114T mutation was significantly associated with DDT resistance in wild caught M-form populations and acts in concert with target-site mutations in the voltage gated sodium channel (Vgsc-1575Y and Vgsc-1014F) to confer extreme levels of DDT resistance in wild caught An. gambiae.

  11. Genome-Wide Divergence in the West-African Malaria Vector Anopheles melas

    Directory of Open Access Journals (Sweden)

    Kevin C. Deitz

    2016-09-01

    Full Text Available Anopheles melas is a member of the recently diverged An. gambiae species complex, a model for speciation studies, and is a locally important malaria vector along the West-African coast where it breeds in brackish water. A recent population genetic study of An. melas revealed species-level genetic differentiation between three population clusters. An. melas West extends from The Gambia to the village of Tiko, Cameroon. The other mainland cluster, An. melas South, extends from the southern Cameroonian village of Ipono to Angola. Bioko Island, Equatorial Guinea An. melas populations are genetically isolated from mainland populations. To examine how genetic differentiation between these An. melas forms is distributed across their genomes, we conducted a genome-wide analysis of genetic differentiation and selection using whole genome sequencing data of pooled individuals (Pool-seq from a representative population of each cluster. The An. melas forms exhibit high levels of genetic differentiation throughout their genomes, including the presence of numerous fixed differences between clusters. Although the level of divergence between the clusters is on a par with that of other species within the An. gambiae complex, patterns of genome-wide divergence and diversity do not provide evidence for the presence of pre- and/or postmating isolating mechanisms in the form of speciation islands. These results are consistent with an allopatric divergence process with little or no introgression.

  12. Avoidance Behavior to Essential Oils by Anopheles minimus, a Malaria Vector in Thailand.

    Science.gov (United States)

    Nararak, Jirod; Sathantriphop, Sunaiyana; Chauhan, Kamal; Tantakom, Siripun; Eiden, Amanda L; Chareonviriyaphap, Theeraphap

    2016-03-01

    Essential oils extracted from 4 different plant species--citronella (Cymbopogon nardus), hairy basil (Ocimum americanum), sweet basil (Ocimum basilicum), and vetiver (Vetiveria zizanioides)-were investigated for their irritant and repellent activities against Anopheles minimus, using an excito-repellency test system. Pure essential oils were used in absolute ethanol at the concentrations of 0.5%, 1%, 2.5%, and 5% (v/v) compared with deet. At the lowest concentration of 0.5%, hairy basil displayed the best irritant and repellent effects against An. minimus. Citronella and vetiver at 1-5% showed strong irritant effects with>80% escape, while repellent effects of both oils were observed at 1% and 2.5% citronella (73-89% escape) and at 5% vetiver (83.9% escape). Sweet basil had only moderate irritant action at 5% concentration (69.6% escape) and slightly repellent on test mosquitoes (<50% escape). The results found that hairy basil, citronella, and vetiver are promising potential mosquito repellent products for protection against An. minimus.

  13. Isoenzymatic analysis of four Anopheles (Kerteszia) bellator Dyar & Knab (Diptera: Culicidae) populations.

    Science.gov (United States)

    de Carvalho-Pinto, Carlos José; Lourenço-de-Oliveira, Ricardo

    2003-12-01

    Anopheles bellator is a small silvatic bromelia-breeding mosquito and is a primary human malaria vector species in Southern Brazil. The bromelia-breeding habitat of the species should accompany the Atlantic forest coastal distribution, where bromeliads are abundant. Nonetheless, records on An. bellator collections show a gap in the species geographical distribution. An. bellator has been recorded in Southern Brazil and in the Brazilian states of Bahia and Paraíba. It appears again in the island of Trinidad, in Trinidad and Tobago. The aim of this work was to measure gene flow between different populations of An. bellator collected in the northern and southern extremes of the geographic distribution of this species. Mosquitoes were captured in forest borders in Santa Catarina, São Paulo, and Bahia states in Brazil and in the island of Trinidad in Republic of Trinidad and Tobago. Genetic distances varied between 0.076 and 0.680, based on enzymatic profiles from 11 distinct isoenzymes. Results indicate the existence of low-level gene flow between Brazilian populations of An. bellator, and a gene flow was even lower between the Brazilian and the Trinidad populations. This finding lead us to hypothesize that An. bellator did not spread along the coast, but reached northeastern areas through inland routes.

  14. [Anopheles cruzii larvae found in bromelias in an urban area on the Brazilian coast].

    Science.gov (United States)

    Marques, Gisela R A M; Forattini, Oswaldo Paulo

    2009-04-01

    The occurrence of Anopheles (Kerteszia) cruzii larvae is reported for the first time in bromelias on the ground located in an urban area within the municipality of Ilha Bela, on the northern coast of the State of São Paulo. From March 1998 to July 1999 312 immature forms of An. cruzii were captured, being that 8.6% of them were in bromelias in the urban environment, 40.1% in periurban bromelias and 51.3% in the forest. The average number of bromelias containing An. cruzii was 4.0% of the total investigated. The positive rate in the periurban and forested environments presented similar values. The presence of An. cruzii is probably due to their having been present previously in the forest, together with the frequent presence of these breeding places, food sources and appropriate shelter in the urban area. This set of factors makes it necessary to warn against the possibility of transferring infections from one environment to the other.

  15. Isoenzymatic analysis of four Anopheles (Kerteszia bellator Dyar & Knab (Diptera: Culicidae populations

    Directory of Open Access Journals (Sweden)

    Carvalho-Pinto Carlos José de

    2003-01-01

    Full Text Available Anopheles bellator is a small silvatic bromelia-breeding mosquito and is a primary human malaria vector species in Southern Brazil. The bromelia-breeding habitat of the species should accompany the Atlantic forest coastal distribution, where bromeliads are abundant. Nonetheless, records on An. bellator collections show a gap in the species geographical distribution. An. bellator has been recorded in Southern Brazil and in the Brazilian states of Bahia and Paraíba. It appers again in the island of Trinidad, in Trinidad and Tobago. The aim of this work was to measure gene flow between different populations of An. bellator collected in the northern and southern extremes of the geographic distribution of this species. Mosquitoes were captured in forest borders in Santa Catarina, São Paulo, and Bahia states in Brazil and in the island of Trinidad in Republic of Trinidad and Tobago. Genetic distances varied between 0.076 and 0.680, based on enzymatic profiles from 11 distinct isoenzymes. Results indicate the existence of low-level gene flow between Brazilian populations of An. bellator, and a gene flow was even lower between the Brazilian and the Trinidad populations. This finding lead us to hypothesize that An. bellator did not spread along the coast, but reached northeastern areas through inland routes.

  16. Authentication scheme for routine verification of genetically similar laboratory colonies: a trial with Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Sutcliffe Alice C

    2009-10-01

    Full Text Available Abstract Background When rearing morphologically indistinguishable laboratory strains concurrently, the threat of unintentional genetic contamination is constant. Avoidance of accidental mixing of strains is difficult due to the use of common equipment, technician error, or the possibility of self relocation by adult mosquitoes ("free fliers". In many cases, laboratory strains are difficult to distinguish because of morphological and genetic similarity, especially when laboratory colonies are isolates of certain traits from the same parental strain, such as eye color mutants, individuals with certain chromosomal arrangements or high levels of insecticide resistance. Thus, proving genetic integrity could seem incredibly time-consuming or impossible. On the other hand, lacking proof of genetically isolated laboratory strains could question the validity of research results. Results We present a method for establishing authentication matrices to routinely distinguish and confirm that laboratory strains have not become physically or genetically mixed through contamination events in the laboratory. We show a specific example with application to Anopheles gambiae sensu stricto strains at the Malaria Research and Reference Reagent Resource Center. This authentication matrix is essentially a series of tests yielding a strain-specific combination of results. Conclusion These matrix-based methodologies are useful for several mosquito and insect populations but must be specifically tailored and altered for each laboratory based on the potential contaminants available at any given time. The desired resulting authentication plan would utilize the least amount of routine effort possible while ensuring the integrity of the strains.

  17. Innexin AGAP001476 is critical for mediating anti-Plasmodium responses in Anopheles mosquitoes.

    Science.gov (United States)

    Li, Michelle W M; Wang, Jiuling; Zhao, Yang O; Fikrig, Erol

    2014-09-05

    The Toll and IMD pathways are known to be induced upon Plasmodium berghei and Plasmodium falciparum infection, respectively. It is unclear how Plasmodium or other pathogens in the blood meal and their invasion of the midgut epithelium would trigger the innate immune responses in immune cells, in particular hemocytes. Gap junctions, which can mediate both cell-to-cell and cell-to-extracellular communication, may participate in this signal transduction. This study examined whether innexins, gap junction proteins in insects, are involved in anti-Plasmodium responses in Anopheles gambiae. Inhibitor studies using carbenoxolone indicated that blocking innexons resulted in an increase in Plasmodium oocyst number and infection prevalence. This was accompanied by a decline in TEP1 levels in carbenoxolone-treated mosquitoes. Innexin AGAP001476 mRNA levels in midguts were induced during Plasmodium infection and a knockdown of AGAP001476, but not AGAP006241, caused an induction in oocyst number. Silencing AGAP001476 caused a concurrent increase in vitellogenin levels, a TEP1 inhibitor, in addition to a reduced level of TEP1-LRIM1-APL1C complex in hemolymph. Both vitellogenin and TEP1 are regulated by Cactus under the Toll pathway. Simultaneous knockdown of cactus and AGAP001476 failed to reverse the near refractoriness induced by the knockdown of cactus, suggesting that the AGAP001476-mediated anti-Plasmodium response is Cactus-dependent. These data demonstrate a critical role for innexin AGAP001476 in mediating innate immune responses against Plasmodium through Toll pathway in mosquitoes.

  18. Essential oils enhance the toxicity of permethrin against Aedes aegypti and Anopheles gambiae.

    Science.gov (United States)

    Gross, A D; Norris, E J; Kimber, M J; Bartholomay, L C; Coats, J R

    2017-03-01

    Insecticide resistance and growing public concern over the safety and environmental impacts of some conventional insecticides have resulted in the need to discover alternative control tools. Naturally occurring botanically-based compounds are of increased interest to aid in the management of mosquitoes. Susceptible strains of Aedes aegypti (Linnaeus) (Diptera: Culicidae) and Anopheles gambiae (Meigen) (Diptera: Culicidae) were treated with permethrin, a common type-I synthetic pyrethroid, using a discriminate dose that resulted in less than 50% mortality. Piperonyl butoxide (PBO) and 35 essential oils were co-delivered with permethrin at two doses (2 and 10 µg) to determine if they could enhance the 1-h knockdown and the 24-h mortality of permethrin. Several of the tested essential oils enhanced the efficacy of permethrin equally and more effectively than piperonyl butoxide PBO, which is the commercial standard to synergize chemical insecticide like pyrethroids. PBO had a strikingly negative effect on the 1-h knockdown of permethrin against Ae. aegypti, which was not observed in An. gambiae. Botanical essential oils have the capability of increasing the efficacy of permethrin allowing for a natural alternative to classic chemical synergists, like PBO.

  19. Sexual transfer of the steroid hormone 20E induces the postmating switch in Anopheles gambiae

    Science.gov (United States)

    Gabrieli, Paolo; Kakani, Evdoxia G.; Mitchell, Sara N.; Mameli, Enzo; Want, Elizabeth J.; Mariezcurrena Anton, Ainhoa; Serrao, Aurelio; Baldini, Francesco; Catteruccia, Flaminia

    2014-01-01

    Female insects generally mate multiple times during their lives. A notable exception is the female malaria mosquito Anopheles gambiae, which after sex loses her susceptibility to further copulation. Sex in this species also renders females competent to lay eggs developed after blood feeding. Despite intense research efforts, the identity of the molecular triggers that cause the postmating switch in females, inducing a permanent refractoriness to further mating and triggering egg-laying, remains elusive. Here we show that the male-transferred steroid hormone 20-hydroxyecdysone (20E) is a key regulator of monandry and oviposition in An. gambiae. When sexual transfer of 20E is impaired by partial inactivation of the hormone and inhibition of its biosynthesis in males, oviposition and refractoriness to further mating in the female are strongly reduced. Conversely, mimicking sexual delivery by injecting 20E into virgin females switches them to an artificial mated status, triggering egg-laying and reducing susceptibility to copulation. Sexual transfer of 20E appears to incapacitate females physically from receiving seminal fluids by a second male. Comparative analysis of microarray data from females after mating and after 20E treatment indicates that 20E-regulated molecular pathways likely are implicated in the postmating switch, including cytoskeleton and musculature-associated genes that may render the atrium impenetrable to additional mates. By revealing signals and pathways shaping key processes in the An. gambiae reproductive biology, our data offer new opportunities for the control of natural populations of malaria vectors. PMID:25368171

  20. Characterization of Anopheles gambiae Transglutaminase 3 (AgTG3) and Its Native Substrate Plugin*

    Science.gov (United States)

    Le, Binh V.; Nguyen, Jennifer B.; Logarajah, Shankar; Wang, Bo; Marcus, Jacob; Williams, Hazel P.; Catteruccia, Flaminia; Baxter, Richard H. G.

    2013-01-01

    Male Anopheles mosquitoes coagulate their seminal fluids via cross-linking of a substrate, called Plugin, by the seminal transglutaminase AgTG3. Formation of the “mating plug” by cross-linking Plugin is necessary for efficient sperm storage by females. AgTG3 has a similar degree of sequence identity (∼30%) to both human Factor XIII (FXIII) and tissue transglutaminase 2 (hTG2). Here we report the solution structure and in vitro activity for the cross-linking reaction of AgTG3 and Plugin. AgTG3 is a dimer in solution and exhibits Ca2+-dependent nonproteolytic activation analogous to cytoplasmic FXIII. The C-terminal domain of Plugin is predominantly α-helical with extended tertiary structure and oligomerizes in solution. The specific activity of AgTG3 was measured as 4.25 × 10−2 units mg−1. AgTG3 is less active than hTG2 assayed using the general substrate TVQQEL but has 8–10× higher relative activity when Plugin is the substrate. Mass spectrometric analysis of cross-linked Plugin detects specific peptides including a predicted consensus motif for cross-linking by AgTG3. These results support the development of AgTG3 inhibitors as specific and effective chemosterilants for A. gambiae. PMID:23288850

  1. HOUSE—SCALE TRIALS OF ALPHAMETHRIN (OMS—3004 AGAINST DDT RESISTANT ANOPHELES ACONITUS IN CENTRAL JAVA

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    Barodji Barodji

    2012-09-01

    Full Text Available Uji coba racun serangga alphamethrin (OMS—3004 tingkat perumahan (Stage IV telah dilakukan untuk menanggulangi vektor malaria Anopheles aconitus di desa Kaligading, Kecamatan Boja, Jawa Tengah. Alphamethrin 5 % disemprotkan pada permukaan dinding dengan dosis 100 mg/m2 dan 200 mg/m2. Penilaian entomologi dilakukan dengan cara pengujian hayati kontak langsung, kontak tidak langsung dan penangkapan An. aconitus di kandang pagi hari. An. aconitus penuh darah hasil penangkapan dipelihara selama 24 jam untuk diperiksa kematiannya. Hasil pengujian hayati kontak langsung menunjukkan bahwa umur residu racun serangga alphamethrin adalah cukup baik pada permukaan bambu maupun kayu. Umur residu yang^efek-tip (kematian > 70 % adalah selama 25 minggu setelah penyemprotan dosis 100 mg/m dan selama 29 minggu setelah penyemprotan 200 mg/m2. Efek fumigasi racun serangga alphamethrin adalah sangat lemah baik pada penyemprotan dosis 100 mg/m2 maupun pada 200 mg/m2. Kema­tian An. aconitus hanya sebesar 2 % pada 4 hari setelah penyemprotan dosis 100 mg/m2 dan 4 % pada 4 hari setelah penyemprotan 200 mg/m2.

  2. Functional characterization of PGRP-LC1 of Anopheles gambiae through deletion and RNA interference

    Institute of Scientific and Technical Information of China (English)

    Yang Chen; Erjun Ling; Zhihui Weng

    2009-01-01

    Peptidoglycan recognition proteins (PGRP) play an important role in innate immunity in insects through the activation of the Imd pathway, which has been shown to be required in the antibacterial response in insects and in the limitation of the number of Plasmodium berghei oocysts developing in mosquito midgut. The LC1gene of the PRGP family in Anopheles gambiae produces many products through alternative splicing. In this work, we demonstrate that PGRP-LC1a alone is sufficient to activate the Imd pathway in the A. gambiae L3-5 cell line through a combination of terminal or internal deletions, and RNA interference against endogenous PGRP-LC products. In the absence of endogenous PGRP-LC proteins, the integrity of the cytoplasmic domain is necessary for LC1 a function, while that of the extracellular domain is not. Moreover, the shorter the extracellular domain, the higher the activity for LC1a. However, the removal of either the cytoplasmic or the extracellular PGRP-binding domain has little impact on the activity of LC1a in the presence of endogenous PGRP-LC proteins.

  3. Larvicidal activity of essential oil and methanol extract of Nepeta menthoides against malaria vector Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Khanavi Mahnaz; Fallah Alireza; Vatandoost Hassan; Sedaghat Mahdi; Abai Mohammad Reza; Hadjiakhoondi Abbas

    2012-01-01

    Objective: To investigate the larvicidal activity of essential oil and methanol extract of theNepeta menthoides (N. menthoides) against main malaria vector, Anopheles stephensi (An. stephensi). Methods: The essential oil of plant was obtained by Clevenger type apparatus and the methanol extract was supplied with Percolation method. Larvicidal activity was tested by WHO method. Twenty five fourth-instar larvae of An. stephensi were used in the larvicidal assay and four replicates were tested for each concentration. Five different concentrations of the oil and extract were tested for calculation of LC50 and LC90 values. Results: The LC50 and LC90 values were determined by probit analysis. LC50 was 69.5 and 234.3 ppm and LC90 was 175.5 and 419.9 ppm for the extract and essential oil respectively. Conclusions: According to the results of this study methanolic extract of plant exhibited more larvicidal activity than essential oil. This could be useful for investigation of new natural larvicidal compounds.

  4. The spatial distribution of Anopheles gambiae sensu stricto and An. arabiensis (Diptera: Culicidae in Mali

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    N. Sogoba

    2007-05-01

    Full Text Available Variations in the biology and ecology and the high level of genetic polymorphism of malaria vectors in Africa highlight the value of mapping their spatial distribution to enhance successful implementation of integrated vector management. The objective of this study was to collate data on the relative frequencies of Anopheles gambiae s.s. and An. arabiensis mosquitoes in Mali, to assess their association with climate and environmental covariates, and to produce maps of their spatial distribution. Bayesian geostatistical logistic regression models were fitted to identify environmental determinants of the relative frequencies of An. gambiae s.s. and An. arabiensis species and to produce smooth maps of their geographical distribution. The frequency of An. arabiensis was positively associated with the normalized difference vegetation index, the soil water storage index, the maximum temperature and the distance to water bodies. It was negatively associated with the minimum temperature and rainfall. The predicted map suggests that, in West Africa, An. arabiensis is concentrated in the drier savannah areas, while An. gambiae s.s. prefers the southern savannah and land along the rivers, particularly the inner delta of Niger. Because the insecticide knockdown resistance (kdr gene is reported only in An. gambiae s.s. in Mali, the maps provide valuable information for vector control. They may also be useful for planning future implementation of malaria control by genetically manipulated mosquitoes.

  5. Thorsellia anophelis is the dominant bacterium in a Kenyan population of adult Anopheles gambiae mosquitoes.

    Science.gov (United States)

    Briones, Aurelio M; Shililu, Josephat; Githure, John; Novak, Robert; Raskin, Lutgarde

    2008-01-01

    Anopheles gambiae mosquitoes are not known to harbor endosymbiotic bacteria. Here we show, using nucleic acid-based methods, that 16S rRNA gene sequences specific to a recently described mosquito midgut bacterium, Thorsellia anophelis, is predominant in the midgut of adult An. gambiae s.l. mosquitoes captured in residences in central Kenya, and also occurs in the aquatic rice paddy environment nearby. PCR consistently detected T. anophelis in the surface microlayer of rice paddies, which is also consistent with the surface-feeding behavior of A. gambiae s.l. larvae. Phylogenetic analysis of cloned environmental 16S rRNA genes identified four major Thorsellia lineages, which are closely affiliated to an insect endosymbiont of the genus Arsenophonus. Physiological characterizations support the hypothesis that T. anophelis is well adapted to the female anopheline midgut by utilizing blood and tolerating the alkaline conditions in this environment. The results suggest that aquatically derived bacteria such as T. anophelis can persist through mosquito metamorphosis and become well-established in the adult mosquito midgut.

  6. Screening of selected ethnomedicinal plants from South Africa for larvicidal activity against the mosquito Anopheles arabiensis

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    Maharaj Rajendra

    2012-09-01

    Full Text Available Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic, that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties. Methods Extracts of a selection of plant taxa sourced in South Africa were tested for larvicidal properties in an applicable assay. Thirty 3rd instar Anopheles arabiensis larvae were exposed to various extract types (dichloromethane, dichloromethane/methanol (1:1, methanol and purified water of each species investigated. Mortality was evaluated relative to the positive control Temephos (Mostop; Agrivo, an effective emulsifiable concentrate larvicide. Results Preliminary screening of crude extracts revealed substantial variation in toxicity with 24 of the 381 samples displaying 100% larval mortality within the seven day exposure period. Four of the high activity plants were selected and subjected to bioassay guided fractionation. The results of the testing of the fractions generated identified one fraction of the plant, Toddalia asiatica as being very potent against the An. arabiensis larvae. Conclusion The present study has successfully identified a plant with superior larvicidal activity at both the crude and semi pure fractions generated through bio-assay guided fractionation. These results have initiated further research into isolating the active compound and developing a malaria vector control tool.

  7. Larvicidal activity of metabolites from the endophytic Podospora sp. against the malaria vector Anopheles gambiae.

    Science.gov (United States)

    Matasyoh, Josphat C; Dittrich, Birger; Schueffler, Anja; Laatsch, Hartmut

    2011-03-01

    In a screening for natural products with mosquito larvicidal activities, the endophytic fungus Podospora sp. isolated from the plant Laggera alata (Asteraceae) was conspicuous. Two xanthones, sterigmatocystin (1) and secosterigmatocystin (2), and an anthraquinone derivative (3) 13-hydroxyversicolorin B were isolated after fermentation on M(2) medium. These compounds were characterised using spectroscopic and X-ray analysis and examined against third instar larvae of Anopheles gambiae. The results demonstrated that compound 1 was the most potent one with LC(50) and LC(90) values of 13.3 and 73.5 ppm, respectively. Over 95% mortality was observed at a concentration 100 ppm after 24 h. These results compared farvorably with the commercial larvicide pylarvex® that showed 100% mortality at the same concentration. Compound 3 was less potent and had an LC(50) of 294.5 ppm and over 95% mortality was achieved at a concentration of 1,000 ppm. Secosterigmatocystin (2) revealed relatively weak activity and therefore LC values were not determined.

  8. Suboptimal Larval Habitats Modulate Oviposition of the Malaria Vector Mosquito Anopheles coluzzii.

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    Eunho Suh

    Full Text Available Selection of oviposition sites by gravid females is a critical behavioral step in the reproductive cycle of Anopheles coluzzii, which is one of the principal Afrotropical malaria vector mosquitoes. Several studies suggest this decision is mediated by semiochemicals associated with potential oviposition sites. To better understand the chemosensory basis of this behavior and identify compounds that can modulate oviposition, we examined the generally held hypothesis that suboptimal larval habitats give rise to semiochemicals that negatively influence the oviposition preference of gravid females. Dual-choice bioassays indicated that oviposition sites conditioned in this manner do indeed foster significant and concentration dependent aversive effects on the oviposition site selection of gravid females. Headspace analyses derived from aversive habitats consistently noted the presence of dimethyl disulfide (DMDS, dimethyl trisulfide (DMTS and 6-methyl-5-hepten-2-one (sulcatone each of which unitarily affected An. coluzzii oviposition preference. Electrophysiological assays across the antennae, maxillary palp, and labellum of gravid An. coluzzii revealed differential responses to these semiochemicals. Taken together, these findings validate the hypothesis in question and suggest that suboptimal environments for An. coluzzii larval development results in the release of DMDS, DMTS and sulcatone that impact the response valence of gravid females.

  9. Preferencias alimenticias del Anopheles pseudopunctipennis y A. triannulatus en el Perú

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    Manuel Acosta

    1960-01-01

    Full Text Available Mediante la prueba serológica de las pricipitinas, entre agosto y noviembre, 1958, se ha tratado de determinar las preferencias alimenticias del Anopheles pseudopunctipennis y del A. triannulatus en varias localidades peruanas, con los siguientes resultados: 1. En una serie, con insectos procedentes de dos regiones geográficas diferentes y usando sueros inmunes correspondientes a la especie humana y a varios animales inferiores, se obtuvo: a que el A. pseudopunctipennis no presenta comportamiento uniforme en cuanto a su alimentación en el hombre; y b que los animales inferiores sobre los que se alimenta con mayor frecuencia son la vaca y el perro. 2. En otra serie, en la que se usó tan sólo el suero anti-hombre, se verificó que el A. pseudopunctipennis había ingerido sangre humana entre el 87.3 y 100.0 por ciento. 3. En 0.5 por ciento de 977 especímenes del A. triannulatus se puso de manifiesto la presencia de sangre humana. 4. Se discute las circunstancias que condicionarían la preferencia que los insectos estudiados suelen mostrar en cuanto a sus huéspedes.

  10. Molecular taxonomy of Anopheles (Nyssorhynchus) benarrochi (Diptera: Culicidae) and malaria epidemiology in southern Amazonian Peru.

    Science.gov (United States)

    Conn, Jan E; Moreno, Marta; Saavedra, Marlon; Bickersmith, Sara A; Knoll, Elisabeth; Fernandez, Roberto; Vera, Hubert; Burrus, Roxanne G; Lescano, Andres G; Sanchez, Juan Francisco; Rivera, Esteban; Vinetz, Joseph M

    2013-02-01

    Anopheline specimens were collected in 2011 by human landing catch, Shannon and CDC traps from the malaria endemic localities of Santa Rosa and San Pedro in Madre de Dios Department, Peru. Most specimens were either Anopheles (Nyssorhynchus) benarrochi B or An. (Nys.) rangeli, confirmed by polymerase chain reaction-restriction fragment length polymorphism-internal transcribed spacer 2 (PCR-RFLP-ITS2) and, for selected individuals, ITS2 sequences. A few specimens from Lupuna, Loreto Department, northern Amazonian Peru, were also identified as An. benarrochi B. A statistical parsimony network using ITS2 sequences confirmed that all Peruvian An. benarrochi B analyzed were identical to those in GenBank from Putumayo, southern Colombia. Sequences of the mtDNA COI BOLD region of specimens from all three Peruvian localities were connected using a statistical parsimony network, although there were multiple mutation steps between northern and southern Peruvian sequences. A Bayesian inference of concatenated Peruvian sequences of ITS2 + COI detected a single clade with very high support for all An. benarrochi B except one individual from Lupuna that was excluded. No samples were positive for Plasmodium by CytB-PCR.

  11. Exploring proteins in Anopheles gambiae male and female antennae through MALDI mass spectrometry profiling.

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    Francesca R Dani

    Full Text Available MALDI profiling and imaging mass spectrometry (IMS are novel techniques for direct analysis of peptides and small proteins in biological tissues. In this work we applied them to the study of Anopheles gambiae antennae, with the a