RESUMEN
Sand flies (Diptera: Psychodidae: Phlebotominae) are blood-feeding insects that transmit the protozoan parasites Leishmania spp. and various arboviruses. The Balkan region, including the Republic of Kosovo, harbours a diverse sand fly fauna. Vector species of Leishmania infantum as well as phleboviruses are endemic; however, recent data are scarce. We performed a cross-sectional study to update the current sand fly distribution in Kosovo and assess biological as well as environmental factors associated with sand fly presence. CDC light trapping was conducted at 46 locations in 2022 and 2023, specifically targeting understudied regions in Kosovo. Individual morphological species identification was supported by molecular barcoding. The occurrence data of sand flies was used to create distribution maps and perform environmental analyses, taking elevation, wind speed and climate-related factors into account. In addition, PCR-based blood meal analysis and pathogen screening were conducted. Overall, 303 specimens of six sand fly species were trapped, predominated by Phlebotomus neglectus (97%). Barcodes from eight of nine known endemic sand fly species were obtained. Combining our data with previous surveys, we mapped the currently known sand fly distribution based on more than 4000 specimens at 177 data points, identifying Ph. neglectus and Ph. perfiliewi as the predominant species. Environmental analyses depicted two geographical groups of sand flies in Kosovo, with notable differences between the species. In total, 223 blood meals of five sand fly species were analysed. Of seven identified host species, the predominant blood meal source was observed to be cattle, but the DNA of dogs and humans, among others, was also detected. This study assessed biological as well as ecological factors of sand fly occurrence, which should help better understand and evaluate potential hot spots of disease transmission in Kosovo.
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Distribución Animal , Insectos Vectores , Phlebotomus , Animales , Kosovo , Insectos Vectores/fisiología , Insectos Vectores/parasitología , Estudios Transversales , Phlebotomus/clasificación , Phlebotomus/fisiología , Phlebotomus/parasitología , Femenino , Psychodidae/fisiología , Psychodidae/parasitología , Masculino , Perros , Leishmania infantum/fisiologíaRESUMEN
BACKGROUND OBJECTIVES: The distribution of sandflies is influenced by several climatic factors, like winter temperature limits, summer humidity, and drought. Only a few studies were performed to search for the connection between the physiological tolerance of sandflies and the result of the Climate Envelope Models projected distribution borders. METHODS: It was studied how the depth of rodent burrows could determine the occurrence of five European Phlebotomus species based on their known physiological cold tolerances. RESULTS: The modelled distributions based on the monthly minimum temperatures showed notable differences by soil depth and species. The observed and modelled European distribution areas of sandflies according to - 20 cm soil depth showed good coincidence with the observed occurrences of Phlebotomus neglectus , Ph. papatasi , and Ph. perfiliewi in East-Central, Southeast, and East Europe. Also, a good coincidence was found in the case of the modelled and observed occurrences of Phlebotomus perniciosus in Western Europe. INTERPRETATION CONCLUSION: It can be concluded that in their north-eastern distribution borders, sandflies can overwinter in rabbit and rodent burrows at depths of - 20 cm below the surface. The physical cold tolerance of Ph. ariasi could be underestimated. In more than - 50 cm of depth, the stable and continuously cold environment of the shelters (mean temperature less than 10°C) could inhibit the post-winter diapause activation of sandflies in the northern regions.
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Frío , Phlebotomus , Animales , Phlebotomus/fisiología , Europa (Continente) , Distribución Animal , Estaciones del Año , Insectos Vectores/fisiología , Roedores/fisiología , ConejosRESUMEN
Cutaneous leishmaniasis is a parasitic and neglected tropical disease transmitted by the bites of sandflies. The emergence of cutaneous leishmaniasis in areas of war, conflict, political instability, and climate change has prompted efforts to develop a preventive vaccine. One vaccine candidate antigen is PpSP15, a 15 kDa salivary antigen from the sandfly Phlebotomus papatasi that facilitates the infection of the Leishmania parasite and has been shown to induce parasite-specific cell-mediated immunity. Previously, we developed a fermentation process for producing recombinant PpSP15 in Pichia pastoris and a two-chromatographic-step purification process at 100 mL scale. Here we expand the process design to the 10 L scale and examine its reproducibility by performing three identical process runs, an essential transition step towards technology transfer for pilot manufacture. The process was able to reproducibly recover 81% of PpSP15 recombinant protein with a yield of 0.75 g/L of fermentation supernatant, a purity level of 97% and with low variance among runs. Additionally, a freeze-thaw stability study indicated that the PpSP15 recombinant protein remains stable after undergoing three freeze-thaw cycles, and an accelerated stability study confirmed its stability at 37 °C for at least one month. A research cell bank for the expression of PpSP15 was generated and fully characterized. Collectively, the cell bank and the production process are ready for technology transfer for future cGMP pilot manufacturing.
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Proteínas de Insectos/inmunología , Leishmania/inmunología , Vacunas contra la Leishmaniasis/inmunología , Phlebotomus/química , Proteínas y Péptidos Salivales/inmunología , Animales , Clonación Molecular , Femenino , Fermentación , Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Humanos , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Leishmania/química , Vacunas contra la Leishmaniasis/genética , Vacunas contra la Leishmaniasis/metabolismo , Leishmaniasis Cutánea/prevención & control , Peso Molecular , Phlebotomus/fisiología , Estabilidad Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Proteínas y Péptidos Salivales/genética , Proteínas y Péptidos Salivales/metabolismoRESUMEN
Genus and species of phlebotomine sand flies have been recorded and described in caves in Brazil, but no study has provided the food source used by sand flies in these environments. Herein, we identified the blood source used by sand fly species in caves located at "Quadrilátero Ferrífero" (QF), Minas Gerais state. Specimens were manually collected near or on anurans inside ferruginous caves in Serra do Gandarela National Park and Serra do Rola Moça State Park. Males and females were placed in vials with 70% alcohol and stored at -10°C. Females engorged, after specific identification, had DNA extracted and followed for PCR amplification using specific primers. Sequencing was analyzed in the GenBank and Barcode of Life. A total of 198 specimens were collected (107 females and 91 males), all of them belonging to species Sciopemyia aff. microps (88.89%), Sciopemyia sordellii (10.61%), or Martinsmyia oliveirai (0.50%). When it comes to the females, 89 were S. aff. microps and 18 S. sordellii. Nineteen engorged females of S. aff. microps were analyzed and most of them (n=18) presented blood from Bokermannohyla martinsi and one contained blood from Scinax fuscovarius. The blood present in engorged females of S. sordellii (n=4) was from B. martinsi. Sciopemyia genus specimens are commonly found in collections carried out inside natural caves, but this was the first study to prove that females of this genus feed on cold-blooded animals in nature. HIGHLIGHTS: ⢠Here we proved that sand flies feed in cold-blooded animals in in Brazilian caves. ⢠Females of the Sciopemyia genus were for the first time found feeding in natural habitats. ⢠Anurans of the family Hylidae were identified as source by molecular analyzes. ⢠Insect bloodmeal identification can help assessing the fauna in several biomes. ⢠This is the first record of S. aff. microps in caves of Brazil.
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Anuros/parasitología , Phlebotomus/clasificación , Phlebotomus/fisiología , Animales , Brasil , ADN/genética , Conducta Alimentaria , Femenino , Alimentos , Masculino , Parques Recreativos , Reacción en Cadena de la PolimerasaRESUMEN
Phlebotomus neglectus is one of the most important vectors of visceral leishmaniasis in Southeast Europe and Asia Minor. It was aimed to study the impact of climate change on the seasonality and the range of the species for 2014-2060. In the inland areas of Asia Minor, the Balkan Peninsula and the Carpathian Basin the elongation of the activity season will reach or exceed the two months in the middle of the 21st century compared to the end of the 20th century. The most affected regions are the middle elevations of the mountainous regions and the plains of the northern distribution areas. In some areas of the southern distribution border, the season is expected to shorten. In the Apennine Peninsula, mainly the mountainous areas could be impacted notably by climate change. The results indicate the potential spread of leishmaniasis in Southeast Europe due to the increasing environmental suitability of the region.
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Cambio Climático , Insectos Vectores/fisiología , Leishmaniasis Visceral/transmisión , Phlebotomus/fisiología , Animales , Geografía , Región Mediterránea , Modelos Teóricos , Estaciones del AñoRESUMEN
Molecular studies indicate that Phlebotomine sandflies (Diptera: Psychodidae) blood feed on many vertebrate species, of which only a few are proven parasite reservoirs. Investigating sandfly vector feeding preferences is therefore important and requires taking into account the availability and accessibility of host species. In terms of the latter, it is necessary to consider the metabolic cost to the insect of reaching the host and moving on to a suitable breeding site. The present study used statistical modelling to compare the feeding patterns of Phlebotomus perniciosus (n = 150), Phlebotomus papatasi (n = 35) and Phlebotomus ariasi (n = 7) on each of an average of 30 host species in a wildlife park in Murcia, Spain. Sandfly feeding movement costs were estimated as a function of the distance and altitude gradients saved by the insect, assuming that they displayed 'site fidelity'. Most (87%) engorged females were caught <100 m from the host on which they had fed. Although the percentage of bloodmeals was highest on fallow deer (Dama dama) (30%) and red deer (Cervus elaphus) (26%), the predicted feeding probability after considering movement cost was highest for red deer and common eland (Taurotragus oryx), and positively associated with host census. These results suggest that, under similar circumstances, sandflies prefer to feed on some host species more than on others.
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Insectos Vectores/fisiología , Leishmania/fisiología , Phlebotomus/fisiología , Animales , Antílopes , Ciervos , Conducta Alimentaria , Movimiento , España , Especificidad de la EspecieRESUMEN
Understanding how arthropod vectors acquire their bacteria is essential for implementation of paratransgenic and RNAi strategies using genetically modified bacteria to control vector-borne diseases. In this study, a genetically marked Serratia AS1 strain expressing the mCherry fluorescent protein (mCherry-Serratia) was used to test various acquisition routes in six arthropod vectors including Anopheles stephensi, Culex pipiens, Cx. quinquefaciatus, Cx. theileri, Phlebotomus papatasi, and Hyalomma dromedarii. Depending on the species, the bacteria were delivered to (i) mosquito larval breeding water, (ii) host skin, (iii) sugar bait, and (iv) males (paratransgenic). The arthropods were screened for the bacteria in their guts or other tissues. All the hematophagous arthropods were able to take the bacteria from the skin of their hosts while taking blood meal. The mosquitoes were able to take up the bacteria from the water at larval stages and to transfer them transstadially to adults and finally to transfer them to the water they laid eggs in. The mosquitoes were also able to acquire the bacteria from male sperm. The level of bacterial acquisition was influenced by blood feeding time and strategies (pool or vessel feeding), dipping in water and resting time of newly emerged adult mosquitoes, and the disseminated tissue/organ. Transstadial, vertical, and venereal bacterial acquisition would increase the sustainability of the modified bacteria in vector populations and decrease the need for supplementary release experiments whereas release of paratransgenic males that do not bite has fewer ethical issues. Furthermore, this study is required to determine if the modified bacteria can be introduced to arthropods in the same routes in nature.
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Vectores Artrópodos/microbiología , Culicidae/microbiología , Ixodidae/microbiología , Control Biológico de Vectores/métodos , Phlebotomus/microbiología , Interferencia de ARN , Serratia/genética , Animales , Vectores Artrópodos/fisiología , Culicidae/fisiología , Femenino , Ixodidae/fisiología , Larva/microbiología , Larva/fisiología , Masculino , Control Biológico de Vectores/instrumentación , Phlebotomus/fisiología , Serratia/fisiologíaRESUMEN
BACKGROUND: Visceral Leishmaniasis (VL) is caused by a protozoan parasite Leishmania donovani that is transmitted to humans by an infected female sandfly, Phlebotomus argentipes. VL is common in the Indian sub-continent including Nepal and efforts for its elimination are ongoing. However, expansion of disease towards the higher altitude areas, previously considered as VL free in Nepal, may impact the ability to achieve the elimination target by 2020. METHODS: This was an exploratory study, where VL suspected patients living exclusively in the non-program districts of Nepal and presenting with fever > 2 weeks and splenomegaly was included. The patients' blood samples were collected, and DNA was extracted. DNA was subjected to PCR amplification and subsequent sequencing. Additionally, past 10 years data of VL cases from the national databases were analysed to see the trends of the disease in program and non program districts. RESULTS: Analysis of the past 10 years data revealed that trend of VL cases significantly decreased in the program districts (p = 0.001) while it increased in the non-program districts (p = 0.002). The national trend for overall incidence of VL also significantly decreased over this time period. Limited number of patients' samples (n = 14) were subjected to molecular investigation, and four patients were found to be positive for Leishmania species by PCR. Interestingly, these cases in non-program districts were indeed also L. donovoni complex. All four patients were male with age ranges from 10 to 68 years. GenBank BLAST of the obtained DNA sequences confirmed identified specimens as L. donovani complex. We identified additional VL cases from non-program districts (including the high lands) of Nepal, indicating that the infection could be an emerging threat for the non-program areas of Nepal. CONCLUSION: The demonstration of VL cases in areas initially considered non-endemic has raised concern about on-going transmission in those regions and may trigger subsequent government plan and action to include those areas in the elimination program. Thus, the government should consider revising the disease control programs to accommodate non-program districts for achieving the VL elimination goal set for 2020.
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Leishmania donovani/aislamiento & purificación , Leishmaniasis Visceral/parasitología , Adolescente , Adulto , Anciano , Animales , Niño , Humanos , Incidencia , Leishmania donovani/clasificación , Leishmania donovani/genética , Leishmaniasis Visceral/epidemiología , Leishmaniasis Visceral/prevención & control , Leishmaniasis Visceral/transmisión , Masculino , Persona de Mediana Edad , Nepal/epidemiología , Phlebotomus/parasitología , Phlebotomus/fisiología , Reacción en Cadena de la Polimerasa , Adulto JovenRESUMEN
The spatial and temporal distribution of Phlebotomus perniciosus (Diptera: Psychodidae) (Newstead, 1911), the sand fly vector of pathogens of public and animal health importance, was investigated in a high sand fly density rural area in Spain using light-attraction and sticky-interception traps. Traps were placed inside animal buildings and outside at increasing distance from animals. A total of 8506 sand flies were collected, 87% with light traps. Species frequency differed between trap types. The abundance of P. perniciosus decreased exponentially with increasing distance to animals and, while females were most common in the animal enclosure, males predominated in adjoining storage places. Increasing CO2 concentration had an additional positive effect on female abundance only. Both male and female density increased with rising temperature, and there was some indication that females were more active than males at higher relative humidity. The study confirms that P. perniciosus aggregates around animal premises, although male and female distributions differ and should be analysed separately to account for biological and behavioural differences. This provides further evidence that light traps offer an accurate estimation of the relative spatial and temporal abundance of P. perniciosus, conferring an added value for the study of this species and the risk of pathogen transmission.
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Distribución Animal , Vivienda para Animales , Phlebotomus/fisiología , Animales , Femenino , Masculino , Estaciones del Año , España , Análisis EspacialRESUMEN
Phlebotomine sandflies (Diptera: Phlebotomidae) are vectors of the zoonotic disease leishmaniasis. To better understand the distribution of phlebotomine sandflies in order to facilitate control of leishmaniasis transmission, the present study explored the impacts of climate and landscape on local abundances of Phlebotomus chinensis in northwestern mainland China. Identification records were used to create a geodatabase for the locations at which P. chinensis had been collected in the region, and a regional-scale map was developed to show the distribution of P. chinensis. Location data and data on environmental factors during the years in which the samples were collected were incorporated, and a presence-only modelling method was used to evaluate the species' habitat preferences and to predict its potential distribution in northwestern mainland China. Jackknife analysis revealed that several meteorological variables, including maximum temperature in the warmest quarter, precipitation in the driest month, daily average temperature and daily precipitation, significantly affected the presence of this species. Moreover, the presence of P. chinensis was significantly associated with grassland and shrubland. Probability distributions using maximum entropy were used to map the distribution ranges of P. chinensis based on suitable habitats in northwestern mainland China. The models generated can be used to develop detailed strategies for the prevention and control of leishmaniasis.
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Distribución Animal , Clima , Insectos Vectores/fisiología , Leishmania/fisiología , Phlebotomus/fisiología , Animales , China , GeografíaRESUMEN
Programmes for the control of phlebotomine sandflies (Diptera: Psychodidae), the vectors of leishmaniases, mainly target adults because larval breeding sites are generally unknown or inaccessible. To determine how blood-questing sandfly females enter homes and to develop means for their control, an experimental house (EH) was constructed in a village endemic for cutaneous leishmaniasis. Initially, carbon dioxide (CO2 )-baited suction traps were installed inside the EH to attract and capture sandflies. For other experiments, the windows of the EH were fitted with CO2 -baited window entrance traps (WETs) that allow each window to be considered as a separate unit. The majority of captures inside the EH and in WETs consisted of Phlebotomus sergenti, a species that enters inhabited houses relatively infrequently. Analyses of collections in WETs and in sticky traps on external walls showed that sandflies entered windows having landed previously on the wall below or either side of the window. Shelves constructed below windows significantly reduced the numbers of sandflies that entered both the EH and inhabited houses. The lining of internal walls with insecticide-impregnated fabric significantly increased mortality rates of sandflies captured inside the EH. To reduce the biting burden imposed by phlebotomine sandflies, several control measures must be integrated and sustained.
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Vivienda , Control de Insectos , Insecticidas , Phlebotomus , Animales , Conducta Alimentaria , Femenino , Control de Insectos/métodos , Israel , Medio Oriente , Phlebotomus/fisiologíaRESUMEN
The frequency of sandfly-host contacts can be measured by host antibody levels against sandfly salivary proteins. Recombinant salivary proteins are suggested to represent a valid replacement for salivary gland homogenate (SGH); however, it is necessary to prove that such antigens are recognized by antibodies against various populations of the same species. Phlebotomus perniciosus (Diptera: Psychodidae) is the main vector of Leishmania infantum (Trypanosomatida: Trypanosomatidae) in southwest Europe and is widespread from Portugal to Italy. In this study, sera were sampled from naturally exposed dogs from distant regions, including Campania (southern Italy), Umbria (central Italy) and the metropolitan Lisbon region (Portugal), where P. perniciosus is the unique or principal vector species. Sera were screened for anti-P. perniciosus antibodies using SGH and 43-kDa yellow-related recombinant protein (rSP03B). A robust correlation between antibodies recognizing SGH and rSP03B was detected in all regions, suggesting substantial antigenic cross-reactivity among different P. perniciosus populations. No significant differences in this relationship were detected between regions. Moreover, rSP03B and the native yellow-related protein were shown to share similar antigenic epitopes, as canine immunoglobulin G (IgG) binding to the native protein was inhibited by pre-incubation with the recombinant form. These findings suggest that rSP03B should be regarded as a universal marker of sandfly exposure throughout the geographical distribution of P. perniciosus.
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Enfermedades de los Perros/epidemiología , Mordeduras y Picaduras de Insectos/epidemiología , Proteínas de Insectos/análisis , Phlebotomus/fisiología , Proteínas y Péptidos Salivales/análisis , Animales , Antígenos/análisis , Enfermedades de los Perros/etiología , Perros , Mordeduras y Picaduras de Insectos/etiología , Insectos Vectores/parasitología , Insectos Vectores/fisiología , Italia/epidemiología , Leishmania infantum/fisiología , Leishmaniasis/parasitología , Leishmaniasis/veterinaria , Phlebotomus/parasitología , Portugal/epidemiología , Proteínas Recombinantes/análisisRESUMEN
BACKGROUND & OBJECTIVES: Phlebotomus papatasi is the main vector of the zoonotic cutaneous leishmaniasis (ZCL) in Qom Province and many other provinces of Iran. Attractive toxic sugar baits (ATSB) treated barrier fence is one of the new methods for controlling the vectors such as sandflies. The present study was designed to evaluate the residual activity of ATSB-treated barrier fence that was used in control of P. papatasi. METHODS: Following the selection of villages in Markazi district of Qom Province, central Iran during 2015 for ATSB and ASB (bait containing no active ingredient) methods; barrier fences on the ground in front of the rodent's colony were installed. A total of four conical tubes were installed and fixed on surfaces of treated barrier net of dimension 25 Χ 25 cm at biweekly interval. In each conical tube, 10 sand flies were released and after 3 min of exposure they were transferred to sterile cups. After 24 h, the obtained results were recorded according to the survival and mortality rate of sandflies. These tests were carried out five days after the installation of barrier fences, and repeated every 15 days until the mortality rate decreased to 60-65%. RESULTS: The bioassay tests results showed that the mortality rate of P. papatasi on ATSB-treated barrier fence for 5, 15, 30 and 45 days after spraying was 100, 95.83, 88.18 and 66.67% respectively, which decreased to 50.83% after 60 days. INTERPRETATION & CONCLUSION: Persistence and residual activity of the active ingredient of the bait in the hot and dry climatic conditions of Qom Province remained significantly effective for at most 45 days, which subsequently decreased at a high rate. Hence, every 45 days barrier fences need to be impregnated with ATSB bait. The method also appeared cost-effective and could be practical in implementation of vector control programmes against ZCL.
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Bioensayo , Control de Insectos/métodos , Insecticidas/farmacología , Feromonas/farmacología , Phlebotomus/efectos de los fármacos , Phlebotomus/fisiología , Animales , Carbohidratos/farmacología , Clima , Femenino , Irán , MasculinoRESUMEN
Crimea was known to be a mosquito-borne fever (pappataci fever) endemic area in the past. There is information on sporadic cases of visceral leishmaniasis (VL), the vectors for which are also mosquitoes. This disease was registered in Crimea in both the 20h century and the early 21st century. The data available in the literature on the mosquitoes in Crimea, which were published mainly in the first half of the 20th century, have been analyzed. Based on the classification of these insects, which has been proposed by M.M. Artemyev, the authors have established that there are 8 mosquito species: P.papatasi, P.alexandri, P.similis, P.neglectus, P.perfiliewi, P.balcanicus, P.longiductus, and S.dentata in Crimea. There is evidence on the landscape and biotopic association of individual species and on their environmental features.
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Ecosistema , Phlebotomus/clasificación , Phlebotomus/fisiología , Animales , Federación de RusiaRESUMEN
The distribution of phlebotomine sand flies is widely reported to be changing in Europe. This can be attributed to either the discovery of sand flies in areas where they were previously overlooked (generally following an outbreak of leishmaniasis or other sand fly-related disease) or to true expansion of their range as a result of climatic or environmental changes. Routine surveillance for phlebotomines in Europe is localized, and often one of the challenges for entomologists working in non-leishmaniasis endemic countries is the lack of knowledge on how to conduct, plan and execute sampling for phlebotomines, or how to adapt on-going sampling strategies for other haematophagous diptera. This review brings together published and unpublished expert knowledge on sampling strategies for European phlebotomines of public health concern in order to provide practical advice on: how to conduct surveys; the collection and interpretation of field data; suitable techniques for the preservation of specimens obtained by different sampling methods; molecular techniques used for species identification; and the pathogens associated with sand flies and their detection methods.
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Insectos Vectores/fisiología , Phlebotomus/fisiología , Animales , Código de Barras del ADN Taxonómico , Europa (Continente) , Insectos Vectores/microbiología , Insectos Vectores/parasitología , Phlebotomus/microbiología , Phlebotomus/parasitología , Densidad de Población , Dinámica Poblacional , Vigilancia de la Población/métodosRESUMEN
Animal models are often used to study hematophagous insect feeding behavior and evaluate products such as topical repellents. However, when these models are used the study animals often experience significant drops in core body temperature because of the effects of anesthesia. This study used a guinea pig model to investigate whether maintaining a normothermic core body temperature during anesthesia influenced the rate of Anopheles stephensi and Phlebotomus papatasi blood feeding. Experiments were conducted with anesthetized animals that had their body temperatures either maintained with a warming device or were allowed to drop naturally. Results showed that when guinea pigs were actively warmed by a heating device, An. stephensi feeding behavior was similar at the beginning and end of anesthesia. However, when a warming device was not used, fewer An. stephensi took a blood meal after the animals' temperatures had dropped. Phlebotomus papatasi were not as sensitive to changes in temperature and feeding rates were similar whether a warming device was used or not. These results are discussed and it is recommended that warming devices are used when conducting feeding experiments with insects sensitive to changes in host body temperature, such as An. stephensi.
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Anestesia General , Anopheles/fisiología , Temperatura Corporal , Conducta Alimentaria/fisiología , Calor , Phlebotomus/fisiología , Animales , CobayasRESUMEN
In sandflies, the absence of the peritrophic matrix (PM) affects the rate of blood digestion. Also, the kinetics of PM secretion varies according to species. We previously characterised PpChit1, a midgut-specific chitinase secreted in Phlebotomus papatasi (PPIS) that is involved in the maturation of the PM and showed that antibodies against PpChit1 reduce the chitinolytic activity in the midgut of several sandfly species. Here, sandflies were fed on red blood cells reconstituted with naïve or anti-PpChit1 sera and assessed for fitness parameters that included blood digestion, oviposition onset, number of eggs laid, egg bouts, average number of eggs per bout and survival. In PPIS, anti-PpChit1 led to a one-day delay in the onset of egg laying, with flies surviving three days longer compared to the control group. Anti-PpChit1 also had a negative effect on overall ability of flies to lay eggs, as several gravid females from all three species were unable to lay any eggs despite having lived longer than control flies. Whereas the longer survival might be associated with improved haeme scavenging ability by the PM, the inability of females to lay eggs is possibly linked to changes in PM permeability affecting nutrient absorption.
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Quitinasas/inmunología , Sueros Inmunes , Factores Inmunológicos/farmacología , Proteínas de Insectos/efectos de los fármacos , Insectos Vectores/efectos de los fármacos , Phlebotomus/efectos de los fármacos , Animales , Quitinasas/metabolismo , ADN Complementario , Digestión/efectos de los fármacos , Conducta Alimentaria , Femenino , Absorción Gastrointestinal/efectos de los fármacos , Hemoglobinas/metabolismo , Sueros Inmunes/inmunología , Proteínas de Insectos/metabolismo , Insectos Vectores/fisiología , Masculino , Ratones Endogámicos BALB C , Control de Mosquitos/métodos , Oviposición/efectos de los fármacos , Phlebotomus/fisiología , PlásmidosRESUMEN
Although being typical Mediterranean faunal elements, phlebotomine sandflies have also been recorded in central Europe for several countries including Germany, where two species, Phlebotomus mascittii and Phlebotomus perniciosus, occur. In Europe, P. mascittii is the northernmostly distributed phlebotomine species. While P. perniciosus is a proven vector of leishmaniasis as well as various sandfly fever causing phleboviruses, the situation for P. mascittii is different. For this species, vector competence could not be proven yet, but is strongly suspected. During an entomological survey in July 2013, one female sandfly was caught in Giessen in the German state of Hesse. Adjacent to the collection site, different potential habitats could be found. Morphological examination of the cibarium, pharynx, and genitalia revealed the specimen as P. mascittii. This is the first reported occurrence for Hesse, and not only the northernmost documented occurrence for P. mascittii, but also of the whole subfamily in the Palearctic region. New records of proven or suspected vectors are of medical relevance because of potential Leishmania and/or Phlebovirus transmission and the awareness therefore in the public.
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Insectos Vectores/fisiología , Leishmania/fisiología , Leishmaniasis/transmisión , Phlebotomus/fisiología , Animales , Demografía , Femenino , Masculino , MatricariaRESUMEN
Phlebotomine sand flies are important vectors of medical and veterinary importance, transmitting pathogens, such as the Leishmania parasites, responsible for 700,000 to 1 million new cases of leishmaniasis every year. The vast majority of the current sand fly surveillance and control tools are tailored against the adult stages, due to the limited knowledge on the ecology of the larval stages. Since vector control is primarily an ecological problem, an in-depth understanding of the behavior of the target insect pests across all the different life stages of their development is required prior to the development of effective control strategies. It is well known that chemical cues play an important role in insect behavior. While there are numerous studies investigating the behavior of adult sand flies in response to chemical sources, there is currently no information available on the response of their larval stages. In this study, novel bioassays were constructed to investigate the effect of chemical cues (gustatory and olfactory) on the behavior of Phlebotomus papatasi (Scopoli) sand fly larvae. The larvae exhibited a clear food preference within a few hours of exposure in a 2-choice bioassay, while, also, demonstrated positive chemotaxis in response to volatile stimuli emitted from their preferred food source. Identification of the specific chemical compounds (or the combination thereof) eliciting attractance response to sand fly immature stages could lead to the development of innovative, and targeted (larval-specific) tools for the surveillance, and management of these important public health pests.
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Quimiotaxis , Larva , Phlebotomus , Animales , Phlebotomus/fisiología , Larva/crecimiento & desarrollo , Larva/fisiología , Prueba de Estudio Conceptual , Señales (Psicología) , FemeninoRESUMEN
BACKGROUND: Sand fly females require a blood meal to develop eggs. The size of the blood meal is crucial for fecundity and affects the dose of pathogens acquired by females when feeding on infected hosts or during experimental membrane-feeding. METHODS: Under standard laboratory conditions, we compared blood meal volumes taken by females of ten sand fly species from four genera: Phlebotomus, Lutzomyia, Migonomyia, and Sergentomyia. The amount of ingested blood was determined using a haemoglobin assay. Additionally, we weighed unfed sand flies to calculate the ratio between body weight and blood meal weight. RESULTS: The mean blood meal volume ingested by sand fly females ranged from 0.47 to 1.01 µl. Five species, Phlebotomus papatasi, P. duboscqi, Lutzomyia longipalpis, Sergentomyia minuta, and S. schwetzi, consumed about double the blood meal size compared to Migonomyia migonei. The mean body weight of females ranged from 0.183 mg in S. minuta to 0.369 mg in P. duboscqi. In males, the mean body weight ranged from 0.106 mg in M. migonei to 0.242 mg in P. duboscqi. Males were always lighter than females, with the male-to-female weight ratio ranging from 75% (in Phlebotomus argentipes) to 52% (in Phlebotomus tobbi). CONCLUSIONS: Females of most species took a blood meal 2.25-3.05 times their body weight. Notably, the relatively tiny females of P. argentipes consumed blood meals 3.34 times their body weight. The highest (Mbl/Mf) ratios were found in both Sergentomyia species studied; females of S. minuta and S. schwetzi took blood meals 4.5-5 times their body weight. This parameter is substantially higher than that reported for mosquitoes and biting midges.