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1.
Parasitol Res ; 119(4): 1177-1199, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32246259

RESUMO

A few data are related to the anthropophily of Malagasy Phlebotomine sandflies. Prior studies focussed mainly to inventories and description of new species. Our goal was to emphasize the anthropophily of Malagasy Phlebotomine sandflies. We worked in the Makira region, using two simultaneous methods: human landing catches (HLC) and CDC light traps. We collected sandflies in three rural communities adjacent to the Makira Natural Park. In each community, three different biotopes were sampled: within community settlements; at the edge of forest, typically in agricultural land; and within the forest. We collected 61 sandflies belonging to two new species presently described: Phlebotomus artemievi sp. nov. and Sergentomyia maroantsetraensis sp. nov. These sandflies were caught exclusively in the forest edge biotope. None were captured within communities or within forests. HLC provided 97% of the collected sandflies, corresponding to a human-biting rate of 15 females per human per night. CDC provided only two females. Ph. artemievi sp. nov. was predominantly captured by HLC and appears to be highly anthropophilic. Here, we update the behavioural ecology of sandflies and describe two new species. Further research is required to understand their vector competence and their ability to transmit arboviruses and other pathogens such as Leishmania.


Assuntos
Florestas , Phlebotomus , Psychodidae , Animais , Vetores de Doenças , Ecossistema , Feminino , Madagáscar , Masculino , Phlebotomus/classificação , Psychodidae/classificação
2.
Infect Dis Poverty ; 9(1): 30, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32183909

RESUMO

BACKGROUND: As of 2015 thousands of refugees are being hosted in temporary refugee camps in Greece. Displaced populations, travelling and living under poor conditions with limited access to healthcare are at a high risk of exposure to vector borne disease (VBD). This study sought to evaluate the risk for VBD transmission within refugee camps in Greece by analyzing the mosquito and sand fly populations present, in light of designing effective and efficient context specific vector and disease control programs. METHODS: A vector/pathogen surveillance network targeting mosquitoes and sand flies was deployed in four temporary refugee camps in Greece. Sample collections were conducted bi-weekly during June-September 2017 with the use of Centers for Disease Control (CDC) light traps and oviposition traps. Using conventional and molecular diagnostic tools we investigated the mosquito/sand fly species composition, population dynamics, pathogen infection rates, and insecticide resistance status in the major vector species. RESULTS: Important disease vectors including Anopheles sacharovi, Culex pipiens, Aedes albopictus and the Leishmania vectors Phlebotomus neglectus, P. perfiliewi and P. tobbi were recorded in the study refugee camps. No mosquito pathogens (Plasmodium parasites, flaviviruses) were detected in the analysed samples yet high sand fly Leishmania infection rates are reported. Culex pipiens mosquitoes displayed relatively high knock down resistance (kdr) mutation allelic frequencies (ranging from 41.0 to 63.3%) while kdr mutations were also detected in Ae. albopictus populations, but not in Anopheles and sand fly specimens. No diflubenzuron (DFB) mutations were detected in any of the mosquito species analysed. CONCLUSIONS: Important disease vectors and pathogens in vectors (Leishmania spp.) were recorded in the refugee camps indicating a situational risk factor for disease transmission. The Cx. pipiens and Ae. albopictus kdr mutation frequencies recorded pose a potential threat against the effectiveness of pyrethroid insecticides in these settings. In contrast, pyrethroids appear suitable for the control of Anopheles mosquitoes and sand flies and DFB for Cx. pipiens and Ae. albopictus larvicide applications. Targeted actions ensuring adequate living conditions and the establishment of integrated vector-borne disease surveillance programs in refugee settlements are essential for protecting refugee populations against VBDs.


Assuntos
Insetos Vetores/efeitos dos fármacos , Insetos Vetores/genética , Resistência a Inseticidas/genética , Leishmania , Controle de Mosquitos , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/genética , Dinâmica Populacional , Campos de Refugiados , Aedes/efeitos dos fármacos , Aedes/genética , Animais , Anopheles/efeitos dos fármacos , Anopheles/genética , Culex/efeitos dos fármacos , Culex/genética , Feminino , Grécia , Leishmania/genética , Leishmania/patogenicidade , Leishmaniose/epidemiologia , Phlebotomus/efeitos dos fármacos , Phlebotomus/genética , Psychodidae
3.
PLoS One ; 15(3): e0220268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155153

RESUMO

Caves are extreme and inhospitable environments that can harbor several species of vertebrate and invertebrate animals. Among these animals are phlebotomine sand flies, vectors of parasites of the genus Leishmania that cause leishmaniasis. This study aimed to evaluate the species composition of sand flies of four caves, a cave located at Moeda Sul (MS) and three at Parque Estadual Serra do Rola Moça (PESRM), in the region of the Quadrilátero Ferrífero in the state of Minas Gerais, southeastern Brazil. Sand flies were collected with automatic light traps. Non-Metric Multidimensional Scaling, using a dissimilarity matrix calculated with the Jaccard index, and Multivariate Permutation Analysis were used to evaluate sand fly species composition among entrance, interior, and the surrounding environments of each sampled cave and to infer biological mechanisms from patterns of distribution among these different cave environments. A total of 375 phlebotomine sand flies representing 14 species and six genera were collected. The most abundant species were Evandromyia tupynambai (54.7%), Brumptomyia troglodytes (25.6%), Evandromyia edwardsi (6.1%), Psathyromyia brasiliensis (4.8%) and Lutzomyia longipalpis (4.3%). Thirty individuals were collected at MS, 16 inside the cave and 14 from its surroundings. At PESRM, five individuals were collected from the surroundings of cave RM38, 190 individuals from cave RM39 (48 in the cave and 142 from its surroundings) and 150 individuals from cave RM40 (42 in the cave and 108 from its surroundings). The results revealed a rich sand fly fauna with similar species compositions among the entrance, interior, and surrounding environments of each sampled cave, suggesting that both caves and their surroundings are important for maintaining sand fly communities.


Assuntos
Cavernas , Psychodidae/fisiologia , Animais , Brasil , Geografia , Phlebotomus/fisiologia , Especificidade da Espécie
4.
PLoS Negl Trop Dis ; 14(3): e0007947, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32196501

RESUMO

BACKGROUND: Cutaneous leishmaniasis (CL) is a major public health concern in Ethiopia. However, knowledge about the complex zoonotic transmission cycle is limited, hampering implementation of control strategies. We explored the feeding behavior and activity of the vector (Phlebotomus pedifer) and studied the role of livestock in CL transmission in southwestern Ethiopia. METHODS: Blood meal origins of engorged sand flies were determined by sequencing host DNA. A host choice experiment was performed to assess the feeding preference of P. pedifer when humans and hyraxes are equally accessible. Ear and nose biopsies from livestock were screened for the presence of Leishmania parasites. Sand flies were captured indoor and outdoor with human landing catches and CDC light traps to determine at which time and where P. pedifer is mostly active. PRINCIPAL FINDINGS: A total of 180 P. pedifer sand flies were found to bite hosts of 12 genera. Humans were the predominant blood meal source indoors (65.9%, p < 0.001), while no significant differences were determined outdoors and in caves. In caves, hyraxes were represented in blood meals equally as humans (45.5% and 42.4%, respectively), but the host choice experiment revealed that sand flies have a significant preference for feeding on hyraxes (p = 0.009). Only a single goat nose biopsy from 412 animal samples was found with Leishmania RNA. We found that P. pedifer is predominantly endophagic (p = 0.003), but occurs both indoors and outdoors. A substantial number of sand flies was active in the early evening, which increased over time reaching its maximum around midnight. CONCLUSION: In contrast to earlier suggestions of exclusive zoonotic Leishmania transmission, we propose that there is also human-to-human transmission of CL in southwestern Ethiopia. Livestock does not play a role in CL transmission and combined indoor and outdoor vector control measures at night are required for efficient vector control.


Assuntos
Reservatórios de Doenças/parasitologia , Comportamento Alimentar , Leishmania/isolamento & purificação , Gado/parasitologia , Phlebotomus/fisiologia , Phlebotomus/parasitologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Transmissão de Doença Infecciosa , Etiópia , Feminino , Humanos , Leishmaniose Cutânea/transmissão , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
PLoS Negl Trop Dis ; 14(3): e0008077, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32214313

RESUMO

BACKGROUND: Phlebotomus (Larroussius) perniciosus and Canis familiaris are respectively the only confirmed vector and reservoir for the transmission of Leishmania (L.) infantum MON-1 in Tunisia. However, the vector and reservoir hosts of the two other zymodemes, MON-24 and MON-80, are still unknown. The aim of this study was to analyze the L. infantum life cycle in a Tunisian leishmaniasis focus. For this purpose, we have focused on: i) the detection, quantification and identification of Leishmania among this sand fly population, and ii) the analysis of the blood meal preferences of Larroussius (Lar.) subgenus sand flies to identify the potential reservoirs. METHODOLOGY AND FINDINGS: A total of 3,831 sand flies were collected in seven locations from the center of Tunisia affected by human visceral leishmaniasis. The collected sand flies belonged to two genus Phlebotomus (Ph.) (five species) and Sergentomyia (four species). From the collected 1,029 Lar. subgenus female sand flies, 8.26% was positive to Leishmania by ITS1 nested PCR. Three Leishmania spp. were identified: L. infantum 28% (24/85), L. killicki 13% (11/85), and L. major 22% (19/85). To identify the blood meal sources in Ph. Lar. subgenus sand flies, engorged females were analyzed by PCR-sequencing targeting the vertebrate cytochrome b gene. Among the 177 analyzed blood-fed females, 169 samples were positive. Sequencing results showed seven blood sources: cattle, human, sheep, chicken, goat, donkey, and turkey. In addition, mixed blood meals were detected in twelve cases. Leishmania DNA was found in 21 engorged females, with a wide range of blood meal sources: cattle, chicken, goat, chicken/cattle, chicken/sheep, chicken/turkey and human/cattle. The parasite load was quantified in fed and unfed infected sand flies using a real time PCR targeting kinetoplast DNA. The average parasite load was 1,174 parasites/reaction and 90 parasites/reaction in unfed and fed flies, respectively. CONCLUSION: Our results support the role of Ph. longicuspis, Ph. perfiliewi, and Ph. perniciosus in L. infantum transmission. Furthermore, these species could be involved in L. major and L. killicki life cycles. The combination of the parasite detection and the blood meal analysis in this study highlights the incrimination of the identified vertebrate in Leishmania transmission. In addition, we quantify for the first time the parasite load in naturally infected sand flies caught in Tunisia. These findings are relevant for a better understanding of L. infantum transmission cycle in the country. Further investigations and control measures are needed to manage L. infantum transmission and its spreading.


Assuntos
DNA/análise , Comportamento Alimentar , Conteúdo Gastrointestinal/química , Conteúdo Gastrointestinal/parasitologia , Especificidade de Hospedeiro , Leishmania infantum/isolamento & purificação , Phlebotomus/fisiologia , Animais , DNA/genética , Impressões Digitais de DNA , DNA Espaçador Ribossômico/genética , Transmissão de Doença Infecciosa , Feminino , Humanos , Leishmania infantum/genética , Masculino , Phlebotomus/parasitologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Tunísia
6.
PLoS Negl Trop Dis ; 14(2): e0008024, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069279

RESUMO

Cutaneous leishmaniasis is a disease caused by various Leishmania spp., which are transmitted by phlebotomine sand flies. Algeria is one of the most affected countries, with thousands of cutaneous leishmaniasis cases registered every year. From March to November of 2016 and 2017, sand flies were collected in 12 municipalities in Setif province, North-Eastern Algeria. Sand flies were identified and females were tested by PCR for detecting Leishmania DNA. Additionally, cutaneous leishmaniasis cases notified during the study period were analysed. Out of 1804 sand flies collected, 1737 were identified as belonging to seven species, with Phlebotomus perniciosus (76.2%), Ph. papatasi (16.7%) and Ph. sergenti (5.0%) being the most common species, representing together 97.9% of the collected specimens. The remaining specimens were identified as Sergentomyia minuta, Se. fallax, Ph. longicuspis and Ph. perfiliewi. The number of sand flies collected monthly was positively correlated with temperature. Out of 804 females tested, nine Ph. perniciosus (1.1%) scored positive for Leishmania infantum (n = 5), L. major (n = 3) and L. tropica (n = 1), respectively. During the study period, 34 cutaneous leishmaniasis cases were notified in Setif, of which 58.8% were patients residing in two urban and peri-urban municipalities and 41.2% in rural areas. The finding of Ph. perniciosus as the most abundant species in Setif suggests that this sand fly may be adapted to different biotopes in the North-East region of Algeria. The detection of different Leishmania spp. in Ph. perniciosus suggests a complex epidemiological picture of cutaneous leishmaniasis in Setif, with the involvement of different etiological agents and possibly with different reservoir hosts and vectors.


Assuntos
Leishmania/fisiologia , Leishmaniose Cutânea/epidemiologia , Phlebotomus/parasitologia , Argélia/epidemiologia , Animais , Interações Hospedeiro-Parasita , Humanos , Umidade , Leishmania/classificação , Leishmaniose Cutânea/parasitologia , Phlebotomus/classificação , Estações do Ano , Especificidade da Espécie , Temperatura
7.
Parasitol Res ; 119(3): 795-803, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31982928

RESUMO

A new species of Biskratrombium (Trombidiformes: Microtrombidiidae), B. persicumn. sp. is described and illustrated, from Fars province, southern Iran. Biskratrombium persicum larvae are ectoparasites of the adults of Phlebotomus (Paraphlebotomus) alexandri (Sinton, 1928), P. (Phlebotomus) papatasi (Scopoli, 1786) and Sergentomyia (Sergentomyia) mervynae (Pringle, 1953) (Diptera: Psychodidae). Fars province is considered as a significant focus of leishmaniasis, a disease which is mostly associated with rural areas; these areas offer favorable habitats to the phlebotomine sandflies due to limited sanitation. This study was performed to identify the natural enemies of sandflies (as leishmania disease vectors) in this region. In this research, B. persicum larvae were removed from their sandfly hosts collected from foci of leishmaniasis (e.g., sheep and goat keeping locations) using sticky traps. Also, the abundance of sandflies infested with the parasitic mite was calculated. Some morphological abnormalities in the species are noted and world parasitengone mites parasitizing phlebotomine sandflies are reviewed.


Assuntos
Insetos Vetores/parasitologia , Ácaros/fisiologia , Phlebotomus/parasitologia , Animais , Irã (Geográfico) , Larva/fisiologia , Leishmania , Leishmaniose/parasitologia , Leishmaniose/transmissão
8.
PLoS Negl Trop Dis ; 14(1): e0007939, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31899767

RESUMO

Cutaneous leishmaniasisis a vector-borne disease transmitted by Leishmania infected sand flies. PpSP15 is an immunogenic salivary protein from the sand fly Phlebotomus papatasi. Immunization with PpSP15 was shown to protect against Leishmania major infection. Lactococcus lactis is a safe non-pathogenic delivery system that can be used to express antigens in situ. Here, the codon-optimized Ppsp15-egfp gene was cloned in pNZ8121 vector downstream of the PrtP signal peptide that is responsible for expression and secretion of the protein on the cell wall. Expression of PpSP15-EGFP recombinant protein was monitored by immunofluorescence, flow cytometry and Western blot. Also, expression of protein in cell wall compartment was verified using whole cell ELISA, Western blot and TEM microscopy. BALB/c mice were immunized three times with recombinant L. lactis-PpSP15-EGFPcwa, and the immune responses were followed up, at short-term (ST, 2 weeks) and long-term (LT, 6 months) periods. BALB/c mice were challenged with L. major plus P. papatasi Salivary Gland Homogenate. Evaluation of footpad thickness and parasite burden showed a delay in the development of the disease and significantly decreased parasite numbers in PpSP15 vaccinated animals as compared to control group. In addition, immunized mice showed Th1 type immune responses. Importantly, immunization with L. lactis-PpSP15-EGFPcwa stimulated the long-term memory in mice which lasted for at least 6 months.


Assuntos
Lactococcus lactis/metabolismo , Leishmania major , Proteínas e Peptídeos Salivares/metabolismo , Animais , Feminino , Proteínas de Insetos/imunologia , Lactococcus lactis/genética , Leishmaniose Cutânea/transmissão , Camundongos Endogâmicos BALB C , Phlebotomus/genética , Proteínas Recombinantes/imunologia , Proteínas e Peptídeos Salivares/genética
9.
Parasitol Res ; 119(1): 63-73, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31813012

RESUMO

This study provides updated information on the distribution of the phlebotomine sand fly species and their genetic characterization in Sardinia, a Mediterranean island where leishmaniasis is endemic. From April to November 2017, sand flies were trapped in five different capture sites using sticky traps and light traps as collection methods, operated nearby sheep, poultry, cat, and dog shelters. Phlebotomine specimens (n = 513) collected were morphologically and molecularly identified as Phlebotomus perniciosus (249/513, 48.5%), Phlebotomus perfiliewi (236/513; 46%), and Sergentomyia minuta (28/513, 5.5%). Sand flies were collected from the second half of May to October confirming the well-defined seasonal activity, which peaks in August in Sardinia. Overall, correlation analyses indicated a significant positive association between the monthly number of sand flies collected and the mean temperature (r = 0.88, rho = 0.87, and tau = 0.69, P < 0.05), while there was non-significant, moderately negative correlation between the monthly number of sand flies collected and the monthly mean relative humidity and wind (r = - 0.22, rho = 0.02, and tau = 0.04, P > 0.05). This study provides the first data on the molecular characterization of phlebotomine sand flies in this region and confirms the presence of three sand fly species. Molecular results suggest that the morphological features used for analysis represent synapomorphic-derived characters which are shared among descendant taxa and the common ancestor.


Assuntos
Phlebotomus/classificação , Phlebotomus/genética , Animais , Gatos , Cães , Feminino , Insetos Vetores , Itália/epidemiologia , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Phlebotomus/parasitologia , Ovinos , Temperatura
10.
Pest Manag Sci ; 76(3): 961-966, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31471936

RESUMO

BACKGROUND: Phlebotomine sandfly (Diptera: Psychodidae) is best known for its role as the vector of the leishmaniasis. Leishmaniasis is a global disease, currently known to be affecting 88 countries and 12 million people worldwide. RESULTS: This study explored the impacts of climate factors and landscape on the local abundance of Phlebotomine sandfly in mainland China. A presence-only modelling method was used to evaluate this species' habitat preferences from environmental factors. Jackknife analysis revealed that several biologically meteorological variables, including the maximum temperature of the warmest quarter, the precipitation in the driest month, the daily average temperature and daily precipitation, would significantly affect the existence of this species. Moreover, the existence of Phlebotomine sandfly was significantly associated with grassland and forest. CONCLUSION: The results will improve scientific understanding of the risks of the spread of leishmaniasis over current infected areas and can be used to design more detailed surveillance programmes and more evidence-based control planning for Phlebotomine sandfly and leishmaniasis. © 2019 Society of Chemical Industry.


Assuntos
Leishmaniose , Phlebotomus , Animais , China , Insetos Vetores
11.
Acta Trop ; 201: 105220, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31618609

RESUMO

Mexico has great diversity of phlebotomine sand flies related to cases of leishmaniasis, yet few studies have dressed the molecular taxonomy of these sand fly species. The use of the cytochrome oxidase subunit 1 (COI) gene, as a DNA Barcode has facilitated the molecular identification of sand flies species worldwide. We use the DNA barcode as a useful tool for the identification of phlebotomine sand flies of the natural reserve Los Tuxtlas from Veracruz, México. A fragment of 536 bp of the COI gene was obtained from 36 individuals belonging to eight species of five genera (Dampfomyia, Lutzomyia, Psathyromyia, Psychodopygus and Brumptomyia) with coverage between 92-100%, and found similarities ranging from 93-98% with other New World phlebotomine sand flies. The NJ dendogram grouped sand flies into eight clusters according to identified species, supported by bootstrap of 97%-100%. In conclusion, all phlebotomine sand flies were correctly identified and agree with the morphological identification, also could separate genetics the isomorphic females of the genus Brumptomyia.


Assuntos
Código de Barras de DNA Taxonômico , Vetores de Doenças/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Leishmaniose/genética , Phlebotomus/classificação , Phlebotomus/genética , Animais , Brasil , Feminino , México
12.
Zootaxa ; 4688(3): zootaxa.4688.3.4, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31719438

RESUMO

Here we present an Android mobile application (app) for the identification of Brazilian phlebotomine sand fly species. The app, which is named LutzoDex™, relies on information included in a data source with morphological and morphometrical characters. This tool can present up to seven answer options to a question. Images of morphological structures can be referenced to make identification easier, and users can see a list of possible species based on the features they report. Maps are also used to determine the geographical distribution and whether the species is incriminated or suspected as a vector of Leishmania spp. in Brazil. The app is available free of charge in both English and Portuguese in the Google Play Store at https://play.google.com/store/apps/details?id=max.com.lutzodexhl=pt_BR.


Assuntos
Leishmania , Phlebotomus , Psychodidae , Animais , Brasil , Insetos Vetores
13.
Parasite ; 26: 63, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31687926

RESUMO

Twelve healthy dogs were included in this laboratory efficacy study. Six dogs were randomly allocated based on body weight to an untreated control group and six to an afoxolaner (NexGard®) treated group. In the treatment group, afoxolaner was administered orally on Day 0 in accordance with label instructions. On Days 1, 14 and 28, each dog was exposed to 60 unfed female and 10 male Phlebotomus perniciosus sandflies for 1 h. At the end of each exposure period, sandflies were counted and assessed for viability and feeding status. There was no statistical difference in mortality (0.0-5.4%), nor in feeding proportion (61.6-78%) between the control and the treated groups at all 1-h post-exposure assessments. After collection, live fed and unfed sandflies were kept for viability assessments at 48 and 72 h post-exposure. In the untreated control group, the average percentages of live, fed, female sandflies after exposure, on Days 1, 14 and 28, ranged from 51% to 74% at 48 h and from 46% to 57% at 72 h, demonstrating model robustness over the 28 days of the study. Significantly fewer live fed sandflies were recorded for the afoxolaner treated group (p < 0.01). The insecticidal efficacy was 100%, 95.9% and 75.2% at 48 h post Days 1, 14 and 28 exposures, respectively, and 100%, 100% and 86.3% at 72 h post Days 1, 14, and 28 exposures, respectively. A single administration of oral afoxolaner (NexGard®) to dogs significantly killed P. perniciosus sandflies 48 and 72 h after blood feeding for 1 month.


Assuntos
Doenças do Cão/tratamento farmacológico , Inseticidas/uso terapêutico , Isoxazóis/uso terapêutico , Naftalenos/uso terapêutico , Phlebotomus/efeitos dos fármacos , Infestações por Carrapato/veterinária , Administração Oral , Animais , Cães , Esquema de Medicação , Feminino , Masculino , Infestações por Carrapato/tratamento farmacológico
14.
PLoS Negl Trop Dis ; 13(11): e0007832, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31751334

RESUMO

BACKGROUND: Canine leishmaniasis (CanL) is a severe chronic disease caused by Leishmania infantum and transmitted by sand flies of which the main vector in the Western part of the Mediterranean basin is Phlebotomus perniciosus. Previously, an immunochromatographic test (ICT) was proposed to allow rapid evaluation of dog exposure to P. perniciosus. In the present study, we optimized the prototype and evaluated the detection accuracy of the ICT in field conditions. Possible cross-reactions with other hematophagous arthropods were also assessed. METHODOLOGY/PRINCIPAL FINDINGS: The ICT was optimized by expressing the rSP03B protein in a HEK293 cell line, which delivered an increased specificity (94.92%). The ICT showed an excellent reproducibility and inter-person reliability, and was optimized for use with whole canine blood which rendered an excellent degree of agreement with the use of serum. Field detectability of the ICT was assessed by screening 186 dogs from different CanL endemic areas with both the SGH-ELISA and the ICT, and 154 longitudinally sampled dogs only with the ICT. The ICT results corresponded to the SGH-ELISA for most areas, depending on the statistical measure used. Furthermore, the ICT was able to show a clear seasonal fluctuation in the proportion of bitten dogs. Finally, we excluded cross-reactions between non-vector species and confirmed favorable cross-reactions with other L. infantum vectors belonging to the subgenus Larroussius. CONCLUSIONS/SIGNIFICANCE: We have successfully optimized the ICT, now also suitable to be used with whole canine blood. The test is able to reflect the seasonal fluctuation in dog exposure and showed a good detectability in a field population of naturally exposed dogs, particularly in areas with a high seroprevalence of bitten dogs. Furthermore, our study showed the existence of favorable cross-reactions with other sand fly vectors thereby expanding its use in the field.


Assuntos
Doenças do Cão/diagnóstico , Imunoensaio/métodos , Insetos Vetores/fisiologia , Leishmaniose/veterinária , Phlebotomus/fisiologia , Animais , Doenças do Cão/sangue , Doenças do Cão/parasitologia , Cães , Feminino , Insetos Vetores/parasitologia , Leishmania infantum/fisiologia , Leishmaniose/sangue , Leishmaniose/diagnóstico , Leishmaniose/parasitologia , Camundongos Endogâmicos BALB C , Phlebotomus/parasitologia
15.
Insect Biochem Mol Biol ; 115: 103245, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31604119

RESUMO

The amine-binding properties of sand fly salivary yellow-related proteins (YRPs) were described only in Lutzomyia longipalpis sand flies. Here, we experimentally confirmed the kratagonist function of YRPs in the genus Phlebotomus. We utilized microscale thermophoresis technique to determine the amine-binding properties of YRPs in saliva of Phlebotomus perniciosus and P. orientalis, the Old-World vectors of visceral leishmaniases causative agents. Expressed and purified YRPs from three different sand fly species were tested for their interactions with various biogenic amines, including serotonin, histamine and catecholamines. Using the L. longipalpis YRP LJM11 as a control, we have demonstrated the comparability of the microscale thermophoresis method with conventional isothermal titration calorimetry described previously. By homology in silico modeling, we predicted the surface charge and both amino acids and hydrogen bonds of the amine-binding motifs to influence the binding affinities between closely related YRPs. All YRPs tested bound at least two biogenic amines, while the affinities differ both among and within species. Low affinity was observed for histamine. The salivary recombinant proteins rSP03B (P. perniciosus) and rPorASP4 (P. orientalis) showed high-affinity binding of serotonin, suggesting their capability to facilitate inhibition of the blood vessel contraction and platelet aggregation.


Assuntos
Aminas/metabolismo , Proteínas de Insetos/metabolismo , Phlebotomus/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Animais , Conformação Proteica , Glândulas Salivares/metabolismo , Eletricidade Estática
16.
PLoS Negl Trop Dis ; 13(10): e0007712, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31626654

RESUMO

BACKGROUND: Phlebotomus (Larroussius) guggisbergi is among the confirmed vectors for cutaneous leishmaniasis (CL) transmission in Kenya. This scarring and stigmatizing form of leishmaniasis accounts for over one million annual cases worldwide. Most recent CL epidemics in Kenya have been reported in Gilgil, Nakuru County, where the disease has become a public health issue. However, little is known about the factors that drive its transmission. Here, we sought to determine the occurrence, distribution and host blood feeding preference of the vectors, and to identify Leishmania species and infection rates in sandflies using molecular techniques. This information could lead to a better understanding of the disease transmission and improvement of control strategies in the area. METHODOLOGY/ PRINCIPAL FINDINGS: An entomological survey of sandflies using CDC light traps was conducted for one week per month in April 2016, and in June and July 2017 from five villages of Gilgil, Nakuru county; Jaica, Sogonoi, Utut, Gitare and Njeru. Sandflies were identified to species level using morphological keys and further verified by PCR analysis of cytochrome c oxidase subunit I (COI) gene. Midguts of female sandflies found to harbour Leishmania were ruptured and the isolated parasites cultured in Novy-MacNeal-Nicolle (NNN) media overlaid with Schneider's insect media to identify the species. Leishmania parasite screening and identification in 198 randomly selected Phlebotomus females and parasite cultures was done by PCR-RFLP analysis of ITS1 gene, nested kDNA-PCR and real-time PCR-HRM followed by sequencing. Bloodmeal source identification was done by real-time PCR-HRM of the vertebrate cytochrome-b gene. A total of 729 sandflies (males: n = 310; females: n = 419) were collected from Utut (36.6%), Jaica (24.3%), Sogonoi (34.4%), Njeru (4.5%), and Gitare (0.1%). These were found to consist of nine species: three Phlebotomus spp. and six Sergentomyia spp. Ph. guggisbergi was the most abundant species (75.4%, n = 550) followed by Ph. saevus sensu lato (11.3%, n = 82). Sandfly species distribution across the villages was found to be significantly different (p<0.001) with Jaica recording the highest diversity. The overall Leishmania infection rate in sandflies was estimated at 7.07% (14/198). Infection rates in Ph. guggisbergi and Ph. saevus s.l. were 9.09% (12/132) and 3.57% (2/56) respectively. L. tropica was found to be the predominant parasite in Gilgil with an overall infection rate of 6.91% (13/188) in Ph. guggisbergi (n = 11) and Ph. saevus s.l. (n = 2) sandflies. However, PCR analysis also revealed L. major infection in one Ph. guggisbergi specimen. Bloodmeal analysis in the 74 blood-fed sandflies disclosed a diverse range of vertebrate hosts in Ph. guggisbergi bloodmeals, while Ph. saevus s.l. fed mainly on humans. CONCLUSIONS/ SIGNIFICANCE: The high infection rates of L. tropica and abundance of Ph. guggisbergi in this study confirms this sandfly as a vector of L. tropica in Kenya. Furthermore, isolation of live L. tropica parasites from Ph. saevus s.l. suggest that there are at least three potential vectors of this parasite species in Gilgil; Ph. guggisbergi, Ph. aculeatus and Ph. saevus s.l. Molecular identification of L. major infections in Ph. guggisbergi suggested this sandfly species as a potential permissive vector of L. major, which needs to be investigated further. Sandfly host preference analysis revealed the possibility of zoonotic transmissions of L. tropica in Gilgil since the main vector (Ph. guggisbergi) does not feed exclusively on humans but also other vertebrate species. Further investigations are needed to determine the potential role of these vertebrate species in L. tropica and L. major transmission in the area.


Assuntos
Leishmania major/fisiologia , Leishmania tropica/fisiologia , Leishmaniose Cutânea/transmissão , Phlebotomus/parasitologia , Psychodidae/parasitologia , Animais , Entomologia , Feminino , Humanos , Quênia/epidemiologia , Leishmaniose Cutânea/epidemiologia , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
17.
Infect Genet Evol ; 76: 104073, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31629887

RESUMO

Visceral leishmaniasis (VL), the most severe form of the disease, is caused by Leishmania donovani in the Indian sub-continent (ISC). Whole genome sequencing studies revealed that two parasite populations exist in the ISC: a main population named the Core Group (CG) found mostly in the lowlands, and a new, genetically different subpopulation called ISC1. Parasites belonging to the CG were shown to be responsible for the recent epidemics, while the ISC1 variant was originally identified in hilly districts of Nepal and was later on increasingly found in the lowlands. Importantly, the ISC1 and CG isolates differ in their drug susceptibility and virulence signatures, suggesting that ISC1 constitutes an emerging and functionally different variant of L. donovani. In present study we aimed to address the potential of ISC1 transmission by the natural vector of L. donovani in the lowlands, Phlebotomus argentipes. By experimental infection of sand flies with parasites of the different genotypes, we demonstrate that ISC1 and CG strains are developing similarly in P. argentipes, suggesting that P. argentipes is a fully competent vector for ISC1 parasites. Integration of previous and current findings shows thus that ISC1 is a new and different variant of L. donovani, fully adapted to spread in the ISC through the main vector. This information is directly useful for managers of the elimination program. Furthermore, integration of our successive studies (genotyping, phenotyping and vector competence) demonstrates the relevance of molecular surveillance and should be of interest for scientists working on vector borne diseases and control managers.


Assuntos
Leishmania donovani/classificação , Leishmaniose Visceral/transmissão , Phlebotomus/parasitologia , Animais , Feminino , Humanos , Índia , Insetos Vetores/parasitologia , Leishmania donovani/genética , Leishmania donovani/isolamento & purificação , Filogenia
18.
BMC Res Notes ; 12(1): 566, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511056

RESUMO

OBJECTIVES: Infection with the causative agent of visceral leishmaniasis (VL) may be either symptomatic or asymptomatic. In this study we aimed at investigating the prevalence of asymptomatic infections of leishmania in non-endemic villages in Gedaref state, Sudan. A descriptive cross-sectional study conducted during September and October 2014. Blood samples were collected for serological and molecular analysis. Sticky-traps, knockdown spray and CDC-miniature light traps were used for the collection of sandflies. RESULTS: Ninety-Five participants were included; 52 from Abukishma, 15 Algadamblia Tirfa, 25 Abualnaja and 3 were from Algadamblia Aljabal. Females constituted 56 (58.9%) of the study participants while males were 39 (41.1%). The most frequent age group was > 40-years (54.7%). Balanites/Acacia trees were the most planted tree inside the houses; 78 (82.1%). Also, 85 (89.5%) of the participants breed animals inside the house. DAT test revealed 5 positive participants (5.2%). 4/5 DAT positive were past VL infection. PCR detected 35 (36.8%) positive participants. A total of 31/35 was considered asymptomatic infections based on PCR. Households planted Balanites/Acacia trees or breed domestic animals were found in high percentages with L. donovani PCR positive participants (60.1%, 91.4%). No statistically significant was found for VL associated risk factors and VL asymptomatic participants.


Assuntos
Infecções Assintomáticas/epidemiologia , Leishmania donovani/genética , Leishmaniose Visceral/epidemiologia , Acacia/parasitologia , Adulto , Animais , Estudos Transversais , DNA de Protozoário/genética , Feminino , Geografia , Humanos , Leishmania donovani/fisiologia , Leishmaniose Visceral/sangue , Leishmaniose Visceral/parasitologia , Masculino , Phlebotomus/parasitologia , Reação em Cadeia da Polimerase , Prevalência , Sudão/epidemiologia
19.
PLoS Negl Trop Dis ; 13(9): e0007724, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31525195

RESUMO

BACKGROUND: Visceral leishmaniasis (VL) is a parasitic disease, transmitted by the sand fly species Phlebotomus argentipes in the Indian sub-continent. Effective vector control is highly desirable to reduce vector density and human and vector contact in the endemic communities with the aim to curtail disease transmission. We evaluated the effect of long lasting insecticide treated bed nets (LLIN) and bed nets impregnated with slow-release insecticide tablet K-O TAB 1-2-3 (jointly insecticide-treated nets or ITN) on VL incidence in a highly endemic sub-district (upazila) in Bangladesh. METHODS: Several distributions of LLIN or K-O TAB 1-2-3 for self-impregnation of bed nets at home took place in Fulbaria upazila, Mymensigh district from 2004 to 2008 under three research projects, respectively funded by CDC, Atlanta, USA (2004) and WHO-TDR, Geneva, Switzerland (2006 & 2008). We included all households (n = 8142) in the 20 villages that had benefited in the past from one of these interventions (1295 donated LLIN and 11,918 local bed nets impregnated with K-O TAB 1-2-3) in the "exposed cohort". We recruited a "non-exposed cohort" in villages with contemporaneously similar incidence rates who had not received such vector control interventions (7729 HHs from nine villages). In both cohorts, we visited all families house to house and ascertained any VL cases for the 3 year period before and after the intervention. We evaluated the incidence rate (IR) of VL in both cohorts as primary endpoint, applying the difference-in-differences method. RESULTS: The study identified 1011 VL cases (IR 140.47/10,000 per year [py]) before the intervention, of which 534 and 477 cases in the intervention and control areas respectively. The IR was 144.13/10,000 py (534/37050) and 136.59/10,000 py (477/34923) in the intervention and control areas respectively, with no significant difference (p = 0.3901) before the intervention. After the intervention, a total of 555 cases (IR 77.11/10,000 py) were identified of which 178 (IR 48.04/10,000 py) in the intervention and 377 (107.95/10,000 py) in the control area. The intervention area had a significant lower IR than the control area during follow up, rate difference = -59.91, p<0.0001. The IR during follow up was significantly reduced by 96.09/10,000 py in the intervention area (p<0.0001) and 28.63/10,000 py in control area (p<0.0001) compared to baseline. There was a strong and significant overall effect of the ITN intervention, δ = -67.45, p <0.0001. Sex (OR = 1.36, p<0.0001) and age (OR = 0.99, p<0.0001) also had a significant effect on VL incidence. Male had a higher risk of VL than female and one year increase in age decreased the likelihood of VL by about 0.92%. Two third of the VL incidence occurred in the age range 2 to 30 years (median age of VL patients was 17 years). CONCLUSION: VL incidence rate was significantly lower in the ITN intervention cohort compared to control in Bangladesh. Some bias due to more intense screen-and-treat activities or other interventions in the intervention area cannot be ruled out. Nonetheless, given their feasibility and sustainability, ITNs should be considered for integrated vector control during the maintenance phase of the VL elimination programme.


Assuntos
Controle de Insetos/métodos , Mosquiteiros Tratados com Inseticida , Leishmaniose Visceral/prevenção & controle , Adolescente , Adulto , Animais , Bangladesh/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Lactente , Insetos Vetores , Inseticidas , Leishmaniose Visceral/epidemiologia , Masculino , Pessoa de Meia-Idade , Nitrilos , Phlebotomus , Piretrinas , Estudos Retrospectivos
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