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Sample records for gambiae sensu stricto

  1. Evidence of multiple pyrethroid resistance mechanisms in the malaria vector Anopheles gambiae sensu stricto from Nigeria.

    PubMed

    Awolola, T S; Oduola, O A; Strode, C; Koekemoer, L L; Brooke, B; Ranson, H

    2009-11-01

    Pyrethroid insecticide resistance in Anopheles gambiae sensu stricto is a major concern to malaria vector control programmes. Resistance is mainly due to target-site insensitivity arising from a single point mutation, often referred to as knockdown resistance (kdr). Metabolic-based resistance mechanisms have also been implicated in pyrethroid resistance in East Africa and are currently being investigated in West Africa. Here we report the co-occurrence of both resistance mechanisms in a population of An. gambiae s.s. from Nigeria. Bioassay, synergist and biochemical analysis carried out on resistant and susceptible strains of An. gambiae s.s. from the same geographical area revealed >50% of the West African kdr mutation in the resistant mosquitoes but <3% in the susceptible mosquitoes. Resistant mosquitoes synergized using pyperonyl butoxide before permethrin exposure showed a significant increase in mortality compared with the non-synergized. Biochemical assays showed an increased level of monooxygenase but not glutathione-S-transferase or esterase activities in the resistant mosquitoes. Microarray analysis using the An. gambiae detox-chip for expression of detoxifying genes showed five over-expressed genes in the resistant strain when compared with the susceptible one. Two of these, CPLC8 and CPLC#, are cuticular genes not implicated in pyrethroid metabolism in An. gambiae s.s, and could constitute a novel set of candidate genes that warrant further investigation. PMID:18829056

  2. Water vapour is a pre-oviposition attractant for the malaria vector Anopheles gambiae sensu stricto

    PubMed Central

    2013-01-01

    Background To date no semiochemicals affecting the pre-oviposition behaviour of the malaria vector Anopheles gambiae sensu lato have been described. Water vapour must be the major chemical signal emanating from a potential larval habitat, and although one might expect that gravid An. gambiae s.l. detect and respond to water vapour in their search for an aquatic habitat, this has never been experimentally confirmed for this species. This study aimed to investigate the role of relative humidity or water vapour as a general cue for inducing gravid An. gambiae sensu stricto to make orientated movements towards the source. Methods Three experiments were carried out with insectary-reared An. gambiae s.s. One with unfed females and two with gravid females during their peak oviposition time in the early evening. First, unfed females and gravid females were tested separately in still air where a humidity difference was established between opposite ends of a WHO bioassay tube and mosquitoes released individually in the centre of the tube. Movement of mosquitoes to either low or high humidity was recorded. Additionally, gravid mosquitoes were released into a larger air-flow olfactometer and responses measured towards collection chambers that contained cups filled with water or empty cups. Results Unfed females equally dispersed in the small bioassay tubes to areas of high and low humidity (mean 50% (95% confidence interval (CI) 38-62%). In contrast, gravid females were 2.4 times (95% CI 1.3-4.7) more likely to move towards high humidity than unfed females. The results were even more pronounced in the airflow olfactometer. Gravid females were 10.6 times (95% CI 5.4-20.8) more likely to enter the chamber with water than a dry chamber. Conclusions Water vapour is a strong pre-oviposition attractant to gravid An. gambiae s.s. in still and moving air and is likely to be a general cue used by mosquitoes for locating aquatic habitats. PMID:24120083

  3. Pyriproxyfen for mosquito control: female sterilization or horizontal transfer to oviposition substrates by Anopheles gambiae sensu stricto and Culex quinquefasciatus

    PubMed Central

    2014-01-01

    Background The use of gravid mosquitoes as vehicles to auto-disseminate larvicides was recently demonstrated for the transfer of pyriproxyfen (PPF) by container-breeding Aedes mosquitoes and presents an appealing idea to explore for other disease vectors. The success of this approach depends on the female’s behaviour, the time of exposure and the amount of PPF that can be carried by an individual. We explore the effect of PPF exposure at seven time points around blood feeding on individual Anopheles gambiae sensu stricto and Culex quinquefasciatus fecundity and ability to transfer in laboratory assays. Method Mosquitoes were exposed to 2.6 mg PPF per m2 at 48, 24 and 0.5 hours before and after a blood meal and on the day of egg-laying. The proportion of exposed females (N = 80-100) laying eggs, the number of eggs laid and hatched was studied. Transfer of PPF to oviposition cups was assessed by introducing 10 late instar insectary-reared An. gambiae s.s. larvae into all the cups and monitored for adult emergence inhibition. Results Exposure to PPF between 24 hours before and after a blood meal had significant sterilizing effects: females of both species were 6 times less likely (Odds ratio (OR) 0.16, 95% confidence interval (CI) 0.10-0.26) to lay eggs than unexposed females. Of the few eggs laid, the odds of an egg hatching was reduced 17 times (OR 0.06, 95% CI 0.04-0.08) in Anopheles but only 1.2 times (OR 0.82, 95% CI 0.73-0.93) in Culex. Adult emergence inhibition from larvae introduced in the oviposition cups was observed only from cups in which eggs were laid. When females were exposed to PPF close to egg laying they transferred enough PPF to reduce emergence by 65-71% (95% CI 62-74%). Conclusion PPF exposure within a day before and after blood feeding affects egg-development in An. gambiae s.s. and Cx. quinquefasciatus and presents a promising opportunity for integrated control of vectors and nuisance mosquitoes. However, sterilized females are

  4. The spatial distribution of Anopheles gambiae sensu stricto and An. arabiensis (Diptera: Culicidae) in Mali.

    PubMed

    Sogoba, N; Vounatsou, P; Bagayoko, M M; Doumbia, S; Dolo, G; Gosoniu, L; Traore, S F; Toure, Y T; Smith, T

    2007-05-01

    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. PMID:18686246

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

    PubMed

    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

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

    PubMed Central

    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

  7. Visual and olfactory associative learning in the malaria vector Anopheles gambiae sensu stricto

    PubMed Central

    2012-01-01

    Background Memory and learning are critical aspects of the ecology of insect vectors of human pathogens because of their potential effects on contacts between vectors and their hosts. Despite this epidemiological importance, there have been only a limited number of studies investigating associative learning in insect vector species and none on Anopheline mosquitoes. Methods A simple behavioural assays was developed to study visual and olfactory associative learning in Anopheles gambiae, the main vector of malaria in Africa. Two contrasted membrane qualities or levels of blood palatability were used as reinforcing stimuli for bi-directional conditioning during blood feeding. Results Under such experimental conditions An. gambiae females learned very rapidly to associate visual (chequered and white patterns) and olfactory cues (presence and absence of cheese or Citronella smell) with the reinforcing stimuli (bloodmeal quality) and remembered the association for up to three days. Associative learning significantly increased with the strength of the conditioning stimuli used. Importantly, learning sometimes occurred faster when a positive reinforcing stimulus (palatable blood) was associated with an innately preferred cue (such as a darker visual pattern). However, the use of too attractive a cue (e.g. Shropshire cheese smell) was counter-productive and decreased learning success. Conclusions The results address an important knowledge gap in mosquito ecology and emphasize the role of associative memory for An. gambiae's host finding and blood-feeding behaviour with important potential implications for vector control. PMID:22284012

  8. Ecological and genetic relationships of the Forest-M form among chromosomal and molecular forms of the malaria vector Anopheles gambiae sensu stricto

    PubMed Central

    Lee, Yoosook; Cornel, Anthony J; Meneses, Claudio R; Fofana, Abdrahamane; Andrianarivo, Aurélie G; McAbee, Rory D; Fondjo, Etienne; Traoré, Sekou F; Lanzaro, Gregory C

    2009-01-01

    Background Anopheles gambiae sensu stricto, one of the principal vectors of malaria, has been divided into two subspecific groups, known as the M and S molecular forms. Recent studies suggest that the M form found in Cameroon is genetically distinct from the M form found in Mali and elsewhere in West Africa, suggesting further subdivision within that form. Methods Chromosomal, microsatellite and geographic/ecological evidence are synthesized to identify sources of genetic polymorphism among chromosomal and molecular forms of the malaria vector Anopheles gambiae s.s. Results Cytogenetically the Forest M form is characterized as carrying the standard chromosome arrangement for six major chromosomal inversions, namely 2La, 2Rj, 2Rb, 2Rc, 2Rd, and 2Ru. Bayesian clustering analysis based on molecular form and chromosome inversion polymorphisms as well as microsatellites describe the Forest M form as a distinct population relative to the West African M form (Mopti-M form) and the S form. The Forest-M form was the most highly diverged of the An. gambiae s.s. groups based on microsatellite markers. The prevalence of the Forest M form was highly correlated with precipitation, suggesting that this form prefers much wetter environments than the Mopti-M form. Conclusion Chromosome inversions, microsatellite allele frequencies and habitat preference all indicate that the Forest M form of An. gambiae is genetically distinct from the other recognized forms within the taxon Anopheles gambiae sensu stricto. Since this study covers limited regions of Cameroon, the possibility of gene flow between the Forest-M form and Mopti-M form cannot be rejected. However, association studies of important phenotypes, such as insecticide resistance and refractoriness against malaria parasites, should take into consideration this complex population structure. PMID:19383163

  9. Fumigant toxicity of the essential oils of some African plants against Anopheles gambiae sensu stricto.

    PubMed

    Omolo, M O; Okinyo, D; Ndiege, I O; Lwande, W; Hassanali, A

    2005-03-01

    The essential oils from 15 species of African plants selected by ethnobotanical considerations and field inspection (odour and presence of insects) were screened for fumigant toxicity to Anopheles gambiae s.s. in the laboratory. Essential oils from 6 species showed varying levels of toxicity, with Conyza newii (Compositae) and Plectranthus marruboides (Labiateae) being the most potent. Fifty compounds representing approximately 74% of the essential oil of C. newii were identified by GC-MS and GC-coinjection (for available standards). The major and some of the minor constituents of the two oils were assayed at different doses. Two compounds, from C. newii, perillaldehyde and perillyl alcohol, exhibited higher fumigant toxicity (LD50 = 1.05 x 10(-4) and 2.52 x 10(-4) mg cm(-3), respectively) than the parent oil (2.0 x 10(-3) mg cm(-3)). GC-MS analysis of the essential oil of P. marruboides gave results similar to that previously reported. Interestingly, none of its components were active, suggesting that the insecticidal activity of the oil results from either some of the minor components or as a blend effect of some of the major constituents. PMID:15830848

  10. What is Antrodia sensu stricto?

    PubMed

    Spirin, Viacheslav; Vlasák, Josef; Niemelä, Tuomo; Miettinen, Otto

    2013-01-01

    The polypore genus Antrodia (Polyporales, Basidiomycota) in the strict sense consists of a small number of species grouped around the type species A. serpens in phylogenetic analyses. This distinct clade (Antrodia sensu stricto in our view) contains species of the Antrodia heteromorpha complex, A. macra coll. and Antrodia mappa (formerly Postia mappa). Nuclear rDNA ITS and tef1 data show that the Antrodia heteromorpha species complex includes four species: A. heteromorpha sensu stricto (mostly on gymnosperms, large pores and spores), A. serpens (on angiosperms in Europe, resupinate, smaller pores but large spores), A. favescens (smaller pores and spores, pileate species in North America, formerly known as Trametes sepium), and A. tanakai (a close kin of A. favescens in Eurasia). Antrodia albida is a synonym of A. heteromorpha sensu stricto. We combine A. mappa, A. favescens and A. tanakai in Antrodia and designate neotypes for A. albida and A. heteromorpha, and an epitype for A. serpens. We also compare the morphologically similar but distantly related A. albidoides and A. mellita, and conclude that A. macrospora and A. subalbidoides are synonyms of A. albidoides. PMID:24311543

  11. Genetic and Environmental Factors Associated with Laboratory Rearing Affect Survival and Assortative Mating but Not Overall Mating Success in Anopheles gambiae Sensu Stricto

    PubMed Central

    Paton, Doug; Touré, Mahamoudou; Sacko, Adama; Coulibaly, Mamadou B.; Traoré, Sékou F.; Tripet, Frédéric

    2013-01-01

    Anopheles gambiae sensu stricto, the main vector of malaria in Africa, is characterized by its vast geographical range and complex population structure. Assortative mating amongst the reproductively isolated cryptic forms that co-occur in many areas poses unique challenges for programs aiming to decrease malaria incidence via the release of sterile or genetically-modified mosquitoes. Importantly, whether laboratory-rearing affects the ability of An. gambiae individuals of a given cryptic taxa to successfully mate with individuals of their own form in field conditions is still unknown and yet crucial for mosquito-releases. Here, the independent effects of genetic and environmental factors associated with laboratory rearing on male and female survival, mating success and assortative mating were evaluated in the Mopti form of An. gambiae over 2010 and 2011. In semi-field enclosures experiments and despite strong variation between years, the overall survival and mating success of male and female progeny from a laboratory strain was not found to be significantly lower than those of the progeny of field females from the same population. Adult progeny from field-caught females reared at the larval stage in the laboratory and from laboratory females reared outdoors exhibited a significant decrease in survival but not in mating success. Importantly, laboratory individuals reared as larvae indoors were unable to mate assortatively as adults, whilst field progeny reared either outdoors or in the laboratory, as well as laboratory progeny reared outdoors all mated significantly assortatively. These results highlight the importance of genetic and environment interactions for the development of An. gambiae's full mating behavioral repertoire and the challenges this creates for mosquito rearing and release-based control strategies. PMID:24391719

  12. A 3D Analysis of Flight Behavior of Anopheles gambiae sensu stricto Malaria Mosquitoes in Response to Human Odor and Heat

    PubMed Central

    Spitzen, Jeroen; Spoor, Cornelis W.; Grieco, Fabrizio; ter Braak, Cajo; Beeuwkes, Jacob; van Brugge, Sjaak P.; Kranenbarg, Sander; Noldus, Lucas P. J. J.; van Leeuwen, Johan L.; Takken, Willem

    2013-01-01

    Female mosquitoes use odor and heat as cues to navigate to a suitable landing site on their blood host. The way these cues affect flight behavior and modulate anemotactic responses, however, is poorly understood. We studied in-flight behavioral responses of females of the nocturnal malaria mosquito Anopheles gambiae sensu stricto to human odor and heat. Flight-path characteristics in a wind tunnel (flow 20 cm/s) were quantified in three dimensions. With wind as the only stimulus (control), short and close to straight upwind flights were recorded. With heat alone, flights were similarly short and direct. The presence of human odor, in contrast, caused prolonged and highly convoluted flight patterns. The combination of odor+heat resulted in longer flights with more landings on the source than to either cue alone. Flight speed was greatest (mean groundspeed 27.2 cm/s) for odor+heat. Odor alone resulted in decreased flight speed when mosquitoes arrived within 30 cm of the source whereas mosquitoes exposed to odor+heat maintained a high flight speed while flying in the odor plume, until they arrived within 15 cm of the source. Human odor evoked an increase in crosswind flights with an additive effect of heat at close range (<15 cm) to the source. This was found for both horizontal and vertical flight components. However, mosquitoes nevertheless made upwind progress when flying in the odor+heat generated plume, suggesting that mosquitoes scan their environment intensively while they progress upwind towards their host. These observations may help to improve the efficacy of trapping systems for malaria mosquitoes by (1) optimizing the site of odor release relative to trap entry and (2) adding a heat source which enhances a landing response. PMID:23658792

  13. Differential Induction of Proteins in Anopheles gambiae sensu stricto (Diptera: Cullicidae) Larvae in Response to Heavy Metal Selection

    PubMed Central

    Mireji, Paul O.; Keating, Joseph; Kenya, Eucharia; Mbogo, Charles; Nyambaka, Hudson; Osir, Ellie; Githure, John; Beier, John

    2009-01-01

    Investigations were conducted to establish the magnitude and pattern of differential expression of proteins due to generational selection of third instar An. gambiae s.s. larvae by cadmium, copper and lead heavy metals, three possible common urban pollutants. A susceptible strain of An. gambiae s.s. third instar larvae was separately placed under selection pressure with cadmium, copper and lead at LC30 and controls through five generations. First, third and fifth generation selection survivors were screened for differentially expressed proteins relative to non-exposed control by two-dimensional gel electrophoresis. Distribution patterns of the spots were analysed by Chi Square or Fishers exact test and variations in expressions between and within generation by ANOVA. Most differentially expressed spots were acidic and of low molecular weight among all metals and generations. Type of heavy metals and generation were main indicators of variations in differential expressions. Variation between generations was most significant among cadmium-selected populations of which most number of spots were induced in the fifth generation. Most spots were induced in the copper-selected population in the third generation. The induced protein spots may be products from respective genes that respond to heavy metals and counter their toxicity, thus building An. gambiae s.s. tolerance to these pollutants. The differential pattern and magnitude of expressed spots has potential application as molecular markers for assessment of anopheline adaptation status to heavy metals, and provide insight into the extent of environmental pollution. PMID:20651951

  14. Effect of temperature on the development of the aquatic stages of Anopheles gambiae sensu stricto (Diptera: Culicidae).

    PubMed

    Bayoh, M N; Lindsay, S W

    2003-10-01

    Global warming may affect the future pattern of many arthropod-borne diseases, yet the relationship between temperature and development has been poorly described for many key vectors. Here the development of the aquatic stages of Africa's principal malaria vector, Anopheles gambiae s.s. Giles, is described at different temperatures. Development time from egg to adult was measured under laboratory conditions at constant temperatures between 10 and 40 degrees C. Rate of development from one immature stage to the next increased at higher temperatures to a peak around 28 degrees C and then declined. Adult development rate was greatest between 28 and 32 degrees C, although adult emergence was highest between 22 and 26 degrees C. No adults emerged below 18 degrees C or above 34 degrees C. Non-linear models were used to describe the relationship between developmental rate and temperature, which could be used for developing process-based models of malaria transmission. The utility of these findings is demonstrated by showing that a map where the climate is suitable for the development of aquatic stages of A. gambiae s.s. corresponded closely with the best map of malaria risk currently available for Africa. PMID:14641976

  15. Modeling the role of environmental variables on the population dynamics of the malaria vector Anopheles gambiae sensu stricto

    PubMed Central

    2012-01-01

    Background The impact of weather and climate on malaria transmission has attracted considerable attention in recent years, yet uncertainties around future disease trends under climate change remain. Mathematical models provide powerful tools for addressing such questions and understanding the implications for interventions and eradication strategies, but these require realistic modeling of the vector population dynamics and its response to environmental variables. Methods Published and unpublished field and experimental data are used to develop new formulations for modeling the relationships between key aspects of vector ecology and environmental variables. These relationships are integrated within a validated deterministic model of Anopheles gambiae s.s. population dynamics to provide a valuable tool for understanding vector response to biotic and abiotic variables. Results A novel, parsimonious framework for assessing the effects of rainfall, cloudiness, wind speed, desiccation, temperature, relative humidity and density-dependence on vector abundance is developed, allowing ease of construction, analysis, and integration into malaria transmission models. Model validation shows good agreement with longitudinal vector abundance data from Tanzania, suggesting that recent malaria reductions in certain areas of Africa could be due to changing environmental conditions affecting vector populations. Conclusions Mathematical models provide a powerful, explanatory means of understanding the role of environmental variables on mosquito populations and hence for predicting future malaria transmission under global change. The framework developed provides a valuable advance in this respect, but also highlights key research gaps that need to be resolved if we are to better understand future malaria risk in vulnerable communities. PMID:22877154

  16. An age–size reaction norm yields insight into environmental interactions affecting life-history traits: a factorial study of larval development in the malaria mosquito Anopheles gambiae sensu stricto

    PubMed Central

    Phelan, Conan; Rotiberg, Bernard D

    2013-01-01

    Environmental factors frequently act nonindependently to determine growth and development of insects. Because age and size at maturity strongly influence population dynamics, interaction effects among environmental variables complicate the task of predicting dynamics of insect populations under novel conditions. We reared larvae of the African malaria mosquito Anopheles gambiae sensu stricto (s.s.) under three factors relevant to changes in climate and land use: food level, water depth, and temperature. Each factor was held at two levels in a fully crossed design, for eight experimental treatments. Larval survival, larval development time, and adult size (wing length) were measured to indicate the importance of interaction effects upon population-level processes. For age and size at emergence, but not survival, significant interaction effects were detected for all three factors, in addition to sex. Some of these interaction effects can be understood as consequences of how the different factors influence energy usage in the context of a nonindependent relationship between age and size. Experimentally assessing interaction effects for all potential future sets of conditions is intractable. However, considering how different factors affect energy usage within the context of an insect's evolved developmental program can provide insight into the causes of complex environmental effects on populations. PMID:23919132

  17. Genomic Insights into the Saccharomyces sensu stricto Complex

    PubMed Central

    Borneman, Anthony R.; Pretorius, Isak S.

    2015-01-01

    The Saccharomyces sensu stricto group encompasses species ranging from the industrially ubiquitous yeast Saccharomyces cerevisiae to those that are confined to geographically limited environmental niches. The wealth of genomic data that are now available for the Saccharomyces genus is providing unprecedented insights into the genomic processes that can drive speciation and evolution, both in the natural environment and in response to human-driven selective forces during the historical “domestication” of these yeasts for baking, brewing, and winemaking. PMID:25657346

  18. Salinity tolerance of Anopheles farauti Laveran sensu stricto.

    PubMed

    Bell, D; Bryan, J; Cameron, A; Foley, D; Pholsyna, K

    1999-01-01

    To assess the salt tolerance of the malaria vector Anopheles farauti sensu stricto, larvae were collected from a freshwater environment on the outskirts of Honiara, Solomon Islands and placed in trays containing water with salinity varying from freshwater to seawater. Dead larvae and pupae and emerged adults were recorded and preserved. Most adults and nearly half of the larvae and pupae were then subjected to DNA analysis for species identification. No adult An. farauti emerged after prolonged immersion of larvae in undiluted seawater (3.5% salinity), although temporary immersion before pupation was compatible with survival. Salinities of up to 2.2% to 2.5% were compatible with good survival and adult emergence, at least from fourth instars. The results suggest that higher salinities may slow larval development and show that mortality at a given salinity is not uniform. PMID:11061001

  19. Microdiversity of Echinococcus granulosus sensu stricto in Australia.

    PubMed

    Alvarez Rojas, C A; Ebi, D; Gauci, C G; Scheerlinck, J P; Wassermann, M; Jenkins, D J; Lightowlers, M W; Romig, T

    2016-07-01

    Echinococcus granulosus (sensu lato) is now recognized as an assemblage of cryptic species, which differ considerably in morphology, development, host specificity (including infectivity/pathogenicity for humans) and other aspects. One of these species, E. granulosus sensu stricto (s.s.), is now clearly identified as the principal agent causing cystic echinococcosis in humans. Previous studies of a small section of the cox1 and nadh1 genes identified two variants of E. granulosus s.s. to be present in Australia; however, no further work has been carried out to characterize the microdiversity of the parasite in its territory. We have analysed the sequence of the full length of the cox1 gene (1609 bp) from 37 isolates of E. granulosus from different hosts and geographic regions of Australia. The analysis shows that seven haplotypes of E. granulosus s.s. not previously described were found, together with five haplotypes known to be present in other parts of the world, including the haplotype EG01 which is widespread and present in all endemic regions. These data extend knowledge related to the geographical spread and host range of E. granulosus s.s. in a country such as Australia in which the parasite established around 200 years ago. PMID:27041115

  20. A novel zoonotic genotype related to Echinococcus granulosus sensu stricto from southern Ethiopia.

    PubMed

    Wassermann, Marion; Woldeyes, Daniel; Gerbi, Banchwosen Mechal; Ebi, Dennis; Zeyhle, Eberhard; Mackenstedt, Ute; Petros, Beyene; Tilahun, Getachew; Kern, Peter; Romig, Thomas

    2016-09-01

    Complete mitochondrial and two nuclear gene sequences of a novel genotype (GOmo) related to Echinococcus granulosus sensu stricto are described from a metacestode isolate retrieved from a human patient in southwestern Ethiopia. Phylogenetically, the genotype is positioned within the E. granulosus sensu stricto/Echinococcus felidis cluster, but cannot easily be allocated to either species. Based on different mitochondrial DNA markers, it is closest to the haplotype cluster that currently defines the species E. granulosus sensu stricto (which includes variants showing the widely cited G1, G2 and G3 sequences), but is clearly not part of this cluster. Pairwise distances between GOmo and E. granulosus sensu stricto are in the range of those between the most distant members of the Echinococcus canadensis complex (G6-10) that were recently proposed as separate species. At this stage, we prefer to list GOmo informally as a genotype rather than giving it any taxonomic rank because our knowledge rests on a single isolate from a dead-end host (human), and its lifecycle is unknown. According to data on molecularly characterised Echinococcus isolates from this region, GOmo has never been found in the usual livestock species that carry cystic echinococcosis and the possibility of a wildlife source of this newly recognised zoonotic agent cannot be excluded. The discovery of GOmo adds complexity to the already diverse array of cystic echinococcosis agents in sub-Saharan Africa and challenges hypotheses on the biogeographical origin of the E. granulosus sensu stricto clade. PMID:27181929

  1. Sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto)

    PubMed Central

    2014-01-01

    We describe a case of sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto). This case confirms that MultiLocus sequence typing and variable-number tandem-repeat methods are very robust techniques to identify the pathogen species and to validate molecular epidemiological links among complex M. abscessus isolates. PMID:24479655

  2. Population subdivision of Fusarium graminearum sensu stricto in the Upper Midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A collection of 712 Fusarium graminearum sensu stricto strains, originating from 52 counties and 83 wheat and barley fields from nine states within the United States and predominantly gathered between 1999-2000 was characterized by RFLPs and PCR-based trichothecene type analyses and compared with 19...

  3. Bread, beer and wine: yeast domestication in the Saccharomyces sensu stricto complex.

    PubMed

    Sicard, Delphine; Legras, Jean-Luc

    2011-03-01

    Yeasts of the Saccharomyces sensu stricto species complex are able to convert sugar into ethanol and CO(2) via fermentation. They have been used for thousands years by mankind for fermenting food and beverages. In the Neolithic times, fermentations were probably initiated by naturally occurring yeasts, and it is unknown when humans started to consciously add selected yeast to make beer, wine or bread. Interestingly, such human activities gave rise to the creation of new species in the Saccharomyces sensu stricto complex by interspecies hybridization or polyploidization. Within the S. cerevisiae species, they have led to the differentiation of genetically distinct groups according to the food process origin. Although the evolutionary history of wine yeast populations has been well described, the histories of other domesticated yeasts need further investigation. PMID:21377618

  4. Effectiveness of disinfectants used in hemodialysis against both Candida orthopsilosis and C. parapsilosis sensu stricto biofilms.

    PubMed

    Pires, Regina Helena; da Silva, Julhiany de Fátima; Gomes Martins, Carlos Henrique; Fusco Almeida, Ana Marisa; Pienna Soares, Christiane; Soares Mendes-Giannini, Maria José

    2013-05-01

    Biofilms have been observed in the fluid pathways of hemodialysis machines. The impacts of four biocides used for the disinfection of hemodialysis systems were tested against Candida parapsilosis sensu stricto and Candida orthopsilosis biofilms generated by isolates obtained from a hydraulic circuit that were collected in a hemodialysis unit. Acetic acid was shown to be the most effective agent against Candida biofilms. Strategies for effective disinfection procedures used for hemodialysis systems should also seek to kill and inhibit biofilms. PMID:23478969

  5. Habitat discrimination by gravid Anopheles gambiae sensu lato – a push-pull system

    PubMed Central

    2014-01-01

    Background The non-random distribution of anopheline larvae in natural habitats suggests that gravid females discriminate between habitats of different quality. Whilst physical and chemical cues used by Culex and Aedes vector mosquitoes for selecting an oviposition site have been extensively studied, those for Anopheles remain poorly explored. Here the habitat selection by Anopheles gambiae sensu lato (s.l.), the principal African malaria vector, was investigated when presented with a choice of two infusions made from rabbit food pellets, or soil. Methods Natural colonization and larval survival was evaluated in artificial ponds filled randomly with either infusion. Dual-choice, egg-count bioassays evaluated the responses of caged gravid females to (1) two- to six-day old infusions versus lake water; (2) autoclaved versus non-autoclaved soil infusions; and assessed (3) the olfactory memory of gravid females conditioned in pellet infusion as larvae. Results Wild Anopheles exclusively colonized ponds with soil infusion and avoided those with pellet infusion. When the individual infusions were tested in comparison with lake water, caged An. gambiae sensu stricto (s.s.) showed a dose response: females increasingly avoided the pellet infusion with increasing infusion age (six-day versus lake water: odds ratio (OR) 0.22; 95% confidence interval (CI) 0.1-0.5) and showed increasing preference to lay eggs as soil infusion age increased (six-day versus lake water: OR 2.1; 95% CI 1.4-3.3). Larvae survived in soil infusions equally well as in lake water but died in pellet infusions. Anopheles gambiae s.s. preferred to lay eggs in the non-autoclaved soil (OR 2.6; 95% CI 1.8-3.7) compared with autoclaved soil. There was no change in the avoidance of pellet infusion by individuals reared in the infusion compared with those reared in lake water. Conclusion Wild and caged An. gambiae s.l. females discriminate between potential aquatic habitats for oviposition. These choices benefit

  6. Candida parapsilosis sensu stricto and the closely related species Candida orthopsilosis and Candida metapsilosis in vulvovaginal candidiasis.

    PubMed

    Zhu, Yuxia; Shan, Yingying; Fan, Shangrong; Li, Jianling; Liu, Xiaoping

    2015-02-01

    This study aimed to determine the clinical characteristics and in vitro susceptibilities of Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis isolates from patients with vulvovaginal candidiasis (VVC). We analysed 63 vaginal C. parapsilosis specimens. After the molecular analyses, the isolates were characterised as C. parapsilosis sensu stricto (77.8%), C. orthopsilosis (7.9%) and C. metapsilosis (14.3%). The signs and symptoms of VVC caused by C. parapsilosis sensu lato, including itching, erythema and abnormal discharge, were milder than those caused by C. albicans. None of the C. parapsilosis sensu lato isolates were resistant to fluconazole, miconazole or itraconazole. The resistance rates of C. albicans to fluconazole, itraconazole, miconazole and clotrimazole were 2.3, 1.5, 3.1 and 0.8%, respectively. Both C. parapsilosis sensu lato and C. albicans were susceptible to nystatin. The mycological eradication rate at follow-up days 7-14 and 30-35 were 77.8% (49/63) and 76.2% (48/63), respectively, when treated with various antifungal agents and regimens. We conclude that C. parapsilosis sensu stricto and the closely related species C. orthopsilosis and C. metapsilosis were present in the vaginal samples of VVC patients. The symptoms and signs of VVC caused by C. parapsilosis are milder than those caused by C. albicans. The antifungal susceptibility and therapeutic efficacy in patients colonised by C. parapsilosis sensu lato were similar to those observed in C. albicans-colonised patients. PMID:25322705

  7. Sporothrix schenckii sensu stricto isolated from soil in an armadillo's burrow.

    PubMed

    Rodrigues, Anderson Messias; Bagagli, Eduardo; de Camargo, Zoilo Pires; Bosco, Sandra de Moraes Gimenes

    2014-04-01

    Sporotrichosis is a polymorphic disease of man and animals caused by traumatic implantation of propagules into the skin and subcutaneous tissue. Pathogenic species includes S. brasiliensis, S. schenckii, S. globosa and S. luriei. The disease is remarkable for its occurrence as sapronoses and/or zoonosis outbreaks in tropical and subtropical areas; although, the ecology of the clinical clade is still puzzling. Here, we describe an anamorphic Sporothrix strain isolated from soil in an armadillo's burrow, which was located in a hyper endemic area of Paracoccidioidomycosis in Brazil. This isolate was identified as S. schenckii sensu stricto (Clade IIa) based on morphological and physiological characteristics and phylogenetic analyses of calmodulin sequences. We then discuss the role of the nine-banded armadillo Dasypus novemcinctus as a natural carrier of Sporothrix propagules to better understand Sporothrix sources in nature and reveal essential aspects about the pathogen's eco-epidemiology. PMID:24577793

  8. Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia.

    PubMed

    Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

    2015-12-01

    Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles. PMID:26314229

  9. A new species of Tenuipalpus sensu stricto (Acari: Tenuipalpidae) from Brazil, with ontogeny and a key to the known species.

    PubMed

    Castro, Elizeu B; Feres, Reinaldo J F; Ochoa, Ronald; Bauchan, Gary R

    2016-01-01

    The Cerrado is the second largest Brazilian biome, and is considered to be a "hotspot" due the great concentration of endemic species and high rate of deforestation. Surveys of the mite fauna present in this biome have revealed a great number of new species. In this paper, we describe Tenuipalpus spinosaurus sp. nov. (Acari: Tenuipalpidae), a new species of Tenuipalpus sensu stricto, from adult females, deutonymphs, protonymphs, larvae and eggs, collected on Terminalia argentea (Combretaceae), from the Cerrado in Brazil. Females of this new species bear a prominent longitudinal crest on the opisthosoma. The ontogenetic changes in the idiosoma and leg chaetotaxy of all stages are presented. A key to the world species of Tenuipalpus sensu stricto is provided. PMID:27394345

  10. Molecular characterization of Echinococcus granulosus sensu stricto and Echinococcus canadensis in humans and livestock from Algeria.

    PubMed

    Zait, Houria; Kouidri, Mokhtaria; Grenouillet, Florence Elisabeth; Umhang, Gérald; Millon, Laurence; Hamrioui, Boussad; Grenouillet, Frédéric

    2016-06-01

    In Algeria, previous studies investigated genotypes of Echinococcus granulosus sensu lato in animals and identified E. granulosus sensu stricto (s.s.) genotypes G1 and G3 whereas Echinococcus canadensis genotype G6 was only reported from dromedary cysts. Molecular data on human cystic echinococcosis (CE) were limited. We implemented a large genotyping study of hydatid cysts from humans and livestock animals to specify CE's molecular epidemiology and the genetic diversity in Algeria. Fifty-four human CE cysts from patients predominantly admitted in surgical units from Mustapha Hospital, Algiers, and 16 cysts from livestock animals gathered in two geographically distinct slaughterhouses, Tiaret and Tamanrasset, were collected. Molecular characterization was performed using sequencing of two mitochondrial genes, cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit I (NDI). In humans, G1 of E. granulosus s.s. was the main genotype (90.7 %); four samples (7.4 %) were characterized as E. granulosus s.s. G3 and one cyst as E. canadensis G6 (1.8 %). This molecular confirmation of E. canadensis G6 human infection in Algeria was observed in a Tuareg female living in a desertic area in Tamanrasset. All cysts from sheep, cattle, and goat were identified as E. granulosus s.s. G1 and the two cysts originating from dromedary as E. canadensis G6. Twenty concatenated haplotypes (COI + NDI) were characterized. Among E. granulosus s.s., one haplotype (HL1) was highly predominant in both humans and animals cysts (71.6 %). This study revealed main occurrence of E. granulosus s.s. in humans and livestock animals, with description of a predominant shared haplotype corresponding to the main worldwide observed haplotype E.granulosus s.s. G1. E. canadensis G6 was limited to South Algeria, in dromedary as well as in human. PMID:27021186

  11. In Vitro Activities of Amphotericin B, Terbinafine, and Azole Drugs against Clinical and Environmental Isolates of Aspergillus terreus Sensu Stricto

    PubMed Central

    Fernández, Mariana S.; Rojas, Florencia D.; Cattana, María E.; Sosa, María de los Ángeles; Iovannitti, Cristina A.; Giusiano, Gustavo E.

    2015-01-01

    The antifungal susceptibilities of 40 clinical and environmental isolates of A. terreus sensu stricto to amphotericin B, terbinafine, itraconazole, and voriconazole were determined in accordance with CLSI document M38-A2. All isolates had itraconazole and voriconazole MICs lower than epidemiologic cutoff values, and 5% of the isolates had amphotericin B MICs higher than epidemiologic cutoff values. Terbinafine showed the lowest MICs. No significant differences were found when MICs of clinical and environmental isolates were compared. PMID:25824228

  12. A world revision of the bee fly tribe Usiini (Diptera, Bombyliidae) Part 2: Usia sensu stricto.

    PubMed

    Gibbs, David

    2014-01-01

    This is the second part of a world revision of the genera Usia Latreille and Parageron Paramonov, of the tribe Usiini Becker, and covers the pale-haired species, the Usia sensu stricto group. Usia sensu stricto as defined here contains 24 species of which 16 species fall into two monophyletic groups, the U. lata group with 10 species and the U. florea group with six species. Eight species cannot be placed in either of these two groups, four of them form two pairs of sibling species while the remaining four species have no clear affinities. Of the 25 formerly available names that belong in Usia sensu stricto, U. putilla Becker stat. rev., previously synonymised under U. angustifrons, is reinstated as a full species. U. sicula Egger syn. nov., is synonymised under U. manca Loew, U. anus Becker syn. nov., is synonymised under U. vestita Macquart and U. claripennis Macquart syn. nov., is synonymised under U. atrata (Fabricius). Usia vicina Macquart, formerly placed as a synonym of U. atrata, is shown to be a junior synonym of U. aenea Rossi. Five new species are described, U. anatoliensis sp. nov., U. annetteae sp. nov., U. greatheadi sp. nov., U. maghrebensis sp. nov. and U. cornigera sp. nov. Both the male and female genitalia are illustrated in detail for 21 species, female only in the cases of U. calva Loew and U. notata Loew and male only for U. incognita Paramonov. PMID:24870868

  13. Evidence for Host-Genotype Associations of Borrelia burgdorferi Sensu Stricto

    PubMed Central

    Mechai, Samir; Margos, Gabriele; Feil, Edward J.; Barairo, Nicole; Lindsay, L. Robbin; Michel, Pascal; Ogden, Nicholas H.

    2016-01-01

    Different genotypes of the agent of Lyme disease in North America, Borrelia burgdorferi sensu stricto, show varying degrees of pathogenicity in humans. This variation in pathogenicity correlates with phylogeny and we have hypothesized that the different phylogenetic lineages in North America reflect adaptation to different host species. In this study, evidence for host species associations of B. burgdorferi genotypes was investigated using 41 B. burgdorferi-positive samples from five mammal species and 50 samples from host-seeking ticks collected during the course of field studies in four regions of Canada: Manitoba, northwestern Ontario, Quebec, and the Maritimes. The B. burgdorferi genotypes in the samples were characterized using three established molecular markers (multi-locus sequence typing [MLST], 16S-23S rrs-rrlA intergenic spacer, and outer surface protein C sequence [ospC] major groups). Correspondence analysis and generalized linear mixed effect models revealed significant associations between B. burgdorferi genotypes and host species (in particular chipmunks, and white-footed mice and deer mice), supporting the hypotheses that host adaptation contributes to the phylogenetic structure and possibly the observed variation in pathogenicity in humans. PMID:26901761

  14. Echinococcus equinus and Echinococcus granulosus sensu stricto from the United Kingdom: genetic diversity and haplotypic variation.

    PubMed

    Boufana, Belgees; Lett, Wai San; Lahmar, Samia; Buishi, Imad; Bodell, Anthony J; Varcasia, Antonio; Casulli, Adriano; Beeching, Nicholas J; Campbell, Fiona; Terlizzo, Monica; McManus, Donald P; Craig, Philip S

    2015-02-01

    Cystic echinococcosis is endemic in Europe including the United Kingdom. However, information on the molecular epidemiology of Echinococcus spp. from the United Kingdom is limited. Echinococcus isolates from intermediate and definitive animal hosts as well as from human cystic echinococcosis cases were analysed to determine species and genotypes within these hosts. Echinococcus equinus was identified from horse hydatid isolates, cysts retrieved from captive UK mammals and copro-DNA of foxhounds and farm dogs. Echinococcus granulosus sensu stricto (s.s.) was identified from hydatid cysts of sheep and cattle as well as in DNA extracted from farm dog and foxhound faecal samples, and from four human cystic echinococcosis isolates, including the first known molecular confirmation of E. granulosus s.s. infection in a Welsh sheep farmer. Low genetic variability for E. equinus from various hosts and from different geographical locations was detected using the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), indicating the presence of a dominant haplotype (EQUK01). In contrast, greater haplotypic variation was observed for E. granulosus s.s. cox1 sequences. The haplotype network showed a star-shaped network with a centrally placed main haplotype (EgUK01) that had been reported from other world regions. PMID:25479251

  15. First insights into the genetic diversity of Echinococcus granulosus sensu stricto (s.s.) in Serbia.

    PubMed

    Debeljak, Zoran; Boufana, Belgees; Interisano, Maria; Vidanovic, Dejan; Kulisic, Zoran; Casulli, Adriano

    2016-06-15

    Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu stricto (s.s.) is a cosmopolitan zoonotic infection which is endemic in Serbia where it is subject to mandatory reporting. However, information on the incidence of the disease in humans and prevalence of hydatid infection in livestock remains limited. We used sequenced data of the cytochrome c oxidase subunit 1 (cox 1) mitochondrial gene to examine the genetic diversity and population structure of E. granulosus (s.s.) from intermediate hosts from Serbia. We also compared our generated nucleotide sequences with those reported for neighbouring European countries. Echinococcus canadensis was molecularly confirmed from pig and human hydatid isolates. E. granulosus (G1) was confirmed from sheep and cattle hydatid isolates as well as the first molecular confirmation in Serbia of E. granulosus G2 in sheep and E. granulosus G3 in sheep and cattle hydatid isolates. The Serbian E. granulosus (s.s.) parsimony network displayed 2 main haplotypes (SB02 and SB05) which together with the neutrality indices were suggestive of bottleneck and/or balancing selection. Haplotype analysis showed the presence of the common E. granulosus haplotype described from other worldwide regions. Investigation of the pairwise fixation (Fst) index suggested that Serbian populations of E. granulosus (s.s.) from sheep and cattle hosts showed moderate genetic differentiation. Six of the Serbian haplotypes (SB02-SB07) were shared with haplotypes from Bulgaria, Hungary and/or Romania. Further studies using a larger number of hydatid isolates from various locations across Serbia will provide more information on the genetic structure of E. granulosus (s.s.) within this region. PMID:27198778

  16. Genetic diversity of ospC in a local population of Borrelia burgdorferi sensu stricto.

    PubMed Central

    Wang, I N; Dykhuizen, D E; Qiu, W; Dunn, J J; Bosler, E M; Luft, B J

    1999-01-01

    The outer surface protein, OspC, is highly variable in Borrelia burgdorferi sensu stricto, the agent of Lyme disease. We have shown that even within a single population OspC is highly variable. The variation of ospA and ospC in the 40 infected deer ticks collected from a single site on Shelter Island, New York, was determined using PCR-SSCP. There is very strong apparent linkage disequilibrium between ospA and ospC alleles, even though they are located on separate plasmids. Thirteen discernible SSCP mobility classes for ospC were identified and the DNA sequence for each was determined. These sequences, combined with 40 GenBank sequences, allow us to define 19 major ospC groups. Sequences within a major ospC group are, on average, <1% different from each other, while sequences between major ospC groups are, on average, approximately 20% different. The tick sample contains 11 major ospC groups, GenBank contains 16 groups, with 8 groups found in both samples. Thus, the ospC variation within a local population is almost as great as the variation of a similar-sized sample of the entire species. The Ewens-Watterson-Slatkin test of allele frequency showed significant deviation from the neutral expectation, indicating balancing selection for these major ospC groups. The variation represented by major ospC groups needs to be considered if the OspC protein is to be used as a serodiagnostic antigen or a vaccine. PMID:9872945

  17. Detection of Borrelia burgdorferi sensu stricto and Borrelia garinii DNAs in patient with Hyperkeratosis lenticularis perstans (Flegel disease).

    PubMed

    Schwarzova, Katarina; Kozub, Peter; Szep, Zoltan; Golovchenko, Marina; Rudenko, Natasha

    2016-09-01

    Determination of the causative agent of erythema-like skin lesions in case of nonspecific superficial perivascular dermatitis was supported by histological examination and led to the latter diagnosis of Hyperkeratosis lenticularis perstans (Flegel disease) in patient. The presence of antibodies against Borrelia burgdorferi in patient serum was confirmed by a routine ELISA method and verified by Western blot technique. Skin biopsy and blood specimens were analyzed by PCR and multilocus sequence analysis (MLSA). Western blot method revealed IgG antibody response against two specific antigens, 17 and 83 kDa proteins. The recombinant test detected IgG antibody response against p100 and p41 antigens. The sequence analysis of amplicons from the selected genomic loci obtained from skin biopsy and serum samples revealed the presence of two species from B. burgdorferi sensu lato complex as a co-infection in this patient-B. burgdorferi sensu stricto (s.s.) and Borrelia garinii. PMID:26769152

  18. Discrimination between E. granulosus sensu stricto, E. multilocularis and E. shiquicus Using a Multiplex PCR Assay

    PubMed Central

    Li, Li; Yan, Hong-Bin; Blair, David; Lei, Meng-Tong; Cai, Jin-Zhong; Fan, Yan-Lei; Li, Jian-Qiu; Fu, Bao-Quan; Yang, Yu-Rong; McManus, Donald P.; Jia, Wan-Zhong

    2015-01-01

    Background Infections of Echinococcus granulosus sensu stricto (s.s), E. multilocularis and E. shiquicus are commonly found co-endemic on the Qinghai-Tibet plateau, China, and an efficient tool is needed to facilitate the detection of infected hosts and for species identification. Methodology/Principal Findings A single-tube multiplex PCR assay was established to differentiate the Echinococcus species responsible for infections in intermediate and definitive hosts. Primers specific for E. granulosus, E. multilocularis and E. shiquicus were designed based on sequences of the mitochondrial NADH dehydrogenase subunit 1 (nad1), NADH dehydrogenase subunit 5 (nad5) and cytochrome c oxidase subunit 1 (cox1) genes, respectively. This multiplex PCR accurately detected Echinococcus DNA without generating nonspecific reaction products. PCR products were of the expected sizes of 219 (nad1), 584 (nad5) and 471 (cox1) bp. Furthermore, the multiplex PCR enabled diagnosis of multiple infections using DNA of protoscoleces and copro-DNA extracted from fecal samples of canine hosts. Specificity of the multiplex PCR was 100% when evaluated using DNA isolated from other cestodes. Sensitivity thresholds were determined for DNA from protoscoleces and from worm eggs, and were calculated as 20 pg of DNA for E. granulosus and E. shiquicus, 10 pg of DNA for E. multilocularis, 2 eggs for E. granulosus, and 1 egg for E. multilocularis. Positive results with copro-DNA could be obtained at day 17 and day 26 after experimental infection of dogs with larval E. multilocularis and E. granulosus, respectively. Conclusions/Significance The multiplex PCR developed in this study is an efficient tool for discriminating E. granulosus, E. multilocularis and E. shiquicus from each other and from other taeniid cestodes. It can be used for the detection of canids infected with E. granulosus s.s. and E. multilocularis using feces collected from these definitive hosts. It can also be used for the identification

  19. Differences in Genotype, Clinical Features, and Inflammatory Potential of Borrelia burgdorferi sensu stricto Strains from Europe and the United States.

    PubMed

    Cerar, Tjasa; Strle, Franc; Stupica, Dasa; Ruzic-Sabljic, Eva; McHugh, Gail; Steere, Allen C; Strle, Klemen

    2016-05-01

    Borrelia burgdorferi sensu stricto isolates from patients with erythema migrans in Europe and the United States were compared by genotype, clinical features of infection, and inflammatory potential. Analysis of outer surface protein C and multilocus sequence typing showed that strains from these 2 regions represent distinct genotypes. Clinical features of infection with B. burgdorferi in Slovenia were similar to infection with B. afzelii or B. garinii, the other 2 Borrelia spp. that cause disease in Europe, whereas B. burgdorferi strains from the United States were associated with more severe disease. Moreover, B. burgdorferi strains from the United States induced peripheral blood mononuclear cells to secrete higher levels of cytokines and chemokines associated with innate and Th1-adaptive immune responses, whereas strains from Europe induced greater Th17-associated responses. Thus, strains of the same B. burgdorferi species from Europe and the United States represent distinct clonal lineages that vary in virulence and inflammatory potential. PMID:27088349

  20. Differences in Genotype, Clinical Features, and Inflammatory Potential of Borrelia burgdorferi sensu stricto Strains from Europe and the United States

    PubMed Central

    Cerar, Tjasa; Strle, Franc; Stupica, Dasa; Ruzic-Sabljic, Eva; McHugh, Gail; Steere, Allen C.

    2016-01-01

    Borrelia burgdorferi sensu stricto isolates from patients with erythema migrans in Europe and the United States were compared by genotype, clinical features of infection, and inflammatory potential. Analysis of outer surface protein C and multilocus sequence typing showed that strains from these 2 regions represent distinct genotypes. Clinical features of infection with B. burgdorferi in Slovenia were similar to infection with B. afzelii or B. garinii, the other 2 Borrelia spp. that cause disease in Europe, whereas B. burgdorferi strains from the United States were associated with more severe disease. Moreover, B. burgdorferi strains from the United States induced peripheral blood mononuclear cells to secrete higher levels of cytokines and chemokines associated with innate and Th1-adaptive immune responses, whereas strains from Europe induced greater Th17-associated responses. Thus, strains of the same B. burgdorferi species from Europe and the United States represent distinct clonal lineages that vary in virulence and inflammatory potential. PMID:27088349

  1. Experimental challenge of Anisakis simplex sensu stricto and Anisakis pegreffii (Nematoda: Anisakidae) in rainbow trout and olive flounder.

    PubMed

    Quiazon, Karl Marx A; Yoshinaga, Tomoyoshi; Ogawa, Kazuo

    2011-06-01

    The third-stage larvae of Anisakis simplex sensu lato (s.l.) are found in many marine fishes. To ensure food safety, it is important to determine whether these larvae are present in the body muscle of commercial fish species. However, there is little information regarding the tissue specificity of Anisakis and two of its sibling species, A. simplex sensu stricto (s.s.) and Anisakis pegreffii, that are common in marine fish in Japanese waters. We orally challenged rainbow trout (Oncorhynchus mykiss (Walbaum)), and olive flounder (Paralichthys olivaceus (Temminck and Schlegel)) with L3 larvae of these two sibling species and monitored infection for 5weeks. In rainbow trout, A. simplex s.s., but not A. pegreffii larvae, migrated into the body muscle. A small number of freely moving A. pegreffii larvae were recovered within the body cavity. In olive flounder, A. simplex s.s. larvae were found in both the body cavity and body muscle. A. pegreffii larvae were found only in the body cavity and primarily encapsulated in lumps. Our results indicate that there are differences in the sites of infection and host specificity between the two sibling species of A. simplex s.l. PMID:21122822

  2. Predators of Anopheles gambiae sensu lato (Diptera: Culicidae) Larvae in Wetlands, Western Kenya: Confirmation by Polymerase Chain Reaction Method

    PubMed Central

    OHBA, SHIN-YA; KAWADA, HITOSHI; DIDA, GABRIEL O.; JUMA, DUNCAN; SONYE, GORGE; MINAKAWA, NOBORU; TAKAGI, MASAHIRO

    2010-01-01

    Polymerase chain reaction analysis was performed to determine whether mosquito predators in wetland habitats feed on Anopheles gambiae sensu lato (s.l.) larvae. Aquatic mosquito predators were collected from six wetlands near Lake Victoria in Mbita, Western Kenya. This study revealed that the whole positive rate of An. gambiae s.l. from 330 predators was 54.2%. The order of positive rate was the highest in Odonata (70.2%), followed by Hemiptera (62.8%), Amphibia (41.7%), and Coleoptera (18%). This study demonstrates that the polymerase chain reaction method can determine whether aquatic mosquito predators feed on An. gambiae s.l. larvae if the predators have undigested An. gambiae s.l. in their midgut or stomach. PMID:20939371

  3. Predators of Anopheles gambiae sensu lato (Diptera: Culicidae) larvae in wetlands, western Kenya: confirmation by polymerase chain reaction method.

    PubMed

    Ohba, Shin-Ya; Kawada, Hitoshi; Dida, Gabriel O; Juma, Duncan; Sonye, Gorge; Minakawa, Noboru; Takagi, Masahiro

    2010-09-01

    Polymerase chain reaction analysis was performed to determine whether mosquito predators in wetland habitats feed on Anopheles gambiae sensu lato (s.l.) larvae. Aquatic mosquito predators were collected from six wetlands near Lake Victoria in Mbita, Western Kenya. This study revealed that the whole positive rate of An. gambiae s.l. from 330 predators was 54.2%. The order of positive rate was the highest in Odonata (70.2%), followed by Hemiptera (62.8%), Amphibia (41.7%), and Coleoptera (18%). This study demonstrates that the polymerase chain reaction method can determine whether aquatic mosquito predators feed on An. gambiae s.l. larvae if the predators have undigested An. gambiae s.l. in their midgut or stomach. PMID:20939371

  4. Comparison of Growth of Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi Sensu Stricto at Five Different Temperatures

    PubMed Central

    Veinović, Gorana; Ružić-Sabljić, Eva; Strle, Franc; Cerar, Tjaša

    2016-01-01

    Lyme borreliosis is caused by the spirochete Borrelia burgdorferi sensu lato, a fastidious bacterium that replicates slowly and requires special conditions to grow in the laboratory. Borrelia isolation from clinical material is a golden standard for microbiological diagnosis of borrelial infection. Important factors that affect in vitro borrelia growth are temperature of incubation and number of borrelia cells in the sample. The aim of the study was to assess the influence of temperature on borrelia growth and survival by evaluation and comparison of growth of 31 different borrelia strains at five different temperatures and to determine the influence of different inoculums on borrelia growth at different temperatures. Borreliae were cultured in the MKP medium; the initial and final number of spirochetes was determined by dark field microscopy using Neubauer counting chamber. The growth of borrelia was defined as final number of cells/mL after three days of incubation. For all three Borrelia species, the best growth was found at 33°C, followed by 37, 28, and 23°C, while no growth was detected at 4°C (P<0.05). The growth of B. afzelii species was weaker in comparison to the other two species at 23, 28, 33 and 37°C (P<0.05), respectively. There was no statistically significant difference between the growth of B. garinii and B. burgdorferi sensu stricto at 28, 33, and 37°C (P>0.05), respectively. Inoculum had statistically significant influence on growth of all three Borrelia species at all tested temperatures except at 4°C. PMID:27310556

  5. Comparison of Growth of Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi Sensu Stricto at Five Different Temperatures.

    PubMed

    Veinović, Gorana; Ružić-Sabljić, Eva; Strle, Franc; Cerar, Tjaša

    2016-01-01

    Lyme borreliosis is caused by the spirochete Borrelia burgdorferi sensu lato, a fastidious bacterium that replicates slowly and requires special conditions to grow in the laboratory. Borrelia isolation from clinical material is a golden standard for microbiological diagnosis of borrelial infection. Important factors that affect in vitro borrelia growth are temperature of incubation and number of borrelia cells in the sample. The aim of the study was to assess the influence of temperature on borrelia growth and survival by evaluation and comparison of growth of 31 different borrelia strains at five different temperatures and to determine the influence of different inoculums on borrelia growth at different temperatures. Borreliae were cultured in the MKP medium; the initial and final number of spirochetes was determined by dark field microscopy using Neubauer counting chamber. The growth of borrelia was defined as final number of cells/mL after three days of incubation. For all three Borrelia species, the best growth was found at 33°C, followed by 37, 28, and 23°C, while no growth was detected at 4°C (P<0.05). The growth of B. afzelii species was weaker in comparison to the other two species at 23, 28, 33 and 37°C (P<0.05), respectively. There was no statistically significant difference between the growth of B. garinii and B. burgdorferi sensu stricto at 28, 33, and 37°C (P>0.05), respectively. Inoculum had statistically significant influence on growth of all three Borrelia species at all tested temperatures except at 4°C. PMID:27310556

  6. Echinococcus ortleppi (G5) and Echinococcus granulosus sensu stricto (G1) loads in cattle from Southern Brazil.

    PubMed

    Balbinotti, Helier; Santos, Guilherme B; Badaraco, Jeferson; Arend, Ana C; Graichen, Daniel Ângelo S; Haag, Karen L; Zaha, Arnaldo

    2012-09-10

    Echinococcus granulosus sensu stricto (G1) and Echinococcus ortleppi (G5) are haplotypes of the parasite formerly known as Echinococcus granulosus sensu lato, which in its larval stage causes cystic hydatid disease, endemic in Southern Brazil. Epidemiological and molecular knowledge about the haplotypes occurring in a region is essential to control the spread of the disease. The aim of this work was to analyze the haplotype frequency and fertility of hydatid cysts in cattle from the state of Rio Grande do Sul. Cysts were collected and classified according to their fertility status. DNA was extracted from protoscoleces and germinal layers and then used as template for the amplification of the cytochrome c oxidase subunit 1 gene by PCR. Amplicons were purified and sequenced, and the sequences were analyzed for haplotype identification. A total of 638 fertile cysts collected in the last ten years were genotyped. On average, G1 (56.6%) was more frequent than G5 (43.4%). In lungs, the G5 haplotype exhibited a higher parasite load (52.8%), whereas in the liver, G1 was more frequent (90.4%). The analysis revealed an increase in the frequency of G5 haplotype cysts during the period of sampling, and an increase in the abundance of fertile cysts has also been observed in the last several years. Most infertile cysts were genotyped as G1. The possible factors involved in the increase in the proportion of E. ortleppi (G5) and the consequences of this increase are discussed. This study suggests that the proportion of E. ortleppi (G5) loads in cattle may be increasing overtime. PMID:22571833

  7. Trans-Atlantic exchanges have shaped the population structure of the Lyme disease agent Borrelia burgdorferi sensu stricto

    PubMed Central

    Castillo-Ramírez, S.; Fingerle, V.; Jungnick, S.; Straubinger, R. K.; Krebs, S.; Blum, H.; Meinel, D. M.; Hofmann, H.; Guertler, P.; Sing, A.; Margos, G.

    2016-01-01

    The origin and population structure of Borrelia burgdorferi sensu stricto (s.s.), the agent of Lyme disease, remain obscure. This tick-transmitted bacterial species occurs in both North America and Europe. We sequenced 17 European isolates (representing the most frequently found sequence types in Europe) and compared these with 17 North American strains. We show that trans-Atlantic exchanges have occurred in the evolutionary history of this species and that a European origin of B. burgdorferi s.s. is marginally more likely than a USA origin. The data further suggest that some European human patients may have acquired their infection in North America. We found three distinct genetically differentiated groups: i) the outgroup species Borrelia bissettii, ii) two divergent strains from Europe, and iii) a group composed of strains from both the USA and Europe. Phylogenetic analysis indicated that different genotypes were likely to have been introduced several times into the same area. Our results demonstrate that irrespective of whether B. burgdorferi s.s. originated in Europe or the USA, later trans-Atlantic exchange(s) have occurred and have shaped the population structure of this genospecies. This study clearly shows the utility of next generation sequencing to obtain a better understanding of the phylogeography of this bacterial species. PMID:26955886

  8. Trans-Atlantic exchanges have shaped the population structure of the Lyme disease agent Borrelia burgdorferi sensu stricto.

    PubMed

    Castillo-Ramírez, S; Fingerle, V; Jungnick, S; Straubinger, R K; Krebs, S; Blum, H; Meinel, D M; Hofmann, H; Guertler, P; Sing, A; Margos, G

    2016-01-01

    The origin and population structure of Borrelia burgdorferi sensu stricto (s.s.), the agent of Lyme disease, remain obscure. This tick-transmitted bacterial species occurs in both North America and Europe. We sequenced 17 European isolates (representing the most frequently found sequence types in Europe) and compared these with 17 North American strains. We show that trans-Atlantic exchanges have occurred in the evolutionary history of this species and that a European origin of B. burgdorferi s.s. is marginally more likely than a USA origin. The data further suggest that some European human patients may have acquired their infection in North America. We found three distinct genetically differentiated groups: i) the outgroup species Borrelia bissettii, ii) two divergent strains from Europe, and iii) a group composed of strains from both the USA and Europe. Phylogenetic analysis indicated that different genotypes were likely to have been introduced several times into the same area. Our results demonstrate that irrespective of whether B. burgdorferi s.s. originated in Europe or the USA, later trans-Atlantic exchange(s) have occurred and have shaped the population structure of this genospecies. This study clearly shows the utility of next generation sequencing to obtain a better understanding of the phylogeography of this bacterial species. PMID:26955886

  9. Entomopathogens of Amazonian stick insects and locusts are members of the Beauveria species complex (Cordyceps sensu stricto).

    PubMed

    Sanjuan, Tatiana; Tabima, Javier; Restrepo, Silvia; Læssøe, Thomas; Spatafora, Joseph W; Franco-Molano, Ana Esperanza

    2014-01-01

    In the Amazon the only described species of Cordyceps sensu stricto (Hypocreales, Cordycipitaceae) that parasitize insects of Orthopterida (orders Orthoptera and Phasmida) are Cordyceps locustiphila and C. uleana. However, the type specimens for both taxa have been lost and the concepts of these species are uncertain. To achieve a more comprehensive understanding of the systematics of these species, collections of Cordyceps from the Amazon regions of Colombia, Ecuador and Guyana were subjected to morphological, ecological and molecular phylogenetic studies. Phylogenetic analyses were conducted on partial sequences of SSU, LSU, TEF, RPB1 and RPB2 nuclear loci. Two new species are proposed including C. diapheromeriphila, a parasite of Phasmida, and C. acridophila, a parasite of the superfamily Acridomorpha (Orthoptera), which is broadly distributed across the Amazon. For C. locustiphila a lectotypification and an epitypification are made. Cordyceps locustiphila is host specific with Colpolopha (Acridomorpha: Romaleidae), and its distribution coincides with that of its host. The phylogenetic placement of these three species was resolved with strong support in the Beauveria clade of Cordyceps s. str. (Cordycipitaceae). This relationship and the morphological similarity of their yellow stromata with known teleomorphs of the clade, suggest that the holomorphs of these species may include Beauveria or Beauveria-like anamorphs. The varying host specificity of the beauverioid Cordyceps species suggest the potential importance of identifying the natural host taxon before future consideration of strains for use in biological control of pest locusts. PMID:24782494

  10. Canine echinococcosis: genetic diversity of Echinococcus granulosus sensu stricto (s.s.) from definitive hosts.

    PubMed

    Boufana, B; Lett, W; Lahmar, S; Griffiths, A; Jenkins, D J; Buishi, I; Engliez, S A; Alrefadi, M A; Eljaki, A A; Elmestiri, F M; Reyes, M M; Pointing, S; Al-Hindi, A; Torgerson, P R; Okamoto, M; Craig, P S

    2015-11-01

    Canids, particularly dogs, constitute the major source of cystic echinococcosis (CE) infection to humans, with the majority of cases being caused by Echinococcus granulosus (G1 genotype). Canine echinococcosis is an asymptomatic disease caused by adult tapeworms of E. granulosus sensu lato (s.l.). Information on the population structure and genetic variation of adult E. granulosus is limited. Using sequenced data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) we examined the genetic diversity and population structure of adult tapeworms of E. granulosus (G1 genotype) from canid definitive hosts originating from various geographical regions and compared it to that reported for the larval metacestode stage from sheep and human hosts. Echinococcus granulosus (s.s) was identified from adult tapeworm isolates from Kenya, Libya, Tunisia, Australia, China, Kazakhstan, United Kingdom and Peru, including the first known molecular confirmation from Gaza and the Falkland Islands. Haplotype analysis showed a star-shaped network with a centrally positioned common haplotype previously described for the metacestode stage from sheep and humans, and the neutrality indices indicated population expansion. Low Fst values suggested that populations of adult E. granulosus were not genetically differentiated. Haplotype and nucleotide diversities for E. granulosus isolates from sheep and human origin were twice as high as those reported from canid hosts. This may be related to self-fertilization of E. granulosus and/or to the longevity of the parasite in the respective intermediate and definitive hosts. Improved nuclear single loci are required to investigate the discrepancies in genetic variation seen in this study. PMID:26442707

  11. Investigation of an unrecognized large-scale outbreak of Candida parapsilosis sensu stricto fungaemia in a tertiary-care hospital in China

    PubMed Central

    Wang, He; Zhang, Li; Kudinha, Timothy; Kong, Fanrong; Ma, Xiao-Jun; Chu, Yun-Zhuo; Kang, Mei; Sun, Zi-Yong; Li, Ruo-Yu; Liao, Kang; Lu, Juan; Zou, Gui-Ling; Xiao, Meng; Fan, Xin; Xu, Ying-Chun

    2016-01-01

    A data analysis of yeast collections from the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) programme in 2013 revealed a sudden increase in the proportion of Candida parapsilosis complex isolates (n = 98) in one participating hospital (Hospital H). Out of 443 yeast isolates submitted to the CHIF-NET reference laboratory by Hospital H (2010–2014), 212 (47.9%) were identified as C. parapsilosis sensu stricto by sequencing analysis of the internal transcribed spacer region and D1/D2 domain of the 26S rRNA gene. Among the 212 C. parapsilosis sensu stricto isolates, 176 (83.0%) bloodstream-based isolates and 25 isolates from tip cultures of various vascular catheters from 25 patients with candidaemia, were subjected to microsatellite genotyping, and a phylogenetic relationship analysis was performed for 152 isolates. Among the 152 isolates, 45 genotypes (T01 to T45) were identified, and two prevalent genotypes (63.8%) were found: T15 (n = 74, 48.7%) and T16 (n = 23, 15.1%). These two main clones were confined mainly to three different wards of the hospital, and they persisted for 16–25 months and 12–13 months, respectively. The lack of proper coordination between the clinical microbiology laboratory and infection control staff as part of public health control resulted in the failure to timely identify an outbreak, which led to the wide and long-term dissemination of C. parapsilosis sensu stricto in Hospital H. PMID:27251023

  12. Experimental Infection of Ornithodoros erraticus sensu stricto with Two Portuguese African Swine Fever Virus Strains. Study of Factors Involved in the Dynamics of Infection in Ticks.

    PubMed

    Ribeiro, Rita; Otte, Joachim; Madeira, Sara; Hutchings, Geoff H; Boinas, Fernando

    2015-01-01

    African swine fever (ASF) is a frequently devastating hemorrhagic disease of domestic pigs and wild boar and Ornithodoros erraticus sensu stricto argasid ticks are the only biological vectors of African swine fever virus (ASFV) known to occur in Europe. Recently this disease emerged in Eastern Europe and Russian Federation, showing a huge potential for a rapid spread between countries. There is some risk of re-emergence of ASF in the countries where these ticks exist, that can contribute for the persistence of infection and compromise control measures. In this study we aimed to identify factors that determine the probability of infection and its dynamics in the tick vector Ornithodoros erraticus sensu stricto, with two Portuguese strains of ASFV. Our results suggest that these ticks have a high likelihood of excreting the two haemadsorbing ASF viruses of different host origins and that, in field surveys, the analysis of adults and 5th nymphal stage can provide the best chance of detecting virus infection. The results also indicate that infection of pigs with highly virulent ASF viruses will promote higher rates of infection and a higher likelihood for virus excretion by ticks. Nevertheless, there is also a risk, although lower, that ticks can become infected on pigs that have overcome the acute phase of infection, which was simulated in our study by membrane feeding ticks with low titres of virus. We believe these results can be valuable in designing and interpreting the results of ASF control programmes, and future work can also be undertaken as our dataset is released under open access, to perform studies in risk assessment for ASFV persistence in a region where O. erraticus sensu stricto ticks are present. PMID:26366570

  13. Investigation of an unrecognized large-scale outbreak of Candida parapsilosis sensu stricto fungaemia in a tertiary-care hospital in China.

    PubMed

    Wang, He; Zhang, Li; Kudinha, Timothy; Kong, Fanrong; Ma, Xiao-Jun; Chu, Yun-Zhuo; Kang, Mei; Sun, Zi-Yong; Li, Ruo-Yu; Liao, Kang; Lu, Juan; Zou, Gui-Ling; Xiao, Meng; Fan, Xin; Xu, Ying-Chun

    2016-01-01

    A data analysis of yeast collections from the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) programme in 2013 revealed a sudden increase in the proportion of Candida parapsilosis complex isolates (n = 98) in one participating hospital (Hospital H). Out of 443 yeast isolates submitted to the CHIF-NET reference laboratory by Hospital H (2010-2014), 212 (47.9%) were identified as C. parapsilosis sensu stricto by sequencing analysis of the internal transcribed spacer region and D1/D2 domain of the 26S rRNA gene. Among the 212 C. parapsilosis sensu stricto isolates, 176 (83.0%) bloodstream-based isolates and 25 isolates from tip cultures of various vascular catheters from 25 patients with candidaemia, were subjected to microsatellite genotyping, and a phylogenetic relationship analysis was performed for 152 isolates. Among the 152 isolates, 45 genotypes (T01 to T45) were identified, and two prevalent genotypes (63.8%) were found: T15 (n = 74, 48.7%) and T16 (n = 23, 15.1%). These two main clones were confined mainly to three different wards of the hospital, and they persisted for 16-25 months and 12-13 months, respectively. The lack of proper coordination between the clinical microbiology laboratory and infection control staff as part of public health control resulted in the failure to timely identify an outbreak, which led to the wide and long-term dissemination of C. parapsilosis sensu stricto in Hospital H. PMID:27251023

  14. Experimental Infection of Ornithodoros erraticus sensu stricto with Two Portuguese African Swine Fever Virus Strains. Study of Factors Involved in the Dynamics of Infection in Ticks

    PubMed Central

    Madeira, Sara; Hutchings, Geoff H.; Boinas, Fernando

    2015-01-01

    African swine fever (ASF) is a frequently devastating hemorrhagic disease of domestic pigs and wild boar and Ornithodoros erraticus sensu stricto argasid ticks are the only biological vectors of African swine fever virus (ASFV) known to occur in Europe. Recently this disease emerged in Eastern Europe and Russian Federation, showing a huge potential for a rapid spread between countries. There is some risk of re-emergence of ASF in the countries where these ticks exist, that can contribute for the persistence of infection and compromise control measures. In this study we aimed to identify factors that determine the probability of infection and its dynamics in the tick vector Ornithodoros erraticus sensu stricto, with two Portuguese strains of ASFV. Our results suggest that these ticks have a high likelihood of excreting the two haemadsorbing ASF viruses of different host origins and that, in field surveys, the analysis of adults and 5th nymphal stage can provide the best chance of detecting virus infection. The results also indicate that infection of pigs with highly virulent ASF viruses will promote higher rates of infection and a higher likelihood for virus excretion by ticks. Nevertheless, there is also a risk, although lower, that ticks can become infected on pigs that have overcome the acute phase of infection, which was simulated in our study by membrane feeding ticks with low titres of virus. We believe these results can be valuable in designing and interpreting the results of ASF control programmes, and future work can also be undertaken as our dataset is released under open access, to perform studies in risk assessment for ASFV persistence in a region where O. erraticus sensu stricto ticks are present. PMID:26366570

  15. Studies on the Biology of Hypogeococcus pungens (sensu stricto) (Hemiptera: Pseudococcidae) in Argentina to Aid the Identification of the Mealybug Pest of Cactaceae in Puerto Rico.

    PubMed

    Aguirre, M B; Diaz-Soltero, H; Claps, L E; Saracho Bottero, A; Triapitsyn, S; Hasson, E; Logarzo, G A

    2016-01-01

    Hypogeococcus pungens Granara de Willink, sensu stricto, is a serious pest of cacti in Puerto Rico threating many Caribbean islands. A classical biological control program for H. pungens was initiated for Puerto Rico in 2010 with a survey for natural enemies of H. pungens in its native range of Argentina. Biological differences were observed between populations of H. pungens sampled on Amaranthaceae and Cactaceae. Molecular studies suggested that H. pungens populations from different host plant families are likely a complex of species. Our objective was to study the biology of H. pungens sensu stricto on specimens collected in the same locality and host plant as the holotype [Tucumán Province, Argentina; Alternanthera pungens Kunth (Amaranthaceae)]. We were interested in the reproductive biology of females, longevity and survival of adults, the effect of temperature on the development, and nymph performance (survival and development) on five Cactaceae species. We found that H. pungens s.s showed marked biological differences from the populations collected on Cactaceae and exported to Australia for the biological control of the cactus Harrisia spp. The main differences were the presence of deuterotoky parthenogenesis and the fact that H. pungens did not attack Cactaceae in the laboratory. Our results provide biological evidence that H. pungens is a species complex. We propose that the population introduced to Australia is neither Hypogeococcus festerianus Lizer y Trelles nor H. pungens, but an undescribed species with three circuli, and that the Hypogeococcus pest of cacti in Puerto Rico is not H. pungens. PMID:27324585

  16. Studies on the Biology of Hypogeococcus pungens (sensu stricto) (Hemiptera: Pseudococcidae) in Argentina to Aid the Identification of the Mealybug Pest of Cactaceae in Puerto Rico

    PubMed Central

    Aguirre, M. B.; Diaz-Soltero, H.; Claps, L. E.; Saracho Bottero, A.; Triapitsyn, S.; Hasson, E.; Logarzo, G. A.

    2016-01-01

    Hypogeococcus pungens Granara de Willink, sensu stricto, is a serious pest of cacti in Puerto Rico threating many Caribbean islands. A classical biological control program for H. pungens was initiated for Puerto Rico in 2010 with a survey for natural enemies of H. pungens in its native range of Argentina. Biological differences were observed between populations of H. pungens sampled on Amaranthaceae and Cactaceae. Molecular studies suggested that H. pungens populations from different host plant families are likely a complex of species. Our objective was to study the biology of H. pungens sensu stricto on specimens collected in the same locality and host plant as the holotype [Tucumán Province, Argentina; Alternanthera pungens Kunth (Amaranthaceae)]. We were interested in the reproductive biology of females, longevity and survival of adults, the effect of temperature on the development, and nymph performance (survival and development) on five Cactaceae species. We found that H. pungens s.s. showed marked biological differences from the populations collected on Cactaceae and exported to Australia for the biological control of the cactus Harrisia spp. The main differences were the presence of deuterotoky parthenogenesis and the fact that H. pungens did not attack Cactaceae in the laboratory. Our results provide biological evidence that H. pungens is a species complex. We propose that the population introduced to Australia is neither Hypogeococcus festerianus Lizer y Trelles nor H. pungens, but an undescribed species with three circuli, and that the Hypogeococcus pest of cacti in Puerto Rico is not H. pungens. PMID:27324585

  17. Magma-sediment interactions in the Limagne trench (Massif Central, France): distinction between phreatomagmatic and stricto-sensu peperitic processes

    NASA Astrophysics Data System (ADS)

    Leibrandt, Sebastien; Bénard, Antoine; Brigaud, Benjamin

    2013-04-01

    can solely give birth to the stricto-sensu fluidal to blocky peperite microtexture, which we clearly distinguish for the first time in the Limagne area. A second outcome emerges thanks to the several approaches we use for microscopic characterization, which possibly reveal high-grade, non-explosive mingling of liquefied sediment with magma at the sub-millimetre scale. These observations provide new insights into peperite formation processes in carbonate sediments, when both considering experiments (e.g. Zimanowski and Büttner, 2002) and worldwide field observations in contrasting environments (e.g. McClintock & White, 2002). McClintock, M.K., White, J.D.L., 2002. Granulation of weak rock as a precursor to peperite formation: coal peperite, Coombs Hill, Antartica. Journal of Volcanology and Geothermal Research, 114, 205-217. Skilling, I.P., White, J.D.L., McPhie, J., 2002. Peperite: a review of magma-sediment mingling. Journal of Volcanology and Geothermal Research, 114, 1-17. Zimanowski, B., Büttner, R., 2002. Dynamic mingling of magma and liquefied sediments. Journal of Volcanology and Geothermal Research, 114, 37-44.

  18. Non-destructive Determination of Age and Species of Anopheles gambiae s.l. Using Near-Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of the species and age of malaria vectors is crucial for the measurement of malaria risk. Although different in ecology and susceptibility to control, the African malaria vectors Anopheles gambiae sensu stricto and An. arabiensis are morphologically similar and can be differentiated on...

  19. Survey and first molecular characterization of Echinococcus granulosus sensu stricto (G1) in Pampas fox (Lycalopex gymnocercus) in Buenos Aires province, Argentina.

    PubMed

    Scioscia, Nathalia Paula; Petrigh, Romina Sandra; Beldomenico, Pablo Martín; Fugassa, Martín; Denegri, Guillermo María

    2016-06-01

    Echinococcosis is a zoonosis caused by tapeworms of the genus Echinococcus. Echinococcus granulosus sensu lato (s. l.) has a world-wide distribution and its transmission is primarily maintained in a synanthropic cycle with dogs as definitive hosts and livestock species as intermediate hosts. However, many wild canids also function as definitive hosts for E. granulosus s. l. Echinococcosis in humans is mainly caused by E. granulosus sensu stricto (s. s.) G1 genotype. In the present work, we expanded the epidemiological study on echinococcosis reported cases in Pampas fox (Lycalopex gymnocercus) to provide a prevalence estimate for rural areas of southern Buenos Aires province, Argentina. Ninety-five whole intestines were analyzed using the sedimentation and counting technique with a result of 83 foxes (87.37%) harboring at least one helminth species. E. granulosus s. l. adults were found in one Pampas fox (1.05%). These adult helminthes were E. granulosus s. s. (G1) according to the genotyping analysis of a 450-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. PMID:26892869

  20. Floral structure of Emmotum (Icacinaceae sensu stricto or Emmotaceae), a phylogenetically isolated genus of lamiids with a unique pseudotrimerous gynoecium, bitegmic ovules and monosporangiate thecae

    PubMed Central

    Endress, Peter K.; Rapini, Alessandro

    2014-01-01

    Background and Aims Icacinaceae sensu stricto consist of a group of early branching lineages of lamiids whose relationships are not yet resolved and whose detailed floral morphology is poorly known. The most bizarre flowers occur in Emmotum: the gynoecium has three locules on one side and none on the other. It has been interpreted as consisting of three fertile and two sterile carpels or of one fertile carpel with two longitudinal septa and two sterile carpels. This study focused primarily on the outer and inner morphology of the gynoecium to resolve its disputed structure, and ovule structure was also studied. In addition, the perianth and androecium were investigated. Methods Flowers and floral buds of two Emmotum species, E. harleyi and E. nitens, were collected and fixed in the field, and then studied by scanning electron microscopy. Microtome section series were used to reconstruct their morphology. Key Results The gynoecium in Emmotum was confirmed as pentamerous, consisting of three fertile and two sterile carpels. Each of the three locules behaves as the single locule in other Icacinaceae, with the placenta of the two ovules being identical, which shows that three fertile carpels are present. In addition, it was found that the ovules are bitegmic, which is almost unique in lamiids, and that the stamens have monosporangiate thecae, which also occurs in the closely related family Oncothecaceae, but is not known from any other Icacinaceae sensu lato so far. Conclusions The flowers of Emmotum have unique characters at different evolutionary levels: the pseudotrimerous gynoecium at angiosperm level, the bitegmic ovules at lamiid level and the monosporangiate thecae at family or family group level. However, in general, the floral morphology of Emmotum fits well in Icacinaceae. More comparative research on flower structure is necessary in Icacinaceae and other early branching lineages of lamiids to better understand the initial evolution of this large lineage of

  1. High-resolution melting analysis (HRM) for differentiation of four major Taeniidae species in dogs Taenia hydatigena, Taenia multiceps, Taenia ovis, and Echinococcus granulosus sensu stricto.

    PubMed

    Dehghani, Mansoureh; Mohammadi, Mohammad Ali; Rostami, Sima; Shamsaddini, Saeedeh; Mirbadie, Seyed Reza; Harandi, Majid Fasihi

    2016-07-01

    Tapeworms of the genus Taenia include several species of important parasites with considerable medical and veterinary significance. Accurate identification of these species in dogs is the prerequisite of any prevention and control program. Here, we have applied an efficient method for differentiating four major Taeniid species in dogs, i.e., Taenia hydatigena, T. multiceps, T. ovis, and Echinococcus granulosus sensu stricto. High-resolution melting (HRM) analysis is simpler, less expensive, and faster technique than conventional DNA-based assays and enables us to detect PCR amplicons in a closed system. Metacestode samples were collected from local abattoirs from sheep. All the isolates had already been identified by PCR-sequencing, and their sequence data were deposited in the GenBank. Real-time PCR coupled with HRM analysis targeting mitochondrial cox1 and ITS1 genes was used to differentiate taeniid species. Distinct melting curves were obtained from ITS1 region enabling accurate differentiation of three Taenia species and E. granulosus in dogs. The HRM curves of Taenia species and E .granulosus were clearly separated at Tm of 85 to 87 °C. In addition, double-pick melting curves were produced in mixed infections. Cox1 melting curves were not decisive enough to distinguish four taeniids. In this work, the efficiency of HRM analysis to differentiate four major taeniid species in dogs has been demonstrated using ITS1 gene. PMID:27008188

  2. Coinfection of western gray squirrel (Sciurus griseus) and other sciurid rodents with Borrelia burgdorferi sensu stricto and Anaplasma phagocytophilum in California.

    PubMed

    Nieto, Nathan C; Leonhard, Sarah; Foley, Janet E; Lane, Robert S

    2010-01-01

    Overlapping geographic distributions of tick-borne disease agents utilizing the same tick vectors are common, and coinfection of humans, domestic animals, wildlife, and ticks with both Borrelia burgdorferi and Anaplasma phagocytophilum has been frequently reported. This study was undertaken in order to evaluate the prevalence of both B. burgdorferi sensu stricto (hereinafter referred to as B. burgdorferi) and A. phagocytophilum in several species of sciurid rodents from northern California, USA. Rodents were either collected dead as road-kills or live-trapped in four state parks from 13 counties. Thirty-seven western gray squirrels (Sciurus griseus), nine nonnative eastern gray squirrels (S. carolinensis) and an eastern fox squirrel (S. niger), four Douglas squirrels (Tamiasciurus douglasii), and two northern flying squirrels (Glaucomys sabrinus) were tested by polymerase chain reaction (PCR) and serology for evidence of coinfection. Of the 14 individual S. griseus that were PCR-positive for B. burgdorferi, two (14%) also were PCR-positive for A. phagocytophilum and 11 (79%) had serologic evidence of A. phagocytophilum exposure. Two of the four Douglas squirrels were PCR positive for B. burgdorferi and seropositive to A. phagocytophilum. Evidence of coinfection with these zoonotic pathogens in western gray squirrels suggests that both bacteria may be maintained in a similar transmission cycle involving this sciurid and the western black-legged tick Ixodes pacificus, the primary bridging vector to humans in the far-western US. PMID:20090047

  3. [Susceptibility status of Anopheles gambiae sensu lato to insecticides commonly used for malaria control in Mali].

    PubMed

    Keïta, M; Traoré, S; Sogoba, N; Dicko, A M; Coulibaly, B; Sacko, A; Doumbia, S; Traoré, S F

    2016-02-01

    The objective of this work was to monitor the susceptibility of malaria vectors to insecticides in nine sentinel sites of the National Malaria Control Program in Mali. The study was performed during the rainy seasons of 2010 and 2011. WHO bioassays were conducted using F0 and/or F1 from wild collected females. The insecticides used were lambda-cyhalothrin 0.05%, DDT 4%, permethrin 0.75%, deltamethrin 0.05%, bendiocarb 0.1% and fenitrothion 1.0%. Results showed suspicion of resistance to pyrethroids and organochlorine in An. gambiae s.l. at almost all the sites except Yanfolila where the vector was susceptible to lambda-cyhalothrin (98.0%) [CI 95%, 98-99.8] and to DDT (100%). An. gambiae s.l. was susceptible to bendiocarb in five of the sites (Gao, Bougouni, Djenné, Yanfolila, Tombouctou) while there was a suspicion of resistance at the other sites (Kati, Niono, Bandiagara, Kita). Fenitrothion remains efficient except in the rice area of Niono, where there was a suspicion of resistance with a mortality rate of 92% [IC 95% 88.3-94.8]. Thus, it could be used as an alternative insecticide for IRS in Mali. These results show resistance to pyrethroids, the main insecticide family used in public health (and to some extent in agriculture). This could compromise the malaria vector control efforts in Mali where pyrethroids are used for both in bed nets and in IRS. PMID:26740098

  4. Development of an FgMito assay: A highly sensitive mitochondrial based qPCR assay for quantification of Fusarium graminearum sensu stricto.

    PubMed

    Kulik, Tomasz; Ostrowska, Anna; Buśko, Maciej; Pasquali, Matias; Beyer, Marco; Stenglein, Sebastian; Załuski, Dariusz; Sawicki, Jakub; Treder, Kinga; Perkowski, Juliusz

    2015-10-01

    An ascomycete fungus, Fusarium graminearum sensu stricto (s.s.), is the major cause of Fusarium head blight (FHB), a devastating disease of cereals worldwide. The fungus contaminates crops with mycotoxins, which pose a serious threat to food and feed safety. In this study, we developed a highly sensitive mitochondrial based qPCR assay (FgMito qPCR) for quantification of F. graminearum s.s. To ensure high sensitivity of the assay, primers and a Minor-groove binding (MGB) probe were designed based on multi-copy mitochondrial DNA. The FgMito assay was successfully validated against a range of geographically diverse F. graminearum s.s. strains to ensure uniformity of the assay at an intraspecific level, as well as with other fungal species to ensure specificity. The assay was further evaluated in terms of efficiency and sensitivity against a test panel of different F. graminearum s.s. strains with various levels of pure fungal DNA and in the presence of wheat background DNA. The results showed a high efficiency of the assay developed, ranging from 93% to 101% with r(2)-values of >0.99. We further showed that three low concentrations of fungal template 2 pg, 0.6 pg and 0.2 pg could be reliably quantified in the presence of wheat background DNA. The FgMito assay was used to quantify F. graminearum s.s. DNA on 65 field samples from a range of hosts with defined levels of trichothecenes. We revealed a significant positive correlation between fungal DNA quantity and the sum of trichothecenes. Lastly, we showed a higher sensitivity of the FgMito assay than the nuclear based qPCR assay for F. graminearum s.s. by comparing Ct-values from both assays. PMID:26087129

  5. Performance of Five Food Regimes on Anopheles gambiae Senso Stricto Larval Rearing to Adult Emergence in Insectary

    PubMed Central

    Kivuyo, Happiness S.; Mbazi, Paschal H.; Kisika, Denis S.; Munga, Stephen; Rumisha, Susan F.; Urasa, Felister M.; Kweka, Eliningaya J.

    2014-01-01

    Background Rearing of Anopheles gambiae s.s mosquitoes in insectary with quality cheap food sources is of paramount importance for better and healthy colony. This study evaluated larval survival and the development rate of aquatic stages of An.gambiae s.s under five food regimes; tetramin fish food (a standard insectary larval food), maize pollen, Cerelac, green filamentous algae and dry powdered filamentous algae. Methods Food materials were obtained from different sources, cerelac was made locally, fresh filamentous algae was taken from water bodies, dry filamentous algae was ground to powder after it was dried under shade, and maize pollen was collected from the flowering maize. Each food source type was used to feed three densities of mosquito larvae 20, 60, and 100 in six replicates each. Larval age structure was monitored daily until pupation and subsequently adult emergence. Tetramin was used and taken as a standard food source for An. gambiae s.s. larvae feeding in Insectary. Results Larval survivorship using maize pollen and Tetramin fish food was statistically insignificant (P = 0.564). However when compared to other food regime survivorship was significantly different with Tetramin fish food performing better than cerelac (P<0.001), dry algae (P<0.001) and fresh algae (P<0.001). The pupation rates and sex ratio of emerging adults had significant differences among the food regimes. Conclusion The findings of this study have shown that maize pollen had closely similar nutritional value for larval survivorship to tetramin fish food, a standard larvae food in insectary. Further studies are required to assess the effect of food sources on various life traits of the emerged adults. PMID:25340408

  6. Comparative molecular analyses of Borrelia burgdorferi sensu stricto strains B31 and N40D10/E9 and determination of their pathogenicity

    PubMed Central

    2012-01-01

    Background Lyme disease in the United States is caused primarily by B. burgdorferi sensu stricto while other species are also prevalent in Europe. Genetic techniques have identified several chromosomal and plasmid-borne regulatory and virulence factors involved in Lyme pathogenesis. B31 and N40 are two widely studied strains of B. burgdorferi, which belong to two different 16 S-23 S rRNA spacer types (RST) and outer surface protein C (OspC) allelic groups. However, the presence of several known virulence factors in N40 has not been investigated. This is the first comprehensive study that compared these two strains both in vitro and using the mouse model of infection. Results Phylogenetic analyses predict B31 to be more infectious. However, our studies here indicate that N40D10/E9 is more infectious than the B31 strain at lower doses of inoculation in the susceptible C3H mice. Based-upon a careful analyses of known adhesins of these strains, it is predicted that the absence of a known fibronectin-glycosaminoglycan binding adhesin, bbk32, in the N40 strain could at least partially be responsible for reduction in its binding to Vero cells in vitro. Nevertheless, this difference does not affect the infectivity of N40D10/E9 strain. The genes encoding known regulatory and virulence factors critical for pathogenesis were detected in both strains. Differences in the protein profiles of these B. burgdorferi strains in vitro suggest that the novel, differentially expressed molecules may affect infectivity of B. burgdorferi. Further exacerbation of these molecular differences in vivo could affect the pathogenesis of spirochete strains. Conclusion Based upon the studies here, it can be predicted that N40D10/E9 disseminated infection at lower doses may be enhanced by its lower binding to epithelial cells at the site of inoculation due to the absence of BBK32. We suggest that complete molecular analyses of virulence factors followed by their evaluation using the mouse infection

  7. Dose–response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (Sumilarv®0.5G) for the control of the malaria vectors Anopheles gambiae sensu lato

    PubMed Central

    2013-01-01

    Background Recently research has shown that larviciding can be an effective tool for integrated malaria vector control. Nevertheless, the uptake of this intervention has been hampered by the need to re-apply larvicides frequently. There is a need to explore persistent, environmentally friendly larvicides for malaria vector control to reduce intervention efforts and costs by reducing the frequency of application. In this study, the efficacy of a 0.5% pyriproxyfen granule (Surmilarv®0.5G, Sumitomo Chemicals) was assessed for the control of Anopheles gambiae sensu stricto and Anopheles arabiensis, the major malaria vectors in sub-Saharan Africa. Methods Dose–response and standardized field tests were implemented following standard procedures of the World Health Organization’s Pesticide Evaluation Scheme to determine: (i) the susceptibility of vectors to this formulation; (ii) the residual activity and appropriate retreatment schedule for field application; and, (iii) sub-lethal impacts on the number and viability of eggs laid by adults after exposure to Sumilarv®0.5G during larval development. Results Anopheles gambiae s.s. and An. arabiensis were highly susceptible to Sumilarv®0.5G. Estimated emergence inhibition (EI) values were very low and similar for both species. The minimum dosage that completely inhibited adult emergence was between 0.01-0.03 parts per million (ppm) active ingredient (ai). Compared to the untreated control, an application of 0.018 ppm ai prevented 85% (95% confidence interval (CI) 82%-88%) of adult emergence over six weeks under standardized field conditions. A fivefold increase in dosage of 0.09 ppm ai prevented 97% (95% CI 94%-98%) emergence. Significant sub-lethal effects were observed in the standardized field tests. Female An. gambiae s.s. that were exposed to 0.018 ppm ai as larvae laid 47% less eggs, and females exposed to 0.09 ppm ai laid 74% less eggs than females that were unexposed to the treatment. Furthermore, 77

  8. Review of Apanteles sensu stricto (Hymenoptera, Braconidae, Microgastrinae) from Area de Conservación Guanacaste, northwestern Costa Rica, with keys to all described species from Mesoamerica

    PubMed Central

    Fernández-Triana, Jose L.; Whitfield, James B.; Rodriguez, Josephine J.; Smith, M. Alex; Janzen, Daniel H.; Hallwachs, Winnie D.; Hajibabaei, Mehrdad; Burns, John M.; Solis, M. Alma; Brown, John; Cardinal, Sophie; Goulet, Henri; Hebert, Paul D. N.

    2014-01-01

    Abstract More than half a million specimens of wild-caught Lepidoptera caterpillars have been reared for their parasitoids, identified, and DNA barcoded over a period of 34 years (and ongoing) from Area de Conservación de Guanacaste (ACG), northwestern Costa Rica. This provides the world’s best location-based dataset for studying the taxonomy and host relationships of caterpillar parasitoids. Among Hymenoptera, Microgastrinae (Braconidae) is the most diverse and commonly encountered parasitoid subfamily, with many hundreds of species delineated to date, almost all undescribed. Here, we reassess the limits of the genus Apanteles sensu stricto, describe 186 new species from 3,200+ parasitized caterpillars of hundreds of ACG Lepidoptera species, and provide keys to all 205 described Apanteles from Mesoamerica – including 19 previously described species in addition to the new species. The Mesoamerican Apanteles are assigned to 32 species-groups, all but two of which are newly defined. Taxonomic keys are presented in two formats: traditional dichotomous print versions and links to electronic interactive versions (software Lucid 3.5). Numerous illustrations, computer-generated descriptions, distributional information, wasp biology, and DNA barcodes (where available) are presented for every species. All morphological terms are detailed and linked to the Hymenoptera Anatomy Ontology website. DNA barcodes (a standard fragment of the cytochrome c oxidase I (COI) mitochondrial gene), information on wasp biology (host records, solitary/gregariousness of wasp larvae), ratios of morphological features, and wasp microecological distributions were used to help clarify boundaries between morphologically cryptic species within species-complexes. Because of the high accuracy of host identification for about 80% of the wasp species studied, it was possible to analyze host relationships at a regional level. The ACG species of Apanteles attack mainly species of Hesperiidae

  9. The Rare ospC Allele L of Borrelia burgdorferi Sensu Stricto, Commonly Found among Samples Collected in a Coastal Plain Area of the Southeastern United States, Is Associated with Ixodes affinis Ticks and Local Rodent Hosts Peromyscus gossypinus and Sigmodon hispidus

    PubMed Central

    Golovchenko, Maryna; Grubhoffer, Libor; Oliver, James H.

    2013-01-01

    The rare ospC allele L was detected in 30% of Borrelia burgdorferi sensu stricto strains cultured from a tick species, Ixodes affinis, and two rodent host species, Peromyscus gossypinus and Sigmodon hispidus, collected in a coastal plain area of Georgia and South Carolina, in the southeastern United States. PMID:23220965

  10. PCR assay for identification of Anopheles quadriannulatus species B from Ethiopia and other sibling species of the Anopheles gambiae complex.

    PubMed

    Fettene, M; Koekemoer, L L; Hunt, R H; Coetzee, M

    2002-06-01

    Sibling species A and B of Anopheles quadriannulatus (Theobald) are recognized as allopatric members of the Anopheles gambiae Giles complex of Afrotropical mosquitoes (Diptera: Culicidae). Species A represents An. quadriannulatus sensu stricto, widespread in southern Africa, whereas An. quadriannulatus species B occurs in Ethiopia. Because of difficulty of identification, distribution of An. quadriannulatus sensu lato remains poorly known. Cytotaxonomy and the standard DNA polymerase chain reaction (PCR) assay do not distinguish between species A and B of An. quadriannulatus. By optimizing the standard PCR assay (Scott et al., 1993) for identification of members of the An. gambiae complex, we identified two discriminant fragments of 153 bp and 900 bp from DNA of An. quadriannulatus species B, whereas only the 153 bp fragment was amplified for species A from South Africa. This modified PCR assay can therefore be used to distinguish between species A and B of An. quadriannulatus s.l. as well as other members of the An. gambiae complex. PMID:12109717

  11. Nitrate affects sensu-stricto germination of after-ripened Sisymbrium officinale seeds by modifying expression of SoNCED5, SoCYP707A2 and SoGA3ox2 genes.

    PubMed

    Carrillo-Barral, Néstor; Matilla, Angel J; Rodríguez-Gacio, María del Carmen; Iglesias-Fernández, Raquel

    2014-03-01

    The influence of nitrate upon the germination of Sisymbrium officinale seeds is not entirely controlled by after-ripening (AR), a process clearly influenced by nitrate. Recently, we have reported that nitrate affects sensu-stricto germination of non-AR (AR0) seeds by modifying the expression of crucial genes involved in the metabolism of GA and ABA. In this study, we demonstrate that nitrate affects also the germination of AR seeds because: (i) the AR negatively alters the ABA sensitivity being the seed more ABA-sensible as the AR is farthest from optimal (AR0 and AR20 versus AR7); in the presence of diniconazole (DZ), a competitive inhibitor of ABA 8'-hydroxylase, testa rupture is affected while the endosperm rupture is not. (ii) AR7 seed-coat rupture is not inhibited by paclobutrazol (PBZ) suggesting that nitrate can act by a mechanism GA-independent. (iii) The germination process is accelerated by nitrate, most probably by the increase in the expression of SoNCED5, SoCYP707A2 and SoGA3ox2 genes. Taken together, these and previous results demonstrate that nitrate promotes germination of AR and non-AR seeds through transcriptional changes of different genes involved in ABA and GA metabolism. PMID:24467901

  12. Detection of Borrelia burgdorferi Sensu Stricto ospC Alleles Associated with Human Lyme Borreliosis Worldwide in Non-Human-Biting Tick Ixodes affinis and Rodent Hosts in Southeastern United States

    PubMed Central

    Golovchenko, Maryna; Hönig, Václav; Mallátová, Nadja; Krbková, Lenka; Mikulášek, Peter; Fedorova, Natalia; Belfiore, Natalia M.; Grubhoffer, Libor; Lane, Robert S.; Oliver, James H.

    2013-01-01

    Comparative analysis of ospC genes from 127 Borrelia burgdorferi sensu stricto strains collected in European and North American regions where Lyme disease is endemic and where it is not endemic revealed a close relatedness of geographically distinct populations. ospC alleles A, B, and L were detected on both continents in vectors and hosts, including humans. Six ospC alleles, A, B, L, Q, R, and V, were prevalent in Europe; 4 of them were detected in samples of human origin. Ten ospC alleles, A, B, D, E3, F, G, H, H3, I3, and M, were identified in the far-western United States. Four ospC alleles, B, G, H, and L, were abundant in the southeastern United States. Here we present the first expanded analysis of ospC alleles of B. burgdorferi strains from the southeastern United States with respect to their relatedness to strains from other North American and European localities. We demonstrate that ospC genotypes commonly associated with human Lyme disease in European and North American regions where the disease is endemic were detected in B. burgdorferi strains isolated from the non-human-biting tick Ixodes affinis and rodent hosts in the southeastern United States. We discovered that some ospC alleles previously known only from Europe are widely distributed in the southeastern United States, a finding that confirms the hypothesis of transoceanic migration of Borrelia species. PMID:23263953

  13. Resting behaviour of Anopheles gambiae s.l. and its implication on malaria transmission in Uyui District, western Tanzania.

    PubMed

    Sindato, Calvin; Kabula, Bilali; Mbilu, Togolai J N K; Manga, Chacha; Tungu, Patrick; Kazimoto, John P; Kibonai, Stafford N; Kisinza, William N; Magesa, Stephen M

    2011-10-01

    An entomological survey to determine resting behaviour and species composition of malaria vectors was carried out in Uyui District in western Tanzania in May 2009. Mosquitoes were collected using indoor resting catch, window exit trap and outdoor "bed-net" techniques. The mosquitoes were identified using morphological key and polymerase chain reaction (PCR). A total of 672 Anopheles gambiae sensu lato were collected. Of these, 661 (98.4%) were collected outdoor whereas few (1.6%) were collected indoor. The exit trap catch: mechanical aspirator catch ratio was 1:1.75. The overall indoor resting density of An. gambiae s.l. as determined by mechanical aspirator and exit trap was 0.7 and 0.5 mosquitoes per room, respectively. The overall density of the host-seeking as determined by bed net trap outdoor was 44.1 mosquitoes per person. A sample of 44 specimens taken randomly from morphologically identified An.gambiae s.l. population was further analyzed to species level using PCR techniques. Of these 44 specimens 26 (59%) and 18 (41%) were Anopheles arabiensis and Anopheles gambiae sensu stricto respectively. This study contributes to the understanding of the distribution of malaria vectors with respect to species composition and their resting behaviour that could contribute to vector control operations in western Tanzania. A longitudinal study considering dry and wet seasons is recommended to provide more information on the seasonal distribution, abundance and biting behaviour of malaria vectors in the study area. PMID:26592058

  14. Co-occurrence and distribution of East (L1014S) and West (L1014F) African knock-down resistance in Anopheles gambiae sensu lato population of Tanzania

    PubMed Central

    Kabula, Bilali; Kisinza, William; Tungu, Patrick; Ndege, Chacha; Batengana, Benard; Kollo, Douglas; Malima, Robert; Kafuko, Jessica; Mohamed, Mahdi; Magesa, Stephen

    2014-01-01

    Objective Insecticide resistance molecular markers can provide sensitive indicators of resistance development in Anopheles vector populations. Assaying these makers is of paramount importance in the resistance monitoring programme. We investigated the presence and distribution of knock-down resistance (kdr) mutations in Anopheles gambiae s.l. in Tanzania. Methods Indoor-resting Anopheles mosquitoes were collected from 10 sites and tested for insecticide resistance using the standard WHO protocol. Polymerase chain reaction-based molecular diagnostics were used to genotype mosquitoes and detect kdr mutations. Results The An. gambiae tested were resistance to lambdacyhalothrin in Muheza, Arumeru and Muleba. Out of 350 An. gambiae s.l. genotyped, 35% were An. gambiae s.s. and 65% An. arabiensis. L1014S and L1014F mutations were detected in both An. gambiae s.s. and An. arabiensis. L1014S point mutation was found at the allelic frequency of 4–33%, while L1014F was at the allelic frequency 6–41%. The L1014S mutation was much associated with An. gambiae s.s. (χ2 = 23.41; P < 0.0001) and L1014F associated with An. arabiensis (χ2 = 11.21; P = 0.0008). The occurrence of the L1014S allele was significantly associated with lambdacyhalothrin resistance mosquitoes (Fisher exact P < 0.001). Conclusion The observed co-occurrence of L1014S and L1014F mutations coupled with reports of insecticide resistance in the country suggest that pyrethroid resistance is becoming a widespread phenomenon among our malaria vector populations. The presence of L1014F mutation in this East African mosquito population indicates the spreading of this gene across Africa. The potential operational implications of these findings on malaria control need further exploration. Objectif Les marqueurs moléculaires de la résistance aux insecticides peuvent fournir des indicateurs sensibles du développement de la résistance dans les populations de vecteurs Anopheles. Le test de ces

  15. Application of a biochemical key to study transmission of malaria and Bancroftian filariasis in sibling species of the Anopheles gambiae complex in north-eastern Tanzania.

    PubMed

    Mnzava, A E; Kilama, W L; Kasigwa, P F

    1989-10-01

    A biochemical key was applied in order to study transmission of malaria and Bancroftian filariasis in Anopheles gambiae sensu stricto, An. arabiensis and An. merus in different localities in north-eastern Tanzania. The technique was found to be a useful additional taxonomic tool for field entomologists. Significant differences between species in the rate of infection with Bancroftian filariasis were obtained between An. gambiae s.s. and An. funestus (P less than 0.005) and between An. funestus and An. arabiensis (P less than 0.0001). There were also significant differences between most of the investigated localities in the rate of filarial infection. However, there were no significant differences between the three species or between localities with respect to malaria sporozoite rates. Possible reasons for the observed variation between species and localities with respect to vectorial activity for Bancroftian filariasis are discussed. PMID:2575868

  16. Breakdown in the Process of Incipient Speciation in Anopheles gambiae

    PubMed Central

    Nwakanma, Davis C.; Neafsey, Daniel E.; Jawara, Musa; Adiamoh, Majidah; Lund, Emily; Rodrigues, Amabelia; Loua, Kovana M.; Konate, Lassana; Sy, Ngayo; Dia, Ibrahima; Awolola, T. Samson; Muskavitch, Marc A. T.; Conway, David J.

    2013-01-01

    Understanding genetic causes and effects of speciation in sympatric populations of sexually reproducing eukaryotes is challenging, controversial, and of practical importance for controlling rapidly evolving pests and pathogens. The major African malaria vector mosquito Anopheles gambiae sensu stricto (s.s.) is considered to contain two incipient species with strong reproductive isolation, hybrids between the M and S molecular forms being very rare. Following recent observations of higher proportions of hybrid forms at a few sites in West Africa, we conducted new surveys of 12 sites in four contiguous countries (The Gambia, Senegal, Guinea-Bissau, and Republic of Guinea). Identification and genotyping of 3499 A. gambiae s.s. revealed high frequencies of M/S hybrid forms at each site, ranging from 5 to 42%, and a large spectrum of inbreeding coefficient values from 0.11 to 0.76, spanning most of the range expected between the alternative extremes of panmixia and assortative mating. Year-round sampling over 2 years at one of the sites in The Gambia showed that M/S hybrid forms had similar relative frequencies throughout periods of marked seasonal variation in mosquito breeding and abundance. Genome-wide scans with an Affymetrix high-density single-nucleotide polymorphism (SNP) microarray enabled replicate comparisons of pools of different molecular forms, in three separate populations. These showed strong differentiation between M and S forms only in the pericentromeric region of the X chromosome that contains the molecular form-specific marker locus, with only a few other loci showing minor differences. In the X chromosome, the M/S hybrid forms were more differentiated from M than from S forms, supporting a hypothesis of asymmetric introgression and backcrossing. PMID:23335339

  17. Equivalent susceptibility of Anopheles gambiae M and S molecular forms and Anopheles arabiensis to Plasmodium falciparum infection in Burkina Faso

    PubMed Central

    2013-01-01

    Background The Anopheles gambiae sensu lato (s.l.) species complex in Burkina Faso consists of Anopheles arabiensis, and molecular forms M and S of Anopheles gambiae sensu stricto (s.s.). Previous studies comparing the M and S forms for level of infection with Plasmodium falciparum have yielded conflicting results. Methods Mosquito larvae were sampled from natural pools, reared to adulthood under controlled conditions, and challenged with natural P. falciparum by experimental feeding with blood from gametocyte carriers. Oocyst infection prevalence and intensity was determined one week after infection. DNA from carcasses was genotyped to identify species and molecular form. Results In total, 7,400 adult mosquitoes grown from wild-caught larvae were challenged with gametocytes in 29 experimental infections spanning four transmission seasons. The overall infection prevalence averaged 40.7% for A. gambiae M form, 41.4% for A. gambiae S form, and 40.1% for A. arabiensis. There was no significant difference in infection prevalence or intensity between the three population groups. Notably, infection experiments in which the population groups were challenged in parallel on the same infective blood displayed less infection difference between population groups, while infections with less balanced composition of population groups had lower statistical power and displayed apparent differences that fluctuated more often from the null average. Conclusion The study clearly establishes that, at the study site in Burkina Faso, there is no difference in genetic susceptibility to P. falciparum infection between three sympatric population groups of the A. gambiae s.l. complex. Feeding the mosquito groups on the same infective blood meal greatly increases statistical power. Conversely, comparison of the different mosquito groups between, rather than within, infections yields larger apparent difference between mosquito groups, resulting from lower statistical power and greater noise

  18. Taxonomy and distribution pattern of the African rain forest butterfly genus Euphaedra Hübner sensu stricto with the description of three new subspecies of Euphaedra cyparissa (Cramer) and one of E. sarcoptera (Butler) (Lepidoptera, Nymphalidae, Limenitidinae, Adoliadini)

    PubMed Central

    Pyrcz, Tomasz W.; Warren-Gash, Haydon; Lorenc-Brudecka, Jadwiga; Dieuwko Knoop; Oremans, Philippe; Sáfián, Szabolcs

    2013-01-01

    Abstract Updated data on the distribution, ecology and taxonomy of Euphaedra cyparissa (Cramer) and Euphaedra sarcoptera (Butler) are presented. Three new subspecies of Euphaedra cyparissa and one of Euphaedra sarcoptera are described and their geographic distribution is presented. The monophyly of the genus Euphaedra sensu Hecq is assessed based on morphological, in particular male and female genitalia, and behavioural traits. Possible evolutionary reasons for the convergence of colour pattern between the sympatric subspecies of Euphaedra cyparissa and Euphaedra sarcoptera are discussed. PMID:23794883

  19. Electroantennogram and behavioural responses of the malaria vector Anopheles gambiae to human-specific sweat components.

    PubMed

    Costantini, C; Birkett, M A; Gibson, G; Ziesmann, J; Sagnon, N F; Mohammed, H A; Coluzzi, M; Pickett, J A

    2001-09-01

    Afrotropical malaria vectors of the Anopheles gambiae complex (Diptera: Culicidae), particularly An. gambiae sensu stricto, are attracted mainly to human hosts. A major source of human volatile emissions is sweat, from which key human-specific components are the carboxylic acids (E)- and (Z)-3-methyl-2-hexenoic acid and 7-octenoic acid. Electrophysiological studies on the antennae of An. gambiae s.s. showed selective sensitivity to these compounds, with a threshold at 10(-6) g comparable to that of known olfactory stimulants 1-octen-3-ol, p-cresol, isovaleric acid, and lower than threshold sensitivity to L-lactic acid and the synthetic mosquito repellent N,N-diethyltoluamide (DEET). A combination of the acids released at concentrations > 10(-5) g in wind tunnel bioassays significantly reduced the response to CO2, the major attractant released by human hosts, for strains of An. gambiae s.s. originating from East and West Africa. Field trials with odour-baited entry traps (OBETs) in Burkina Faso showed that 7-octenoic acid significantly increased (by 1.7-fold) the catch of females of An. gambiae sensu lato (comprising two sibling species: An. arabiensis Patton and An. gambiae s.s.) in OBETs baited with CO2, whereas combinations of the acids significantly reduced the catch in CO2-baited traps (by 2.1-fold) and in whole human odour-baited traps (by 1.5-fold). The pure (E) and (Z) geometric isomers of 3-methyl-2-hexenoic acid gave comparable results to the (EIZ) isomer mixture. These results provide the first experimental evidence that human-specific compounds affect the behaviour of highly anthropophilic An. gambiae s.l. mosquitoes. The compounds appear to inhibit the upwind flight' response to known long-range attractants, and may serve either to mask' the attractants present or, more probably, to 'arrest' upwind flight when mosquitoes arrive at a host under natural conditions. In the final approach to hosts, vectors are known to reduce their flight speed and increase

  20. Insecticide resistance in Anopheles gambiae from south-western Chad, Central Africa

    PubMed Central

    Kerah-Hinzoumbé, Clément; Péka, Mallaye; Nwane, Philippe; Donan-Gouni, Issa; Etang, Josiane; Samè-Ekobo, Albert; Simard, Frédéric

    2008-01-01

    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. Conclusion This first

  1. Modelling Anopheles gambiae s.s. Population Dynamics with Temperature- and Age-Dependent Survival.

    PubMed

    Christiansen-Jucht, Céline; Erguler, Kamil; Shek, Chee Yan; Basáñez, María-Gloria; Parham, Paul E

    2015-06-01

    Climate change and global warming are emerging as important threats to human health, particularly through the potential increase in vector- and water-borne diseases. Environmental variables are known to affect substantially the population dynamics and abundance of the poikilothermic vectors of disease, but the exact extent of this sensitivity is not well established. Focusing on malaria and its main vector in Africa, Anopheles gambiae sensu stricto, we present a set of novel mathematical models of climate-driven mosquito population dynamics motivated by experimental data suggesting that in An. gambiae, mortality is temperature and age dependent. We compared the performance of these models to that of a "standard" model ignoring age dependence. We used a longitudinal dataset of vector abundance over 36 months in sub-Saharan Africa for comparison between models that incorporate age dependence and one that does not, and observe that age-dependent models consistently fitted the data better than the reference model. This highlights that including age dependence in the vector component of mosquito-borne disease models may be important to predict more reliably disease transmission dynamics. Further data and studies are needed to enable improved fitting, leading to more accurate and informative model predictions for the An. gambiae malaria vector as well as for other disease vectors. PMID:26030468

  2. Modelling Anopheles gambiae s.s. Population Dynamics with Temperature- and Age-Dependent Survival

    PubMed Central

    Christiansen-Jucht, Céline; Erguler, Kamil; Shek, Chee Yan; Basáñez, María-Gloria; Parham, Paul E.

    2015-01-01

    Climate change and global warming are emerging as important threats to human health, particularly through the potential increase in vector- and water-borne diseases. Environmental variables are known to affect substantially the population dynamics and abundance of the poikilothermic vectors of disease, but the exact extent of this sensitivity is not well established. Focusing on malaria and its main vector in Africa, Anopheles gambiae sensu stricto, we present a set of novel mathematical models of climate-driven mosquito population dynamics motivated by experimental data suggesting that in An. gambiae, mortality is temperature and age dependent. We compared the performance of these models to that of a “standard” model ignoring age dependence. We used a longitudinal dataset of vector abundance over 36 months in sub-Saharan Africa for comparison between models that incorporate age dependence and one that does not, and observe that age-dependent models consistently fitted the data better than the reference model. This highlights that including age dependence in the vector component of mosquito-borne disease models may be important to predict more reliably disease transmission dynamics. Further data and studies are needed to enable improved fitting, leading to more accurate and informative model predictions for the An. gambiae malaria vector as well as for other disease vectors. PMID:26030468

  3. Gene Flow–Dependent Genomic Divergence between Anopheles gambiae M and S Forms

    PubMed Central

    Weetman, David; Wilding, Craig S.; Steen, Keith; Pinto, João; Donnelly, Martin J.

    2012-01-01

    Anopheles gambiae sensu stricto exists as two often-sympatric races termed the M and S molecular forms, characterized by fixed differences at an X-linked marker. Extreme divergence between M and S forms at pericentromeric “genomic islands” suggested that selection on variants therein could be driving interform divergence in the presence of ongoing gene flow, but recent work has detected much more widespread genomic differentiation. Whether such genomic islands are important in reproductive isolation or represent ancestral differentiation preserved by low recombination is currently unclear. A critical test of these competing hypotheses could be provided by comparing genomic divergence when rates of recent introgression vary. We genotyped 871 single nucleotide polymorphisms (SNPs) in A. gambiae sensu stricto from locations of M and S sympatry and allopatry, encompassing the full range of observed hybridization rates (0–25%). M and S forms were readily partitioned based on genomewide SNP variation in spite of evidence for ongoing introgression that qualitatively reflects hybridization rates. Yet both the level and the heterogeneity of genomic divergence varied markedly in line with levels of introgression. A few genomic regions of differentiation between M and S were common to each sampling location, the most pronounced being two centromere–proximal speciation islands identified previously but with at least one additional region outside of areas expected to exhibit reduced recombination. Our results demonstrate that extreme divergence at genomic islands does not simply represent segregating ancestral polymorphism in regions of low recombination and can be resilient to substantial gene flow. This highlights the potential for islands comprising a relatively small fraction of the genome to play an important role in early-stage speciation when reproductive isolation is limited. PMID:21836185

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

    PubMed Central

    Koenraadt, Constantianus JM; Paaijmans, Krijn P; Githeko, Andrew K; Knols, Bart GJ; Takken, Willem

    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, which consisted of trays filled with damp soil. Experiments were performed in these trays to (i) test the ability of An. gambiae sensu stricto eggs to hatch on damp soil and for larvae to reach an artificial breeding site at different distances of the site of hatching and (ii) to record survival of the four larval stages of An. gambiae s.s. when placed on damp soil. Results Eggs of An. gambiae s.s. hatched on damp soil and emerging larvae were capable of covering a distance of up to 10 cm to reach surface water enabling further development. However, proportions of larvae reaching the site decreased rapidly with increasing distance. First, second and third-instar larvae survived on damp soil for an estimated period of 64, 65 and 69 hrs, respectively. Fourth-instar larvae survived significantly longer and we estimated that the maximum survival time was 113 hrs. Conclusion Short-term survival of aquatic stages of An. gambiae on wet soil may be important and adaptive when considering the transient nature of breeding sites of this species in sub-Saharan Africa. In addition, the results suggest that, for larval vector control methods to be effective, habitats should remain drained for at least 5 days to kill all larvae (e.g. in rice fields) and habitats that recently dried up should be treated as well, if larvicidal agents are applied. PMID:12919636

  5. Variation in metabolic rate of Anopheles gambiae and A. arabiensis in a Sahelian village.

    PubMed

    Huestis, Diana L; Yaro, Alpha S; Traoré, Adama I; Adamou, Abdoulaye; Kassogué, Yaya; Diallo, Moussa; Timbiné, Seydou; Dao, Adama; Lehmann, Tovi

    2011-07-15

    In the Sahel, the Anopheles gambiae complex consists of Anopheles arabiensis and the M and S molecular forms of A. gambiae sensu stricto. However, the composition of these malaria vectors varies spatially and temporally throughout the region and is thought to be linked to environmental factors such as rainfall, larval site characteristics and duration of the dry season. To examine possible physiological divergence between these taxa, we measured metabolic rates of mosquitoes during the wet season in a Sahelian village in Mali. To our knowledge, this study provides the first measurements of metabolic rates of A. gambiae and A. arabiensis in the field. The mean metabolic rate of A. arabiensis was higher than that of M-form A. gambiae when accounting for the effects of female gonotrophic status, temperature and flight activity. However, after accounting for their difference in body size, no significant difference in metabolic rate was found between these two species (whilst all other factors were found to be significant). Thus, body size may be a key character that has diverged in response to ecological differences between these two species. Alternatively, these species may display additional differences in metabolic rate only during the dry season. Overall, our results indicate that changes in behavior and feeding activity provide an effective mechanism for mosquitoes to reduce their metabolic rate, and provide insight into the possible strategies employed by aestivating individuals during the dry season. We hypothesize that female mosquitoes switch to sugar feeding while in dormancy because of elevated metabolism associated with blood digestion. PMID:21697426

  6. Variation in metabolic rate of Anopheles gambiae and A. arabiensis in a Sahelian village

    PubMed Central

    Huestis, Diana L.; Yaro, Alpha S.; Traoré, Adama I.; Adamou, Abdoulaye; Kassogué, Yaya; Diallo, Moussa; Timbiné, Seydou; Dao, Adama; Lehmann, Tovi

    2011-01-01

    SUMMARY In the Sahel, the Anopheles gambiae complex consists of Anopheles arabiensis and the M and S molecular forms of A. gambiae sensu stricto. However, the composition of these malaria vectors varies spatially and temporally throughout the region and is thought to be linked to environmental factors such as rainfall, larval site characteristics and duration of the dry season. To examine possible physiological divergence between these taxa, we measured metabolic rates of mosquitoes during the wet season in a Sahelian village in Mali. To our knowledge, this study provides the first measurements of metabolic rates of A. gambiae and A. arabiensis in the field. The mean metabolic rate of A. arabiensis was higher than that of M-form A. gambiae when accounting for the effects of female gonotrophic status, temperature and flight activity. However, after accounting for their difference in body size, no significant difference in metabolic rate was found between these two species (whilst all other factors were found to be significant). Thus, body size may be a key character that has diverged in response to ecological differences between these two species. Alternatively, these species may display additional differences in metabolic rate only during the dry season. Overall, our results indicate that changes in behavior and feeding activity provide an effective mechanism for mosquitoes to reduce their metabolic rate, and provide insight into the possible strategies employed by aestivating individuals during the dry season. We hypothesize that female mosquitoes switch to sugar feeding while in dormancy because of elevated metabolism associated with blood digestion. PMID:21697426

  7. Landing responses of Anopheles gambiae elicited by oxocarboxylic acids.

    PubMed

    Healy, T P; Copland, M J W; Cork, A; Przyborowska, A; Halket, J M

    2002-06-01

    A wind tunnel bioassay and video system were used to observe Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) landing on glass cylinders, heated to human skin temperature (34 degrees C) and treated with aqueous solutions of oxocarboxylic acids. Six of nine compounds tested: 2-oxobutanoic, 2-oxo-3-methylbutanoic, 2-oxopentanoic, 2-oxo-3-methylpentanoic, 2-oxo-4-methylpentanoic and 2-oxohexanoic elicited significant landing responses in comparison to a water control. Landing responses appeared to be restricted to C4-C6, 2-oxocarboxylic acids. A solution of 1 microg/microL of 2-oxopentanoic acid elicited the highest level of response that was temperature dependent: significant numbers of landings occurred only within +/-2 degrees C of human skin temperature. Chemical analysis by linked gas-liquid chromatography/mass spectrometry of methyl-oxime, trimethylsilyl derivatized samples of human sweat extracts revealed the presence of 2-oxopropanoic (pyruvic) acid and three behaviourally active, branched chain acids: 2-oxo-3-methylbutanoic, 2-oxo-3-methylpentanoic and 2-oxo-4-methylpentanoic. PMID:12109705

  8. Sampling of An.gambiae s.s mosquitoes using Limburger cheese, heat and moisture as baits in a homemade trap

    PubMed Central

    2011-01-01

    Background Ample evidence has shown that odour baited traps are likely to provide an objective monitoring tool for the host-seeking fraction of mosquito vectors of diseases like malaria and bancroftian filariasis. Such traps could eventually become part of primary healthcare systems used to study the vector biology and epidemiology of mosquito-borne diseases. I hereby, report a study that sampled Anopheles gambiae sensu stricto mosquitoes in a screen house using a homemade trap baited with a combination of Limburger cheese and moisture, Limburger cheese and heat, or Limburger cheese, moisture and heat. Findings Tests on the efficacy of the developed trap to sample An. gambiae s.s, mosquitoes using Limburger cheese, moisture and heat as baits were carried out in a screen house measuring 11.4 × 7.1 × 2.8 m. The studies were done in three phases. In the first phase the efficacy of the trap to sample An. gambiae s.s. using odour and moisture was tested. The second phase was to test the efficacy of the trap to sample An. gambiae s.s. using Limburger cheese and heat. In the third phase a combination of Limburger cheese, moisture and heat was tested. Tests were carried out for 27 consecutive nights. The designed trap collected a total of 59 An. gambiae s.s. in three trials. The trap baited with Limburger cheese and moisture collected 7 An. gambiae s.s in 7 days. The mean catch per day was 1. The trap baited with Limburger cheese and heat collected zero An. gambiae s.s in 11 days. The mean catch per day was therefore 0. The trap baited with Limburger cheese, moisture and heat collected 52 mosquitoes in 27 days and the mean catch was 1.93. Conclusions This study indicates that a non-electric fan driven trap baited with a combination of Limburger cheese, heat and moisture has a potential as an effective sampling tool for the malaria vector, Anopheles gambiae s.s. However, further optimization studies would be necessary. PMID:21835032

  9. The Gambia.

    PubMed

    1982-11-01

    Attention in this discussion of the Republic of the Gambia is directed to the following: the people; geography; history; government and political conditions; economy; foreign relations; and relations between the US and Gambia. In 1980 Gambia's population was estimated to be 619,052; the 1980-81 annual growth rate estimate was 2.8%. The infant mortality rate is 217/1000; life expectancy is 32 years for men and 34 years for women. Almost 85% of the population live in rural areas. The principal ethnic groups are Mandinka, Fula, Wolof, Jola, and Serahuli, English is the official language, although most Gambians speak their native language. The Gambia, located on the bulge of West Africa, is low lying, with a maximum altitude of 73 meters above sea level. From what is known of its early history, the Gambia was once part of the Empire of Ghana and the Kingdom of the Songhais. By the 16th century, Portuguese slave traders and gold seekers had settled in the lower river area. During the late 17th and throughout the 18th century, England and France struggled continously for political and commercial supremacy in the regions of the Senegal and Gambia rivers. The Gambia achieved independence on February 18, 1965, as a constitutional monarchy within the British Commonwealth. Shortly thereafter the government proposed conversion from a monarchy to a republic with an elected president replacing the British monarch as chief of state. In 1970 a referendum was approved by the required majority, and the Gambia became a republic on April 24th. The government is divided into independent executive, legislative, and judicial branches. Executive power is vested in a president, popularly elected for a 5 year term. The Gambia is 1 of the few African countries with a genuine multiparty system. There is no army. The economy is almost totally agricultural. The small manfacturing sector accounts for about 5% of the gross domestic product. Few foreign investors have taken advantage of the

  10. Insecticide resistance mechanisms associated with different environments in the malaria vector Anopheles gambiae: a case study in Tanzania

    PubMed Central

    2014-01-01

    Background Resistance of mosquitoes to insecticides is a growing concern in Africa. Since only a few insecticides are used for public health and limited development of new molecules is expected in the next decade, maintaining the efficacy of control programmes mostly relies on resistance management strategies. Developing such strategies requires a deep understanding of factors influencing resistance together with characterizing the mechanisms involved. Among factors likely to influence insecticide resistance in mosquitoes, agriculture and urbanization have been implicated but rarely studied in detail. The present study aimed at comparing insecticide resistance levels and associated mechanisms across multiple Anopheles gambiae sensu lato populations from different environments. Methods Nine populations were sampled in three areas of Tanzania showing contrasting agriculture activity, urbanization and usage of insecticides for vector control. Insecticide resistance levels were measured in larvae and adults through bioassays with deltamethrin, DDT and bendiocarb. The distribution of An. gambiae sub-species and pyrethroid target-site mutations (kdr) were investigated using molecular assays. A microarray approach was used for identifying transcription level variations associated to different environments and insecticide resistance. Results Elevated resistance levels to deltamethrin and DDT were identified in agriculture and urban areas as compared to the susceptible strain Kisumu. A significant correlation was found between adult deltamethrin resistance and agriculture activity. The subspecies Anopheles arabiensis was predominant with only few An. gambiae sensu stricto identified in the urban area of Dar es Salaam. The L1014S kdr mutation was detected at elevated frequency in An gambiae s.s. in the urban area but remains sporadic in An. arabiensis specimens. Microarrays identified 416 transcripts differentially expressed in any area versus the susceptible reference

  11. Combining two-dimensional gel electrophoresis and metabolomic data in support of dry-season survival in the two main species of the malarial mosquito Anopheles gambiae.

    PubMed

    Hidalgo, K; Mouline, K; Mamai, W; Foucreau, N; Dabiré, K R; Bouchereau, A; Simard, F; Renault, D

    2015-12-01

    In dry savannahs of West-Africa, the malarial mosquitoes of the Anopheles gambiae sensu stricto complex annually survive the harsh desiccating conditions of the dry season. However, the physiological and biochemical mechanisms underlying how these mosquitoes survive such desiccating conditions are still undefined, and controversial. In this context, we provide the first work examining both proteomic and metabolomic changes in the two molecular forms of A. gambiae s.s (M and S forms) experimentally exposed to the rainy and dry season conditions as they experience in the field. Protein abundances of the mosquitoes were measured using a two-dimensional fluorescence difference gel electrophoresis (2D DIGE) coupled with a matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) and tandem mass spectrometry (MS) for protein identification. These assays were conducted by Applied Biomics (http://www.appliedbiomics.com, Applied Biomics, Inc. Hayward, CA, USA), and the mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository with the dataset identifier PXD000294. The metabolomic analysis was conducted using both Acquity UPLC(®) system (for amino acid identification), and a gas-chromatography-mass spectrometry platform (for sugars identification). Metabolomic fingerprintings were assessed in the University of Rennes 1, UMR CNRS 6553 EcoBio (France). A detailed interpretation of the obtained data can be found in Hidalgo et al. (2014) [1] (Journal of Insect Physiology (2014)). PMID:26543889

  12. Authentication scheme for routine verification of genetically similar laboratory colonies: a trial with Anopheles gambiae

    PubMed Central

    Wilkins, Elien E; Marcet, Paula L; Sutcliffe, Alice C; Howell, Paul I

    2009-01-01

    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. PMID:19849838

  13. Swarming and mating activity of Anopheles gambiae mosquitoes in semi-field enclosures.

    PubMed

    Achinko, D; Thailayil, J; Paton, D; Mireji, P O; Talesa, V; Masiga, D; Catteruccia, F

    2016-03-01

    Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) is the major Afro-tropical vector of malaria. Novel strategies proposed for the elimination and eradication of this mosquito vector are based on the use of genetic approaches, such as the sterile insect technique (SIT). These approaches rely on the ability of released males to mate with wild females, and depend on the application of effective protocols to assess the swarming and mating behaviours of laboratory-reared insects prior to their release. The present study evaluated whether large semi-field enclosures can be utilized to study the ability of males from a laboratory colony to respond to natural environmental stimuli and initiate normal mating behaviour. Laboratory-reared males exhibited spatiotemporally consistent swarming behaviour within the study enclosures. Swarm initiation, peak and termination time closely tracked sunset. Comparable insemination rates were observed in females captured in copula in the semi-field cages relative to females in small laboratory cages. Oviposition rates after blood feeding were also similar to those observed in laboratory settings. The data suggest that outdoor enclosures are suitable for studying swarming and mating in laboratory-bred males in field-like settings, providing an important reference for future studies aimed at assessing the comparative mating ability of strains for SIT and other vector control strategies. PMID:26508420

  14. Whole genome sequence of an unusual Borrelia burgdorferi sensu lato isolate

    SciTech Connect

    Casjens, S.R.; Dunn, J.; Fraser-Liggett, C. M.; Mongodin, E. F.; Qiu, W. G.; Luft, B. J.; Schutzer, S. E.

    2011-03-01

    Human Lyme disease is caused by a number of related Borrelia burgdorferi sensu lato species. We report here the complete genome sequence of Borrelia sp. isolate SV1 from Finland. This isolate is to date the closest known relative of B. burgdorferi sensu stricto, but it is sufficiently genetically distinct from that species that it and its close relatives warrant its candidacy for new-species status. We suggest that this isolate should be named 'Borrelia finlandensis.'

  15. Borrelia burgdorferi sensu lato in humans in a rural area of Paraná State, Brazil

    PubMed Central

    Gonçalves, Daniela Dib; Moura, Rodrigo Assunção; Nunes, Mônica; Carreira, Teresa; Vidotto, Odilon; Freitas, Julio Cesar; Vieira, Maria Luísa

    2015-01-01

    This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s.) in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil. PMID:26273276

  16. Borrelia burgdorferi sensu lato in humans in a rural area of Paraná State, Brazil.

    PubMed

    Gonçalves, Daniela Dib; Moura, Rodrigo Assunção; Nunes, Mônica; Carreira, Teresa; Vidotto, Odilon; Freitas, Julio Cesar; Vieira, Maria Luísa

    2015-06-01

    This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s.) in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil. PMID:26273276

  17. Exploring the origin and degree of genetic isolation of Anopheles gambiae from the islands of São Tomé and Príncipe, potential sites for testing transgenic-based vector control

    PubMed Central

    Marshall, Jonathon C; Pinto, João; Charlwood, Jacques Derek; Gentile, Gabriele; Santolamazza, Federica; Simard, Frèdèric; Della Torre, Alessandra; Donnelly, Martin J; Caccone, Adalgisa

    2008-01-01

    The evolutionary processes at play between island and mainland populations of the malaria mosquito vector Anopheles gambiae sensu stricto are of great interest as islands may be suitable sites for preliminary application of transgenic-based vector control strategies. São Tomé and Príncipe, located off the West African coast, have received such attention in recent years. This study investigates the degree of isolation of An. gambiae s.s. populations between these islands and the mainland based on mitochondrial and ribosomal DNA molecular data. We identify possible continental localities from which these island populations derived. For these purposes, we used FST values, haplotype networks, and nested clade analysis to estimate migration rates and patterns. Haplotypes from both markers are geographically widespread across the African continent. Results indicate that the populations from São Tomé and Príncipe are relatively isolated from continental African populations, suggesting they are promising sites for test releases of transgenic individuals. These island populations are possibly derived from two separate continental migrations. This result is discussed in the context of the history of the African slave trade with respect to São Tomé and Príncipe. PMID:25567803

  18. Repellency of live potted plants against Anopheles gambiae from human baits in semi-field experimental huts.

    PubMed

    Seyoum, Aklilu; Kabiru, Ephantus W; Lwande, Wilber; Killeen, Gerry F; Hassanali, Ahmed; Knols, Bart G J

    2002-08-01

    The repellency of potted plants against the malaria vector Anopheles gambiae sensu stricto Giles was quantified in experimental huts under semi-field conditions inside a screen-walled greenhouse. Ocimum americanum Linnaeus (Labiatae), Lantana camara L. (Verbenaceae), and Lippia uckambensis Spreng (Verbenaceae) repelled at an average of 39.7% (95% confidence interval [CI] = 29.6-48.4%), 32.4% (95% CI = 19.7-43.1%), and 33.3% (95% CI = 21.5-43.3%) of the mosquitoes, respectively (P < 0.0001 for all treatments). This was determined by logistic regression, allowing for variations associated with different bait hosts, sampling huts, and replicate test nights. In contrast, Ocimum kilimandscharicum Guerke (Labiatae), Ocimum suave Willd. (Labiatae), Corymbia citriodora Hook (Myrtaceae), Azadirachta indica A. Juss (Meliaceae), Tagetes minuta L. (Asteraceae), and Hyptis suaveolens Poit. (Lamiaceae) did not significantly repel mosquitoes. The combination of O. americanum with either L. camara or L. uckambensis repelled 31.6% (95% CI = 19.7-41.7%) and 45.2% (95% CI = 34.7-54.0%) of the mosquitoes, respectively (P < 0.0001 for both treatments). This study is the first to show that live intact plants can reduce domestic exposure to malaria vector mosquitoes. As such, they may represent a new, sustainable and readily applicable malaria vector control tool for incorporation into integrated vector management programs. PMID:12389946

  19. Physiology and development of the M and S molecular forms of Anopheles gambiae in Burkina Faso (West Africa).

    PubMed

    Mouline, K; Mamai, W; Agnew, P; Tchonfienet, M; Brengues, C; Dabire, R; Robert, V; Simard, F

    2012-12-01

    In West Africa, M and S molecular forms of Anopheles gambiae sensu stricto (Diptera: Culicidae) Giles, frequently occur together, although with different population bionomics. The S form typically breeds in rain-dependant water collections and is present during the rainy season only whereas the M form can thrive all year long in areas with permanent breeding opportunities. In the present study, we explored physiological and developmental trade-offs at play in laboratory colonies and field populations of the M and S forms that originated from an area of sympatry in Burkina Faso, where M and S larvae exhibit such habitat segregation. In the laboratory, larvae of the M form developed slower than the S form (mean values 9.51 and 8.85 days, respectively, Wilcoxon's test, P < 0.001). Although wing length and dry weight at emergence showed large variations, M females were on average 8% heavier than S females of similar wing length. Higher nutritional reserves (proteins and lipids) in teneral adults explained part of this weight difference, reflecting a better ability of the M form to garner resources at the larval stage. Furthermore, a higher rate of ovarian maturation was observed in the M form after a single bloodmeal. The relevance of these findings for parasite transmission is discussed. PMID:22681446

  20. Sugar-fermenting yeast as an organic source of carbon dioxide to attract the malaria mosquito Anopheles gambiae

    PubMed Central

    2010-01-01

    Background Carbon dioxide (CO2) plays an important role in the host-seeking process of opportunistic, zoophilic and anthropophilic mosquito species and is, therefore, commonly added to mosquito sampling tools. The African malaria vector Anopheles gambiae sensu stricto is attracted to human volatiles augmented by CO2. This study investigated whether CO2, usually supplied from gas cylinders acquired from commercial industry, could be replaced by CO2 derived from fermenting yeast (yeast-produced CO2). Methods Trapping experiments were conducted in the laboratory, semi-field and field, with An. gambiae s.s. as the target species. MM-X traps were baited with volatiles produced by mixtures of yeast, sugar and water, prepared in 1.5, 5 or 25 L bottles. Catches were compared with traps baited with industrial CO2. The additional effect of human odours was also examined. In the laboratory and semi-field facility dual-choice experiments were conducted. The effect of traps baited with yeast-produced CO2 on the number of mosquitoes entering an African house was studied in the MalariaSphere. Carbon dioxide baited traps, placed outside human dwellings, were also tested in an African village setting. The laboratory and semi-field data were analysed by a χ2-test, the field data by GLM. In addition, CO2 concentrations produced by yeast-sugar solutions were measured over time. Results Traps baited with yeast-produced CO2 caught significantly more mosquitoes than unbaited traps (up to 34 h post mixing the ingredients) and also significantly more than traps baited with industrial CO2, both in the laboratory and semi-field. Adding yeast-produced CO2 to traps baited with human odour significantly increased trap catches. In the MalariaSphere, outdoor traps baited with yeast-produced or industrial CO2 + human odour reduced house entry of mosquitoes with a human host sleeping under a bed net indoors. Anopheles gambiae s.s. was not caught during the field trials. However, traps baited with

  1. Landscape Movements of Anopheles gambiae Malaria Vector Mosquitoes in Rural Gambia

    PubMed Central

    Thomas, Christopher J.; Cross, Dónall E.; Bøgh, Claus

    2013-01-01

    Background For malaria control in Africa it is crucial to characterise the dispersal of its most efficient vector, Anopheles gambiae, in order to target interventions and assess their impact spatially. Our study is, we believe, the first to present a statistical model of dispersal probability against distance from breeding habitat to human settlements for this important disease vector. Methods/Principal Findings We undertook post-hoc analyses of mosquito catches made in The Gambia to derive statistical dispersal functions for An. gambiae sensu lato collected in 48 villages at varying distances to alluvial larval habitat along the River Gambia. The proportion dispersing declined exponentially with distance, and we estimated that 90% of movements were within 1.7 km. Although a ‘heavy-tailed’ distribution is considered biologically more plausible due to active dispersal by mosquitoes seeking blood meals, there was no statistical basis for choosing it over a negative exponential distribution. Using a simple random walk model with daily survival and movements previously recorded in Burkina Faso, we were able to reproduce the dispersal probabilities observed in The Gambia. Conclusions/Significance Our results provide an important quantification of the probability of An. gambiae s.l. dispersal in a rural African setting typical of many parts of the continent. However, dispersal will be landscape specific and in order to generalise to other spatial configurations of habitat and hosts it will be necessary to produce tractable models of mosquito movements for operational use. We show that simple random walk models have potential. Consequently, there is a pressing need for new empirical studies of An. gambiae survival and movements in different settings to drive this development. PMID:23874719

  2. Development of a molecular assay to detect predation on Anopheles gambiae complex larval stages.

    PubMed

    Schielke, Erika; Costantini, Carlo; Carchini, Gianmaria; Sagnon, N'falé; Powell, Jeffrey; Caccone, Adalgisa

    2007-09-01

    We developed a molecular assay to detect predation on Anopheles gambiae sensu lato (s.l.) mosquitoes. This intergenic spacer ribosomal DNA polymerase chain reaction assay and restriction enzyme analysis uses An. gambiae-specific primers to detect mosquito DNA in the DNA extracts from whole invertebrate predators, which enables identification of species (An. gambiae s.s. versus An. arabiensis) and molecular forms (M versus S in An. gambiae s.s.). We show that An. gambiae s.l. DNA can be detected after ingestion by members of the families Lestidae (order Odonata) after four hours, Libellulidae (order Odonata) after six hours, and Notonectidae (order Hemiptera) after 24 hours. This method is an improvement over previously published methods because of ease of execution and increased time of detection after ingestion. PMID:17827361

  3. The Gambia.

    PubMed

    1992-12-01

    The Gambia is a country of 11,300 sq. km. with 855,000 inhabitants. Independence was gained on February 18, 1965. The terrain consists of plains and low hills, with a climate which is tropical, yet cooler and dry from November to May. English, Mandinka, Wolof, Fula, and other indigenous languages are spoken by more than 5 ethnic groups who variously are of Muslim, Christian, and animist faith. Life expectancy is 47-51 years. GDP is 331 billion, growing at a rate of 2%. Per capita income is 37 3. The country's natural resources potentially include oil. Peanuts, rice, millet, sorghum, fish, palm kernels, vegetables, livestock, forestry, construction, brewing, soft drinks, machinery assembly, wood and metal working, and clothing are areas of economic production. Textiles, foodstuffs, machinery, and transportation equipment are imported, and re-exported goods, peanuts, palm kernels, fish, and other domestic products are exported. In-depth information is also given on the people and history, government and principal officials, political conditions, the economy, defense, foreign relations, relations with the U.S., and names of principal U.S. officials in the country. PMID:12178054

  4. Fourier transform infrared spectroscopy of DNA from Borrelia burgdorferi sensu lato and Ixodes ricinus ticks.

    PubMed

    Muntean, Cristina M; Stefan, Razvan; Bindea, Maria; Cozma, Vasile

    2013-06-01

    In this work we present a method for detection of motile and immotile Borrelia burgdorferi genomic DNA, in relation with infectious and noninfectious spirochetes. An FT-IR study of DNA isolated from B. burgdorferi sensu lato strains and from positive and negative Ixodes ricinus ticks, respectively, is reported. Motile bacterial cells from the species B. burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii were of interest. Also, FT-IR absorbance spectra of DNA from immotile spirochetes of B. burgdorferi sensu stricto, in the absence and presence of different antibiotics (doxycycline, erythromycin, gentamicin, penicillin V or phenoxymethylpenicillin, tetracycline, respectively) were investigated. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 400-1800 cm(-1). FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Spectral differences between FT-IR absorbances of DNAs from motile bacterial cells and immotile spirochetes, respectively, have been found. Particularly, alterations of the sugar-phosphate B-form chain in the case of DNA from Borrelia immotile cells, as compared with DNA from B. burgdorferi sensu lato motile cells have been observed. Based on this work, specific B. burgdorferi sensu lato and I. ricinus DNA-ligand interactions, respectively, might be further investigated using Fourier transform infrared spectroscopy. PMID:23563637

  5. Molecular and Pathogenic Characterization of Borrelia burgdorferi Sensu Lato Isolates from Spain

    PubMed Central

    Escudero, Raquel; Barral, Marta; Pérez, Azucena; Vitutia, M. Mar; García-Pérez, Ana L.; Jiménez, Santos; Sellek, Ricela E.; Anda, Pedro

    2000-01-01

    Fifteen Borrelia burgdorferi sensu lato isolates from questing ticks and skin biopsy specimens from erythema migrans patients in three different areas of Spain were characterized. Four different genospecies were found (nine Borrelia garinii, including the two human isolates, three B. burgdorferi sensu stricto, two B. valaisiana, and one B. lusitaniae), showing a diverse spectrum of B. burgdorferi sensu lato species. B. garinii isolates were highly variable in terms of pulsed-field gel electrophoresis pattern and OspA serotype, with four of the seven serotypes described. One of the human isolates was OspA serotype 5, the same found in four of seven tick isolates. The second human isolate was OspA serotype 3, which was not present in ticks from the same area. Seven B. garinii isolates were able to disseminate through the skin of C3H/HeN mice and to cause severe inflammation of joints. One of the two B. valaisiana isolates also caused disease in mice. Only one B. burgdorferi sensu stricto isolate was recovered from the urinary bladder. One isolate each of B. valaisiana and B. lusitaniae were not able to disseminate through the skin of mice or to infect internal organs. In summary, there is substantial diversity in the species and in the pathogenicity of B. burgdorferi sensu lato in areas in northern Spain where Lyme disease is endemic. PMID:11060064

  6. Fourier transform infrared spectroscopy of DNA from Borrelia burgdorferi sensu lato and Ixodes ricinus ticks

    NASA Astrophysics Data System (ADS)

    Muntean, Cristina M.; Stefan, Razvan; Bindea, Maria; Cozma, Vasile

    2013-06-01

    In this work we present a method for detection of motile and immotile Borrelia burgdorferi genomic DNA, in relation with infectious and noninfectious spirochetes. An FT-IR study of DNA isolated from B. burgdorferi sensu lato strains and from positive and negative Ixodes ricinus ticks, respectively, is reported. Motile bacterial cells from the species B. burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii were of interest. Also, FT-IR absorbance spectra of DNA from immotile spirochetes of B. burgdorferi sensu stricto, in the absence and presence of different antibiotics (doxycycline, erythromycin, gentamicin, penicillin V or phenoxymethylpenicillin, tetracycline, respectively) were investigated. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 400-1800 cm-1. FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Spectral differences between FT-IR absorbances of DNAs from motile bacterial cells and immotile spirochetes, respectively, have been found. Particularly, alterations of the sugar-phosphate B-form chain in the case of DNA from Borrelia immotile cells, as compared with DNA from B. burgdorferi sensu lato motile cells have been observed. Based on this work, specific B. burgdorferi sensu lato and I. ricinus DNA-ligand interactions, respectively, might be further investigated using Fourier transform infrared spectroscopy.

  7. Differential effects of inbreeding and selection on male reproductive phenotype associated with the colonization and laboratory maintenance of Anopheles gambiae

    PubMed Central

    2014-01-01

    Background Effective mating between laboratory-reared males and wild females is paramount to the success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically modified male mosquitoes. However mosquito colonization and laboratory maintenance have the potential to negatively affect male genotypic and phenotypic quality through inbreeding and selection, which in turn can decrease male mating competitiveness in the field. To date, very little is known about the impact of those evolutionary forces on the reproductive biology of mosquito colonies and how they ultimately affect male reproductive fitness. Methods Here several male reproductive physiological traits likely to be affected by inbreeding and selection following colonization and laboratory rearing were examined. Sperm length, and accessory gland and testes size were compared in male progeny from field-collected females and laboratory strains of Anopheles gambiae sensu stricto colonized from one to over 25 years ago. These traits were also compared in the parental and sequentially derived, genetically modified strains produced using a two-phase genetic transformation system. Finally, genetic crosses were performed between strains in order to distinguish the effects of inbreeding and selection on reproductive traits. Results Sperm length was found to steadily decrease with the age of mosquito colonies but was recovered in refreshed strains and crosses between inbred strains therefore incriminating inbreeding costs. In contrast, testes size progressively increased with colony age, whilst accessory gland size quickly decreased in males from colonies of all ages. The lack of heterosis in response to crossing and strain refreshing in the latter two reproductive traits suggests selection for insectary conditions. Conclusions These results show that inbreeding and selection differentially affect reproductive traits in laboratory strains overtime and that

  8. Pyrethroid resistance in Anopheles gambiae leads to increased susceptibility to the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana

    PubMed Central

    2010-01-01

    Background Entomopathogenic fungi are being investigated as a new mosquito control tool because insecticide resistance is preventing successful mosquito control in many countries, and new methods are required that can target insecticide-resistant malaria vectors. Although laboratory studies have previously examined the effects of entomopathogenic fungi against adult mosquitoes, most application methods used cannot be readily deployed in the field. Because the fungi are biological organisms it is important to test potential field application methods that will not adversely affect them. The two objectives of this study were to investigate any differences in fungal susceptibility between an insecticide-resistant and insecticide-susceptible strain of Anopheles gambiae sensu stricto, and to test a potential field application method with respect to the viability and virulence of two fungal species Methods Pieces of white polyester netting were dipped in Metarhizium anisopliae ICIPE-30 or Beauveria bassiana IMI391510 mineral oil suspensions. These were kept at 27 ± 1°C, 80 ± 10% RH and the viability of the fungal conidia was recorded at different time points. Tube bioassays were used to infect insecticide-resistant (VKPER) and insecticide-susceptible (SKK) strains of An. gambiae s.s., and survival analysis was used to determine effects of mosquito strain, fungus species or time since fungal treatment of the net. Results The resistant VKPER strain was significantly more susceptible to fungal infection than the insecticide-susceptible SKK strain. Furthermore, B. bassiana was significantly more virulent than M. anisopliae for both mosquito strains, although this may be linked to the different viabilities of these fungal species. The viability of both fungal species decreased significantly one day after application onto polyester netting when compared to the viability of conidia remaining in suspension. Conclusions The insecticide-resistant mosquito strain was susceptible

  9. Camarosporium arezzoensis on Cytisus sp., an addition to sexual state of Camarosporium sensu stricto

    PubMed Central

    Tibpromma, Saowaluck; Wijayawardene, Nalin N.; Manamgoda, Dimuthu S.; Boonmee, Saranyaphat; Wanasinghe, Dhanushka N.; Camporesi, Erio; Yang, Jun-Bo; Hyde, Kevin D.

    2015-01-01

    During a study of saprobic fungi from Bagno di Cetica Province, Italy, we collected a pleosporoid ascomycete on stems of Cytisus sp. In morphology, our collection is similar to Cucurbitaria species, but molecular analysis of SSU, LSU and ITS genes reveals it can be referred to Camarosporium. In this study we compare all other Cucurbitaria species from Cytisus sp. and based on both morphology and molecular data, we introduce our collection as a new species in Camarosporium viz. C. arezzoensis. PMID:26858532

  10. Genome Sequencing and Comparative Analysis of the Biocontrol Agent Trichoderma harzianum sensu stricto TR274

    SciTech Connect

    Steindorff, Andrei S.; Noronha, Elilane F.; Ulhoa, Cirano J.; Kuo, Alan; Salamov, Asaf A.; Haridas, Sajeet; Riley, Robert W.; Druzhinina, Irina S.; Kubicek, Christian P.; Grigoriev, Igor V.

    2015-03-17

    Biological control is a complex process which requires many mechanisms and a high diversity of biochemical pathways. The species of Trichoderma harzianum are well known for their biocontrol activity against many plant pathogens. To gain new insights into the biocontrol mechanism used by T. harzianum, we sequenced the isolate TR274 genome using Illumina. The assembly was performed using AllPaths-LG with a maximum coverage of 100x. The assembly resulted in 2282 contigs with a N50 of 37033bp. The genome size generated was 40.8 Mb and the GC content was 47.7%, similar to other Trichoderma genomes. Using the JGI Annotation Pipeline we predicted 13,932 genes with a high transcriptome support. CEGMA tests suggested 100% genome completeness and 97.9% of RNA-SEQ reads were mapped to the genome. The phylogenetic comparison using orthologous proteins with all Trichoderma genomes sequenced at JGI, corroborates the Trichoderma (T. asperellum and T. atroviride), Longibrachiatum (T. reesei and T. longibrachiatum) and Pachibasium (T. harzianum and T. virens) section division described previously. The comparison between two Trichoderma harzianum species suggests a high genome similarity but some strain-specific expansions. Analyses of the secondary metabolites, CAZymes, transporters, proteases, transcription factors were performed. The Pachybasium section expanded virtually all categories analyzed compared with the other sections, specially Longibrachiatum section, that shows a clear contraction. These results suggests that these proteins families have an important role in their respective phenotypes. Future analysis will improve the understanding of this complex genus and give some insights about its lifestyle and the interactions with the environment.

  11. Seed dispersal and predation of Buchenavia tomentosa Eichler (Combretaceae) in a Cerrado sensu stricto, midwest Brazil.

    PubMed

    Farias, J; Sanchez, M; Abreu, M F; Pedroni, F

    2015-11-01

    The ecology of seed dispersal is critical to understand the patterns of distribution and abundance of plant species. We investigated seed dispersal aspects associated with the high abundance of Buchenavia tomentosa in the Serra Azul State Park (PESA). We estimated fruit production and conducted fruit removal experiments. We carried out diurnal and nocturnal observations on frugivory as well as germination tests. Fruiting occurred in the dry season and totaled 1,365,015 ± 762,670 fruits.ha-1. B. tomentosa fruits were utilized by eight animal species. The lowland tapir (Tapirus terrestris) was considered the main seed disperser. Leafcutter ants (Atta laevigata and Atta sexdens) participated in the seed cleaning and occasionally dispersed seeds. The beetle Amblycerus insuturatus, blue-and-yellow macaw (Ara ararauna) and red-and-green macaw (Ara chloropterus) were considered pre-dispersal seed predators. The seeds manually cleaned presented higher germination rate (100%) and speed index (4.2 seeds.d-1) than that of seeds with pulp. Germination of seeds found in tapirs'feces was 40%, while for the seeds without pulp it was 25%. The high abundance of B. tomentosa in the cerrado of PESA may be due to massive fruit production, low rates of seed predation, and efficient seed dispersal by tapirs, occurring before the rains which promote germination and recruitment of this species. PMID:26602355

  12. Nucleotide polymorphisms and protein structure changes in the Fg16 gene of Fusarium graminearum sensu stricto.

    PubMed

    Abedi-Tizaki, Mostafa; Zafari, Doustmorad

    2016-09-01

    Fusarium graminearum is one of the most important causes of wheat scab in different parts of the world. This fungus is able to produce widespread trichothecene mycotoxins such as nivalenol (NIV) and deoxynivalenol (DON) which are harmful for both human and animals. The Fg16 target is located in chromosome 1 of the F. graminearum genome coding for a hypothetical protein whose function is not yet known. The Fg16 gene is involved in lipid biosynthesis and leads to sexual development during colonization in wheat stalks. This gene is used to detect F. graminearum and determine the lineage of F. graminearum complex species. In the present study, polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and DNA sequencing methods were employed in screening for genetic variation in 172 F. graminearum s.s. isolates. The PCR reaction forced the amplification of 410-bp fragments of Fg16. Two single nucleotide polymorphisms (T82C and A352T) and one amino acid exchange (C65S) with three patterns (TA/TA, CT/CT and TA/CT genotypes) were found in the Fg16 gene fragment. Two haplotypes, 1A and 1B, were identified within F. graminearum s.s. populations in northern and western regions of Iran. Two different secondary structures of protein were predicted for CT/CT and TA/CT genotypes of Fg16 gene. The average diversity levels detected were relatively high (He: 0.3238; Heu: 0.334; Ho: 0.2894; mean PIC: 0.514; mean Shannon's information index: 0.4132; mean number of alleles per locus: 1.473). On the basis of the obtained results, it was revealed that the Fg16 gene had a high degree of polymorphism that can be considered for future control programming strategies and thus the associations between the SSCP patterns with different traits of F. graminearum such as wheat colonization, perithecium formation on stalk tissues and lineage discrimination should be investigated. PMID:27222818

  13. Cases of Echinococcus granulosus Sensu Stricto Isolated from Polish Patients: Imported or Indigenous?

    PubMed Central

    Dybicz, Monika; Borkowski, Piotr Karol; Dąbrowska, Julia; Chomicz, Lidia

    2015-01-01

    The cases of nine Polish patients with diagnosed cystic echinococcosis (CE) were examined. A total of nine isolates obtained postoperatively were investigated using PCR and sequencing. The mitochondrial region of nad1 gene was amplified. This PCR and sequencing analysis revealed the presence of Echinococcus canadensis G7 in seven patients and E. granulosus G1 in two patients. These data demonstrate that E. canadensis is the predominant causative agent of human cystic echinococcosis in Poland. E. granulosus G1 detection in Polish patients suggests that the parasite was imported; however it does not exclude the possibility that these cases could have been of Polish origin. PMID:26491683

  14. Camarosporium arezzoensis on Cytisus sp., an addition to sexual state of Camarosporium sensu stricto.

    PubMed

    Tibpromma, Saowaluck; Wijayawardene, Nalin N; Manamgoda, Dimuthu S; Boonmee, Saranyaphat; Wanasinghe, Dhanushka N; Camporesi, Erio; Yang, Jun-Bo; Hyde, Kevin D

    2016-01-01

    During a study of saprobic fungi from Bagno di Cetica Province, Italy, we collected a pleosporoid ascomycete on stems of Cytisus sp. In morphology, our collection is similar to Cucurbitaria species, but molecular analysis of SSU, LSU and ITS genes reveals it can be referred to Camarosporium. In this study we compare all other Cucurbitaria species from Cytisus sp. and based on both morphology and molecular data, we introduce our collection as a new species in Camarosporium viz. C. arezzoensis. PMID:26858532

  15. Nucleotide polymorphisms and protein structure changes in the Fg16 gene of Fusarium graminearum sensu stricto

    PubMed Central

    Abedi-Tizaki, Mostafa; Zafari, Doustmorad

    2016-01-01

    Fusarium graminearum is one of the most important causes of wheat scab in different parts of the world. This fungus is able to produce widespread trichothecene mycotoxins such as nivalenol (NIV) and deoxynivalenol (DON) which are harmful for both human and animals. The Fg16 target is located in chromosome 1 of the F. graminearum genome coding for a hypothetical protein whose function is not yet known. The Fg16 gene is involved in lipid biosynthesis and leads to sexual development during colonization in wheat stalks. This gene is used to detect F. graminearum and determine the lineage of F. graminearum complex species. In the present study, polymerase chain reaction–single strand conformational polymorphism (PCR–SSCP) and DNA sequencing methods were employed in screening for genetic variation in 172 F.graminearum s.s. isolates. The PCR reaction forced the amplification of 410-bp fragments of Fg16. Two single nucleotide polymorphisms (T82C and A352T) and one amino acid exchange (C65S) with three patterns (TA/TA, CT/CT and TA/CT genotypes) were found in the Fg16 gene fragment. Two haplotypes, 1A and 1B, were identified within F. graminearum s.s. populations in northern and western regions of Iran. Two different secondary structures of protein were predicted for CT/CT and TA/CT genotypes of Fg16 gene. The average diversity levels detected were relatively high (He: 0.3238; Heu: 0.334; Ho: 0.2894; mean PIC: 0.514; mean Shannon's information index: 0.4132; mean number of alleles per locus: 1.473). On the basis of the obtained results, it was revealed that the Fg16 gene had a high degree of polymorphism that can be considered for future control programming strategies and thus the associations between the SSCP patterns with different traits of F. graminearum such as wheat colonization, perithecium formation on stalk tissues and lineage discrimination should be investigated. PMID:27222818

  16. Tenuipalpus sensu stricto (Acari: Tenuipalpidae) from Brazil, with ontogeny and a key to the known species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Cerrado is the second largest Brazilian biome, and is considered to be a “hotspot” due the great concentration of en-demic species and high rate of deforestation. Surveys of the mite fauna present in this biome have revealed a great number of new species. In this paper, we describe Tenuipalpus s...

  17. First report of Borrelia burgdorferi sensu lato in two threatened carnivores: the Marbled polecat, Vormela peregusna and the European mink, Mustela lutreola (Mammalia: Mustelidae)

    PubMed Central

    2012-01-01

    Background Lyme disease is a widespread cosmopolitan zoonosis caused by species belonging to the genus Borrelia. It is transmitted from animal reservoir hosts to humans through hard - ticks of genus Ixodes which are vectors of the disease. Case presentation Borrelia burgdorferi sensu lato infection was identified in a marbled polecat, Vormela peregusna, and two European minks, Mustela lutreola, from Romania, by PCR. RFLP revealed the presence of a single genospecies, Borrelia burgdorferi sensu stricto. Conclusions This is the first report of the Lyme disease spirochetes in the two mentioned hosts. PMID:22901862

  18. Analyses of mammalian sera in enzyme-linked immunosorbent assays with different strains of Borrelia burgdorferi sensu lato.

    PubMed

    Magnarelli, L A; Anderson, J F; Johnson, R C

    1995-04-01

    Blood samples were collected from cottontail rabbits (Sylvilagus floridanus), raccoons (Procyon lotor), white-footed mice (Peromyscus leucopus), and white-tailed deer (Odocoileus virginianus) between 1977 and 1991 in southern Connecticut and New York State (USA) and were tested for antibodies against eight strains of Borrelia burgdorferi sensu lato in enzyme-linked immunosorbent assays. Among these spirochetes were six strains of B. burgdorferi sensu stricto, one strain of B. garinii (=IP90) and a strain (IPF) in group VS461. Sera from each study group reacted positively to all strains having origins in North America and Eurasia. Assay sensitivities normally ranged between 85% and 100% for all study groups. The lowest sensitivity (66%) was noted when mouse sera were tested with B. garinii, an isolate from Ixodes persulcatus in the former Soviet Union. Differences in serum reactivity to various strains were noted for all study groups, but because of multiple shared antigens among the closely related spirochetes tested, the selection of a particular North American strain of B. burgdorferi sensu stricto did not appear to be a critical factor for optimal assay performance. Locally obtained strains of this bacterium are preferred as coating antigens for serologic testing because of their availability. PMID:8583632

  19. Laboratory and field evaluation of the impact of washings on the effectiveness of LifeNet®, Olyset® and PermaNet® 2.0 in two areas, where there is a high level of resistance of Anopheles gambiae to pyrethroids, Benin, West Africa

    PubMed Central

    2014-01-01

    Background An investigation carried out in Benin has shown that, in some areas close to rivers where density of mosquitoes is high, long-lasting, insecticidal bed nets (LLINs) are permanently used. In such areas, LLINs are washed every month. Based on this situation, the 20-wash minimum efficacy advised by the manufacturers would be inadequate. The main goal of this study was to evaluate the effectiveness of LifeNet®, Olyset® and Permanet® 2.0 washed several times against Anopheles gambiae sensu stricto (s.s.) populations, which have developed high resistance to pyrethroids. Methods Efficacy of LifeNet®, Olyset® and PermaNet® 2.0 washed 30 and 40 times was expressed in terms of blood-feeding inhibition rate, deterrence, induced exophily and mortality rates. This WHOPES phase II evaluation, conducted in experimental huts in Akron (southern Benin) and in Malanville (northern Benin), was accompanied by WHOPES Phase I evaluation. Results Over 40 successive washes, LifeNet® induced a mortality rate over 80% in phase I. However, beyond 10 washes, Permanet® 2.0 and Olyset induced dramatically reduced mortality rates, respectively 12.5 and 2.5%. With regard to Phase II results, unwashed LifeNet®, LifeNet® and Olyset® washed 30 and 40 times induced a similar exophily rate per study site (at least 58% in Malanville and at least 71% in Akron). Regarding blood feeding inhibition, LifeNet® and Olyset® washed 30 and 40 times significantly reduced wild An. gambiae s.s. blood feeding showing a similar personal protection as unwashed LifeNet®. LifeNet® washed 30 and 40 times induced mortality rates significantly higher than those induced by Olyset® and Permanet® 2.0 (P < 0,05). Conclusion LifeNet®, followed by Olyset®, have shown good efficacy against host-seeking resistant An. gambiae s.s. population in experimental huts in Benin. Lifenet® have shown to be an effective and promising vector control tool to prevent malaria in areas where repeated washings is

  20. The EmsB Tandemly Repeated Multilocus Microsatellite: a New Tool To Investigate Genetic Diversity of Echinococcus granulosus Sensu Lato▿

    PubMed Central

    Maillard, S.; Gottstein, B.; Haag, K. L.; Ma, S.; Colovic, I.; Benchikh-Elfegoun, M. C.; Knapp, J.; Piarroux, R.

    2009-01-01

    Cystic echinococcosis (CE) is a widespread and severe zoonotic disease caused by infection with the larval stage of the eucestode Echinococcus granulosus sensu lato. The polymorphism exhibited by nuclear and mitochondrial markers conventionally used for the genotyping of different parasite species and strains does not reach the level necessary for the identification of genetic variants linked to restricted geographical areas. EmsB is a tandemly repeated multilocus microsatellite that proved its usefulness for the study of genetic polymorphisms within the species E. multilocularis, the causative agent of alveolar echinococcosis. In the present study, EmsB was used to characterize E. granulosus sensu lato samples collected from different host species (sheep, cattle, dromedaries, dogs, and human patients) originating from six different countries (Algeria, Mauritania, Romania, Serbia, Brazil, and the People's Republic of China). The conventional mitochondrial cox1 and nad1 markers identified genotypes G1, G3, G5, G6, and G7, which are clustered into three groups corresponding to the species E. granulosus sensu stricto, E. ortleppi, and E. canadensis. With the same samples, EmsB provided a higher degree of genetic discrimination and identified variations that correlated with the relatively small-scale geographic origins of the samples. In addition, one of the Brazilian single hydatid cysts presented a hybrid genotypic profile that suggested genetic exchanges between E. granulosus sensu stricto and E. ortleppi. In summary, the EmsB microsatellite exhibits an interesting potential for the elaboration of a detailed map of the distribution of genetic variants and therefore for the determination and tracking of the source of CE. PMID:19741078

  1. The EmsB tandemly repeated multilocus microsatellite: a new tool to investigate genetic diversity of Echinococcus granulosus sensu lato.

    PubMed

    Maillard, S; Gottstein, B; Haag, K L; Ma, S; Colovic, I; Benchikh-Elfegoun, M C; Knapp, J; Piarroux, R

    2009-11-01

    Cystic echinococcosis (CE) is a widespread and severe zoonotic disease caused by infection with the larval stage of the eucestode Echinococcus granulosus sensu lato. The polymorphism exhibited by nuclear and mitochondrial markers conventionally used for the genotyping of different parasite species and strains does not reach the level necessary for the identification of genetic variants linked to restricted geographical areas. EmsB is a tandemly repeated multilocus microsatellite that proved its usefulness for the study of genetic polymorphisms within the species E. multilocularis, the causative agent of alveolar echinococcosis. In the present study, EmsB was used to characterize E. granulosus sensu lato samples collected from different host species (sheep, cattle, dromedaries, dogs, and human patients) originating from six different countries (Algeria, Mauritania, Romania, Serbia, Brazil, and the People's Republic of China). The conventional mitochondrial cox1 and nad1 markers identified genotypes G1, G3, G5, G6, and G7, which are clustered into three groups corresponding to the species E. granulosus sensu stricto, E. ortleppi, and E. canadensis. With the same samples, EmsB provided a higher degree of genetic discrimination and identified variations that correlated with the relatively small-scale geographic origins of the samples. In addition, one of the Brazilian single hydatid cysts presented a hybrid genotypic profile that suggested genetic exchanges between E. granulosus sensu stricto and E. ortleppi. In summary, the EmsB microsatellite exhibits an interesting potential for the elaboration of a detailed map of the distribution of genetic variants and therefore for the determination and tracking of the source of CE. PMID:19741078

  2. Molecular Characterization of Echinococcus granulosus Sensu Lato from Farm Animals in Egypt

    PubMed Central

    Amer, Said; Helal, Ibrahim B.; Kamau, Evelyne; Feng, Yaoyu; Xiao, Lihua

    2015-01-01

    Little is known on the diversity and public health significance of Echinococcus species in livestock in Egypt. In this study, 37 individual hydatid cysts were collected from dromedary camels (n=28), sheep (n=7) and buffalos (n=2). DNA was extracted from protoscoleces/germinal layer of individual cysts and amplified by PCR targeting nuclear (actin II) and mitochondrial (COX1 and NAD1) genes. Direct sequencing of amplicons indicated the presence of Echinococcus canadenesis (G6 genotype) in 26 of 28 camel cysts, 3 of 7 sheep cysts and the 2 buffalo derived cysts. In contrast, Echinococcus granulosus sensu stricto (G1 genotype) was detected in one cyst from a camel and 4 of 7 cysts from sheep, whereas Echinococcus ortleppi (G5 genotype) was detected in one cyst from a camel. This is the first identification of E. ortleppi in Egypt. PMID:25760944

  3. Comparative histology of floral elaiophores in the orchids Rudolfiella picta (Schltr.) Hoehne (Maxillariinae sensu lato) and Oncidium ornithorhynchum H.B.K. (Oncidiinae sensu lato)

    PubMed Central

    Davies, Kevin L.; Stpiczyńska, Malgorzata

    2009-01-01

    Background and Aims Floral elaiophores, although widespread amongst orchids, have not previously been described for Maxillariinae sensu lato. Here, two claims that epithelial, floral elaiophores occur in the genus Rudolfiella Hoehne (Bifrenaria clade) are investigated. Presumed elaiophores were compared with those of Oncidiinae Benth. and the floral, resin-secreting tissues of Rhetinantha M.A. Blanco and Heterotaxis Lindl., both genera formerly assigned to Maxillaria Ruiz & Pav. (Maxillariinae sensu stricto). Methods Putative, floral elaiophore tissue of Rudolfiella picta (Schltr.) Hoehne and floral elaiophores of Oncidium ornithorhynchum H.B.K. were examined by means of light microscopy, histochemistry, scanning electron microscopy and transmission electron microscopy. Key Results and Conclusions Floral, epithelial elaiophores are present in Rudolfiella picta, indicating, for the first time, that oil secretion occurs amongst members of the Bifrenaria clade (Maxillariinae sensu lato). However, whereas the elaiophore of R. picta is borne upon the labellar callus, the elaiophores of O. ornithorhynchum occur on the lateral lobes of the labellum. In both species, the elaiophore comprises a single layer of palisade secretory cells and parenchymatous, subsecretory tissue. Cell wall cavities are absent from both and there is no evidence of cuticular distension in response to oil accumulation between the outer tangential wall and the overlying cuticle in R. picta. Distension of the cuticle, however, occurs in O. ornithorhynchum. Secretory cells of R. picta contain characteristic, spherical or oval plastids with abundant plastoglobuli and these more closely resemble plastids found in labellar, secretory cells of representatives of Rhetinantha (formerly Maxillaria acuminata Lindl. alliance) than elaiophore plastids of Oncidiinae. In Rhetinantha, such plastids are involved in the synthesis of resin-like material or wax. Despite these differences, the elaiophore anatomy of

  4. A phylogenetic re-appraisal of the family Liagoraceae sensu lato (Nemaliales, Rhodophyta) based on sequence analyses of two plastid genes and postfertilization development.

    PubMed

    Lin, Showe-Mei; Rodríguez-Prieto, Conxi; Huisman, John M; Guiry, Michael D; Payri, Claude; Nelson, Wendy A; Liu, Shao-Lun

    2015-06-01

    The marine red algal family Liagoraceae sensu lato is shown to be polyphyletic based on analyses of a combined rbcL and psaA data set and the pattern of carposporophyte development. Fifteen of eighteen genera analyzed formed a monophyletic lineage that included the genus Liagora. Nemalion did not cluster with Liagoraceae sensu stricto, and Nemaliaceae is reinstated, characterized morphologically by the formation of the primary gonimolobes by longitudinal divisions of the gonimoblast initial. Yamadaella and Liagoropsis, previously placed in the Dermonemataceae, are shown to be independent lineages and are recognized as two new families Yamadaellaceae and Liagoropsidaceae. Yamadaellaceae is characterized by two gonimoblast initials cut off bilaterally from the fertilized carpogonium and diffusely spreading gonimoblast filaments. Liagoropsidaceae is characterized by at least three gonimoblast initials cut off by longitudinal septa from the fertilized carpogonium. In contrast, Liagoraceae sensu stricto is characterized by a single gonimoblast initial cut off transversely or diagonally from the fertilized carpogonium. Reproductive features, such as diffuse gonimoblasts and unfused carpogonial branches following postfertilization, appear to have evolved on more than one occasion in the Nemaliales and are therefore not taxonomically diagnostic at the family level, although they may be useful in recognizing genera. PMID:26986669

  5. Taxonomy and molecular epidemiology of Echinococcus granulosus sensu lato.

    PubMed

    Romig, T; Ebi, D; Wassermann, M

    2015-10-30

    Echinococcus granulosus, formerly regarded as a single species with a high genotypic and phenotypic diversity, is now recognised as an assemblage of cryptic species, which differ considerably in morphology, development, host specificity (including infectivity/pathogenicity for humans) and other aspects. This diversity is reflected in the mitochondrial and nuclear genomes and has led to the construction of phylogenetic trees and hypotheses on the origin and geographic dispersal of various taxa. Based on phenotypic characters and gene sequences, E. granulosus (sensu lato) has by now been subdivided into E. granulosus sensu stricto (including the formerly identified genotypic variants G1-3), Echinococcus felidis (the former 'lion strain'), Echinococcus equinus (the 'horse strain', genotype G4), Echinococcus ortleppi (the 'cattle strain', genotype G5) and Echinococcus canadensis. The latter species, as recognised here, shows the highest diversity and is composed of the 'camel strain', genotype G6, the 'pig strain', genotype G7, and two 'cervid strains', genotypes G8 and G10. There is debate whether the closely related G6 and G7 should be placed in a separate species, but more morphological and biological data are needed to support or reject this view. In this classification, the application of rules for zoological nomenclature led to the resurrection of old species names, which had before been synonymised with E. granulosus. This nomenclatural subdivision of the agents of cystic echinococcosis (CE) may appear inconvenient for practical applications, especially because molecular tools are needed for identification of the cyst stage, and because retrospective data on 'E. granulosus' are now difficult to interpret without examination of voucher specimens. However, the increased awareness for the diversity of CE agents - now emphasised by species names rather than genotype numbers - has led to a large number of recent studies on this issue and a rapid increase of knowledge

  6. Occurrence of Anisakis simplex sensu stricto in imported Atlantic mackerel (Scomber scombrus) represents a risk for Turkish consumers.

    PubMed

    Pekmezci, Gokmen Zafer

    2014-08-18

    Anisakid larvae are a prevalent food-borne pathogen that has been found in numerous fish species destined for human consumption. The accidental consumption of infected raw or poorly cooked fish may cause gastroenteric diseases and allergies in humans. In spite of the fact that thorough cooking or freezing kills Anisakis worms, this method does not destroy their allergenic capacity. The presence of A. simplex (s.s.) in seafood products may present a health risk for consumers. In Turkey, Atlantic mackerels are marketed as frozen and mainly imported from Norway. The aim of this study was to identify the Anisakis species found in deep-frozen whole Atlantic mackerel (Scomber scombrus) destined for human consumption in fish markets that imported fish from Norway to Turkey. All Anisakis larvae isolated from imported Atlantic mackerel were identified via morphology as third larvae of Anisakis Type I. The ITS region (ITS-1, 5.8S subunit, ITS-2) was amplified and digested with the restriction enzymes Hinf I and Hha I. Larvae of the genus Anisakis were identified via PCR-RFLP as belonging to Anisakis simplex (s.s.), and this was confirmed by sequencing the cox2 gene. The overall prevalence of Anisakis larvae was 25% (95% confidence limits: 13-41%), and the mean intensity was 19.1 (bootstrap 95% confidence limits: 15.3-25.5). Recognized zoonotic A. simplex (s.s.) larvae found in imported Atlantic mackerel could represent a risk. Those who consume them could acquire parasitic allergies. The results will have an important impact on public health risk assessment in that they suggest reviewing critical control points at the Hazard Analysis Critical Control Point (HACCP) programmer to reduce the risk of anisakid-induced allergies among consumers. Consequently, the present study provides the first data regarding the occurrence of A. simplex (s.s.) larvae in imported Atlantic mackerel in Turkish markets. PMID:24935687

  7. CONTRASTING PATTERNS OF GENETIC DIVERSITY AND POPULATION STRUCTURE OF ARMILLARIA MELLEA SENSU STRICTO IN THE EASTERN AND WESTERN UNITED STATES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Armillaria mellea infects over 300 hosts in natural and managed ecosystems throughout the Northern Hemisphere. Previously reported nuclear genetic divergenece between eastern and western US isolates is consistent with the disjunct range of A. mellea in N. America, which is restricted mainly to the ...

  8. MULTIPLE ENZYME RESTRICTION FRAGMENT LENGTH POLYMORPHISM ANALYSIS FOR HIGH RESOLUTION DISTINCTION OF PSEUDOMONAS (SENSU STRICTO) 16S RRNA GENES

    EPA Science Inventory

    Pseudomonas specific 16S rDNA PCR amplification and multiple enzyme restriction fragment length polymorphism (MERFLP) analysis using a single digestion mixture of Alu I, Hinf I, Rsa I, and Tru 9I distinguished 150 published sequences and reference strains of authentic Pseudomonas...

  9. Comparative Genome Hybridization Reveals Substantial Variation among Clinical Isolates of Borrelia burgdorferi Sensu Stricto with Different Pathogenic Properties

    PubMed Central

    Terekhova, Darya; Iyer, Radha; Wormser, Gary P.; Schwartz, Ira

    2006-01-01

    Clinical and murine studies suggest that there is a differential pathogenicity of different genotypes of Borrelia burgdorferi, the spirochetal agent of Lyme disease. Comparative genome hybridization was used to explore the relationship between different genotypes. The chromosomes of all studied isolates were highly conserved (>93%) with respect to both sequence and gene order. Plasmid sequences were substantially more diverse. Plasmids lp54, cp26, and cp32 were present in all tested isolates, and their sequences and gene order were conserved. The majority of linear plasmids showed variation both in terms of presence among different isolates and in terms of sequence and gene order. The data strongly imply that all B. burgdorferi clinical isolates contain linear plasmids related to each other, but the structure of these replicons may vary substantially from isolate to isolate. These alterations include deletions and presumed rearrangements that are likely to result in unique plasmid elements in many isolates. There is a strong correlation between complete genome hybridization profiles and other typing methods, which, in turn, also correlate to differences in pathogenicity. Because there is substantially less variation in the chromosomal and circular plasmid portions of the genome, the major differences in open reading frame content and genomic diversity among isolates are linear plasmid driven. PMID:16923879

  10. A HIGHLY SELECTIVE PCR PROTOCOL FOR DETECTING 16S RRNA GENES OF THE GENUS PSEUDOMONAS (SENSU STRICTO) IN ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    Pseudomonas species are plant, animal, and human pathogens; exhibit plant pathogen-suppressing properties useful in biological control; or express metabolic versatilities valued in biotechnology and bioremediation. Specific detection of Pseudomonas species in the environment may ...

  11. Genetic diversity, endemism and phylogeny of lampreys within the genus Lampetra sensu stricto (Petromyzontiformes: Petromyzontidae) in western North America.

    PubMed

    Boguski, D A; Reid, S B; Goodman, D H; Docker, M F

    2012-11-01

    Phylogenetic structure of four Lampetra species from the Pacific drainage of North America (western brook lamprey Lampetra richardsoni, Pacific brook lamprey Lampetra pacifica, river lamprey Lampetra ayresii and Kern brook lamprey Lampetra hubbsi) and unidentified Lampetra specimens (referred to as Lampetra sp.) from 36 locations was estimated using the mitochondrial cytochrome b gene. Maximum parsimony and Bayesian inferences did not correspond with any taxonomic scheme proposed to date. Rather, although L. richardsoni (from Alaska to California) and L. ayresii (from British Columbia to California) together constituted a well-supported clade distinct from several genetically divergent Lampetra populations in Oregon and California, these two species were not reciprocally monophyletic. The genetically divergent populations included L. pacifica (from the Columbia River basin) and L. hubbsi (from the Kern River basin) and four Lampetra sp. populations in Oregon (Siuslaw River and Fourmile Creek) and California (Kelsey and Mark West Creeks). These four Lampetra sp. populations showed genetic divergence between 2.3 and 5.7% from any known species (and up to 8.0% from each other), and may represent morphologically cryptic and thus previously undescribed species. A fifth population (from Paynes Creek, California) may represent a range extension of L. hubbsi into the Upper Sacramento River. PMID:23130690

  12. A molecular phylogeny and classification of Leptochloa (Poaceae: Chloridoideae: Chlorideae) sensu lato and related genera

    PubMed Central

    Peterson, Paul M.; Romaschenko, Konstantin; Snow, Neil; Johnson, Gabriel

    2012-01-01

    Background and Aims Leptochloa (including Diplachne) sensu lato (s.l.) comprises a diverse assemblage of C4 (NAD-ME and PCK) grasses with approx. 32 annual or perennial species. Evolutionary relationships and a modern classification of Leptochloa spp. based on the study of molecular characters have only been superficially investigated in four species. The goals of this study were to reconstruct the evolutionary history of Leptochloa s.l. with molecular data and broad taxon sampling. Methods A phylogenetic analysis was conducted of 130 species (mostly Chloridoideae), of which 22 are placed in Leptochloa, using five plastid (rpL32-trn-L, ndhA intron, rps16 intron, rps16-trnK and ccsA) and the nuclear ITS 1 and 2 (ribosomal internal transcribed spacer regions) to infer evolutionary relationships and revise the classification. Key results Leptochloa s.l. is polyphyletic and strong support was found for five lineages. Embedded within the Leptochloa sensu stricto (s.s.) clade are two Trichloris spp. and embedded in Dinebra are Drake-brockmania and 19 Leptochloa spp. Conclusions The molecular results support the dissolution of Leptochloa s.l. into the following five genera: Dinebra with 23 species, Diplachne with two species, Disakisperma with three species, Leptochloa s.s. with five species and a new genus, Trigonochloa, with two species. PMID:22628365

  13. Calosoma aethiops (Jeannel, 1940) as a new synonym of Calosoma imbricatum hottentotum Chaudoir, 1852, a new status of Calosoma roeschkei Breuning, 1927, and a revision of the Calosoma senegalense group sensu Häckel, 2012 (Coleoptera, Carabidae, Carabini)

    PubMed Central

    Häckel, Martin; Farkač, Jan; Sehnal, Rostislav

    2016-01-01

    Abstract Calosoma aethiops (Jeannel, 1940) as a new synonym of Calosoma imbricatum hottentotum Chaudoir, 1852, a new status of Calosoma roeschkei Breuning, 1927, and a revision of the Calosoma senegalense group sensu Häckel, 2012 (Coleoptera: Carabidae: Carabini). Conducted is a taxonomic revision of the Calosoma senegalense group sensu Häckel, 2012. Placed in the group sensu stricto are four species: Calosoma planicolle Chaudoir, 1869, Calosoma scabrosum Chaudoir, 1843, Calosoma senegalense Dejean, 1831, and Ctenosta strandi Breuning, 1934. Calosoma aethiops Jeannel, 1940 is synonymized with Calosoma imbricatum hottentotum Chaudoir, 1852, and Calosoma roeschkei Breuning, 1927 is newly regarded as a subspecies of Calosoma scabrosum. The taxonomic conclusions are based on morphometry of the holotypes and 10 male and 10 female specimens of each taxon, and on morphology of the aedeagus including inflated endophalus. PMID:27563269

  14. Calosoma aethiops (Jeannel, 1940) as a new synonym of Calosoma imbricatum hottentotum Chaudoir, 1852, a new status of Calosoma roeschkei Breuning, 1927, and a revision of the Calosoma senegalense group sensu Häckel, 2012 (Coleoptera, Carabidae, Carabini).

    PubMed

    Häckel, Martin; Farkač, Jan; Sehnal, Rostislav

    2016-01-01

    Calosoma aethiops (Jeannel, 1940) as a new synonym of Calosoma imbricatum hottentotum Chaudoir, 1852, a new status of Calosoma roeschkei Breuning, 1927, and a revision of the Calosoma senegalense group sensu Häckel, 2012 (Coleoptera: Carabidae: Carabini). Conducted is a taxonomic revision of the Calosoma senegalense group sensu Häckel, 2012. Placed in the group sensu stricto are four species: Calosoma planicolle Chaudoir, 1869, Calosoma scabrosum Chaudoir, 1843, Calosoma senegalense Dejean, 1831, and Ctenosta strandi Breuning, 1934. Calosoma aethiops Jeannel, 1940 is synonymized with Calosoma imbricatum hottentotum Chaudoir, 1852, and Calosoma roeschkei Breuning, 1927 is newly regarded as a subspecies of Calosoma scabrosum. The taxonomic conclusions are based on morphometry of the holotypes and 10 male and 10 female specimens of each taxon, and on morphology of the aedeagus including inflated endophalus. PMID:27563269

  15. Isolation of live Borrelia burgdorferi sensu lato spirochaetes from patients with undefined disorders and symptoms not typical for Lyme borreliosis.

    PubMed

    Rudenko, N; Golovchenko, M; Vancova, M; Clark, K; Grubhoffer, L; Oliver, J H

    2016-03-01

    Lyme borreliosis is a multisystem disorder with a diverse spectrum of clinical manifestations, caused by spirochaetes of the Borrelia burgdorferi sensu lato complex. It is an infectious disease that can be successfully cured by antibiotic therapy in the early stages; however, the possibility of the appearance of persistent signs and symptoms of disease following antibiotic treatment is recognized. It is known that Lyme borreliosis mimics multiple diseases that were never proven to have a spirochaete aetiology. Using complete modified Kelly-Pettenkofer medium we succeeded in cultivating live B. burgdorferi sensu lato spirochaetes from samples taken from people who suffered from undefined disorders, had symptoms not typical for Lyme borreliosis, but who had undergone antibiotic treatment due to a suspicion of having Lyme disease even though they were seronegative. We report the first recovery of live B. burgdorferi sensu stricto from residents of southeastern USA and the first successful cultivation of live Borrelia bissettii-like strain from residents of North America. Our results support the fact that B. bissettii is responsible for human Lyme borreliosis worldwide along with B. burgdorferi s.s. The involvement of new spirochaete species in Lyme borreliosis changes the understanding and recognition of clinical manifestations of this disease. PMID:26673735

  16. Field responses of Anopheles gambiae complex (Diptera: Culicidae) in Liberia using yeast-generated carbon dioxide and synthetic lure-baited light traps.

    PubMed

    Obenauer, P J; Abdel-Dayem, M S; Stoops, C A; Villinski, J T; Tageldin, R; Fahmy, N T; Diclaro, J W; Bolay, F

    2013-07-01

    Malaria infection is a serious public health problem throughout Liberia, but vector surveillance is limited or nonexistent in remote regions of the country. To better understand the spatial and temporal distribution of malaria vectors in Liberia and to support vector and malaria activities of the Liberian Ministry of Health, a study was conducted to determine the efficacy of light traps baited with a synthetic lure and CO2 for capturing Anopheles gambiae sensu lato (Giles). Traps with a ultraviolet, light-emitting diode, and incandescent lights baited with a synthetic skin lure and CO2 combinations were evaluated at four field sites in three counties of Liberia for five consecutive nights every 8 wk during 2011. In total, 4,788 mosquitoes representing 56 species from nine genera were collected throughout the 30-wk study; An. gambiae s. l. comprised 32% and of the148 An. gambiae s. s. collected, 85% were of the S form. A greater percentage of An. gambiae s. l. were collected in ultraviolet traps baited with a synthetic lure and CO2 compared with any other trap configuration. The influence of trap configuration on conclusions from surveillance efforts, specifically with regards to An. gambiae is discussed. PMID:23926786

  17. Following in Soper's footsteps: northeast Brazil 63 years after eradication of Anopheles gambiae.

    PubMed

    Killeen, Gerry F

    2003-10-01

    Sub-Saharan Africa has long suffered under the yoke of the Anopheles gambiae mosquito, but for northeast Brazil (figure 1) its arrival over 60 years ago was a new and horrifying experience. This African mosquito is an exceptionally effective malaria vector because it is well adapted to feeding upon people and to exploiting aquatic habitats associated with our daily activities. Anopheles gambiae sensu lato probably accounts for most of the world's malaria deaths and socioeconomic burden. Fortunately, the Brazilian experience had a happy ending. The prospect of A gambiae spreading across much of the Americas motivated a ruthlessly effective response that deserves a special and heroic place in the annals of public health. Building on the successes and infrastructure of the Yellow Fever Service for Aedes aegypti elimination, the Rockefeller Foundation and Brazilian government collaborated to form a new Malaria Service of the Northeast. This new entity rolled the invader back into oblivion with an aggressive eradication campaign, focusing primarily upon larviciding of all potential habitats. The driving force of this endeavour was an enigmatic man called Fred Soper whose sheer will and determination was a key element in this success, and a source of inspiration today (see Killeen GF, et al. Eradication of Anopheles gambiae from Brazil: lessons for malaria control in Africa? Lancet Infect Dis 2002; 2: 618-27). I recently took an opportunity to fulfil a long-held dream and follow in some of Soper's footsteps. Tired of gazing at yellowing maps like figure 1, I went to see the northeast of Brazil for myself. PMID:14522266

  18. Neuropeptides and Peptide Hormones in Anopheles gambiae

    NASA Astrophysics Data System (ADS)

    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.

  19. Brain Proteomics of Anopheles gambiae

    PubMed Central

    Dwivedi, Sutopa B.; Muthusamy, Babylakshmi; Kumar, Praveen; Kim, Min-Sik; Nirujogi, Raja Sekhar; Getnet, Derese; Ahiakonu, Priscilla; De, Gourav; Nair, Bipin; Gowda, Harsha; Prasad, T.S. Keshava; Kumar, Nirbhay

    2014-01-01

    Abstract Anopheles gambiae has a well-adapted system for host localization, feeding, and mating behavior, which are all governed by neuronal processes in the brain. However, there are no published reports characterizing the brain proteome to elucidate neuronal signaling mechanisms in the vector. To this end, a large-scale mapping of the brain proteome of An. gambiae was carried out using high resolution tandem mass spectrometry, revealing a repertoire of >1800 proteins, of which 15% could not be assigned any function. A large proportion of the identified proteins were predicted to be involved in diverse biological processes including metabolism, transport, protein synthesis, and olfaction. This study also led to the identification of 10 GPCR classes of proteins, which could govern sensory pathways in mosquitoes. Proteins involved in metabolic and neural processes, chromatin modeling, and synaptic vesicle transport associated with neuronal transmission were predominantly expressed in the brain. Proteogenomic analysis expanded our findings with the identification of 15 novel genes and 71 cases of gene refinements, a subset of which were validated by RT-PCR and sequencing. Overall, our study offers valuable insights into the brain physiology of the vector that could possibly open avenues for intervention strategies for malaria in the future. PMID:24937107

  20. The Phylogeny of Bacillus cereus sensu lato.

    PubMed

    Okinaka, Richard T; Keim, Paul

    2016-02-01

    The three main species of the Bacillus cereus sensu lato, B. cereus, B. thuringiensis, and B. anthracis, were recognized and established by the early 1900 s because they each exhibited distinct phenotypic traits. B. thuringiensis isolates and their parasporal crystal proteins have long been established as a natural pesticide and insect pathogen. B. anthracis, the etiological agent for anthrax, was used by Robert Koch in the 19th century as a model to develop the germ theory of disease, and B. cereus, a common soil organism, is also an occasional opportunistic pathogen of humans. In addition to these three historical species designations, are three less-recognized and -understood species: B. mycoides, B. weihenstephanensis, and B. pseudomycoides. All of these "species" combined comprise the Bacillus cereus sensu lato group. Despite these apparently clear phenotypic definitions, early molecular approaches to separate the first three by various DNA hybridization and 16S/23S ribosomal sequence analyses led to some "confusion" because there were limited differences to differentiate between these species. These and other results have led to frequent suggestions that a taxonomic change was warranted to reclassify this group to a single species. But the pathogenic properties of B. anthracis and the biopesticide applications of B. thuringiensis appear to "have outweighed pure taxonomic considerations" and the separate species categories are still being maintained. B. cereus sensu lato represents a classic example of a now common bacterial species taxonomic quandary. PMID:26999390

  1. Borrelia burgdorferi sensu lato and co-infections with Anaplasma phagocytophilum and Rickettsia spp. in Ixodes ricinus in Hamburg, Germany.

    PubMed

    May, K; Jordan, D; Fingerle, V; Strube, C

    2015-12-01

    To obtain initial data on Borrelia burgdorferi sensu lato (Spirochaetales: Spirochaetaceae) in Ixodes ricinus (Ixodida: Ixodidae) ticks in Hamburg, Germany, 1400 questing ticks were collected by flagging at 10 different public recreation areas in 2011 and analysed using probe-based quantitative real-time polymerase chain reaction. The overall rate of infection with B. burgdorferi s.l. was 34.1%; 30.0% of adults were infected (36.7% of females and 26.0% of males), as were 34.5% of nymphs. Significant differences in tick infection rates were observed between the spring and summer/autumn months, as well as among sampling locations. Borrelia genospecies identification by reverse line blotting was successful in 43.6% of positive tick samples. The most frequent genospecies was Borrelia garinii/Borrelia bavariensis, followed by Borrelia afzelii, Borrelia valaisiana, B. burgdorferi sensu stricto, Borrelia spielmanii, Borrelia bissettii and Borrelia lusitaniae. Based on previously published data, co-infection of Borrelia and Rickettsiales spp. was determined in 25.8% of ticks. Overall, 22.9% of ticks were co-infected with Rickettsia spp. (Rickettsiales: Rickettsiaceae), 1.7% with Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae), and 1.2% with both pathogens. Study results show a high prevalence of Borrelia-positive ticks in recreation areas in the northern German city of Hamburg and the potential health risk to humans in these areas should not be underestimated. PMID:26096626

  2. Presence of host-seeking Ixodes ricinus and their infection with Borrelia burgdorferi sensu lato in the Northern Apennines, Italy.

    PubMed

    Ragagli, Charlotte; Mannelli, Alessandro; Ambrogi, Cecilia; Bisanzio, Donal; Ceballos, Leonardo A; Grego, Elena; Martello, Elisa; Selmi, Marco; Tomassone, Laura

    2016-06-01

    Host-seeking ticks were collected in the Northern Apennines, Italy, by dragging at 35 sites, at altitudes ranging from 680 and 1670 m above sea level (asl), from April to November, in 2010 and 2011. Ixodes ricinus (4431 larvae, 597 nymphs and 12 adults) and Haemaphysalis punctata (11,209 larvae, 313 nymphs, and 25 adults) were the most abundant species, followed by Haemaphysalis sulcata (20 larvae, five nymphs, and 13 adults), Dermacentor marginatus (42 larvae and two adults) and Ixodes hexagonus (one nymph). Greatest numbers of ticks were collected at locations characterised by southern exposure and limestone substratum, at altitudes <1400 m asl; I. ricinus was most abundant in Turkey oak (Quercus cerris) wood, whereas H. punctata was mostly collected in hop hornbeam (Ostrya carpinifolia) wood and on exposed rocks. Ixodes ricinus was also found up to 1670 m asl, in high stand beech (Fagus sylvatica) wood. The overall prevalence of Borrelia burgdorferi sensu lato (sl) in 294 host-seeking I. ricinus nymphs was 8.5 %. Borrelia garinii was the most frequently identified genospecies (64.0 % of positive nymphs), followed by B. valaisiana, B. burgdorferi sensu stricto, B. afzelii, and B. lusitaniae. Based upon the comparison with the results of previous studies at the same location, these research findings suggest the recent invasion of the study area by the tick vector and the agents of Lyme borreliosis. PMID:26964552

  3. Multiple insecticide resistance in Anopheles gambiae (Diptera: Culicidae) from Pointe Noire, Republic of the Congo.

    PubMed

    Koekemoer, Lizette L; Spillings, Belinda L; Christian, Riann N; Lo, Te-Chang M; Kaiser, Maria L; Norton, Ryan A I; Oliver, Shune V; Choi, Kwang S; Brooke, Basil D; Hunt, Richard H; Coetzee, Maureen

    2011-08-01

    Successful implementation of an integrated vector control program will rely on availability of accurate vector information in the specific location. However, such information can be limited in some countries. The aim of this study was to obtain baseline vector information from Pointe Noire on the Congo coast (Republic of the Congo). Field sampling was conducted during April 2009 in the village of Boutoto and its surrounds, close to the city of Pointe Noire. Anopheles gambiae sensu lato mosquitoes were collected resting indoors. Samples were analyzed for insecticide susceptibility, species identification, and Plasmodium sporozoite infection. Molecular and biochemical assays were conducted to characterize insecticide resistance mechanisms. The malaria vector A. gambiae S-form was the only mosquito species identified, and it had a high Plasmodium falciparum infection rate (9.6%). Multiple insecticide resistance was detected in this population with full susceptibility to only one insecticide class, the organophosphates. Dieldrin and DDT resistance was mainly attributed to target-site resistance (the Rdl and L1014F/L1014S kdr mutations respectively), whereas pyrethroid resistance was mainly attributed to P450 metabolic enzyme-mediated detoxification in addition to kdr. The role of various insecticide resistance mechanisms revealed a complex association between metabolic detoxification and reduced target-site sensitivity. PMID:21417925

  4. Echinococcus granulosus sensu lato GENOTYPES IN DOMESTIC LIVESTOCK AND HUMANS IN GOLESTAN PROVINCE, IRAN.

    PubMed

    Sharbatkhori, Mitra; Tanzifi, Asal; Rostami, Sima; Rostami, Masoomeh; Fasihi Harandi, Majid

    2016-01-01

    Cystic echinococcosis (CE) is a globally parasitic zoonosis caused by larval stages of Echinococcus granulosus. This study investigated E. granulosus genotypes isolated from livestock and humans in the Golestan province, northern Iran, southeast of the Caspian sea, using partial sequencing data of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase 1 (nad1) mitochondrial genes. Seventy E. granulosus isolates were collected from animals in slaughterhouses: 18 isolates from sheep, 40 from cattle, nine from camels, two from buffaloes and one from a goat, along with four human isolates (formalin-fixed, paraffin-embedded tissues) from CE patients of provincial hospitals. All isolates were successfully analysed by PCR amplification and sequencing. The sequence analysis found four E. granulosus genotypes among the 74 CE isolates: G1 (78.3%), G2 (2.7%), G3 (15%) and G6 (4%). The G1-G3 complex genotype was found in all of the sheep, goat, cattle and buffalo isolates. Among the nine camel isolates, the frequency of G1-G3 and G6 genotypes were 66.7% and 33.3%, respectively. All four human CE isolates belonged to E. granulosus sensu stricto. This study reports the first occurrence of the G2 genotype in cattle from Iran and confirms the previously reported G3 genotype in camels in the same country. PMID:27253740

  5. Echinococcus granulosus sensu lato GENOTYPES IN DOMESTIC LIVESTOCK AND HUMANS IN GOLESTAN PROVINCE, IRAN

    PubMed Central

    SHARBATKHORI, Mitra; TANZIFI, Asal; ROSTAMI, Sima; ROSTAMI, Masoomeh; HARANDI, Majid FASIHI

    2016-01-01

    Cystic echinococcosis (CE) is a globally parasitic zoonosis caused by larval stages of Echinococcus granulosus. This study investigated E. granulosus genotypes isolated from livestock and humans in the Golestan province, northern Iran, southeast of the Caspian sea, using partial sequencing data of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase 1 (nad1) mitochondrial genes. Seventy E. granulosus isolates were collected from animals in slaughterhouses: 18 isolates from sheep, 40 from cattle, nine from camels, two from buffaloes and one from a goat, along with four human isolates (formalin-fixed, paraffin-embedded tissues) from CE patients of provincial hospitals. All isolates were successfully analysed by PCR amplification and sequencing. The sequence analysis found four E. granulosus genotypes among the 74 CE isolates: G1 (78.3%), G2 (2.7%), G3 (15%) and G6 (4%). The G1-G3 complex genotype was found in all of the sheep, goat, cattle and buffalo isolates. Among the nine camel isolates, the frequency of G1-G3 and G6 genotypes were 66.7% and 33.3%, respectively. All four human CE isolates belonged to E. granulosus sensu stricto. This study reports the first occurrence of the G2 genotype in cattle from Iran and confirms the previously reported G3 genotype in camels in the same country. PMID:27253740

  6. Tools for Anopheles gambiae Transgenesis

    PubMed Central

    Volohonsky, Gloria; Terenzi, Olivier; Soichot, Julien; Naujoks, Daniel A.; Nolan, Tony; Windbichler, Nikolai; Kapps, Delphine; Smidler, Andrea L.; Vittu, Anaïs; Costa, Giulia; Steinert, Stefanie; Levashina, Elena A.; Blandin, Stéphanie A.; Marois, Eric

    2015-01-01

    Transgenesis is an essential tool to investigate gene function and to introduce desired characters in laboratory organisms. Setting-up transgenesis in non-model organisms is challenging due to the diversity of biological life traits and due to knowledge gaps in genomic information. Some procedures will be broadly applicable to many organisms, and others have to be specifically developed for the target species. Transgenesis in disease vector mosquitoes has existed since the 2000s but has remained limited by the delicate biology of these insects. Here, we report a compilation of the transgenesis tools that we have designed for the malaria vector Anopheles gambiae, including new docking strains, convenient transgenesis plasmids, a puromycin resistance selection marker, mosquitoes expressing cre recombinase, and various reporter lines defining the activity of cloned promoters. This toolbox contributed to rendering transgenesis routine in this species and is now enabling the development of increasingly refined genetic manipulations such as targeted mutagenesis. Some of the reagents and procedures reported here are easily transferable to other nonmodel species, including other disease vector or agricultural pest insects. PMID:25869647

  7. PEANUT SHELL FUEL FOR THE GAMBIA

    EPA Science Inventory

    The project will develop a household-scale human-powered briquette maker that will convert peanut shells into an efficient cooking fuel. The briquette maker will be designed such that it can be manufactured and used in The Gambia.

  8. Borrelia burgdorferi Sensu Lato Spirochetes in Wild Birds in Northwestern California: Associations with Ecological Factors, Bird Behavior and Tick Infestation

    PubMed Central

    Newman, Erica A.; Eisen, Lars; Eisen, Rebecca J.; Fedorova, Natalia; Hasty, Jeomhee M.; Vaughn, Charles; Lane, Robert S.

    2015-01-01

    Although Borrelia burgdorferi sensu lato (s.l.) are found in a great diversity of vertebrates, most studies in North America have focused on the role of mammals as spirochete reservoir hosts. We investigated the roles of birds as hosts for subadult Ixodes pacificus ticks and potential reservoirs of the Lyme disease spirochete B. burgdorferi sensu stricto (s.s.) in northwestern California. Overall, 623 birds representing 53 species yielded 284 I. pacificus larvae and nymphs. We used generalized linear models and zero-inflated negative binomial models to determine associations of bird behaviors, taxonomic relationships and infestation by I. pacificus with borrelial infection in the birds. Infection status in birds was best explained by taxonomic order, number of infesting nymphs, sampling year, and log-transformed average body weight. Presence and counts of larvae and nymphs could be predicted by ground- or bark-foraging behavior and contact with dense oak woodland. Molecular analysis yielded the first reported detection of Borrelia bissettii in birds. Moreover, our data suggest that the Golden-crowned Sparrow (Zonotrichia atricapilla), a non-resident species, could be an important reservoir for B. burgdorferi s.s. Of 12 individual birds (9 species) that carried B. burgdorferi s.l.-infected larvae, no birds carried the same genospecies of B. burgdorferi s.l. in their blood as were present in the infected larvae removed from them. Possible reasons for this discrepancy are discussed. Our study is the first to explicitly incorporate both taxonomic relationships and behaviors as predictor variables to identify putative avian reservoirs of B. burgdorferi s.l. Our findings underscore the importance of bird behavior to explain local tick infestation and Borrelia infection in these animals, and suggest the potential for bird-mediated geographic spread of vector ticks and spirochetes in the far-western United States. PMID:25714376

  9. Large Scale Spatial Risk and Comparative Prevalence of Borrelia miyamotoi and Borrelia burgdorferi Sensu Lato in Ixodes pacificus

    PubMed Central

    Padgett, Kerry; Bonilla, Denise; Kjemtrup, Anne; Vilcins, Inger-Marie; Yoshimizu, Melissa Hardstone; Hui, Lucia; Sola, Milagros; Quintana, Miguel; Kramer, Vicki

    2014-01-01

    Borrelia miyamotoi is a newly described emerging pathogen transmitted to people by Ixodes species ticks and found in temperate regions of North America, Europe, and Asia. There is limited understanding of large scale entomological risk patterns of B. miyamotoi and of Borreila burgdorferi sensu stricto (ss), the agent of Lyme disease, in western North America. In this study, B. miyamotoi, a relapsing fever spirochete, was detected in adult (n = 70) and nymphal (n = 36) Ixodes pacificus ticks collected from 24 of 48 California counties that were surveyed over a 13 year period. Statewide prevalence of B. burgdorferi sensu lato (sl), which includes B. burgdorferi ss, and B. miyamotoi were similar in adult I. pacificus (0.6% and 0.8%, respectively). In contrast, the prevalence of B. burgdorferi sl was almost 2.5 times higher than B. miyamotoi in nymphal I. pacificus (3.2% versus 1.4%). These results suggest similar risk of exposure to B. burgdorferi sl and B. miyamotoi from adult I. pacificus tick bites in California, but a higher risk of contracting B. burgdorferi sl than B. miyamotoi from nymphal tick bites. While regional risk of exposure to these two spirochetes varies, the highest risk for both species is found in north and central coastal California and the Sierra Nevada foothill region, and the lowest risk is in southern California; nevertheless, tick-bite avoidance measures should be implemented in all regions of California. This is the first study to comprehensively evaluate entomologic risk for B. miyamotoi and B. burgdorferi for both adult and nymphal I. pacificus, an important human biting tick in western North America. PMID:25333277

  10. Inter- and intra-specific pan-genomes of Borrelia burgdorferi sensu lato: genome stability and adaptive radiation

    PubMed Central

    2013-01-01

    Background Lyme disease is caused by spirochete bacteria from the Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) species complex. To reconstruct the evolution of B. burgdorferi s.l. and identify the genomic basis of its human virulence, we compared the genomes of 23 B. burgdorferi s.l. isolates from Europe and the United States, including B. burgdorferi sensu stricto (B. burgdorferi s.s., 14 isolates), B. afzelii (2), B. garinii (2), B. “bavariensis” (1), B. spielmanii (1), B. valaisiana (1), B. bissettii (1), and B. “finlandensis” (1). Results Robust B. burgdorferi s.s. and B. burgdorferi s.l. phylogenies were obtained using genome-wide single-nucleotide polymorphisms, despite recombination. Phylogeny-based pan-genome analysis showed that the rate of gene acquisition was higher between species than within species, suggesting adaptive speciation. Strong positive natural selection drives the sequence evolution of lipoproteins, including chromosomally-encoded genes 0102 and 0404, cp26-encoded ospC and b08, and lp54-encoded dbpA, a07, a22, a33, a53, a65. Computer simulations predicted rapid adaptive radiation of genomic groups as population size increases. Conclusions Intra- and inter-specific pan-genome sizes of B. burgdorferi s.l. expand linearly with phylogenetic diversity. Yet gene-acquisition rates in B. burgdorferi s.l. are among the lowest in bacterial pathogens, resulting in high genome stability and few lineage-specific genes. Genome adaptation of B. burgdorferi s.l. is driven predominantly by copy-number and sequence variations of lipoprotein genes. New genomic groups are likely to emerge if the current trend of B. burgdorferi s.l. population expansion continues. PMID:24112474

  11. The Heterogeneity, Distribution, and Environmental Associations of Borrelia burgdorferi Sensu Lato, the Agent of Lyme Borreliosis, in Scotland

    PubMed Central

    James, Marianne C.; Gilbert, Lucy; Bowman, Alan S.; Forbes, Ken J.

    2014-01-01

    Lyme borreliosis is an emerging infectious human disease caused by the Borrelia burgdorferi sensu lato complex of bacteria with reported cases increasing in many areas of Europe and North America. To understand the drivers of disease risk and the distribution of symptoms, which may improve mitigation and diagnostics, here we characterize the genetics, distribution, and environmental associations of B. burgdorferi s.l. genospecies across Scotland. In Scotland, reported Lyme borreliosis cases have increased almost 10-fold since 2000 but the distribution of B. burgdorferi s.l. is so far unstudied. Using a large survey of over 2200 Ixodes ricinus tick samples collected from birds, mammals, and vegetation across 25 sites we identified four genospecies: Borrelia afzelii (48%), Borrelia garinii (36%), Borrelia valaisiana (8%), and B. burgdorferi sensu stricto (7%), and one mixed genospecies infection. Surprisingly, 90% of the sequence types were novel and, importantly, up to 14% of samples were mixed intra-genospecies co-infections, suggesting tick co-feeding, feeding on multiple hosts, or multiple infections in hosts. B. garinii (hosted by birds) was considerably more genetically diverse than B. afzelii (hosted by small mammals), as predicted since there are more species of birds than small mammals and birds can import strains from mainland Europe. Higher proportions of samples contained B. garinii and B. valaisiana in the west, while B. afzelii and B. garinii were significantly more associated with mixed/deciduous than with coniferous woodlands. This may relate to the abundance of transmission hosts in different regions and habitats. These data on the genetic heterogeneity within and between Borrelia genospecies are a first step to understand pathogen spread and could help explain the distribution of patient symptoms, which may aid local diagnosis. Understanding the environmental associations of the pathogens is critical for rational policy making for disease risk

  12. Environmental Contamination by Echinococcus granulosus sensu lato Eggs in Relation to Slaughterhouses in Urban and Rural Areas in Tunisia.

    PubMed

    Chaâbane-Banaoues, Raja; Oudni-M'rad, Myriam; M'rad, Selim; Mezhoud, Habib; Babba, Hamouda

    2016-02-01

    Hydatidosis has become a real concern for health care institutions and animal rearers in Tunisia. The Tunisian endemicity is aggravated by the growing number of dogs and the difficulty of getting rid of contaminated viscera because of the lack of equipment in most slaughterhouses. Therefore, microscopic and molecular tools were applied to evaluate the role of slaughterhouses in canine infection and Echinococcus granulosus sensu lato (s. l.) egg dissemination. Exposure risk to E. granulosus s. l. eggs in urban and rural areas was explored in order to implant preventive and adapted control strategies. Microscopic examinations detected taeniid eggs in 152 amongst 553 fecal samples. The copro-PCR demonstrated that 138 of 152 taeniid samples analyzed were positive for E. granulosus s. l. DNA. PCR-RFLP demonstrated that all isolated samples belonged to E. granulosus sensu stricto (s. s.). An important environmental contamination index (25.0%) by E. granulosus s. l. eggs was demonstrated. The average contamination index from the regions around slaughterhouses (23.3%; 95% CI: 17.7-28.9%) was in the same range as detected in areas located far from slaughterhouses (26.0%, 95% CI: 21.3-30.8%). Echinococcosis endemic areas were extended in both rural (29.9%, 95% CI: 24.8-34.9%) and urban locations (18.1%, 95% CI: 13.0-22.9%). The pathogen dissemination is related neither to the presence/absence of slaughterhouses nor to the location in urban or rural areas, but is probably influenced by human activities (home slaughtering) and behavior towards the infected viscera. PMID:26951990

  13. Environmental Contamination by Echinococcus granulosus sensu lato Eggs in Relation to Slaughterhouses in Urban and Rural Areas in Tunisia

    PubMed Central

    Chaâbane-Banaoues, Raja; Oudni-M’rad, Myriam; M’rad, Selim; Mezhoud, Habib; Babba, Hamouda

    2016-01-01

    Hydatidosis has become a real concern for health care institutions and animal rearers in Tunisia. The Tunisian endemicity is aggravated by the growing number of dogs and the difficulty of getting rid of contaminated viscera because of the lack of equipment in most slaughterhouses. Therefore, microscopic and molecular tools were applied to evaluate the role of slaughterhouses in canine infection and Echinococcus granulosus sensu lato (s. l.) egg dissemination. Exposure risk to E. granulosus s. l. eggs in urban and rural areas was explored in order to implant preventive and adapted control strategies. Microscopic examinations detected taeniid eggs in 152 amongst 553 fecal samples. The copro-PCR demonstrated that 138 of 152 taeniid samples analyzed were positive for E. granulosus s. l. DNA. PCR-RFLP demonstrated that all isolated samples belonged to E. granulosus sensu stricto (s. s.). An important environmental contamination index (25.0%) by E. granulosus s. l. eggs was demonstrated. The average contamination index from the regions around slaughterhouses (23.3%; 95% CI: 17.7-28.9%) was in the same range as detected in areas located far from slaughterhouses (26.0%, 95% CI: 21.3-30.8%). Echinococcosis endemic areas were extended in both rural (29.9%, 95% CI: 24.8-34.9%) and urban locations (18.1%, 95% CI: 13.0-22.9%). The pathogen dissemination is related neither to the presence/absence of slaughterhouses nor to the location in urban or rural areas, but is probably influenced by human activities (home slaughtering) and behavior towards the infected viscera. PMID:26951990

  14. Molasses as a source of carbon dioxide for attracting the malaria mosquitoes Anopheles gambiae and Anopheles funestus

    PubMed Central

    2014-01-01

    Background Most odour baits for haematophagous arthropods contain carbon dioxide (CO2). The CO2 is sourced artificially from the fermentation of refined sugar (sucrose), dry ice, pressurized gas cylinders or propane. These sources of CO2 are neither cost-effective nor sustainable for use in remote areas of sub-Saharan Africa. In this study, molasses was evaluated as a potential substrate for producing CO2 used as bait for malaria mosquitoes. Methods The attraction of laboratory-reared and wild Anopheles gambiae complex mosquitoes to CO2 generated from yeast-fermentation of molasses was assessed under semi-field and field conditions in western Kenya. In the field, responses of wild Anopheles funestus were also assessed. Attraction of the mosquitoes to a synthetic mosquito attractant, Mbita blend (comprising ammonia, L-lactic acid, tetradecanoic acid and 3-methyl-1-butanol) when augmented with CO2 generated from yeast fermentation of either molasses or sucrose was also investigated. Results In semi-field, the release rate of CO2 and proportion of An. gambiae mosquitoes attracted increased in tandem with an increase in the quantity of yeast-fermented molasses up to an optimal ratio of molasses and dry yeast. More An. gambiae mosquitoes were attracted to a combination of the Mbita blend plus CO2 produced from fermenting molasses than the Mbita blend plus CO2 from yeast-fermented sucrose. In the field, significantly more female An. gambiae sensu lato mosquitoes were attracted to the Mbita blend augmented with CO2 produced by fermenting 500 g of molasses compared to 250 g of sucrose or 250 g of molasses. Similarly, significantly more An. funestus, Culex and other anopheline mosquito species were attracted to the Mbita blend augmented with CO2 produced from fermenting molasses than the Mbita blend with CO2 produced from sucrose. Augmenting the Mbita blend with CO2 produced from molasses was associated with high catches of blood-fed An. gambiae s.l. and An. funestus

  15. Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia

    PubMed Central

    Jawara, Musa; Pinder, Margaret; Drakeley, Chris J; Nwakanma, Davis C; Jallow, Ebrima; Bogh, Claus; Lindsay, Steve W; Conway, David J

    2008-01-01

    Background Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. Methods Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores), and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June). Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. Results Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%), with An. gambiae s.s. (10%) and An. arabiensis (3%) also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709) contained sporozoites. Larvae (mostly An. gambiae s.s.) were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. Conclusion During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative numbers of An. gambiae s

  16. Human seroprevalence against Borrelia burgdorferi sensu lato in two comparable regions of the eastern Alps is not correlated to vector infection rates.

    PubMed

    Sonnleitner, S T; Margos, G; Wex, F; Simeoni, J; Zelger, R; Schmutzhard, E; Lass-Flörl, C; Walder, G

    2015-04-01

    Seroprevalences were determined by testing sera of 1607 blood donors from North, East, and South Tyrol. In the Tyrols, the continental divide delimitates areas with high seroprevalences of IgG antibodies against Borrelia burgdorferi sensu lato in the North (7.2%) from areas with low seroprevalences in the South (1.5%). To determine Borrelia prevalences in unfed Ixodes ricinus ticks, 755 questing ticks were tested by PCR. Prevalences in nymphal and adult ticks were found to be 19.7% (n=132) and 21.5% (n=205) in North Tyrol and 23% (n=43) and 23.7% (n=376) in South Tyrol, respectively. Sequencing of 46 Borrelia-positive ticks yielded 74% Borrelia (B.) afzelii, 11% B. garinii, 7% B. lusitaniae, 7% B. burgdorferi sensu stricto, and 2% B. valaisiana infections. Distinct genetic clusters could not be delimitated on either side of the continental divide. This study describes occurrence and geographic dispersion of Borrelia spp. in the Tyrols, discusses possible reasons for significant differences in human seroprevalence, and indicates that prevalence of Borrelia in vector ticks is not a direct predictive factor for the local seroprevalence in humans. PMID:25661649

  17. Development of a multiplex real-time PCR assay for identification of members of the Anopheles gambiae species complex.

    PubMed

    Bass, Chris; Williamson, Martin S; Field, Linda M

    2008-07-01

    Two high-throughput assays for the identification of members of the Anopheles gambiae sensu lato species complex have recently been reported. These methods, are based on TaqMan single nucleotide polymorphism (SNP) genotyping that enables rapid scoring of mosquito DNA samples in real-time PCR reactions. Unfortunately, both assays are restricted in the number of species that they can identify and a combination of the two assays may be required to identify all possible species in certain regions. To overcome this limitation, and thereby further increase throughput while reducing costs, we have developed a new multiplex real-time PCR assay for identifying members of the An. gambiae complex. The new method uses three probes labelled with fluorophores with distinct emission and excitation spectra, allowing simultaneous detection of the two main malaria vectors from the non-vector sibling species, and can be used on single mosquito legs from silica-dried specimens. A genotyping trial of over 450 specimens collected from 13 countries in sub-Saharan Africa showed the multiplex assay to be highly specific and sensitive and it compared well against the two previously reported TaqMan assays and standard allele-specific PCR. PMID:18490000

  18. Application of a qPCR Assay in the Investigation of Susceptibility to Malaria Infection of the M and S Molecular Forms of An. gambiae s.s. in Cameroon

    PubMed Central

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

    2013-01-01

    Plasmodium falciparum is the causative agent of malaria, a disease that kills almost one million persons each year, mainly in sub-Saharan Africa. P. falciparum is transmitted to the human host by the bite of an Anopheles female mosquito, and Anopheles gambiae sensus stricto is the most tremendous malaria vector in Africa, widespread throughout the afro-tropical belt. An. gambiae s.s. is subdivided into two distinct molecular forms, namely M and S forms. The two molecular forms are morphologically identical but they are distinct genetically, and differ by their distribution and their ecological preferences. The epidemiological importance of the two molecular forms in malaria transmission has been poorly investigated so far and gave distinct results in different areas. We have developed a real-time quantitative PCR (qPCR) assay, and used it to detect P. falciparum at the oocyst stage in wild An. gambiae s.s. mosquitoes experimentally infected with natural isolates of parasites. Mosquitoes were collected at immature stages in sympatric and allopatric breeding sites and further infected at the adult stage. We next measured the infection prevalence and intensity in female mosquitoes using the qPCR assay and correlated the infection success with the mosquito molecular forms. Our results revealed different prevalence of infection between the M and S molecular forms of An. gambiae s.s. in Cameroon, for both sympatric and allopatric populations of mosquitoes. However, no difference in the infection intensity was observed. Thus, the distribution of the molecular forms of An. gambiae s.s. may impact on the malaria epidemiology, and it will be important to monitor the efficiency of malaria control interventions on the two M and S forms. PMID:23349974

  19. Divergence of Borrelia burgdorferi sensu lato spirochetes could be driven by the host: diversity of Borrelia strains isolated from ticks feeding on a single bird

    PubMed Central

    2014-01-01

    Background The controversy surrounding the potential impact of birds in spirochete transmission dynamics and their capacity to serve as a reservoir has existed for a long time. The majority of analyzed bird species are able to infect larval ticks with Borrelia. Dispersal of infected ticks due to bird migration is a key to the establishment of new foci of Lyme borreliosis. The dynamics of infection in birds supports the mixing of different species, the horizontal exchange of genetic information, and appearance of recombinant genotypes. Methods Four Borrelia burgdorferi sensu lato strains were cultured from Ixodes minor larvae and four strains were isolated from Ixodes minor nymphs collected from a single Carolina Wren (Thryothorus ludovicianus). A multilocus sequence analysis that included 16S rRNA, a 5S-23S intergenic spacer region, a 16S-23S internal transcribed spacer, flagellin, p66, and ospC separated 8 strains into 3 distinct groups. Additional multilocus sequence typing of 8 housekeeping genes, clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA was used to resolve the taxonomic status of bird-associated strains. Results Results of analysis of 14 genes confirmed that the level of divergence among strains is significantly higher than what would be expected for strains within a single species. The presence of cross-species recombination was revealed: Borrelia burgdorferi sensu stricto housekeeping gene nifS was incorporated into homologous locus of strain, previously assigned to B. americana. Conclusions Genetically diverse Borrelia strains are often found within the same tick or same vertebrate host, presenting a wide opportunity for genetic exchange. We report the cross-species recombination that led to incorporation of a housekeeping gene from the B. burgdorferi sensu stricto strain into a homologous locus of another bird-associated strain. Our results support the hypothesis that recombination maintains a majority of sequence polymorphism within Borrelia

  20. Elimination of Lymphatic Filariasis in The Gambia

    PubMed Central

    Rebollo, Maria P.; Sambou, Sana Malang; Thomas, Brent; Biritwum, Nana-Kwadwo; Jaye, Momodou C.; Kelly-Hope, Louise; Escalada, Alba Gonzalez; Molyneux, David H.; Bockarie, Moses J.

    2015-01-01

    Background The prevalence of Wuchereria bancrofti, which causes lymphatic filariasis (LF) in The Gambia was among the highest in Africa in the 1950s. However, surveys conducted in 1975 and 1976 revealed a dramatic decline in LF endemicity in the absence of mass drug administration (MDA). The decline in prevalence was partly attributed to a significant reduction in mosquito density through the widespread use of insecticidal nets. Based on findings elsewhere that vector control alone can interrupt LF, we asked the question in 2013 whether the rapid scale up in the use of insecticidal nets in The Gambia had interrupted LF transmission. Methodology/Principal Finding We present here the results of three independently designed filariasis surveys conducted over a period of 17 years (1997–2013), and involving over 6000 subjects in 21 districts across all administrative divisions in The Gambia. An immunochromatographic (ICT) test was used to detect W. bancrofti antigen during all three surveys. In 2001, tests performed on stored samples collected between 1997 and 2000, in three divisions, failed to show positive individuals from two divisions that were previously highly endemic for LF, suggesting a decline towards extinction in some areas. Results of the second survey conducted in 2003 showed that LF was no longer endemic in 16 of 21 districts surveyed. The 2013 survey used a WHO recommended LF transmission verification tool involving 3180 6–7 year-olds attending 60 schools across the country. We demonstrated that transmission of W. bancrofti has been interrupted in all 21 districts. Conclusions We conclude that LF transmission may have been interrupted in The Gambia through the extensive use of insecticidal nets for malaria control for decades. The growing evidence for the impact of malaria vector control activities on parasite transmission has been endorsed by WHO through a position statement in 2011 on integrated vector management to control malaria and LF. PMID

  1. Characterization, Ecological Distribution, and Population Dynamics of Saccharomyces Sensu Stricto Killer Yeasts in the Spontaneous Grape Must Fermentations of Southwestern Spain

    PubMed Central

    Maqueda, Matilde; Zamora, Emiliano; Álvarez, María L.

    2012-01-01

    Killer yeasts secrete protein toxins that are lethal to sensitive strains of the same or related yeast species. Among the four types of Saccharomyces killer yeasts already described (K1, K2, K28, and Klus), we found K2 and Klus killer yeasts in spontaneous wine fermentations from southwestern Spain. Both phenotypes were encoded by medium-size double-stranded RNA (dsRNA) viruses, Saccharomyces cerevisiae virus (ScV)-M2 and ScV-Mlus, whose genome sizes ranged from 1.3 to 1.75 kb and from 2.1 to 2.3 kb, respectively. The K2 yeasts were found in all the wine-producing subareas for all the vintages analyzed, while the Klus yeasts were found in the warmer subareas and mostly in the warmer ripening/harvest seasons. The middle-size isotypes of the M2 dsRNA were the most frequent among K2 yeasts, probably because they encoded the most intense K2 killer phenotype. However, the smallest isotype of the Mlus dsRNA was the most frequent for Klus yeasts, although it encoded the least intense Klus killer phenotype. The killer yeasts were present in most (59.5%) spontaneous fermentations. Most were K2, with Klus being the minority. The proportion of killer yeasts increased during fermentation, while the proportion of sensitive yeasts decreased. The fermentation speed, malic acid, and wine organoleptic quality decreased in those fermentations where the killer yeasts replaced at least 15% of a dominant population of sensitive yeasts, while volatile acidity and lactic acid increased, and the amount of bacteria in the tumultuous and the end fermentation stages also increased in an unusual way. PMID:22101056

  2. Definition of Tenuipalpus sensu stricto (Acari, Tenuipalpidae), with redescription of Tenuipalpus caudatus (Dugès) and description of a new species from Costa Rica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We discuss the taxonomic history of the genus Tenuipalpus Donnadieu and re-describe Tenuipalpus caudatus (Dugès) (= T. palmatus Donnadieu) based on specimens from Portugal intercepted at the United States ports of entry, and references including photographic records of the neotype of T. caudatus. In...

  3. Heterogeneity of Borrelia burgdorferi Sensu Stricto Population and Its Involvement in Borrelia Pathogenicity: Study on Murine Model with Specific Emphasis on the Skin Interface

    PubMed Central

    Kern, Aurélie; Schnell, Gilles; Bernard, Quentin; Bœuf, Amandine; Jaulhac, Benoît; Collin, Elody; Barthel, Cathy

    2015-01-01

    Lyme disease is a multisystemic disorder caused by B. burgdorferi sl. The molecular basis for specific organ involvement is poorly understood. The skin plays a central role in the development of Lyme disease as the entry site of B. burgdorferi in which specific clones are selected before dissemination. We compared the skin inflammatory response (antimicrobial peptides, cytokines and chemokines) elicited by spirochete populations recovered from patients presenting different clinical manifestations. Remarkably, these spirochete populations induced different inflammatory profiles in the skin of C3H/HeN mice. As spirochete population transmitted into the host skin is heterogeneous, we isolated one bacterial clone from a population recovered from a patient with neuroborreliosis and compared its virulence to the parental population. This clone elicited a strong cutaneous inflammatory response characterized by MCP-1, IL-6 and antimicrobial peptides induction. Mass spectrometry of this clone revealed 110 overexpressed proteins when compared with the parental population. We further focused on the expression of nine bacterial surface proteins. bb0347 coding for a protein that interacts with host fibronectin, allowing bacterial adhesion to vascular endothelium and extracellular matrix, was found to be induced in host skin with another gene bb0213 coding for a hypothetical protein. These findings demonstrate the heterogeneity of the B. burgdorferi ss population and the complexity of the interaction involved early in the skin. PMID:26197047

  4. Review of Apanteles sensu stricto (Hymenoptera: Braconidae, Microgastrinae) from Area de Conservación Guanacaste, northwestern Costa Rica, with keys to all described species from Mesoamerica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than half a million specimens of wild-caught Lepidoptera caterpillars have been reared for their parasitoids, identification, and DNA barcoding over a period of 34 years (and ongoing) from Area de Conservación de Guanacaste (ACG), northwestern Costa Rica. This provides the world’s best place-ba...

  5. Constructing a Species Database and Historic Range Maps for North American Bumble Bees (Bombus sensu stricto Latreille) to Inform Conservation Decisions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bumble bees (Bombus Latrielle) are some of the most important native pollinators in North America, pollinating both wild flowers and agricultural crops often where other pollinators such as honey bees are absent. In the last decade at least six North American species of bumble bees (Bombus Latreill...

  6. Application of DNA bar codes for screening of industrially important fungi: the haplotype of Trichoderma harzianum sensu stricto indicates superior chitinase formation.

    PubMed

    Nagy, Viviana; Seidl, Verena; Szakacs, George; Komoń-Zelazowska, Monika; Kubicek, Christian P; Druzhinina, Irina S

    2007-11-01

    Selection of suitable strains for biotechnological purposes is frequently a random process supported by high-throughput methods. Using chitinase production by Hypocrea lixii/Trichoderma harzianum as a model, we tested whether fungal strains with superior enzyme formation may be diagnosed by DNA bar codes. We analyzed sequences of two phylogenetic marker loci, internal transcribed spacer 1 (ITS1) and ITS2 of the rRNA-encoding gene cluster and the large intron of the elongation factor 1-alpha gene, tef1, from 50 isolates of H. lixii/T. harzianum, which were also tested to determine their ability to produce chitinases in solid-state fermentation (SSF). Statistically supported superior chitinase production was obtained for strains carrying one of the observed ITS1 and ITS2 and tef1 alleles corresponding to an allele of T. harzianum type strain CBS 226.95. A tef1-based DNA bar code tool, TrichoCHIT, for rapid identification of these strains was developed. The geographic origin of the strains was irrelevant for chitinase production. The improved chitinase production by strains containing this haplotype was not due to better growth on N-acetyl-beta-D-glucosamine or glucosamine. Isoenzyme electrophoresis showed that neither the isoenzyme profile of N-acetyl-beta-glucosaminidases or the endochitinases nor the intensity of staining of individual chitinase bands correlated with total chitinase in the culture filtrate. The superior chitinase producers did not exhibit similarly increased cellulase formation. Biolog Phenotype MicroArray analysis identified lack of N-acetyl-beta-D-mannosamine utilization as a specific trait of strains with the chitinase-overproducing haplotype. This observation was used to develop a plate screening assay for rapid microbiological identification of the strains. The data illustrate that desired industrial properties may be an attribute of certain populations within a species, and screening procedures should thus include a balanced mixture of all genotypes of a given species. PMID:17827332

  7. Microsatellite-based genotyping of Candida parapsilosis sensu stricto isolates reveals dominance and persistence of a particular epidemiological clone among neonatal intensive care unit patients.

    PubMed

    Romeo, Orazio; Delfino, Demetrio; Cascio, Antonio; Lo Passo, Carla; Amorini, Maria; Romeo, Daniela; Pernice, Ida

    2013-01-01

    In this study, using multilocus microsatellite analysis, we report the genetic characterization of 27 Candida parapsilosis isolates recovered in two different periods of time (2007-2009 and 2011-2012) from infants hospitalized in the neonatal intensive care unit of a hospital in Messina, Italy. The results revealed the persistence and dominance of a particular infectious genotype among NICU patients and highlight the power of the used microsatellite markers in clarifying epidemiologic associations, detect micro-evolutionary variations and facilitating the recognition of outbreaks. PMID:23022715

  8. Reappraisal of Hydatigera taeniaeformis (Batsch, 1786) (Cestoda: Taeniidae) sensu lato with description of Hydatigera kamiyai n. sp.

    PubMed

    Lavikainen, Antti; Iwaki, Takashi; Haukisalmi, Voitto; Konyaev, Sergey V; Casiraghi, Maurizio; Dokuchaev, Nikolai E; Galimberti, Andrea; Halajian, Ali; Henttonen, Heikki; Ichikawa-Seki, Madoka; Itagaki, Tadashi; Krivopalov, Anton V; Meri, Seppo; Morand, Serge; Näreaho, Anu; Olsson, Gert E; Ribas, Alexis; Terefe, Yitagele; Nakao, Minoru

    2016-05-01

    The common cat tapeworm Hydatigera taeniaeformis is a complex of three morphologically cryptic entities, which can be differentiated genetically. To clarify the biogeography and the host spectrum of the cryptic lineages, 150 specimens of H. taeniaeformis in various definitive and intermediate hosts from Eurasia, Africa and Australia were identified with DNA barcoding using partial mitochondrial cytochrome c oxidase subunit 1 gene sequences and compared with previously published data. Additional phylogenetic analyses of selected isolates were performed using nuclear DNA and mitochondrial genome sequences. Based on molecular data and morphological analysis, Hydatigera kamiyai n. sp. Iwaki is proposed for a cryptic lineage, which is predominantly northern Eurasian and uses mainly arvicoline rodents (voles) and mice of the genus Apodemus as intermediate hosts. Hydatigera taeniaeformis sensu stricto (s.s.) is restricted to murine rodents (rats and mice) as intermediate hosts. It probably originates from Asia but has spread worldwide. Despite remarkable genetic divergence between H. taeniaeformis s.s. and H. kamiyai, interspecific morphological differences are evident only in dimensions of rostellar hooks. The third cryptic lineage is closely related to H. kamiyai, but its taxonomic status remains unresolved due to limited morphological, molecular, biogeographical and ecological data. This Hydatigera sp. is confined to the Mediterranean and its intermediate hosts are unknown. Further studies are needed to classify Hydatigera sp. either as a distinct species or a variant of H. kamiyai. According to previously published limited data, all three entities occur in the Americas, probably due to human-mediated introductions. PMID:26956060

  9. Exposure to disinfectants (soap or hydrogen peroxide) increases tolerance to permethrin in Anopheles gambiae populations from the city of Yaoundé, Cameroon

    PubMed Central

    2014-01-01

    Background The rapid expansion of insecticide resistance is limiting the efficiency of malaria vector control interventions. However, current knowledge of factors inducing pyrethroid resistance remains incomplete. In the present study, the role of selection at the larval stage by disinfectants, such as soap and hydrogen peroxide (H2O2), on adult mosquito resistance to permethrin was investigated. Methods Field Anopheles gambiae sensu lato larvae, were exposed to variable concentrations of soap and H2O2. Larvae surviving to acute toxicity assays after 24 hours were reared to the adult stage and exposed to permethrin. The susceptibility level of adults was compared to the untreated control group. The effect of soap or hydrogen peroxide selection on the length of larval development and emergence rate was assessed. Result Larval bioassays analysis showed a more acute effect of hydrogen peroxide on mosquito larvae compared to soap. The regression lines describing the dose mortality profile showed higher mean and variance to hydrogen peroxide than to soap. The duration of larval development (<5 days) and adults emergence rates (1 to 77%) were shorter and lower compare to control. Anopheles gambiae s.l. larvae surviving to selection with either soap or hydrogen peroxide or both, produced adults who were up to eight-times more resistant to permethrin than mosquitoes from the untreated control group. Conclusion The present study shows that selective pressure exerted by non-insecticidal compounds such as soap and hydrogen peroxide affect An. gambiae s.l. tolerance to pyrethroids. This requires further studies with regard to the adaptation of An. gambiae s.l. to polluted habitats across sub-Saharan Africa cities. PMID:25086741

  10. Genetic Heterogeneity of Borrelia burgdorferi Sensu Lato in the Southern United States Based on Restriction Fragment Length Polymorphism and Sequence Analysis

    PubMed Central

    Lin, T.; Oliver, J. H.; Gao, L.; Kollars, T. M.; Clark, K. L.

    2001-01-01

    Fifty-six strains of Borrelia burgdorferi sensu lato, isolated from ticks and vertebrate animals in Missouri, South Carolina, Georgia, Florida, and Texas, were identified and characterized by PCR-restriction fragment length polymorphism (RFLP) analysis of rrf (5S)-rrl (23S) intergenic spacer amplicons. A total of 241 to 258 bp of intergenic spacers between tandemly duplicated rrf (5S) and rrl (23S) was amplified by PCR. MseI and DraI restriction fragment polymorphisms were used to analyze these strains. PCR-RFLP analysis results indicated that the strains represented at least three genospecies and 10 different restriction patterns. Most of the strains isolated from the tick Ixodes dentatus in Missouri and Georgia belonged to the genospecies Borrelia andersonii. Excluding the I. dentatus strains, most southern strains, isolated from the ticks Ixodes scapularis and Ixodes affinis, the cotton rat (Sigmodon hispidus), and cotton mouse (Peromyscus gossypinus) in Georgia and Florida, belonged to Borrelia burgdorferi sensu stricto. Seven strains, isolated from Ixodes minor, the wood rat (Neotoma floridana), the cotton rat, and the cotton mouse in South Carolina and Florida, belonged to Borrelia bissettii. Two strains, MI-8 from Florida and TXW-1 from Texas, exhibited MseI and DraI restriction patterns different from those of previously reported genospecies. Eight Missouri tick strains (MOK-3a group) had MseI patterns similar to that of B. andersonii reference strain 21038 but had a DraI restriction site in the spacer. Strain SCGT-8a had DraI restriction patterns identical to that of strain 25015 (B. bissettii) but differed from strain 25015 in its MseI restriction pattern. Strain AI-1 had the same DraI pattern as other southern strains in the B. bissettii genospecies but had a distinct MseI profile. The taxonomic status of these atypical strains needs to be further evaluated. To clarify the taxonomic positions of these atypical Borrelia strains, the complete sequences of

  11. Risk factors for house-entry by malaria vectors in a rural town and satellite villages in The Gambia

    PubMed Central

    Kirby, Matthew J; Green, Clare; Milligan, Paul M; Sismanidis, Charalambos; Jasseh, Momadou; Conway, David J; Lindsay, Steven W

    2008-01-01

    Background In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry. Methods Mosquitoes were sampled using CDC light traps in 976 houses, each on one night, in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia. Catches from individual houses were both (a) left unadjusted and (b) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period, to allow for night-to-night variation. Houses were characterized by location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. Results 106,536 mosquitoes were caught, of which 55% were Anopheles gambiae sensu lato, the major malaria vectors in the region. There were seven fold higher numbers of An. gambiae s.l. in the villages (geometric mean per trap night = 43.7, 95% confidence intervals, CIs = 39.5–48.4) than in Farafenni town (6.3, 5.7–7.2) and significant variation between residential blocks (p < 0.001). A negative binomial multivariate model performed equally well using unadjusted or adjusted trap data. Using the unadjusted data the presence of nuisance mosquitoes was reduced if the house was located in the town (odds ratio, OR = 0.11, 95% CIs = 0.09–0.13), the eaves were closed (OR = 0.71, 0.60–0.85), a horse was tethered near the house (OR = 0.77, 0.73–0.82), and churai, a local incense, was burned in the room at night (OR = 0.56, 0.47–0.66). Mosquito numbers increased per additional person in the house (OR = 1.04, 1.02–1.06) or trapping room (OR = 1.19, 1.13–1.25) and when the walls were made of mud blocks compared with concrete (OR = 1.44, 1.10–1.87). Conclusion This study demonstrates that the risk of

  12. Speciation history and widespread introgression in the European short-call tree frogs (Hyla arborea sensu lato, H. intermedia and H. sarda).

    PubMed

    Gvoždík, Václav; Canestrelli, Daniele; García-París, Mario; Moravec, Jiří; Nascetti, Giuseppe; Recuero, Ernesto; Teixeira, José; Kotlík, Petr

    2015-02-01

    European tree frogs (Hyla) characterized by short temporal parameters of the advertisement call form six genetically differentiated but morphologically cryptic taxa, H. arborea sensu stricto, H. orientalis and H. molleri from across Europe to western Asia (together referred to as H. arborea sensu lato), two putative taxa within H. intermedia (Northern and Southern) from the Italian Peninsula and Sicily, and H. sarda from Sardinia and Corsica. Here, we assess species limits and phylogenetic relationships within these 'short-call tree frogs' based on mitochondrial DNA and nuclear protein-coding markers. The mitochondrial and nuclear genes show partly incongruent phylogeographic patterns, which point to a complex history of gene flow across taxa, particularly in the Balkans. To test the species limits in the short-call tree frogs and to infer the species tree, we used coalescent-based approaches. The monophyly of H. arborea sensu lato is supported by the mtDNA as well as by the all-gene species tree. The Northern and Southern lineages of H. intermedia have been connected by nuclear gene flow (despite their deep mtDNA divergence) and should be treated as conspecific. On the contrary, the parapatric taxa within H. arborea sensu lato should be considered distinct species (H. arborea, H. orientalis, H. molleri) based on the coalescent analysis, although signs of hybridization were detected between them (H. arborea×H. orientalis; H. arborea×H. molleri). A mitochondrial capture upon secondary contact appears to explain the close mtDNA relationship between the geographically remote Iberian H. molleri and H. orientalis from around the Black Sea. Introgressive hybridization occurred also between the Balkan H. arborea and northern Italian H. intermedia, and between the Minor Asiatic H. orientalis and Arabian H. felix arabica (the latter belonging to a different acoustic group/clade). Our results shed light on the species limits in the European short-call tree frogs and show

  13. CLIP proteases and Plasmodium melanization in Anopheles gambiae.

    PubMed

    Barillas-Mury, Carolina

    2007-07-01

    Melanization is a potent immune response mediated by phenoloxidase (PO). Multiple Clip-domain serine proteases (CLIP) regulate PO activation as part of a complex cascade of proteases that are cleaved sequentially. The role of several CLIP as key activators or suppressors of the melanization responses of Anopheles gambiae to Plasmodium berghei (murine malaria) has been established recently using a genome-wide reverse genetics approach. Important differences in regulation of PO activation between An. gambiae strains were also identified. This review summarizes these findings and discusses our current understanding of the An. gambiae melanization responses to Plasmodium. PMID:17512801

  14. The problem of exophily in Anopheles gambiae

    PubMed Central

    Gillies, M. T.

    1956-01-01

    Studies of the exophily exhibited by anophelines in a humid coastal area and in an arid inland region of Tanganyika gave very different results. In the former area, catches of A. gambiae were scanty and largely composed of unfed and gravid females, while in the latter, large numbers of mosquitos were caught outside and a great many of them were recently fed females. The differences are attributed primarily to the presence outside of large herds of cattle in the inland region and to their absence near the coast. The reports of exophily from other parts of Africa are also analysed and show that there is much variation in the behaviour of A. gambiae in different regions. Some of the variation can be explained in terms of environmental differences, particularly in the availability at night of different hosts. But some of it may be genetically determined. It is suggested that the main task in this field is twofold: firstly, to establish the existence and nature of the behaviour differences described; secondly, to study in detail the mosquitos that survive as exophilic populations in areas where systematic house-spraying is in operation. PMID:13404431

  15. Anthrax in the Gambia: an epidemiological study

    PubMed Central

    Heyworth, B; Ropp, M E; Voos, U G; Meinel, H I; Darlow, H M

    1975-01-01

    Epidemiological data on 448 cases of human cutaneous anthrax from the Gambia showed that this particular strain of anthrax bacillus causes widespread morbidity and some mortality with, at the same time, subclinical infection. Analysis also showed that anthrax is not an occupationally related disease in the Gambia. The possibility of human-to-human spread, affecting all age groups and both sexes, by means of a communal toilet article was also shown. The fact that the strain is a good toxin producer but contains a weak antigen may have accounted for the repeated clinical infection and the fact that antibody titres were generally transient. Subclinical infection in animals was also found, particularly in sheep and goats, and also, with an unusually low mortality, in cows. Insect vectors were not excluded, but were unlikely. Vultures may spread the disease from village to village. Some possible public health and immunization procedures are discussed, with a view to containing this difficult problem in this part of west Africa. PMID:810213

  16. Odourant reception in the malaria mosquito Anopheles gambiae

    PubMed Central

    Carey, Allison; Wang, Guirong; Su, Chih-Ying; Zwiebel, Laurence J.; Carlson, John R.

    2010-01-01

    Summary The mosquito Anopheles gambiae is the major vector of malaria in sub-Saharan Africa. It locates its human hosts primarily through olfaction, but little is known about the molecular basis of this process. Here we functionally characterize the Anopheles gambiae Odourant Receptor (AgOr) repertoire. We identify receptors that respond strongly to components of human odour and that may act in the process of human recognition. Some of these receptors are narrowly tuned, and some salient odourants elicit strong responses from only one or a few receptors, suggesting a central role for specific transmission channels in human host-seeking behavior. This analysis of the Anopheles gambiae receptors permits a comparison with the corresponding Drosophila melanogaster odourant receptor repertoire. We find that odourants are differentially encoded by the two species in ways consistent with their ecological needs. Our analysis of the Anopheles gambiae repertoire identifies receptors that may be useful targets for controlling the transmission of malaria. PMID:20130575

  17. Quantitative Detection of Borrelia burgdorferi sensu lato in Erythema Migrans Skin Lesions Using Internally Controlled Duplex Real Time PCR

    PubMed Central

    Lusa, Lara; Stupica, Dasa; Maraspin, Vera; Barrett, P. Noel; Strle, Franc; Livey, Ian

    2013-01-01

    B. burgdorferi sensu stricto, B. afzelii, B. garinii and B. bavariensis are the principal species which account for Lyme borreliosis (LB) globally. We have developed an internally controlled duplex quantitative real time PCR assay targeting the Borrelia 16S rRNA and the human RNAseP genes. This assay is well-suited for laboratory confirmation of suspected cases of LB and will be used to assess the efficacy of a vaccine against LB in clinical trials. The assay is highly specific, successfully detecting DNA extracted from 83 diverse B. burgdorferi sensu lato strains representing all major species causing LB, while 21 unrelated microbial species and human genomic DNA tested negative. The assay was highly reproducible and sensitive, with a lower limit of detection of 6 copies per PCR reaction. Together with culture, the assay was used to evaluate paired 3 mm skin biopsy samples taken from 121 patients presenting with solitary erythema migrans (EM) lesion. PCR testing identified more positive biopsy samples than culture (77.7% PCR positive versus 55.1% culture positive) and correctly identified all specimens scored as culture positive. OspA-based typing identified the majority of isolates as B. afzelii (96.8%) and the bacterial load was significantly higher in culture positive biopsies than in culture negative biopsies (P<0.001). The quantitative data also enabled relationships between Borrelia burden and patient symptoms to be evaluated. The bacterial load was significantly higher among patients with systemic symptoms than without (P = 0.02) and was significantly higher for biopsies retrieved from patients with EM lesions with central clearing (P<0.001). 16S copy numbers were moderately lower in samples from patients reporting a history of LB (P = 0.10). This is the first quantitative PCR study of human skin biopsies predominantly infected with B. afzelii and the first study to demonstrate a clear relationship between clinical symptoms in B. afzelii

  18. Manipulating Steady Heat Conduction by Sensu-shaped Thermal Metamaterials

    PubMed Central

    Han, Tiancheng; Bai, Xue; Liu, Dan; Gao, Dongliang; Li, Baowen; Thong, John T. L.; Qiu, Cheng-Wei

    2015-01-01

    The ability to design the control of heat flow has innumerable benefits in the design of electronic systems such as thermoelectric energy harvesters, solid-state lighting, and thermal imagers, where the thermal design plays a key role in performance and device reliability. In this work, we employ one identical sensu-unit with facile natural composition to experimentally realize a new class of thermal metamaterials for controlling thermal conduction (e.g., thermal concentrator, focusing/resolving, uniform heating), only resorting to positioning and locating the same unit element of sensu-shape structure. The thermal metamaterial unit and the proper arrangement of multiple identical units are capable of transferring, redistributing and managing thermal energy in a versatile fashion. It is also shown that our sensu-shape unit elements can be used in manipulating dc currents without any change in the layout for the thermal counterpart. These could markedly enhance the capabilities in thermal sensing, thermal imaging, thermal-energy storage, thermal packaging, thermal therapy, and more domains beyond. PMID:25974383

  19. ITS1, 5.8S and ITS2 secondary structure modelling for intra-specific differentiation among species of the Colletotrichum gloeosporioides sensu lato species complex.

    PubMed

    Rampersad, Sephra N

    2014-01-01

    The Colletotrichum gloeosporioides species complex is among the most destructive fungal plant pathogens in the world, however, identification of member species which are of quarantine importance is impacted by a number of factors that negatively affect species identification. Structural information of the rRNA marker may be considered to be a conserved marker which can be used as supplementary information for possible species identification. The difficulty in using ITS rDNA sequences for identification lies in the low level of sequence variation at the intra-specific level and the generation of artificially-induced sequence variation due to errors in polymerization of the ITS array during DNA replication. Type and query ITS sequences were subjected to sequence analyses prior to generation of predicted consensus secondary structures, including the pattern of nucleotide polymorphisms and number of indel haplotypes, GC content, and detection of artificially-induced sequence variation. Data pertaining to structure stability, the presence of conserved motifs in secondary structures and mapping of all sequences onto the consensus C. gloeosporioides sensu stricto secondary structure for ITS1, 5.8S and ITS2 markers was then carried out. Motifs that are evolutionarily conserved among eukaryotes were found for all ITS1, 5.8S and ITS2 sequences. The sequences exhibited conserved features typical of functional rRNAs. Generally, polymorphisms occurred within less conserved regions and were seen as bulges, internal and terminal loops or non-canonical G-U base-pairs within regions of the double stranded helices. Importantly, there were also taxonomic motifs and base changes that were unique to specific taxa and which may be used to support intra-specific identification of members of the C. gloeosporioides sensu lato species complex. PMID:25512885

  20. Combining Technical Competence and Stakeholder Impact in Environmental Education: The Gambia All Schools Nursery Competition

    ERIC Educational Resources Information Center

    Paulete, Francisca E.; Orr, Blair

    2010-01-01

    Under the guidance of the Department of Forestry, the Regional Education Directorate, and Peace Corps/The Gambia, the Gambia All Schools Tree Nursery Competition, an environmental education program, was developed to introduce practical environmental education in The Gambia. Data for this report were collected using a rapid appraisal approach.…

  1. RNAi Trigger Delivery into Anopheles gambiae Pupae

    PubMed Central

    Regna, Kimberly; Harrison, Rachel M.; Heyse, Shannon A.; Chiles, Thomas C.; Michel, Kristin; Muskavitch, Marc A. T.

    2016-01-01

    RNA interference (RNAi), a naturally occurring phenomenon in eukaryotic organisms, is an extremely valuable tool that can be utilized in the laboratory for functional genomic studies. The ability to knockdown individual genes selectively via this reverse genetic technique has allowed many researchers to rapidly uncover the biological roles of numerous genes within many organisms, by evaluation of loss-of-function phenotypes. In the major human malaria vector Anopheles gambiae, the predominant method used to reduce the function of targeted genes involves injection of double-stranded (dsRNA) into the hemocoel of the adult mosquito. While this method has been successful, gene knockdown in adults excludes the functional assessment of genes that are expressed and potentially play roles during pre-adult stages, as well as genes that are expressed in limited numbers of cells in adult mosquitoes. We describe a method for the injection of Serine Protease Inhibitor 2 (SRPN2) dsRNA during the early pupal stage and validate SRPN2 protein knockdown by observing decreased target protein levels and the formation of melanotic pseudo-tumors in SRPN2 knockdown adult mosquitoes. This evident phenotype has been described previously for adult stage knockdown of SRPN2 function, and we have recapitulated this adult phenotype by SRPN2 knockdown initiated during pupal development. When used in conjunction with a dye-labeled dsRNA solution, this technique enables easy visualization by simple light microscopy of injection quality and distribution of dsRNA in the hemocoel. PMID:27023367

  2. Behavioral cost & overdominance in Anopheles gambiae.

    PubMed

    Diop, Malal M; Moiroux, Nicolas; Chandre, Fabrice; Martin-Herrou, Hadrien; Milesi, Pascal; Boussari, Olayidé; Porciani, Angélique; Duchon, Stéphane; Labbé, Pierrick; Pennetier, Cédric

    2015-01-01

    In response to the widespread use of control strategies such as Insecticide Treated Nets (ITN), Anopheles mosquitoes have evolved various resistance mechanisms. Kdr is a mutation that provides physiological resistance to the pyrethroid insecticides family (PYR). In the present study, we investigated the effect of the Kdr mutation on the ability of female An. gambiae to locate and penetrate a 1cm-diameter hole in a piece of netting, either treated with insecticide or untreated, to reach a bait in a wind tunnel. Kdr homozygous, PYR-resistant mosquitoes were the least efficient at penetrating an untreated damaged net, with about 51% [39-63] success rate compared to 80% [70-90] and 78% [65-91] for homozygous susceptible and heterozygous respectively. This reduced efficiency, likely due to reduced host-seeking activity, as revealed by mosquito video-tracking, is evidence of a recessive behavioral cost of the mutation. Kdr heterozygous mosquitoes were the most efficient at penetrating nets treated with PYR insecticide, thus providing evidence for overdominance, the rarely-described case of heterozygote advantage conveyed by a single locus. The study also highlights the remarkable capacity of female mosquitoes, whether PYR-resistant or not, to locate holes in bed-nets. PMID:25831058

  3. Anopheles gambiae, a complex of species

    PubMed Central

    Davidson, G.

    1964-01-01

    The author reports on some 200 laboratory crossings of 36 strains of Anopheles gambiae from many different parts of Africa which show the existence of five mating-types in what was until recently considered a single species. Three of these mating-types are freshwater forms and have been provisionally called A, B and C. Two are saltwater forms: A. melas, confined to West Africa, and the East African A. merus. Hybrid male sterility is universal when any two of these five forms are crossed, and from some of the crosses grossly abnormal sex-ratios result. From an evolutionary standpoint these five mating-types are probably species or semi-species in view of the fact that they can be found to co-exist sympatrically and still retain their identities. From a practical point of view it may be necessary for the field worker to be able to identify the exact species with which he is dealing before the most efficient means of controlling it can be found. ImagesFIG. 1FIG. 2FIG. 3 PMID:14278001

  4. Behavioral Cost & Overdominance in Anopheles gambiae

    PubMed Central

    Diop, Malal M.; Moiroux, Nicolas; Chandre, Fabrice; Martin-Herrou, Hadrien; Milesi, Pascal; Boussari, Olayidé; Porciani, Angélique; Duchon, Stéphane; Labbé, Pierrick; Pennetier, Cédric

    2015-01-01

    In response to the widespread use of control strategies such as Insecticide Treated Nets (ITN), Anopheles mosquitoes have evolved various resistance mechanisms. Kdr is a mutation that provides physiological resistance to the pyrethroid insecticides family (PYR). In the present study, we investigated the effect of the Kdr mutation on the ability of female An. gambiae to locate and penetrate a 1cm-diameter hole in a piece of netting, either treated with insecticide or untreated, to reach a bait in a wind tunnel. Kdr homozygous, PYR-resistant mosquitoes were the least efficient at penetrating an untreated damaged net, with about 51% [39-63] success rate compared to 80% [70-90] and 78% [65-91] for homozygous susceptible and heterozygous respectively. This reduced efficiency, likely due to reduced host-seeking activity, as revealed by mosquito video-tracking, is evidence of a recessive behavioral cost of the mutation. Kdr heterozygous mosquitoes were the most efficient at penetrating nets treated with PYR insecticide, thus providing evidence for overdominance, the rarely-described case of heterozygote advantage conveyed by a single locus. The study also highlights the remarkable capacity of female mosquitoes, whether PYR-resistant or not, to locate holes in bed-nets. PMID:25831058

  5. Girls' Familial Responsibilities and Schooling in The Gambia

    ERIC Educational Resources Information Center

    Njie, Haddy; Manion, Caroline; Badjie, Musukuta

    2015-01-01

    Like many countries in the developing world gender inequity remains a staggering problem in The Gambia, particularly at the secondary school level. In this study, we focus on the relationship between girls' education and heavy domestic workloads, herein referred to as girls' familial responsibilities. We explore this topic in relation not only to…

  6. Science Education in the Gambia--UK Students' Perspectives

    ERIC Educational Resources Information Center

    Vatcher, Judy

    2009-01-01

    In this article, the author shares UK students' experience in a ten-day trip to the Gambia. During the trip, three schools were visited and students taught their lessons in pairs, each pair delivering two 20-minute lessons. Topics covered were chosen beforehand to relate to the Gambian curriculum and the equipment used was selected on a local…

  7. Infertility in the Gambia: Traditional and Modern Health Care.

    ERIC Educational Resources Information Center

    Sundby, Johanne

    1997-01-01

    A population survey was undertaken to study infertility in Gambia. All infertile women in 24 randomly selected enumeration areas were assessed. Problems faced, coping mechanisms employed, and types of health care available were examined. Patterns of consultation with traditional versus formal health care and rural/urban differences were uncovered…

  8. Urban Senegal and Rural Gambia: Computer and Community Education Programs.

    ERIC Educational Resources Information Center

    Pagano, Alicia I.

    1986-01-01

    Describes two educational programs in West Africa: a (LOGO) computer education program in Senegal, and a "self-improvement" community education program in The Gambia. While these two programs are diverse in geographic location, population, and curriculum materials, both are action-oriented, learner controlled, and consider the learner's broader…

  9. The dance of male Anopheles gambiae in mating swarms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mating behavior of the malaria vector Anopheles gambiae is of great interest from a fundamental and applied perspective. One of the most important elements of mating in this species is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and inseminat...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Molecular epidemiology of Haemophilus influenzae type b in the Gambia.

    PubMed Central

    Bijlmer, H A; van Alphen, L; Geelen-van den Broek, L; Greenwood, B M; Valkenburg, H A; Dankert, J

    1992-01-01

    One hundred two invasive and 64 noninvasive isolates of Haemophilus influenzae were collected in the course of a 2-year prospective field study on the epidemiology of H. influenzae meningitis in The Gambia. The isolates were serotyped, biotyped, and subtyped by outer membrane protein (OMP) profile analysis (OMP subtyping). H. influenzae meningitis was found to be caused by serotype b (95%). In invasive disease, serotype a, although present in the throat of healthy children, caused only occasionally (5.9%) disease. The distribution of biotypes of H. influenzae appeared to be very similar to that found outside The Gambia. A distinct pattern of OMP subtypes, different from other parts of the world, is prevalent in H. influenzae type b (Hib) in The Gambia. OMP subtypes 2, 4, 5, 8, and 9 were observed to be predominant. These subtypes, except subtype 2, have not been described. L subtypes (subtypes 2, 4, and 8) were associated with invasive disease, whereas non-L subtypes (subtypes 5 and 9) were found more often in healthy carriers (P less than 0.001). A significant difference in geographical distribution was found in subtypes of noninvasive Hib strains (P less than 0.05). We conclude that in The Gambia H. influenzae invasive disease is caused mainly by type b strains with a limited number of OMP subtypes, which are different from the subtypes found elsewhere in the world. These data are important for the surveillance of Hib disease in developing countries and are baseline data for a Hib polyribosyl-ribitolphosphate-conjugated vaccine trial in The Gambia. Alternative Hib OMP vaccines should include a set of representative OMPs. Images PMID:1537907

  12. Seasonality of Ixodes ricinus Ticks on Vegetation and on Rodents and Borrelia burgdorferi sensu lato Genospecies Diversity in Two Lyme Borreliosis–Endemic Areas in Switzerland

    PubMed Central

    Pérez, David; Kneubühler, Yvan; Rais, Olivier

    2012-01-01

    Abstract We compared Ixodes ricinus questing density, the infestation of rodents by immature stages, and the diversity of Borrelia burgdorferi sensu lato (sl) in questing ticks and ticks collected from rodents in two Lyme borreliosis (LB)-endemic areas in Switzerland (Portes-Rouges [PR] and Staatswald [SW]) from 2003 to 2005. There were variations in the seasonal pattern of questing tick densities among years. Questing nymphs were globally more abundant at PR than at SW, but the proportion of rodents infested by immature ticks was similar (59.4% and 61%, respectively). Questing tick activity lasted from February to November with a strong decline in June. The seasonal pattern of ticks infesting rodents was different. Ticks infested rodents without decline in summer, suggesting that the risk of being bitten by ticks remains high during the summer. Rodents from SW showed the highest infestation levels (10±21.6 for larvae and 0.54±1.65 for nymphs). The proportion of rodents infested simultaneously by larvae and nymphs (co-feeding ticks) was higher at SW (28%) than at PR (11%). Apodemus flavicollis was the species the most frequently infested by co-feeding ticks, and Myodes glareolus was the most infective rodent species as measured by xenodiagnosis. At PR, the prevalence of B. burgdorferi sl in questing ticks was higher (17.8% for nymphs and 32.4% for adults) than at SW (10.4% for nymphs and 24.8% for adults), with B. afzelii as the dominant species, but B. garinii, B. burgdorferi sensu stricto, and B. valaisiana were also detected. Rodents transmitted only B. afzelii (at PR and at SW) and B. bavariensis (at SW) to ticks, and no mixed infection by additional genospecies was observed in co-feeding ticks. This implies that co-feeding transmission does not contribute to genospecies diversity. However, persistent infections in rodents and co-feeding transmission contribute to the perpetuation of B. afzelii in nature. PMID:22607074

  13. Spatial distribution and male mating success of Anopheles gambiae swarms

    PubMed Central

    2011-01-01

    Background Anopheles gambiae mates in flight at particular mating sites over specific landmarks known as swarm markers. The swarms are composed of males; females typically approach a swarm, and leave in copula. This mating aggregation looks like a lek, but appears to lack the component of female choice. To investigate the possible mechanisms promoting the evolution of swarming in this mosquito species, we looked at the variation in mating success between swarms and discussed the factors that structure it in light of the three major lekking models, known as the female preference model, the hotspot model, and the hotshot model. Results We found substantial variation in swarm size and in mating success between swarms. A strong correlation between swarm size and mating success was observed, and consistent with the hotspot model of lek formation, the per capita mating success of individual males did not increase with swarm size. For the spatial distribution of swarms, our results revealed that some display sites were more attractive to both males and females and that females were more attracted to large swarms. While the swarm markers we recognize help us in localizing swarms, they did not account for the variation in swarm size or in the swarm mating success, suggesting that mosquitoes probably are attracted to these markers, but also perceive and respond to other aspects of the swarming site. Conclusions Characterizing the mating system of a species helps understand how this species has evolved and how selective pressures operate on male and female traits. The current study looked at male mating success of An. gambiae and discussed possible factors that account for its variation. We found that swarms of An. gambiae conform to the hotspot model of lek formation. But because swarms may lack the female choice component, we propose that the An. gambiae mating system is a lek-like system that incorporates characteristics pertaining to other mating systems such as scramble

  14. Coxiella burnetii Seroprevalence in Small Ruminants in The Gambia

    PubMed Central

    Klaasen, Marieke; Roest, Hendrik-Jan; van der Hoek, Wim; Goossens, Bart; Secka, Arss; Stegeman, Arjan

    2014-01-01

    Background Q fever is a zoonosis caused by Coxiella burnetii, a Gram negative bacterium present worldwide. Small ruminants are considered the main reservoirs for infection of humans. This study aimed to estimate the extent of C. burnetii infection among sheep and goats in part of The Gambia. Methodology/Principal Findings This survey was carried out from March to May 2012 at two areas in The Gambia. The first area comprised a cluster of seven rural villages situated 5–15 km west of Farafenni as well as the local abattoir. A second sampling was done at the central abattoir in Abuko (30 km from the capital, Banjul) in the Western Region. Serum samples were obtained from 490 goats and 398 sheep. In addition, 67 milk samples were obtained from lactating dams. Sera were tested with a Q fever ELISA kit. C. burnetii DNA was extracted from milk samples and then detected using a specific quantitative multiplex PCR assay, targeting the IS1111a element. A multivariable mixed logistic regression model was used to examine the relationship between seropositivity and explanatory variables. An overall seroprevalence of 21.6% was found. Goats had a significantly higher seroprevalence than sheep, respectively 24.2% and 18.5%. Seropositive animals were significantly older than seronegative animals. Animals from the villages had a significantly lower seroprevalence than animals from the central abattoir (15.1% versus 29.1%). C. burnetii DNA was detected in 2 out of 67 milk samples, whereas 8 samples gave a doubtful result. Conclusion/Significance A substantial C. burnetii seroprevalence in sheep and goats in The Gambia was demonstrated. People living in close proximity to small ruminants are exposed to C. burnetii. Q fever should be considered as a possible cause of acute febrile illness in humans in The Gambia. Future studies should include a simultaneous assessment of veterinary and human serology, and include aetiology of febrile illness in local clinics. PMID:24454863

  15. A proposal for the classification of biological weapons sensu lato.

    PubMed

    Rozsa, Lajos

    2014-12-01

    Due to historical and legislation reasons, the category of bioweapons is rather poorly defined. Authors often disagree on involving or excluding agents like hormones, psychochemicals, certain plants and animals (such as weeds or pests) or synthetic organisms. Applying a wide definition apparently threatens by eroding the regime of international legislation, while narrow definitions abandon several important issues. Therefore, I propose a category of 'biological weapons sensu lato' (BWsl) that is defined here as any tool of human aggression whose acting principle is based on disciplines of biology including particularly microbiology, epidemiology, medical biology, physiology, psychology, pharmacology and ecology, but excluding those based on inorganic agents. Synthetically produced equivalents (not necessarily exact copies) and mock weapons are also included. This definition does not involve any claim to subject all these weapons to international legislation but serves a purely scholarly purpose. BWsl may be properly categorized on the base of the magnitude of the human population potentially targeted (4 levels: individuals, towns, countries, global) and the biological nature of the weapons' intended effects (4 levels: agricultural-ecological agents, and non-pathogenic, pathogenic, or lethal agents against humans). PMID:24992886

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. In vitro and in vivo host range of Anopheles gambiae densovirus (AgDNV)

    PubMed Central

    Suzuki, Yasutsugu; Barik, Tapan K.; Johnson, Rebecca M.; Rasgon, Jason L.

    2015-01-01

    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. PMID:26220140

  18. Evolution of GOUNDRY, a cryptic subgroup of Anopheles gambiae s.l., and its impact on susceptibility to Plasmodium infection.

    PubMed

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

    2016-04-01

    The recent discovery of a previously unknown genetic subgroup of Anopheles gambiae sensu lato underscores our incomplete understanding of complexities of vector population demographics in Anopheles. This subgroup, named GOUNDRY, does not rest indoors as adults and is highly susceptible to Plasmodium infection in the laboratory. Initial description of GOUNDRY suggested it differed from other known Anopheles taxa in surprising and sometimes contradictory ways, raising a number of questions about its age, population size and relationship to known subgroups. To address these questions, we sequenced the complete genomes of 12 wild-caught GOUNDRY specimens and compared these genomes to a panel of Anopheles genomes. We show that GOUNDRY is most closely related to Anopheles coluzzii, and the timing of cladogenesis is not recent, substantially predating the advent of agriculture. We find a large region of the X chromosome that has swept to fixation in GOUNDRY within the last 100 years, which may be an inversion that serves as a partial barrier to contemporary gene flow. Interestingly, we show that GOUNDRY has a history of inbreeding that is significantly associated with susceptibility to Plasmodium infection in the laboratory. Our results illuminate the genomic evolution of one of probably several cryptic, ecologically specialized subgroups of Anopheles and provide a potent example of how vector population dynamics may complicate efforts to control or eradicate malaria. PMID:26846876

  19. G Protein-Coupled Receptors in Anopheles gambiae

    NASA Astrophysics Data System (ADS)

    Hill, Catherine A.; Fox, A. Nicole; Pitts, R. Jason; Kent, Lauren B.; Tan, Perciliz L.; Chrystal, Mathew A.; Cravchik, Anibal; Collins, Frank H.; Robertson, Hugh M.; Zwiebel, Laurence J.

    2002-10-01

    We used bioinformatic approaches to identify a total of 276 G protein-coupled receptors (GPCRs) from the Anopheles gambiae genome. These include GPCRs that are likely to play roles in pathways affecting almost every aspect of the mosquito's life cycle. Seventy-nine candidate odorant receptors were characterized for tissue expression and, along with 76 putative gustatory receptors, for their molecular evolution relative to Drosophila melanogaster. Examples of lineage-specific gene expansions were observed as well as a single instance of unusually high sequence conservation.

  20. Immunity-related genes and gene families in Anopheles gambiae.

    PubMed

    Christophides, George K; Zdobnov, Evgeny; Barillas-Mury, Carolina; Birney, Ewan; Blandin, Stephanie; Blass, Claudia; Brey, Paul T; Collins, Frank H; Danielli, Alberto; Dimopoulos, George; Hetru, Charles; Hoa, Ngo T; Hoffmann, Jules A; Kanzok, Stefan M; Letunic, Ivica; Levashina, Elena A; Loukeris, Thanasis G; Lycett, Gareth; Meister, Stephan; Michel, Kristin; Moita, Luis F; Müller, Hans-Michael; Osta, Mike A; Paskewitz, Susan M; Reichhart, Jean-Marc; Rzhetsky, Andrey; Troxler, Laurent; Vernick, Kenneth D; Vlachou, Dina; Volz, Jennifer; von Mering, Christian; Xu, Jiannong; Zheng, Liangbiao; Bork, Peer; Kafatos, Fotis C

    2002-10-01

    We have identified 242 Anopheles gambiae genes from 18 gene families implicated in innate immunity and have detected marked diversification relative to Drosophila melanogaster. Immune-related gene families involved in recognition, signal modulation, and effector systems show a marked deficit of orthologs and excessive gene expansions, possibly reflecting selection pressures from different pathogens encountered in these insects' very different life-styles. In contrast, the multifunctional Toll signal transduction pathway is substantially conserved, presumably because of counterselection for developmental stability. Representative expression profiles confirm that sequence diversification is accompanied by specific responses to different immune challenges. Alternative RNA splicing may also contribute to expansion of the immune repertoire. PMID:12364793

  1. Trypanosome infections in warthogs (Phacochoerus aethiopicus) in the Gambia.

    PubMed

    Claxton, J R; Faye, J A; Rawlings, P

    1992-03-01

    The prevalence of trypanosome infections in warthogs (Phacochoerus aethiopicus) in The Gambia was found to be 11% of a sample of 62 animals. All isolates were identified as Trypanosoma simiae. Serological evidence indicated a higher level of exposure to T. simiae, but results were inconclusive for the presence of Trypanosoma congolense. The course of T. simiae infection in warthog piglets showed a rapidly rising parasitaemia, with a concomitant fall in packed cell volume, and resulted in a prolonged period of low-level parasitaemia. The same infections killed domestic piglets. PMID:1502780

  2. Constructing a Genome-Wide LD Map of Wild A. gambiae Using Next-Generation Sequencing

    PubMed Central

    Wang, Xiaohong; Afrane, Yaw A.; Yan, Guiyun; Li, Jun

    2015-01-01

    Anopheles gambiae is the major malaria vector in Africa. Examining the molecular basis of A. gambiae traits requires knowledge of both genetic variation and genome-wide linkage disequilibrium (LD) map of wild A. gambiae populations from malaria-endemic areas. We sequenced the genomes of nine wild A. gambiae mosquitoes individually using next-generation sequencing technologies and detected 2,219,815 common single nucleotide polymorphisms (SNPs), 88% of which are novel. SNPs are not evenly distributed across A. gambiae chromosomes. The low SNP-frequency regions overlay heterochromatin and chromosome inversion domains, consistent with the lower recombinant rates at these regions. Nearly one million SNPs that were genotyped correctly in all individual mosquitoes with 99.6% confidence were extracted from these high-throughput sequencing data. Based on these SNP genotypes, we constructed a genome-wide LD map for wild A. gambiae from malaria-endemic areas in Kenya and made it available through a public Website. The average size of LD blocks is less than 40 bp, and several large LD blocks were also discovered clustered around the para gene, which is consistent with the effect of insecticide selective sweeps. The SNPs and the LD map will be valuable resources for scientific communities to dissect the A. gambiae genome. PMID:26421280

  3. Infection of Ixodes ricinus (Acari: Ixodidae) by Borrelia burgdorferi sensu lato in North Africa

    USGS Publications Warehouse

    Zhioua, E.; Bouattour, A.; Hu, C.M.; Gharbi, M.; Aeschliman, A.; Ginsberg, H.S.; Gern, L.

    1999-01-01

    Free-living adult Ixodes ricinus L. were collected in Amdoun, situated in the Kroumiry mountains in northwestern Tunisia (North Africa). Using direct fluorescence antibody assay, the infection rate of field-collected I. ricinus by Borrelia burgdorferi sensu lato was 30.5% (n = 72). No difference in infection rate was observed between male and female ticks. Spirochetes that had been isolated from I. ricinus from Ain Drahim (Kroumiry Mountains) in 1988 were identified as Borrelia lusitaniae (formerly genospecies PotiB2). This is the first identification of a genospecies of Borrelia burgdorferi sensu lato from the continent of Africa.

  4. 'Who's who' in renal sphaerosporids (Bivalvulida: Myxozoa) from common carp, Prussian carp and goldfish--molecular identification of cryptic species, blood stages and new members of Sphaerospora sensu stricto.

    PubMed

    Holzer, Astrid Sibylle; Bartošová, P; Pecková, H; Tyml, T; Atkinson, S; Bartholomew, J; Sipos, D; Eszterbauer, E; Dyková, I

    2013-01-01

    Myxozoans are a group of diverse, spore-forming metazoan microparasites bound to aquatic environments. Sphaerospora dykovae (previously S. renicola) causes renal sphaerosporosis and acute swim bladder inflammation (SBI) in juvenile Cyprinus carpio carpio, in central Europe. A morphologically similar species with comparably low pathogenicity, S. angulata has been described from C. c. carpio, Carassius auratus auratus and Carassius gibelio. To clarify uncertainties and ambiguities in taxon identification in these hosts we decided to re-investigate differences in spore morphology using a statistical approach, in combination with SSU and LSU rDNA sequence analyses. We found that developing spores of S. angulata and S. dykovae cannot be distinguished morphologically and designed a duplex PCR assay for the cryptic species that demonstrated S. dykovae is specific to C. c. carpio, whereas S. angulata infects C. a. auratus and C. gibelio. The molecular identification of myxozoan blood stages in common carp and goldfish, which had previously been ascribed to Sphaerospora spp. showed that approximately 75% of blood stages were from non-sphaerosporid coelozoic species infecting these cyprinids and more than 10% were from an alien species, Myxobilatus gasterostei, developing in sticklebacks. We hereby report non-selective myxozoan host invasion and multi-species infections, whose role in SBI still requires clarification. PMID:22917178

  5. First report of the kdr mutation in Anopheles gambiae M form from Burkina Faso, west Africa.

    PubMed

    Diabaté, A; Baldet, T; Chandre, F; Guiguemdé, R T; Brengues, C; Guillet, P; Hemingway, J; Hougard, J M

    2002-12-01

    The kdr mutation, conferring resistance to pyrethroid insecticides, has been reported in several West-African populations of Anopheles gambiae S form and in the M form populations from tropical forest of Benin. We report the finding of a single M specimen collected in the rice-field area of Vallée du Kou (Burkina Faso) showing the mutation at the heterozygous state. The monitoring of kdr mutation in An. gambiae forms/species is of paramount importance to implement effective malaria control tools and may greatly improve the knowledge of the relationship between and within An. gambiae populations. PMID:12701378

  6. Gene expression-based biomarkers for Anopheles gambiae age grading.

    PubMed

    Wang, Mei-Hui; Marinotti, Osvaldo; Zhong, Daibin; James, Anthony A; Walker, Edward; Guda, Tom; Kweka, Eliningaya J; Githure, John; Yan, Guiyun

    2013-01-01

    Information on population age structure of mosquitoes under natural conditions is fundamental to the understanding of vectorial capacity and crucial for assessing the impact of vector control measures on malaria transmission. Transcriptional profiling has been proposed as a method for predicting mosquito age for Aedes and Anopheles mosquitoes, however, whether this new method is adequate for natural conditions is unknown. This study tests the applicability of transcriptional profiling for age-grading of Anopheles gambiae, the most important malaria vector in Africa. The transcript abundance of two An. gambiae genes, AGAP009551 and AGAP011615, was measured during aging under laboratory and field conditions in three mosquito strains. Age-dependent monotonic changes in transcript levels were observed in all strains evaluated. These genes were validated as age-grading biomarkers using the mark, release and recapture (MRR) method. The MRR method determined a good correspondence between actual and predicted age, and thus demonstrated the value of age classifications derived from the transcriptional profiling of these two genes. The technique was used to establish the age structure of mosquito populations from two malaria-endemic areas in western Kenya. The population age structure determined by the transcriptional profiling method was consistent with that based on mosquito parity. This study demonstrates that the transcription profiling method based on two genes is valuable for age determination of natural mosquitoes, providing a new approach for determining a key life history trait of malaria vectors. PMID:23936017

  7. Dosage Compensation in the African Malaria Mosquito Anopheles gambiae

    PubMed Central

    Rose, Graham; Krzywinska, Elzbieta; Kim, Jan; Revuelta, Loic; Ferretti, Luca; Krzywinski, Jaroslaw

    2016-01-01

    Dosage compensation is the fundamental process by which gene expression from the male monosomic X chromosome and from the diploid set of autosomes is equalized. Various molecular mechanisms have evolved in different organisms to achieve this task. In Drosophila, genes on the male X chromosome are upregulated to the levels of expression from the two X chromosomes in females. To test whether a similar mechanism is operating in immature stages of Anopheles mosquitoes, we analyzed global gene expression in the Anopheles gambiae fourth instar larvae and pupae using high-coverage RNA-seq data. In pupae of both sexes, the median expression ratios of X-linked to autosomal genes (X:A) were close to 1.0, and within the ranges of expression ratios between the autosomal pairs, consistent with complete compensation. Gene-by-gene comparisons of expression in males and females revealed mild female bias, likely attributable to a deficit of male-biased X-linked genes. In larvae, male to female ratios of the X chromosome expression levels were more female biased than in pupae, suggesting that compensation may not be complete. No compensation mechanism appears to operate in male germline of early pupae. Confirmation of the existence of dosage compensation in A. gambiae lays the foundation for research into the components of dosage compensation machinery in this important vector species. PMID:26782933

  8. Transmission potential of Rickettsia felis infection by Anopheles gambiae mosquitoes

    PubMed Central

    Dieme, Constentin; Bechah, Yassina; Socolovschi, Cristina; Audoly, Gilles; Berenger, Jean-Michel; Faye, Ousmane; Raoult, Didier; Parola, Philippe

    2015-01-01

    A growing number of recent reports have implicated Rickettsia felis as a human pathogen, paralleling the increasing detection of R. felis in arthropod hosts across the globe, primarily in fleas. Here Anopheles gambiae mosquitoes, the primary malarial vectors in sub-Saharan Africa, were fed with either blood meal infected with R. felis or infected cellular media administered in membrane feeding systems. In addition, a group of mosquitoes was fed on R. felis-infected BALB/c mice. The acquisition and persistence of R. felis in mosquitoes was demonstrated by quantitative PCR detection of the bacteria up to day 15 postinfection. R. felis was detected in mosquito feces up to day 14. Furthermore, R. felis was visualized by immunofluorescence in salivary glands, in and around the gut, and in the ovaries, although no vertical transmission was observed. R. felis was also found in the cotton used for sucrose feeding after the mosquitoes were fed infected blood. Natural bites from R. felis-infected An. gambiae were able to cause transient rickettsemias in mice, indicating that this mosquito species has the potential to be a vector of R. felis infection. This is particularly important given the recent report of high prevalence of R. felis infection in patients with “fever of unknown origin” in malaria-endemic areas. PMID:26056256

  9. The role of hemocytes in A. gambiae antiplasmodial immunity

    PubMed Central

    Ramirez, Jose Luis; Garver, Lindsey S.; Brayner, Fábio André; Alves, Luiz Carlos; Rodrigues, Janneth; Molina-Cruz, Alvaro; Barillas-Mury, Carolina

    2013-01-01

    Hemocytes synthesize key components of the mosquito complement-like system, but their role in the activation of antiplasmodial responses has not been established. The effect of activating Toll signaling in hemocytes on Plasmodium survival was investigated by transferring hemocytes or cell-free hemolymph from donor mosquitoes in which the suppressor cactus was silenced. These transfers greatly enhanced antiplasmodial immunity, indicating that hemocytes are active players in the activation of the complement-like system, through an effector(s) regulated by the Toll pathway. A comparative analysis of hemocyte populations between susceptible (S) G3 and the refractory (R) L3-5 A. gambiae mosquito strains did not reveal significant differences under basal conditions or in response to Plasmodium berghei infection. The response of S mosquitoes to different Plasmodium species revealed similar kinetics following infection with P. berghei, P. yoelii or P. falciparum, but the strength of the priming response was stronger in less compatible mosquito-parasite pairs. The Toll, Imd, STAT or JNK signaling cascades were not essential for the production of hemocyte differentiation factor (HDF) in response to P. berghei infection, but disruption of Toll, STAT or JNK abolished hemocyte differentiation in response to HDF. We conclude that hemocytes are key mediators of A. gambiae antiplasmodial responses. PMID:23886925

  10. The role of hemocytes in Anopheles gambiae antiplasmodial immunity.

    PubMed

    Ramirez, Jose Luis; Garver, Lindsey S; Brayner, Fábio André; Alves, Luiz Carlos; Rodrigues, Janneth; Molina-Cruz, Alvaro; Barillas-Mury, Carolina

    2014-01-01

    Hemocytes synthesize key components of the mosquito complement-like system, but their role in the activation of antiplasmodial responses has not been established. The effect of activating Toll signaling in hemocytes on Plasmodium survival was investigated by transferring hemocytes or cell-free hemolymph from donor mosquitoes in which the suppressor cactus was silenced. These transfers greatly enhanced antiplasmodial immunity, indicating that hemocytes are active players in the activation of the complement-like system, through an effector/effectors regulated by the Toll pathway. A comparative analysis of hemocyte populations between susceptible G3 and the refractory L3-5 Anopheles gambiae mosquito strains did not reveal significant differences under basal conditions or in response to Plasmodium berghei infection. The response of susceptible mosquitoes to different Plasmodium species revealed similar kinetics following infection with P. berghei,P. yoelii or P. falciparum, but the strength of the priming response was stronger in less compatible mosquito-parasite pairs. The Toll, Imd,STAT or JNK signaling cascades were not essential for the production of the hemocyte differentiation factor (HDF) in response to P. berghei infection, but disruption of Toll, STAT or JNK abolished hemocyte differentiation in response to HDF. We conclude that hemocytes are key mediators of A. gambiae antiplasmodial responses. PMID:23886925

  11. The distribution of insecticide resistance in Anopheles gambiae s.l. populations from Cameroon: an update.

    PubMed

    Ndjemaï, Hamadou N M; Patchoké, Salomon; Atangana, Jean; Etang, Josiane; Simard, Fréderic; Bilong, Charles F Bilong; Reimer, Lisa; Cornel, Anthony; Lanzaro, Gregory C; Fondjo, Etienne

    2009-11-01

    Insecticides are a key component of vector-based malaria control programmes in Cameroon. As part of ongoing resistance surveillance efforts, Anopheles gambiae s.l. female mosquitoes were exposed to organochlorine (DDT), a carbamate (bendiocarb), an organophosphate (malathion), and three pyrethroids (deltamethrin, lambda-cyhalothrin and permethrin) in WHO bioassay test kits. Results indicated a higher level of resistance (reduced mortality and knockdown effect) to DDT and pyrethroids in populations of A. gambiae s.s. than in A. arabiensis. The West and East African knockdown resistance (kdr) mutations were found in both species but at much higher frequencies in A. gambiae s.s. The West Africa kdr mutant was also more frequent in the A. gambiae S form than in the M form. No resistance to bendiocarb and malathion was found. Carbamate and organophosphorous compounds could thus be used as alternatives in locations in Cameroon where pyrethroid-resistant populations are found. PMID:19155034

  12. Anopheles gambiae exploits the treehole ecosystem in western Kenya: a new urban malaria risk?

    PubMed

    Omlin, Francois X; Carlson, John C; Ogbunugafor, C Brandon; Hassanali, Ahmed

    2007-12-01

    At six sites in western Kenya, we explored the presence of Anopheles immature stages in treeholes. An. gambiae larvae were found in 19 species, 13 of which are exotic. The most common exotic species were Delonix regia, Jacaranda mimosipholia, and Eucalyptus citrodora. In Kisumu city, longitudinal assessments of 10 Flamboyant trees showed repeated presence of An. gambiae s.s. in treeholes with water. Production of Anopheles larvae did not correlate with habitat volume but with habitat height, showing a strong but statistically insignificant negative correlation. During a dry season, eggs recovered by rinsing dry treeholes hatched into 2.5 +/- 3.06 An. gambiae and 7.9 +/- 8.2 Aedes larvae. In cage experiments, An. gambiae s.s. laid more eggs in water originating from treeholes than in distilled or lake water, implying preference for ovipositing in this habitat. Our findings indicate that treeholes represent a hitherto unrecognized habitat for malaria vectors, which needs further studies. PMID:18165501

  13. A new species of Chaenusa Haliday sensu lato (Hymenoptera: Braconidae) from the Nearctic Region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chaenusa psillosae Kula, new species from the Nearctic Region is described. Specimens upon which the new species is described were reared from an undetermined species of Hydrellia Robineau-Desvoidy infesting Sagittaria latifolia Willd. A key to the New World species of Chaenusa sensu lato is amended...

  14. Antibodies against Borrelia burgdorferi sensu lato among Adults, Germany, 2008–2011

    PubMed Central

    Fingerle, Volker; Klier, Christiane; Thamm, Michael; Stark, Klaus

    2015-01-01

    To assess Borrelia burgdorferi sensu lato (the cause of Lyme borreliosis) seropositivity in Germany, we tested serum samples from health survey (2008–2011) participants. Seroprevalence was 5.8% among women and 13.0% among men; infection risk was highest among persons >60 years of age. Public health interventions, including education about risk factors and preventive measures, are needed. PMID:25531140

  15. Antibodies against Borrelia burgdorferi sensu lato among Adults, Germany, 2008-2011.

    PubMed

    Wilking, Hendrik; Fingerle, Volker; Klier, Christiane; Thamm, Michael; Stark, Klaus

    2015-01-01

    To assess Borrelia burgdorferi sensu lato (the cause of Lyme borreliosis) seropositivity in Germany, we tested serum samples from health survey (2008-2011) participants. Seroprevalence was 5.8% among women and 13.0% among men; infection risk was highest among persons >60 years of age. Public health interventions, including education about risk factors and preventive measures, are needed. PMID:25531140

  16. Multilocus sequence typing of Pseudomonas syringae sensu lato confirms previously described genomospecies and permits rapid identification.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, severe leaf spotting on parsley (Petroselinum crispum L.) has occurred in Monterey County, California. One of two different pathovars of Pseudomonas syringae sensu lato were isolated from diseased leaves from seven distinct outbreaks and twice from the same outbreak (2002 and 2009). Frag...

  17. How effective has tobacco tax increase been in the Gambia? A case study of tobacco control

    PubMed Central

    Nargis, Nigar; Manneh, Yahya; Krubally, Bakary; Jobe, Baboucarr; Ouma, Ahmed E Ogwell; Tcha-Kondor, Noureiny; Blecher, Evan H

    2016-01-01

    Objectives The objective of the present study was to evaluate how effective tobacco tax increase has been in increasing price of tobacco products and reducing tobacco consumption in the Gambia. In addition, it tests the hypothesis that tobacco tax revenue grows while tobacco consumption decreases as a result of tax and price increase. Setting The study is designed at the macroeconomic level to examine the import of tobacco products and revenue collected from tobacco taxation in a low-income setting. Participants The participants of this study are the government officials employed in the Ministry of Finance and Economic Affairs (MoFEA), the Gambia and the Gambia Revenue Authority, who are in charge of planning and implementing the tobacco tax policy in the Gambia. Interventions The study includes 2 consecutive interventions in tobacco tax policy in the Gambia. The first intervention was moving the tax base for the uniform specific excise tax on cigarettes from weight to pack of cigarettes in 2013. The second intervention involved increasing the excise and the environmental tax on tobacco products in 2014. Primary and secondary outcome measures The primary outcome measures were the cost, insurance and freight value and the price of tobacco products. The secondary outcome measures included the import of tobacco products and tobacco tax revenue. Results In 2013–2014, the Gambia MoFEA raised the specific excise rate, which increased price, reduced consumption and generated significantly more government revenue from tobacco products. This is a clear evidence of the win-win outcome of raising tobacco tax. In addition, the Gambia has set the example of harmonising tax rates between tobacco products that reduces the substitution between tobacco products. Conclusions The Gambia presents the best practice in tobacco taxation. There is need for documenting more country-specific evidence on the win-win outcome of raising tobacco tax. PMID:27566626

  18. Infertility resulting from transgenic I-PpoI male Anopheles gambiae in large cage trials

    PubMed Central

    Klein, T A; Windbichler, N; Deredec, A; Burt, A; Benedict, M Q

    2012-01-01

    Objectives Anopheles gambiae is the primary vector of malaria in sub-Saharan Africa and is a potential target of genetic control programs. We determined the capacity of male A. gambiae created by germline transformation to introduce infertility into stable age-distribution populations. We also determined effects of the transgenes on life history. Methods Stable age-distribution populations of A. gambiae mosquitoes were established in large indoor cages. Male mosquitoes carrying an I-PpoI homing endonuclease gene were introduced at ×5 and ×10 release rates where they competed with target male mosquitoes for matings. Similar trials were conducted in small cages with an additional ×1 release level. Results Infertility was successfully introduced into all target populations. In supporting experiments, complete female infertility was observed in all strains and species of the A. gambiae complex to which transgenic males were mated. Life history experiments demonstrated that reductions in I-PpoI male vigor exist in the form of reduced adult male emergence, longevity and competitiveness. Discussion A. gambiae I-PpoI males are capable of introducing high levels of infertility in target populations in indoor cage trials. This was accomplished despite losses of vigor resulting from the HEG transgene. These results motivate further trials of sexually I-PpoI A. gambiae in outdoor cage and field trials. PMID:22595271

  19. Inhibition of Anopheles gambiae odorant receptor function by mosquito repellents.

    PubMed

    Tsitoura, Panagiota; Koussis, Konstantinos; Iatrou, Kostas

    2015-03-20

    The identification of molecular targets of insect repellents has been a challenging task, with their effects on odorant receptors (ORs) remaining a debatable issue. Here, we describe a study on the effects of selected mosquito repellents, including the widely used repellent N,N-diethyl-meta-toluamide (DEET), on the function of specific ORs of the African malaria vector Anopheles gambiae. This study, which has been based on quantitative measurements of a Ca(2+)-activated photoprotein biosensor of recombinant OR function in an insect cell-based expression platform and a sequential compound addition protocol, revealed that heteromeric OR (ORx/Orco) function was susceptible to strong inhibition by all tested mosquito repellents except DEET. Moreover, our results demonstrated that the observed inhibition was due to efficient blocking of Orco (olfactory receptor coreceptor) function. This mechanism of repellent action, which is reported for the first time, is distinct from the mode of action of other characterized insect repellents including DEET. PMID:25657000

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

    PubMed

    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. PMID:27365445

  1. Inhibition of Anopheles gambiae Odorant Receptor Function by Mosquito Repellents*

    PubMed Central

    Tsitoura, Panagiota; Koussis, Konstantinos; Iatrou, Kostas

    2015-01-01

    The identification of molecular targets of insect repellents has been a challenging task, with their effects on odorant receptors (ORs) remaining a debatable issue. Here, we describe a study on the effects of selected mosquito repellents, including the widely used repellent N,N-diethyl-meta-toluamide (DEET), on the function of specific ORs of the African malaria vector Anopheles gambiae. This study, which has been based on quantitative measurements of a Ca2+-activated photoprotein biosensor of recombinant OR function in an insect cell-based expression platform and a sequential compound addition protocol, revealed that heteromeric OR (ORx/Orco) function was susceptible to strong inhibition by all tested mosquito repellents except DEET. Moreover, our results demonstrated that the observed inhibition was due to efficient blocking of Orco (olfactory receptor coreceptor) function. This mechanism of repellent action, which is reported for the first time, is distinct from the mode of action of other characterized insect repellents including DEET. PMID:25657000

  2. Bacterial associations reveal spatial population dynamics in Anopheles gambiae mosquitoes.

    PubMed

    Buck, Moritz; Nilsson, Louise K J; Brunius, Carl; Dabiré, Roch K; Hopkins, Richard; Terenius, Olle

    2016-01-01

    The intolerable burden of malaria has for too long plagued humanity and the prospect of eradicating malaria is an optimistic, but reachable, target in the 21(st) century. However, extensive knowledge is needed about the spatial structure of mosquito populations in order to develop effective interventions against malaria transmission. We hypothesized that the microbiota associated with a mosquito reflects acquisition of bacteria in different environments. By analyzing the whole-body bacterial flora of An. gambiae mosquitoes from Burkina Faso by 16 S amplicon sequencing, we found that the different environments gave each mosquito a specific bacterial profile. In addition, the bacterial profiles provided precise and predicting information on the spatial dynamics of the mosquito population as a whole and showed that the mosquitoes formed clear local populations within a meta-population network. We believe that using microbiotas as proxies for population structures will greatly aid improving the performance of vector interventions around the world. PMID:26960555

  3. Bacterial associations reveal spatial population dynamics in Anopheles gambiae mosquitoes

    PubMed Central

    Buck, Moritz; Nilsson, Louise K. J.; Brunius, Carl; Dabiré, Roch K.; Hopkins, Richard; Terenius, Olle

    2016-01-01

    The intolerable burden of malaria has for too long plagued humanity and the prospect of eradicating malaria is an optimistic, but reachable, target in the 21st century. However, extensive knowledge is needed about the spatial structure of mosquito populations in order to develop effective interventions against malaria transmission. We hypothesized that the microbiota associated with a mosquito reflects acquisition of bacteria in different environments. By analyzing the whole-body bacterial flora of An. gambiae mosquitoes from Burkina Faso by 16 S amplicon sequencing, we found that the different environments gave each mosquito a specific bacterial profile. In addition, the bacterial profiles provided precise and predicting information on the spatial dynamics of the mosquito population as a whole and showed that the mosquitoes formed clear local populations within a meta-population network. We believe that using microbiotas as proxies for population structures will greatly aid improving the performance of vector interventions around the world. PMID:26960555

  4. An epidemiological study of RSV infection in the Gambia.

    PubMed Central

    Weber, Martin W.; Milligan, Paul; Sanneh, Mariama; Awemoyi, Agnes; Dakour, Raduwan; Schneider, Gisela; Palmer, Ayo; Jallow, Mariatou; Oparaogu, Anslem; Whittle, Hilton; Mulholland, E. Kim; Greenwood, Brian M.

    2002-01-01

    OBJECTIVE: To describe the epidemiology of respiratory syncytial virus (RSV) infection in a developing country. METHODS: The work was carried out in three hospitals for primary cases and in the community for secondary cases in the western region of the Gambia, West Africa. RSV infection was diagnosed by immunofluorescence of nasopharyngeal aspirate samples in children younger than two years admitted to hospital with acute lower respiratory infection (ALRI). Routine records of all children with ALRI were analysed, and the incidence rates of ALRI, severe RSV-associated respiratory illness and hypoxaemic RSV infections were compared. A community-based study was undertaken to identify secondary cases and to obtain information about spread of the virus. FINDINGS: 4799 children with ALRI who were younger than two years and lived in the study area were admitted to the study hospitals: 421 had severe RSV-associated respiratory illness; 55 of these were hypoxaemic. Between 1994 and 1996, the observed incidence rate for ALRI in 100 children younger than one year living close to hospital was 9.6 cases per year; for severe RSV-associated respiratory illness 0.83; and for hypoxaemic RSV-associated respiratory illness 0.089. The proportion of all ALRI admissions due to RSV was 19%. Overall, 41% of children younger than five years in compounds in which cases lived and 42% in control compounds had evidence of RSV infection during the surveillance period. CONCLUSION: RSV is an important cause of ALRI leading to hospital admission in the Gambia. Morbidity is considerable and efforts at prevention are worthwhile. PMID:12163920

  5. A tuberculosis nationwide prevalence survey in Gambia, 2012

    PubMed Central

    Kendall, Lindsay; Bashorun, Adedapo; Linda, Christopher; Omoleke, Semeeh; Jeffries, David; Maane, Rahmatulai; Alorse, Beatrice Dei; Alorse, William Dei; Okoi, Catherine Bi; Mlaga, Kodjovi D; Kinteh, Ma Ansu; Donkor, Simon; de Jong, Bouke C; Antonio, Martin; d’Alessandro, Umberto

    2016-01-01

    Abstract Objective To estimate the population prevalence of active pulmonary tuberculosis in Gambia. Methods Between December 2011 and January 2013, people aged ≥ 15 years participating in a nationwide, multistage cluster survey were screened for active pulmonary tuberculosis with chest radiography and for tuberculosis symptoms. For diagnostic confirmation, sputum samples were collected from those whose screening were positive and subjected to fluorescence microscopy and liquid tuberculosis cultures. Multiple imputation and inverse probability weighting were used to estimate tuberculosis prevalence. Findings Of 100 678 people enumerated, 55 832 were eligible to participate and 43 100 (77.2%) of those participated. A majority of participants (42 942; 99.6%) were successfully screened for symptoms and by chest X-ray. Only 5948 (13.8%) were eligible for sputum examination, yielding 43 bacteriologically confirmed, 28 definite smear-positive and six probable smear-positive tuberculosis cases. Chest X-ray identified more tuberculosis cases (58/69) than did symptoms alone (43/71). The estimated prevalence of smear-positive and bacteriologically confirmed pulmonary tuberculosis were 90 (95% confidence interval, CI: 53–127) and 212 (95% CI: 152–272) per 100 000 population, respectively. Tuberculosis prevalence was higher in males (333; 95% CI: 233–433) and in the 35–54 year age group (355; 95% CI: 219–490). Conclusion The burden of tuberculosis remains high in Gambia but lower than earlier estimates of 490 per 100 000 population in 2010. Less than half of all cases would have been identified based on smear microscopy results alone. Successful control efforts will require interventions targeting men, increased access to radiography and more accurate, rapid diagnostic tests. PMID:27274595

  6. Efficacy of two different house screening interventions against exposure to malaria and anaemia in children in The Gambia: a randomized controlled trial

    PubMed Central

    Kirby, Matthew J; Ameh, David; Green, Clare; Jawara, Musa; Milligan, Paul J; Bottomley, Christian; Snell, Paul C; Conway, David J; Lindsay, Steve W

    2013-01-01

    Summary Background House screening should protect people against malaria. We assessed whether two types of house screening, full screening of windows, doors and closing eaves or installing netting ceilings in local houses, could reduce malaria vector house entry and anaemia in children, in an area of seasonal transmission. Methods 500 occupied houses in and near Farafenni town in The Gambia were randomly assigned to receive full screening, screened ceilings, or no screening, in an area where coverage of insecticide-treated nets was low. Screening was not treated with insecticide. Exposure to mosquitoes indoors was assessed by fortnightly light trap collections, and haemoglobin (Hb) concentration and the prevalence of anaemia and parasitaemia measured in children, aged 6 months to 10 years old, at the end of the transmission season. Findings The mean number of Anopheles gambiae sensu lato mosquitoes, the principal malaria vector, was reduced by 59% in houses with full screening (95% CI 46, 69; p<0.001) and 47% in houses with screened ceilings (95% CI 30, 60; p<0.001) compared with unscreened houses (37.5/trap/night). Anaemia prevalence (Hb <80g/L) was 19.0% among children in unscreened houses, compared to 12.3% with full screening, adjusted odds ratio (OR) 0.53 (0.29, 0.97; p=0.04), and 11.7% with screened ceilings, adjusted OR 0.51, (0.27, 0.96; p=0.04). Mean Hb concentration was higher in children living in fully screened houses and in houses with screened ceilings (104g/L in both groups), than those in unscreened houses (100g/L); adjusted estimates of the differences 3.7g/L (0.3, 7.2; p=0.03) and 4.2g/L (0.6, 7.7; p=0.02) respectively. There was no evidence of an effect on the prevalence of malaria infection. Interpretation House screening substantially reduced the number of mosquitoes inside houses and can contribute to prevention of anaemia in children. Funding Medical Research Council PMID:19732949

  7. Incorporating the effects of humidity in a mechanistic model of Anopheles gambiae mosquito population dynamics in the Sahel region of Africa

    PubMed Central

    2013-01-01

    Background Low levels of relative humidity are known to decrease the lifespan of mosquitoes. However, most current models of malaria transmission do not account for the effects of relative humidity on mosquito survival. In the Sahel, where relative humidity drops to levels <20% for several months of the year, we expect relative humidity to play a significant role in shaping the seasonal profile of mosquito populations. Here, we present a new formulation for Anopheles gambiae sensu lato (s.l.) mosquito survival as a function of temperature and relative humidity and investigate the effect of humidity on simulated mosquito populations. Methods Using existing observations on relationships between temperature, relative humidity and mosquito longevity, we developed a new equation for mosquito survival as a function of temperature and relative humidity. We collected simultaneous field observations on temperature, wind, relative humidity, and anopheline mosquito populations for two villages from the Sahel region of Africa, which are presented in this paper. We apply this equation to the environmental data and conduct numerical simulations of mosquito populations using the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS). Results Relative humidity drops to levels that are uncomfortable for mosquitoes at the end of the rainy season. In one village, Banizoumbou, water pools dried up and interrupted mosquito breeding shortly after the end of the rainy season. In this case, relative humidity had little effect on the mosquito population. However, in the other village, Zindarou, the relatively shallow water table led to water pools that persisted several months beyond the end of the rainy season. In this case, the decrease in mosquito survival due to relative humidity improved the model’s ability to reproduce the seasonal pattern of observed mosquito abundance. Conclusions We proposed a new equation to describe Anopheles gambiae s.l. mosquito survival as a

  8. Habitat Partitioning of Malaria Vectors in Nchelenge District, Zambia.

    PubMed

    Das, Smita; Muleba, Mbanga; Stevenson, Jennifer C; Norris, Douglas E

    2016-06-01

    Nchelenge District in Luapula Province, northern Zambia, experiences holoendemic malaria despite implementation of vector control programs. The major Anopheles vectors that contribute to Plasmodium falciparum transmission in this area had not previously been well defined. Three collections performed during the 2012 wet and dry seasons and the 2013 wet season revealed Anopheles funestus sensu stricto and Anopheles gambiae sensu stricto as the main vectors, where 80-85% of each collection was composed of An. funestus Both vectors were found to be highly anthropophilic, and An. funestus has higher sporozoite infection rates (SIRs) and entomological inoculation rates (EIRs) year-round compared with An. gambiae: SIRs of 1.8-3.0% and 0-2.5%, respectively, and EIRs of 3.7-41.5 infectious bites per 6-month period (ib/p/6mo) and 0-5.9 ib/p/6mo, respectively. Spatial and temporal changes in each vector's dynamics and bionomics were also observed. Anopheles funestus was the predominant vector in the villages near Kenani Stream in both wet and dry seasons, whereas An. gambiae was found to be the main vector in areas near Lake Mweru during the wet season. The vector data illustrate the need for broader temporal and spatial sampling in Nchelenge and present unique opportunities to further our understanding of malarial transmission and implications for malarial control in high-risk areas. PMID:27001755

  9. Mating type markers reveal high levels of heterothallism in Leptographium sensu lato.

    PubMed

    Duong, Tuan A; de Beer, Z Wilhelm; Wingfield, Brenda D; Wingfield, Michael J

    2016-04-01

    Species of Leptographium sensu lato are sap-stain fungi vectored by bark beetles and some species cause or are associated with tree diseases. Sexual states have been reported for more than 30 species in this group and these have been treated in the sexual genus Grosmannia. No sexual state is known for at least 59 additional species and these reside in the genus Leptographium. The discovery of sexual states for species of Leptographium relies mainly on the presence of fruiting bodies on host tissue at the time of isolation and/or intensive laboratory mating studies, which commonly have low levels of success. We developed mating-type markers to study sexual compatibility of species in Leptographium sensu lato. Using these markers, it was possible to identify mating types for 42 species and to determine thallism in many species for the first time. Surprisingly, the results showed that heterothallic and putatively heterothallic species are abundant (39 out of 42 species) in Leptographium sensu lato, and only three species were confirmed to be homothallic. The mating type markers developed in this study will be useful for future studies concerning mating type and sexual compatibility of species in this genus. PMID:27020155

  10. A test of the chromosomal theory of ecotypic speciation in Anopheles gambiae.

    PubMed

    Manoukis, Nicholas C; Powell, Jeffrey R; Touré, Mahamoudou B; Sacko, Adama; Edillo, Frances E; Coulibaly, Mamadou B; Traoré, Sekou F; Taylor, Charles E; Besansky, Nora J

    2008-02-26

    The role of chromosomal inversions in speciation has long been of interest to evolutionists. Recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. Anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated with ecotypes that mate assortatively. Here, we consider the potential role of paracentric inversions in promoting speciation in A. gambiae via "ecotypification," a term that refers to differentiation arising from local adaptation. In particular, we focus on the Bamako form, an ecotype characterized by low inversion polymorphism and fixation of an inversion, 2Rj, that is very rare or absent in all other forms of A. gambiae. The Bamako form has a restricted distribution by the upper Niger River and its tributaries that is associated with a distinctive type of larval habitat, laterite rock pools, hypothesized to be its optimal breeding site. We first present computer simulations to investigate whether the population dynamics of A. gambiae are consistent with chromosomal speciation by ecotypification. The models are parameterized using field observations on the various forms of A. gambiae that exist in Mali, West Africa. We then report on the distribution of larvae of this species collected from rock pools and more characteristic breeding sites nearby. Both the simulations and field observations support the thesis that speciation by ecotypification is occurring, or has occurred, prompting consideration of Bamako as an independent species. PMID:18287019

  11. Chronic non-communicable disease as a new epidemic in Africa: focus on The Gambia

    PubMed Central

    Omoleke, Semeeh A

    2013-01-01

    Introduction Recent epidemiological data suggest increasing burden of NCDs in many African countries but these diseases have not been given adequate attention due to the overwhelming burden of infectious diseases. There are no recent reports or studies on NCDs or related issues in The Gambia, consequently, this report intends to stimulate further epidemiological studies and also policy initiatives to forestall an epidemic. Methods Routine data on morbidity (in and out-patients), hospitalisation and mortality due to NCDs from health facilities in The Gambia between 2008 and 2011 were used. Other relevant data from multiple sources were also used. Results There is an increasing trend in the morbidity, hospitalisation and mortality due to NCDs in the Gambia between 2008 and 2011; 19.8%, 9.9% and 23.4% increments respectively. There is evidence of gender differences in these variables; more males suffer higher mortality from NCDs than females (p < 0.001). Furthermore, there is dearth of highly skilled health workforce as well as poor health infrastructures in The Gambia. Conclusion NCDs are becoming a public health challenge and the capacity to respond to NCDs in most African countries, particularly, The Gambia is very weak. There is need for a population-based study to accurately quantify the burden and their risk factors as a first step towards policy formulation and effective implementation. Furthermore, there is dire need for increased investments on health workforce as well as medical products and technologies towards addressing the consequences of this emerging epidemic. PMID:23646223

  12. The Cadherin Superfamily in Anopheles gambiae: a Comparative Study With Drosophila melanogaster

    PubMed Central

    Simões, Sérgio; Moita, Luís F.; Jacinto, António; Fernandes, Pedro

    2005-01-01

    The cadherin superfamily is a diverse and multifunctional group of proteins with extensive representation across genomes of phylogenetically distant species that is involved in cell–cell communication and adhesion. The mosquito Anopheles gambiae is an emerging model organism for the study of innate immunity and host–pathogen interactions, where the malaria parasite induces a profound rearrangement of the actin cytoskeleton at critical stages of infection. We have used bioinformatics tools to retrieve present sequence knowledge about the complete repertoire of cadherins in A. gambiae and compared it to that of the fruit fly, Drosophila melanogaster. In A. gambiae, we have identified 43 genes coding for cadherin extracellular domains that were re-annotated to 38 genes and represent an expansion of this gene family in comparison to other invertebrate organisms. The majority of Drosophila cadherins show a 1 : 1 Anopheles orthologue, but we have observed a remarkable expansion in some groups in A. gambiae, such as N-cadherins, that were recently shown to have a role in the olfactory system of the fruit fly. In vivo dsRNA silencing of overrepresented genes in A. gambiae and other genes showing expression at critical tissues for parasite infection will likely advance our understanding of the problems of host preference and host–pathogen interactions in this mosquito species. PMID:18629193

  13. [Anopheles gambiae, major malaria vector in Logbessou, a peri-urban area of Douala (Cameroon)].

    PubMed

    Akono, P Ntonga; Tonga, C; Mbida, J A Mbida; Hondt, O E Ngo; Ambene, P Awono; Ndo, C; Magne, G Tamdem; Peka, M F; Ngaha, R; Lehman, L G

    2015-12-01

    An entomological survey was carried out from August to November 2013, in order to determine the vector system of a building site for social housing in a coastal periurban district of Douala (Cameroon). Mosquito larvae were collected and adult endophilic mosquitoes captured on volunteers, for a total sample of 4897 mosquitoes. Morpho-taxonomic techniques alongside molecular techniques enabled the identification of 4 species, all aggressive to humans: Cx. pipiens (22.3%), Ae. albopictus (0.3%), An. coluzzii and An. gambiae (77.4%). The overall average biting rate recorded was 41.73 bites/person/night (b/p/n). An. gambiae s.l. represents 90.82% of this aggressive fauna, followed by Cx. pipiens (8.58%) and Ae. albopictus (0.6%). The detection of CSP showed that An. gambiae was responsible for 100% of P. falciparum transmission. The overall mean Entomological Inoculation Rate (EIR) was 3.94 ib/p/n. Female An. gambiae mortality rates were 14.47%, 82.5% and 100% respectively with DDT, permethrin and deltamethrin. The proliferation of An. gambiae in this area during raining season, at the detriment of An. coluzzii Coetze & Wilkerson and An. melas Theobald known to be major malaria vectors in island and coastal areas of Africa, may owe to the forest that still colonises this coastal peri-urban locality. Residents should therefore make use of deltamethrin based protective measures. PMID:26419486

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

    SciTech Connect

    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.

  15. A description and morphometric comparison of eggs of species of the Anopheles gambiae complex.

    PubMed

    Lounibos, L P; Coetzee, M; Duzak, D; Nishimura, N; Linley, J R; Service, M W; Cornel, A J; Fontenille, D; Mukwaya, L G

    1999-06-01

    Eggs of the 6 named species of the Anopheles gambiae complex are described from scanning electron micrographs of specimens obtained from laboratory colonies or wild-caught females. Morphometric measurements of eggs from 5 sources of Anopheles arabiensis, 2 of Anopheles gambiae, one of Anopheles quadriannulatus, 2 of Anopheles bwambae, 2 of Anopheles merus, and one of Anopheles melas are compared, and relationships are analyzed by multivariate statistics. No morphologic characters were species-diagnostic, although tendencies of the saltwater species An. merus and An. melas to have wider decks and shorter floats were confirmed. Species and populations overlapped considerably in principal components and discriminant function analyses based on 10 attributes of eggs. Nevertheless, discriminant functions revealed similarities in eggs of species believed to be most closely related, namely, An. gambiae and An. arabiensis, An. merus and An. melas, and An. quadriannulatus and An. bwambae. PMID:10412112

  16. Seroepidemiological study of African horse sickness virus in The Gambia.

    PubMed Central

    Staeuber, N; Fye, B; Zinsstag, J; McCullough, K C

    1993-01-01

    An indirect enzyme-linked immunosorbent assay was used for the screening of horse sera from The Gambia for antibodies against African horse sickness virus (AHSV). The AHSV antigen used for coating was semipurified according to the method of Manning and Chen (Curr. Microbiol. 4:381, 1980); control mock-infected Vero cell antigen was treated in the same manner. A total of 459 horse serum samples were assayed at a single dilution (1:10), and their reactivities were compared with those of reference positive anti-AHSV and reference negative horse sera. A total of 81% of the horse serum samples clearly contained antibodies against AHSV; this consisted of 18% (of the total number of serum samples) strongly positive, 46.5% moderately positive, and 16.5% weakly but still clearly positive. Such results suggest a high prevalence of AHSV in the regions from whence the samples originated. Reports from investigations in other countries in this area of West Africa have also shown a high prevalence for anti-AHSV antibodies in equids. The question is raised as to how the animals became seropositive and whether the observations represent an increased resistance of horses living in a region in which AHS is enzootic. PMID:8370760

  17. Maternal mortality in rural Gambia: levels, causes and contributing factors.

    PubMed Central

    Walraven, G.; Telfer, M.; Rowley, J.; Ronsmans, C.

    2000-01-01

    A demographic study carried out in a rural area of the Gambia between January 1993 and December 1998 recorded 74 deaths among women aged 15-49 years. Reported here is an estimation of maternal mortality among these 74 deaths based on a survey of reproductive age mortality, which identified 18 maternal deaths by verbal autopsy. Over the same period there were 4245 live births in the study area, giving a maternal mortality ratio of 424 per 100,000 live births. This maternal mortality estimate is substantially lower than estimates made in the 1980s, which ranged from 1005 to 2362 per 100,000 live births, in the same area. A total of 9 of the 18 deaths had a direct obstetric cause--haemorrhage (6 deaths), early pregnancy (2), and obstructed labour (1). Indirect causes of obstetric deaths were anaemia (4 deaths), hepatitis (1), and undetermined (4). Low standards of health care for obstetric referrals, failure to recognize the severity of the problem at the community level, delays in starting the decision-making process to seek health care, lack of transport, and substandard primary health care were identified more than once as probable or possible contributing factors to these maternal deaths. PMID:10859854

  18. Milk production of West African Dwarf goats in the Gambia.

    PubMed

    Jaitner, J; Njie, M; Corr, N; Dempfle, L

    2006-04-01

    Goats are important in the low-input systems of West Africa and their main importance lies in their role for income and saving. In addition, it is known that milk offtake for home consumption is also important. In order to obtain information about the real importance of milk offtake, a recording scheme was operated in 27 villages in the Central River Division of The Gambia from July 1998 until January 2000. Detailed information was obtained from about 1500 kiddings. In the recording scheme, any sheep being milked as well as the goats of the International Trypanotolerance Centre nucleus flock were also recorded. In the villages, 36% of all lactations were used for milk offtake, but the fraction milked was lower for the first two lactations. The average length of lactation was 127 days and the average daily milk offtake was 0.18 L. Goats are milked once a day and the residual milk is left for the kids. Milking starts about one week after parturition and stops when the goat becomes pregnant or the kid(s) die or the goat is drying off. The repeatability of the 90-day milk offtake was 0.24 +/- 0.09. Sixty-five percent of goat owner were women and a large fraction of goat owners also owned cattle. Goat milk was used exclusively for home consumption. It is concluded that in breeding and extension work more attention should be given to aspects of milk production. PMID:16986773

  19. Inactivation of Anopheles gambiae Glutathione Transferase ε2 by Epiphyllocoumarin

    PubMed Central

    Marimo, Patience; Hayeshi, Rose; Mukanganyama, Stanley

    2016-01-01

    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. PMID:26925266

  20. Implementing a nationwide insecticide-impregnated bednet programme in The Gambia.

    PubMed

    Cham, M K; D'Alessandro, U; Todd, J; Bennett, S; Fegan, G; Cham, B A; Greenwood, B M

    1996-09-01

    Earlier studies in The Gambia suggested that the use of impregnated bednets might prove to be a useful malaria control strategy. Based on the results of these studies, in 1992 the Government of The Gambia was encouraged to initiate a National Impregnated Bednet Programme (NIBP) as part of the National Malaria Control Programme Strategy. This paper describes the implementation process/procedure of the NIBP. Evaluation results showed that, overall, 83% of the bednets surveyed has been impregnated, and 77% of children under the age of five years and 78% of women of childbearing age were reported to be sleeping under impregnated bednets. PMID:10160374

  1. Cuticular-hydrocarbon discrimination between Anopheles gambiae s.s. and An. arabiensis larval karyotypes.

    PubMed

    Anyanwu, G I; Davies, D H; Molyneux, D H; Priestman, A

    2001-12-01

    Examination of chromatograms of karyotyped larvae of Anopheles gambiae s.s. and Anopheles arabiensis has revealed that there are differences in the profile of their epicuticular hydrocarbons. A discriminant analysis of the quantitative hydrocarbon data has shown that the An. gambiae Mopti 2Rbc/bc karyotype from Mali could be separated from the Forest 2La/a karyotype from Liberia in > 80% of cases. Similar analysis permitted > 80% separation of individuals of two karyotypes of Anopheles arabiensis: 2Rab/ + from Burkina Faso, and 2Rb/b from Madagascar. PMID:11784439

  2. Molecular epidemiology and in vitro antifungal susceptibility testing of 108 clinical Cryptococcus neoformans sensu lato and Cryptococcus gattii sensu lato isolates from Denmark.

    PubMed

    Hagen, Ferry; Hare Jensen, Rasmus; Meis, Jacques F; Arendrup, Maiken Cavling

    2016-09-01

    Cryptococcosis is mainly caused by members of the Cryptococcus gattii/Cryptococcus neoformans species complexes. Here, we report the molecular characterisation and in vitro antifungal susceptibility of Danish clinical cryptococcal isolates. Species, genotype, serotype and mating type were determined by amplified fragment length polymorphism (AFLP) fingerprinting and qPCR. EUCAST E.Def 7.2 MICs were determined for amphotericin B, flucytosine, fluconazole, voriconazole and isavuconazole. Most isolates were C. neoformans (serotype A; n = 66) and belonged to genotype AFLP1/VNI (n = 61) or AFLP1B/VNII (n = 5) followed by Cryptococcus deneoformans (serotype D; genotype AFLP2, n = 20), C. neoformans × C. deneoformans hybrids (serotype AD; genotype AFLP3, n = 13) and Cryptococcus curvatus (n = 2). Six isolates were C. gattii sensu lato, and one isolate was a C. deneoformans × C. gattii hybrid (genotype AFLP8). All isolates were amphotericin B susceptible. Flucytosine susceptibility was uniform MIC50 of 4-8 mg l(-1) except for C. curvatus (MICs >32 mg l(-1) ). Cryptococcus gattii sensu lato isolates were somewhat less susceptible to the azoles. MICs of fluconazole (>32 mg l(-1) ), voriconazole (≥0.5 mg l(-1) ) and isavuconazole (0.06 and 0.25 mg l(-1) respectively) were elevated compared to the wild-type population for 1/19 C. deneoformans and 1/2 C. curvatus isolates. Flucytosine MIC was elevated for 1/61 C. neoformans (>32 mg l(-1) ). Antifungal susceptibility revealed species-specific differential susceptibility, but suggested acquired resistance was an infrequent phenomenon. PMID:27061834

  3. Revisiting phylogenetic diversity and cryptic species of Cenococcum geophilum sensu lato.

    PubMed

    Obase, Keisuke; Douhan, Greg W; Matsuda, Yosuke; Smith, Matthew E

    2016-08-01

    The fungus Cenococcum geophilum Fr. (Dothideomycetes, Ascomycota) is one of the most common ectomycorrhizal fungi in boreal to temperate regions. A series of molecular studies has demonstrated that C. geophilum is monophyletic but a heterogeneous species or a species complex. Here, we revisit the phylogenetic diversity of C. geophilum sensu lato from a regional to intercontinental scale by using new data from Florida (USA) along with existing data in GenBank from Japan, Europe, and North America. The combination of internal transcribed spacer (ITS) ribosomal DNA and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene resolved six well-supported lineages (87-100 % bootstrap values) that are closely related to each other and a seventh lineage that is phylogenetically distinct. A multi-locus analysis (small subunit (SSU), large subunit (LSU), translational elongation factor (TEF), and the largest and second-largest subunits of RNA polymerase II (RPB1 and RPB2)) revealed that the divergent lineage is the sister group to all other known Cenococcum isolates. Isolates of the divergent lineage grow fast on nutrient media and do not form ectomycorrhizas on seedlings of several pine and oak species. Our results indicate that C. geophilum sensu lato includes more phylogenetically distinct cryptic species than have previously been reported. Furthermore, the divergent lineage appears to be a non-mycorrhizal sister group. We discuss the phylogenetic diversity of C. geophilum sensu lato and argue in favor of species recognition based on phylogenetic and ecological information in addition to morphological characteristics. A new genus and species (Pseudocenococcum floridanum gen. et sp. nov.) is proposed to accommodate a divergent and putatively non-mycorrhizal lineage. PMID:26968743

  4. A High-Affinity Adenosine Kinase from Anopheles Gambiae

    SciTech Connect

    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.

  5. "Denuy Jangal Seen Bopp" (They Teach Themselves): Children's Music Learning in the Gambia

    ERIC Educational Resources Information Center

    Koops, Lisa Huisman

    2010-01-01

    The author investigated the teaching and learning processes among children in a suburban community of The Gambia, West Africa. Participants included children and adults in the community (N = 101). The researcher used ethnographic techniques of participant and nonparticipant observation, interviews, and song and chant collection. Data consisted of…

  6. Health consequences of female genital mutilation/cutting in the Gambia, evidence into action

    PubMed Central

    2011-01-01

    Background Female Genital Mutilation/Cutting (FGM/C) is a harmful traditional practice with severe health complications, deeply rooted in many Sub-Saharan African countries. In The Gambia, the prevalence of FGM/C is 78.3% in women aged between 15 and 49 years. The objective of this study is to perform a first evaluation of the magnitude of the health consequences of FGM/C in The Gambia. Methods Data were collected on types of FGM/C and health consequences of each type of FGM/C from 871 female patients who consulted for any problem requiring a medical gynaecologic examination and who had undergone FGM/C in The Gambia. Results The prevalence of patients with different types of FGM/C were: type I, 66.2%; type II, 26.3%; and type III, 7.5%. Complications due to FGM/C were found in 299 of the 871 patients (34.3%). Even type I, the form of FGM/C of least anatomical extent, presented complications in 1 of 5 girls and women examined. Conclusion This study shows that FGM/C is still practiced in all the six regions of The Gambia, the most common form being type I, followed by type II. All forms of FGM/C, including type I, produce significantly high percentages of complications, especially infections. PMID:21967670

  7. Role of Testis-Specific Gene Expression in Sex-Chromosome Evolution of Anopheles gambiae

    PubMed Central

    Baker, Dean A.; Russell, Steven

    2011-01-01

    Gene expression in Anopheles gambiae shows a deficiency of testis-expressed genes on the X chromosome associated with an excessive movement of retrogene duplication. We suggest that the degeneration of sex chromosomes in this monandrous species is likely the result of pressures from X inactivation, dosage compensation, and sexual antagonism. PMID:21890740

  8. Development of Indicators for Educational Planning: Brazil, Cambodia, Estonia, Gambia, Lithuania, Thailand.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). International Inst. for Educational Planning.

    This publication presents the outcomes of a distance education course on development and dissemination of indicators used for educational planning. The course took place from November 2000 to February 2001 and was attended by representatives from the ministries of education of Brazil, Cambodia, Estonia, Gambia, Lithuania, and Thailand. The overall…

  9. Closing the Education Gender Gap: Estimating the Impact of Girls' Scholarship Program in the Gambia

    ERIC Educational Resources Information Center

    Gajigo, Ousman

    2016-01-01

    This paper estimates the impact of a school fee elimination program for female secondary students in The Gambia to reduce gender disparity in education. To assess the impact of the program, two nationally representative household surveys were used (1998 and 2002/2003). By 2002/2003, about half of the districts in the country had benefited from the…

  10. Life on the edge: African malaria mosquito (Anopheles gambiae s. l.) larvae are amphibious

    NASA Astrophysics Data System (ADS)

    Miller, James R.; Huang, Juan; Vulule, John; Walker, Edward D.

    2007-03-01

    Anopheles gambiae s.l. is the main vector of malaria in Sub-Saharan Africa. Here, an estimated 1 million people die every year from this disease. Despite considerable research on An. gambiae that increasingly explores sub-organismal phenomena, important facets of the field biology of this deadly insect are yet being discovered. In the current study, we used simple observational tools to reveal that the habitat of larval An. gambiae is not limited within the boundaries of temporary mud puddles, as has been the accepted generalization. Thus, control tactics aimed at immatures must consider zones larger than puddles per se. In fact, eggs are more likely to be found outside than inside puddles. Eggs can develop and larvae can emerge on mud. Larvae are then capable of three distinct modes of terrestrial displacement (two active and one passive), whereby, they can reach standing water. On mud bearing a film of water, larvae actively displace backwards by sinusoidal undulations shown to be only a slight variation of the swimming motor program. On drying mud, larvae switch to a slower and forward form of active locomotion resembling that of a crawling caterpillar. During rains, small larvae may be passively displaced by flowing rainwater so as to be deposited into puddles. These capabilities for being amphibious, along with very rapid growth and development, help explain how An. gambiae thrives in a highly uncertain and often hostile larval environment.

  11. Crepuscular Behavioral Variation and Profiling of Opsin Genes in Anopheles gambiae and Anopheles stephensi (Diptera: Culicidae)

    PubMed Central

    Jenkins, Adam M.; Muskavitch, Marc A. T.

    2015-01-01

    We understand little about photopreference and the molecular mechanisms governing vision-dependent behavior in vector mosquitoes. Investigations of the influence of photopreference on adult mosquito behaviors such as endophagy and exophagy and endophily and exophily will enhance our ability to develop and deploy vector-targeted interventions and monitoring techniques. Our laboratory-based analyses have revealed that crepuscular period photopreference differs between An. gambiae and An. stephensi. We employed qRT-PCR to assess crepuscular transcriptional expression patterns of long wavelength-, short wavelength-, and ultraviolet wavelength-sensing opsins (i.e., rhodopsin-class G-protein coupled receptors) in An. gambiae and in An. stephensi. Transcript levels do not exhibit consistent differences between species across diurnal cycles, indicating that differences in transcript abundances within this gene set are not correlated with these behavioral differences. Using developmentally staged and gender-specific RNAseq data sets in An. gambiae, we show that long wavelength-sensing opsins are expressed in two different patterns (one set expressed during larval stages, and one set expressed during adult stages), while short wavelength- and ultraviolet wavelength-sensing opsins exhibit increased expression during adult stages. Genomic organization of An. gambiae opsins suggests paralogous gene expansion of long wavelength-sensing opsins in comparison with An. stephensi. We speculate that this difference in gene number may contribute to variation between these species in photopreference behavior (e.g., visual sensitivity). PMID:26334802

  12. Greenhouse gas mitigation options in the forestry sector of The Gambia: Analysis based on COMAP model

    SciTech Connect

    Jallow, B.P.

    1996-12-31

    Results of the 1993 Greenhouse Gas Emissions Inventory of The Gambia showed net CO{sub 2} emissions of over (1.66 x 10{sup 6} tons) and 1% was due to uptake by plantations (0.01 x 10{sup 6} tons). This is a clear indication that there is need to identify changes in the land-use policy, law and tenure that discourages forest clearing at the same time significantly influencing the sustainable distribution of land among forestry, rangeland and livestock, and agriculture. About 11% of the total area of The Gambia is either fallow or barren flats that once supported vegetation and hence is still capable of supporting vegetation. The US Country Study Programme has provided the Government of The Gambia through the National Climate Committee funds to conduct Assessment of Mitigation Options to Reduce Greenhouse Gas Emissions. The Forestry Sector is one area for which assessment is being conducted. The assessment is expected to end in September 1996. The Comprehensive Mitigation Analysis Process (COMAP) is one of the Models supplied to the National Climate Committee by the Lawrence Berkeley Laboratory, on behalf of the US Country Study Programme, and is being used to conduct the analysis in The Gambia.

  13. Seasonal climate effects anemotaxis in newly emerged adult anopheles gambiae giles in Mali, West Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The direction and magnitude of movement of the malaria vector Anopheles gambiae Giles has been of great interest to medical entomologists for over 70 years. This direction of movement is likely to be affected by many factors, from environmental conditions and stage of life history of the mosquito to...

  14. Apolipophorin-III Mediates Antiplasmodial Epithelial Responses in Anopheles gambiae (G3) Mosquitoes

    PubMed Central

    Jo, Yong Hun; Oh, Seung Han; Kumar, Sanjeev; Noh, Mi Young; Lee, Yong Seok; Cha, Sung-Jae; Seo, Sook Jae; Kim, Iksoo; Han, Yeon Soo; Barillas-Mury, Carolina

    2010-01-01

    Background Apolipophorin-III (ApoLp-III) is known to play an important role in lipid transport and innate immunity in lepidopteran insects. However, there is no evidence of involvement of ApoLp-IIIs in the immune responses of dipteran insects such as Drosophila and mosquitoes. Methodology/Principal Findings We report the molecular and functional characterization of An. gambiae apolipophorin-III (AgApoLp-III). Mosquito ApoLp-IIIs have diverged extensively from those of lepidopteran insects; however, the predicted tertiary structure of AgApoLp-III is similar to that of Manduca sexta (tobacco hornworm). We found that AgApoLp-III mRNA expression is strongly induced in the midgut of An. gambiae (G3 strain) mosquitoes in response to Plasmodium berghei infection. Furthermore, immunofluorescence stainings revealed that high levels of AgApoLp-III protein accumulate in the cytoplasm of Plasmodium-invaded cells and AgApoLp-III silencing increases the intensity of P. berghei infection by five fold. Conclusion There are broad differences in the midgut epithelial responses to Plasmodium invasion between An. gambiae strains. In the G3 strain of An. gambiae AgApoLp-III participates in midgut epithelial defense responses that limit Plasmodium infection. PMID:21072214

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

    PubMed

    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. PMID:25417803

  16. Barriers to Participation and Retention: Engaging and Returning "Out of School" Children in the Gambia

    ERIC Educational Resources Information Center

    Daly, Angela; Mbenga, Basiru; Camara, Alpha

    2016-01-01

    This study explores the phenomenon of out-of-school children in the Gambia through the perspectives of children and families. Using mixed methods, the study reports the extent of school participation. Interviews with urban and rural out-of-school children reveal their experiences and reasons for non-enrolment or leaving school. The study…

  17. Developmental and evolutionary basis for drought tolerance of the Anopheles gambiae embryo

    PubMed Central

    Goltsev, Yury; Rezende, Gustavo L.; Vranizan, Karen; Lanzaro, Greg

    2009-01-01

    During the evolution of the Diptera there is a dramatic modification of the embryonic ectoderm, whereby mosquitoes contain separate amnion and serosa lineages while higher flies such as D. melanogaster contain a single amnioserosa. Whole-genome transcriptome assays were performed with isolated serosa from A. gambiae embryos. These assays identified a large number of genes implicated in the production of the larval cuticle. In D. melanogaster, these genes are activated just once during embryogenesis, during late stages where they are used for the production of the larval cuticle. Evidence is presented that the serosal cells secrete a dedicated serosal cuticle, which protects A. gambiae embryos from desiccation. Detailed temporal microarray assays of mosquito gene expression profiles revealed that the cuticular genes display biphasic expression during A. gambiae embryogenesis, first in the serosa of early embryos and then again during late stages as seen in D. melanogaster. We discuss how evolutionary modifications in the well-defined dorsal-ventral patterning network led to the wholesale deployment of the cuticle biosynthesis pathway in early embryos of A. gambiae. PMID:19298808

  18. Crepuscular Behavioral Variation and Profiling of Opsin Genes in Anopheles gambiae and Anopheles stephensi (Diptera: Culicidae).

    PubMed

    Jenkins, Adam M; Muskavitch, Marc A T

    2015-05-01

    We understand little about photo-preference and the molecular mechanisms governing vision-dependent behavior in vector mosquitoes. Investigations of the influence of photo-preference on adult mosquito behaviors such as endophagy and exophagy and endophily and exophily will enhance our ability to develop and deploy vector-targeted interventions and monitoring techniques. Our laboratory-based analyses have revealed that crepuscular period photo-preference differs between An. gambiae and An. stephensi. We employed qRT-PCR to assess crepuscular transcriptional expression patterns of long wavelength-, short wavelength-, and ultraviolet wavelength-sensing opsins (i.e., rhodopsin-class G-protein coupled receptors) in An. gambiae and in An. stephensi. Transcript levels do not exhibit consistent differences between species across diurnal cycles, indicating that differences in transcript abundances within this gene set are not correlated with these behavioral differences. Using developmentally staged and gender-specific RNAseq data sets in An. gambiae, we show that long wavelength-sensing opsins are expressed in two different patterns (one set expressed during larval stages, and one set expressed during adult stages), while short wavelength- and ultraviolet wavelength-sensing opsins exhibit increased expression during adult stages. Genomic organization of An. gambiae opsins suggests paralogous gene expansion of long wavelength-sensing opsins in comparison with An. stephensi. We speculate that this difference in gene number may contribute to variation between these species in photo-preference behavior (e.g., visual sensitivity). PMID:26334802

  19. Separation of Anopheles merus from freshwater Anopheles gambiae by salinity tolerance test and morphological characters.

    PubMed

    Mosha, F W; Mutero, C M

    1982-12-01

    The separation methods for Anopheles merus from freshwater A. gambiae s.l. involving the use of salinity tolerance test, sensilla coeloconica, palpal ratio and palpal bands were evaluated for a period of one year on a total of about 340 mosquitoes. The salinity tolerance test method was found to be quite simple and reliable but unsuitable in disease transmission studies due to an interval of 2-3 days between the collection and dissection periods and also due to the fact that only a fraction of the mosquito sample is generally identified by this method. Although significantly higher proportions of sensilla coeloconica and palpal ratio were observed in A. merus as compared to freshwater A. gambiae s.l. these characters were found quite unreliable due to their overlapping between two mosquito groups. Sensilla coeloconica and palpal ratio used separately could separate respective percentages of 11.4 and 11.8 A. merus from freshwater A. gambiae s.l., while in combination they separated up to 40.9%. Percentages 4-banded palp mosquitoes accounted for about 32% in A. merus and 19% in freshwater A. gambiae s.l. All these characters also displayed some seasonal variations in the two mosquito groups. PMID:6926942

  20. Comparative Genomics of Listeria Sensu Lato: Genus-Wide Differences in Evolutionary Dynamics and the Progressive Gain of Complex, Potentially Pathogenicity-Related Traits through Lateral Gene Transfer.

    PubMed

    Chiara, Matteo; Caruso, Marta; D'Erchia, Anna Maria; Manzari, Caterina; Fraccalvieri, Rosa; Goffredo, Elisa; Latorre, Laura; Miccolupo, Angela; Padalino, Iolanda; Santagada, Gianfranco; Chiocco, Doriano; Pesole, Graziano; Horner, David S; Parisi, Antonio

    2015-08-01

    Historically, genome-wide and molecular characterization of the genus Listeria has concentrated on the important human pathogen Listeria monocytogenes and a small number of closely related species, together termed Listeria sensu strictu. More recently, a number of genome sequences for more basal, and nonpathogenic, members of the Listeria genus have become available, facilitating a wider perspective on the evolution of pathogenicity and genome level evolutionary dynamics within the entire genus (termed Listeria sensu lato). Here, we have sequenced the genomes of additional Listeria fleischmannii and Listeria newyorkensis isolates and explored the dynamics of genome evolution in Listeria sensu lato. Our analyses suggest that acquisition of genetic material through gene duplication and divergence as well as through lateral gene transfer (mostly from outside Listeria) is widespread throughout the genus. Novel genetic material is apparently subject to rapid turnover. Multiple lines of evidence point to significant differences in evolutionary dynamics between the most basal Listeria subclade and all other congeners, including both sensu strictu and other sensu lato isolates. Strikingly, these differences are likely attributable to stochastic, population-level processes and contribute to observed variation in genome size across the genus. Notably, our analyses indicate that the common ancestor of Listeria sensu lato lacked flagella, which were acquired by lateral gene transfer by a common ancestor of Listeria grayi and Listeria sensu strictu, whereas a recently functionally characterized pathogenicity island, responsible for the capacity to produce cobalamin and utilize ethanolamine/propane-2-diol, was acquired in an ancestor of Listeria sensu strictu. PMID:26185097

  1. Comparative Genomics of Listeria Sensu Lato: Genus-Wide Differences in Evolutionary Dynamics and the Progressive Gain of Complex, Potentially Pathogenicity-Related Traits through Lateral Gene Transfer

    PubMed Central

    Chiara, Matteo; Caruso, Marta; D’Erchia, Anna Maria; Manzari, Caterina; Fraccalvieri, Rosa; Goffredo, Elisa; Latorre, Laura; Miccolupo, Angela; Padalino, Iolanda; Santagada, Gianfranco; Chiocco, Doriano; Pesole, Graziano; Horner, David S.; Parisi, Antonio

    2015-01-01

    Historically, genome-wide and molecular characterization of the genus Listeria has concentrated on the important human pathogen Listeria monocytogenes and a small number of closely related species, together termed Listeria sensu strictu. More recently, a number of genome sequences for more basal, and nonpathogenic, members of the Listeria genus have become available, facilitating a wider perspective on the evolution of pathogenicity and genome level evolutionary dynamics within the entire genus (termed Listeria sensu lato). Here, we have sequenced the genomes of additional Listeria fleischmannii and Listeria newyorkensis isolates and explored the dynamics of genome evolution in Listeria sensu lato. Our analyses suggest that acquisition of genetic material through gene duplication and divergence as well as through lateral gene transfer (mostly from outside Listeria) is widespread throughout the genus. Novel genetic material is apparently subject to rapid turnover. Multiple lines of evidence point to significant differences in evolutionary dynamics between the most basal Listeria subclade and all other congeners, including both sensu strictu and other sensu lato isolates. Strikingly, these differences are likely attributable to stochastic, population-level processes and contribute to observed variation in genome size across the genus. Notably, our analyses indicate that the common ancestor of Listeria sensu lato lacked flagella, which were acquired by lateral gene transfer by a common ancestor of Listeria grayi and Listeria sensu strictu, whereas a recently functionally characterized pathogenicity island, responsible for the capacity to produce cobalamin and utilize ethanolamine/propane-2-diol, was acquired in an ancestor of Listeria sensu strictu. PMID:26185097

  2. Discriminative feeding behaviour of Anopheles gambiae s.s. on endemic plants in western Kenya

    PubMed Central

    Manda, H.; Gouagna, L. C.; Nyandat, E.; Kabiru, E. W.; Jackson, R. R.; Foster, W. A.; Githure, J. I.; Beier, J. C.; Hassanali, A.

    2009-01-01

    Anopheles gambiae Giles s.s. (Diptera: Culicidae) is known to feed on plant sugars, but this is the first experimental study to consider whether it discriminates between plant species. Thirteen perennial plant species were selected on the basis of their local availability within the vicinity of human dwellings and larval habitats of An. gambiae s.s. in western Kenya. Groups of 100 or 200 mosquitoes were released into cages either with a cutting of one plant type at a time (single-plant assay) or with cuttings of all 13 plants simultaneously (choice assay), respectively, and left overnight. In the choice assay, direct observations of the percentages of mosquitoes perching or feeding on each plant were recorded over four 1-h periods each night. For both types of assay, mosquitoes were recaptured and the percentage that had fed on plants was assessed by testing them individually for the presence of fructose. To identify which plants the choice-assay mosquitoes had fed on, gas chromatography (GC) profiles of samples of mosquito homogenates were compared with GC profiles of extracts from relevant parts of each plant. Four of the plants that were observed to have been fed on most frequently in the choice assay (Parthenium hysterophorus L., Tecoma stans L., Ricinus communis L., and Senna didymobotrya Fresen) were also shown to have been ingested most often by mosquitoes in both types of assay, suggesting that An. gambiae is differentially responsive to this range of plants, regardless of whether the plants were presented singly or mixed together. Significantly more females than males fed on plants, with the exception of P. hysterophorus L., one of the plants most frequently fed on. For most plant species (ten of 13), GC profiles indicated that An. gambiae obtained sugars primarily from flowers. The exceptions were P. hysterophorus L., Lantana camara L. and R. communis L., on which An. gambiae fed more often from leaves and stems than from flowers. PMID:17373953

  3. Kdr-based insecticide resistance in Anopheles gambiae s.s populations in

    PubMed Central

    2011-01-01

    Background The spread of insecticide resistance in the malaria mosquito, Anopheles gambiae is a serious threat for current vector control strategies which rely on the use of insecticides. Two mutations at position 1014 of the S6 transmembrane segment of domain II in the voltage gated sodium channel, known as kdr (knockdown resistance) mutations leading to a change of a Leucine to a Phenylalanine (L1014F) or to a Serine (L1014S) confer resistance to DDT and pyrethroid insecticides in the insect. This paper presents the current distribution of the kdr alleles in wild Anopheles gambiae populations in Cameroon. Results A total of 1,405 anopheline mosquitoes were collected from 21 localities throughout Cameroon and identified as An. gambiae (N = 1,248; 88.8%), An. arabiensis (N = 120; 8.5%) and An. melas (N = 37; 2.6%). Both kdr alleles 1014F and 1014S were identified in the M and S molecular forms of An. gambiae s.s. The frequency of the 1014F allele ranged from 1.7 to 18% in the M-form, and from 2 to 90% in the S-form. The 1014S allele ranged from 3-15% in the S-form and in the M-form its value was below 3%. Some specimens were found to carry both resistant kdr alleles. Conclusion This study provides an updated distribution map of the kdr alleles in wild An. gambiae populations in Cameroon. The co-occurrence of both alleles in malaria mosquito vectors in diverse ecological zones of the country may be critical for the planning and implementation of malaria vector control interventions based on IRS and ITNs, as currently ongoing in Cameroon. PMID:22035176

  4. Serological reactivity to Borrelia burgdorferi sensu lato in dogs and horses from distinct areas in Romania.

    PubMed

    Kiss, Timea; Cadar, Daniel; Krupaci, Alexandra Florina; Bordeanu, Armela; Brudaşcă, Gheorghe Florinel; Mihalca, Andrei Daniel; Mircean, Viorica; Gliga, Lucia; Dumitrache, Mirabela Oana; Spînu, Marina

    2011-09-01

    Lyme disease is a perfect model of the complex relationship between host, vector, and the vector-borne bacteria. Both dogs and horses in Romania are exposed to infection. The aim of the present study was to assess the seroreactivity against Borrelia burgdorferi sensu lato in dogs and horses from different regions of Romania. 276 samples from dogs and 260 samples from horses located in different regions of Romania were analyzed by ELISA and IFA, respectively. The effect of several factors potentially affecting seroreactivity (location, age, gender, occupation, and vector exposition risk) was evaluated using Fisher's exact test (R 2.12.0). The overall prevalence of anti-Borrelia antibodies was 6.52% (18/276) in dogs, with a significantly higher positivity (46.15%, 6/13, p = 0.0005) recorded in a midcountry region. Seroreactivity was correlated with occupation, with working dogs being more exposed. The results may indicate that Lyme borreliosis foci are restricted to small areas, but further studies on Borrelia prevalence in tick populations are needed to confirm this hypothesis. In horses, a global seroprevalence of 11.92% (31/260) was observed. No correlations were found between positive results and age, sex, county, or occupation. This is the first serological survey on antibodies to B. burgdorferi sensu lato in Romanian dogs and horses. PMID:21612524

  5. First isolation and cultivation of Borrelia burgdorferi sensu lato from Missouri.

    PubMed

    Oliver, J H; Kollars, T M; Chandler, F W; James, A M; Masters, E J; Lane, R S; Huey, L O

    1998-01-01

    Five Borrelia burgdorferi sensu lato isolates from Missouri are described. This represents the first report and characterization of such isolates from that state. The isolates were obtained from either Ixodes dentatus or Amblyomma americanum ticks that had been feeding on cottontail rabbits (Sylvilagus floridanus) from a farm in Bollinger County, Mo., where a human case of Lyme disease had been reported. All isolates were screened immunologically by indirect immunofluorescence by using monoclonal antibodies to B. burgdorferi-specific outer surface protein A (OspA) (antibodies H3TS and H5332), B. burgdorferi-specific OspB (antibody H6831), Borrelia (genus)-specific antiflagellin (antibody H9724), and Borrelia hermsii-specific antibody (antibody H9826). Analysis of the isolates also involved a comparison of their protein profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Finally, the isolates were analyzed by PCR with six pairs of primers known to amplify selected DNA target sequences specifically found in the reference strain B. burgdorferi B-31. Although some genetic variability was detected among the five isolates as well as between them and the B-31 strain, enough similarities were found to classify them as B. burgdorferi sensu lato. PMID:9431909

  6. The knowledge, attitudes and practices of wintersun vacationers to the Gambia toward prevention of malaria: is it really that bad?

    PubMed Central

    2014-01-01

    Background Each year clusters of imported malaria cases are observed in Dutch wintersun vacationers returning from The Gambia. To gain more insight in the travel health preparation and awareness of these travellers, the knowledge, attitudes and practices (KAP) of this travel group was studied by analysing the data of the Continuous Dutch Schiphol Airport Survey. Methods In the years 2002 to 2009 a questionnaire-based survey was conducted at the Dutch Schiphol Airport with the aim to study the KAP, i.e. accuracy of risk perception (“knowledge”), intended risk-avoiding behaviour (“attitude”) and use of personal protective measures and malaria chemoprophylaxis (“practice”) toward prevention malaria in travellers to The Gambia. Travellers to other high-risk destinations served as controls. Results The KAP of travellers to The Gambia toward prevention of malaria was significantly better than that observed in other travellers. Trend analyses indicated that attitude improved over time in both groups but knowledge did not change. Only in travellers to high-risk countries other than The Gambia significant increases in protection rates were observed over time. Conclusions The KAP of travellers to The Gambia toward prevention of malaria was better than that observed in travellers to destinations other than The Gambia. Trend analyses revealed a significant improvement of intended risk avoiding behaviour but not in protection rates or risk perception. PMID:24581328

  7. Environmental factors associated with the distribution of Anopheles gambiae s.s in Ghana; an important vector of lymphatic filariasis and malaria.

    PubMed

    de Souza, Dziedzom; Kelly-Hope, Louise; Lawson, Bernard; Wilson, Michael; Boakye, Daniel

    2010-01-01

    Anopheles gambiae s.s mosquitoes are important vectors of lymphatic filariasis (LF) and malaria in Ghana. To better understand their ecological aspects and influence on disease transmission, we examined the spatial distribution of the An. gambiae (M and S) molecular forms and associated environmental factors, and determined their relationship with disease prevalence. Published and current data available on the An. gambiae species in Ghana were collected in a database for analysis, and the study sites were georeferenced and mapped. Using the An. gambiae s.s sites, environmental data were derived from climate, vegetation and remote-sensed satellite sources, and disease prevalence data from existing LF and malaria maps in the literature. The data showed that An. gambiae M and S forms were sympatric in most locations. However, the S form predominated in the central region, while the M form predominated in the northern and coastal savanna regions. Bivariate and multiple regression analyses identified temperature as a key factor distinguishing their distributions. An. gambiae M was significantly correlated with LF, and 2.5 to 3 times more prevalent in the high LF zone than low to medium zones. There were no significant associations between high prevalence An. gambiae s.s locations and malaria. The distribution of the An. gambiae M and S forms and the diseases they transmit in Ghana appear to be distinct, driven by different environmental factors. This study provides useful baseline information for disease control, and future work on the An. gambiae s.s in Ghana. PMID:20360950

  8. Predatory capacity of a shorefly, Ochthera chalybescens, on malaria vectors

    PubMed Central

    Minakawa, Noboru; Futami, Kyoko; Sonye, George; Akweywa, Peter; Kaneko, Satoshi

    2007-01-01

    Background Since Ochthera chalybescens had been reported to prey on African malaria vectors, the predatory capacity of adults of this species on Anopheles gambiae sensu stricto was explored. Method Predatory capacity of this fly on A. gambiae s.s. was tested at all developmental stages, including the adult stage in the laboratory setting. Effects of water depth on its predatory capacity were also examined. Results This study revealed that O. chalybescens preyed on mosquitoes at all life stages except eggs. It was able to prey on an average of 9.8 to 18.8 mosquito larvae in 24 hrs. Mosquito larva size and water depth did not affect predatory capacity. However, the predacious fly preyed on significantly more 2nd-instar larvae than on pupae when larvae and pupae were both available. Conclusion Ochthera chalybescens is, by all indications, an important predator of African malaria vectors. PMID:17683604

  9. Draft Genome Sequences of Human Pathogenic Fungus Geomyces pannorum Sensu Lato and Bat White Nose Syndrome Pathogen Geomyces (Pseudogymnoascus) destructans.

    PubMed

    Chibucos, Marcus C; Crabtree, Jonathan; Nagaraj, Sushma; Chaturvedi, Sudha; Chaturvedi, Vishnu

    2013-01-01

    We report the draft genome sequences of Geomyces pannorum sensu lato and Geomyces (Pseudogymnoascus) destructans. G. pannorum has a larger proteome than G. destructans, containing more proteins with ascribed enzymatic functions. This dichotomy in the genomes of related psychrophilic fungi is a valuable target for defining their distinct saprobic and pathogenic attributes. PMID:24356829

  10. Revision of New World Chaenusa Haliday sensu lato (Hymenoptera: Braconidae: Alysiinae), with new species, synonymies, hosts, and distribution records

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The New World species of Chaenusa Haliday sensu lato are revised. A diagnosis is provided for Chaenusa s.l. Four new species from North America, Chaenusa trumani, Chaenusa virgili, Chaenusa whartoni, and Chaenusa woolleyi, and two new species from South America, Chaenusa hirsutissima and Chaenusa ir...

  11. Draft Genome Sequences of Human Pathogenic Fungus Geomyces pannorum Sensu Lato and Bat White Nose Syndrome Pathogen Geomyces (Pseudogymnoascus) destructans

    PubMed Central

    Crabtree, Jonathan; Nagaraj, Sushma; Chaturvedi, Sudha

    2013-01-01

    We report the draft genome sequences of Geomyces pannorum sensu lato and Geomyces (Pseudogymnoascus) destructans. G. pannorum has a larger proteome than G. destructans, containing more proteins with ascribed enzymatic functions. This dichotomy in the genomes of related psychrophilic fungi is a valuable target for defining their distinct saprobic and pathogenic attributes. PMID:24356829

  12. Genetic structure of Colletotrichum gloeosporioides sensu lato isolates infecting papaya inferred by multilocus ISSR markers.

    PubMed

    Rampersad, Sephra N

    2013-02-01

    Colletotrichum gloeosporioides sensu lato is widely distributed throughout temperate and tropical regions and causes anthracnose disease in numerous plant species. Development of effective disease management strategies is dependent on, among other factors, an understanding of pathogen genetic diversity and population stratification at the intraspecific level. For 132 isolates of C. gloeosporioides sensu lato collected from papaya in Trinidad, inter-simple-sequence repeat-polymerase chain reaction (ISSR-PCR) generated 121 polymorphic loci from five ISSR primers selected from an initial screen of 22 ISSR primers. The mean percentage of polymorphic loci was 99.18%. Bayesian cluster analysis inferred three genetic subpopulations, where group 1 consisted exclusively of isolates collected in the southern part of Trinidad whereas groups 2 and 3, although genetically distinct, were mixtures of isolates collected from both the northern and southern parts of Trinidad. Principal coordinates analysis and unweighted pair-group method with arithmetic mean phylogeny were concordant with Bayesian cluster analysis and supported subdivision into the three subpopulations. Overall, the total mean gene diversity was 0.279, the mean within-population gene diversity was 0.2161, and genetic differentiation for the Trinidad population was 0.225. Regionally, northern isolates had a lower gene diversity compared with southern isolates. Nei's gene diversity was highest for group 1 (h = 0.231), followed by group 2 (h = 0.215) and group 3 (h = 0.202). Genotypic diversity was at or near maximum for all three subpopulations after clone correction. Pairwise estimates of differentiation indicated high and significant genetic differentiation among the inferred subpopulations (Weir's θ of 0.212 to 0.325). Pairwise comparisons among subpopulations suggested restricted gene flow between groups 1 and 2 and groups 1 and 3 but not between groups 2 and 3. The null hypothesis of random mating was rejected

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

    PubMed Central

    2012-01-01

    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 between rounds of testing, and

  14. A taxonomic review of the Neoserica (sensu lato) septemlamellata group (Coleoptera, Scarabaeidae, Sericini)

    PubMed Central

    Ahrens, Dirk; Liu, Wan-Gang; Fabrizi, Silvia; Bai, Ming; Yang, Xing-Ke

    2014-01-01

    Abstract In the present paper the species belonging to the Neoserica (sensu lato) septemlamellata group, that included so far only four known species, are revised. Here we describe eleven new species originating mainly from Indochina and Southern China: N. daweishanica sp. n., N. gaoligongshanica sp. n., N. guangpingensis sp. n., N. igori sp. n., N. jiulongensis sp. n., N. plurilamellata sp. n., N. weishanica sp. n., N. yanzigouensis sp. n. (China) N. sapaensis sp. n. (China, Vietnam), N. bansongchana sp. n., N. takakuwai sp. n. (Laos). The lectotypes of Neoserica septemlamellata Brenske, 1898 and N. septemfoliata Moser, 1915 are designated. Keys to the species and species groups are given, the genitalia of all species and their habitus are illustrated and distribution maps are included. PMID:24843263

  15. Helicobacter heilmannii sensu lato: An overview of the infection in humans

    PubMed Central

    Bento-Miranda, Mario; Figueiredo, Ceu

    2014-01-01

    Helicobacter heilmannii sensu lato (H. heilmannii s.l.) is a group of gastric non-Helicobacter pylori Helicobacter species that are morphologically indistinguishable from each other. H. heilmannii s.l. infect the stomach of several animals and may have zoonotic potential. Although the prevalence of these infections in humans is low, they are associated with gastric pathology, including mucosa-associated lymphoid tissue lymphoma, making them a significant health issue. Here, the taxonomy, epidemiology, microbiology, diagnosis, and treatment of these infections will be reviewed. The gastric pathology associated with H. heilmannii s.l. infections in humans will also be addressed. Finally, the features of the complete bacterial genomes available and studies on species-specific pathogenesis will be reviewed. The understanding of the mechanisms that underlie gastric disease development mediated by the different bacterial species that constitute H. heilmannii s.l. is essential for developing strategies for prevention and treatment of these infections. PMID:25548476

  16. Antimicrobial activity of Stomoxys calcitrans against Beauveria bassiana sensu lato isolates.

    PubMed

    Moraes, Ana Paula Rodrigues de; Salles, Cristiane Martins Cardoso de; Bittencourt, Vânia Rita Elias Pinheiro; Bittencourt, Avelino José

    2015-01-01

    This study had the aims of evaluating the antimicrobial characteristics of Stomoxys calcitrans (Diptera: Muscidae) larvae against the fungal isolates CG138, CG228 and ESALQ986 of Beauveria bassiana sensu lato (Balsamo-Crivelli) Vuillemin, 1912 (Hypocreales: Cordycipitaceae). S. calcitrans eggs, larvae and pupae were exposed to these same isolates. Statistical analysis showed that the immature stages of S. calcitrans were not susceptible to the fungal isolates used, regardless of the exposure method. Diffusion test on solid culture medium reveled that macerated S. calcitrans larvae exposed to isolate CG138 reduced CG138 fungal development. The analysis of the chromatographic profiles indicated that the macerate or mucus of larvae of the control group and the groups exposed to the isolate CG138 presented different profiles. Reduced development of the isolate CG138 on the larvae cuticle was observed by means of scanning electron microscopy. PMID:26444064

  17. Molecular, biological, and morphometric comparisons between different geographical populations of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae).

    PubMed

    Sanches, Gustavo S; Évora, Patrícia M; Mangold, Atílio J; Jittapalapong, Sattaporn; Rodriguez-Mallon, Alina; Guzmán, Pedro E E; Bechara, Gervásio H; Camargo-Mathias, Maria I

    2016-01-15

    In this study, different geographical populations of Rhipicephalus sanguineus sensu lato were compared by molecular, biological, and morphometric methods. Phylogenetic trees were constructed using 12S and 16S rDNA sequences and showed two distinct clades: one composed of ticks from Brazil (Jaboticabal, SP), Cuba (Havana) Thailand (Bangkok) and the so-called "tropical strain" ticks. The second clade was composed of ticks from Spain (Zaragoza), Argentina (Rafaela, Santa Fe) and the so-called "temperate strain" ticks. Morphometric analysis showed good separation between females of the two clades and within the temperate clade. Males also exhibited separation between the two clades, but with some overlap. Multiple biological parameters revealed differences between the two clades, especially the weight of the engorged female. These results confirm the existence of at least two species under the name "R. sanguineus". PMID:26790741

  18. An Invasive Mammal (the Gray Squirrel, Sciurus carolinensis) Commonly Hosts Diverse and Atypical Genotypes of the Zoonotic Pathogen Borrelia burgdorferi Sensu Lato

    PubMed Central

    Magierecka, Agnieszka; Gilbert, Lucy; Edoff, Alissa; Brereton, Amelia; Kilbride, Elizabeth; Denwood, Matt; Birtles, Richard; Biek, Roman

    2015-01-01

    Invasive vertebrate species can act as hosts for endemic pathogens and may alter pathogen community composition and dynamics. For the zoonotic pathogen Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, recent work shows invasive rodent species can be of high epidemiological importance and may support host-specific strains. This study examined the role of gray squirrels (Sciurus carolinensis) (n = 679), an invasive species in the United Kingdom, as B. burgdorferi sensu lato hosts. We found that gray squirrels were frequently infested with Ixodes ricinus, the main vector of B. burgdorferi sensu lato in the United Kingdom, and 11.9% were infected with B. burgdorferi sensu lato. All four genospecies that occur in the United Kingdom were detected in gray squirrels, and unexpectedly, the bird-associated genospecies Borrelia garinii was most common. The second most frequent infection was with Borrelia afzelii. Genotyping of B. garinii and B. afzelii produced no evidence for strains associated with gray squirrels. Generalized linear mixed models (GLMM) identified tick infestation and date of capture as significant factors associated with B. burgdorferi sensu lato infection in gray squirrels, with infection elevated in early summer in squirrels infested with ticks. Invasive gray squirrels appear to become infected with locally circulating strains of B. burgdorferi sensu lato, and further studies are required to determine their role in community disease dynamics. Our findings highlight the fact that the role of introduced host species in B. burgdorferi sensu lato epidemiology can be highly variable and thus difficult to predict. PMID:25888168

  19. Differential Attraction of Malaria Mosquitoes to Volatile Blends Produced by Human Skin Bacteria

    PubMed Central

    Verhulst, Niels O.; Andriessen, Rob; Groenhagen, Ulrike; Bukovinszkiné Kiss, Gabriella; Schulz, Stefan; Takken, Willem; van Loon, Joop J. A.; Schraa, Gosse; Smallegange, Renate C.

    2010-01-01

    The malaria mosquito Anopheles gambiae sensu stricto is mainly guided by human odour components to find its blood host. Skin bacteria play an important role in the production of human body odour and when grown in vitro, skin bacteria produce volatiles that are attractive to A. gambiae. The role of single skin bacterial species in the production of volatiles that mediate the host-seeking behaviour of mosquitoes has remained largely unknown and is the subject of the present study. Headspace samples were taken to identify volatiles that mediate this behaviour. These volatiles could be used as mosquito attractants or repellents. Five commonly occurring species of skin bacteria were tested in an olfactometer for the production of volatiles that attract A. gambiae. Odour blends produced by some bacterial species were more attractive than blends produced by other species. In contrast to odours from the other bacterial species tested, odours produced by Pseudomonas aeruginosa were not attractive to A. gambiae. Headspace analysis of bacterial volatiles in combination with behavioural assays led to the identification of six compounds that elicited a behavioural effect in A. gambiae. Our results provide, to our knowledge, the first evidence for a role of selected bacterial species, common on the human skin, in determining the attractiveness of humans to malaria mosquitoes. This information will be used in the further development of a blend of semiochemicals for the manipulation of mosquito behaviour. PMID:21209854

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

    PubMed Central

    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

  1. Energy metabolism affects susceptibility of A. gambiae mosquitoes to Plasmodium infection

    PubMed Central

    Oliveira, Jose Henrique M.; Gonçalves, Renata L.S.; Oliveira, Giselle A.; Oliveira, Pedro L.; Oliveira, Marcus F.; Barillas-Mury, Carolina

    2011-01-01

    Previous studies showed that A. gambiae L35 females, which are refractory (R) to Plasmodium infection, express higher levels of genes involved in redox-metabolism and mitochondrial respiration than susceptible (S) G3 females. Our studies revealed that R females have reduced longevity, faster utilization of lipid reserves, impaired mitochondrial State-3 respiration, increased rate of mitochondrial electron leak and higher expression levels of several glycolytic enzyme genes. Furthermore, when State-3 respiration was reduced in S females by silencing expression of the adenine nucleotide translocator (ANT), hydrogen peroxide generation was higher and the mRNA levels of lactate dehydrogenase increased in the midgut, while the prevalence and intensity of P. berghei infection were significantly reduced. We conclude that there are broad metabolic differences between R and S An. gambiae mosquitoes that influence their susceptibility to Plasmodium infection. PMID:21320598

  2. Inversions and Gene Order Shuffling in Anopheles gambiae and A. funestus

    NASA Astrophysics Data System (ADS)

    Sharakhov, Igor V.; Serazin, Andrew C.; Grushko, Olga G.; Dana, Ali; Lobo, Neil; Hillenmeyer, Maureen E.; Westerman, Richard; Romero-Severson, Jeanne; Costantini, Carlo; Sagnon, N'Fale; Collins, Frank H.; Besansky, Nora J.

    2002-10-01

    In tropical Africa, Anopheles funestus is one of the three most important malaria vectors. We physically mapped 157 A. funestus complementary DNAs (cDNAs) to the polytene chromosomes of this species. Sequences of the cDNAs were mapped in silico to the A. gambiae genome as part of a comparative genomic study of synteny, gene order, and sequence conservation between A. funestus and A. gambiae. These species are in the same subgenus and diverged about as recently as humans and chimpanzees. Despite nearly perfect preservation of synteny, we found substantial shuffling of gene order along corresponding chromosome arms. Since the divergence of these species, at least 70 chromosomal inversions have been fixed, the highest rate of rearrangement of any eukaryote studied to date. The high incidence of paracentric inversions and limited colinearity suggests that locating genes in one anopheline species based on gene order in another may be limited to closely related taxa.

  3. Characterization of inhibitors and substrates of Anopheles gambiae CYP6Z2.

    PubMed

    McLaughlin, L A; Niazi, U; Bibby, J; David, J-P; Vontas, J; Hemingway, J; Ranson, H; Sutcliffe, M J; Paine, M J I

    2008-04-01

    Three CYP6Z genes are linked to a major pyrethroid resistance locus in the mosquito Anopheles gambiae. We have expressed CYP6Z2 in Escherichia coli and produced a structural model in order to examine its role in detoxification. E. coli membranes co-expressing CYP6Z2 and An. gambiae P450 reductase (AgCPR) catalysed the dealkylation of benzyloxyresorufin with kinetic parameters K(m) = 0.13 microM; K(cat) = 1.5 min(-1). The IC(50) values of a wide range of compounds were measured. Pyrethroids cypermethrin and permethrin produced low IC(50) values, but were not metabolized. Plant flavanoids were the most potent inhibitors. Several compounds were shown to be substrates, suggesting that CYP6Z2 has broad substrate specificity and plays an important chemo-protective role during the herbivorous phase of the life-cycle. PMID:18353102

  4. Cloning and analysis of a cecropin gene from the malaria vector mosquito, Anopheles gambiae.

    PubMed

    Vizioli, J; Bulet, P; Charlet, M; Lowenberger, C; Blass, C; Müller, H M; Dimopoulos, G; Hoffmann, J; Kafatos, F C; Richman, A

    2000-02-01

    Parasites of the genus Plasmodium are transmitted to mammalian hosts by anopheline mosquitoes. Within the insect vector, parasite growth and development are potentially limited by antimicrobial defence molecules. Here, we describe the isolation of cDNA and genomic clones encoding a cecropin antibacterial peptide from the malaria vector mosquito Anopheles gambiae. The locus was mapped to polytene division 1C of the X chromosome. Cecropin RNA was induced by infection with bacteria and Plasmodium. RNA levels varied in different body parts of the adult mosquito. During development, cecropin expression was limited to the early pupal stage. The peptide was purified from both adult mosquitoes and cell culture supernatants. Anopheles gambiae synthetic cecropins displayed activity against Gram-negative and Gram-positive bacteria, filamentous fungi and yeasts. PMID:10672074

  5. Integrated genetic map of Anopheles gambiae: use of RAPD polymorphisms for genetic, cytogenetic and STS landmarks.

    PubMed

    Dimopoulos, G; Zheng, L; Kumar, V; della Torre, A; Kafatos, F C; Louis, C

    1996-06-01

    Randomly amplified polymorphic DNA (RAPD) markers have been integrated in the genetic and cytogenetic maps of the malaria vector mosquito, Anopheles gambiae. Fifteen of these markers were mapped by recombination, relative to microsatellite markers that had been mapped previously. Thirty-four gel-purified RAPD bands were cloned and sequenced, generating sequence tagged sites (STSs) that can be used as entry points to the A. gambiae genome. Thirty one of these STSs were localized on nurse cell polytene chromosomes through their unique hybridization signal in in situ hybridization experiments. Five STSs map close to the breakpoints of polymorphic inversions, which are notable features of the Anopheles genome. The usefulness and limitations of this integrated mosquito map are discussed. PMID:8725241

  6. Energy metabolism affects susceptibility of Anopheles gambiae mosquitoes to Plasmodium infection.

    PubMed

    Oliveira, Jose Henrique M; Gonçalves, Renata L S; Oliveira, Giselle A; Oliveira, Pedro L; Oliveira, Marcus F; Barillas-Mury, Carolina

    2011-06-01

    Previous studies showed that Anopheles gambiae L3-5 females, which are refractory (R) to Plasmodium infection, express higher levels of genes involved in redox-metabolism and mitochondrial respiration than susceptible (S) G3 females. Our studies revealed that R females have reduced longevity, faster utilization of lipid reserves, impaired mitochondrial state-3 respiration, increased rate of mitochondrial electron leak and higher expression levels of several glycolytic enzyme genes. Furthermore, when state-3 respiration was reduced in S females by silencing expression of the adenine nucleotide translocator (ANT), hydrogen peroxide generation was higher and the mRNA levels of lactate dehydrogenase increased in the midgut, while the prevalence and intensity of Plasmodium berghei infection were significantly reduced. We conclude that there are broad metabolic differences between R and S An. gambiae mosquitoes that influence their susceptibility to Plasmodium infection. PMID:21320598

  7. Childhood feeding practices and their effects on nutrition in a rural area of The Gambia.

    PubMed

    Whitworth, J A; Cross, I B; Morgan, D

    1987-10-01

    We have studied the nutritional status of 118 children of the Serahuli tribe aged 0-5 years from Badjakunda, a village in North Bank, Upper River Division (URD) of The Gambia. Throughout the 9 month study period malnutrition was identified in a larger proportion of children than in similar recent studies elsewhere in The Gambia. We have found a relationship in villages in North Bank URD between the percentage of Serahulis in the population and the percentage of children with malnutrition. Serahulis in Badjakunda generally do not introduce weaning foods until the child is aged 1 year, while Mandinkas in the same area usually start such foods before their children are 6 months old. Children aged between 6 months and 2 years were at particular risk of malnutrition, this may be attributable to the feeding practices of Serahulis. PMID:3669123

  8. Mixed populations of Bulinus senegalensis (Muller) and Bulinus forskali (Ehrenburg) (Mollusca: Planorbidae) in The Gambia.

    PubMed

    Goll, P H

    1981-01-01

    A brief survey of alluvial pools and irrigated ricefields in The Gambia shows that the distribution of Bulinus senegalensis is not confined to laterite pools and is similar to that in neighbouring Senegal. B. senegalensis was found in every site at least once, alone or with B. forskali. The proportion of the two species varies during the season and from year to year. It is no longer necessary to consider B. forskali as a natural host of S. haematobium. PMID:7324134

  9. Survival of female Anopheles gambiae Giles through a 9-month dry season in Sudan*

    PubMed Central

    Omer, Salah M.; Cloudsley-Thompson, J. L.

    1970-01-01

    The dry-season biology of a member of the Anopheles gambiae complex (probably species B) was studied in 2 areas in the Khartoum region of Sudan. It was found that in the valley of the White Nile the species maintained itself by low-level breeding, as shown by the continuing presence of larvae, male mosquitos and parous females through the dry months (9 months in the year). In the scattered villages of arid areas situated more than 20 km from the Nile Valley, on the other hand, regular sampling through the cool dry and hot dry months of the year failed to detect any An. gambiae except nulliparous females. These were found in occupied huts, deserted huts, dry wells and animal burrows. The great majority of 213 females collected in the 11 dry months between November 1966 and December 1967 had fresh or older blood-meals but the abdomen was never found fully distended in the dry season. Examination of the ovaries showed that they did not develop beyond Christophers' stage II in the period from November to February, stage III in March and April, or beyond stage IV in May. But, in June and July stage IV and V ovaries predominated and few specimens remained in stage late-II. It is inferred from these observations that the local population of An. gambiae is highly adapted to survive in the adult stage through the severe drought and heat of the arid zone of Sudan. Some feeding activity continues but ovarian development is extremely retarded, and only one batch of eggs matures during the whole 9-month period. Evidence collected in the Nile Valley indicated that female An. gambiae in that area were not subjected to similar retardation of the ovarian cycle; in fact, clear evidence was obtained there of continuous year-round breeding by the mosquito. PMID:5310144

  10. Remote sensing and environment in the study of the malaria vector Anopheles gambiae in Mali

    NASA Astrophysics Data System (ADS)

    Rian, Sigrid Katrine Eivindsdatter

    The malaria mosquito Anopheles gambiae is the most important vector for the most devastating form of human malaria, the parasite Plasmodium falciparum. In-depth knowledge of the vector's history and environmental preferences is essential in the pursuit of new malaria mitigation strategies. Research was conducted in Mali across a range of habitats occupied by the vector, focusing on three identified chromosomal forms in the mosquito complex. The development of a 500-m landcover classification map was carried out using MODIS satellite imagery and extensive ground survey. The resulting product has the highest resolution and is the most up-to-date and most extensively ground-surveyed among land-cover maps for the study region. The new landcover classification product is a useful tool in the mapping of the varying ecological preferences of the different An. gambiae chromosomal forms. Climate and vegetation characteristics and their relationship to chromosomal forms were investigated further along a Southwest-Northeast moisture gradient in Mali. This research demonstrates particular ecological preferences of each chromosomal form, and gives a detailed examination of particular vegetation structural and climatological patterns across the study region. A key issue in current research into the population structure of An. gambiae is speciation and evolution in the complex, as an understanding of the mechanisms of change can help in the development of new mitigation strategies. A historical review of the paleoecology, archaeology, and other historical sources intended to shed light on the evolutionary history of the vector is presented. The generally held assumption that the current breed of An. gambiae emerged in the rainforest is called into question and discussed within the framework of paleoenvironment and human expansions in sub-Saharan West Africa.

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

    PubMed

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

    2015-11-01

    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. PMID:26615027

  12. Beta-integrin of Anopheles gambiae: mRNA cloning and analysis of structure and expression.

    PubMed

    Mahairaki, V; Lycett, G; Blass, C; Louis, C

    2001-06-01

    We have isolated an mRNA encoding a beta integrin subunit of the malaria mosquito Anopheles gambiae. Our analysis predicts a protein that is very similar to betaPS, the fruitfly orthologue. The gene is expressed during all developmental stages and it is found in all body parts, including the midgut. Finally, the expression of the gene does not seem to be modulated during blood meals, except for a substantial increase 48 h posthaematophagy, when digestion is nearly complete. PMID:11437913

  13. Characterization of the target of ivermectin, the glutamate-gated chloride channel, from Anopheles gambiae

    PubMed Central

    Meyers, Jacob I.; Gray, Meg; Kuklinski, Wojtek; Johnson, Lucas B.; Snow, Christopher D.; Black, William C.; Partin, Kathryn M.; Foy, Brian D.

    2015-01-01

    ABSTRACT The use of insecticide-treated nets and indoor residual insecticides targeting adult mosquito vectors is a key element in malaria control programs. However, mosquito resistance to the insecticides used in these applications threatens malaria control efforts. Recently, the mass drug administration of ivermectin (IVM) has been shown to kill Anopheles gambiae mosquitoes and disrupt Plasmodium falciparum transmission in the field. We cloned the molecular target of IVM from A. gambiae, the glutamate-gated chloride channel (AgGluCl), and characterized its transcriptional patterns, protein expression and functional responses to glutamate and IVM. AgGluCl cloning revealed an unpredicted fourth splice isoform as well as a novel exon and splice site. The predicted gene products contained heterogeneity in the N-terminal extracellular domain and the intracellular loop region. Responses to glutamate and IVM were measured using two-electrode voltage clamp on Xenopus laevis oocytes expressing AgGluCl. IVM induced non-persistent currents in AgGluCl-a1 and did not potentiate glutamate responses. In contrast, AgGluCl-b was insensitive to IVM, suggesting that the AgGluCl gene could produce IVM-sensitive and -insensitive homomultimers from alternative splicing. AgGluCl isoform-specific transcripts were measured across tissues, ages, blood feeding status and sex, and were found to be differentially transcribed across these physiological variables. Lastly, we stained adult, female A. gambiae for GluCl expression. The channel was expressed in the antenna, Johnston's organ, supraesophageal ganglion and thoracic ganglia. In summary, we have characterized the first GluCl from a mosquito, A. gambiae, and described its unique activity and expression with respect to it as the target of the insecticide IVM. PMID:25994631

  14. Polymorphisms in Anopheles gambiae Immune Genes Associated with Natural Resistance to Plasmodium falciparum

    PubMed Central

    Harris, Caroline; Lambrechts, Louis; Rousset, François; Abate, Luc; Nsango, Sandrine E.; Fontenille, Didier; Morlais, Isabelle; Cohuet, Anna

    2010-01-01

    Many genes involved in the immune response of Anopheles gambiae, the main malaria vector in Africa, have been identified, but whether naturally occurring polymorphisms in these genes underlie variation in resistance to the human malaria parasite, Plasmodium falciparum, is currently unknown. Here we carried out a candidate gene association study to identify single nucleotide polymorphisms (SNPs) associated with natural resistance to P. falciparum. A. gambiae M form mosquitoes from Cameroon were experimentally challenged with three local wild P. falciparum isolates. Statistical associations were assessed between 157 SNPs selected from a set of 67 A. gambiae immune-related genes and the level of infection. Isolate-specific associations were accounted for by including the effect of the isolate in the analysis. Five SNPs were significantly associated to the infection phenotype, located within or upstream of AgMDL1, CEC1, Sp PPO activate, Sp SNAKElike, and TOLL6. Low overall and local linkage disequilibrium indicated high specificity in the loci found. Association between infection phenotype and two SNPs was isolate-specific, providing the first evidence of vector genotype by parasite isolate interactions at the molecular level. Four SNPs were associated to either oocyst presence or load, indicating that the genetic basis of infection prevalence and intensity may differ. The validity of the approach was verified by confirming the functional role of Sp SNAKElike in gene silencing assays. These results strongly support the role of genetic variation within or near these five A. gambiae immune genes, in concert with other genes, in natural resistance to P. falciparum. They emphasize the need to distinguish between infection prevalence and intensity and to account for the genetic specificity of vector-parasite interactions in dissecting the genetic basis of Anopheles resistance to human malaria. PMID:20862317

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

    PubMed Central

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

    2015-01-01

    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. PMID:26615027

  16. The English-Only Language Education Policy in the Gambia and Low Literacy Rates

    ERIC Educational Resources Information Center

    Igboanusi, Herbert

    2014-01-01

    The education policies of 1988-2003 and 2004-2015 in The Gambia make provisions for the use of the L1 or area languages to serve as the media of instruction from Grades 1 to 3 and as school subjects from Grade 4 onwards. However, the policy on the use of L1 for teaching has not been implemented and what is practised instead is the use of English…

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

    PubMed Central

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

    2014-01-01

    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. PMID:24875042

  18. Role of fish as predators of mosquito larvae on the floodplain of the Gambia River.

    PubMed

    Louca, Vasilis; Lucas, Martyn C; Green, Clare; Majambere, Silas; Fillinger, Ulrike; Lindsay, Steve W

    2009-05-01

    We examined the potential of using native fish species in regulating mosquitoes in the floodplain of the Gambia River, the major source of mosquitoes in rural parts of The Gambia. Fishes and mosquito larvae were sampled along two 2.3-km-long transects, from the landward edge of the floodplain to the river from May to November 2005 to 2007. A semifield trial was used to test the predatory capacity of fish on mosquito larvae and the influence of fish chemical cues on oviposition. In the field, there was less chance of finding culicine larvae where Tilapia guineensis, the most common floodplain fish, were present; however, the presence of anophelines was not related to the presence or absence of any fish species. In semifield trials, both T. guineensis and Epiplatys spilargyreius were effective predators, removing all late-stage culicine and anopheline larvae within 1 d. Fewer culicines oviposited in sites with fish, suggesting that ovipositing culicine females avoid water with fish. In contrast, oviposition by anophelines was unaffected by fish. Our studies show that T. guineensis is a potential candidate for controlling mosquitoes in The Gambia. PMID:19496426

  19. A Functional Role for Anopheles gambiae Arrestin1 in Olfactory Signal Transduction

    PubMed Central

    Walker, William B.; Smith, Elaine M.; Jan, Taha; Zwiebel, L.J.

    2008-01-01

    Insect sensory arrestins act to desensitize visual and olfactory signal transduction pathways, as evidenced by the phenotypic effects of mutations in the genes encoding both Arr1 and Arr2 in Drosophila melanogaster. To assess whether such arrestins play similar roles in other, more medically relevant dipterans, we examined the ability of Anopheles gambiae sensory arrestin homologues AgArr1 and AgArr2 to rescue phenotypes associated with an olfactory deficit observed in D. melanogaster arrestin mutants. Of these, only AgArr1 facilitated significant phenotypic rescue of the corresponding Drosophila arr mutant olfactory phenotype, consistent with the view that functional orthology is shared by these Arr1 homologues. These results represent the first step in the functional characterization of AgArr1, which is highly expressed in olfactory appendages of An. gambiae in which it is likely to play an essential role in olfactory signal transduction. In addition to providing insight into the common elements of the peripheral olfactory system of dipterans, this work validates the importance of AgArr1 as a potential target for novel anti-malaria strategies that focus on olfactory-based behaviors in An. gambiae. PMID:18328499

  20. The molecular and cellular basis of olfactory-driven behavior in Anopheles gambiae larvae

    PubMed Central

    Xia, Yuanfeng; Wang, Guirong; Buscariollo, Daniela; Pitts, R. Jason; Wenger, Heidi; Zwiebel, Laurence J.

    2008-01-01

    The mosquito Anopheles gambiae is the principal Afrotropical vector for human malaria. A central component of its vectorial capacity is the ability to maintain sufficient populations of adults. During both adult and preadult (larval) stages, the mosquitoes depend on the ability to recognize and respond to chemical cues that mediate feeding and survival. In this study, we used a behavioral assay to identify a range of odorant-specific responses of An. gambiae larvae that are dependent on the integrity of the larval antennae. Parallel molecular analyses have identified a subset of the An. gambiae odorant receptors (AgOrs) that are localized to discrete neurons within the larval antennae and facilitate odor-evoked responses in Xenopus oocytes that are consistent with the larval behavioral spectrum. These studies shed light on chemosensory-driven behaviors and represent molecular and cellular characterization of olfactory processes in mosquito larvae. These advances may ultimately enhance the development of vector control strategies, targeting olfactory pathways in larval-stage mosquitoes to reduce the catastrophic effects of malaria and other diseases. PMID:18427108

  1. Identification and Characterization of Two Novel RNA Viruses from Anopheles gambiae Species Complex Mosquitoes

    PubMed Central

    Carissimo, Guillaume; Eiglmeier, Karin; Reveillaud, Julie; Holm, Inge; Diallo, Mawlouth; Diallo, Diawo; Vantaux, Amélie; Kim, Saorin; Ménard, Didier; Siv, Sovannaroth; Belda, Eugeni; Bischoff, Emmanuel; Antoniewski, Christophe; Vernick, Kenneth D.

    2016-01-01

    Mosquitoes of the Anopheles gambiae complex display strong preference for human bloodmeals and are major malaria vectors in Africa. However, their interaction with viruses or role in arbovirus transmission during epidemics has been little examined, with the exception of O’nyong-nyong virus, closely related to Chikungunya virus. Deep-sequencing has revealed different RNA viruses in natural insect viromes, but none have been previously described in the Anopheles gambiae species complex. Here, we describe two novel insect RNA viruses, a Dicistrovirus and a Cypovirus, found in laboratory colonies of An. gambiae taxa using small-RNA deep sequencing. Sequence analysis was done with Metavisitor, an open-source bioinformatic pipeline for virus discovery and de novo genome assembly. Wild-collected Anopheles from Senegal and Cambodia were positive for the Dicistrovirus and Cypovirus, displaying high sequence identity to the laboratory-derived virus. Thus, the Dicistrovirus (Anopheles C virus, AnCV) and Cypovirus (Anopheles Cypovirus, AnCPV) are components of the natural virome of at least some anopheline species. Their possible influence on mosquito immunity or transmission of other pathogens is unknown. These natural viruses could be developed as models for the study of Anopheles-RNA virus interactions in low security laboratory settings, in an analogous manner to the use of rodent malaria parasites for studies of mosquito anti-parasite immunity. PMID:27138938

  2. The population genomics of trans-specific inversion polymorphisms in Anopheles gambiae.

    PubMed

    White, Bradley J; Cheng, Changde; Sangaré, Djibril; Lobo, Neil F; Collins, Frank H; Besansky, Nora J

    2009-09-01

    In the malaria mosquito Anopheles gambiae polymorphic chromosomal inversions may play an important role in adaptation to environmental variation. Recently, we used microarray-based divergence mapping combined with targeted resequencing to map nucleotide differentiation between alternative arrangements of the 2La inversion. Here, we applied the same technique to four different polymorphic inversions on the 2R chromosome of An. gambiae. Surprisingly, divergence was much lower between alternative arrangements for all 2R inversions when compared to the 2La inversion. For one of the rearrangements, 2Ru, we successfully mapped a very small region (approximately 100 kb) of elevated divergence. For the other three rearrangements, we did not identify any regions of significantly high divergence, despite ample independent evidence from natural populations of geographic clines and seasonal cycling, and stable heterotic polymorphisms in laboratory populations. If these inversions are the targets of selection as hypothesized, we suggest that divergence between rearrangements may have escaped detection due to retained ancestral polymorphism in the case of the youngest 2R rearrangements and to extensive gene flux in the older 2R inversion systems that segregate in both An. gambiae and its sibling species An. arabiensis. PMID:19581444

  3. Identification and Characterization of Two Novel RNA Viruses from Anopheles gambiae Species Complex Mosquitoes.

    PubMed

    Carissimo, Guillaume; Eiglmeier, Karin; Reveillaud, Julie; Holm, Inge; Diallo, Mawlouth; Diallo, Diawo; Vantaux, Amélie; Kim, Saorin; Ménard, Didier; Siv, Sovannaroth; Belda, Eugeni; Bischoff, Emmanuel; Antoniewski, Christophe; Vernick, Kenneth D

    2016-01-01

    Mosquitoes of the Anopheles gambiae complex display strong preference for human bloodmeals and are major malaria vectors in Africa. However, their interaction with viruses or role in arbovirus transmission during epidemics has been little examined, with the exception of O'nyong-nyong virus, closely related to Chikungunya virus. Deep-sequencing has revealed different RNA viruses in natural insect viromes, but none have been previously described in the Anopheles gambiae species complex. Here, we describe two novel insect RNA viruses, a Dicistrovirus and a Cypovirus, found in laboratory colonies of An. gambiae taxa using small-RNA deep sequencing. Sequence analysis was done with Metavisitor, an open-source bioinformatic pipeline for virus discovery and de novo genome assembly. Wild-collected Anopheles from Senegal and Cambodia were positive for the Dicistrovirus and Cypovirus, displaying high sequence identity to the laboratory-derived virus. Thus, the Dicistrovirus (Anopheles C virus, AnCV) and Cypovirus (Anopheles Cypovirus, AnCPV) are components of the natural virome of at least some anopheline species. Their possible influence on mosquito immunity or transmission of other pathogens is unknown. These natural viruses could be developed as models for the study of Anopheles-RNA virus interactions in low security laboratory settings, in an analogous manner to the use of rodent malaria parasites for studies of mosquito anti-parasite immunity. PMID:27138938

  4. Comparison of DNA probe and cytogenetic methods for identifying field collected Anopheles gambiae complex mosquitoes.

    PubMed

    Collins, F H; Petrarca, V; Mpofu, S; Brandling-Bennett, A D; Were, J B; Rasmussen, M O; Finnerty, V

    1988-12-01

    A recently developed DNA probe method was compared with the standard cytogenetic method for identifying the species of individual mosquitoes in the Anopheles gambiae complex. The complex consists of 6 morphologically indistinguishable sibling species that include the major African malaria vectors. Half-gravid, field collected mosquitoes were split into 2 portions: the abdomen was preserved for ovarian nurse cell cytotaxonomy and the head/thorax portion was desiccated for DNA extraction. Cytogenetic examination of the Kenya specimens showed 88 An. gambiae and 108 An. arabiensis. The Zimbabwe specimens consisted of 6 An. gambiae and 55 An. Quadriannulatus. All samples of the 3 species were polymorphic for the major chromosomal inversions previously recorded in field specimens from eastern and southern Africa, indicating that the collections reflected natural levels of intraspecific variation in the field populations sampled. Approximately 97% of the cytologically identified mosquitoes were also identified to species by the DNA probe method, and in every case the DNA probe and cytogenetic methods of species identification produced concordant results. PMID:3207175

  5. Daily rhythms in antennal protein and olfactory sensitivity in the malaria mosquito Anopheles gambiae

    PubMed Central

    Rund, Samuel S. C.; Bonar, Nicolle A.; Champion, Matthew M.; Ghazi, John P.; Houk, Cameron M.; Leming, Matthew T.; Syed, Zainulabeuddin; Duffield, Giles E.

    2013-01-01

    We recently characterized 24-hr daily rhythmic patterns of gene expression in Anopheles gambiae mosquitoes. These include numerous odorant binding proteins (OBPs), soluble odorant carrying proteins enriched in olfactory organs. Here we demonstrate that multiple rhythmically expressed genes including OBPs and takeout proteins, involved in regulating blood feeding behavior, have corresponding rhythmic protein levels as measured by quantitative proteomics. This includes AgamOBP1, previously shown as important to An. gambiae odorant sensing. Further, electrophysiological investigations demonstrate time-of-day specific differences in olfactory sensitivity of antennae to major host-derived odorants. The pre-dusk/dusk peaks in OBPs and takeout gene expression correspond with peak protein abundance at night, and in turn coincide with the time of increased olfactory sensitivity to odorants requiring OBPs and times of increased blood-feeding behavior. This suggests an important role for OBPs in modulating temporal changes in odorant sensitivity, enabling the olfactory system to coordinate with the circadian niche of An. gambiae. PMID:23986098

  6. The JNK Pathway Is a Key Mediator of Anopheles gambiae Antiplasmodial Immunity

    PubMed Central

    Garver, Lindsey S.; de Almeida Oliveira, Giselle; Barillas-Mury, Carolina

    2013-01-01

    The innate immune system of Anopheles gambiae mosquitoes limits Plasmodium infection through multiple molecular mechanisms. For example, midgut invasion by the parasite triggers an epithelial nitration response that promotes activation of the complement-like system. We found that suppression of the JNK pathway, by silencing either Hep, JNK, Jun or Fos expression, greatly enhanced Plasmodium infection; while overactivating this cascade, by silencing the suppressor Puckered, had the opposite effect. The JNK pathway limits infection via two coordinated responses. It induces the expression of two enzymes (HPx2 and NOX5) that potentiate midgut epithelial nitration in response to Plasmodium infection and regulates expression of two key hemocyte-derived immune effectors (TEP1 and FBN9). Furthermore, the An. gambiae L3–5 strain that has been genetically selected to be refractory (R) to Plasmodium infection exhibits constitutive overexpression of genes from the JNK pathway, as well as midgut and hemocyte effector genes. Silencing experiments confirmed that this cascade mediates, to a large extent, the drastic parasite elimination phenotype characteristic of this mosquito strain. In sum, these studies revealed the JNK pathway as a key regulator of the ability of An. gambiae mosquitoes to limit Plasmodium infection and identified several effector genes mediating these responses. PMID:24039583

  7. The JNK pathway is a key mediator of Anopheles gambiae antiplasmodial immunity.

    PubMed

    Garver, Lindsey S; de Almeida Oliveira, Giselle; Barillas-Mury, Carolina

    2013-01-01

    The innate immune system of Anopheles gambiae mosquitoes limits Plasmodium infection through multiple molecular mechanisms. For example, midgut invasion by the parasite triggers an epithelial nitration response that promotes activation of the complement-like system. We found that suppression of the JNK pathway, by silencing either Hep, JNK, Jun or Fos expression, greatly enhanced Plasmodium infection; while overactivating this cascade, by silencing the suppressor Puckered, had the opposite effect. The JNK pathway limits infection via two coordinated responses. It induces the expression of two enzymes (HPx2 and NOX5) that potentiate midgut epithelial nitration in response to Plasmodium infection and regulates expression of two key hemocyte-derived immune effectors (TEP1 and FBN9). Furthermore, the An. gambiae L3-5 strain that has been genetically selected to be refractory (R) to Plasmodium infection exhibits constitutive overexpression of genes from the JNK pathway, as well as midgut and hemocyte effector genes. Silencing experiments confirmed that this cascade mediates, to a large extent, the drastic parasite elimination phenotype characteristic of this mosquito strain. In sum, these studies revealed the JNK pathway as a key regulator of the ability of An. gambiae mosquitoes to limit Plasmodium infection and identified several effector genes mediating these responses. PMID:24039583

  8. Polymorphism at the defensin gene in the Anopheles gambiae complex: testing different selection hypotheses

    PubMed Central

    Simard, Frédéric; Licht, Monica; Besansky, Nora J.; Lehmann, Tovi

    2007-01-01

    Genetic variation in defensin, a gene encoding a major effector molecule of insects immune response was analyzed within and between populations of three members of the Anopheles gambiae complex. The species selected included the two anthropophilic species, An. gambiae and An. arabiensis and the most zoophilic species of the complex, An. quadriannulatus. The first species was represented by four populations spanning its extreme genetic and geographical ranges, whereas each of the other two species was represented by a single population. We found (i) reduced overall polymorphism in the mature peptide region and in the total coding region, together with specific reductions in rare and moderately frequent mutations (sites) in the coding region compared with non coding regions, (ii) markedly reduced rate of nonsynonymous diversity compared with synonymous variation in the mature peptide and virtually identical mature peptide across the three species, and (iii) increased divergence between species in the mature peptide together with reduced differentiation between populations of An. gambiae in the same DNA region. These patterns suggest a strong purifying selection on the mature peptide and probably the whole coding region. Because An. quadriannulatus is not exposed to human pathogens, identical mature peptide and similar pattern of polymorphism across species implies that human pathogens played no role as selective agents on this peptide. PMID:17161659

  9. Immune factor Gambif1, a new rel family member from the human malaria vector, Anopheles gambiae.

    PubMed

    Barillas-Mury, C; Charlesworth, A; Gross, I; Richman, A; Hoffmann, J A; Kafatos, F C

    1996-09-01

    A novel rel family member, Gambif1 (gambiae immune factor 1), has been cloned from the human malaria vector, Anopheles gambiae, and shown to be most similar to Drosophila Dorsal and Dif. Gambif1 protein is translocated to the nucleus in fat body cells in response to bacterial challenge, although the mRNA is present at low levels at all developmental stages and is not induced by infection. DNA binding activity to the kappaB-like sites in the A.gambiae Defensin and the Drosophila Diptericin and Cecropin promoters is also induced in larval nuclear extracts following infection. Gambif1 has the ability to bind to kappaB-like sites in vitro. Co-transfection assays in Drosophila mbn-2 cells show that Gambif1 can activate transcription by interacting with the Drosophila Diptericin regulatory elements, but is not functionally equivalent to Dorsal in this assay. Gambif1 protein translocation to the nucleus and the appearance of kappaB-like DNA binding activity can serve as molecular markers of activation of the immune system and open up the possibility of studying the role of defence reactions in determining mosquito susceptibility/refractoriness to malaria infection. PMID:8887560

  10. Role of Fish as Predators of Mosquito Larvae on the Floodplain of the Gambia River

    PubMed Central

    LOUCA, VASILIS; LUCAS, MARTYN C.; GREEN, CLARE; MAJAMBERE, SILAS; FILLINGER, ULRIKE; LINDSAY, STEVE W.

    2009-01-01

    We examined the potential of using native fish species in regulating mosquitoes in the floodplain of the Gambia River, the major source of mosquitoes in rural parts of The Gambia. Fishes and mosquito larvae were sampled along two 2.3-km-long transects, from the landward edge of the floodplain to the river from May to November 2005 to 2007. A semifield trial was used to test the predatory capacity of fish on mosquito larvae and the influence of fish chemical cues on oviposition. In the field, there was less chance of finding culicine larvae where Tilapia guineensis, the most common floodplain fish, were present; however, the presence of anophelines was not related to the presence or absence of any fish species. In semifield trials, both T. guineensis and Epiplatys spilargyreius were effective predators, removing all late-stage culicine and anopheline larvae within 1 d. Fewer culicines oviposited in sites with fish, suggesting that ovipositing culicine females avoid water with fish. In contrast, oviposition by anophelines was unaffected by fish. Our studies show that T. guineensis is a potential candidate for controlling mosquitoes in The Gambia. PMID:19496426

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

    PubMed Central

    Okumu, Fredros O; Knols, Bart GJ; Fillinger, Ulrike

    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. Methods To assess the larvicidal efficacy of a neem (Azadirachta indica) oil formulation (azadirachtin content of 0.03% w/v) on An. gambiae s.s., larvae were exposed as third and fourth instars to a normal diet supplemented with the neem oil formulations in different concentrations. A control group of larvae was exposed to a corn oil formulation in similar concentrations. Results Neem oil had an LC50 value of 11 ppm after 8 days, which was nearly five times more toxic than the corn oil formulation. Adult emergence was inhibited by 50% at a concentration of 6 ppm. Significant reductions on growth indices and pupation, besides prolonged larval periods, were observed at neem oil concentrations above 8 ppm. The corn oil formulation, in contrast, produced no growth disruption within the tested range of concentrations. Conclusion Neem oil has good larvicidal properties for An. gambiae s.s. and suppresses successful adult emergence at very low concentrations. Considering the wide distribution and availability of this tree and its products along the East African coast, this may prove a readily available and cheap alternative to conventional larvicides. PMID:17519000

  12. Dihydroisoxazole inhibitors of Anopheles gambiae seminal transglutaminase AgTG3

    PubMed Central

    2014-01-01

    Background Current vector-based malaria control strategies are threatened by the rise of biochemical and behavioural resistance in mosquitoes. Researching mosquito traits of immunity and fertility is required to find potential targets for new vector control strategies. The seminal transglutaminase AgTG3 coagulates male Anopheles gambiae seminal fluids, forming a ‘mating plug’ that is required for male reproductive success. Inhibitors of AgTG3 can be useful both as chemical probes of A. gambiae reproductive biology and may further the development of new chemosterilants for mosquito population control. Methods A targeted library of 3-bromo-4,5-dihydroxoisoxazole inhibitors were synthesized and screened for inhibition of AgTG3 in a fluorescent, plate-based assay. Positive hits were tested for in vitro activity using cross-linking and mass spectrometry, and in vivo efficacy in laboratory mating assays. Results A targeted chemical library was screened for inhibition of AgTG3 in a fluorescent plate-based assay using its native substrate, plugin. Several inhibitors were identified with IC50 < 10 μM. Preliminary structure-activity relationships within the library support the stereo-specificity and preference for aromatic substituents in the chemical scaffold. Both inhibition of plugin cross-linking and covalent modification of the active site cysteine of AgTG3 were verified. Administration of an AgTG3 inhibitor to A. gambiae males by intrathoracic injection led to a 15% reduction in mating plug transfer in laboratory mating assays. Conclusions A targeted screen has identified chemical inhibitors of A. gambiae transglutaminase 3 (AgTG3). The most potent inhibitors are known inhibitors of human transglutaminase 2, suggesting a common binding pose may exist within the active site of both enzymes. Future efforts to develop additional inhibitors will provide chemical tools to address important biological questions regarding the role of the A. gambiae mating plug. A

  13. Multiple insecticide resistance mechanisms in Anopheles gambiae s.l. populations from Cameroon, Central Africa

    PubMed Central

    2013-01-01

    Background Increasing incidence of DDT and pyrethroid resistance in Anopheles mosquitoes is seen as a limiting factor for malaria vector control. The current study aimed at an in-depth characterization of An. gambiae s.l. resistance to insecticides in Cameroon, in order to guide malaria vector control interventions. Methods Anopheles gambiae s.l. mosquitoes were collected as larvae and pupae from six localities spread throughout the four main biogeographical domains of Cameroon and reared to adults in insectaries. Standard WHO insecticide susceptibility tests were carried out with 4% DDT, 0.75% permethrin and 0.05% deltamethrin. Mortality rates and knockdown times (kdt50 and kdt95) were determined and the effect of pre-exposure to the synergists DEF, DEM and PBO was assessed. Tested mosquitoes were identified to species and molecular forms (M or S) using PCR-RFLP. The hot ligation method was used to depict kdr mutations and biochemical assays were conducted to assess detoxifying enzyme activities. Results The An. arabiensis population from Pitoa was fully susceptible to DDT and permethrin (mortality rates > 98%) and showed reduced susceptibility to deltamethrin. Resistance to DDT was widespread in An. gambiae s.s. populations and heterogeneous levels of susceptibility to permethrin and deltamethrin were observed. In many cases, prior exposure to synergists partially restored insecticide knockdown effect and increased mortality rates, suggesting a role of detoxifying enzymes in increasing mosquito survival upon challenge by pyrethroids and, to a lower extent DDT. The distribution of kdr alleles suggested a major role of kdr-based resistance in the S form of An. gambiae. In biochemical tests, all but one mosquito population overexpressed P450 activity, whereas baseline GST activity was low and similar in all field mosquito populations and in the control. Conclusion In Cameroon, multiple resistance mechanisms segregate in the S form of An. gambiae resulting in

  14. Insecticide resistance monitoring of field-collected Anopheles gambiae s.l. populations from Jinja, eastern Uganda, identifies high levels of pyrethroid resistance

    PubMed Central

    Mawejje, Henry D.; Wilding, Craig S.; Rippon, Emily J.; Hughes, Angela; Weetman, David; Donnelly, Martin J.

    2012-01-01

    Insecticide resistance in the malaria vector An. gambiae s.l. threatens insecticide-based control efforts, necessitating regular monitoring. We assessed resistance in field-collected An. gambiae s.l. from Jinja, Uganda using WHO biosassays. Only An. gambiae s.s. and An. arabiensis (≈70%) were present. Female An. gambiae exhibited extremely high pyrethroid resistance (permethrin LT50 >2h; deltamethrin LT50 >5h). Female An. arabiensis were resistant to permethrin and exhibited reduced susceptibility to deltamethrin. However, whilst An. gambiae were DDT resistant, An. arabiensis were fully susceptible. Both species were fully susceptible to bendiocarb and fenitrothion. Kdr 1014S has increased rapidly in the Jinja population of An. gambiae s.s. and now approaches fixation (≈95%), consistent with insecticide-mediated selection, but is currently at low frequency in An. arabiensis (0.07%). Kdr 1014F was also at low frequency in An. gambiae. These frequencies preclude adequately-powered tests for association with phenotypic resistance. PBO synergist bioassays resulted in near complete recovery of pyrethroid susceptibility suggesting involvement of CYP450s in resistance. A small number (0.22%) of An. gambiae s.s. x An. arabiensis hybrids were found, suggesting the possibility of introgression of resistance alleles between species. The high levels of pyrethroid resistance encountered in Jinja threaten to reduce the efficacy of vector control programmes which rely on pyrethroid impregnated bednets or indoor spraying of pyrethroids. PMID:23046446

  15. Sex-specific and blood meal-induced proteins of Anopheles gambiae midguts: analysis by two-dimensional gel electrophoresis

    PubMed Central

    Prévot, GI; Laurent-Winter, C; Rodhain, F; Bourgouin, C

    2003-01-01

    Background Anopheles gambiae is the main vector of Plasmodium falciparum in Africa. The mosquito midgut constitutes a barrier that the parasite must cross if it is to develop and be transmitted. Despite the central role of the mosquito midgut in the host/parasite interaction, little is known about its protein composition. Characterisation of An. gambiae midgut proteins may identify the proteins that render An. gambiae receptive to the malaria parasite. Methods We carried out two-dimensional gel electrophoresis of An. gambiae midgut proteins and compared protein profiles for midguts from males, sugar-fed females and females fed on human blood. Results Very few differences were detected between male and female mosquitoes for the approximately 375 silver-stained proteins. Male midguts contained ten proteins not detected in sugar-fed or blood-fed females, which are therefore probably involved in male-specific functions; conversely, female midguts contained twenty-three proteins absent from male midguts. Eight of these proteins were specific to sugar-fed females, and another ten, to blood-fed females. Conclusion Mass spectrometry analysis of the proteins found only in blood-fed female midguts, together with data from the recent sequencing of the An. gambiae genome, should make it possible to determine the role of these proteins in blood digestion or parasite receptivity. PMID:12605724

  16. The Anopheles gambiae Odorant Binding Protein 1 (AgamOBP1) Mediates Indole Recognition in the Antennae of Female Mosquitoes

    PubMed Central

    Andronopoulou, Evi; Biessmann, Max R.; Douris, Vassilis; Dimitratos, Spiros D.; Eliopoulos, Elias; Guerin, Patrick M.; Iatrou, Kostas; Justice, Robin W.; Kröber, Thomas; Marinotti, Osvaldo; Tsitoura, Panagiota; Woods, Daniel F.; Walter, Marika F.

    2010-01-01

    Haematophagous insects are frequently carriers of parasitic diseases, including malaria. The mosquito Anopheles gambiae is the major vector of malaria in sub-Saharan Africa and is thus responsible for thousands of deaths daily. Although the role of olfaction in A. gambiae host detection has been demonstrated, little is known about the combinations of ligands and odorant binding proteins (OBPs) that can produce specific odor-related responses in vivo. We identified a ligand, indole, for an A. gambiae odorant binding protein, AgamOBP1, modeled the interaction in silico and confirmed the interaction using biochemical assays. RNAi-mediated gene silencing coupled with electrophysiological analyses confirmed that AgamOBP1 binds indole in A. gambiae and that the antennal receptor cells do not respond to indole in the absence of AgamOBP1. This case represents the first documented instance of a specific A. gambiae OBP–ligand pairing combination, demonstrates the significance of OBPs in odor recognition, and can be expanded to the identification of other ligands for OBPs of Anopheles and other medically important insects. PMID:20208991

  17. Spatio-Temporal Patterns in kdr Frequency in Permethrin and DDT Resistant Anopheles gambiae s.s. from Uganda

    PubMed Central

    Verhaeghen, Katrijn; Bortel, Wim Van; Roelants, Patricia; Okello, Paul Edward; Talisuna, Ambrose; Coosemans, Marc

    2010-01-01

    The planned upscaling of vector control strategies requires insight into the epidemiological consequences of vector resistance. Therefore, the pyrethroid and DDT resistance status of Anopheles gambiae s.l. was assessed in Uganda from 2004 to 2006, and spatial and seasonal variations in knockdown resistance (kdr) frequencies were analyzed in terms of epidemiological significance. Anopheles gambiae s.l. was DDT and pyrethroid resistant in central and eastern Uganda. The L1014S kdr allele frequencies varied from 3% to 48% in An. gambiae s.s. Although the homozygous resistant genotype was the most prevalent genotype among survivors, the genotypes could not entirely explain the bioassay results. In the dry season, the kdr frequency was significantly higher in Plasmodium falciparum-infected mosquitoes, indicating that mosquitoes bearing a kdr mutation have a better adult survival, hence a higher likelihood of becoming infectious. This study showed that kdr might have an epidemiological impact that could jeopardize the vector control strategies. PMID:20348500

  18. Effects of plant-community composition on the vectorial capacity and fitness of the malaria mosquito Anopheles gambiae.

    PubMed

    Stone, Christopher M; Jackson, Bryan T; Foster, Woodbridge A

    2012-10-01

    Dynamics of Anopheles gambiae abundance and malaria transmission potential rely strongly on environmental conditions. Female and male An. gambiae use sugar and are affected by its absence, but how the presence or absence of nectariferous plants affects An. gambiae abundance and vectorial capacity has not been studied. We report on four replicates of a cohort study performed in mesocosms with sugar-poor and sugar-rich plants, in which we measured mosquito survival, biting rates, and fecundity. Survivorship was greater with access to sugar-rich plant species, and mortality patterns were age-dependent. Sugar-poor populations experienced Weibull mortality patterns, and of four populations in the sugar-rich environment, two female and three male subpopulations were better fitted by Gompertz functions. A tendency toward higher biting rates in sugar-poor mesocosms, particularly for young females, was found. Therefore, vectorial capacity was pulled in opposing directions by nectar availability, resulting in highly variable vectorial capacity values. PMID:22927493

  19. Effects of Plant-Community Composition on the Vectorial Capacity and Fitness of the Malaria Mosquito Anopheles gambiae

    PubMed Central

    Stone, Christopher M.; Jackson, Bryan T.; Foster, Woodbridge A.

    2012-01-01

    Dynamics of Anopheles gambiae abundance and malaria transmission potential rely strongly on environmental conditions. Female and male An. gambiae use sugar and are affected by its absence, but how the presence or absence of nectariferous plants affects An. gambiae abundance and vectorial capacity has not been studied. We report on four replicates of a cohort study performed in mesocosms with sugar-poor and sugar-rich plants, in which we measured mosquito survival, biting rates, and fecundity. Survivorship was greater with access to sugar-rich plant species, and mortality patterns were age-dependent. Sugar-poor populations experienced Weibull mortality patterns, and of four populations in the sugar-rich environment, two female and three male subpopulations were better fitted by Gompertz functions. A tendency toward higher biting rates in sugar-poor mesocosms, particularly for young females, was found. Therefore, vectorial capacity was pulled in opposing directions by nectar availability, resulting in highly variable vectorial capacity values. PMID:22927493

  20. Differences in timing of mating swarms in sympatric populations of Anopheles coluzzii and Anopheles gambiae s.s. (formerly An. gambiae M and S molecular forms) in Burkina Faso, West Africa

    PubMed Central

    2013-01-01

    Background The M and S molecular forms of Anopheles gambiae s.s. Giles appear to have speciated in West Africa and the M form is now formally named An. coluzzii Coetzee & Wilkerson sp.n. and the S form retains the nominotypical name (abbreviated here to An. gambiae). Reproductive isolation is thought to be the main barrier to hybridisation; even though both species are found in the same mating swarms, hybrid fertilisations in copulae have not been found in the study area. The aim of the study, therefore, was to determine whether differences in circadian and/or environmental control over the timing of swarming in the two species contribute to reproductive isolation. Methods The timing of male swarming in these species was recorded four nights per month over four years at five swarming sites in each of two villages. The timing of the start and end of swarming, and the concurrent environmental parameters, temperature, humidity and light intensity, were recorded for n = 20 swarms/month/species. The timing of 'spontaneous’ activity at dusk of individual An. coluzzii and An. gambiae males was video-recorded in an actograph outdoors for 21 nights. Results Of the environmental parameters considered, swarming was most strongly correlated with sunset (r2 > 0.946). Anopheles gambiae started and stopped swarming earlier than An. coluzzii (3:35 ± 0:68 min:sec and 4:51 ± 1:21, respectively), and the mean duration of swarming was 23:37 ± 0:33 for An. gambiae and 21:39 ± 0:33 for An. coluzzii. Accordingly, in principle, whenever both species swarm over the same marker, a mean of 15.3 ± 3.1% of An. gambiae swarming would occur before An. coluzzii males arrived, and 19.5 ± 4.55% of An. coluzzii swarming would occurred after An. gambiae males had stopped swarming. These results are consistent with the finding that An. gambiae males became active in the actograph 09:35 ± 00:22 min:sec earlier than An. coluzzii males. Conclusions The

  1. Toxicity of essential oil from Indian borage on the larvae of the African malaria vector mosquito, Anopheles gambiae

    PubMed Central

    2012-01-01

    Background Essential oils are currently studied for the control of different disease vectors, because of their efficacy on targeted organisms. In the present investigation, the larvicidal potential of essential oil extracted from Indian borage (Plectranthus amboinicus) was studied against the African anthropophagic malaria vector mosquito, Anopheles gambiae. The larvae of An. gambiae s.s laboratory colony and An. gambiae s.l of wild populations were assayed and the larval mortality was observed at 12, 24 and 48 h after exposure period with the concentrations of 3.125, 6.25, 12.5, 25, 50 and 100 ppm. Findings Larval mortality rates of the essential oil was entirely time and dose dependent. The LC50 values of the laboratory colony were 98.56 (after 12h) 55.20 (after 24 h) and 32.41 ppm (after 48 h) and the LC90 values were 147.40 (after 12h), 99.09 (after 24 h) and 98.84 ppm (after 48 h). The LC50 and LC90 values of the wild population were 119.52, 179.85 (after 12h) 67.53, 107.60 (after 24 h) and 25.51, 111.17 ppm (after 48 h) respectively. The oil showed good larvicidal potential after 48 h of exposure period against An. gambiae. The essential oil of Indian borage is a renowned natural source of larvicides for the control of the African malaria vector mosquito, An. gambiae. Conclusion The larvicidal efficacy shown by plant extracts against An. gambiae should be tested in semi field and small scale trials for effective compounds to supplement the existing larval control tools. PMID:23206364

  2. Select Small Core Structure Carbamates Exhibit High Contact Toxicity to “Carbamate-Resistant” Strain Malaria Mosquitoes, Anopheles gambiae (Akron)

    PubMed Central

    Wong, Dawn M.; Li, Jianyong; Chen, Qiao-Hong; Han, Qian; Mutunga, James M.; Wysinski, Ania; Anderson, Troy D.; Ding, Haizhen; Carpenetti, Tiffany L.; Verma, Astha; Islam, Rafique; Paulson, Sally L.; Lam, Polo C.-H.; Totrov, Maxim; Bloomquist, Jeffrey R.; Carlier, Paul R.

    2012-01-01

    Acetylcholinesterase (AChE) is a proven target for control of the malaria mosquito (Anopheles gambiae). Unfortunately, a single amino acid mutation (G119S) in An. gambiae AChE-1 (AgAChE) confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying. In this report, we describe several carbamate inhibitors that potently inhibit G119S AgAChE and that are contact-toxic to carbamate-resistant An. gambiae. PCR-RFLP analysis was used to confirm that carbamate-susceptible G3 and carbamate-resistant Akron strains of An. gambiae carry wild-type (WT) and G119S AChE, respectively. G119S AgAChE was expressed and purified for the first time, and was shown to have only 3% of the turnover number (kcat) of the WT enzyme. Twelve carbamates were then assayed for inhibition of these enzymes. High resistance ratios (>2,500-fold) were observed for carbamates bearing a benzene ring core, consistent with the carbamate-resistant phenotype of the G119S enzyme. Interestingly, resistance ratios for two oxime methylcarbamates, and for five pyrazol-4-yl methylcarbamates were found to be much lower (4- to 65-fold). The toxicities of these carbamates to live G3 and Akron strain An. gambiae were determined. As expected from the enzyme resistance ratios, carbamates bearing a benzene ring core showed low toxicity to Akron strain An. gambiae (LC50>5,000 μg/mL). However, one oxime methylcarbamate (aldicarb) and five pyrazol-4-yl methylcarbamates (4a–e) showed good to excellent toxicity to the Akron strain (LC50 = 32–650 μg/mL). These results suggest that appropriately functionalized “small-core” carbamates could function as a resistance-breaking anticholinesterase insecticides against the malaria mosquito. PMID:23049714

  3. Serologic survey of the wild boar (Sus scrofa) for Borrelia burgdorferi sensu lato.

    PubMed

    Juricová, Z; Hubálek, Z

    2009-10-01

    Sera of 642 wild boars (Sus scrofa) shot by hunters in ten administrative regions of the Czech Republic during 1995-2000, were tested by indirect hemagglutination assay (IHA) for the presence of anti-Borrelia IgG. Antibodies to Borrelia burgdorferi sensu lato (Bb) were detected in serum samples from all 10 regions, and overall seroprevalence rate was 12.8%. Titres of antibodies ranged from 1:80 to 1:640. Borrelia antibodies were most frequent in the animals from three administrative regions of the Czech Republic: Moravskoslezsky (25.0%), Pardubicky (25.0%) and Královehradecky (24.1%), followed by the regions Plzen sky (16.7%), Olomoucky (13.3%), Jihomoravsky (12.8%), Vysoc ina (11.1%), Jihoc esky (11.1%), Zlínsky (10.3%), and Liberecky (8.9%). Seasonal seroprevalence rate increased in March and April, the peak was in May. The results suggest frequent exposure of wild boars to ixodid ticks infected with Bb, predominantly in rural and forested regions. The study also reviews the importance of wild boar in Lyme borreliosis (LB) ecology. Wild boar serology may provide another means of surveillance of endemic areas of LB. PMID:18973452

  4. Structures of xyloglucans in primary cell walls of gymnosperms, monilophytes (ferns sensu lato) and lycophytes.

    PubMed

    Hsieh, Yves S Y; Harris, Philip J

    2012-07-01

    Little is known about the structures of the xyloglucans in the primary cell walls of vascular plants (tracheophytes) other than angiosperms. Xyloglucan structures were examined in 13 species of gymnosperms, 13 species of monilophytes (ferns sensu lato), and two species of lycophytes. Wall preparations were obtained, extracted with 6 M sodium hydroxide, and the extracts treated with a xyloglucan-specific endo-(1→4)-β-glucanase preparation. The oligosaccharides released were analysed by matrix-assisted laser-desorption ionisation time-of-flight mass spectrometry and by high-performance anion-exchange chromatography. The xyloglucan oligosaccharide profiles from the gymnosperm walls were similar to those from the walls of most eudicotyledons and non-commelinid monocotyledons, indicating that the xyloglucans were fucogalactoxyloglucans, containing the fucosylated units XXFG and XLFG. The xyloglucan oligosaccharide profiles for six of the monilophyte species were similar to those of the gymnosperms, indicating they were also fucogalactoxyloglucans. Phylogenetically, these monilophyte species were from both basal and more derived orders. However, the profiles for the other monilophyte species showed various significant differences, including additional oligosaccharides. In three of the species, these additional oligosaccharides contained arabinosyl residues which were most abundant in the profile of Equisetum hyemale. The two species of lycophytes examined, Selaginella kraussiana and Lycopodium cernuum, had quite different xyloglucan oligosaccharide profiles, but neither were fucogalactoxyloglucans. The S. kraussiana profile had abundant oligosaccharides containing arabinosyl residues. The L. cernuum profile indicated the xyloglucan had a very complex structure. PMID:22537406

  5. Identification of Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato in patients with erythema migrans.

    PubMed

    Hulínská, D; Votýpka, J; Vanousová, D; Hercogová, J; Hulínský, V; Drevová, H; Kurzová, Z; Uherková, L

    2009-01-01

    Anaplasma phagocytophilum has been first isolated from the blood of two Czech patients simultaneously with a cultivation of Borrelia burgdorferi sensu lato from their erythema migrans lesions. Cultivation of different Borrelia spp. from 12 erythema migrans biopsies, from 2 blood, one liquor and one placenta sample in BSK-H medium was successful. Adapted conventional methods targeting 16S rRNA and OspA genes for real-time polymerase chain reaction (PCR) and partial sequencing of these genes together with microscopical examinations of the blood smears provided a direct detection of the B. afzelii, B. burgdorferi, B. garinii, B. valaisiana and B. bissettii in the skin, B. garinii in the blood, placenta and liquor in 24 (36.3 %) patients, and A. phagocytophilum in 10 (15 %) patients with erythema migrans. Positive indirect IgM immunofluorescence against Anaplasma sp. was obtained in 7 cases, specific IgG antibodies were detected in 12 patients. Three women suffering from erythema migrans in the first trimester had positive PCR for Anaplasma and/or for Borrelia in the blood and two of them, later, in the placenta. Interpretation of laboratory data can bring important contribution to establishing the role of Anaplasma sp. in erythema migrans and forming the principle of precaution with laboratory diagnosis during pregnancy which always should be reflected in the resistance of Anaplasma sp. toward penicillins. PMID:19649743

  6. Seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in Italian horses.

    PubMed

    Ebani, Valentina V; Bertelloni, Fabrizio; Pinzauti, Paolo; Cerri, Domenico

    2012-01-01

    The aim of the study was to determine the seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in healthy horses living in 7 provinces of central Italy. In the period 2007-2009, sera from 386 horses were tested by microagglutination test (MAT) to detect antibodies to Leptospira spp., employing the following serovars as antigens: Bratislava, Ballum, Canicola, Icterohaemorrhagiae, Grippotyphosa, Hardjo, Pomona, Tarassovi. 3 animals were positive for the serovars Icterohaemorrhagiae, 2 to Bratislava, and 1 to Pomona, for a total 1.5% seroprevalence. All sera were examined by immunofluorence antibody test (IFAT) to reveal anti-B. burgdorferi s.l. antibodies. 94 (24.3%) horses were positive with antibody titres ranging from 1:64 to 1:1,024. The seroprevalence was significantly higher in >10 year-old horses compared to younger subjects. No significant differences in the mean seroprevalence were observed in the respective years. The total mean seroprevalence were strictly related to the environmental conditions of the areas in which the horses lived. No cross-reactions between Leptospira and Borrelia were observed. This is the first serological survey on antibodies to B. burgdorferi s.l. in Italian horses. PMID:22742794

  7. Comparative exine ontogeny in some members of the family Zygophyllaceae sensu lato.

    PubMed

    Nasri-Ayachi, M Ben; Nabli, M A

    2006-08-01

    Exine ontogeny is studied in five taxa of the family Zygophyllaceae sensu lato (Peganum harmala L., Zygophyllum album L., Fagonia cretica L., Tribulus terrestris L., and Nitraria retusa [Forsk.] Asch.). In the beginning of the tetrad stage, the plasmalemma is attached to the callose wall, except in T. terrestris, where it describes crests and hollows. The primexine matrix is fibrillar, bilayered in T. terrestris and unilayered in the other taxa. In all species except P. harmala, the procolumellae are heterogeneous with clear zones and they become compact later. In T. terrestris, they are built on the crests. In Z. album and T. terrestris, a primordial nexinic lamella is set up. It is tripartite with a white line seen at some levels; on its external leaflet, the foot layer is observed, and on its internal leaflet, there is the endexine with numerous lamellae. This white line disappears often in the mature exine. In T. terrestris, there is a thick nexine that is coarsely lamellate inside. In the aperture zone, the columellae are lacking, the tectum and the foot layer get thinner; they unite and form the apertural membrane with the external part of the endexine. There is a granulolamellar endexinic zone well developed in P. harmala, whereas it is threelayered and weakly developed in T. terrestris. PMID:16937054

  8. Polysynovitis in a horse due to Borrelia burgdorferi sensu lato infection--Case study.

    PubMed

    Passamonti, Fabrizio; Veronesi, Fabrizia; Cappelli, Katia; Capomaccio, Stefano; Reginato, Alice; Miglio, Arianna; Vardi, Doron M; Stefanetti, Valentina; Coletti, Mauro; Bazzica, Chiara; Pepe, Marco

    2015-01-01

    Lyme borreliosis (LB) is a multi-systemic tick-borne disease affecting both humans and animals, including horses, and is caused by a group of interrelated spirochetes classified within the Borrelia burgdorferi sensu lato (s.l.) complex. Despite the high reported seroprevalence in the European equine population for B. burgdorferi s.l., to-date no documented clinical cases have been described. A 6-year-old Paint gelding was referred with a history of three weeks of fever, intermittent lameness and digital flexor tendon sheath effusion of the right hind limb. Based on a strict diagnostic protocol, which included serological tests for infectious diseases and molecular investigations, a final diagnosis was made of polysynovitis due to B. burgdorferi s.l. infection. An unreported aspect observed in this case was the absence of the pathogen DNA in two of the affected joints. To the authors' knowledge, the case described represents the first documented clinical case of equine LB in Italy. Moreover, the absence of pathogen DNA in two of the affected joints observed in this case revealed a possible similarity with the same condition described in humans, where an immunomediated pathogenesis for arthropathy due to B. burgdorferi s.l. infection is suspected. Since humans and horses share the same habitat, this report supports the role of the horse as potential sentinel for human biological risk. PMID:26094517

  9. A taxonomic review of the Neoserica (sensu lato) abnormis group (Coleoptera, Scarabaeidae, Sericini).

    PubMed

    Ahrens, Dirk; Liu, Wan-Gang; Fabrizi, Silvia; Bai, Ming; Yang, Xing-Ke

    2014-01-01

    The present paper revises the species belonging to the Neoserica (sensu lato) abnormis group, so far known only with two nominal species. Twenty new species are herein described from Indochina and southern China: N. abnormoides sp. n. (Vietnam, China), N. allolaotica sp. n., N. namthaensis sp. n., N. simplicissima sp. n. (Laos), N. thailandensis sp. n. (Thailand), N. alloputaoana sp. n., N. kanphantensis sp. n., N. natmatoungensis sp. n., N. putaoana sp. n., N. taunggyiana sp. n. (Myanmar), N. lamellosa sp. n., N. tonkinea sp. n. (Vietnam), N. bairailingshanica sp. n., N. euyunnanica sp. n., N. huangi sp. n., N. jiangxiensis sp. n., N. trifida sp. n., N. yaoi sp. n., N. yingjiangensis sp. n. (China), N. cardamomensis sp. n. (Indochina and southern China). One new combination is established: Neoserica ponderosa Arrow, 1946, comb. n. The lectotypes of Neoserica abnormis Moser, 1908 and the taxonomically uncertain N. inclinata Brenske, 1898, which very likely also belongs to this species group, are designated herein. A key to the species and to species groups is given, the genitalia of all species including their habitus are illustrated. Maps of species distribution are included. PMID:25317056

  10. A taxonomic review of the Neoserica (sensu lato) abnormis group (Coleoptera, Scarabaeidae, Sericini)

    PubMed Central

    Ahrens, Dirk; Liu, Wan-Gang; Fabrizi, Silvia; Bai, Ming; Yang, Xing-Ke

    2014-01-01

    Abstract The present paper revises the species belonging to the Neoserica (sensu lato) abnormis group, so far known only with two nominal species. Twenty new species are herein described from Indochina and southern China: N. abnormoides sp. n. (Vietnam, China), N. allolaotica sp. n., N. namthaensis sp. n., N. simplicissima sp. n. (Laos), N. thailandensis sp. n. (Thailand), N. alloputaoana sp. n., N. kanphantensis sp. n., N. natmatoungensis sp. n., N. putaoana sp. n., N. taunggyiana sp. n. (Myanmar), N. lamellosa sp. n., N. tonkinea sp. n. (Vietnam), N. bairailingshanica sp. n., N. euyunnanica sp. n., N. huangi sp. n., N. jiangxiensis sp. n., N. trifida sp. n., N. yaoi sp. n., N. yingjiangensis sp. n. (China), N. cardamomensis sp. n. (Indochina and southern China). One new combination is established: Neoserica ponderosa Arrow, 1946, comb. n. The lectotypes of Neoserica abnormis Moser, 1908 and the taxonomically uncertain N. inclinata Brenske, 1898, which very likely also belongs to this species group, are designated herein. A key to the species and to species groups is given, the genitalia of all species including their habitus are illustrated. Maps of species distribution are included. PMID:25317056

  11. Population genetic structure of Anopheles gambiae mosquitoes on Lake Victoria islands, west Kenya

    PubMed Central

    Chen, Hong; Minakawa, Noboru; Beier, John; Yan, Guiyun

    2004-01-01

    Background Understanding the genetic structure of island Anopheles gambiae populations is important for the current tactics in mosquito control and for the proposed strategy using genetically-modified mosquitoes (GMM). Genetically-isolated mosquito populations on islands are a potential site for testing GMM. The objective of this study was to determine the genetic structure of A. gambiae populations on the islands in Lake Victoria, western Kenya. Methods The genetic diversity and the population genetic structures of 13 A. gambiae populations from five islands on Lake Victoria and six villages from the surrounding mainland area in the Suba District were examined using six microsatellite markers. The distance range of sampling sites varied between 2.5 and 35.1 km. Results A similar level of genetic diversity between island mosquito populations and adjacent mainland populations was found. The average number of alleles per locus was 7.3 for the island populations and 6.8 for the mainland populations. The average observed heterozygosity was 0.32 and 0.28 for the island and mainland populations, respectively. A low but statistically significant genetic structure was detected among the island populations (FST = 0.019) and between the island and mainland populations (FST = 0.003). A total of 12 private alleles were found, and nine of them were from the island populations. Conclusion A level of genetic differentiation between the island and mainland populations was found. Large extent of gene flow between the island and mainland mosquito populations may result from wind- or human-assisted dispersal. Should the islands on Lake Victoria be used as a trial site for the release program of GMM, mosquito dispersal between the islands and between the island and the mainland should be vigorously monitored. PMID:15581429

  12. Functional development of carbon dioxide detection in the maxillary palp of Anopheles gambiae

    PubMed Central

    Omondi, Bonaventure Aman; Majeed, Shahid; Ignell, Rickard

    2015-01-01

    ABSTRACT Olfactory information drives several behaviours critical for the survival and persistence of insect pests and vectors. Insect behaviour is variable, linked to their biological needs, and regulated by physiological dynamics. For mosquitoes, CO2 is an important cue that signifies the presence of a host, and which elicits activation and attraction. To investigate the genetic basis of olfactory modulation in mosquitoes, we assayed changes in CO2 detection from receptor gene expression through physiological function to behaviour, associated with the onset of host seeking in the malaria vector, Anopheles gambiae. The gene encoding a subunit of the CO2 receptor, AgGr22, was found to be significantly up-regulated in host-seeking females, consistent with a significant increase in sensitivity of CO2-responsive neurons (cpA) housed in capitate peg sensilla of the maxillary palp. In addition, the odorant receptor AgOr28, which is expressed in cpC neurons, was significantly up-regulated. In contrast, AgOr8, which is expressed in cpB neurons, was not affected by this change in physiological state, in agreement with results for the obligate co-receptor Orco. Moreover, the sensitivity of the cpB neuron to (R)-1-octen-3-ol, a well-known mammalian kairomone, did not change in response to the onset of host seeking. The concentration of CO2 flux influenced both the propensity of A. gambiae to take off into the wind and the speed with which this activation occurred. Female A. gambiae mosquitoes responded to CO2 whether mature for host seeking or not, but onset of host seeking enhanced sensitivity and speed of activation at relevant doses of CO2. PMID:26056246

  13. Anopheles gambiae resistance to pyrethroid-treated nets in cotton versus rice areas in Mali.

    PubMed

    Fane, Moussa; Cissé, Ousmane; Traore, Cheick Sékou F; Sabatier, Philippe

    2012-04-01

    The rise and spread of Anopheles gambiae s.l. (the major malaria vector sub-Saharan Africa) resistance to pyrethroids is of great concern owing to the predominant role of pyrethroid-treated nets in the WHO global strategy for malaria control. Use of pyrethroids for agricultural purposes may exert a strong selection pressure, favouring the emergence of insecticide resistance. The objective of this study was to evaluate the efficacy of alpha-cypermethrin treated nets in settings where insecticides are used against pests. This was assessed in two ways, i.e. under laboratory conditions using the WHO standard cones test technique and in experimental huts, on Anopheles gambiae s.l. collected in two Malian rural sites, Koumantou characterised by cotton crops and high insecticide use and Sélingué, a rice field area with low insecticide use. According to the WHO standard cones test technique, there was no difference between mosquitoes collected in the two sites; KD50 time was less than 3 min and the KD95 time below 30 min. Nevertheless, in the experimental huts with alpha-cypermethrin treated bed nets, the mosquito mortality rate was significantly lower in Koumantou (102/361, 28.2%) than in Sélingué (122/233, 52.3%) (RR: 0.65, 95%CI: 0.56-0.76) (p<0.001). In addition, in Koumantou the percentage of unfed mosquitoes found in the veranda was much lower in the huts with untreated (26.0%, 33/127) than in those with treated nets (92.2%, 118/128) (p<0.01) while in Sélingué there was no difference between huts with treated and untreated bed nets. Alpha-cypermethrin treated bed nets had a significant effect on mortality and repelling behaviour of Anopheles gambiae s.l. though in Koumantou treated bed nets were less efficacious, possibly due to the intense use of pesticide for agriculture. PMID:22154879

  14. CLIPB8 is part of the prophenoloxidase activation system in Anopheles gambiae mosquitoes.

    PubMed

    Zhang, Xin; An, Chunju; Sprigg, KaraJo; Michel, Kristin

    2016-04-01

    In insects and other arthropods the formation of eumelanin (melanization) is a broad spectrum and potent immune response that is used to encapsulate and kill invading pathogens. This immune response is regulated by the activation of prophenoxidase (proPO), which is controlled by proteinase cascades and its serpin inhibitors, together forming the proPO activation system. While the molecular composition of these protease cascades are well understood in insect model systems, major knowledge gaps remain in mosquitoes. Recently, a regulatory unit of melanization in Anopheles gambiae was documented, comprised of the inhibitory serpin-clip-serine proteinase, CLIPB9 and its inhibitor serpin-2 (SRPN2). Partial reversion of SRPN2 phenotypes in melanotic tumor formation and adult survival by SRPN2/CLIPB9 double knockdown suggested other target proteinases of SRPN2 in regulating melanization. Here we report that CLIPB8 supplements the SRPN2/CLIPB9 regulatory unit in controlling melanization in An. gambiae. As with CLIPB9, knockdown of CLIPB8 partially reversed the pleiotropic phenotype induced by SRPN2 silencing with regards to adult survival and melanotic tumor formation. Recombinant SRPN2 protein formed an SDS-stable protein complex with activated recombinant CLIPB8, however did not efficiently inhibit CLIPB8 activity in vitro. CLIPB8 did not directly activate proPO in vitro nor was it able to cleave and activate proCLIPB9. Nevertheless, epistasis analysis using RNAi placed CLIPB8 and CLIPB9 in the same pathway leading to melanization, suggesting that CLIPB8 either acts further upstream of CLIPB9 or is required for activation of a yet to be identified serine proteinase homolog. Taken together, this study identifies CLIPB8 as an additional player in proPO activation cascade and highlights the complexity of the proteinase network that regulates melanization in An. gambiae. PMID:26926112

  15. Biochemical characterization of chitin synthase activity and inhibition in the African malaria mosquito, Anopheles gambiae.

    PubMed

    Zhang, Xin; Yan Zhu, Kun

    2013-04-01

    Chitin synthase (CHS) is an important enzyme catalyzing the formation of chitin polymers in all chitin containing organisms and a potential target site for insect pest control. However, our understanding of biochemical properties of insect CHSs has been very limited. We here report enzymatic and inhibitory properties of CHS prepared from the African malaria mosquito, Anopheles gambiae. Our study, which represents the first time to use a nonradioactive method to assay CHS activity in an insect species, determined the optimal conditions for measuring the enzyme activity, including pH, temperature, and concentrations of the substrate uridine diphosphate N-acetyl-d-glucosamine (UDP-GlcNAc) and Mg(++) . The optimal pH was about 6.5-7.0, and the highest activity was detected at temperatures between 37°C and 44°C. Dithithreitol is required to prevent melanization of the enzyme extract. CHS activity was enhanced at low concentration of GlcNAc, but inhibited at high concentrations. Proteolytic activation of the activity is significant both in the 500 ×g supernatant and the 40 000 ×g pellet. Our study revealed only slight in vitro inhibition of A. gambiae CHS activity by diflubenzuron and nikkomycin Z at the highest concentration (2.5 μmol/L) examined. There was no in vitro inhibition by polyoxin D at any concentration examined. Furthermore, we did not observe any in vivo inhibition of CHS activity by any of these chemicals at any concentration examined. Our results suggest that the inhibition of chitin synthesis by these chemicals is not due to direct inhibition of CHS in A. gambiae. PMID:23955856

  16. Reactive oxygen species modulate Anopheles gambiae immunity against bacteria and Plasmodium.

    PubMed

    Molina-Cruz, Alvaro; DeJong, Randall J; Charles, Bradley; Gupta, Lalita; Kumar, Sanjeev; Jaramillo-Gutierrez, Giovanna; Barillas-Mury, Carolina

    2008-02-01

    The involvement of reactive oxygen species (ROS) in mosquito immunity against bacteria and Plasmodium was investigated in the malaria vector Anopheles gambiae. Strains of An. gambiae with higher systemic levels of ROS survive a bacterial challenge better, whereas reduction of ROS by dietary administration of antioxidants significantly decreases survival, indicating that ROS are required to mount effective antibacterial responses. Expression of several ROS detoxification enzymes increases in the midgut and fat body after a blood meal. Furthermore, expression of several of these enzymes increases to even higher levels when mosquitoes are fed a Plasmodium berghei-infected meal, indicating that the oxidative stress after a blood meal is exacerbated by Plasmodium infection. Paradoxically, a complete lack of induction of catalase mRNA and lower catalase activity were observed in P. berghei-infected midguts. This suppression of midgut catalase expression is a specific response to ookinete midgut invasion and is expected to lead to higher local levels of hydrogen peroxide. Further reduction of catalase expression by double-stranded RNA-mediated gene silencing promoted parasite clearance by a lytic mechanism and reduced infection significantly. High mosquito mortality is often observed after P. berghei infection. Death appears to result in part from excess production of ROS, as mortality can be decreased by oral administration of uric acid, a strong antioxidant. We conclude that ROS modulate An. gambiae immunity and that the mosquito response to P. berghei involves a local reduction of detoxification of hydrogen peroxide in the midgut that contributes to limit Plasmodium infection through a lytic mechanism. PMID:18065421

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

    PubMed Central

    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. PMID:24675797

  18. Extensive circadian and light regulation of the transcriptome in the malaria mosquito Anopheles gambiae

    PubMed Central

    2013-01-01

    Background Mosquitoes exhibit 24 hr rhythms in flight activity, feeding, reproduction and development. To better understand the molecular basis for these rhythms in the nocturnal malaria vector Anopheles gambiae, we have utilized microarray analysis on time-of-day specific collections of mosquitoes over 48 hr to explore the coregulation of gene expression rhythms by the circadian clock and light, and compare these with the 24 hr rhythmic gene expression in the diurnal Aedes aegypti dengue vector mosquito. Results In time courses from An. gambiae head and body collected under light:dark cycle (LD) and constant dark (DD) conditions, we applied three algorithms that detect sinusoidal patterns and an algorithm that detects spikes in expression. This revealed across four experimental conditions 393 probes newly scored as rhythmic. These genes correspond to functions such as metabolic detoxification, immunity and nutrient sensing. This includes glutathione S-transferase GSTE5, whose expression pattern and chromosomal location are shared with other genes, suggesting shared chromosomal regulation; and pulsatile expression of the gene encoding CYP6M2, a cytochrome P450 that metabolizes pyrethroid insecticides. We explored the interaction of light and the circadian clock and highlight the regulation of odorant binding proteins (OBPs), important components of the olfactory system. We reveal that OBPs have unique expression patterns as mosquitoes make the transition from LD to DD conditions. We compared rhythmic expression between An. gambiae and Ae. aegypti heads collected under LD conditions using a single cosine fitting algorithm, and report distinct similarities and differences in the temporal regulation of genes involved in tRNA priming, the vesicular-type ATPase, olfaction and vision between the two species. Conclusions These data build on our previous analyses of time-of-day specific regulation of the An. gambiae transcriptome to reveal additional rhythmic genes, an

  19. Polymorphisms detected by random PCR distinguish between different chromosomal forms of Anopheles gambiae.

    PubMed Central

    Favia, G; Dimopoulos, G; della Torre, A; Touré, Y T; Coluzzi, M; Louis, C

    1994-01-01

    We have applied PCR amplification using random primers to distinguish between incipient species of the malaria vector Anopheles gambiae. Individuals belonging to three chromosomally characterized West African forms of this mosquito, which are important epidemiologically as they differ in vectorial capacity, were sampled both from laboratory stocks and from wild populations collected in three localities. The techniques used allowed for the unambiguous classification of the mosquitoes, providing a tool for rapid and efficient diagnosis, which previously relied on cytological examination of polytene chromosomes. Images PMID:7937947

  20. A Peroxidase/Dual Oxidase System Modulates Midgut Epithelial Immunity in Anopheles gambiae

    PubMed Central

    Kumar, Sanjeev; Molina-Cruz, Alvaro; Gupta, Lalita; Rodrigues, Janneth; Barillas-Mury, Carolina

    2012-01-01

    Extracellular matrices in diverse biological systems are crosslinked by dityrosine covalent bonds catalyzed by the peroxidase/oxidase system. We show that the Immunomodulatory Peroxidase (IMPer), an enzyme secreted by the mosquito Anopheles gambiae midgut, and dual oxidase (Duox) form a dityrosine network that decreases gut permeability to immune elicitors and protects the microbiota by preventing activation of epithelial immunity. It also provides a suitable environment for malaria parasites to develop within the midgut lumen without inducing nitric oxide synthase expression. Disruption of this barrier results in strong and effective pathogen-specific immune responses. PMID:20223948

  1. A peroxidase/dual oxidase system modulates midgut epithelial immunity in Anopheles gambiae.

    PubMed

    Kumar, Sanjeev; Molina-Cruz, Alvaro; Gupta, Lalita; Rodrigues, Janneth; Barillas-Mury, Carolina

    2010-03-26

    Extracellular matrices in diverse biological systems are cross-linked by dityrosine covalent bonds catalyzed by the peroxidase/oxidase system. We show that a peroxidase, secreted by the Anopheles gambiae midgut, and dual oxidase form a dityrosine network that decreases gut permeability to immune elicitors. This network protects the microbiota by preventing activation of epithelial immunity. It also provides a suitable environment for malaria parasites to develop within the midgut lumen without inducing nitric oxide synthase expression. Disruption of this barrier results in strong and effective pathogen-specific immune responses. PMID:20223948

  2. Enhancing Attraction of African Malaria Vectors to a Synthetic Odor Blend.

    PubMed

    Mweresa, Collins K; Mukabana, Wolfgang R; Omusula, Philemon; Otieno, Bruno; Van Loon, Joop J A; Takken, Willem

    2016-06-01

    The deployment of odor-baited tools for sampling and controlling malaria vectors is limited by a lack of potent synthetic mosquito attractants. A synthetic mixture of chemical compounds referred to as "the Mbita blend" (MB) was shown to attract as many host-seeking malaria mosquitoes as attracted to human subjects. We hypothesized that this effect could be enhanced by adding one or more attractive compounds to the blend. We tested changes in the capability of MB (ammonia + L-lactic acid + tetradecanoic acid +3-methyl-1-butanol + carbon dioxide) to attract host-seeking malaria mosquitoes by addition of selected dilutions of butyl-2-methylbutanoate (1:10,000), 2-pentadecanone (1:100), 1-dodecanol (1:10,000), and butan-1-amine (1:10,000,000). The experiments were conducted in semi-field enclosures and in a village in western Kenya. In semi-field enclosures, the attraction of Anopheles gambiae sensu stricto females to MB-baited traps was not enhanced by adding butyl-2-methylbutanoate. There was, however, an increase in the proportion of An. gambiae caught in traps containing MB augmented with the selected dilutions of butan-1-amine, 2-pentadecanone, and 1-dodecanol. When tested in the village, addition of butan-1-amine to MB enhanced catches of female An. gambiae sensu lato, An. funestus, and Culex mosquitoes. 1-Dodecanol increased attraction of An. gambiae s.l. to the MB, while addition of 2-pentadecanone improved trap catches of An. funestus and Culex mosquitoes. This study demonstrates the possibility of enhancing synthetic odor blends for trapping the malarial mosquitoes An. gambiae s.l. and An. funestus, as well as some culicine species. The findings provide promising results for the optimization and utilization of synthetic attractants for sampling and controlling major disease vectors. PMID:27349651

  3. Multilocus sequence analysis and rpoB sequencing of Mycobacterium abscessus (sensu lato) strains.

    PubMed

    Macheras, Edouard; Roux, Anne-Laure; Bastian, Sylvaine; Leão, Sylvia Cardoso; Palaci, Moises; Sivadon-Tardy, Valérie; Gutierrez, Cristina; Richter, Elvira; Rüsch-Gerdes, Sabine; Pfyffer, Gaby; Bodmer, Thomas; Cambau, Emmanuelle; Gaillard, Jean-Louis; Heym, Beate

    2011-02-01

    Mycobacterium abscessus, Mycobacterium bolletii, and Mycobacterium massiliense (Mycobacterium abscessus sensu lato) are closely related species that currently are identified by the sequencing of the rpoB gene. However, recent studies show that rpoB sequencing alone is insufficient to discriminate between these species, and some authors have questioned their current taxonomic classification. We studied here a large collection of M. abscessus (sensu lato) strains by partial rpoB sequencing (752 bp) and multilocus sequence analysis (MLSA). The final MLSA scheme developed was based on the partial sequences of eight housekeeping genes: argH, cya, glpK, gnd, murC, pgm, pta, and purH. The strains studied included the three type strains (M. abscessus CIP 104536(T), M. massiliense CIP 108297(T), and M. bolletii CIP 108541(T)) and 120 isolates recovered between 1997 and 2007 in France, Germany, Switzerland, and Brazil. The rpoB phylogenetic tree confirmed the existence of three main clusters, each comprising the type strain of one species. However, divergence values between the M. massiliense and M. bolletii clusters all were below 3% and between the M. abscessus and M. massiliense clusters were from 2.66 to 3.59%. The tree produced using the concatenated MLSA gene sequences (4,071 bp) also showed three main clusters, each comprising the type strain of one species. The M. abscessus cluster had a bootstrap value of 100% and was mostly compact. Bootstrap values for the M. massiliense and M. bolletii branches were much lower (71 and 61%, respectively), with the M. massiliense cluster having a fuzzy aspect. Mean (range) divergence values were 2.17% (1.13 to 2.58%) between the M. abscessus and M. massiliense clusters, 2.37% (1.5 to 2.85%) between the M. abscessus and M. bolletii clusters, and 2.28% (0.86 to 2.68%) between the M. massiliense and M. bolletii clusters. Adding the rpoB sequence to the MLSA-concatenated sequence (total sequence, 4,823 bp) had little effect on the

  4. Lyme borreliosis caused by diverse genospecies of Borrelia burgdorferi sensu lato in northeastern China.

    PubMed

    Ni, X-B; Jia, N; Jiang, B-G; Sun, T; Zheng, Y-C; Huo, Q-B; Liu, K; Ma, L; Zhao, Q-M; Yang, H; Wang, X; Jiang, J-F; Cao, W-C

    2014-08-01

    The variety of Borrelia burgdorferi sensu lato (B. burgdorferi) genospecies leads to distinction in clinical manifestations of Lyme borreliosis (LB). There are reports of LB clinical characteristics in China, where the B. burgdorferi genospecies in ticks and animal hosts are different from those in Europe and North America. During May to September in 2010 and 2011, all patients who had erythema migrans (EM, more than 5 cm in diameter) after a recent tick-bite, and sought medical care at Mudanjiang Forestry Central Hospital, Heilongjiang Province of northeastern China, were enrolled in the study. Specific PCR was used to determine the B. burgdorferi genospecies in the disseminated patients. Of 265 EM patients, B. burgdorferi DNA was detected in blood specimens from 15 of 55 disseminated patients. Sequence analyses of 5S-23S rRNA, flagellin, ospC, 16S rRNA and ospA genes revealed that 11 patients were infected with Borrelia garinii, three with Borrelia afzelii and one with Borrelia valaisiana-related genospecies. Among 15 patients, 40%, 13.3% and 13.3% manifested pruritus, pain and ulceration, respectively. Systemic symptoms, arthralgia or a swollen joint and lymphadenopathy were observed in 26.7%, 13.3% and 6.7% patients, respectively. In northeastern China, three genospecies of LB patients were detected. The B. burgdorferi genospecies identified in this study was predominantly B. garinii. A case infected with B. valaisiana-related genospecies was reported for the first time. PMID:24438159

  5. Trematode diversity in the freshwater snail Bithynia siamensis goniomphalos sensu lato from Thailand and Lao PDR.

    PubMed

    Kiatsopit, N; Sithithaworn, P; Kopolrat, K; Namsanor, J; Andrews, R H; Petney, T N

    2016-05-01

    In order to obtain a comprehensive understanding of trematode diversity in Bithynia siamensis goniomphalos sensu lato, the first intermediate host of the liver fluke Opisthorchis viverrini s.l., the prevalence of larval trematode species was investigated in different localities in Thailand and Lao People's Democratic Republic (Lao PDR). In Thailand, snail samples were collected from 29 localities in the nine provinces: Buri Ram, Surin, Chaiya Phum, Maha Sarakham, Khon Kaen, Kalasin, Mukdahan, Sakon Nakhon and Nakhon Phanom. In Lao PDR, snail samples were collected from 21 localities in Vientiane Province and six localities in Savannakhet Province. Snails were identified by standard morphological criteria and then examined for trematode infection using the cercarial shedding method. Twenty different types of cercariae were detected and identified, based on morphological criteria. Virgulate type 1 emerged as the most common cercaria, with an average prevalence of 10.90% (range 0.26-54.22%) in Thailand and 6.58% (range 1.15-89.77%) in Lao PDR. Opisthorchis viverrini s.l. cercariae were the fourth most common in Thailand, with an average prevalence of 1.59% (0.15-6.93), while in Lao PDR their prevalence was 0.96% (0.08-8.37). The high diversity of trematode cercariae observed in this study indicates that B. s. goniomphalos s.l. is highly susceptible to infection with a variety of trematode species. However, the role of non-opisthorchiid trematodes as fish-borne parasites in human health is not fully known and further molecular identification is required. PMID:25997613

  6. Genome size variation and incidence of polyploidy in Scrophulariaceae sensu lato from the Iberian Peninsula

    PubMed Central

    Castro, Mariana; Castro, Sílvia; Loureiro, João

    2012-01-01

    Background and aims In the last decade, genomic studies using DNA markers have strongly influenced the current phylogeny of angiosperms. Genome size and ploidy level have contributed to this discussion, being considered important characters in biosystematics, ecology and population biology. Despite the recent increase in studies related to genome size evolution and polyploidy incidence, only a few are available for Scrophulariaceae. In this context, we assessed the value of genome size, mostly as a taxonomic marker, and the role of polyploidy as a process of genesis and maintenance of plant diversity in Scrophulariaceae sensu lato in the Iberian Peninsula. Methodology Large-scale analyses of genome size and ploidy-level variation across the Iberian Peninsula were performed using flow cytometry. One hundred and sixty-two populations of 59 distinct taxa were analysed. A bibliographic review on chromosome counts was also performed. Principal results From the 59 sampled taxa, 51 represent first estimates of genome size. The majority of the Scrophulariaceae species presented very small to small genome sizes (2C ≤ 7.0 pg). Furthermore, in most of the analysed genera it was possible to use this character to separate several taxa, independently if these genera were homoploid or heteroploid. Also, some genome-related phenomena were detected, such as intraspecific variation of genome size in some genera and the possible occurrence of dysploidy in Verbascum spp. With respect to polyploidy, despite a few new DNA ploidy levels having been detected in Veronica, no multiple cytotypes have been found in any taxa. Conclusions This work contributed with important basic scientific knowledge on genome size and polyploid incidence in the Scrophulariaceae, providing important background information for subsequent studies, with several perspectives for future studies being opened. PMID:23240073

  7. Phylogeography of Rhipicephalus sanguineus sensu lato and its relationships with climatic factors.

    PubMed

    Zemtsova, Galina E; Apanaskevich, Dmitry A; Reeves, Will K; Hahn, Micah; Snellgrove, Alyssa; Levin, Michael L

    2016-06-01

    Brown dog ticks morphologically identifiable as Rhipicephalus sanguineus sensu lato, are distributed world-wide and their systematics is controversial. Results of genetic and reproductive compatibility studies of geographically distinct populations of R. sanguineus s.l. indicate that the R. sanguineus complex is paraphyletic. To further elucidate systematic relationships within R. sanguineus s.l. and geographic boundaries of its lineages, we conducted a phylogeographical study of 136 tick specimens from 23 countries. Voucher specimens were morphologically identified. A phylogenetic tree was constructed using concatenated partial mitochondrial 12S and 16S rDNA gene sequences and analyzed by the Neighbor-Joining method. A set of 19 bioclimatic variables within the WorldClim dataset were extracted and analyzed to assess correlations between distribution of R. sanguineus s.l. lineages and climatic variables. The following four branches are clearly recognized on the phylogenetic tree: R. sanguineus s.l.-tropical and temperate clades, R. leporis, and R. turanicus. DNA sequences of Rhipicephalus ticks from Israel differ from those of other groups. Strong association between geographical locations of major clades of R. sanguineus s.l. and temperature was identified. The tropical clade of R. sanguineus s.l. occupies areas with the annual mean temperature >20 °C, whereas the temperate clade is present in areas with the annual mean temperature <20 °C. Our results indicate that ticks in two closely related phylogenetic clades are adapted to different environmental conditions and support proposals for re-classification of R. sanguineus complex. Differences in R. sanguineus s.l. ecology and human/animal pathogens transmitted by different taxa of brown dog tick need to be studied. PMID:27003273

  8. Evolutionary Genomics of Borrelia burgdorferi sensu lato: Findings, Hypotheses, and the Rise of Hybrids

    PubMed Central

    Qiu, Wei-Gang; Martin, Che L.

    2014-01-01

    Borrelia burgdorferi sensu lato (B. burgdorferi s.l.), the group of bacterial species represented by Lyme Disease pathogens, has one of the most complex and variable genomic architectures among prokaryotes. Showing frequent recombination within and limited gene flow among geographic populations, the B. burgdorferi s.l. genomes provides an excellent window into the processes of bacterial evolution at both within- and between-population levels. Comparative analyses of B. burgdorferi s.l. genomes revealed a highly dynamic plasmid composition but a conservative gene repertoire. Gene duplication and loss as well as sequence variations at loci encoding surface-localized lipoproteins (e.g., the PF54 genes) are strongly associated with adaptive differences between species. There are a great many conserved intergenic spacer sequences that are candidates for cis-regulatory elements and non-coding RNAs. Recombination among coexisting strains occurs at a rate approximately three times the mutation rate. The coexistence of a large number of genomic groups within local B. burgdorferi s.l. populations may be driven by immune-mediated diversifying selection targeting major antigen loci as well as by adaptation to multiple host species. Questions remain regarding the ecological causes (e.g., climate change, host movements, or new adaptations) of the ongoing range expansion of B. burgdorferi s.l. and on the genomic variations associated with its ecological and clinical variability. Anticipating an explosive growth of the number of B. burgdorferi s.l. genomes sampled from both within and among species, we propose genome-based methods to test adaptive mechanisms and to identify molecular bases of phenotypic variations. Genome sequencing is also necessary to monitor the ongoing genetic admixture of previously isolated species and populations in North America and elsewhere. PMID:24704760

  9. Toxicity of Boswellia dalzielii (Burseraceae) Leaf Fractions Against Immature Stages of Anopheles gambiae (Giles) and Culex quinquefasciatus (Say) (Diptera: Culicidae).

    PubMed

    Younoussa, Lame; Nukenine, Elias Nchiwan; Esimone, Charles Okechukwu

    2016-01-01

    Mosquitoes are vectors of several human pathogens, and great attention has recently been placed on insecticides from plant-derived products, in search for mosquito control agents. This study, thus, investigated the potency of Boswellia dalzielii methanol leaf extract and its four fractions as mosquito ovicide, larvicide, and pupicide against Anopheles gambiae and Culex quinquefasciatus. The plant products were tested at the following concentrations: 125, 250, 500, 1000, and 2000 ppm on eggs and 312.5, 625, 1250, and 2500 ppm on the larvae and pupae of the mosquitoes. For results, hatchability of A. gambiae eggs was reduced to 5% with n-hexane fraction at 2000 ppm. Among the plant products tested, n-hexane fraction was most toxic against A. gambiae (LC50 = 385.9 ppm) and C. quinquefasciatus (LC50 = 3394.9 ppm). The n-hexane fraction of B. dalzielii might be used as a mosquitocidal agent in the breeding sites of A. gambiae and C. quinquefasciatus. PMID:27279752

  10. Shift in species composition in the Anopheles gambiae complex after implementation of long-lasting insecticidal nets in Dielmo, Senegal.

    PubMed

    Sougoufara, S; Harry, M; Doucouré, S; Sembène, P M; Sokhna, C

    2016-09-01

    Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the cornerstones of malaria vector control. However, the effectiveness of these control tools depends on vector ecology and behaviour, which also largely determine the efficacy of certain Anopheles mosquitoes (Diptera: Culicidae) as vectors. Malaria vectors in sub-Saharan Africa are primarily species of the Anopheles gambiae complex, which present intraspecific differences in behaviour that affect how they respond to vector control tools. The focus of this study is the change in species composition in the An. gambiae complex after the implementation of LLINs in Dielmo, Senegal. The main findings referred to dramatic decreases in the proportions of Anopheles coluzzii and An. gambiae after the introduction of LLINs, and an increase in the proportion of Anopheles arabiensis. Two years after LLINs were first introduced, An. arabiensis remained the most prevalent species and An. gambiae had begun to rebound. This indicated a need to develop additional vector control tools that can target the full range of malaria vectors. PMID:27058993

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  12. Situation Report--Australia, The Gambia, Papua and New Guinea, Rhodesia, Sri Lanka, Taiwan, Tanzania, Tonga, and Western Samoa.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in nine foreign countries are presented in these situation reports. Countries included are Australia, The Gambia, Papua and New Guinea, Rhodesia, Sri Lanka, Taiwan, Tanzania, Tonga, and Western Somoa. Information is provided under three topics, statistical information, general background information,…

  13. An Examination of Early Childhood Teacher Education in Four West African Nations: Ghana, Mali, Senegal, and the Gambia.

    ERIC Educational Resources Information Center

    Pagano, Alicia I.

    This paper examines opportunities and challenges in early childhood teacher education in Ghana, Mali, Senegal, and the Gambia. It reviews socioeconomic and political issues, current and emerging policies for early childhood and primary education, teacher preparation strategies, and examples of successful programs. Information was collected during…

  14. Function and composition of male accessory gland secretions in Anopheles gambiae: a comparison with other insect vectors of infectious diseases

    PubMed Central

    Baldini, Francesco; Gabrieli, Paolo; Rogers, David W.; Catteruccia, Flaminia

    2012-01-01

    Human malaria, a major public health burden in tropical and subtropical countries, is transmitted exclusively by the bite of a female Anopheles mosquito. Malaria control strategies aimed at inducing sexual sterility in natural vector populations are an attractive alternative to the use of insecticides. However, despite their importance as disease vectors, limited information is available on the molecular mechanisms regulating fertility in Anopheles mosquitoes. In the major malaria vector, An. gambiae, the full complement of sperm and seminal fluid required for a female’s lifelong egg production is obtained from a single mating event. This single mating has important consequences for the physiology and behavior of An. gambiae females: in particular, they become refractory to further insemination, and they start laying eggs. In other insects including Drosophila, similar post-copulatory changes are induced by seminal proteins secreted by the male accessory glands and transferred to the female during mating. In this review, we analyze the current state of knowledge on the function and characterization of male seminal proteins in An. gambiae, and provide a comparative assessment of the role of these male reproductive factors in other mosquito vectors of human disease in which female post-copulatory behavior has been studied. Knowledge of the factors and mechanisms regulating fertility in An. gambiae and other vectors can help the design of novel control strategies to fight the spread of disease. PMID:22943543

  15. Toxicity of Boswellia dalzielii (Burseraceae) Leaf Fractions Against Immature Stages of Anopheles gambiae (Giles) and Culex quinquefasciatus (Say) (Diptera: Culicidae)

    PubMed Central

    Younoussa, Lame; Nukenine, Elias Nchiwan; Esimone, Charles Okechukwu

    2016-01-01

    Mosquitoes are vectors of several human pathogens, and great attention has recently been placed on insecticides from plant-derived products, in search for mosquito control agents. This study, thus, investigated the potency of Boswellia dalzielii methanol leaf extract and its four fractions as mosquito ovicide, larvicide, and pupicide against Anopheles gambiae and Culex quinquefasciatus. The plant products were tested at the following concentrations: 125, 250, 500, 1000, and 2000 ppm on eggs and 312.5, 625, 1250, and 2500 ppm on the larvae and pupae of the mosquitoes. For results, hatchability of A. gambiae eggs was reduced to 5% with n-hexane fraction at 2000 ppm. Among the plant products tested, n-hexane fraction was most toxic against A. gambiae (LC50 = 385.9 ppm) and C. quinquefasciatus (LC50 = 3394.9 ppm). The n-hexane fraction of B. dalzielii might be used as a mosquitocidal agent in the breeding sites of A. gambiae and C. quinquefasciatus. PMID:27279752

  16. Assessment of Cognitive Abilities in Multiethnic Countries: The Case of the Wolof and Mandinka in the Gambia

    ERIC Educational Resources Information Center

    Jukes, Matthew C. H.; Grigorenko, Elena L.

    2010-01-01

    Background: The use of cognitive tests is increasing in Africa but little is known about how such tests are affected by the great ethnic and linguistic diversity on the continent. Aim: To assess ethnic and linguistic group differences in cognitive test performance in the West African country of the Gambia and to investigate the sources of these…

  17. Toxicity of six plant extracts and two pyridine alkaloids from Ricinus communis against the malaria vector Anopheles gambiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. Molecular basis of odor coding in the malaria vector mosquito Anopheles gambiae

    PubMed Central

    Wang, Guirong; Carey, Allison F.; Carlson, John R.; Zwiebel, Laurence J.

    2010-01-01

    A systematic functional analysis across much of the conventional Anopheles gambiae odorant receptor (AgOR) repertoire was carried out in Xenopus oocytes using two-electrode, voltage-clamp electrophysiology. The resulting data indicate that each AgOR manifests a distinct odor-response profile and tuning breadth. The large diversity of tuning responses ranges from AgORs that are responsive to a single or small number of odorants (specialists) to more broadly tuned receptors (generalists). Several AgORs were identified that respond robustly to a range of human volatiles that may play a critical role in anopheline host selection. AgOR responses were analyzed further by constructing a multidimensional odor space representing the relationships between odorants and AgOR responses. Within this space, the distance between odorants is related to both chemical class and concentration and may correlate with olfactory discrimination. This study provides a comprehensive overview of olfactory coding mechanisms of An. gambiae that ultimately may aid in fostering the design and development of olfactory-based strategies for reducing the transmission of malaria and other mosquito-borne diseases. PMID:20160092

  19. Impact of trehalose transporter knockdown on Anopheles gambiae stress adaptation and susceptibility to Plasmodium falciparum infection

    PubMed Central

    Liu, Kun; Dong, Yuemei; Huang, Yuzheng; Rasgon, Jason L.; Agre, Peter

    2013-01-01

    Anopheles gambiae is a major vector mosquito for Plasmodium falciparum, the deadly pathogen causing most human malaria in sub-Saharan Africa. Synthesized in the fat body, trehalose is the predominant sugar in mosquito hemolymph. It not only provides energy but also protects the mosquito against desiccation and heat stresses. Trehalose enters the mosquito hemolymph by the trehalose transporter AgTreT1. In adult female A. gambiae, AgTreT1 is predominantly expressed in the fat body. We found that AgTreT1 expression is induced by environmental stresses such as low humidity or elevated temperature. AgTreT1 RNA silencing reduces the hemolymph trehalose concentration by 40%, and the mosquitoes succumb sooner after exposure to desiccation or heat. After an infectious blood meal, AgTreT1 RNA silencing reduces the number of P. falciparum oocysts in the mosquito midgut by over 70% compared with mock-injected mosquitoes. These data reveal important roles for AgTreT1 in stress adaptation and malaria pathogen development in a major vector mosquito. Thus, AgTreT1 may be a potential target for malaria vector control. PMID:24101462

  20. Barriers to skilled birth attendance: a survey among mothers in rural Gambia.

    PubMed

    Lerberg, Priya Miriam; Sundby, Johanne; Jammeh, Abdou; Fretheim, Atle

    2014-03-01

    The objectives of this cross-sectional survey were to identify the most important barriers for use of skilled attendance during childbirth by women in rural Gambia. We also assessed information received during antenatal care, preparations made prior to childbirth, and experiences and perceptions that may influence the use of skilled birth attendance in rural Gambia. The most frequently stated barriers for giving birth in a health facility were not having enough time to go (75%), and lack of transport (29%). The majority of the women (83%) stated that they preferred having a health worker attending their childbirth. More than seventy percent of the participants gave birth attended by a traditional birth attendant, but only 27% had intended to give birth at home. Sixty-four percent had made advance arrangements for the childbirth. Only 22% were informed about expected time of birth during antenatal care. Our findings suggest that the participants hold the knowledge and motivation that is necessary if practices are to be changed. Interventions aiming at ensuring timely transport of women to health facilities seem key to increased use of skilled birth attendants. PMID:24796167

  1. Exploring Proteins in Anopheles gambiae Male and Female Antennae through MALDI Mass Spectrometry Profiling

    PubMed Central

    Dani, Francesca R.; Francese, Simona; Mastrobuoni, Guido; Felicioli, Antonio; Caputo, Beniamino; Simard, Frederic; Pieraccini, Giuseppe; Moneti, Gloriano; Coluzzi, Mario; della Torre, Alessandra; Turillazzi, Stefano

    2008-01-01

    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 aim of analysing expression of soluble proteins involved in olfaction perireceptor events. MALDI spectra obtained by direct profiling on single antennae and by the analysis of extracts, showed similar profiles, although spectra obtained through profiling had a richer ion population and higher signal to noise ratio. Male and female antennae showed distinct protein profiles. MALDI imaging experiments were also performed and differences were observed in the localization of some proteins. Two proteins were identified through high resolution measurement and top-down MS/MS experiments. A 8 kDa protein only present in the male antennae matched with an unannotated sequence of the An. gambiae genome, while the presence of odorant binding protein 9 (OBP-9) was confirmed through experiments of 2-DE, followed by MS and MS/MS analysis of digested spots. This work shows that MALDI MS profiling is a technique suitable for the analysis of proteins of small and medium MW in insect appendices, and allows obtaining data for several specimens which can be investigated for differences between groups. Proteins of interest can be identified through other complementary MS approaches. PMID:18665262

  2. Genetic Structure of a Local Population of the Anopheles gambiae Complex in Burkina Faso

    PubMed Central

    Markianos, Kyriacos; Bischoff, Emmanuel; Mitri, Christian; Guelbeogo, Wamdaogo M.; Gneme, Awa; Eiglmeier, Karin; Holm, Inge; Sagnon, N’Fale; Vernick, Kenneth D.; Riehle, Michelle M.

    2016-01-01

    Members of the Anopheles gambiae species complex are primary vectors of human malaria in Africa. Population heterogeneities for ecological and behavioral attributes expand and stabilize malaria transmission over space and time, and populations may change in response to vector control, urbanization and other factors. There is a need for approaches to comprehensively describe the structure and characteristics of a sympatric local mosquito population, because incomplete knowledge of vector population composition may hinder control efforts. To this end, we used a genome-wide custom SNP typing array to analyze a population collection from a single geographic region in West Africa. The combination of sample depth (n = 456) and marker density (n = 1536) unambiguously resolved population subgroups, which were also compared for their relative susceptibility to natural genotypes of Plasmodium falciparum malaria. The population subgroups display fluctuating patterns of differentiation or sharing across the genome. Analysis of linkage disequilibrium identified 19 new candidate genes for association with underlying population divergence between sister taxa, A. coluzzii (M-form) and A. gambiae (S-form). PMID:26731649

  3. Antennal-expressed ammonium transporters in the malaria vector mosquito Anopheles gambiae.

    PubMed

    Pitts, R Jason; Derryberry, Stephen L; Pulous, Fadi E; Zwiebel, Laurence J

    2014-01-01

    The principal Afrotropical malaria vector mosquito, Anopheles gambiae remains a significant threat to human health. In this anthropophagic species, females detect and respond to a range of human-derived volatile kairomones such as ammonia, lactic acid, and other carboxylic acids in their quest for blood meals. While the molecular underpinnings of mosquito olfaction and host seeking are becoming better understood, many questions remain unanswered. In this study, we have identified and characterized two candidate ammonium transporter genes, AgAmt and AgRh50 that are expressed in the mosquito antenna and may contribute to physiological and behavioral responses to ammonia, which is an important host kairomone for vector mosquitoes. AgAmt transcripts are highly enhanced in female antennae while a splice variant of AgRh50 appears to be antennal-specific. Functional expression of AgAmt in Xenopus laevis oocytes facilitates inward currents in response to both ammonium and methylammonium, while AgRh50 is able to partially complement a yeast ammonium transporter mutant strain, validating their conserved roles as ammonium transporters. We present evidence to suggest that both AgAmt and AgRh50 are in vivo ammonium transporters that are important for ammonia sensitivity in An. gambiae antennae, either by clearing ammonia from the sensillar lymph or by facilitating sensory neuron responses to environmental exposure. Accordingly, AgAmt and AgRh50 represent new and potentially important targets for the development of novel vector control strategies. PMID:25360676

  4. Analysis of the metabolome of Anopheles gambiae mosquito after exposure to Mycobacterium ulcerans

    PubMed Central

    Hoxmeier, J. Charles; Thompson, Brice D.; Broeckling, Corey D.; Small, Pamela; Foy, Brian D.; Prenni, Jessica; Dobos, Karen M.

    2015-01-01

    Infection with Mycobacterium ulcerans causes Buruli Ulcer, a neglected tropical disease. Mosquito vectors are suspected to participate in the transmission and environmental maintenance of the bacterium. However, mechanisms and consequences of mosquito contamination by M. ulcerans are not well understood. We evaluated the metabolome of the Anopheles gambiae mosquito to profile the metabolic changes associated with bacterial colonization. Contamination of mosquitoes with live M. ulcerans bacilli results in disruptions to lipid metabolic pathways of the mosquito, specifically the utilization of glycerolipid molecules, an affect that was not observed in mosquitoes exposed to dead M. ulcerans. These results are consistent with aberrations of lipid metabolism described in other mycobacterial infections, implying global host-pathogen interactions shared across diverse saprophytic and pathogenic mycobacterial species. This study implicates features of the bacterium, such as the putative M. ulcerans encoded phospholipase enzyme, which promote virulence, survival, and active adaptation in concert with mosquito development, and provides significant groundwork for enhanced studies of the vector-pathogen interactions using metabolomics profiling. Lastly, metabolic and survival data suggest an interaction which is unlikely to contribute to transmission of M. ulcerans by A. gambiae and more likely to contribute to persistence of M. ulcerans in waters cohabitated by both organisms. PMID:25784490

  5. Regulation of Anopheles gambiae male accessory gland genes influences postmating response in female.

    PubMed

    Dottorini, Tania; Persampieri, Tania; Palladino, Pietro; Baker, Dean A; Spaccapelo, Roberta; Senin, Nicola; Crisanti, Andrea

    2013-01-01

    In Drosophila, the accessory gland proteins (Acps) secreted from the male accessory glands (MAGs) and transferred along with sperm into the female reproductive tract have been implicated in triggering postmating behavioral changes, including refractoriness to subsequent mating and propensity to egg laying. Recently, Acps have been found also in Anopheles, suggesting similar functions. Understanding the mechanisms underlying transcriptional regulation of Acps and their functional role in modulating Anopheles postmating behavior may lead to the identification of novel vector control strategies to reduce mosquito populations. We identified heat-shock factor (HSF) binding sites within the Acp promoters of male Anopheles gambiae and discovered three distinct Hsf isoforms; one being significantly up-regulated in the MAGs after mating. Through genome-wide transcription analysis of Hsf-silenced males, we observed significant down-regulation in 50% of the Acp genes if compared to control males treated with a construct directed against an unrelated bacterial sequence. Treated males retained normal life span and reproductive behavior compared to control males. However, mated wild-type females showed a ∼46% reduction of egg deposition rate and a ∼23% reduction of hatching rate (∼58% combined reduction of progeny). Our results highlight an unsuspected role of HSF in regulating Acp transcription in A. gambiae and provide evidence that Acp down-regulation in males leads a significant reduction of progeny, thus opening new avenues toward the development of novel vector control strategies. PMID:22997226

  6. Genetic Structure of a Local Population of the Anopheles gambiae Complex in Burkina Faso.

    PubMed

    Markianos, Kyriacos; Bischoff, Emmanuel; Mitri, Christian; Guelbeogo, Wamdaogo M; Gneme, Awa; Eiglmeier, Karin; Holm, Inge; Sagnon, N'Fale; Vernick, Kenneth D; Riehle, Michelle M

    2016-01-01

    Members of the Anopheles gambiae species complex are primary vectors of human malaria in Africa. Population heterogeneities for ecological and behavioral attributes expand and stabilize malaria transmission over space and time, and populations may change in response to vector control, urbanization and other factors. There is a need for approaches to comprehensively describe the structure and characteristics of a sympatric local mosquito population, because incomplete knowledge of vector population composition may hinder control efforts. To this end, we used a genome-wide custom SNP typing array to analyze a population collection from a single geographic region in West Africa. The combination of sample depth (n = 456) and marker density (n = 1536) unambiguously resolved population subgroups, which were also compared for their relative susceptibility to natural genotypes of Plasmodium falciparum malaria. The population subgroups display fluctuating patterns of differentiation or sharing across the genome. Analysis of linkage disequilibrium identified 19 new candidate genes for association with underlying population divergence between sister taxa, A. coluzzii (M-form) and A. gambiae (S-form). PMID:26731649

  7. Species abundance and insecticide resistance of Anopheles gambiae in selected areas of Ghana and Burkina Faso.

    PubMed

    Yawson, A E; McCall, P J; Wilson, M D; Donnelly, M J

    2004-12-01

    The Ghanaian National Malaria Control Programme has prioritized insecticide-treated materials as a key strategy for malaria control. We report on a survey of the distribution of the molecular forms of Anopheles gambiae Giles (Diptera: Culicidae) and insecticide resistance (the kdr mutation), carried out by sampling mosquitoes from 11 locations in Ghana and one additional site in Burkina Faso. The molecular M and S forms of An. gambiae were found to occur in sympatry in southern Ghana. The S form predominated throughout its distribution in the coastal savannah, except at one location in the strand and mangrove zone where rice was cultivated. The M form was the only form collected in northern Ghana and was the predominant form (97.5%) in Burkina Faso. No M/S hybrids were detected. The kdr mutation was observed at very high frequencies (98-100%) within the S form but reached a maximum of only 3.38% in the M form in one population at an irrigation scheme in the Ghanaian coastal savannah zone. PMID:15642004

  8. A reliable morphological method to assess the age of male Anopheles gambiae

    PubMed Central

    Huho, Bernadette J; Ng'habi, Kija R; Killeen, Gerry F; Nkwengulila, Gamba; Knols, Bart GJ; Ferguson, Heather M

    2006-01-01

    Background Release of genetically-modified (GM) or sterile male mosquitoes for malaria control is hampered by inability to assess the age and mating history of free-living male Anopheles. Methods Age and mating-related changes in the reproductive system of male Anopheles gambiae were quantified and used to fit predictive statistical models. These models, based on numbers of spermatocysts, relative size of sperm reservoir and presence/absence of a clear area around the accessory gland, were evaluated using an independent sample of mosquitoes whose status was blinded during the experiment. Results The number of spermatocysts in male testes decreased with age, and the relative size of their sperm reservoir increased. The presence of a clear area around accessory glands was also linked to age and mating status. A quantitative model was able to categorize males from the blind trial into age groups of young (≤ 4 days) and old (> 4 days) with an overall efficiency of 89%. Using the parameters of this model, a simple table was compiled that can be used to predict male age. In contrast, mating history could not be reliably assessed as virgins could not be distinguished from mated males. Conclusion Simple assessment of a few morphological traits which are easily collected in the field allows accurate age-grading of male An. gambiae. This simple, yet robust, model enables evaluation of demographic patterns and mortality in wild and released males in populations targeted by GM or sterile male-based control programmes. PMID:16872516

  9. Treponemal infection and the outcome of pregnancy in a rural area of The Gambia, west Africa.

    PubMed

    Greenwood, A M; D'Alessandro, U; Sisay, F; Greenwood, B M

    1992-10-01

    Of 826 pregnant women studied in a rural area of The Gambia, 77 (9.3%) were seropositive for a treponemal infection (positive rapid plasma reagin [RPR] and Treponema pallidum hemagglutination [TPHA] test). The perinatal death rate recorded prospectively in babies of 77 seropositive women (39.0/1000 births) was less than that among babies of 720 seronegative women (77.6/1000 births; odds ratio, 0.48; 95% confidence interval, 0.15-1.57). No increase in mortality or morbidity was found among the children of 39 seropositive women compared with the children of 39 control women. Seropositivity was found in only 20 (1.1%) of 1872 children less than 14 years old residing in the same community. The finding that the babies of rural Gambian women seropositive for syphilis are not at risk of early death is of importance in determining the priority that should be given to establishing antenatal screening programs in The Gambia and neighboring communities. PMID:1527421

  10. Household concentrations and exposure of children to particulate matter from biomass fuels in The Gambia

    PubMed Central

    Dionisio, Kathie L; Howie, Stephen RC; Dominici, Francesca; Fornace, Kimberly M; Spengler, John D; Adegbola, Richard A; Ezzati, Majid

    2012-01-01

    Particulate matter (PM) is an important metric for studying the health effects of household air pollution. There are limited data on PM exposure for children in homes that use biomass fuels, and no previous study has used direct measurement of personal exposure in children younger than 5 years of age. We estimated PM2.5 exposure for 1,266 children in The Gambia by applying the cookhouse PM2.5-CO relationship to the child’s CO exposure. Using this indirect method, mean PM2.5 exposure for all subjects was 135 ± 38 μg/m3; 25% of children had exposures of 151 μg/m3 or higher. Indirectly-estimated exposure was highest among children who lived in homes that used firewood (collected or purchased) as their main fuel (144 μg/m3) compared to those who used charcoal (85 μg/m3). To validate the indirect method, we also directly measured PM2.5 exposure on 31 children. Mean exposure for this validation dataset was 65 ± 41 μg/m3 using actual measurement and 125 ± 54 μg/m3 using the indirect method based on CO exposure. The correlation coefficient between direct measurements and indirect estimates was 0.01. Children in The Gambia have relatively high PM2.5 exposure. There is a need for simple methods that can directly measure PM2.5 exposure in field studies. PMID:22304223

  11. Ecophysiology of Anopheles gambiae s.l.: Persistence in the Sahel

    PubMed Central

    Huestis, Diana L.; Lehmann, Tovi

    2014-01-01

    The dry-season biology of malaria vectors is poorly understood, especially in arid environments when no surface waters are available for several months, such as during the dry season in the Sahel. Here we reappraise results on the dry-season physiology of members of the Anopheles gambiae s.l. complex in the broad context of dormancy in insects and especially in mosquitoes. We examine evidence on seasonal changes in reproduction, metabolism, stress tolerance, nutrition, molecular regulation, and environmental conditions and determine if the current results are compatible with dry-season diapause (aestivation) as the primary strategy for persistence throughout the dry season in the Sahel. In the process, we point out critical gaps in our knowledge that future studies can fill. We find compelling evidence that members of the An. gambiae s.l. complex undergo a form of aestivation during the Sahelian dry season by shifting energetic resources away from reproduction and towards increased longevity. Considering the differences between winter at temperate latitudes, which entails immobility of the insect and hence reliance on physiological solutions, as opposed to the Sahelian dry season, which restricts reproduction exclusively, we propose that behavioral changes play an important role in complementing physiological changes in this strategy. PMID:24933461

  12. Comparative evaluation of systemic drugs for their effects against Anopheles gambiae.

    PubMed

    Butters, Matthew P; Kobylinski, Kevin C; Deus, Kelsey M; da Silva, Ines Marques; Gray, Meg; Sylla, Massamba; Foy, Brian D

    2012-01-01

    Laboratory and field studies have shown that ivermectin, a drug that targets invertebrate ligand-gated ion channels (LGICs), is potently active against Anopheles spp. mosquitoes at concentrations present in human blood after standard drug administrations; thus ivermectin holds promise as a mass human-administered endectocide that could help suppress malaria parasite transmission. We evaluated other systemic LGIC-targeting drugs for their activities against the African malaria vector Anopheles gambiae using in vitro blood feeding assays. Eprinomectin, selamectin, moxidectin, and N-tert-butyl nodulisporamide were evaluated as potentially systemic drugs having similar modes of action to ivermectin; all primarily are agonists of invertebrate glutamate-gated chloride ion channels. Additionally, nitenpyram and spinosad were evaluated as systemic drugs that primarily work as agonists of nicotinic acetylcholine receptor channels. Only eprinomectin killed An. gambiae at concentrations that were comparable to ivermectin. At sub-lethal doses, nitenpyram and moxidectin marginally affected mosquito re-blood feeding ability. The macrocyclic lactones, particularly eprinomectin, caused significantly increased knockdown and significantly inhibited recovery in blood fed females. These data are a first step in evaluating drugs that might be eventually combined with, or substituted for ivermectin for future malaria parasite transmission control. PMID:22019935

  13. The STAT pathway mediates late phase immunity against Plasmodium in the mosquito Anopheles gambiae

    PubMed Central

    Gupta, Lalita; Molina-Cruz, Alvaro; Kumar, Sanjeev; Rodrigues, Janneth; Dixit, Rajnikant; Zamora, Rodolfo E.; Barillas-Mury, Carolina

    2009-01-01

    The STAT family of transcription factors activate expression of immune system genes in vertebrates. The ancestral STAT gene (AgSTAT-A) appears to have duplicated in the mosquito Anopheles gambiae, giving rise to a second intronless STAT gene (AgSTAT-B), which we show regulates AgSTAT-A expression in adult females. AgSTAT-A participates in the transcriptional activation of nitric oxide synthase (NOS) in response to bacterial and plasmodial infection. Activation of this pathway, however, is not essential for mosquitoes to survive a bacterial challenge. AgSTAT-A silencing reduces the number of early Plasmodium oocysts in the midgut, but nevertheless enhances the overall infection by increasing oocyst survival. Silencing of SOCS, a STAT suppressor, has the opposite effect, reducing Plasmodium infection by increasing NOS expression. Chemical inhibition of mosquito NOS activity after oocyte formation increases oocyte survival. Thus, the AgSTAT-A pathway mediates a late phase anti-plasmodial response that reduces oocyst survival in An. gambiae. PMID:19454353

  14. The STAT pathway mediates late-phase immunity against Plasmodium in the mosquito Anopheles gambiae.

    PubMed

    Gupta, Lalita; Molina-Cruz, Alvaro; Kumar, Sanjeev; Rodrigues, Janneth; Dixit, Rajnikant; Zamora, Rodolfo E; Barillas-Mury, Carolina

    2009-05-01

    The STAT family of transcription factors activates expression of immune system genes in vertebrates. The ancestral STAT gene (AgSTAT-A) appears to have duplicated in the mosquito Anopheles gambiae, giving rise to a second intronless STAT gene (AgSTAT-B), which we show regulates AgSTAT-A expression in adult females. AgSTAT-A participates in the transcriptional activation of nitric oxide synthase (NOS) in response to bacterial and plasmodial infection. Activation of this pathway, however, is not essential for mosquitoes to survive a bacterial challenge. AgSTAT-A silencing reduces the number of early Plasmodium oocysts in the midgut, but nevertheless enhances the overall infection by increasing oocyst survival. Silencing of SOCS, a STAT suppressor, has the opposite effect, reducing Plasmodium infection by increasing NOS expression. Chemical inhibition of mosquito NOS activity after oocyte formation increases oocyte survival. Thus, the AgSTAT-A pathway mediates a late-phase antiplasmodial response that reduces oocyst survival in A. gambiae. PMID:19454353

  15. A rollercoaster of policy shifts: Global trends and reproductive health policy in The Gambia

    PubMed Central

    Sundby, Johanne

    2014-01-01

    Global trends influence strategies for health-care delivery in low- and middle-income countries. A drive towards uniformity in the design and delivery of healthcare interventions, rather than solid local adaptations, has come to dominate global health policies. This study is a participatory longitudinal study of how one country in West Africa, The Gambia, has responded to global health policy trends in maternal and reproductive health, based on the authors’ experience working as a public health researcher within The Gambia over two decades. The paper demonstrates that though the health system is built largely upon the principles of a decentralised and governed primary care system, as delineated in the Alma-Ata Declaration, the more recent policies of The Global Fund to Fight HIV/AIDS, Tuberculosis, and Malaria and the GAVI Alliance have had a major influence on local policies. Vertically designed health programmes have not been easily integrated with the existing system, and priorities have been shifted according to shifting donor streams. Local absorptive capacity has been undermined and inequalities exacerbated within the system. This paper problematises national actors’ lack of ability to manoeuvre within this policy context. The authors’ observations of the consequences in the field over time evoke many questions that warrant discussion, especially regarding the tension between local state autonomy and the donor-driven trend towards uniformity and top–down priority setting. PMID:25203251

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

    PubMed

    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. PMID:25283802

  17. Trypanosoma (Nannomonas) godfreyi sp. nov. from tsetse flies in The Gambia: biological and biochemical characterization.

    PubMed

    McNamara, J J; Mohammed, G; Gibson, W C

    1994-11-01

    We provide evidence from isoenzyme analysis, hybridization with repetitive DNA probes, behavioural studies and morphometrics that 4 trypanosome isolates from Glossina morsitans submorsitans in The Gambia constitute a new species now named Trypanosoma (Nannomonas) godfreyi. The bloodstream trypomastigotes of T. (N.) godfreyi are relatively small with a mean length of 13.7 microns (range: 9.1-21.8 microns) and a mean width of 1.65 microns (range: 0.65-2.69 microns). There is no free flagellum and the marginal kinetoplast is subterminal to a rounded posterior end; the undulating membrane is usually conspicuous. As with other Nannomonas, T. godfreyi developed in the midgut and proboscis of Glossina and infections matured in 21-28 days in laboratory G.m. morsitans. In The Gambia the normal vertebrate host appears to be the warthog, Phacochoerus aethiopicus, although elsewhere other wild and domestic suids may also be implicated in the life-cycle. T. godfreyi was identified unequivocally using a 380 bp DNA probe specific for a major genomic repeat sequence; its isoenzyme profile distinguished it clearly from T. simiae and three strain groups of T. congolense: savannah, riverine-forest and kilifi. PMID:7800418

  18. Aquaporin water channel AgAQP1 in the malaria vector mosquito Anopheles gambiae during blood feeding and humidity adaptation

    PubMed Central

    Liu, Kun; Tsujimoto, Hitoshi; Cha, Sung-Jae; Agre, Peter; Rasgon, Jason L.

    2011-01-01

    Altered patterns of malaria endemicity reflect, in part, changes in feeding behavior and climate adaptation of mosquito vectors. Aquaporin (AQP) water channels are found throughout nature and confer high-capacity water flow through cell membranes. The genome of the major malaria vector mosquito Anopheles gambiae contains at least seven putative AQP sequences. Anticipating that transmembrane water movements are important during the life cycle of A. gambiae, we identified and characterized the A. gambiae aquaporin 1 (AgAQP1) protein that is homologous to AQPs known in humans, Drosophila, and sap-sucking insects. When expressed in Xenopus laevis oocytes, AgAQP1 transports water but not glycerol. Similar to mammalian AQPs, water permeation of AgAQP1 is inhibited by HgCl2 and tetraethylammonium, with Tyr185 conferring tetraethylammonium sensitivity. AgAQP1 is more highly expressed in adult female A. gambiae mosquitoes than in males. Expression is high in gut, ovaries, and Malpighian tubules where immunofluorescence microscopy reveals that AgAQP1 resides in stellate cells but not principal cells. AgAQP1 expression is up-regulated in fat body and ovary by blood feeding but not by sugar feeding, and it is reduced by exposure to a dehydrating environment (42% relative humidity). RNA interference reduces AgAQP1 mRNA and protein levels. In a desiccating environment (<20% relative humidity), mosquitoes with reduced AgAQP1 protein survive significantly longer than controls. These studies support a role for AgAQP1 in water homeostasis during blood feeding and humidity adaptation of A. gambiae, a major mosquito vector of human malaria in sub-Saharan Africa. PMID:21444767

  19. Intraspecific chromosomal polymorphism in the Anopheles gambiae complex as a factor affecting malaria transmission in the Kisumu area of Kenya.

    PubMed

    Petrarca, V; Beier, J C

    1992-02-01

    The paracentric inversion polymorphisms of Anopheles gambiae and An. arabiensis populations in the Kisumu area of western Kenya were studied in relation to parameters of Plasmodium falciparum transmission. Anopheles gambiae (n = 1,387) was polymorphic for inversions b on chromosomal arm 2R and a on arm 2L, with frequencies of the inverted arrangements of 17% and 43%, respectively. Anopheles arabiensis (n = 484) was polymorphic for inversion b on chromosomal arm 2R and a on 3R, with frequencies of the inverted arrangements of 58% and 5%, respectively. Observed karyotypic frequencies did not deviate from Hardy-Weinberg equilibrium, indicating a condition of panmixia (i.e., random mating) for both species. The overall degree of intraspecific polymorphism was low, confirming findings from other zones of East Africa. No significant differences in inversion frequencies of either An. gambiae or An. arabiensis were observed, either between collecting sites or between similar sampling periods of consecutive years. At the same time, a stable, significant two-fold difference in Plasmodium infection rates was detected among An. gambiae carriers of different inversion karyotypes on chromosome 2. A significant non-uniform distribution of human- and bovid-fed specimens was also detected among the carriers of different 2Rb inversion karyotypes in indoor resting An. arabiensis. Relationships among inversion karyotypes of the two major malaria vectors in the An. gambiae complex and key factors affecting malaria transmission intensity emphasize that intraspecific variation could contribute significantly to the diversity and stability of malaria vectorial systems in Africa. PMID:1539757

  20. 20-Years of Population-Based Cancer Registration in Hepatitis B and Liver Cancer Prevention in The Gambia, West Africa

    PubMed Central

    Bah, Ebrima; Carrieri, Maria Patrizia; Hainaut, Pierre; Bah, Yusupha; Nyan, Ousman; Taal, Makie

    2013-01-01

    Background The Gambia Hepatitis Intervention Study (GHIS) was designed as a randomised control trial of infant hepatitis B vaccination applied to public health policy, with the main goal of preventing primary liver cancer later in adult life in The Gambia. To that effect, the National Cancer Registry of The Gambia (NCR), a population-based cancer registry (PBCR), was established in 1986 to actively collect data on all cancer diagnosis nation-wide. We extracted 20-years (1990-2009) of data to assess for the first time, the evolution of the most common cancers, also describe and demonstrate the role of the PBCR in a hepatitis B and liver cancer prevention programme in this population. Methods and Findings We estimated Age-Standardised Incidence Rates (ASR (W)) of the most common cancers registered during the period by gender. The registration period was divided into four 5-year intervals and incidence rates were estimated for each interval. The most common cancers in males were liver, prostate, lung plus bronchus, non-Hodgkin lymphoma (NHL) and stomach, accounting for 60%, 5%, 4%, 5% and 3%, respectively. Similarly, cancers of the cervix uteri, liver, breast and NHL, were the most common in females, accounting for 33%, 24%, 11% and 4% of the female cancers, respectively. Conclusions Cancer incidence has remained relatively stable over time, but as shown elsewhere in sub-Saharan Africa the disease is a threat in The Gambia. The infection related cancers which are mostly preventable (HBV in men and HPV/HIV in women) were the most common. At the moment the data is not enough to detect an effect of hepatitis B vaccination on liver cancer incidence in The Gambia. However, we observed that monitoring case occurrence through PBCR is a key public health pre-requisite for rational planning and implementation of targeted interventions for improving the health of the population. PMID:24098724

  1. Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon

    PubMed Central

    Chouaibou, Mouhamadou; Simard, Frédéric; Chandre, Fabrice; Etang, Josiane; Darriet, Frédéric; Hougard, Jean-Marc

    2006-01-01

    Background Recent field studies indicated that insecticide-treated bednets (ITNs) maintain their efficacy despite a high frequency of the knock-down resistance (kdr) gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. Methods Bifenthrin was used in this experiment because it is considered a promising candidate for bednets impregnation. Nets were treated at 50 mg/m2, a dose that has high insecticidal activity on kdr mosquitoes and at 5 mg/m2, a dose that kills 95% of susceptible mosquitoes under laboratory conditions with 3 minutes exposure. Bednets were holed to mimic physical damage. The trial was conducted in three experimental huts from Pitoa, North-Cameroon where Anopheles gambiae displays metabolic resistance and cohabits with An. funestus. Results Bifenthrin at 50 mg/m2 significantly reduced anophelines' entry rate (>80%). This was not observed at 5 mg/m2. Both treatments increased exophily in An. gambiae, and to a lesser extent in An. funestus. With bifenthrin at high dosage, over 60% reduction in blood feeding and 75–90% mortality rates were observed in both vectors. Despite presence of holes, only a single An. gambiae and two An. funestus females were collected inside the treated net, and all were found dead. The same trends were observed with low dosage bifenthrin though in most cases, no significant difference was found with the untreated control net. Conclusion Bifenthrin-impregnated bednets at 50 mg/m2 were efficient in the reduction of human-vector contact in Pitoa. Considerable personal protection was gained against An. funestus and metabolic pyrethroid resistant An. gambiae populations. PMID:16961938

  2. Borrelia burgdorferi sensu lato infection pressure shapes innate immune gene evolution in natural rodent populations across Europe

    PubMed Central

    Tschirren, Barbara

    2015-01-01

    Although parasite-mediated selection is assumed to be the main driver of immune gene evolution, empirical evidence that parasites induce allele frequency changes at host immune genes in time and/or space remains scarce. Here, I show that the frequency of a protective gene variant of the innate immune receptor Toll-like receptor 2 in natural bank vole (Myodes glareolus) populations is positively associated with the strength of Borrelia burgdorferi sensu lato infection risk across the European continent. Thereby, this study provides rare evidence for the role of spatially variable infection pressures in moulding the vertebrate immune system. PMID:26018834

  3. Borrelia burgdorferi sensu lato infection pressure shapes innate immune gene evolution in natural rodent populations across Europe.

    PubMed

    Tschirren, Barbara

    2015-05-01

    Although parasite-mediated selection is assumed to be the main driver of immune gene evolution, empirical evidence that parasites induce allele frequency changes at host immune genes in time and/or space remains scarce. Here, I show that the frequency of a protective gene variant of the innate immune receptor Toll-like receptor 2 in natural bank vole (Myodes glareolus) populations is positively associated with the strength of Borrelia burgdorferi sensu lato infection risk across the European continent. Thereby, this study provides rare evidence for the role of spatially variable infection pressures in moulding the vertebrate immune system. PMID:26018834

  4. Filling the Gap 115 Years after Ronald Ross: The Distribution of the Anopheles coluzzii and Anopheles gambiae s.s from Freetown and Monrovia, West Africa

    PubMed Central

    de Souza, Dziedzom K.; Koudou, Benjamin G.; Bolay, Fatorma K.; Boakye, Daniel A.; Bockarie, Moses J.

    2013-01-01

    It was in Freetown, Sierra Leone, that the malaria mosquito Anopheles coastalis, now known as Anopheles gambiae, was first discovered as the vector of malaria, in 1899. That discovery led to a pioneering vector research in Sierra Leone and neighbouring Liberia, where mosquito species were extensively characterized. Unfortunately, the decade long civil conflicts of the 1990s, in both countries, resulted in a stagnation of the once vibrant research on disease vectors. This paper attempts to fill in some of the gaps on what is now known of the distribution of the sibling species of the An. gambiae complex, and especially the An. coluzzii and An. gambiae s.s, formerly known as the An. gambiae molecular M and S forms respectively, in the cities of Freetown and Monrovia. PMID:23741429

  5. [Borrelia burgdorferi sensu lato in ixodid ticks from Ostrava slag heaps].

    PubMed

    Jarosová, V; Rudolf, I; Halouzka, J; Hubálek, Z

    2009-04-01

    In 2005 and 2006, Ixodes ricinus ticks were collected on two slag (waste rock) heaps from coal mines in the Ostrava area (North Moravia/Silesia, Czech Republic), Oskar (site A) and Emma (site B), partially covered by vegetation including trees, and at a control forest site near Hlucín (site C). The mean numbers of L. ricinus nymphs and imagoes flagged per person-hour were high: 35.3 nymphs and 12.7 imagoes, at site A, 23.3 and 26.0, respectively, at site B, and 25.4 and 16.8, respectively, at control site C. Using dark-field microscopy, 100 nymphs and 100 imagoes (50 females and 50 males) from each site were examined for borreliae. The mean prevalence rates of Borrelia burgdorferi sensu lato in nymphs and imagoes were 10.0% and 12.0%, respectively, at site A, 10.0% and 24.0%, respectively, at site B, and 13.0% and 17.0%, respectively, at site C. Differences in the prevalence of borreliae in nymphal and adult ticks from the slag heaps and control site were insignificant, but adult ticks from site B compared to site A contained borreliae significantly more frequently. The mean numbers of nymphs and imagoes infected with borreliae flagged per person-hour were 3.3 and 1.2, respectively at site A, 1.5 and 2.9, respectively, at site B, and 3.1 and 2.6, respectively, at site C. Isolation experiments for borreliae were carried out only in 16 ticks containing higher numbers of borreliae, with eight of these being culture-positive. The cultured borreliae were identified by PCR-RFLP as B. garinii (3 isolates: two from site B, one from site C), B. afzelii (4 isolates: one from site A, three from site B) and B. burgdorferi s.s. (one isolate from site A). Surprisingly, the results suggest that slag heaps, when covered by woody vegetation and frequented by humans, could theoretically pose roughly the same LB transmission risk to humans as common forest biotopes. PMID:19526923

  6. Computer-Assisted In Sensu Exposure for Posttraumatic Stress Disorder: Development and Evaluation

    PubMed Central

    Priebe, Kathlen; Deuschel, Tilman; Schüller, Martin; Schriner, Friederike; Kleindienst, Nikolaus; Ludäscher, Petra; Schmahl, Christian; Bohus, Martin

    2016-01-01

    Background Dissociative states during psychotherapy sessions reduce the benefit of exposure-based therapy for posttraumatic stress disorder (PTSD). Thus, in evidence-based therapeutic programs such as dialectical behavior therapy for PTSD (DBT-PTSD), therapists apply specific antidissociative skills to reduce dissociative features during in sensu exposure. In addition to therapist-guided sessions, exposure protocols often require that the patients listen to audio recordings of exposure sessions in self-management. The problem of how to prevent dissociative features during such self-administered exposure exercises has not been resolved yet. Hence, we developed the computer program MORPHEUS that supports the application of self-administered exposure exercises. MORPHEUS continuously monitors the level of dissociative states and offers state-related antidissociative skills. Objective This study sought to examine the acceptance and feasibility of the MORPHEUS program. Methods Patients who underwent 12 weeks of residential DBT-PTSD treatment used MORPHEUS during exposure exercises in self-management. After the treatment, they filled out evaluation questionnaires. Results In sum, 26 patients receiving a 12-week standard DBT-PTSD program participated in this study; 2 participants could not be analyzed because of missing data. All the patients used MORPHEUS as often as it was required according to the DBT-PTSD treatment (2 to 5 times a week). The overall acceptance and feasibility as rated by the patients was high: for example, patients found the skills useful to block dissociation (mean 4.24 on a scale from 0 to 5, SD 0.24) and stated that they would use the program again (mean 4.72 on a scale from 0 to 5, SD 0.11). Furthermore, patients indicated that they would recommend MORPHEUS to a friend (mean 4.44 on a scale from 0 to 5, SD 0.12). In 82% (32/39) of the cases, the use of antidissociative skills was related to a decrease in dissociation. In 18% (5/39), dissociation

  7. Salmonella enterica Serotype Gambia with CTX-M-3 and armA Resistance Markers: Nosocomial Infections with a Fatal Outcome▿

    PubMed Central

    Moissenet, D.; Weill, F.-X.; Arlet, G.; Harrois, D.; Girardet, J. P.; Vu-Thien, H.

    2011-01-01

    We report two cases of bacteremia caused by the Salmonella enterica serotype Gambia in our children's hospital, with one fatal outcome. The isolates showed indistinguishable genotypes and infrequent resistance markers: CTX-M-3 extended-spectrum β-lactamase and armA methyltransferase. This is the first report of S. Gambia exhibiting CTX-M-3 and armA markers involved in serious infections. PMID:21270227

  8. Emissions of greenhouse gases from agriculture, land-use change, and forestry in the Gambia.

    PubMed

    Jallow, B P

    1995-01-01

    The Gambia has successfully completed a national greenhouse gas emissions inventory based on the results of a study funded by the United Nations Environment Programme (UNEP)/Global Environment Facility (GEF) Country Case Study Program. The concepts of multisectoral, multidisciplinary, and interdisciplinary collaboration were most useful in the preparation of this inventory. New data were gathered during the study period, some through regional collaboration with institutions such as Environment and Development in the Third World (ENDA-TM) Energy Program and the Ecological Monitoring Center in Dakar, Senegal, and some through national surveys and the use of remote sensing techniques, as in the Bushfires Survey. Most of the data collected are used in this paper. The Intergovernmental Panel on Climate Change/Organisation for Economic Co-operation and Development/International Energy Agency (IPCC/OECD/IEA) methodology is used to calculate greenhouse gas emissions. Many of the default data in the IPCC/OECD/IEA methodology have also been used. Overall results indicate that in the biomass sectors (agriculture, forestry, and land-use change) carbon dioxide (CO2) is emitted most, with a total of 1.7 Tg. This is followed by methane (CH4), 22.3 Gg; carbon monoxide (CO), 18.7 Gg; nitrogen oxides (NOx), 0.3 Gg; and nitrous oxide (N2O), 0.014 Gg. The Global Warming Potential (GWP) was used as an index to describe the relative effects of the various gases reported here. Based on the emissions in The Gambia in 1993, it was found that CO2 will contribute 75%, CH4 about 24.5%, and N2O 0.2% of the warming expected in the 100-year period beginning in 1993. The results in this analysis are limited by the shortcomings of the IPCC/OECD/IEA methodology and scarce national data. Because the methodology was developed outside of the developing world, most of its emissions factors and coefficients were developed and tested in environments that are very different from The Gambia. This is likely

  9. Activity of Cinnamomum osmophloeum leaf essential oil against Anopheles gambiae s.s

    PubMed Central

    2014-01-01

    Background The increasing status of insecticide resistant mosquitoes in sub-Saharan Africa is a threatening alert to the existing control efforts. All sibling species of An. gambiae complex have evolved insecticide resistance in wild populations for different approved classes of the insecticides currently in use in the field. An alternative compound for vector control is absolutely urgently needed. In this study, the larvicidal activity and chemical composition of the Cinnamomum osmophloeum leaf essential oils were investigated. Methods C. osmophloeum leaf essential oils were extracted by hydrodistillation in a Clevenger-type apparatus for 6 hours, and their chemical compositions identified using GC-MS. These oils were evaluated against An. gambiae s.s. in both laboratory and semi-field situations. The WHO test procedures for monitoring larvicidal efficacy in malaria vectors were used. Results The composition of C. osmophloeum leaf essential oil has been found to have 11 active compounds. The most abundant compound was trans-cinnamaldehyde (70.20%) and the least abundant was caryophyllene oxide (0.08%). The larvicidal activity was found to be dosage and time dependant both in laboratory and semi-field environments with mortality ranging from 0% to 100%. The LC50 value was found to vary from 22.18 to 58.15 μg/ml in the laboratory while in semi-field environments it was 11.91 to 63.63 μg/ml. The LC90 value was found to range between 57.71 to 91.54 μg/ml in the laboratory while in semi-field environments was 52.07 to 173.77 μg/ml. Mortality ranged from 13% to 100% in the laboratory while in semi-field environments it ranged between 43% to 100% within mortality recording time intervals of 12, 24, 48, and 72 hours. Conclusions The larvicidal activity shown by C. osmophloeum leaf essential oil is a promising alternative to existing larvicides or to be incorporated in integrated larval source management compounds for An. gambiae s.s control. The efficacy

  10. Development of a Gravid Trap for Collecting Live Malaria Vectors Anopheles gambiae s.l.

    PubMed Central

    Dugassa, Sisay; Lindh, Jenny M.; Oyieke, Florence; Mukabana, Wolfgang R.; Lindsay, Steven W.; Fillinger, Ulrike

    2013-01-01

    Background Effective malaria vector control targeting indoor host-seeking mosquitoes has resulted in fewer vectors entering houses in many areas of sub-Saharan Africa, with the proportion of vectors outdoors becoming more important in the transmission of this disease. This study aimed to develop a gravid trap for the outdoor collection of the malaria vector Anopheles gambiae s.l. based on evaluation and modification of commercially available gravid traps. Methods Experiments were implemented in an 80 m2 semi-field system where 200 gravid Anopheles gambiae s.s. were released nightly. The efficacy of the Box, CDC and Frommer updraft gravid traps was compared. The Box gravid trap was tested to determine if the presence of the trap over water and the trap’s sound affected catch size. Mosquitoes approaching the treatment were evaluated using electrocuting nets or detergents added to the water in the trap. Based on the results, a new gravid trap (OviART trap) that provided an open, unobstructed oviposition site was developed and evaluated. Results Box and CDC gravid traps collected similar numbers (relative rate (RR) 0.8, 95% confidence interval (CI) 0.6–1.2; p = 0.284), whereas the Frommer trap caught 70% fewer mosquitoes (RR 0.3, 95% CI 0.2–0.5; p < 0.001). The number of mosquitoes approaching the Box trap was significantly reduced when the trap was positioned over a water-filled basin compared to an open pond (RR 0.7 95% CI 0.6–0.7; p < 0.001). This effect was not due to the sound of the trap. Catch size increased by 60% (RR 1.6, 1.2–2.2; p = 0.001) with the new OviART trap. Conclusion Gravid An. Gambiae s.s. females were visually deterred by the presence of the trapping device directly over the oviposition medium. Based on these investigations, an effective gravid trap was developed that provides open landing space for egg-laying Anopheles. PMID:23861952

  11. Effect of discriminative plant-sugar feeding on the survival and fecundity of Anopheles gambiae

    PubMed Central

    Manda, Hortance; Gouagna, Louis C; Foster, Woodbridge A; Jackson, Robert R; Beier, John C; Githure, John I; Hassanali, Ahmed

    2007-01-01

    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 associated mainly with

  12. Evidence for a Lectin Specific for Sulfated Glycans in the Salivary Gland of the Malaria Vector, Anopheles gambiae

    PubMed Central

    Francischetti, Ivo M. B.; Ma, Dongying; Andersen, John F.; Ribeiro, José M. C.

    2014-01-01

    Salivary gland homogenate (SGH) from the female mosquitoes Anopheles gambiae, An. stephensi, An. freeborni, An. dirus and An. albimanus were found to exhibit hemagglutinating (lectin) activity. Lectin activity was not found for male An. gambiae, or female Ae aegypti, Culex quinquefasciatus, Phlebotomus duboscqi, and Lutzomyia longipalpis. With respect to species-specificity, An. gambiae SGH agglutinates red blood cells (RBC) from humans, horse, sheep, goat, pig, and cow; it is less active for rats RBC, and not detectable for guinea-pigs or chicken RBC. Notably, lectin activity was inhibited by low concentrations of dextran sulfate 50–500 K, fucoidan, heparin, laminin, heparin sulfate proteoglycan, sialyl-containing glycans (e.g. 3′-sialyl Lewis X, and 6′-sialyl lactose), and gangliosides (e.g. GM3, GD1, GD1b, GTB1, GM1, GQ1B), but not by simple sugars. These results imply that molecule(s) in the salivary gland target sulfated glycans. SGH from An. gambiae was also found to promote agglutination of HL-60 cells which are rich in sialyl Lewis X, a glycan that decorates PSGL-1, the neutrophils receptor that interacts with endothelial cell P-selectin. Accordingly, SGH interferes with HL-60 cells adhesion to immobilized P-selectin. Because An. gambiae SGH expresses galectins, one member of this family (herein named Agalectin) was expressed in E. coli. Recombinant Agalectin behaves as a non-covalent homodimer. It does not display lectin activity, and does not interact with 500 candidates tested in a Glycan microarray. Gel-filtration chromatography of the SGH of An. gambiae identified a fraction with hemagglutinating activity, which was analyzed by 1D PAGE followed by in-gel tryptic digestion, and nano-LC MS/MS. This approach identified several genes which emerge as candidates for a lectin targeting sulfated glycans, the first with this selectivity to be reported in the SGH of a blood-sucking arthropod. The role of salivary molecules (sialogenins) with lectin

  13. Visual arrestins in olfactory pathways of Drosophila and the malaria vector mosquito Anopheles gambiae

    PubMed Central

    Merrill, C. E.; Riesgo-Escovar, J.; Pitts, R. J.; Kafatos, F. C.; Carlson, J. R.; Zwiebel, L. J.

    2002-01-01

    Arrestins are important components for desensitization of G protein-coupled receptor cascades that mediate neurotransmission as well as olfactory and visual sensory reception. We have isolated AgArr1, an arrestin-encoding cDNA from the malaria vector mosquito, Anopheles gambiae, where olfaction is critical for vectorial capacity. Analysis of AgArr1 expression revealed an overlap between chemosensory and photoreceptor neurons. Furthermore, an examination of previously identified arrestins from Drosophila melanogaster exposed similar bimodal expression, and Drosophila arrestin mutants demonstrate impaired electrophysiological responses to olfactory stimuli. Thus, we show that arrestins in Drosophila are required for normal olfactory physiology in addition to their previously described role in visual signaling. These findings suggest that individual arrestins function in both olfactory and visual pathways in Dipteran insects; these genes may prove useful in the design of control strategies that target olfactory-dependent behaviors of insect disease vectors. PMID:11792843

  14. Regulation of carbohydrate metabolism and flight performance by a hypertrehalosaemic hormone in the mosquito Anopheles gambiae

    PubMed Central

    Kaufmann, Christian; Brown, Mark R.

    2008-01-01

    The role of adipokinetic hormones (AKHs) in the regulation of carbohydrate and lipid metabolism and flight performance was evaluated for females of the African malaria mosquito, Anopheles gambiae. Injection of various dosages of synthetic Anoga-AKH-I increased carbohydrate levels in the haemolymph and reduced glycogen reserves in sugar-fed females but did not affect lipid levels. Anoga-AKH-I enhanced the flight performance of both intact and decapitated sugar-fed females, during a 4 hour flight period. Anoga-AKH-II had no effect on carbohydrate or lipid levels or flight performance, thus its function remains unknown. Targeted RNA-interference lowered Anoga-AKH receptor expression in sugar-fed females, consequently injections of Anoga-AKH-I failed to mobilize glycogen reserves. Taken together, these results show that a primary role for the neurohormone, Anoga-AKH-I, is to elevate trehalose levels in the haemolymph of female mosquitoes. PMID:18062987

  15. A comparison of Anopheles gambiae and Plasmodium falciparum genetic structure over space and time.

    PubMed

    Prugnolle, Franck; Durand, Patrick; Jacob, Koella; Razakandrainibe, Fabien; Arnathau, Céline; Villarreal, Diana; Rousset, François; de Meeûs, Thierry; Renaud, François

    2008-03-01

    Population genetic structure and subdivision are key factors affecting the evolution of organisms. In this study, we analysed and compared the population genetic structure of the malaria parasite Plasmodium falciparum and its mosquito vector Anopheles gambiae over space and time in the Nianza Province, near Victoria Lake in Kenya. The parasites were collected from mosquitoes caught in six villages separated by up to 68 km in 2002 and 2003. A total of 545 oocysts were dissected from 122 infected mosquitoes and genotyped at seven microsatellite markers. Five hundred and forty-seven mosquitoes, both infected and uninfected, were genotyped at eight microsatellites. For the parasite and the vector, the analysis revealed no (or very little) genetic differentiation among villages. This may be explained by high local population sizes for the parasite and the mosquito. The small level of genetic differentiation observed between populations may explain the speed at which antimalarial drug resistance and insecticide resistance spread into the African continent. PMID:18321750

  16. Gambia: evaluation of the mobile health care service in West Kiang district.

    PubMed

    Foord, F

    1995-01-01

    A project to improve the quality of maternal health services was carried out over a 3-year period in West Kiang district, Gambia. Coverage of maternal care was strengthened through upgrading of personnel, TBA training, improved treatment and referral schemes, and increased numbers of visits to rural outreach areas. A control district was used to compare the impact of the interventions. During the project period of 3 years a single maternal death was registered in the intervention district, and 5 in the control area. While improved staffing and service provision led to higher degrees of coverage of maternal care services, reductions in maternal morbidity could not be documented in the intervention area. Given concern over the quality of the data possibly influencing this result, further research is necessary to determine the relationship between improved mobile maternal care services and their impact on maternal morbidity and perinatal outcome. PMID:7571704

  17. A modular chitin-binding protease associated with hemocytes and hemolymph in the mosquito Anopheles gambiae.

    PubMed

    Danielli, A; Loukeris, T G; Lagueux, M; Müller, H M; Richman, A; Kafatos, F C

    2000-06-20

    Sp22D, a modular serine protease encompassing chitin binding, low density lipoprotein receptor, and scavenger receptor cysteine-rich domains, was identified by molecular cloning in the malaria vector, Anopheles gambiae. It is expressed in multiple body parts and during much of development, most intensely in hemocytes. The protein appears to be posttranslationally modified. Its integral, putatively glycosylated form is secreted in the hemolymph, whereas a smaller form potentially generated by proteolytic processing is associated with the tissues. Bacterial challenge or wounding result in low-level RNA induction, but the protein does not bind to bacteria, nor is its processing affected by infection. However, Sp22D binds to chitin with high affinity and undergoes transient changes in processing during pupal to adult metamorphosis; it may respond to exposure to naked chitin during tissue remodeling or damage. PMID:10860981

  18. A mosquito lipoxin/lipocalin complex mediates innate immune priming in Anopheles gambiae

    PubMed Central

    Ramirez, Jose Luis; de Almeida Oliveira, Giselle; Calvo, Eric; Dalli, Jesmond; Colas, Romain A.; Serhan, Charles N.; Ribeiro, Jose M.; Barillas-Mury, Carolina

    2015-01-01

    Exposure of Anopheles gambiae mosquitoes to Plasmodium infection enhances the ability of their immune system to respond to subsequent infections. However, the molecular mechanism that allows the insect innate immune system to ‘remember' a previous encounter with a pathogen has not been established. Challenged mosquitoes constitutively release a soluble haemocyte differentiation factor into their haemolymph that, when transferred into Naive mosquitoes, also induces priming. Here we show that this factor consists of a Lipoxin/Lipocalin complex. We demonstrate that innate immune priming in mosquitoes involves a persistent increase in expression of Evokin (a lipid carrier of the lipocalin family), and in their ability to convert arachidonic acid to lipoxins, predominantly Lipoxin A4. Plasmodium ookinete midgut invasion triggers immune priming by inducing the release of a mosquito lipoxin/lipocalin complex. PMID:26100162

  19. Genome expression analysis of Anopheles gambiae: responses to injury, bacterial challenge, and malaria infection.

    PubMed

    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. PMID:12077297

  20. Genome expression analysis of Anopheles gambiae: Responses to injury, bacterial challenge, and malaria infection

    PubMed Central

    Dimopoulos, George; Christophides, George K.; Meister, Stephan; Schultz, Jörg; White, Kevin P.; Barillas-Mury, Carolina; Kafatos, Fotis C.

    2002-01-01

    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. PMID:12077297

  1. The role of reactive oxygen species on Plasmodium melanotic encapsulation in Anopheles gambiae

    PubMed Central

    Kumar, Sanjeev; Christophides, George K.; Cantera, Rafael; Charles, Bradley; Han, Yeon Soo; Meister, Stephan; Dimopoulos, George; Kafatos, Fotis C.; Barillas-Mury, Carolina

    2003-01-01

    Malaria transmission depends on the competence of some Anopheles mosquitoes to sustain Plasmodium development (susceptibility). A genetically selected refractory strain of Anopheles gambiae blocks Plasmodium development, melanizing, and encapsulating the parasite in a reaction that begins with tyrosine oxidation, and involves three quantitative trait loci. Morphological and microarray mRNA expression analysis suggest that the refractory and susceptible strains have broad physiological differences, which are related to the production and detoxification of reactive oxygen species. Physiological studies corroborate that the refractory strain is in a chronic state of oxidative stress, which is exacerbated by blood feeding, resulting in increased steady-state levels of reactive oxygen species, which favor melanization of parasites as well as Sephadex beads. PMID:14623973

  2. A mosquito lipoxin/lipocalin complex mediates innate immune priming in Anopheles gambiae.

    PubMed

    Ramirez, Jose Luis; de Almeida Oliveira, Giselle; Calvo, Eric; Dalli, Jesmond; Colas, Romain A; Serhan, Charles N; Ribeiro, Jose M; Barillas-Mury, Carolina

    2015-01-01

    Exposure of Anopheles gambiae mosquitoes to Plasmodium infection enhances the ability of their immune system to respond to subsequent infections. However, the molecular mechanism that allows the insect innate immune system to 'remember' a previous encounter with a pathogen has not been established. Challenged mosquitoes constitutively release a soluble haemocyte differentiation factor into their haemolymph that, when transferred into Naive mosquitoes, also induces priming. Here we show that this factor consists of a Lipoxin/Lipocalin complex. We demonstrate that innate immune priming in mosquitoes involves a persistent increase in expression of Evokin (a lipid carrier of the lipocalin family), and in their ability to convert arachidonic acid to lipoxins, predominantly Lipoxin A4. Plasmodium ookinete midgut invasion triggers immune priming by inducing the release of a mosquito lipoxin/lipocalin complex. PMID:26100162

  3. The role of reactive oxygen species on Plasmodium melanotic encapsulation in Anopheles gambiae.

    PubMed

    Kumar, Sanjeev; Christophides, George K; Cantera, Rafael; Charles, Bradley; Han, Yeon Soo; Meister, Stephan; Dimopoulos, George; Kafatos, Fotis C; Barillas-Mury, Carolina

    2003-11-25

    Malaria transmission depends on the competence of some Anopheles mosquitoes to sustain Plasmodium development (susceptibility). A genetically selected refractory strain of Anopheles gambiae blocks Plasmodium development, melanizing, and encapsulating the parasite in a reaction that begins with tyrosine oxidation, and involves three quantitative trait loci. Morphological and microarray mRNA expression analysis suggest that the refractory and susceptible strains have broad physiological differences, which are related to the production and detoxification of reactive oxygen species. Physiological studies corroborate that the refractory strain is in a chronic state of oxidative stress, which is exacerbated by blood feeding, resulting in increased steady-state levels of reactive oxygen species, which favor melanization of parasites as well as Sephadex beads. PMID:14623973

  4. Utilization of village health workers within a primary health care programme in The Gambia.

    PubMed

    Menon, A

    1991-08-01

    The utilization of Village Health Workers (VHWs) was studied in a rural area of The Gambia 3 years after the introduction of a village-based Primary Health Care (PHC) programme. Of 23 children who died from conditions treatable at village level, only five were first seen by the VHW. Fourteen were seen elsewhere in the region by staff more qualified than the first tier workers. The implications of this pattern of utilization on the lack of impact of VHWs on mortality are discussed. Only half of the non-fatal illnesses were attended to by VHWs. Reasons for this included such factors as lack of knowledge of services available, shortages of money, absence of the VHW at critical periods and social or political disputes with VHWs. Attempts must be made to tackle these fundamental problems if VHWs are to be successfully incorporated into the health services. PMID:1880830

  5. Characterization of two globin genes from the malaria mosquito Anopheles gambiae: divergent origin of nematoceran haemoglobins.

    PubMed

    Burmester, Thorsten; Klawitter, Sabine; Hankeln, Thomas

    2007-04-01

    The chironomid midges are the only insects that harbour true haemoglobin in their haemolymph. Here we report the identification of haemoglobin genes in two other nematoceran species. Two paralogous haemoglobin genes (glob1 and glob2) from the malaria mosquito Anopheles gambiae were cloned and sequenced. Furthermore, we identified two orthologous haemoglobin genes in the yellow fever mosquito Aedes aegypti. All four haemoglobins were predicted to be intracellular proteins, with the amino acids required for heme- and oxygen-binding being conserved. In situ-hybridization studies showed that glob1 and glob2 expression in An. gambiae is mainly associated with the tracheal system. This pattern resembles that of other insect intracellular globins. We also observed expression of glob2 in visceral muscles. Phylogenetic analyses showed that the globins of the mosquitoes and the Chironomidae are not orthologous. The chironomid haemoglobins share a recent common origin with the brachyceran glob1 proteins. The mosquito glob1 and glob2 proteins, which separated by gene duplication around 170 million years ago, form a distinct clade of more ancient evolutionary origin within the insects. The glob1 genes have introns in the ancestral globin positions B12.2 and G7.0. An additional intron was observed in Ae. aegypti glob1 helix position E18.0, providing evidence for a recent intron gain event. Both mosquito glob2 genes have lost the B12.2 intron. This pattern must be interpreted in terms of dynamic intron gain and loss events in the globin gene lineage. PMID:17298561

  6. Immunogenic and antioxidant effects of a pathogen-associated prenyl pyrophosphate in Anopheles gambiae.

    PubMed

    Lindberg, Bo G; Merritt, Eleanor A; Rayl, Melanie; Liu, Chenxiao; Parmryd, Ingela; Olofsson, Berit; Faye, Ingrid

    2013-01-01

    Despite efficient vector transmission, Plasmodium parasites suffer great bottlenecks during their developmental stages within Anopheles mosquitoes. The outcome depends on a complex three-way interaction between host, parasite and gut bacteria. Although considerable progress has been made recently in deciphering Anopheles effector responses, little is currently known regarding the underlying microbial immune elicitors. An interesting candidate in this sense is the pathogen-derived prenyl pyrophosphate and designated phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), found in Plasmodium and most eubacteria but not in higher eukaryotes. HMBPP is the most potent stimulant known of human Vγ9Vδ2 T cells, a unique lymphocyte subset that expands during several infections including malaria. In this study, we show that Vγ9Vδ2 T cells proliferate when stimulated with supernatants from intraerythrocytic stages of Plasmodium falciparum cultures, suggesting that biologically relevant doses of phosphoantigens are excreted by the parasite. Next, we used Anopheles gambiae to investigate the immune- and redox- stimulating effects of HMBPP. We demonstrate a potent activation in vitro of all but one of the signaling pathways earlier implicated in the human Vγ9Vδ2 T cell response, as p38, JNK and PI3K/Akt but not ERK were activated in the A. gambiae 4a3B cell line. Additionally, both HMBPP and the downstream endogenous metabolite isopentenyl pyrophosphate displayed antioxidant effects by promoting cellular tolerance to hydrogen peroxide challenge. When provided in the mosquito blood meal, HMBPP induced temporal changes in the expression of several immune genes. In contrast to meso-diaminopimelic acid containing peptidoglycan, HMBPP induced expression of dual oxidase and nitric oxide synthase, two key determinants of Plasmodium infection. Furthermore, temporal fluctuations in midgut bacterial numbers were observed. The multifaceted effects observed in this

  7. Antimicrobial Susceptibility and Resistance Patterns among Helicobacter pylori Strains from The Gambia, West Africa

    PubMed Central

    Berg, Douglas E.; Antonio, Martin; Corrah, Tumani; Tapgun, Mary; Walton, Robert; Thomas, Vivat; Galano, Juan J.; Sancho, Javier; Adegbola, Richard A.; Thomas, Julian E.

    2013-01-01

    Helicobacter pylori is a globally important and genetically diverse gastric pathogen that infects most people in developing countries. Eradication efforts are complicated by antibiotic resistance, which varies in frequency geographically. There are very few data on resistance in African strains. Sixty-four Gambian H. pylori strains were tested for antibiotic susceptibility. The role of rdxA in metronidazole (Mtz) susceptibility was tested by DNA transformation and sequencing; RdxA protein variants were interpreted in terms of RdxA structure. Forty-four strains (69%) were resistant to at least 8 μg of Mtz/ml. All six strains from infants, but only 24% of strains from adults, were sensitive (P = 0.0031). Representative Mtz-resistant (Mtzr) strains were rendered Mtz susceptible (Mtzs) by transformation with a functional rdxA gene; conversely, Mtzs strains were rendered Mtzr by rdxA inactivation. Many mutations were found by Gambian H. pylori rdxA sequencing; mutations that probably inactivated rdxA in Mtzr strains were identified and explained using RdxA protein's structure. All of the strains were sensitive to clarithromycin and erythromycin. Amoxicillin and tetracycline resistance was rare. Sequence analysis indicated that most tetracycline resistance, when found, was not due to 16S rRNA gene mutations. These data suggest caution in the use of Mtz-based therapies in The Gambia. The increasing use of macrolides against respiratory infections in The Gambia calls for continued antibiotic susceptibility monitoring. The rich variety of rdxA mutations that we found will be useful in further structure-function studies of RdxA, the enzyme responsible for Mtz susceptibility in this important pathogen. PMID:23263004

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

    PubMed

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

    2006-06-01

    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. 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 of invading

  9. Cytochrome P450 associated with insecticide resistance catalyzes cuticular hydrocarbon production in Anopheles gambiae

    PubMed Central

    Balabanidou, Vasileia; Kampouraki, Anastasia; MacLean, Marina; Blomquist, Gary J.; Tittiger, Claus; Juárez, M. Patricia; Mijailovsky, Sergio J.; Chalepakis, George; Anthousi, Amalia; Lynd, Amy; Antoine, Sanou; Hemingway, Janet; Ranson, Hilary; Lycett, Gareth J.; Vontas, John

    2016-01-01

    The role of cuticle changes in insecticide resistance in the major malaria vector Anopheles gambiae was assessed. The rate of internalization of 14C deltamethrin was significantly slower in a resistant strain than in a susceptible strain. Topical application of an acetone insecticide formulation to circumvent lipid-based uptake barriers decreased the resistance ratio by ∼50%. Cuticle analysis by electron microscopy and characterization of lipid extracts indicated that resistant mosquitoes had a thicker epicuticular layer and a significant increase in cuticular hydrocarbon (CHC) content (∼29%). However, the CHC profile and relative distribution were similar in resistant and susceptible insects. The cellular localization and in vitro activity of two P450 enzymes, CYP4G16 and CYP4G17, whose genes are frequently overexpressed in resistant Anopheles mosquitoes, were analyzed. These enzymes are potential orthologs of the CYP4G1/2 enzymes that catalyze the final step of CHC biosynthesis in Drosophila and Musca domestica, respectively. Immunostaining indicated that both CYP4G16 and CYP4G17 are highly abundant in oenocytes, the insect cell type thought to secrete hydrocarbons. However, an intriguing difference was indicated; CYP4G17 occurs throughout the cell, as expected for a microsomal P450, but CYP4G16 localizes to the periphery of the cell and lies on the cytoplasmic side of the cell membrane, a unique position for a P450 enzyme. CYP4G16 and CYP4G17 were functionally expressed in insect cells. CYP4G16 produced hydrocarbons from a C18 aldehyde substrate and thus has bona fide decarbonylase activity similar to that of dmCYP4G1/2. The data support the hypothesis that the coevolution of multiple mechanisms, including cuticular barriers, has occurred in highly pyrethroid-resistant An. gambiae. PMID:27439866

  10. Visualizing Non Infectious and Infectious Anopheles gambiae Blood Feedings in Naive and Saliva-Immunized Mice

    PubMed Central

    Choumet, Valerie; Attout, Tarik; Chartier, Loïc; Khun, Huot; Sautereau, Jean; Robbe-Vincent, Annie; Brey, Paul; Huerre, Michel; Bain, Odile

    2012-01-01

    Background Anopheles gambiae is a major vector of malaria and lymphatic filariasis. The arthropod-host interactions occurring at the skin interface are complex and dynamic. We used a global approach to describe the interaction between the mosquito (infected or uninfected) and the skin of mammals during blood feeding. Methods Intravital video microscopy was used to characterize several features during blood feeding. The deposition and movement of Plasmodium berghei sporozoites in the dermis were also observed. We also used histological techniques to analyze the impact of infected and uninfected feedings on the skin cell response in naive mice. Results The mouthparts were highly mobile within the skin during the probing phase. Probing time increased with mosquito age, with possible effects on pathogen transmission. Repletion was achieved by capillary feeding. The presence of sporozoites in the salivary glands modified the behavior of the mosquitoes, with infected females tending to probe more than uninfected females (86% versus 44%). A white area around the tip of the proboscis was observed when the mosquitoes fed on blood from the vessels of mice immunized with saliva. Mosquito feedings elicited an acute inflammatory response in naive mice that peaked three hours after the bite. Polynuclear and mast cells were associated with saliva deposits. We describe the first visualization of saliva in the skin by immunohistochemistry (IHC) with antibodies directed against saliva. Both saliva deposits and sporozoites were detected in the skin for up to 18 h after the bite. Conclusion This study, in which we visualized the probing and engorgement phases of Anopheles gambiae blood meals, provides precise information about the behavior of the insect as a function of its infection status and the presence or absence of anti-saliva antibodies. It also provides insight into the possible consequences of the inflammatory reaction for blood feeding and pathogen transmission. PMID

  11. Treatment uptake by individuals infected with Plasmodium falciparum in rural Gambia, West Africa.

    PubMed Central

    von Seidlein, Lorenz; Clarke, Sian; Alexander, Neâl; Manneh, Fandingding; Doherty, Tom; Pinder, Margaret; Walraven, Gijs; Greenwood, Brian

    2002-01-01

    OBJECTIVE: To find out what proportion of Plasmodium falciparum infections are treated in rural Gambia. METHODS: Subjects from four villages in the Gambia were followed over nine months through visits to village health workers. Monthly cross-sectional malaria surveys measured the prevalence of P. falciparum infection. Linked databases were searched for treatment requests. Treated cases were individuals with parasitaemia who requested treatment during narrow or extended periods (14 or 28 days, respectively) before or after a positive blood film was obtained. FINDINGS: Parasite prevalence peaked in November 1998, when 399/653 (61%) individuals had parasitaemia. Parasite prevalence was highest throughout the study in children aged 5-10 years. Although access to treatment was better than in most of sub-Saharan Africa, only 20% of infected individuals sought medical treatment up to 14 days before or after a positive blood film. Within two months of a positive blood film, 199/726 (27%) individuals with parasitaemia requested treatment. Despite easy access to health care, less than half (42%) of those with parasite densities consistent with malaria attacks (5000/ l) requested treatment. High parasite density and infection during October-November were associated with more frequent treatment requests. Self-treatment was infrequent in study villages: in 3/120 (2.5%) households antimalarial drugs had been used in the preceding malaria season. CONCLUSION: Many P. falciparum infections may be untreated because of their subclinical nature. Intermittent presumptive treatment may reduce morbidity and mortality. It is likely that not all untreated infections were asymptomatic. Qualitative research should explore barriers to treatment uptake, to allow educational interventions to be planned. PMID:12471399

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

    PubMed Central

    Ng'habi, Kija R; John, Bernadette; Nkwengulila, Gamba; Knols, Bart GJ; Killeen, Gerry F; Ferguson, Heather 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 environmental conditions that increase their mating competitiveness, and incorporate them into laboratory rearing regimes. Methods Anopheles gambiae larvae were allocated to three crowding treatments with the same food input per larva. Emerged males were competed against one another for access to females, and their corresponding longevity and energetic reserves measured. Results Males from the low-crowding treatment were much more likely to acquire the first mating. They won the first female approximately 11 times more often than those from the high-crowding treatment (Odds ratio = 11.17) and four times more often than those from the medium-crowding treatment (Odds ratio = 3.51). However, there was no overall difference in the total number of matings acquired by males from different treatments (p = 0.08). The survival of males from the low crowding treatment was lower than those from other treatments. The body size and teneral reserves of adult males did not differ between crowding treatments, but larger males were more likely to acquire mates than small individuals. Conclusion Larval crowding and body size have strong, independent effects on the mating competitiveness of adult male An. gambiae. Thus manipulation of larval crowding during mass rearing could provide a simple technique for boosting the competitiveness of sterile or transgenic male mosquitoes prior to release. PMID:16197541

  13. Anopheles gambiae Immune Responses to Human and Rodent Plasmodium Parasite Species

    PubMed Central

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

    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. 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 of invading

  14. Immunogenic and Antioxidant Effects of a Pathogen-Associated Prenyl Pyrophosphate in Anopheles gambiae

    PubMed Central

    Lindberg, Bo G.; Merritt, Eleanor A.; Rayl, Melanie; Liu, Chenxiao; Parmryd, Ingela; Olofsson, Berit; Faye, Ingrid

    2013-01-01

    Despite efficient vector transmission, Plasmodium parasites suffer great bottlenecks during their developmental stages within Anopheles mosquitoes. The outcome depends on a complex three-way interaction between host, parasite and gut bacteria. Although considerable progress has been made recently in deciphering Anopheles effector responses, little is currently known regarding the underlying microbial immune elicitors. An interesting candidate in this sense is the pathogen-derived prenyl pyrophosphate and designated phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), found in Plasmodium and most eubacteria but not in higher eukaryotes. HMBPP is the most potent stimulant known of human Vγ9Vδ2 T cells, a unique lymphocyte subset that expands during several infections including malaria. In this study, we show that Vγ9Vδ2 T cells proliferate when stimulated with supernatants from intraerythrocytic stages of Plasmodium falciparum cultures, suggesting that biologically relevant doses of phosphoantigens are excreted by the parasite. Next, we used Anopheles gambiae to investigate the immune- and redox- stimulating effects of HMBPP. We demonstrate a potent activation in vitro of all but one of the signaling pathways earlier implicated in the human Vγ9Vδ2 T cell response, as p38, JNK and PI3K/Akt but not ERK were activated in the A. gambiae 4a3B cell line. Additionally, both HMBPP and the downstream endogenous metabolite isopentenyl pyrophosphate displayed antioxidant effects by promoting cellular tolerance to hydrogen peroxide challenge. When provided in the mosquito blood meal, HMBPP induced temporal changes in the expression of several immune genes. In contrast to meso-diaminopimelic acid containing peptidoglycan, HMBPP induced expression of dual oxidase and nitric oxide synthase, two key determinants of Plasmodium infection. Furthermore, temporal fluctuations in midgut bacterial numbers were observed. The multifaceted effects observed in this

  15. Seasonal variation in metabolic rate, flight activity and body size of Anopheles gambiae in the Sahel

    PubMed Central

    Huestis, Diana L.; Yaro, Alpha S.; Traoré, Adama I.; Dieter, Kathryne L.; Nwagbara, Juliette I.; Bowie, Aleah C.; Adamou, Abdoulaye; Kassogué, Yaya; Diallo, Moussa; Timbiné, Seydou; Dao, Adama; Lehmann, Tovi

    2012-01-01

    SUMMARY Malaria in Africa is vectored primarily by the Anopheles gambiae complex. Although the mechanisms of population persistence during the dry season are not yet known, targeting dry season mosquitoes could provide opportunities for vector control. In the Sahel, it appears likely that M-form A. gambiae survive by aestivation (entering a dormant state). To assess the role of eco-physiological changes associated with dry season survival, we measured body size, flight activity and metabolic rate of wild-caught mosquitoes throughout 1 year in a Sahelian locality, far from permanent water sources, and at a riparian location adjacent to the Niger River. We found significant seasonal variation in body size at both the Sahelian and riparian sites, although the magnitude of the variation was greater in the Sahel. For flight activity, significant seasonality was only observed in the Sahel, with increased flight activity in the wet season when compared with that just prior to and throughout the dry season. Whole-organism metabolic rate was affected by numerous biotic and abiotic factors, and a significant seasonal component was found at both locations. However, assay temperature accounted completely for seasonality at the riparian location, while significant seasonal variation remained after accounting for all measured variables in the Sahel. Interestingly, we did not find that mean metabolic rate was lowest during the dry season at either location, contrary to our expectation that mosquitoes would conserve energy and increase longevity by reducing metabolism during this time. These results indicate that mosquitoes may use mechanisms besides reduced metabolic rate to enable survival during the Sahelian dry season. PMID:22623189

  16. Cytochrome P450 associated with insecticide resistance catalyzes cuticular hydrocarbon production in Anopheles gambiae.

    PubMed

    Balabanidou, Vasileia; Kampouraki, Anastasia; MacLean, Marina; Blomquist, Gary J; Tittiger, Claus; Juárez, M Patricia; Mijailovsky, Sergio J; Chalepakis, George; Anthousi, Amalia; Lynd, Amy; Antoine, Sanou; Hemingway, Janet; Ranson, Hilary; Lycett, Gareth J; Vontas, John

    2016-08-16

    The role of cuticle changes in insecticide resistance in the major malaria vector Anopheles gambiae was assessed. The rate of internalization of (14)C deltamethrin was significantly slower in a resistant strain than in a susceptible strain. Topical application of an acetone insecticide formulation to circumvent lipid-based uptake barriers decreased the resistance ratio by ∼50%. Cuticle analysis by electron microscopy and characterization of lipid extracts indicated that resistant mosquitoes had a thicker epicuticular layer and a significant increase in cuticular hydrocarbon (CHC) content (∼29%). However, the CHC profile and relative distribution were similar in resistant and susceptible insects. The cellular localization and in vitro activity of two P450 enzymes, CYP4G16 and CYP4G17, whose genes are frequently overexpressed in resistant Anopheles mosquitoes, were analyzed. These enzymes are potential orthologs of the CYP4G1/2 enzymes that catalyze the final step of CHC biosynthesis in Drosophila and Musca domestica, respectively. Immunostaining indicated that both CYP4G16 and CYP4G17 are highly abundant in oenocytes, the insect cell type thought to secrete hydrocarbons. However, an intriguing difference was indicated; CYP4G17 occurs throughout the cell, as expected for a microsomal P450, but CYP4G16 localizes to the periphery of the cell and lies on the cytoplasmic side of the cell membrane, a unique position for a P450 enzyme. CYP4G16 and CYP4G17 were functionally expressed in insect cells. CYP4G16 produced hydrocarbons from a C18 aldehyde substrate and thus has bona fide decarbonylase activity similar to that of dmCYP4G1/2. The data support the hypothesis that the coevolution of multiple mechanisms, including cuticular barriers, has occurred in highly pyrethroid-resistant An gambiae. PMID:27439866

  17. Inferring selection in the Anopheles gambiae species complex: an example from immune-related serine protease inhibitors

    PubMed Central

    Obbard, Darren J; Welch, John J; Little, Tom J

    2009-01-01

    Background Mosquitoes of the Anopheles gambiae species complex are the primary vectors of human malaria in sub-Saharan Africa. Many host genes have been shown to affect Plasmodium development in the mosquito, and so are expected to engage in an evolutionary arms race with the pathogen. However, there is little conclusive evidence that any of these mosquito genes evolve rapidly, or show other signatures of adaptive evolution. Methods Three serine protease inhibitors have previously been identified as candidate immune system genes mediating mosquito-Plasmodium interaction, and serine protease inhibitors have been identified as hot-spots of adaptive evolution in other taxa. Population-genetic tests for selection, including a recent multi-gene extension of the McDonald-Kreitman test, were applied to 16 serine protease inhibitors and 16 other genes sampled from the An. gambiae species complex in both East and West Africa. Results Serine protease inhibitors were found to show a marginally significant trend towards higher levels of amino acid diversity than other genes, and display extensive genetic structuring associated with the 2La chromosomal inversion. However, although serpins are candidate targets for strong parasite-mediated selection, no evidence was found for rapid adaptive evolution in these genes. Conclusion It is well known that phylogenetic and population history in the An. gambiae complex can present special problems for the application of standard population-genetic tests for selection, and this may explain the failure of this study to detect selection acting on serine protease inhibitors. The pitfalls of uncritically applying these tests in this species complex are highlighted, and the future prospects for detecting selection acting on the An. gambiae genome are discussed. PMID:19497100

  18. Comparative transcriptome analyses of deltamethrin-resistant and -susceptible Anopheles gambiae mosquitoes from Kenya by RNA-Seq.

    PubMed

    Bonizzoni, Mariangela; Afrane, Yaw; Dunn, William Augustine; Atieli, Francis K; Zhou, Goufa; Zhong, Daibin; Li, Jun; Githeko, Andrew; Yan, Guiyun

    2012-01-01

    Malaria causes more than 300 million clinical cases and 665,000 deaths each year, and the majority of the mortality and morbidity occurs in sub-Saharan Africa. Due to the lack of effective vaccines and wide-spread resistance to antimalarial drugs, mosquito control is the primary method of malaria prevention and control. Currently, malaria vector control relies on the use of insecticides, primarily pyrethroids. The extensive use of insecticides has imposed strong selection pressures for resistance in the mosquito populations. Consequently, resistance to pyrethroids in Anopheles gambiae, the main malaria vector in sub-Saharan Africa, has become a major obstacle for malaria control. A key element of resistance management is the identification of resistance mechanisms and subsequent development of reliable resistance monitoring tools. Field-derived An. gambiae from Western Kenya were phenotyped as deltamethrin-resistant or -susceptible by the standard WHO tube test, and their expression profile compared by RNA-seq. Based on the current annotation of the An. gambiae genome, a total of 1,093 transcripts were detected as significantly differentially accumulated between deltamethrin-resistant and -susceptible mosquitoes. These transcripts are distributed over the entire genome, with a large number mapping in QTLs previously linked to pyrethorid resistance, and correspond to heat-shock proteins, metabolic and transport functions, signal transduction activities, cytoskeleton and others. The detected differences in transcript accumulation levels between resistant and susceptible mosquitoes reflect transcripts directly or indirectly correlated with pyrethroid resistance. RNA-seq data also were used to perform a de-novo Cufflinks assembly of the An. gambiae genome. PMID:22970263

  19. Comparative Transcriptome Analyses of Deltamethrin-Resistant and -Susceptible Anopheles gambiae Mosquitoes from Kenya by RNA-Seq

    PubMed Central

    Bonizzoni, Mariangela; Afrane, Yaw; Dunn, William Augustine; Atieli, Francis K.; Zhou, Goufa; Zhong, Daibin; Li, Jun; Githeko, Andrew; Yan, Guiyun

    2012-01-01

    Malaria causes more than 300 million clinical cases and 665,000 deaths each year, and the majority of the mortality and morbidity occurs in sub-Saharan Africa. Due to the lack of effective vaccines and wide-spread resistance to antimalarial drugs, mosquito control is the primary method of malaria prevention and control. Currently, malaria vector control relies on the use of insecticides, primarily pyrethroids. The extensive use of insecticides has imposed strong selection pressures for resistance in the mosquito populations. Consequently, resistance to pyrethroids in Anopheles gambiae, the main malaria vector in sub-Saharan Africa, has become a major obstacle for malaria control. A key element of resistance management is the identification of resistance mechanisms and subsequent development of reliable resistance monitoring tools. Field-derived An. gambiae from Western Kenya were phenotyped as deltamethrin-resistant or -susceptible by the standard WHO tube test, and their expression profile compared by RNA-seq. Based on the current annotation of the An. gambiae genome, a total of 1,093 transcripts were detected as significantly differentially accumulated between deltamethrin-resistant and -susceptible mosquitoes. These transcripts are distributed over the entire genome, with a large number mapping in QTLs previously linked to pyrethorid resistance, and correspond to heat-shock proteins, metabolic and transport functions, signal transduction activities, cytoskeleton and others. The detected differences in transcript accumulation levels between resistant and susceptible mosquitoes reflect transcripts directly or indirectly correlated with pyrethroid resistance. RNA-seq data also were used to perform a de-novo Cufflinks assembly of the An. gambiae genome. PMID:22970263

  20. Comparison of the oxidative phosphorylation (OXPHOS) nuclear genes in the genomes of Drosophila melanogaster, Drosophila pseudoobscura and Anopheles gambiae

    PubMed Central

    Tripoli, Gaetano; D'Elia, Domenica; Barsanti, Paolo; Caggese, Corrado

    2005-01-01

    Background In eukaryotic cells, oxidative phosphorylation (OXPHOS) uses the products of both nuclear and mitochondrial genes to generate cellular ATP. Interspecies comparative analysis of these genes, which appear to be under strong functional constraints, may shed light on the evolutionary mechanisms that act on a set of genes correlated by function and subcellular localization of their products. Results We have identified and annotated the Drosophila melanogaster, D. pseudoobscura and Anopheles gambiae orthologs of 78 nuclear genes encoding mitochondrial proteins involved in oxidative phosphorylation by a comparative analysis of their genomic sequences and organization. We have also identified 47 genes in these three dipteran species each of which shares significant sequence homology with one of the above-mentioned OXPHOS orthologs, and which are likely to have originated by duplication during evolution. Gene structure and intron length are essentially conserved in the three species, although gain or loss of introns is common in A. gambiae. In most tissues of D. melanogaster and A. gambiae the expression level of the duplicate gene is much lower than that of the original gene, and in D. melanogaster at least, its expression is almost always strongly testis-biased, in contrast to the soma-biased expression of the parent gene. Conclusions Quickly achieving an expression pattern different from the parent genes may be required for new OXPHOS gene duplicates to be maintained in the genome. This may be a general evolutionary mechanism for originating phenotypic changes that could lead to species differentiation. PMID:15693940

  1. Olfactory basis of floral preference of the malaria vector Anopheles gambiae (Diptera: Culicidae) among common African plants.

    PubMed

    Nikbakhtzadeh, Mahmood R; Terbot, John W; Otienoburu, Philip E; Foster, Woodbridge A

    2014-12-01

    Mosquitoes of both sexes feed on plants to obtain sugar. Nocturnal species probably locate the plants primarily by their volatile semiochemicals that also form the basis for the mosquitoes' innate plant-species preferences. To evaluate these olfactory preferences quantitatively, we used a two-choice wind-tunnel olfactometer to measure the upwind orientation of Anopheles gambiae Giles, an important vector of malaria in equatorial Africa, toward odor plumes produced by nine plant species common where this mosquito occurs. These plants are reported to induce feeding behaviors in An. gambiae and to produce floral or extrafloral nectar. Results presented here demonstrated that the volatiles of S. didymobotrya, P. hysterophorus, S. occidentalis, and L. camara, in descending order of numbers of mosquitoes responding, were all attractive, compared to a control plant species, whereas D. stramonium, R. communis, S. bicapsularis, T. stans, and T. diversifolia were not. As expected, chromatographic analysis of the headspace of attractive plants whose volatiles were captured by stir-bar sorptive extraction revealed a wide range of compounds, primarily terpenoids. Once their bioactivity and attractiveness for An. gambiae, alone and in blends, has been firmly established, some of these semiochemicals may have applications in population sampling and control. PMID:25424267

  2. Repellent, Irritant and Toxic Effects of 20 Plant Extracts on Adults of the Malaria Vector Anopheles gambiae Mosquito

    PubMed Central

    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. PMID:24376515

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

    PubMed

    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. PMID:24376515

  4. Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates

    PubMed Central

    Okanda, FM; Dao, A; Njiru, BN; Arija, J; Akelo, HA; Touré, Y; Odulaja, A; Beier, JC; Githure, JI; Yan, G; Gouagna, LC; Knols, BGJ; Killeen, GF

    2002-01-01

    Background Plasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release. Methods Varying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females. Results Male An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches. Conclusions Sexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future. PMID:12296972

  5. Barriers to Emergency Obstetric Care Services in Perinatal Deaths in Rural Gambia: A Qualitative In-Depth Interview Study

    PubMed Central

    Jammeh, Abdou; Sundby, Johanne; Vangen, Siri

    2011-01-01

    Objective. The Gambia has one of the world's highest perinatal mortality rates. We explored barriers of timely access to emergency obstetric care services resulting in perinatal deaths and in survivors of severe obstetric complications in rural Gambia. Method. We applied the “three delays” model as a framework for assessing contributing factors to perinatal deaths and obstetric complications. Qualitative in-depth interviews were conducted with 20 survivors of severe obstetric complications at home settings within three to four weeks after hospital discharge. Family members and traditional birth attendants were also interviewed. The interviews were translated into English and transcribed verbatim. We used content analysis to identify barriers of care. Results. Transport/cost-related delays are the major contributors of perinatal deaths in this study. A delay in recognising danger signs of pregnancy/labour or decision to seek care outside the home was the second important contributor of perinatal deaths. Decision to seek care may be timely, but impaired access precluded utilization of EmOC services. Obtaining blood for transfusion was also identified as a deterrent to appropriate care. Conclusion. Delays in accessing EmOC are critical in perinatal deaths. Thus, timely availability of emergency transport services and prompt decision-making are warranted for improved perinatal outcomes in rural Gambia. PMID:21766039

  6. Identification of morphological and chemical markers of dry- and wet-season conditions in female Anopheles gambiae mosquitoes

    PubMed Central

    2014-01-01

    Background Increased understanding of the dry-season survival mechanisms of Anopheles gambiae in semi-arid regions could benefit vector control efforts by identifying weak links in the transmission cycle of malaria. In this study, we examined the effect of photoperiod and relative humidity on morphologic and chemical traits known to control water loss in mosquitoes. Methods Anopheles gambiae body size (indexed by wing length), mesothoracic spiracle size, and cuticular hydrocarbon composition (both standardized by body size) were examined in mosquitoes raised from eggs exposed to short photoperiod and low relative humidity, simulating the dry season, or long photoperiod and high relative humidity, simulating the wet-season. Results Mosquitoes exposed to short photoperiod exhibited larger body size and larger mesothoracic spiracle length than mosquitoes exposed to long photoperiod. Mosquitoes exposed to short photoperiod and low relative humidity exhibited greater total cuticular hydrocarbon amount than mosquitoes exposed to long photoperiod and high relative humidity. In addition, total cuticular hydrocarbon amount increased with age and was higher in mated females. Mean n-alkane retention time (a measure of cuticular hydrocarbon chain length) was lower in mosquitoes exposed to short photoperiod and low relative humidity, and increased with age. Individual cuticular hydrocarbon peaks were examined, and several cuticular hydrocarbons were identified as potential biomarkers of dry- and wet-season conditions, age, and insemination status. Conclusions Results from this study indicate that morphological and chemical changes underlie aestivation of Anopheles gambiae and may serve as biomarkers of aestivation. PMID:24970701

  7. Limited usefulness of microsatellite markers from the malaria vector Anopheles gambiae when applied to the closely related species Anopheles melas.

    PubMed

    Deitz, Kevin C; Reddy, Vamsi P; Reddy, Michael R; Satyanarayanah, Neha; Lindsey, Michael W; Overgaard, Hans J; Jawara, Musa; Caccone, Adalgisa; Slotman, Michel A

    2012-07-01

    Anopheles melas is a brackish water mosquito found in coastal West Africa where it is a dominant malaria vector locally. In order to facilitate genetic studies of this species, 45 microsatellite loci originally developed for Anopheles gambiae were sequenced in An. melas. Those that were suitable based on repeat number and flanking regions were examined in 2 natural populations from Equatorial Guinea. Only 15 loci were eventually deemed suitable as polymorphic markers in An. melas populations. These loci were screened in 4 populations from a wider geographic range. Heterozygosity estimates ranged from 0.18 to 0.79, and 2.5-15 average alleles were observed per locus, yielding 13 highly polymorphic markers and 2 loci with lower variability. To examine the usefulness of microsatellite markers when applied in a sibling species, the original An. gambiae specific markers were used to amplify 5 loci in An. melas. Null alleles were found for 1 An. gambiae marker. We discuss the pitfalls of using microsatellite loci across closely related species and conclude that in addition to the problem of null alleles associated with this practice, many loci may prove to be of very limited use as polymorphic markers even when used in a sibling species. PMID:22593601

  8. Constituents of the Essential Oil of Suregada zanzibariensis Leaves are Repellent to the Mosquito, Anopheles gambiae s.s.

    PubMed Central

    Innocent, Ester; Joseph, Cosam C.; Gikonyo, Nicholas K.; Nkunya, Mayunga H.H.; Hassanali, Ahmed

    2010-01-01

    In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents. PMID:20569134

  9. Congruence and indifference between two molecular markers for understanding oral evolution in the Marynidae sensu lato (Ciliophora, Colpodea)

    PubMed Central

    Dunthorn, Micah; Katz, Laura A.; Stoeck, Thorsten; Foissner, Wilhelm

    2012-01-01

    Our understanding of the evolution of oral structures within the Colpodida is confounded by the low number of morphological characters that can be used in constructing hypotheses, and by the low taxon and character sampling in molecular phylogenetic analyses designed to assess these hypotheses. Here we increase character sampling by sequencing the mitochondrial SSU-rDNA locus for three isolates of the Marynidae sensu lato. We show that the inferred mitochondrial and nuclear SSU-rDNA trees, as well as concatenated and constrained analyses, are congruent in not recovering a monophyletic Marynidae. However, due to low node support, the trees are indifferent to whether the morphological characters used to unite the Marynidae are the result of retention of ancestral states or convergence. In light of this indifference and an increased amount of nuclear and mitochondrial SSU-rDNA data, alternative hypotheses of oral evolution in the Colpodida are presented. PMID:22356924

  10. Optimization of the Esperanza window trap for the collection of the African onchocerciasis vector Simulium damnosum sensu lato.

    PubMed

    Toé, Laurent D; Koala, Lassane; Burkett-Cadena, Nathan D; Traoré, Bizini M; Sanfo, Moussa; Kambiré, Sié Roger; Cupp, Eddie W; Traoré, Soungalo; Yameogo, Laurent; Boakye, Daniel; Rodríguez-Pérez, Mario A; Unnasch, Thomas R

    2014-09-01

    A simple inexpensive trap (Esperanza window trap) was shown recently to collect significant numbers of Simulium ochraceum sensu lato, a major vector of Onchocerca volvulus in Mesoamerica. Here, we report studies optimizing this trap for the collection of Simulium damnosum s.l., the major vector of O. volvulus in Africa. A shortened, blue and black striped version of the Esperanza window trap, when baited with a combination of CO2 and worn trousers, rivalled human landing collections in the number of S. damnosum s.l. females collected. Traps baited with a commercially available human skin lure and CO2 resulted in collections that were not significantly different than those obtained from traps baited with worn trousers and CO2. This suggests that the Esperanza window trap may offer a replacement for human landing collections for monitoring onchocerciasis transmission in Africa. PMID:24794201

  11. Genetic Diversity of Phytophthora infestans sensu lato in Ecuador Provides New Insight Into the Origin of This Important Plant Pathogen.

    PubMed

    Adler, N E; Erselius, L J; Chacón, M G; Flier, W G; Ordoñez, M E; Kroon, L P N M; Forbes, G A

    2004-02-01

    ABSTRACT The metapopulation structure of Phytophthora infestans sensu lato is genetically diverse in the highlands of Ecuador. Previous reports documented the diversity associated with four putative clonal lineages of the pathogen collected from various hosts in the genus Solanum. This paper simultaneously analyzes diversity of the complete collection of isolates, including a large number that had not yet been reported. This analysis confirmed the existence of three pathogen populations, which all appear to be clonal lineages, and that correspond to those previously reported as US-1, EC-1, and EC-3. No evidence was found from the analyses of recently collected isolates that would contradict earlier reports about these three lineages. In contrast, new data from a group of isolates from several similar hosts caused us to modify the previous description of clonal lineage EC-2 and its previously proposed hosts, S. brevifolium and S. tetrapetalum. Given the uncertainty associated with the identification of these hosts, which all belong to the section Anarrhichomenum, we refer to them as the Anarrhichomenum complex, pending further taxonomic clarification. New pathogen genotypes associated with the Anarrhichomenum complex were isolated recently that are A1 mating type and Ia mitochondrial DNA (mtDNA) haplotype, and therefore differ from the previously described EC-2 lineage, which is A2 and Ic, respectively. Because of uncertainty on host identification, we do not know if the new genotypes are limited to one host species and therefore represent yet another host-adapted clonal lineage. For now, we refer to the new genotypes and previously described EC-2 genotypes, together, as the pathogen group attacking the Anarrhichomenum complex. Two A2 isolates identical to the previously described EC-2 archetype were collected from severely infected plants of pear melon (S. muricatum). Pear melon is generally attacked by US-1, and this is the first clear case we have documented in

  12. Correlation of Borrelia burgdorferi sensu lato prevalence in questing Ixodes ricinus ticks with specific abiotic traits in the western palearctic.

    PubMed

    Estrada-Peña, Agustín; Ortega, Carmelo; Sánchez, Nely; Desimone, Lorenzo; Sudre, Bertrand; Suk, Jonathan E; Semenza, Jan C

    2011-06-01

    This meta-analysis of reports examining ticks throughout the Western Palearctic region indicates a distinct geographic pattern for Borrelia burgdorferi sensu lato prevalence in questing nymphal Ixodes ricinus ticks. The greatest prevalence was reported between the 5°E and 25°E longitudes based on an analysis of 123 collection points with 37,940 nymphal tick specimens (87.43% of total nymphs; 56.35% of total ticks in the set of reports over the target area). Climatic traits, such as temperature and vegetation stress, and their seasonality correlated with Borrelia prevalence in questing ticks. The greatest prevalence was associated with mild winter, high summer, and low seasonal amplitude of temperatures within the range of the tick vector, higher vegetation indices in the May-June period, and well-connected vegetation patches below a threshold at which rates suddenly drop. Classification of the target territory using a qualitative risk index derived from the abiotic variables produced an indicator of the probability of finding infected ticks in the Western Palearctic region. No specific temporal trends were detected in the reported prevalence. The ranges of the different B. burgdorferi sensu lato genospecies showed a pattern of high biodiversity between 4°W and 20°E, partially overlapping the area of highest prevalence in ticks. Borrelia afzelii and Borrelia garinii are the dominant species in central Europe (east of ∼25°E), but B. garinii may appear alone at southern latitudes and Borrelia lusitaniae is the main indicator species for meridional territories. PMID:21498767

  13. The Historical Speciation of Mauremys Sensu Lato: Ancestral Area Reconstruction and Interspecific Gene Flow Level Assessment Provide New Insights

    PubMed Central

    Zhou, Huaxing; Jiang, Yuan; Nie, Liuwang; Yin, Huazong; Li, Haifeng; Dong, Xianmei; Zhao, Feifei; Zhang, Huanhuan; Pu, Youguang; Huang, Zhenfeng; Song, Jiaolian; Sun, Entao

    2015-01-01

    Mauremys sensu lato was divided into Mauremys, Chinemys, Ocadia, and Annamemys based on earlier research on morphology. Phylogenetic research on this group has been controversial because of disagreements regarding taxonomy, and the historical speciation is still poorly understood. In this study, 32 individuals of eight species that are widely distributed in Eurasia were collected. The complete mitochondrial (mt) sequences of 14 individuals of eight species were sequenced. Phylogenetic relationships, interspecific divergence times, and ancestral area reconstructions were explored using mt genome data (10,854 bp). Subsequent interspecific gene flow level assessment was performed using five unlinked polymorphic microsatellite loci. The Bayesian and maximum likelihood analyses revealed a paraphyletic relationship among four old genera (Mauremys, Annamemys, Chinemys, and Ocadia) and suggested the four old genera should be merged into the genus (Mauremys). Ancestral area reconstruction and divergence time estimation suggested Southeast Asia may be the area of origin for the common ancestral species of this genus and genetic drift may have played a decisive role in species divergence due to the isolated event of a glacial age. However, M. japonica may have been speciated due to the creation of the island of Japan. The detection of extensive gene flow suggested no vicariance occurred between Asia and Southeast Asia. Inconsistent results between gene flow assessment and phylogenetic analysis revealed the hybrid origin of M. mutica (Southeast Asian). Here ancestral area reconstruction and interspecific gene flow level assessment were first used to explore species origins and evolution of Mauremys sensu lato, which provided new insights on this genus. PMID:26657158

  14. Toxicity of six plant extracts and two pyridone alkaloids from Ricinus communis against the malaria vector Anopheles gambiae

    PubMed Central

    2014-01-01

    Background 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 behaviour especially on how the extracts of such plants impact on the fitness of this vector has not been explored. This study determined the toxicity and larvicidal activity on this vector of extracts from six selected plants found in Kenya and two compounds identified from Ricinus communis: 3-carbonitrile-4-methoxy-N-methyl-2-pyridone (ricinine), and its carboxylic acid derivative 3-carboxy-4-methoxy-N-methyl-2-pyridone, the latter compound being reported for the first time from this plant. Methods Feeding assays tested for toxic effects of extracts from the plants Artemisia afra Jacq. ex Willd, Bidens pilosa L., Parthenium hysterophorus L., Ricinus coummunis L., Senna didymobotrya Fresen. and Tithonia diversifolia Hemsl. on adult females and larvicidal activity was tested against third-instar larvae of Anopheles gambiae s.s. Mortality of larvae and adult females was monitored for three and eight days, respectively; Probit analysis was used to calculate LC50. Survival was analysed with Kaplan-Meier Model. LC-MS was used to identify the pure compounds. Results Of the six plants screened, extracts from T. diversifolia and R. communis were the most toxic against adult female mosquitoes after 7 days of feeding, with LC50 of 1.52 and 2.56 mg/mL respectively. Larvicidal activity of all the extracts increased with the exposure time with the highest mortality recorded for the extract from R. communis after 72 h of exposure (LC50 0.18 mg/mL). Mosquitoes fed on solutions of the pure compounds, 3-carboxy-4-methoxy-N-methyl-2-pyridone and ricinine survived almost as long as those fed on the R. communis extract with mean survival of 4.93 ± 0.07, 4.85 ± 0.07 and 4.50 ± 0.05 days respectively. Conclusions Overall, these findings demonstrate that extracts from the six plant species exhibit

  15. Change in composition of the Anopheles gambiae complex and its possible implications for the transmission of malaria and lymphatic filariasis in north-eastern Tanzania

    PubMed Central

    2012-01-01

    Background A dramatic decline in the incidence of malaria due to Plasmodium falciparum infection in coastal East Africa has recently been reported to be paralleled (or even preceded) by an equally dramatic decline in malaria vector density, despite absence of organized vector control. As part of investigations into possible causes for the change in vector population density, the present study analysed the Anopheles gambiae s.l. sibling species composition in north-eastern Tanzania. Methods The study was in two parts. The first compared current species complex composition in freshly caught An. gambiae s.l. complex from three villages to the composition reported from previous studies carried out 2–4 decades ago in the same villages. The second took advantage of a sample of archived dried An. gambiae s.l. complex specimens collected regularly from a fourth study village since 2005. Both fresh and archived dried specimens were identified to sibling species of the An. gambiae s.l. complex by PCR. The same specimens were moreover examined for Plasmodium falciparum and Wuchereria bancrofti infection by PCR. Results As in earlier studies, An. gambiae s.s., Anopheles merus and Anopheles arabiensis were identified as sibling species found in the area. However, both study parts indicated a marked change in sibling species composition over time. From being by far the most abundant in the past An. gambiae s.s. was now the most rare, whereas An. arabiensis had changed from being the most rare to the most common. P. falciparum infection was rarely detected in the examined specimens (and only in An. arabiensis) whereas W. bancrofti infection was prevalent and detected in all three sibling species. Conclusion The study indicates that a major shift in An. gambiae s.l. sibling species composition has taken place in the study area in recent years. Combined with the earlier reported decline in overall malaria vector density, the study suggests that this decline has been most marked

  16. Pyrethroid resistance/susceptibility and differential urban/rural distribution of Anopheles arabiensis and An. gambiae s.s. malaria vectors in Nigeria and Ghana.

    PubMed

    Kristan, M; Fleischmann, H; della Torre, A; Stich, A; Curtis, C F

    2003-09-01

    Resistance to pyrethroid insecticides and DDT caused by the kdr gene in the malaria vector Anopheles gambiae Giles s.s. (Diptera: Culicidae) has been reported in several West African countries. To test for pyrethroid resistance in two more countries, we sampled populations of the An. gambiae complex from south-western Ghana and from urban and rural localities in Ogun State, south-west Nigeria. Adult mosquitoes, reared from field-collected larvae, were exposed to the WHO-recommended discriminating dosage of exposure for 1 h to DDT 4%, deltamethrin 0.05% or permethrin 0.75% and mortality was recorded 24 h post-exposure. Susceptibility of An. gambiae s.l. to DDT was 94-100% in Ghana and 72-100% in Nigeria, indicating low levels of DDT resistance. Deltamethrin gave the highest mortality rates: 97-100% in Ghana, 95-100% in Nigeria. Ghanaian samples of An. gambiae s.l. were fully susceptible to permethrin, whereas some resistance to permethrin was detected at 4/5 Nigerian localities (percentage mortalities 75, 82, 88, 90 and 100%), with survivors including both An. arabiensis Patton and An. gambiae s.s. identified by PCR assay. Even so, the mean knockdown time was not significantly different from a susceptible reference strain, indicating absence or low frequency of kdr-type resistance. Such low levels of pyrethroid resistance are unlikely to impair the effectiveness of pyrethroid-impregnated bednets against malaria transmission. Among Nigerian samples of An. gambiae s.l., the majority from two urban localities were identified as An. arabiensis, whereas the majority from rural localities were An. gambiae s.s. These findings are consistent with those of M. Coluzzi et al. (1979). Differences of ecological distribution between molecular forms of An. gambiae s.s. were also found, with rural samples almost exclusively of the S-form, whereas the M-form predominated in urban samples. It is suggested that 'urban island' populations of An. arabiensis and of An. gambiae s.s. M

  17. Sensitivity of Anopheles gambiae population dynamics to meteo-hydrological variability: a mechanistic approach

    PubMed Central

    2011-01-01

    Background Mechanistic models play an important role in many biological disciplines, and they can effectively contribute to evaluate the spatial-temporal evolution of mosquito populations, in the light of the increasing knowledge of the crucial driving role on vector dynamics played by meteo-climatic features as well as other physical-biological characteristics of the landscape. Methods In malaria eco-epidemiology landscape components (atmosphere, water bodies, land use) interact with the epidemiological system (interacting populations of vector, human, and parasite). In the background of the eco-epidemiological approach, a mosquito population model is here proposed to evaluate the sensitivity of An. gambiae s.s. population to some peculiar thermal-pluviometric scenarios. The scenarios are obtained perturbing meteorological time series data referred to four Kenyan sites (Nairobi, Nyabondo, Kibwesi, and Malindi) representing four different eco-epidemiological settings. Results Simulations highlight a strong dependence of mosquito population abundance on temperature variation with well-defined site-specific patterns. The upper extreme of thermal perturbation interval (+ 3°C) gives rise to an increase in adult population abundance at Nairobi (+111%) and Nyabondo (+61%), and a decrease at Kibwezi (-2%) and Malindi (-36%). At the lower extreme perturbation (-3°C) is observed a reduction in both immature and adult mosquito population in three sites (Nairobi -74%, Nyabondo -66%, Kibwezi -39%), and an increase in Malindi (+11%). A coherent non-linear pattern of population variation emerges. The maximum rate of variation is +30% population abundance for +1°C of temperature change, but also almost null and negative values are obtained. Mosquitoes are less sensitive to rainfall and both adults and immature populations display a positive quasi-linear response pattern to rainfall variation. Conclusions The non-linear temperature-dependent response is in agreement with the

  18. Chemical composition and insecticidal activity of plant essential oils from Benin against Anopheles gambiae (Giles)

    PubMed Central

    2013-01-01

    Background Insecticide resistance in sub-Saharan Africa and especially in Benin is a major public health issue hindering the control of the malaria vectors. Each Anopheles species has developed a resistance to one or several classes of the insecticides currently in use in the field. Therefore, it is urgent to find alternative compounds to conquer the vector. In this study, the efficacies of essential oils of nine plant species, which are traditionally used to avoid mosquito bites in Benin, were investigated. Methods Essential oils of nine plant species were extracted by hydrodistillation, and their chemical compositions were identified by GC-MS. These oils were tested on susceptible “kisumu” and resistant “ladji-Cotonou” strains of Anopheles gambiae, following WHO test procedures for insecticide resistance monitoring in malaria vector mosquitoes. Results Different chemical compositions were obtained from the essential oils of the plant species. The major constituents identified were as follows: neral and geranial for Cymbopogon citratus, Z-carveol, E-p-mentha-1(7),8-dien-2-ol and E-p-mentha-2,8-dienol for Cymbopogon giganteus, piperitone for Cymbopogon schoenanthus, citronellal and citronellol for Eucalyptus citriodora, p-cymene, caryophyllene oxide and spathulenol for Eucalyptus tereticornis, 3-tetradecanone for Cochlospermum tinctorium and Cochlospermum planchonii, methyl salicylate for Securidaca longepedunculata and ascaridole for Chenopodium ambrosioides. The diagnostic dose was 0.77% for C. citratus, 2.80% for E. tereticornis, 3.37% for E. citriodora, 4.26% for C. ambrosioides, 5.48% for C. schoenanthus and 7.36% for C. giganteus. The highest diagnostic doses were obtained with S. longepedunculata (9.84%), C. tinctorium (11.56%) and C. planchonii (15.22%), compared to permethrin 0.75%. A. gambiae cotonou, which is resistant to pyrethroids, showed significant tolerance to essential oils from C. tinctorium and S. longepedunculata as expected but was

  19. Comparison of carbon dioxide-baited trapping systems for sampling outdoor mosquito populations in Tanzania.

    PubMed

    Mboera LEG; Knols BGJ; Braks MAH; Takken, W

    2000-09-01

    For collecting mosquitoes (Diptera: Culicidae) the outdoor catching efficiency of four types of trapping devices baited with carbon dioxide (CO2, 300 ml/ min) was evaluated and compared in two areas of Tanzania. The types of traps employed were: the CDC miniature trap with the incandescent light bulb switched on or off; electric nets (ENT) and a Counterflow Geometry (CFG) trap. In Njage, southeast Tanzania, Anopheles gambiae Giles sensu stricto was the most abundant of the seven mosquito species obtained, comprising of 74.3% of the total number caught (n=2,171). In Muheza, north-east Tanzania, Culex quinquefasciatus Say was the predominant species (90.9%) among 1,080 caught. At both localities the CFG trap was superior to the CDC trap with light-on or light-off for sampling both An. gambiae and Cx. quinquefasciatus. Efficiency of the CFG trap and ENT were similar for sampling these species of mosquitoes (P > 0.05). However, ENT was superior to the CDC trap with light-off for collecting both species. Significantly more (P < 0.05) Cx. quinquefasciatus were obtained by the CDC trap with light-off than with light-on, especially outdoors. It is concluded that both ENT and the CFG are effective tools for sampling populations of An. gambiae and Cx. quinquefasciatus outdoors. PMID:11016432

  20. Inducible immune factors of the vector mosquito Anopheles gambiae: biochemical purification of a defensin antibacterial peptide and molecular cloning of preprodefensin cDNA.

    PubMed

    Richman, A M; Bulet, P; Hetru, C; Barillas-Mury, C; Hoffmann, J A; Kafalos, F C

    1996-08-01

    Larvae of the mosquito vector of human malaria, Anopheles gambiae, were inoculated with bacteria and extracts were biochemically fractionated by reverse-phase HPLC. Multiple induced polypeptides and antibacterial activities were observed following bacterial infection, including a member of the insect defensin family of antibacterial proteins. A cDNA encoding An. gambiae preprodefensin was isolated using PCR primers based on phylogenetically conserved sequences. The mature peptide is highly conserved, but the signal and propeptide segments are not, relative to corresponding defensin sequences of other insects. Defensin expression is induced in response to bacterial infection, in both adult and larval stages. In contrast, pupae express defensin mRNA constitutively. Defensin expression may prove a valuable molecular marker to monitor the An. gambiae host response to infection by parasitic protozoa of medical importance. PMID:8799739

  1. Indirect evidence that agricultural pesticides select for insecticide resistance in the malaria vector Anopheles gambiae.

    PubMed

    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. PMID:27232122

  2. Identification and characterization of two chitin synthase genes in African malaria mosquito, Anopheles gambiae.

    PubMed

    Zhang, Xin; Zhang, Jianzhen; Park, Yoonseong; Zhu, Kun Yan

    2012-09-01

    Chitin synthase (CHS) represents an attractive target site for combating insect pests as insect growth and development are strictly dependent on precisely tuned chitin biosynthesis and this pathway is absent in humans and other vertebrates. Current knowledge on CHS in insects, especially their structures, functions, and regulations is still very limited. We report the identification and characterization of two chitin synthase genes, AgCHS1 and AgCHS2, in African malaria mosquito, Anopheles gambiae. AgCHS1 and AgCHS2 were predicted to encode proteins of 1,578 and 1,586 amino acid residues, respectively. Their deduced amino acid sequences show high similarities to other insect chitin synthases. Transcriptional analysis indicated that AgCHS1 was expressed in egg, larval, pupal and adult stages whereas AgCHS2 appeared to be expressed at relatively low levels, particularly during the larval stages as examined by reverse transcription (RT)-PCR and real-time quantitative PCR. Relatively high expression was detected in the carcass followed by the foregut and hindgut for AgCHS1, and the foregut (cardia included) followed by the midgut for AgCHS2. Fluorescence in situ hybridization (FISH) and immunohistochemical analysis revealed new information including the localization of the two enzymes in the ommatidia of the compound eyes, and AgCHS2 in the thoracic and abdominal inter-segmental regions of pupal integument. PMID:22683441

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

    PubMed Central

    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

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

    PubMed

    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. PMID:27322614

  5. Interactive cost of Plasmodium infection and insecticide resistance in the malaria vector Anopheles gambiae.

    PubMed

    Alout, Haoues; Dabiré, Roch K; Djogbénou, Luc S; Abate, Luc; Corbel, Vincent; Chandre, Fabrice; Cohuet, Anna

    2016-01-01

    Insecticide resistance raises concerns for the control of vector-borne diseases. However, its impact on parasite transmission could be diverse when considering the ecological interactions between vector and parasite. Thus we investigated the fitness cost associated with insecticide resistance and Plasmodium falciparum infection as well as their interactive cost on Anopheles gambiae survival and fecundity. In absence of infection, we observed a cost on fecundity associated with insecticide resistance. However, survival was higher for mosquito bearing the kdr mutation and equal for those with the ace-1(R) mutation compared to their insecticide susceptible counterparts. Interestingly, Plasmodium infection reduced survival only in the insecticide resistant strains but not in the susceptible one and infection was associated with an increase in fecundity independently of the strain considered. This study provides evidence for a survival cost associated with infection by Plasmodium parasite only in mosquito selected for insecticide resistance. This suggests that the selection of insecticide resistance mutation may have disturbed the interaction between parasites and vectors, resulting in increased cost of infection. Considering the fitness cost as well as other ecological aspects of this natural mosquito-parasite combination is important to predict the epidemiological impact of insecticide resistance. PMID:27432257

  6. Assessment of the kill of Anopheles gambiae by the fumigant insecticide dichlorvos in experimental huts*

    PubMed Central

    Smith, A.; Park, P. O.; Hocking, K. S.

    1964-01-01

    As part of the World Health Organization's programme for the evaluation and testing of new insecticides, different types of dichlorvos dispenser were installed in experimental huts in Tanganyika for study of their effectiveness in killing Anopheles gambiae. It was found that satisfactorily high mosquito mortalities of 75% or more were maintained for one to two months after installation of a dispenser. Mortalities were about 10% higher in huts with grass roofs than in those with mud-lined roofs. The vapour toxicity was similar in the two types of hut, but the results of bio-assay tests on different types of surface showed that there was a residual contact effect of the insecticide as well as the fumigant effect; the lower mortalities in the mud-roofed huts may be due in part to removal or decomposition of the dichlorvos by the mud surface. Measurements of blood pseudo-cholinesterase levels in persons who slept in the experimental huts gave no indication that the dichlorvos had any harmful effect on them. PMID:14267749

  7. SST patterns and dynamics of the southern Senegal-Gambia upwelling center

    NASA Astrophysics Data System (ADS)

    Ndoye, S.; Capet, X.; Estrade, P.; Sow, B.; Dagorne, D.; Lazar, A.; Gaye, A.; Brehmer, P.

    2014-12-01

    The southern end of the Canary current system comprises of an original upwelling center that has so far received little attention, the Southern Senegal-Gambia Upwelling Center (SSUC). We investigate its dynamical functioning by taking advantage of favorable conditions in terms of limited cloud coverage. Analyses and careful examinations of over 1500 satellite images of sea surface temperature scenes contextualized with respect to wind conditions confirm the regularity and stability of the SSUC dynamical functioning (as manifested by the recurrence and persistence of particular SST patterns). The analyses also reveal subtle aspects of its upwelling structure: shelf break cooling of surface waters consistent with internal tide breaking/mixing; complex interplay between local upwelling and the Mauritanian current off the Cape Verde headland; complexity of the inner-shelf/mid shelf frontal transition. The amplitude of the diurnal cycle suggests that large uncertainties exist in the SSUC heat budget. The studies limitations underscore the need for continuous in situ measurement in the SSUC, particularly of winds.

  8. Health Care Utilization and Attitudes Survey: Understanding Diarrheal Disease in Rural Gambia

    PubMed Central

    Saha, Debasish; Akinsola, Adebayo; Sharples, Katrina; Adeyemi, Mitchell O.; Antonio, Martin; Imran, Sayeed; Jasseh, Momodou; Hossain, Mohammad J.; Nasrin, Dilruba; Kotloff, Karen L.; Levine, Myron M.; Hill, Philip C.

    2013-01-01

    Diarrheal disease causes ∼1.34 million deaths per year among children under 5 years of age globally. We conducted a Health Care Utilization and Attitudes Survey of 1,012 primary caregivers of children aged 0–11, 12–23, and 24–59 months randomly selected from a Demographic Surveillance population in rural Gambia. Point prevalence of diarrhea was 7.7% (95% confidence interval [CI] = 6.1–9.8); 23.3% had diarrhea within the previous 2 weeks. Caregivers of 81.5% of children with diarrhea sought healthcare outside their home, but only 48.4% of them visited a health center. Only 17.0% (95% CI = 12.1–23.2) of children with diarrhea received oral rehydration solution (ORS) at home. Abbreviated surveys conducted on six occasions over the subsequent 2 years showed no change in prevalence or treatment-seeking behavior. Diarrhea remains a significant problem in rural young Gambian children. Encouraging care-seeking behavior at health centers and promoting ORS use can reduce mortality and morbidity in this population. PMID:23629926

  9. The Demographic Transition Influences Variance in Fitness and Selection on Height and BMI in Rural Gambia

    PubMed Central

    Courtiol, Alexandre; Rickard, Ian J.; Lummaa, Virpi; Prentice, Andrew M.; Fulford, Anthony J.C.; Stearns, Stephen C.

    2013-01-01

    Summary Recent human history is marked by demographic transitions characterized by declines in mortality and fertility [1]. By influencing the variance in those fitness components, demographic transitions can affect selection on other traits [2]. Parallel to changes in selection triggered by demography per se, relationships between fitness and anthropometric traits are also expected to change due to modification of the environment. Here we explore for the first time these two main evolutionary consequences of demographic transitions using a unique data set containing survival, fertility, and anthropometric data for thousands of women in rural Gambia from 1956–2010 [3]. We show how the demographic transition influenced directional selection on height and body mass index (BMI). We observed a change in selection for both traits mediated by variation in fertility: selection initially favored short females with high BMI values but shifted across the demographic transition to favor tall females with low BMI values. We demonstrate that these differences resulted both from changes in fitness variance that shape the strength of selection and from shifts in selective pressures triggered by environmental changes. These results suggest that demographic and environmental trends encountered by current human populations worldwide are likely to modify, but not stop, natural selection in humans. PMID:23623548

  10. Kin influence on the decision to start using modern contraception: A longitudinal study from rural Gambia.

    PubMed

    Mace, Ruth; Colleran, Heidi

    2009-01-01

    In earlier work in rural Gambia, we found that kin influence reproductive success: matrilineal kin, especially mothers, maternal grandmothers and unmarried older sisters all helped to promote the survival and nutrition of young children; in contrast patrilineal kin, especially husband's mother, promoted fertility. These differing influences of maternal and paternal lineage are predicted on the basis of kin selection and sexual conflict theory, because the costs of reproduction fall more heavily on the mother than the father. These studies covered the period 1950-1975, when this population was essentially "natural fertility, natural mortality." It is not possible to tell whether these effects were due to kin influencing active reproductive decision-making, or due to indirect effects such as kin improving nutrition by helping. Since 1976, modern contraception has become available in this community. In an analysis of the behavioral ecology of the decision to start using modern contraception, we found that high parity for your age was a key determinant of the decision, as was village and calendar year. Here, we examine whether the presence or absence of kin and also whether the contraceptive status of kin influenced the decision to start using contraception. We find little evidence that kin directly influence contraceptive uptake, either by their presence/absence or as models for social learning. However, death of a first husband (i.e., widowhood) does accelerate contraceptive uptake. We discuss our results from an evolutionary demography perspective, in particular regarding theories of sexual conflict, biased cultural transmission, and social learning. PMID:19418529

  11. Transthoracic lung aspiration for the aetiological diagnosis of pneumonia: 25 years of experience from The Gambia.

    PubMed

    Ideh, R C; Howie, S R C; Ebruke, B; Secka, O; Greenwood, B M; Adegbola, R A; Corrah, T

    2011-06-01

    Pneumonia remains the leading cause of death in young children worldwide. Global pneumonia control depends on a good understanding of the aetiology of pneumonia. Percutaneous transthoracic aspiration culture is much more sensitive than blood culture in identifying the aetiological agents of pneumonia. However, the procedure is not widely practised because of lack of familiarity with it and concerns about potential adverse events. We review the diagnostic usefulness and safety of this procedure over 25 years of its use in research and routine practice at the UK Medical Research Council (MRC), The Gambia, and give a detailed description of the procedure itself. Published materials were identified from the MRC's publication database and systematic searches using the PubMed/Medline and Google search engines. Data from a current pneumonia aetiology study in the unit are included together with clinical experience of staff practising at the unit over the period covered in this review. A minimum of 500 lung aspirates were performed over the period of review. Lung aspiration produces a greater yield of diagnostic bacterial isolates than blood culture. It is especially valuable clinically when pathogens not covered by standard empirical antibiotic treatment, such as Mycobacterium tuberculosis and Staphylococcus aureus, are identified. There have been no deaths following the procedure in our setting and a low rate of other complications, all transient. Lung aspiration is currently the most sensitive method for diagnosing pneumonia in children. With appropriate training and precautions it can be safely used for routine diagnosis in suitable referral hospitals. PMID:21477423

  12. Comparative Genome and Proteome Analysis of Anopheles gambiae and Drosophila melanogaster

    NASA Astrophysics Data System (ADS)

    Zdobnov, Evgeny M.; von Mering, Christian; Letunic, Ivica; Torrents, David; Suyama, Mikita; Copley, Richard R.; Christophides, George K.; Thomasova, Dana; Holt, Robert A.; Subramanian, G. Mani; Mueller, Hans-Michael; Dimopoulos, George; Law, John H.; Wells, Michael A.; Birney, Ewan; Charlab, Rosane; Halpern, Aaron L.; Kokoza, Elena; Kraft, Cheryl L.; Lai, Zhongwu; Lewis, Suzanna; Louis, Christos; Barillas-Mury, Carolina; Nusskern, Deborah; Rubin, Gerald M.; Salzberg, Steven L.; Sutton, Granger G.; Topalis, Pantelis; Wides, Ron; Wincker, Patrick; Yandell, Mark; Collins, Frank H.; Ribeiro, Jose; Gelbart, William M.; Kafatos, Fotis C.; Bork, Peer

    2002-10-01

    Comparison of the genomes and proteomes of the two diptera Anopheles gambiae and Drosophila melanogaster, which diverged about 250 million years ago, reveals considerable similarities. However, numerous differences are also observed; some of these must reflect the selection and subsequent adaptation associated with different ecologies and life strategies. Almost half of the genes in both genomes are interpreted as orthologs and show an average sequence identity of about 56%, which is slightly lower than that observed between the orthologs of the pufferfish and human (diverged about 450 million years ago). This indicates that these two insects diverged considerably faster than vertebrates. Aligned sequences reveal that orthologous genes have retained only half of their intron/exon structure, indicating that intron gains or losses have occurred at a rate of about one per gene per 125 million years. Chromosomal arms exhibit significant remnants of homology between the two species, although only 34% of the genes colocalize in small ``microsyntenic'' clusters, and major interarm transfers as well as intra-arm shuffling of gene order are detected.

  13. Interactive cost of Plasmodium infection and insecticide resistance in the malaria vector Anopheles gambiae

    PubMed Central

    Alout, Haoues; Dabiré, Roch K.; Djogbénou, Luc S.; Abate, Luc; Corbel, Vincent; Chandre, Fabrice; Cohuet, Anna

    2016-01-01

    Insecticide resistance raises concerns for the control of vector-borne diseases. However, its impact on parasite transmission could be diverse when considering the ecological interactions between vector and parasite. Thus we investigated the fitness cost associated with insecticide resistance and Plasmodium falciparum infection as well as their interactive cost on Anopheles gambiae survival and fecundity. In absence of infection, we observed a cost on fecundity associated with insecticide resistance. However, survival was higher for mosquito bearing the kdr mutation and equal for those with the ace-1R mutation compared to their insecticide susceptible counterparts. Interestingly, Plasmodium infection reduced survival only in the insecticide resistant strains but not in the susceptible one and infection was associated with an increase in fecundity independently of the strain considered. This study provides evidence for a survival cost associated with infection by Plasmodium parasite only in mosquito selected for insecticide resistance. This suggests that the selection of insecticide resistance mutation may have disturbed the interaction between parasites and vectors, resulting in increased cost of infection. Considering the fitness cost as well as other ecological aspects of this natural mosquito-parasite combination is important to predict the epidemiological impact of insecticide resistance. PMID:27432257

  14. Early life nutritional programming of health and disease in The Gambia.

    PubMed

    Moore, S E

    2016-04-01

    Exposures during the early life (periconceptional, prenatal and early postnatal) period are increasingly recognized as playing an important role in the aetiology of chronic non-communicable diseases (NCD), including coronary heart disease, stroke, hypertension, Type 2 diabetes and osteoporosis. The 'Developmental Origins of Health and Disease' (DOHaD) hypothesis states that these disorders originate through unbalanced nutrition early in life and risk is highest when there is a 'mismatch' between the early- and later-life environments. Thus, the DOHaD hypothesis would predict highest risk in countries where an excess of infants are born with low birth weight and where there is a rapid transition to nutritional adequacy or excess in adulthood. Here, I will review data from work conducted in rural Gambia, West Africa. Using demographic data dating back to the 1940s, the follow-up of randomized controlled trials of nutritional supplementation in pregnancy and the 'experiment of nature' that seasonality in this region provides, we have investigated the DOHaD hypothesis in a population with high rates of maternal and infant under-nutrition, a high burden from infectious disease, and an emerging risk of NCDs. PMID:26503192

  15. Site-specific genetic engineering of the Anopheles gambiae Y chromosome.

    PubMed

    Bernardini, Federica; Galizi, Roberto; Menichelli, Miriam; Papathanos, Philippos-Aris; Dritsou, Vicky; Marois, Eric; Crisanti, Andrea; Windbichler, Nikolai

    2014-05-27

    Despite its function in sex determination and its role in driving genome evolution, the Y chromosome remains poorly understood in most species. Y chromosomes are gene-poor, repeat-rich and largely heterochromatic and therefore represent a difficult target for genetic engineering. The Y chromosome of the human malaria vector Anopheles gambiae appears to be involved in sex determination although very little is known about both its structure and function. Here, we characterize a transgenic strain of this mosquito species, obtained by transposon-mediated integration of a transgene construct onto the Y chromosome. Using meganuclease-induced homologous repair we introduce a site-specific recombination signal onto the Y chromosome and show that the resulting docking line can be used for secondary integration. To demonstrate its utility, we study the activity of a germ-line-specific promoter when located on the Y chromosome. We also show that Y-linked fluorescent transgenes allow automated sex separation of this important vector species, providing the means to generate large single-sex populations. Our findings will aid studies of sex chromosome function and enable the development of male-exclusive genetic traits for vector control. PMID:24821795

  16. Survivorship and distribution of immature Anopheles gambiae s.l. (Diptera: Culicidae) in Banambani village, Mali.

    PubMed

    Edillo, Frances E; Touré, Yeya T; Lanzaro, Gregory C; Dolo, Guimogo; Taylor, Charles E

    2004-05-01

    We observed the survivorship and distribution of larvae and pupae of Anopheles gambiae s.l. Giles immature stages in three habitats (rock pools, swamp, and puddles) in Banambani village. Mali, West Africa, during the mid-rainy season of 2000. Horizontal life tables were constructed for immatures in the laboratory. Times spent in the various immature stages were determined, and laboratory survival was measured. Vertical life tables were obtained from each habitat. We found large day-to-day variation for age class composition within habitats across days. The swamp samples had small but statistically significant different distributions in some instar stages compared with rock pools and puddles as affected by precipitation history. There were obviously unstable age distributions in the swamp and puddles and to some extent in rock pools. There were more individuals in some later age classes than in earlier ones. The daily survival estimates using an exponential decay model were 0.807 in rock pools, 0.899 in the swamp, 0.818 in puddles, and 0.863 in the overall village. Possible reasons for the departure from stable age distribution were cannibalism, predation and other complex interactions, rainfall effects, sampling bias, and differences in physicochemical properties of the water in the habitats. PMID:15185933

  17. Successful transfer of frozen N'Dama embryos from the Gambia to Kenya.

    PubMed

    Jordt, T; Mahon, G D; Touray, B N; Ngulo, W K; Morrison, W I; Rawle, J; Murray, M

    1986-05-01

    Frozen embryos from N'Dama cattle were successfully transferred from The Gambia to Kenya. Of the 26 N'Dama cows used 12 were successfully programmed to superovulate and of these seven produced 30 embryos that were collected seven days after oestrus/service. Five N'Dama bulls were used for natural service. In Kenya 29 embryos were implanted into 29 Boran heifers seven days (+/- 1) after the induction of synchronised oestrus. Eleven pregnancies were established and after one abortion of unknown aetiology at seven and a half months five female and five male calves were born and subsequently reared. During programming the N'Dama cows showed prolonged anoestrus leading to the necessity of oestrus induction using intravaginal progesterone releasing coils; pregnant mare serum gonadotrophin gave better superovulation than follicle stimulating hormone. One N'Dama bull proved to be subfertile. The success of the project has demonstrated the potential of this technique to make disease-free N'Dama available for research purposes and for the promotion of livestock development programmes in tsetse-infested areas using trypanotolerant cattle. PMID:3738996

  18. Pantropic retroviral vectors integrate and express in cells of the malaria mosquito, Anopheles gambiae.

    PubMed Central

    Matsubara, T; Beeman, R W; Shike, H; Besansky, N J; Mukabayire, O; Higgs, S; James, A A; Burns, J C

    1996-01-01

    The lack of efficient mechanisms for stable genetic transformation of medically important insects, such as anopheline mosquitoes, is the single most important impediment to progress in identifying novel control strategies. Currently available techniques for foreign gene expression in insect cells in culture lack the benefit of stable inheritance conferred by integration. To overcome this problem, a new class of pantropic retroviral vectors has been developed in which the amphotropic envelope is completely replaced by the G glycoprotein of vesicular stomatitis virus. The broadened host cell range of these particles allowed successful entry, integration, and expression of heterologous genes in cultured cells of Anopheles gambiae, the principle mosquito vector responsible for the transmission of over 100 million cases of malaria each year. Mosquito cells in culture infected with a pantropic vector expressing hygromycin phosphotransferase from the Drosophila hsp70 promoter were resistant to the antibiotic hygromycin B. Integrated provirus was detected in infected mosquito cell clones grown in selective media. Thus, pantropic retroviral vectors hold promise as a transformation system for mosquitoes in vivo. Images Fig. 2 Fig. 4 Fig. 5 PMID:8650240

  19. An Integrated Genetic Map of the African Human Malaria Vector Mosquito, Anopheles Gambiae

    PubMed Central

    Zheng, L.; Benedict, M. Q.; Cornel, A. J.; Collins, F. H.; Kafatos, F. C.

    1996-01-01

    We present a genetic map based on microsatellite polymorphisms for the African human malaria vector, Anopheles gambiae. Polymorphisms in laboratory strains were detected for 89% of the tested microsatellite markers. Genotyping was performed for individual mosquitoes from 13 backcross families that included 679 progeny. Three linkage groups were identified, corresponding to the three chromosomes. We added 22 new markers to the existing X chromosome map, for a total of 46 microsatellite markers spanning a distance of 48.9 cM. The second chromosome has 57 and the third 28 microsatellite markers spanning a distance of 72.4 and 93.7 cM, respectively. The overall average distance between markers is 1.6 cM (or 1.1, 1.2, and 3.2 cM for the X, second, and third chromosomes, respectively). In addition to the 131 microsatellite markers, the current map also includes a biochemical selectable marker, Dieldrin resistance (Dl), on the second chromosome and five visible markers, pink-eye (p) and white (w) on the X, collarless (c) and lunate (lu) on the second, and red-eye (r) on the third. The cytogenetic locations on the nurse cell polytene chromosomes have been determined for 47 markers, making this map an integrated tool for cytogenetic, genetic, and molecular analysis. PMID:8725240

  20. Comparative genome and proteome analysis of Anopheles gambiae and Drosophila melanogaster.

    PubMed

    Zdobnov, Evgeny M; von Mering, Christian; Letunic, Ivica; Torrents, David; Suyama, Mikita; Copley, Richard R; Christophides, George K; Thomasova, Dana; Holt, Robert A; Subramanian, G Mani; Mueller, Hans-Michael; Dimopoulos, George; Law, John H; Wells, Michael A; Birney, Ewan; Charlab, Rosane; Halpern, Aaron L; Kokoza, Elena; Kraft, Cheryl L; Lai, Zhongwu; Lewis, Suzanna; Louis, Christos; Barillas-Mury, Carolina; Nusskern, Deborah; Rubin, Gerald M; Salzberg, Steven L; Sutton, Granger G; Topalis, Pantelis; Wides, Ron; Wincker, Patrick; Yandell, Mark; Collins, Frank H; Ribeiro, Jose; Gelbart, William M; Kafatos, Fotis C; Bork, Peer

    2002-10-01

    Comparison of the genomes and proteomes of the two diptera Anopheles gambiae and Drosophila melanogaster, which diverged about 250 million years ago, reveals considerable similarities. However, numerous differences are also observed; some of these must reflect the selection and subsequent adaptation associated with different ecologies and life strategies. Almost half of the genes in both genomes are interpreted as orthologs and show an average sequence identity of about 56%, which is slightly lower than that observed between the orthologs of the pufferfish and human (diverged about 450 million years ago). This indicates that these two insects diverged considerably faster than vertebrates. Aligned sequences reveal that orthologous genes have retained only half of their intron/exon structure, indicating that intron gains or losses have occurred at a rate of about one per gene per 125 million years. Chromosomal arms exhibit significant remnants of homology between the two species, although only 34% of the genes colocalize in small "microsyntenic" clusters, and major interarm transfers as well as intra-arm shuffling of gene order are detected. PMID:12364792

  1. Gene expression patterns associated with blood-feeding in the malaria mosquito Anopheles gambiae

    PubMed Central

    Dana, Ali N; Hong, Young S; Kern, Marcia K; Hillenmeyer, Maureen E; Harker, Brent W; Lobo, Neil F; Hogan, James R; Romans, Patricia; Collins, Frank H

    2005-01-01

    Background Blood feeding, or hematophagy, is a behavior exhibited by female mosquitoes required both for reproduction and for transmission of pathogens. We determined the expression patterns of 3,068 ESTs, representing ~2,000 unique gene transcripts using cDNA microarrays in adult female Anopheles gambiae at selected times during the first two days following blood ingestion, at 5 and 30 min during a 40 minute blood meal and at 0, 1, 3, 5, 12, 16, 24 and 48 hours after completion of the blood meal and compared their expression to transcript levels in mosquitoes with access only to a sugar solution. Results In blood-fed mosquitoes, 413 unique transcripts, approximately 25% of the total, were expressed at least two-fold above or below their levels in the sugar-fed mosquitoes, at one or more time points. These differentially expressed gene products were clustered using k-means clustering into Early Genes, Middle Genes, and Late Genes, containing 144, 130, and 139 unique transcripts, respectively. Several genes from each group were analyzed by quantitative real-time PCR in order to validate the microarray results. Conclusion The expression patterns and annotation of the genes in these three groups (Early, Middle, and Late genes) are discussed in the context of female mosquitoes' physiological responses to blood feeding, including blood digestion, peritrophic matrix formation, egg development, and immunity. PMID:15651988

  2. THE SALIVARY TRANSCRIPTOME OF Anopheles gambiae (DIPTERA: CULICIDAE) LARVAE: A MICROARRAY-BASED ANALYSIS

    PubMed Central

    Neira Oviedo, M.; Ribeiro, J.M.C.; Heyland, A.; VanEkeris, L.; Moroz, T.; Linser, P.J.

    2009-01-01

    In spite of the many recent developments in the field of vector sialomics, the salivary glands of larval mosquitoes have been largely unexplored. We used whole-transcriptome microarray analysis to create a gene-expression profile of the salivary gland tissue of fourth-instar Anopheles gambiae larvae, and compare it to the gene-expression profile of a matching group of whole larvae. We identified a total of 221 probes with expression values that were (a) significantly enriched in the salivary glands, and (b) sufficiently annotated as to allow the prediction of the presence/absence of signal peptides in their corresponding gene products. Based on available annotation of the protein sequences associated with these probes, we propose that the main roles of larval salivary secretions include: (a) immune response, (b) mouthpart lubrication, (c) nutrient metabolism, and (d) xenobiotic detoxification. Other highlights of the study include the cloning of a transcript encoding a previously unknown salivary defensin (AgDef5), the confirmation of mucus secretion by the larval salivary glands, and the first report of salivary lipocalins in the Culicidae. PMID:19328852

  3. Determinants of Appropriate Child Health and Nutrition Practices among Women in Rural Gambia

    PubMed Central

    Prentice, Andrew; Plugge, Emma; Nweneka, Chidi

    2010-01-01

    Health education and awareness involves providing knowledge about causes of illness and choices to promote a change in individual behaviour and, thus, improves survival of individuals. Studies have, however, shown that improved knowledge and awareness is not always translated into appropriate actions. This study aimed at exploring the factors determining mothers’ choices of appropriate child health and nutrition practices in the Gambia. Eight focus-group discussions (FGDs) were held with 63 women whose children had been seen at the Keneba MRC Clinic within the 12 months preceding the study. The FGDs were analyzed using a thematic framework. Gender inequality, presence or absence of support networks, alternative explanatory models of malnutrition, and poverty were identified as the main factors that would determine the ability of a mother to practise what she knows about child health and nutrition. The findings highlight the need to consider the broader social, cultural and economic factors, including the value of involving men in childcare, when designing nutritional interventions. PMID:20411680

  4. Anthropogenic Habitat Disturbance and Ecological Divergence between Incipient Species of the Malaria Mosquito Anopheles gambiae

    PubMed Central

    Kamdem, Colince; Tene Fossog, Billy; Simard, Frédéric; Etouna, Joachim; Ndo, Cyrille; Kengne, Pierre; Boussès, Philippe; Etoa, François-Xavier; Awono-Ambene, Parfait; Fontenille, Didier; Antonio-Nkondjio, Christophe; Besansky, Nora J.; Costantini, Carlo

    2012-01-01

    Background Anthropogenic habitat disturbance is a prime cause in the current trend of the Earth’s reduction in biodiversity. Here we show that the human footprint on the Central African rainforest, which is resulting in deforestation and growth of densely populated urban agglomerates, is associated to ecological divergence and cryptic speciation leading to adaptive radiation within the major malaria mosquito Anopheles gambiae. Methodology/Principal Findings In southern Cameroon, the frequency of two molecular forms–M and S–among which reproductive isolation is strong but still incomplete, was correlated to an index of urbanisation extracted from remotely sensed data, expressed as the proportion of built-up surface in each sampling unit. The two forms markedly segregated along an urbanisation gradient forming a bimodal cline of ∼6-km width: the S form was exclusive to the rural habitat, whereas only the M form was present in the core of densely urbanised settings, co-occurring at times in the same polluted larval habitats of the southern house mosquito Culex quinquefasciatus–a species association that was not historically recorded before. Conclusions/Significance Our results indicate that when humans create novel habitats and ecological heterogeneities, they can provide evolutionary opportunities for rapid adaptive niche shifts associated with lineage divergence, whose consequences upon malaria transmission might be significant. PMID:22745756

  5. Carbamate and pyrethroid resistance in the akron strain of Anopheles gambiae.

    PubMed

    Mutunga, James M; Anderson, Troy D; Craft, Derek T; Gross, Aaron D; Swale, Daniel R; Tong, Fan; Wong, Dawn M; Carlier, Paul R; Bloomquist, Jeffrey R

    2015-06-01

    Insecticide resistance in the malaria vector, Anopheles gambiae, is a serious problem, epitomized by the multi-resistant Akron strain, originally isolated in the country of Benin. Here we report resistance in this strain to pyrethroids and DDT (13-fold to 35-fold compared to the susceptible G3 strain), but surprisingly little resistance to etofenprox, a compound sometimes described as a "pseudo-pyrethroid." There was also strong resistance to topically-applied commercial carbamates (45-fold to 81-fold), except for the oximes aldicarb and methomyl. Biochemical assays showed enhanced cytochrome P450 monooxygenase and carboxylesterase activity, but not that of glutathione-S-transferase. A series of substituted α,α,α,-trifluoroacetophenone oxime methylcarbamates were evaluated for enzyme inhibition potency and toxicity against G3 and Akron mosquitoes. The compound bearing an unsubstituted phenyl ring showed the greatest toxicity to mosquitoes of both strains. Low cross resistance in Akron was retained by all analogs in the series. Kinetic analysis of acetylcholinesterase activity and its inhibition by insecticides in the G3 strain showed inactivation rate constants greater than that of propoxur, and against Akron enzyme inactivation rate constants similar to that of aldicarb. However, inactivation rate constants against recombinant human AChE were essentially identical to that of the G3 strain. Thus, the acetophenone oxime carbamates described here, though potent insecticides that control resistant Akron mosquitoes, require further structural modification to attain acceptable selectivity and human safety. PMID:26047119

  6. Carbamate and Pyrethroid Resistance in the Akron Strain of Anopheles gambiae

    PubMed Central

    Mutunga, James M.; Anderson, Troy D.; Craft, Derek T.; Gross, Aaron D.; Swale, Daniel R.; Tong, Fan; Wong, Dawn M.; Carlier, Paul R.; Bloomquist, Jeffrey R.

    2015-01-01

    Insecticide resistance in the malaria vector, Anopheles gambiae is a serious problem, epitomized by the multi-resistant Akron strain, originally isolated in the country of Benin. Here we report resistance in this strain to pyrethroids and DDT (13-fold to 35-fold compared to the susceptible G3 strain), but surprisingly little resistance to etofenprox, a compound sometimes described as a “pseudo-pyrethroid.” There was also strong resistance to topically-applied commercial carbamates (45-fold to 81-fold), except for the oximes aldicarb and methomyl. Biochemical assays showed enhanced cytochrome P450 monooxygenase and carboxylesterase activity, but not that of glutathione-S-transferase. A series of substituted α,α,α,-trifluoroacetophenone oxime methylcarbamates were evaluated for enzyme inhibition potency and toxicity against G3 and Akron mosquitoes. The compound bearing an unsubstituted phenyl ring showed the greatest toxicity to mosquitoes of both strains. Low cross resistance in Akron was retained by all analogs in the series. Kinetic analysis of acetylcholinesterase activity and its inhibition by insecticides in the G3 strain showed inactivation rate constants greater than that of propoxur, and against Akron enzyme inactivation rate constants similar to that of aldicarb. However, inactivation rate constants against recombinant human AChE were essentially identical to that of the G3 strain. Thus, the acetophenone oxime carbamates described here, though potent insecticides that control resistant Akron mosquitoes, require further structural modification to attain acceptable selectivity and human safety. PMID:26047119

  7. Human sweat and 2-oxopentanoic acid elicit a landing response from Anopheles gambiae.

    PubMed

    Healy, T P; Copland, M J

    2000-06-01

    A wind tunnel bioassay and video to observe mosquitoes landing on heated glass cylinders were used to test sweat and some derivatives for responses of Anopheles gambiae Giles (Diptera: Culicidae), a highly anthropophilic African species of malaria vector. Filter papers impregnated with human sweat and a diethyl ether extract from the filter papers elicited significantly more landings than a water control (P<0.001). The concentration of lactic acid in the extract was determined by GLC assay, but bioassays of an equivalent dose of lactic acid (from a commercial supplier) did not elicit landings. Chemical analysis of the extract by combined GLC/mass spectrometry indicated the presence of 73 compounds, of which 40 were tentatively identified. The major components of the extract were aliphatic carboxylic acids. An artificial blend of 22 carboxylic acids did not elicit landings. Bioassays of 2-oxopentanoic acid elicited significantly more, landings (P<0.001). The possible importance of oxo-carboxylic acids for host-seeking by anthropophilic mosquitoes is discussed and their use for trapping is suggested. PMID:10872864

  8. Transport of carbon, nitrogen, phosphorus, and major solutes in the Gambia River, West Africa

    SciTech Connect

    Lesack, L.F.W.; Hecky, R.E.; Melack, J.M.

    1984-07-01

    Transport of solutes and particulate materials and their variation with discharge were studied for 1 year (July 1980-June 1981) in the Gambia River in the tropical savanna of West Africa. The water is a dilute solution of SiO/sub 2/ and HCO/sub 3//sup -/. Na/sup +/, K/sup +/, Cl/sup -/, and total dissolved nitrogen showed no significant relation with discharge. Ca/sup 2 +/, Mg/sup 2 +/, HCO/sub 3//sup -/, conductivity, and SO/sub 4//sup 2 -/ decreased as discharge increased, while total dissolved phosphorus increased with discharge. After an initial increase SiO/sub 2/ was independent of discharge. Dissolved organic carbon displayed counterclockwise hysteresis with rising and falling discharge. Particulate phosphorus and total particulate materials displayed clockwise hysteresis. Total transport amounted to 9.66 t x km/sup -2/ x yr/sup -1/. The transport rates of both dissolved and particulate organic C are among the lowest ever reported. The low transport of total particulates and solutes is attributed to lack of relief and the lithology of the catchment.

  9. Factors affecting immunogenicity of BCG in infants, a study in Malawi, The Gambia and the UK

    PubMed Central

    2014-01-01

    Background BCG immunogenicity in infants differs between populations and these differences have been attributed to various factors. In this study, the influence of geographical location, season of birth, timing of vaccination, micronutrient status (zinc) and inflammatory status (C-reactive protein, CRP) were assessed. Methods Immunogenicity was assessed by cytokine signature in culture supernatants from diluted whole blood samples stimulated with M. tuberculosis PPD, using a multiplex bead assay. Results were correlated with the plasma zinc and CRP concentrations at the time of sampling, and with interview and household data. BCG vaccinated infants were recruited in Malawi, The Gambia and the UK. Results In Malawi, infants vaccinated within the first week after birth showed lower production of most cytokines measured than those vaccinated later. The number of cytokines showing significant differences between Malawian and Gambian infants decreased after adjusting for season of birth. In Malawi, a proportion of infants had zinc deficiency and elevated plasma CRP (>10 mg/L), but neither zinc deficiency nor high CRP was associated with production of any of the cytokines measured. Conclusions The cytokine/chemokine signatures observed in response to M. tuberculosis PPD in infants at 3 months post BCG vaccination were affected by geographical location, season of birth, and timing of vaccination but not associated with the concentration of plasma zinc or inflammatory status. These factors should be considered in future trials of new TB vaccines. PMID:24708690

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

    PubMed Central

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

    2015-01-01

    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. PMID:25225164

  11. Population genetics of Plasmodium resistance genes in Anopheles gambiae: no evidence for strong selection.

    PubMed

    Obbard, D J; Linton, Y-M; Jiggins, F M; Yan, G; Little, T J

    2007-08-01

    Anopheles mosquitoes are the primary vectors for malaria in Africa, transmitting the disease to more than 100 million people annually. Recent functional studies have revealed mosquito genes that are crucial for Plasmodium development, but there is presently little understanding of which genes mediate vector competence in the wild, or evolve in response to parasite-mediated selection. Here, we use population genetic approaches to study the strength and mode of natural selection on a suite of mosquito immune system genes, CTL4, CTLMA2, LRIM1, and APL2 (LRRD7), which have been shown to affect Plasmodium development in functional studies. We sampled these genes from two African populations of An. gambiae s.s., along with several closely related species, and conclude that there is no evidence for either strong directional or balancing selection on these genes. We highlight a number of challenges that need to be met in order to apply population genetic tests for selection in Anopheles mosquitoes; in particular the dearth of suitable outgroup species and the potential difficulties that arise when working within a closely-related species complex. PMID:17688548

  12. Epidemiology of paediatric surgical admissions to a government referral hospital in the Gambia.

    PubMed Central

    Bickler, S. W.; Sanno-Duanda, B.

    2000-01-01

    INTRODUCTION: There is a paucity of published data on the type of conditions that require surgery among children in sub-Saharan Africa. Such information is necessary for assessing the impact of such conditions on child health and for setting priorities to improve paediatric surgical care. METHODS: Described in the article is a 29-month prospective study of all children aged < 15 years who were admitted to a government referral hospital in the Gambia from January 1996 to May 1998. RESULTS: A total of 1726 children were admitted with surgical problems. Surgical patients accounted for 11.3% of paediatric admissions and 34,625 total inpatient days. The most common admission diagnoses were injuries (46.9%), congenital anomalies (24.3%), and infections requiring surgery (14.5%). The diagnoses that accounted for the greatest number of inpatient days were burns (18.8%), osteomyelitis (15.4%), fractures (12.7%), soft tissue injuries (3.9%), and head injuries (3.4%). Gambian children were rarely admitted for appendicitis and never admitted for hypertrophic pyloric stenosis. The leading causes of surgical deaths were burns, congenital anomalies, and injuries other than burns. DISCUSSION: Prevention of childhood injuries and better trauma management, especially at the primary and secondary health care levels, should be the priorities for improving paediatric surgical care in sub-Saharan Africa. Surgical care of children should be considered an essential component of child health programmes in developing countries. PMID:11143193

  13. The neurotransmitters serotonin and glutamate accelerate the heart rate of the mosquito Anopheles gambiae.

    PubMed

    Hillyer, Julián F; Estévez-Lao, Tania Y; Mirzai, Homa E

    2015-10-01

    Serotonin and glutamate are neurotransmitters that in insects are involved in diverse physiological processes. Both serotonin and glutamate have been shown to modulate the physiology of the dorsal vessel of some insects, yet until the present study, their activity in mosquitoes remained unknown. To test whether serotonin or glutamate regulate dorsal vessel physiology in the African malaria mosquito, Anopheles gambiae, live mosquitoes were restrained, and a video of the contracting heart (the abdominal portion of the dorsal vessel) was acquired. These adult female mosquitoes were then injected with various amounts of serotonin, glutamate, or a control vehicle solution, and additional videos were acquired at 2 and 10 min post-treatment. Comparison of the videos taken before and after treatment revealed that serotonin accelerates the frequency of heart contractions, with the cardioacceleration being significantly more pronounced when the wave-like contractions of cardiac muscle propagate in the anterograde direction (toward the head). Comparison of the videos taken before and after treatment with glutamate revealed that this molecule is also cardioacceleratory. However, unlike serotonin, the activity of glutamate does not depend on whether the contractions propagate in the anterograde or the retrograde (toward the posterior of the abdomen) directions. Serotonin or glutamate induces a minor change or no change in the percentage of contractions and the percentage of the time that the heart contracts in the anterograde or the retrograde directions. In summary, this study shows that the neurotransmitters serotonin and glutamate increase the heart contraction rate of mosquitoes. PMID:26099947

  14. How the Malaria Vector Anopheles gambiae Adapts to the Use of Insecticide-Treated Nets by African Populations

    PubMed Central

    Ndiath, Mamadou Ousmane; Mazenot, Catherine; Sokhna, Cheikh; Trape, Jean-François

    2014-01-01

    Background Insecticide treated bed nets have been recommended and proven efficient as a measure to protect African populations from malaria mosquito vector Anopheles spp. This study evaluates the consequences of bed nets use on vectors resistance to insecticides, their feeding behavior and malaria transmission in Dielmo village, Senegal, were LLINs were offered to all villagers in July 2008. Methods Adult mosquitoes were collected monthly from January 2006 to December 2011 by human landing catches (HLC) and by pyrethroid spray catches (PCS). A randomly selected sub-sample of 15–20% of An. gambiae s.l. collected each month was used to investigate the molecular forms of the An. gambiae complex, kdr mutations, and Plasmodium falciparum circumsporozoite (CSP) rate. Malaria prevalence and gametocytaemia in Dielmo villagers were measured quarterly. Results Insecticide susceptible mosquitoes (wild kdr genotype) presented a reduced lifespan after LLINs implementation but they rapidly adapted their feeding behavior, becoming more exophageous and zoophilic, and biting earlier during the night. In the meantime, insecticide-resistant specimens (kdr L1014F genotype) increased in frequency in the population, with an unchanged lifespan and feeding behaviour. P. falciparum prevalence and gametocyte rate in villagers decreased dramatically after LLINs deployment. Malaria infection rate tended to zero in susceptible mosquitoes whereas the infection rate increased markedly in the kdr homozygote mosquitoes. Conclusion Dramatic changes in vector populations and their behavior occurred after the deployment of LLINs due to the extraordinary adaptative skills of An. gambiae s. l. mosquitoes. However, despite the increasing proportion of insecticide resistant mosquitoes and their almost exclusive responsibility in malaria transmission, the P. falciparum gametocyte reservoir continued to decrease three years after the deployment of LLINs. PMID:24892677

  15. Comparison of the Insecticidal Characteristics of Commercially Available Plant Essential Oils Against Aedes aegypti and Anopheles gambiae (Diptera: Culicidae).

    PubMed

    Norris, Edmund J; Gross, Aaron D; Dunphy, Brendan M; Bessette, Steven; Bartholomay, Lyric; Coats, Joel R

    2015-09-01

    Aedes aegypti and Anopheles gambiae are two mosquito species that represent significant threats to global public health as vectors of Dengue virus and malaria parasites, respectively. Although mosquito populations have been effectively controlled through the use of synthetic insecticides, the emergence of widespread insecticide-resistance in wild mosquito populations is a strong motivation to explore new insecticidal chemistries. For these studies, Ae. aegypti and An. gambiae were treated with commercially available plant essential oils via topical application. The relative toxicity of each essential oil was determined, as measured by the 24-h LD(50) and percentage knockdown at 1 h, as compared with a variety of synthetic pyrethroids. For Ae. aegypti, the most toxic essential oil (patchouli oil) was ∼1,700-times less toxic than the least toxic synthetic pyrethroid, bifenthrin. For An. gambiae, the most toxic essential oil (patchouli oil) was ∼685-times less toxic than the least toxic synthetic pyrethroid. A wide variety of toxicities were observed among the essential oils screened. Also, plant essential oils were analyzed via gas chromatography/mass spectrometry (GC/MS) to identify the major components in each of the samples screened in this study. While the toxicities of these plant essential oils were demonstrated to be lower than those of the synthetic pyrethroids tested, the large amount of GC/MS data and bioactivity data for each essential oil presented in this study will serve as a valuable resource for future studies exploring the insecticidal quality of plant essential oils. PMID:26336230

  16. Coverage and Timing of Children's Vaccination: An Evaluation of the Expanded Programme on Immunisation in The Gambia

    PubMed Central

    Scott, Susana; Odutola, Aderonke; Mackenzie, Grant; Fulford, Tony; Afolabi, Muhammed O.; Jallow, Yamundow Lowe; Jasseh, Momodou; Jeffries, David; Dondeh, Bai Lamin; Howie, Stephen R. C.; D'Alessandro, Umberto

    2014-01-01

    Objective To evaluate the coverage and timeliness of the Expanded Programme on Immunisation (EPI) in The Gambia. Methods Vaccination data were obtained between January 2005 and December 2012 from the Farafenni Health and Demographic Surveillance System (FHDSS), the Basse Health and Demographic Surveillance System (BHDSS), the Kiang West Demographic surveillance system (KWDSS), a cluster survey in the more urban Western Health Region (WR) and a cross sectional study in four clinics in the semi-urban Greater Banjul area of WR. Kaplan-Meier survival function was used to estimate the proportion vaccinated by age and to assess timeliness to vaccination. Findings BCG vaccine uptake was over 95% in all regions. Coverage of DPT1 ranged from 93.2% in BHDSS to 99.8% in the WR. Coverage decreased with increasing number of DPT doses; DPT3 coverage ranged from 81.7% in BHDSS to 99.0% in WR. Measles vaccination coverage ranged from 83.3% in BHDSS to 97.0% in WR. DPT4 booster coverage was low and ranged from 43.9% in the WR to 82.8% in KWDSS. Across all regions, delaying on previous vaccinations increased the likelihood of being delayed for the subsequent vaccination. Conclusions The Gambia health system achieves high vaccine coverage in the first year of life. However, there continues to be a delay to vaccination which may impact on the introduction of new vaccines. Examples of effectively functioning EPI programmes such as The Gambia one may well be important models for other low income countries struggling to achieve high routine vaccination coverage. PMID:25232830

  17. Some strains of Plasmodium falciparum, a human malaria parasite, evade the complement-like system of Anopheles gambiae mosquitoes.

    PubMed

    Molina-Cruz, Alvaro; DeJong, Randall J; Ortega, Corrie; Haile, Ashley; Abban, Ekua; Rodrigues, Janneth; Jaramillo-Gutierrez, Giovanna; Barillas-Mury, Carolina

    2012-07-10

    Plasmodium falciparum lines differ in their ability to infect mosquitoes. The Anopheles gambiae L3-5 refractory (R) line melanizes most Plasmodium species, including the Brazilian P. falciparum 7G8 line, but it is highly susceptible to some African P. falciparum strains such as 3D7, NF54, and GB4. We investigated whether these lines differ in their ability to evade the mosquito immune system. Silencing key components of the mosquito complement-like system [thioester-containing protein 1 (TEP1), leucine-rich repeat protein 1, and Anopheles Plasmodium-responsive leucine-rich repeat protein 1] prevented melanization of 7G8 parasites, reverting the refractory phenotype. In contrast, it had no effect on the intensity of infection with NF54, suggesting that this line is able to evade TEP1-mediated lysis. When R females were coinfected with a line that is melanized (7G8) and a line that survives (3D7), the coinfection resulted in mixed infections with both live and encapsulated parasites on individual midguts. This finding shows that survival of individual parasites is parasite-specific and not systemic in nature, because parasites can evade TEP1-mediated lysis even when other parasites are melanized in the same midgut. When females from an extensive genetic cross between R and susceptible A. gambiae (G3) mosquitoes were infected with P. berghei, encapsulation was strongly correlated with the TEP1-R1 allele. However, P. falciparum 7G8 parasites were no longer encapsulated by females from this cross, indicating that the TEP1-R1 allele is not sufficient to melanize this line. Evasion of the A. gambiae immune system by P. falciparum may be the result of parasite adaptation to sympatric mosquito vectors and may be an important factor driving malaria transmission. PMID:22623529

  18. A molecular phylogeny of the Dactylogyridae sensu Kritsky & Boeger (1989) (Monogenea) based on the D1-D3 domains of large subunit rDNA.

    PubMed

    Simková, A; Matejusová, I; Cunningham, C O

    2006-07-01

    Phylogenetic analyses based on the partial large subunit rDNA (LSU) sequences of polyonchoinean monogeneans belonging to the Dactylogyridea and Monocotylidea were generated to investigate relationships among various subfamilies of the Dactylogyridae sensu Kritsky & Boege