Phlebotomine Sand Flies Research Articles

The role of protists, nematodes and mites as natural control agents of sandfly populations

The Phlebotomine sandflies (Diptera, Psychodidae) are hematophagous insects of immense medical and veterinary importance. Since World War II, the intensive use of chemicals to suppress and control sandfly populations resulted in development of insecticide resistance and resurgence among the sandfly populations worldwide. The use of chemicals also negatively impacted diverse non-target organisms, overall agroecosystem, crop productivity, human health etc. Due to the multiple adverse effects of the chemical compounds, more eco-friendly approaches have been evaluated. The application of entomopathogenic organisms such as nematodes, protists or mites as biocontrol agents has been vastly explored and applied in the field of forestry and agriculture. In comparison, only a little attention was given to blood-sucking insects such as sandflies. This review summarizes the findings related to the detection and use of entomopathogenic protists, nematodes, and mites in the field of biological control of sandflies. It highlights the potential of these organisms to be further explored and used for biocontrol of immature and adult stages of sandflies.

Evaluation of intralesional treatment in american tegumentary leishmaniasis in the amazon region: results and perspectives

American Tegumentary Leishmaniasis (ATL) is an infectious disease transmitted to humans by the bite of infected phlebotomine sand flies, commonly known as "sand flies." In Brazil, ATL is a significant public health challenge, with a higher prevalence in the northern region, a predominance of males aged 20 to 40 years, and a higher incidence among the mixed-race population. Methodology: The study was conducted under the Education through Work for Health Program (PET-Saúde) in Santarém, Pará, between August and December 2022. Results: The predominant profile of ATL patients was adult male rural workers with cutaneous lesions mainly on the lower limbs. The most common clinical form was localized cutaneous lesion, representing over 90% of cases. Intralesional treatment with meglumine antimoniate was well-tolerated by patients, with few local side effects and a successful therapeutic response in most cases. Discussion: The results corroborated with the literature, showing the endemic profile of ATL in the Amazon region. Intralesional treatment proved to be effective and well-tolerated, being a relevant option for areas with limited resources and difficulties in accessing healthcare. Conclusion: The study provides evidence that intralesional treatment with meglumine antimoniate is an effective therapeutic option. Its high adherence suggests its consideration in public health policies for disease treatment. It is recommended that future studies expand the sample size and follow-up period to obtain more comprehensive information about this therapeutic approach.

Canine Leishmaniasis (CanL); a public health threat in Ghana

Canine Leishmaniasis (CanL) is a protozoal disease caused by Leishmania species and transmitted by the female phlebotomine sand fly (which serves as a vector for the parasite) among animals and humans. The disease is of great importance to public health, due to its zoonotic nature, and the role of dogs as the natural reservoir of the disease. An important factor that helps in the continuous perpetuation of the parasite and for that matter the disease is the ability of the infective form of the parasite (metacyclic promastigote) to transform into amastigote in the host cells, and outsmart the host’s immune mechanism. These phenomena among other factors, poses a great risk of spreading the disease to susceptible hosts (humans and animals). Three forms of the disease have been identified, namely; visceral (VL), cutaneous (CL) and mucocutaneous (MCL). Leishmaniasis control has been categorized into direct method, targeted at infectious dogs and indirect method, targeted at the vector. In conclusion, human cutaneous leishmaniasis (HCL) is endemic in certain areas of the country, however, there is no data on cases of canine leishmaniasis in the country. It is recommended that, in discussing strategies to curb human leishmaniasis, stake-holders should factor in the role of dogs and for that reason, canine leishmaniasis (CanL).

Phlebotomine sand fly (Diptera: Phlebotominae) diversity in the foci of cutaneous leishmaniasis in the Surxondaryo Region of Uzbekistan: 50 years on

In Uzbekistan, the number of reported leishmaniasis cases is rising at the alarming rate. In this work, we studied the phlebotomine sand fly (Diptera: Phlebotominae) diversity in the foci of cutaneous leishmaniasis in the Surxondaryo Region of Uzbekistan and compared it with the data obtained for the same area 50 years ago, when infection prevalence was reportedly low. We found that the implicated vector for zoonotic leishmaniasis, P. papatasi, remained eudominant; the proportion of implicated anthroponotic leishmaniasis vector, P. sergenti, rose significantly from averaged 5.4 to 41.4%; Phlebotomus alexandri, a suspected visceral leishmaniasis vector, was eudominant at two sites, and a second suspected vector for this disease, P. longiductus, was newly recorded in the region. We conclude that the increase in the documented cases of cutaneous leishmaniasis in the Surxondaryo Region of Uzbekistan may be connected to the changes in fauna of sand flies vectoring Leishmania spp.

Diagnostic accuracy of serological rk-39 test for visceral Leishmaniasis: Systematic review and meta-analysis.

Visceral leishmaniasis (VL), or kala-azar, is a vector-borne tropical disease caused by a group of intracellular hemoflagellate protozoa belonging to the family of Trypanosomatide and the genus Leishmania. The disease is distributed around the world and transmitted via the bite of infected female Phlebotomine sandflies, and there is variation in the diagnostic accuracy. Therefore, this systematic review and meta-analysis aimed to determine the pooled global sensitivity and specificity of the rk-39 test and to evaluate if there is a difference between the different parts of the world. A systematic review and meta-analysis have been conducted on the diagnostic accuracy of dermoscopy. After setting eligibility criteria, literature was searched in four databases and one searching engine. Articles were screened, critically appraised, and extracted independently by two reviewers, and any disagreements were resolved with the involvement of a third person. The quality of the included studies had been assessed by the Quality Assessment of Diagnostic Accuracy Studies (QUADAS 2) tool. Pooled sensitivity and specificity were determined by bivariate random effect analysis. Heterogeneity was assessed by Higgins's I2, and when it was present, mitigation was conducted by using sensitivity analysis. A total of 409 studies were identified, and finally 18 articles were eligible for the review with a total sample size of 5, 253. The bivariate random effect meta-analysis of the 7 diagnostic accuracy studies showed a pooled sensitivity of 0.89 (0.76-0.95) and specificity of 0.86 (0.72-0.94). The +LR was 6.32 (95% CI: 2.85-14.02), the-LR was 0.13 (95% CI: 0.06-0.30), and the diagnostic odds ratio (DOR) was 47.8 (95% CI: 11.3-203.2). Abdel-Latif (2018) was both an outlier and influential for sensitivity, and Walter (2011) was both an outlier and influential for specificity, and removing them from sensitivity and specificity, respectively, was beneficial for reducing the heterogeneity. Rk-39 is found to have highly accurate measures in the diagnosis of visceral leishmaniasis. Both sensitivity and specificity were found to be highly accurate in the diagnosis of leishmaniasis, with a pooled sensitivity of 0.91 (0.88-0.93) and a pooled specificity of 0.89 (0.85-0.91). As we will use secondary data for the systematic review and meta-analysis, ethical concerns are not necessary.

Species, Natural Leishmania spp. Detection and Blood Meal Sources of Phlebotomine Sandflies (Diptera: Psychodidae: Phlebotominae) in Peridomiciles from a Leishmaniases Endemic Area of Brazil

Leishmaniases are important neglected tropical diseases caused by protozoans of the genus Leishmania spp. The female sandflies bite (Diptera: Psychodidae: Phlebotominae) is the main transmission form in the epidemiological chains of these diseases. Thus, studies on Phlebotominae subfamily are fundamental to improve the comprehension of the leishmaniases epidemiology, revealing relationships of these dipterans with the parasite and reservoirs. An entomological survey of Phlebotomine sandflies was carried out to investigate the fauna, Leishmania spp. DNA detection and blood meals sources of female sandflies captured in peridomiciles areas from a leishmaniases endemic area of São Paulo state, Brazil. A total of 637 Phlebotomine sandflies specimens were captured, and twelve species identified, some of them proven or suspected vectors of tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL). Evandromyia (Aldamyia) carmelinoi and Lutzomyia (Lutzomyia) longipalpis PCR positive to Leishmania (Leishmania) infantum kinetoplast minicircle DNA (kDNA) were identified. Also, Leishmania (Leishmania) amazonensis kDNA was found in Evandromyia (Aldamyia) lenti and Lu. (Lu.) longipalpis. Regarding blood meals source, DNA of swine, humans, dogs, cattle, chickens, and opossums were detected in the midgut of Phlebotomine sandflies females captured in the study area. Our results highlight ecological relationships among different species of Phlebotomine sandflies, domestic and wild-synanthropic vertebrates (including humans) and two Leishmania species in peridomiciles from a leishmaniases endemic area of Brazil.

The perfect storm: Cutaneous leishmaniasis in troops deployed in the Atlantic forest of Argentina.

American cutaneous leishmaniasis (ACL) is the most prevalent form of leishmaniasis, associated with an ulcerative and stigmatizing mucocutaneous pathology. This study assessed the incidence of Leishmania (Viannia) braziliensis in members of the Argentine Army who were exposed to sandfly bites in Iguazú National Park (INP), northeastern Argentina, during an outbreak of ACL in 2019, and the presence of Leishmania in rodents, opossums and phlebotomine sandflies collected in the area of exposure. Samples from military personnel, wild animals and phlebotomine sandflies were analysed. A total of 20 (40%) patients among the Army personnel and two Akodon montensis rodents (11%) were positive for the presence of Leishmania sp. genes by PCR, while Nyssomyia whitmani and Migonemyia migonei, competent vectors of Leishmania, were also found at the same site. Sequences of hsp70 DNA fragments obtained from human samples confirmed the identity of L. (V.) braziliensis. The risk to which military personnel carrying out activities in the forest are exposed is highlighted, and this risk extends to any worker and visitor who circulates without protection in the INP, coming into contact with transmission "hot spots" due to the concentration of vectors, reservoirs and/or parasites.

Efficiency of rLb6H recombinant protein from Leishmania (Viannia) braziliensis for the detection of canine visceral leishmaniasis

Introduction: Visceral leishmaniasis (VL) is a serious endemic disease in many tropical and subtropical countries, with a strong incidence in Brazil. The disease is transmitted by the bite of infected female phlebotomine sandflies, with dogs being the main urban reservoirs of the parasite. The diverse clinical profile and the long incubation period are challenges for the diagnosis of canine visceral leishmaniasis (CVL). Recombinant proteins from Leishmania spp. have been studied as antigens that can increase the accuracy of serological tests. Objective: To evaluate the diagnostic performance of the recombinant protein rLb6H, from Leishmania braziliensis, in comparison to the reference antigens rK39 and rK28, from L. donovani, prioritizing the identification of subclinical infected dogs. Material and Methods: Serum IgG reactivity to rLb6H, rK28, and rK39 recombinant proteins was assessed in dogs with previously parasitological confirmation of CVL, subdivided according to their clinical status, using immunoenzymatic assay (ELISA). Diagnostic accuracy of each ELISA was evaluated by receiver operating characteristic (ROC) curve analysis. Results: While all antigens showed a better performance in detecting CVL in symptomatic dogs (SD), detection of CVL in the oligosymptomatic (OD) and asymptomatic (AD) groups was lower, but rLb6H achieved high sensitivity for asymptomatic CVL. Interestingly, the most reactive CVL samples to rK28 were barely detected by rLb6H, while the less reactive to rK28, mostly from the AD group, presented higher reactivity to rLb6H. Conclusion: The recombinant protein rLb6H showed utility in the detection of asymptomatic CVL, displaying a complementary reactivity to rK39 and rK28. Thus, these results suggest that rLb6H could be incorporated into multi-antigen strategies, to increase diagnostic accuracy of CVL.

Enzyme-catalyzed kinetic resolution of racemic 1-octen-3-ol and field evaluation of its enantiomeric isomers as attractants of sandflies

Phlebotomine sand flies are medically important as vectors of the protozoan parasites that cause leishmaniasis and other bacterial and viral pathogens. Previous work demonstrated that both sexes of certain species of sandflies are attracted to 1-octen-3-ol (octenol). Since 1-octen-3-ol exists as two enantiomeric isomers ─ ((R)-(-)- (R-form) and (S)-(+)- (S-form), we tested the hypothesis that the two enantiomeric forms and racemic mixture (R/S) attracted different sand fly species. We carried out field trials in a leishmaniasis endemic foci in Baringo County, Kenya. In a randomized design, trap captures of sandflies in CDC light traps baited with the R-, S- and racemic (R/S) forms of 1-octen-3-ol in hexane varied with the form and dose of the compound. Interestingly, of the captured species, only Phlebotomus martini, the vector of the parasite causing visceral leishmaniasis, exhibited a dose-dependent response to octenol; captures of both sexes of the species being generally 1.7-fold higher with the R- than S-form. There was no significant effect of treatment on captures of Sergentomyia species (S. schwetzi, S. antennata, S, clydei). Our findings have implications for surveillance of sandfly populations as part of leishmaniasis epidemiologic investigation.

Characterization of West Nile virus Koutango lineage from phlebotomine sandflies in Kenya.

The West Nile virus (WNV), primarily transmitted by mosquitoes, is one of the most widespread flaviviruses globally, with past outbreaks occurring in the USA and Europe. Recent studies in parts of Africa, including Kenya, have identified the West Nile virus Koutango lineage (WN-KOUTV) among phlebotomine sandfly populations, however, our understanding of this virus remains limited. This study aimed to characterize WN-KOUTV from phlebotomine sandflies. Sandflies were sampled between 12th -16th March 2021 and 16th -20th March 2023 from six villages each in Baringo and Isiolo Counties, using CDC light traps. Female sandflies were taxonomically identified and pooled based on genus and site of collection. Virus isolation was performed in Vero cells. Viral genomes were determined using next-generation sequencing. Phylogenetic and molecular clock analyses were done to decipher the virus's evolutionary relationships. Comparative analyses of amino acid sequences were performed to determine variations. Protein modeling in Pymol was conducted to elucidate variations in key protein regions. Evolutionary pressure analysis investigated the selection pressures on the virus. In vitro experiments were done to investigate the virus growth kinetics in mammalian Vero E6 and mosquito C6/36 cells. We report the isolation of WN-KOUTV from Salabani in Baringo and Aremet in Isiolo, Kenya. The isolated WN-KOUTVs clustered with previously identified WN-KOUTV strains. Comparative analysis revealed a unique amino acid at NS5 653. The WN-KOUTV lineage as a whole is under purifying selective pressure, with diversifying pressure acting at site NS3 267. The current WN-KOUTV replicated in Vero E6 and C6/36 cells comparable to West Nile virus Lineage 1a, isolated from mosquitoes. Subsequent isolations of WN-KOUTV in phlebotomine sandflies suggest potential vectors, however, vector competence studies would confirm this. Replication in mammalian and insect cell lines suggests there may exist a vector/host relationship. We speculate the close genetic relationship of WN-KOUTV strains from East and West Africa may potentially be enabled by bird migratory routes between the two regions. If proven, this could point to a potential future pandemic pathway for this virus.

Natural Therapy of Cutaneous Leishmaniasis

Leishmaniasis is a parasitic disease that is spread by the bite of phlebotomine sand flies, there are several different forms of leishmaniasis in people, the most common forms is cutaneous leishmaniasis, and visceral leishmaniasis, Cutaneous leishmaniasis is characterized by one or more cutaneous lesions, the sores can change in size and appearance over time, the skin sores of Cutaneous leishmaniasis usually heal on their own, even without treatment, but this can take months or even years. A recent study has lead to new natural treatment to accelerate the healing time of lesions caused by leishmania parasite, which based on using a bandage of banana peels at the lesions site during night for seven to ten days. There were eight cases out of ten had responded positively for using banana peels and completely cured, and two did not respond. Patients who have the injection treatment is healed in short time in compare to one who did not take injection.

Co-Circulation of Leishmania Parasites and Phleboviruses in a Population of Sand Flies Collected in the South of Portugal.

In the Old World, phlebotomine sand flies from the genus Phlebotomus are implicated in the transmission of Leishmania spp. parasites (Kinetoplastida: Trypanosomatidae) and viruses belonging to the genus Phlebovirus (Bunyavirales: Phenuiviridae). Two of the five sand fly species known to occur in Portugal, Phlebotomus perniciosus and Ph. ariasi, the former being the most ubiquitous, are recognized vectors of Leishmania infantum, which causes visceral leishmaniasis, the most prevalent form of leishmaniasis in the country. Phlebotomus perniciosus is also the vector of the neurotropic Toscana virus, which can cause aseptic meningitis. Entomological surveillance is essential to provide fundamental data about the presence of vectors and the pathogens they can carry. As such, and given the lack of data in Portugal, an entomological survey took place in the Algarve, the southernmost region of the country, from May to October 2018. Polymerase chain reaction assays were performed in order to detect the presence of the above-mentioned pathogens in sand fly pools. Not only were both Leishmania parasites and phleboviruses detected during this study, but more importantly, it was the first time their co-circulation was verified in the same sand fly population collected in Portugal.

Nodular pyogranulomatous panniculitis due to Leishmania infantum infection in a domestic ferret (Mustela putorius furo)

Leishmaniosis is a vector-borne disease caused by different Leishmania species and transmitted by phlebotomine sand flies under natural conditions in Europe. Scientific information related to Leishmania infantum in dogs is extensive, where less information is available in cats and other companion animals. Recently, first clinical cases of L.infantum infection in domestic ferrrets (Mustela putorius furo) have been described. However, clinical information on leishmaniosis in this species is limited A 15-month-old male neutered domestic ferret was presented with chronic weight loss and the presence of coalescent, erythematous and firm subcutaneous nodules in the ventral abdominal subcutis. A fine-needle aspiration of these nodules was performed and the cytological examination revealed a granulomatous inflammation with the presence of macrophages contained a number of oval organisms with an eccentric nucleus and pale cytoplasm, compatible with Leishmania spp. amastigotes compatible with Leishmania spp. amastigotes. The nodules were surgically excised and histological examination showed a severe multifocal pyogranulomatous panniculitis. Specific immunohistochemistry and qPCR for L. infantum from excised nodules were positive. Additionally, L. infantum was cultured and isolated from the nodules by a fine-needle aspiration. An in-house Western Blot test for L. infantum was performed in serum sample and a positive result was obtained. This is the first reported case of nodular pyogranulomatous panniculitis due to L. infantum infection in a domestic ferret. Further studies are necessary to determine the relevance of domestic ferrets in the transmission of leishmaniosis. The description of new clinical forms of the disease is important as it can assist veterinarians in identifying these new clinical presentations.

Reconstructing the post-glacial spread of the sand fly Phlebotomus mascittii Grassi, 1908 (Diptera: Psychodidae) in Europe

Phlebotomine sand flies (Diptera: Phlebotominae) are the principal vectors of Leishmania spp. (Kinetoplastida: Trypanosomatidae). In Central Europe, Phlebotomus mascittii is the predominant species, but largely understudied. To better understand factors driving its current distribution, we infer patterns of genetic diversity by testing for signals of population expansion based on two mitochondrial genes and model current and past climate and habitat suitability for seven post-glacial maximum periods, taking 19 climatic variables into account. Consequently, we elucidate their connections by environmental-geographical network analysis. Most analyzed populations share a main haplotype tracing back to a single glacial maximum refuge area on the Mediterranean coasts of South France, which is supported by network analysis. The rapid range expansion of Ph. mascittii likely started in the early mid-Holocene epoch until today and its spread possibly followed two routes. The first one was through northern France to Germany and then Belgium, and the second across the Ligurian coast through present-day Slovenia to Austria, toward the northern Balkans. Here we present a combined approach to reveal glacial refugia and post-glacial spread of Ph. mascittii and observed discrepancies between the modelled and the current known distribution might reveal yet overlooked populations and potential further spread.

Field evaluation of a new suction light trap for the capture of phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae), vectors of leishmaniasis.

Phlebotomine sand flies are crepuscular and nocturnal small dipteran insects in the family Psychodidae. Several disease agents, including Leishmania parasites, are transmitted to humans and other vertebrate hosts by the bite of an infected female sand fly. As part of leishmaniasis surveillance programs, light traps have been routinely used in sand fly collections. In this context, new trapping devices are always being required to improve vector monitoring. Here, the efficiency of a new suction light trap, named Silva suction trap or SS trap, was field evaluated in collecting sand flies. Two SS traps, one with green (520nm, 15,000 mcd) and the other with white (wide spectrum, 18,000 mcd) LEDs, and one CDC-type trap were deployed in a rural forested environment. A total of 4686 phlebotomine sand flies were captured. The most frequent species were females of the Ps. Chagasi series (77.8%) followed by males of Ps. wellcomei (11.6%), Nyssomyia whitmani (3.3%), and Bichromomyia flaviscutellata (2.4%). The CDC-type light trap collected 101.9 ± 20.89 sand flies and 14 species, followed by the white-baited SS trap (87.78 ± 16.36, 14), and the green-baited SS trap (70.61 ± 14.75, 15), but there were no statistically significant differences among traps. A discussion on the considerable advantages of the use of SS traps over CDC traps is included. In this study, the Silva suction trap proved to be efficient and can be an alternative to CDC traps for monitoring adult phlebotomine sand fly populations.

Species identification of phlebotomine sandflies using deep learning and wing interferential pattern (WIP)

Sandflies (Diptera; Psychodidae) are medical and veterinary vectors that transmit diverse parasitic, viral, and bacterial pathogens. Their identification has always been challenging, particularly at the specific and sub-specific levels, because it relies on examining minute and mostly internal structures. Here, to circumvent such limitations, we have evaluated the accuracy and reliability of Wing Interferential Patterns (WIPs) generated on the surface of sandfly wings in conjunction with deep learning (DL) procedures to assign specimens at various taxonomic levels. Our dataset proves that the method can accurately identify sandflies over other dipteran insects at the family, genus, subgenus, and species level with an accuracy higher than 77.0%, regardless of the taxonomic level challenged. This approach does not require inspection of internal organs to address identification, does not rely on identification keys, and can be implemented under field or near-field conditions, showing promise for sandfly pro-active and passive entomological surveys in an era of scarcity in medical entomologists.

A case of visceral leishmaniasis

Leishmaniasis is caused by a protozoa parasite, one of more than 20 Leishmania species, transmitted to humans by the bite of infected female phlebotomine sandflies. More than 90 species of mosquitoes have been identified as carriers of the Leishmania parasite. There are 3 main types of the disease: visceral (often called kala-azar, the most severe form of the disease), cutaneous (the most common), and mucocutaneous. Leishmaniasis is caused by the protozoa parasite Leishmania, which is transmitted by the bite of infected mosquitoes. The disease affects the world's poorest people and is associated with malnutrition, displacement, poor housing conditions, weak immune systems, and lack of resources. Leishmaniasis is related to environmental changes such as deforestation, construction of dams and irrigation systems, and urbanization. An estimated 700,000 to 1 million new infections and 20,000 to 30,000 deaths occur each year. Only a small proportion of people infected with Leishmania parasites will eventually develop the disease.

Genetic Characterization of Sandfly-Borne Viruses in Phlebotomine Sandflies in Iran.

Phleboviruses are classified into two main groups: the sandfly fever group (transmitted by sandflies and mosquitoes) and the Uukuniemi group (transmitted by ticks). Old World sandfly-borne viruses (SBVs) are classified into four main serocomplexes; sandfly fever Naples viruses (SFNVs), sandfly fever Sicilian viruses (SFSVs), Karimabad viruses (KARVs), and Salehabad viruses (SALVs). This study addresses current knowledge gaps on SBVs in Iran by focusing on identification and molecular epidemiology. We used PCR to examine DNA/RNA extracts to identify sandfly species and evaluate for SBV presence. We identified five specimens positive for phleboviruses: one Ph. sergenti for Tehran virus (TEHV), one Ph. papatasi for SFSV, and two Ph. papatasi and one Ph. perfiliewi for KARV. A phylogenetic tree indicated that the TEHV isolate from this study formed a cluster with previous isolates of TEHV, Zerdali virus, and Fermo virus. Meanwhile, the identified SFSV isolate fell in lineage I and was grouped with previous isolates of SFSVs and Dashli virus in Iran. Finally, the KARV isolates from this study formed a monophyletic clade in a sister relationship with other viruses in KARV lineages I and II. This comprehensive study on SBVs in Iran provided new insights into the molecular epidemiology of TEHV, SFSVs and KARVs in this country.

Antiparasitic effect of Farnesol against Leishmania major: A rationale from in vitro and in silico investigations.

Leishmaniasis is a vector-borne parasitic infection caused by the infective bite of female Phlebotomine sandflies. Treatment of leishmaniasis by conventional synthetic compounds is met by challenges pertaining to adverse effects which call for the discovery of newer anti-leishmanial molecules. This study was performed to evaluate the effect and modes of action of a sesquiterpene alcoholic molecule Farnesol on Leishmania major, the causative agent of Zoonotic CL. The cytotoxic effect of Farnesol against L.major promastigotes, amastigotes and macrophages was assessed by MTT test and counting. The IC50 on promastigotes by Farnesol on L.major was also evaluated by flow cytometry. In the findings, promastigotes were reduced at 167μM. The mean numbers of L.major amastigotes in macrophages were significantly decreased on exposure to Farnesol at 172μM. In addition, Farnesol induced significant apoptosis dose-dependent on L.major promastigotes. In silico protein-ligand_binding analyses indicated the effect of Farnesol in perturbation of the ergosterol synthesis pathway of Leishmania with attributes suggesting inhibition of Lanosterol-α-demethylase, the terminal enzyme of ergosterol synthesis machinery. Findings from flow cytometry reveal the role of Farnesol in apoptosis-induced killing in promastigotes. Farnesol was effective at very lower concentrations when compared to Paromomycin. Further studies are crucial to evaluate the therapeutic potential of Farnesol alone or in combination with other conventional drugs in animal models.

Phlebotomine sand flies in rural Mayan communities of Southern Mexico: The heterogeneity of the ruralscape increases the entomological risk

In the Yucatan Peninsula, tropical preserved forests harbor a high diversity of phlebotomine sand fly species, potential vectors of Leishmania. As a result, a significant risk of contracting localized cutaneous leishmaniasis (LCL) is associated with entry into these forest ecosystems. However, with the current trajectory of land use in the region, communities now live within modified landscapes which could increase their risk of contact with vectors. In this study, we characterized the sand fly fauna and its relationship with the characteristics of peridomestic habitats in two rural communities in Yucatan characterized by contrasting records of leishmaniasis. Five human dwellings in each community were randomly selected and the peridomestic landscape was characterized (i.e., type and percentage of land use). For the collection of sand flies, CDC traps were deployed in both the intra and peridomicile. Differences in alpha and beta diversity between communities and ecotopes were estimated considering three separate groups, all species together, zoophilic species, and anthropophilic species. In total, 1, 241 sand flies represented by eight species were collected from November 2021-March 2022. Both communities registered the presence of sand flies in the intra and peridomicile, and females were more abundant than males. However, the greatest diversity of species was recorded in the peridomicile of the community with the highest composition of land uses. Our study demonstrates that the transformation of the forest around the communities favors the abundance and richness of sand flies in the peridomestic environment. We discuss the limitations and implications of our findings regarding the potential risk of the emergence of peri‑rural cycles of leishmaniasis in the region.