Diversity of sandflies in Vidarbha region of Maharashtra, India, a region endemic to Chandipura virus encephalitis

Background & objectives: Sandflies are implicated as vectors of Chandipura virus (CHPV) (Vesiculovirus: Rhabdoviridae). The virus is prevalent in central India including Vidarbha region of Maharashtra. CHPV causes encephalitis in children below 15 yr of age with case fatality rates ranging from 56 to 78 per cent. The present study was undertaken to determine the sandfly fauna in the CHPV endemic Vidharba region. Methods: A year round survey of sandflies was conducted at 25 sites in three districts of Vidarbha region. Sandflies were collected from their resting sites using handheld aspirators and identified using taxonomical keys. Results: A total of 6568 sandflies were collected during the study. Approximately 99 per cent of the collection belonged to genus Sergentomyia, which was represented by Ser. babu, Ser. bailyi and Ser. punjabensis. Genus Phlebotomus was represented by Ph. argentipes and Ph. papatasi. Ser. babu was the predominant species (70.7%) collected during the study. Ph. argentipes was detected in four villages with 0.89 per cent, whereas Ph. papatasi was detected in only one village with 0.32 per cent of the total collection. CHPV could not be isolated despite processing all the sandflies for virus isolation in cell culture. Interpretation & conclusions: The present study showed influence of higher temperature and relative humidity on sandfly population dynamics. An important observation during the study was the absence or decline in the population of Ph. papatasi and Ph. argentipes in the study area. Surge in Sergentomyia population and their breeding/resting in close vicinity to humans pose a concern as they are known to harbour CHPV and other viruses of public health importance

Protease inhibitors as a potential agent against visceral Leishmaniasis: A review to inspire future study

Abstract Leishmaniasis is transmitted by sandfly which carries the intracellular protozoa in their midgut. Among visceral, cutaneous and mucocutaneous leishmaniasis, visceral type that is caused by Leishmania donovani is the most lethal one. Findings of leishmanial structure and species took place in 19th century and was initiated by Donovan. Leishmaniasis is still a major concern of health issues in many endemic countries in Asia, Africa, the Americas, and the Mediterranean region. Worldwide1.5-2 million new cases of cutaneous leishmaniasis and 500,000 cases of visceral leishmaniasis are reported each year. Leishmaniasis is endemic in nearly 90 countries worldwide and close to 12 million new cases of leishmaniasis are reported worldwide annually. Studies on antileishmanial drug development is of major concern as leishmaniasis are the second largest parasitic killer in the world and the available drugs are either toxic or costly. The major surface GP63 protease, also known as Zinc- metalloproteases present on the surface of leishmanial promastigotes, can be targeted for drug development. Protease inhibitors targeting such surface proteases show promising results. Different protease inhibitors have been isolated from marine actinobacteria against many infectious diseases. Metabolites produced by these actinobacteria may have greater importance for the discovery and development of new antileishmanial drugs. Hence, this review discusses the background, current situation, treatment, and protease inhibitors from marine actinobacteria for drug development against GP63 molecules.

Epidemiological investigation on a visceral leishmaniasis case in Zhengzhou City of Henan Province / 中国血吸虫病防治杂志

Objective To perform an epidemiological investigation on a case with visceral leishmaniasis in Zhengzhou City, Henan Province, and to identify the source of infection, so as to illustrate the transmission chain and assess the risk of local leishmaniasis transmission. Methods The medical data were collected from a case with visceral leishmaniasis in Zhengzhou City, and the patient’s bone marrow smears were detected by microscopy. Serum anti-Leishmania antibody test and PCR assay were performed among high-risk residents and all dogs in the village where the patient lived. Sandflies were captured using light traps and artificial traps, and the captured female Phlebotomus chinensis was subjected to PCR assay. The internal transcribed spacer 1 (ITS1) gene was amplified with a nested PCR assay using the genomic DNA extracted from visceral leishmaniasis patients, positive dogs and sandflies, and the sequences were aligned with those download from NCBI. In addition, a phylogenetic tree was created based on the ITS1 gene. Results The visceral leishmaniasis patient had recurrent irregular fever, reduced complete blood counts, low hemoglobin, and a large number of Leishmania amastigotes in bone marrow smears, and was therefore diagnosed as visceral leishmaniasis. Both rk39 rapid diagnostic test and PCR assay tested negative among 324 residents living neighboring the patient’s residence, while 21.39% (43/201) dogs were positive for rk39 rapid diagnostic test and 13.93% (28/201) positive for PCR assay. There were 17 female Ph. chinensis tested positive for Leishmania (0.82%) by PCR assay, and the ITS gene sequences from visceral leishmaniasis patients, positive dogs and sandflies shared a 100% homology with L. infantum. The Leishmania species was therefore characterized as L. infantum. Conclusions L. infantum infection occurs in visceral leishmaniasis patients, dogs and sandflies in Zhengzhou City, indicating a complete transmission chain and a high transmission risk of visceral leishmaniasis by L. infantum. Intensified control measures are required to prevent local transmission of leishmaniasis in Zhengzhou City.

Sandfly fauna and ecological analysis of Phlebotomus orientalis and Phlebotomus martini in the lowland foci of visceral leishmaniasis in Somali Regional State, southeast Ethiopia

To identify the sandfly fauna and analyze ecology of sandfly vector(s) of visceral leishmaniasis in three districts of Somali Regional State, southeast Ethiopia. Methods: Sandflies were collected from four sampling habitats, including indoor, peri-domestic, farm field and mixed forest using light and sticky traps in July 2016, and February and April 2017 in Liben and Dawa zones in the Somali Regional State, southeastern Ethiopia. Results: In total, 4 367 sandfly specimens, belonging to 12 species (three Phlebotomus spp. and nine Sergentomyia spp.) were identified. Phlebotomus (P.) heischi, P. orientalis, and P. martini constituted 45.7%, 31.1%, and 23.1% of the sandfly collection, respectively. There were significant differences in the median number of P. orientalis, and P. martini captured per CDC trap/night between the three sampling districts (P<0.05). In light trap capture, collection habitats had significant effects on the abundance of P. orientalis, and P. martini (P<0.05). More median numbers of P. orientalis, and P. martini species were collected in agricultural fields followed by mixed forest and peri-domestic habitats. P. orientalis and P. martini were caught more in outdoor than indoor habitats, suggesting exophilic behaviour. Conclusions: The study demonstrated that the presence of P. orientalis and P. martini are probable vectors of visceral leishmaniasis in this new focus. The findings of our study will improve the understanding of the dynamics of visceral leishmaniasis transmission and will facilitate the implementation of integrated disease control measures based on ecological knowledge of visceral leishmaniasis vector in Liben and Dawa zones and its surrounding regions.

Exposure to Leishmania spp. infection and Lutzomyia spp. in individuals living in an area endemic for visceral leishmaniasis in Brazil

Abstract INTRODUCTION: This study aimed to investigate human exposure to Leishmania spp. infection and sandflies in an area endemic for the disease. METHODS: The presence of antibodies specific for Leishmania spp. and saliva of Lutzomyia spp. and that of L. infantum DNA in blood were evaluated. RESULTS: Antibodies against Leishmania spp. and sandfly saliva were observed in 20.8% and 37.7% of individuals, respectively. DNA of Leishmania spp. was amplified from the blood of one patient. CONCLUSIONS: The results suggest that Leishmania spp. infection may be underdiagnosed in this area.

Sandfly fauna and ecological analysis of Phlebotomus orientalis and Phlebotomus martini in the lowland foci of visceral leishmaniasis in Somali Regional State, southeast Ethiopia

To identify the sandfly fauna and analyze ecology of sandfly vector(s) of visceral leishmaniasis in three districts of Somali Regional State, southeast Ethiopia. Methods: Sandflies were collected from four sampling habitats, including indoor, peri-domestic, farm field and mixed forest using light and sticky traps in July 2016, and February and April 2017 in Liben and Dawa zones in the Somali Regional State, southeastern Ethiopia. Results: In total, 4 367 sandfly specimens, belonging to 12 species (three Phlebotomus spp. and nine Sergentomyia spp.) were identified. Phlebotomus (P.) heischi, P. orientalis, and P. martini constituted 45.7%, 31.1%, and 23.1% of the sandfly collection, respectively. There were significant differences in the median number of P. orientalis, and P. martini captured per CDC trap/night between the three sampling districts (P<0.05). In light trap capture, collection habitats had significant effects on the abundance of P. orientalis, and P. martini (P<0.05). More median numbers of P. orientalis, and P. martini species were collected in agricultural fields followed by mixed forest and peri-domestic habitats. P. orientalis and P. martini were caught more in outdoor than indoor habitats, suggesting exophilic behaviour. Conclusions: The study demonstrated that the presence of P. orientalis and P. martini are probable vectors of visceral leishmaniasis in this new focus. The findings of our study will improve the understanding of the dynamics of visceral leishmaniasis transmission and will facilitate the implementation of integrated disease control measures based on ecological knowledge of visceral leishmaniasis vector in Liben and Dawa zones and its surrounding regions.

Use of Kisser glycerol gelatin to prepare microscope slides of Phlebotomine sandflies (Diptera: Psychodidae)

Abstract INTRODUCTION: Appropriate preservation of specimens is important for taxonomic identification. In sandfly research, various methods have been used for slide preparation; however, high cost, low commercial availability, and associated hazards make their use impossible in some studies. Therefore, the efficacy of Kisser glycerol gelatin for sandfly slide preparation was tested. METHODS: Kisser glycerol gelatin, as a substitute for Canada balsam and Berlese's fluid, was used for mounting sandflies. RESULTS: Forty-two mounted specimens were created and maintained even after 14 months. CONCLUSIONS: Use of Kisser glycerol gelatin is simple and efficient for preparing microscope slides of sandflies.

The current status of the Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) species complex

Lutzomyia longipalpis s.l. is a complex of sibling species and is the principal vector of American visceral leishmaniasis. The present review summarises the diversity of efforts that have been undertaken to elucidate the number of unnamed species in this species complex and the phylogenetic relationships among them. A wide variety of evidence, including chemical, behavioral and molecular traits, suggests very recent speciation events and complex population structure in this group. Although significant advances have been achieved to date, differential vector capacity and the correlation between structure of parasite and vector populations have yet to be elucidated. Furthermore, increased knowledge about recent epidemiological changes, such as urbanisation, is essential for pursuing effective strategies for sandfly control in the New World.

First description of Leishmania (Viannia) infection in Evandromyia saulensis, Pressatia sp. and Trichophoromyia auraensis (Psychodidae: Phlebotominae) in a transmission area of cutaneous leishmaniasis in Acre state, Amazon Basin, Brazil

Studies on the sandfly fauna to evaluate natural infection indexes are still limited in the Brazilian Amazon, a region with an increasing incidence of cutaneous leishmaniasis. Here, by using a multiplex polymerase chain reaction directed to Leishmania kDNA and hybridisation, we were able to identify L. (Viannia) subgenus in 12 out of 173 sandflies captured in the municipality of Rio Branco, Acre state, revealing a positivity of 6.94%. By sequencing the Leishmania 234 bp-hsp70 amplified products from positive samples, infection by L. (V.) braziliensis was confirmed in five sandflies: one Evandromyia saulensis, three Trichophoromyia auraensis and one Pressatia sp. The finding of L. (Viannia) DNA in two Ev. saulensis corresponds to the first record of possible infection associated with this sandfly. Moreover, our study reveals for the first time in Brazil, Th. auraensis and Pressatia sp. infected by L. (Viannia) parasites.

Worldwide risk factors in leishmaniasis

Recently, vector-borne parasitic diseases such as leishmaniasis have been emerged or re-emerged in many geographical areas and resulted in global health and economic concerns that involve humans, domestic animals and wild life. The ecology and epidemiology of leishmaniasis are affected by the between host, reservoir and vector (human, animal and sandfly) and the environment. Important drivers for the emergence and spread of leishmaniasis include environmental factors such as alterations in temperature and water storage, irrigation habits, deforestation, climate changes, immunosuppression by HIV or organ transplant, development of drug resistance, increase traveling to endemic regions and dog importation. War, poor socio-economic status and low level household are also major contributors to the spread of this disease. Health education via the public media and training should be implemented by international organizations and governmental agencies in collaboration with research institutions. Fully protection during transmission season, using bednets and insecticides and reservoirs' control should be also mentioned in the planning. Based on the findings of the recent studies and high prevalence of leishmaniasis, it is concluded that serious public health monitoring should be considered.

Population dynamics of the mood-sucking insects and detection of pathogens in the rodents from xisha islands of china / 第二军医大学学报

Objective To investigate the popukton dynamics of blood-sucking insects and detect the pathogen of rodents in Xisha Islands of China, so as to provide information for prevention and control of infectious diseases in the area. Methods From January to July in 2014. we collected blood-sucking msccis in Yongxing and Shi Islands twice a month using light traps. The specimens were identified by morphologic characters and molecular markers. Meanwhile, the population size was calculated. The pathogenic infections of rodints were detected by immuno-collcadal gold chromatographic test stnps and PCR assay. And the ectoparasates in the rodents were initially identified by morphologic characters. Krsilts The dominant species of blood-sucking insects in Xisha Islands were species of Genus Cutex, Armine res and Cuticoides, and in Apnl the population density of biting midge was the highest (55. 55%. 6 984/12 573). Phlebotomine sandfly specimen was also collected and identified as Sergentomyia baily (n= 11) by mtDNA-CO I sequences. The positive rates of Staphylococcus aureus aiterotoxin type A and Botulinum toxin type A were 3. 45% (1/29) and 14.00% (7/50) in the rodent serum samples, while all the samples were negative for Tsutsugamushi disease and Plague antibodies. Srta58 gene of Rickettsia tsutsugamushi was amplified by nested FCR m 70 rodent’s spkren tissues, with the positive rate bang 11. 43% (8/70). A total of 248 ectoparasites were collected, and 93.55% (232/248) of them was gamasid mites. Conclusion The population dynamics of blood-sucking insects has no obvious change. Phtebotamme sandflies has been first recorded in Xisha Islands. The infection rates by Rickettsia tsutsugaimslx i and two bacterial toxins are high.

Effect of Leishmania spp infection on the survival, life expectancy, fecundity and fertility of Lutzomyia longipalpiss.l. and Lutzomyia pseudolongipalpis

We evaluated the effects of Leishmaniaspp infection on several population parameters of Lutzomyia longipalpis sensu lato andLutzomyia pseudolongipalpis, vectors of visceral leishmaniasis in Venezuela, under experimental conditions during the first post-feeding period. Females of both species were allowed to feed and engorge on a suspension of fresh washed human red blood cells in foetal calf serum. These blood cells were either non-infected or infected with one of the fourLeishmaniaspp strains and were offered through a chicken skin membrane. The longevity, life expectancy and the fecundity of uninfected flies were similar in both species, but the fertility was significantly lower in uninfected Lu. longipalpis females. In all cases, the infection of Lu. longipalpis and Lu. pseudolongipalpis by the Leishmaniastrains resulted in significant detrimental effects, which exerted a fitness cost expressed by reduced survival and life expectancy, as well as decreased fertility and fecundity compared with the control groups. Nevertheless, differences in these parameters were observed between these vector species depending on whether they were infected with the autochthonous Venezuelan Leishmania infantum strain (NESA) or the Brazilian reference strain (PP75). The experimental data obtained agree with field data on the natural infection of these vector species and the significance of this scenario is discussed.

Sandfly species diversity in association with human activities in the Kani tribe settlements of the Western Ghats, Thiruvananthapuram, Kerala, India

Sandfly prevalence in the Kani tribe settlements of Western Ghats in India was investigated. A total of 1,279 sandflies comprising 17 species was obtained. Sandfly abundance showed a negative correlation (r = -0.97, p = 0.003) with increase in altitudinal ranges from 0-1,000 m. When sandfly samples were grouped according to landscape characteristics of the location, the estimated Shannon-Weiner index (H) and species richness index (S) were high and species evenness index (J) was low in settlements located at 0-300 m altitudinal range. On the contrary, the values of H and J were high, while S was low at 301-600 m altitudinal range. With further increase in altitude, species diversity, S and J were low. Though the relative abundance of sandflies decreased with increase in altitude, the influence of altitudinal variation could not be attributed to determine sandfly diversity, since the number of sampling units were not uniform at all the altitudinal gradients due to nonavailability of suitable resting shelters. Sandfly species showed great aggregation at 0-300 m altitude interval, where not only the number of settlements were maximum (n = 19), but also the environmental conditions favoured sandfly abundance due to the concentration of tribal settlements, human dwellings and his activities.

DETECTION OF Leishmania (Viannia) IN Nyssomyia neivai AND Nyssomyia whitmani BY MULTIPLEX POLYMERASE CHAIN REACTION, IN SOUTHERN BRAZIL / Detecção de Leishmania (Viannia) em Nyssomyia neivai e Nyssomyia whitmani por Multiplex Reação em Cadeia da Polimerase, no sul do Brasil

Sandflies transmit pathogens of leishmaniasis. The natural infection of sandflies by Leishmania (Viannia) was assessed in municipalities, in the state of Paraná, in Southern Brazil. Sandflies were collected with Falcão and Shannon traps. After dissection in search of flagellates in digestive tubes and identification of the species, female sandflies were submitted to the Multiplex Polymerase Chain Reaction (multiplex PCR) for detection of the fragment of the kDNA of Leishmania (Viannia) and the fragment from the IVS6 cacophony gene region of the phlebotomine insects. The analysis was performed in pools containing seven to 12 guts from females of the same species. A total of 510 female sandflies were analyzed, including nine Migonemyia migonei, 17 Pintomyia fischeri, 216 Nyssomyia neivai, and 268 Nyssomyia whitmani. Although none of the females was found naturally infected by flagellates through dissection, the fragment of DNA from Leishmania (Viannia) was shown by multiplex PCR in one sample of Ny. neivai (0.46%) and three samples of Ny. whitmani (1.12%). It was concluded that Ny. neivai and Ny. whitmani are susceptible to Leishmania infection, and that multiplex PCR can be used in epidemiological studies to detect the natural infection of the sandfly vector, because of its sensitivity, specificity and feasibility.

Flebotomíneos transmitem os patógenos das leishmanioses. Foi avaliada a infecção natural de flebotomíneos por Leishmania (Viannia) em municípios do Estado do Paraná, sul do Brasil. Os flebotomíneos foram coletados com armadilhas de Falcão e Shannon. Após dissecação para pesquisa de flagelados no tubo digestório e identificação das espécies, as fêmeas de flebotomíneos foram submetidas a Multiplex Reação em Cadeia da Polimerase (multiplex PCR) para a detecção do fragmento do kDNA de Leishmania (Viannia) e do fragmento do gene IVS6 da cacofonia de flebotomíneos. A análise foi realizada em pools contendo sete a 12 tubos digestórios de fêmeas da mesma espécie. Um total de 510 fêmeas foram analisadas, incluindo nove Migonemyia migonei, 17 Pintomyia fischeri, 216 Nyssomyia neivai e 268 Nyssomyia whitmani. Embora nenhuma fêmea tenha sido encontrada naturalmente infectada com flagelados pela dissecação, o fragmento de DNA de Leishmania (Viannia) foi mostrado por multiplex PCR em uma amostra de Ny. neivai (0,46%) e três amostras de Ny. whitmani (1,12%). Conclui-se que Ny. neivai e Ny. whitmani são suscetíveis à infecção por Leishmania, e que multiplex PCR, devido à sua sensibilidade, especificidade e viabilidade, pode ser utilizada em estudos epidemiológicos para a detecção da infecção natural do inseto vetor.

Ecology of cutaneous leishmaniasis in Sinai: linking parasites, vectors and hosts

Cutaneous leishmaniasis (CL) is a neglected clinical form of public health importance that is quite prevalent in the northern and eastern parts of Egypt. A comprehensive study over seven years (January 2005-December 2011) was conducted to track CL transmission with respect to both sandfly vectors and animal reservoirs. The study identified six sandfly species collected from different districts in North Sinai: Phlebotomus papatasi, Phlebotomus kazeruni, Phlebotomus sergenti, Phlebotomus alexandri, Sergentomyia antennata and Sergentomyia clydei. Leishmania (-)-like flagellates were identified in 15 P. papatasi individuals (0.5% of 3,008 dissected females). Rodent populations were sampled in the same districts where sandflies were collected and eight species were identified: Rattus norvegicus (n = 39), Rattus rattus frugivorous (n = 13), Rattus rattus alexandrinus (n = 4), Gerbillus pyramidum floweri (n = 38), Gerbillus andersoni (n = 28), Mus musculus (n = 5), Meriones sacramenti (n = 22) and Meriones crassus (n = 10). Thirty-two rodents were found to be positive for Leishmania infection (20.12% of 159 examined rodents). Only Leishmania major was isolated and identified in 100% of the parasite samples. The diversity of both the vector and rodent populations was examined using diversity indices and clustering approaches.

Leishmaniasis transmission: distribution and coarse-resolution ecology of two vectors and two parasites in Egypt

Introduction: In past decades, leishmaniasis burden has been low across Egypt; however, changing environment and land use has placed several parts of the country at risk. As a consequence, leishmaniasis has become a particularly difficult health problem, both for local inhabitants and for multinational military personnel. Methods: To evaluate coarse-resolution aspects of the ecology of leishmaniasis transmission, collection records for sandflies and Leishmania species were obtained from diverse sources. To characterize environmental variation across the country, we used multitemporal Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for 2005-2011. Ecological niche models were generated using MaxEnt, and results were analyzed using background similarity tests to assess whether associations among vectors and parasites (i.e., niche similarity) can be detected across broad geographic regions. Results: We found niche similarity only between one vector species and its corresponding parasite species (i.e., Phlebotomus papatasi with Leishmania major), suggesting that geographic ranges of zoonotic cutaneous leishmaniasis and its potential vector may overlap, but under distinct environmental associations. Other associations (e.g., P. sergenti with L. major) were not supported. Mapping suitable areas for each species suggested that northeastern Egypt is particularly at risk because both parasites have potential to circulate. Conclusions: Ecological niche modeling approaches can be used as a first-pass assessment of vector-parasite interactions, offering useful insights into constraints on the geography of transmission patterns of leishmaniasis. .

Phlebotomus (Legeromyia) multihamatus subg. nov., sp. nov. from Gabon (Diptera: Psychodidae)

During a research project aimed at the study of the Culicinae fauna of Gabon and carried out in the National Park of La Lopé, we captured an unknown sandfly male specimen (genus Phlebotomus) by CDC miniature light trap belonging to a new species for Science. Furthermore, the originality of his genitalia does not allow us to include this species in one of the existing subgenus, thus in this paper we propose the creation of a new subgenus, as Phlebotomus (Legeromyia) multihamatus sp. nov., subg. nov. described from the National Park of La Lopé, through one male captured with CDC miniature light trap. A new species and a new subgenus of sandfly is characterised by a short style with three spines, a paramere wearing a basal hook as well as a basal pouch and the absence of basal lobe on the coxite. The originality of the genitalia of the male gives way to discussion about potential primary homologies between P. multihamatus sp. nov. and Phlebotomus (Abonnencius) fortunatarum, Phlebotomus (Anaphlebotomus) stantoni and Phlebotomus (Euphlebotomus) argentipes, which should be verified for future studies. The discovery of this new species in Gabon must encourage the study of sandflies in this country.

Blood feeding patterns of Nyssomyia intermedia and Nyssomyia neivai (Diptera, Psychodidae) in a cutaneous leishmaniasis endemic area of the Ribeira Valley, State of São Paulo, Brazil

Introduction The aim of this study was to identify the blood feeding sources of Nyssomyia intermedia (Ny. intermedia) and Nyssomyia neivai (Ny. neivai), which are Leishmania vectors and the predominant sandfly species in the Ribeira Valley, State of São Paulo, Brazil, an endemic area for cutaneous leishmaniasis. Methods Specimens were captured monthly between February 2001 and December 2003 on a smallholding and a small farm situated in the Serra district in the Iporanga municipality. The blood meals of 988 engorged females were tested using the avidin-biotin immunoenzymatic enzyme-linked immunosorbent assay (ELISA). Seven blood meal sources were investigated: human, dog, chicken, bovine, pig, horse and rat. Results The results showed that among the females that fed on one or more blood sources, the respective percentages for Ny. intermedia and Ny. neivai, respectively, were as follows: human (23% and 36.8%), pig (47.4% and 26.4%), chicken (25.7% and 36.8%) and dog (3.9% and 0%), and the differences in the blood sources between the two species were statistically significant (p = 0.043). Conclusions Both species had predominant reactivity for one or two blood sources, and few showed reactivity indicating three or four sources. Many different combinations were observed among the females that showed reactivity for more than one source, which indicated their opportunistic habits and eclecticism regarding anthropic environmental conditions. .

Leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva

Leishmania parasites expose phosphatidylserine (PS) on their surface, a process that has been associated with regulation of host's immune responses. In this study we demonstrate that PS exposure by metacyclic promastigotes of Leishmania amazonensis favours blood coagulation. L. amazonensis accelerates in vitro coagulation of human plasma. In addition, L. amazonensis supports the assembly of the prothrombinase complex, thus promoting thrombin formation. This process was reversed by annexin V which blocks PS binding sites. During blood meal, Lutzomyia longipalpis sandfly inject saliva in the bite site, which has a series of pharmacologically active compounds that inhibit blood coagulation. Since saliva and parasites are co-injected in the host during natural transmission, we evaluated the anticoagulant properties of sandfly saliva in counteracting the procoagulant activity of L. amazonensis . Lu. longipalpis saliva reverses plasma clotting promoted by promastigotes. It also inhibits thrombin formation by the prothrombinase complex assembled either in phosphatidylcholine (PC)/PS vesicles or in L. amazonensis . Sandfly saliva inhibits factor X activation by the intrinsic tenase complex assembled on PC/PS vesicles and blocks factor Xa catalytic activity. Altogether our results show that metacyclic promastigotes of L. amazonensis are procoagulant due to PS exposure. Notably, this effect is efficiently counteracted by sandfly saliva.

Phlebotomine sandfly fauna and natural Leishmania infection rates in a rural area of Cerrado (tropical savannah) in Nova Mutum, State of Mato Grosso in Brazil

Introduction American cutaneous leishmaniasis (ACL) has been reported in every municipality of the State of Mato Grosso, Brazil, but the transmission epidemiology remains poorly understood. Our study was developed in a rural area of the Nova Mutum municipality where four autochthonous cases of ACL were reported in 2009. Our aims were to describe the local phlebotomine sandfly fauna and to investigate the infection rates and infecting Leishmania species in the captured sandflies. Methods Entomological captures were performed bimonthly at 10 fixed sites close to the edge of a forested area between June 2011 and April 2012. Results A total of 3,743 phlebotomine sandflies belonging to 31 distinct species were captured. Approximately 75% of the specimens were females. The most abundant species (45.4%) was Lutzomyia antunesi, which was consistently captured at every site. Species that are epidemiologically important for ACL, such as L. flaviscutellata, L. whitmani and L. umbratilis, were also captured. L. antunesi and L. ubiquitalis were naturally infected by Leishmania braziliensis or Le. guyanensis, with minimum infection rates of 0.88% and 6.67%, respectively. Surprisingly, L. antunesi was infected by Le. infantum (synonym chagasi). Conclusions The natural infection of L. antunesi and L. ubiquitalis by Leishmania sp. suggests that these species might play a role in the zoonotic cycle of ACL in Nova Mutum. The presence of Le. infantum in L. antunesi suggests that there may be a risk of an outbreak of visceral leishmaniasis (VL) in Nova Mutum. .