Dioclea violacea lectin has potent in vitro leishmanicidal activity against Leishmania infantum via carbohydrate recognition domain.

Despite promising advancements in leishmaniasis treatment, existing therapies often face limitations and significant side effects, stimulating the search for novel therapeutic alternatives. In this context, lectins, such as DVL extracted from Dioclea violacea seeds, have emerged as potential candidates due to their diverse biological activities. This study represents the first investigation of the leishmanicidal potential of DVL in vitro against Leishmania infantum. Our results demonstrate that DVL exhibits a leishmanicidal effect (IC50/24 h = 49.37 µg/mL or 2 µM), binding to glycans on L. infantum. Fluorescence assays revealed that DVL can induce the production of reactive oxygen species (ROS) and cause damage to the parasite's membrane. DVL demonstrated a modulating effect when combined with amphotericin B and glucantime, enhancing the activity of these drugs by 40 % and 80 %, respectively. It also showed no cytotoxicity in Raw 264.7 cells and was able to override the toxic effect of amphotericin B on cells and reduce the survival rate of macrophages infected with amastigote forms, as well as their percentage of infection by 31 %. Therefore, DVL shows promise as a treatment for visceral leishmaniasis caused by L. infantum. Our findings provide valuable insights for future therapeutic development targeting leishmania glycans.

Seasonal dynamics, Leishmania diversity, and nanopore-based metabarcoding of blood meal origins in Culicoides spp. in the newly emerging focus of leishmaniasis in Northern Thailand.

BACKGROUND: Clinical cases of leishmaniasis caused by Leishmania (Mundinia) parasites have been increasingly reported in Southeast Asia, particularly Thailand. Recent evidence has shown that Leishmania (Mundinia) parasites successfully developed into infective metacyclic promastigotes in Culicoides biting midges, strongly supporting their putative role in disease transmission. However, Culicoides diversity, host preference, and Leishmania prevalence in endemic areas remain largely unknown. METHODS: We investigated the seasonal dynamics, infection prevalence, and blood meal identification of Culicoides collected from the emerging focus of visceral leishmaniasis in Lampang Province, Northern Thailand, during 2021-2023. Midge samples were molecularly screened for Leishmania using SSU rRNA-qPCR and ITS1-PCR, followed by Sanger plasmid sequencing, and parasite haplotype diversity was analyzed. Host blood meal origins were comparatively identified using host-specific Cytb-PCRs and a nanopore-based metabarcoding approach. RESULTS: A total of 501 parous and gravid females and 46 blood-engorged ones belonging to at least 17 species of five subgenera (Remmia, Trithecoides, Avaritia, Hoffmania, and Meijerehelea) and two species groups (Shortti and Calvipalpis) were collected with temporal differences in abundance. Leishmania was detected by SSU rRNA-qPCR in 31 samples of at least 11 midge species, consisting of Culicoides oxystoma, C. guttifer, C. orientalis, C. mahasarakhamense, C (Trithecoides) spp., C. innoxius, C. shortti, C. arakawae, C. sumatrae, C. actoni, and C. fulvus, with the overall infection prevalence of 5.7%. The latter six species represent the new records as putative leishmaniasis vectors in Northern Thailand. The ITS1-PCR and plasmid sequencing revealed that Leishmania martiniquensis was predominantly identified in all qPCR-positive species, whereas L. orientalis was identified only in three C. oxystoma samples. The most dominant haplotype of L. martiniquensis in Thailand was genetically intermixed with those from other geographical regions, confirming its globalization. Neutrality test statistics were also significantly negative on regional and country-wide scales, suggesting rapid population expansion or selective sweeps. Nanopore-based blood meal analysis revealed that most Culicoides species are mammalophilic, with peridomestic and wild mammals (cow, pig, deer, and goat-like species) and humans as hosts, while C. guttifer and C. mahasarakhamense fed preferentially on chickens. CONCLUSIONS: This study revealed seasonal dynamics and sympatric circulation of L. martiniquensis and L. orientalis in different species of Culicoides. Evidence of human blood feeding was also demonstrated, implicating Culicoides as putative vectors of human leishmaniasis in endemic areas. Further research is therefore urgently needed to develop vector control strategies and assess the infection status of their reservoir hosts to effectively minimize disease transmission.

Case Notification of Cutaneous Leishmaniasis at Different Elevations in the North-Central Ethiopia from 2018 To 2022.

Background: We aimed to analyze a four-year trend of Cutaneous leishmaniasis (CL) to determine risk levels and hotspots in North-central Ethiopia. Methods: This retrospective study was conducted at Boru Meda Hospital (BMH) from March to April 2023, focusing on CL patients treated at the leishmaniasis treatment center (LTC). Data collected included age, gender, CL type, and other clinical factors. Each patient's origin was traced and geographically mapped by elevation to assess CL risk levels. Results: There were a total of 573 CL patients reported from 46 districts, with a higher number of male patients (n=356) compared to female patients (n=217) (P <0.001). The median age of the patients was 21 years [15-30], with the highest number of CL cases observed among individuals aged 16 to 30 years. The majority of cases (69%) presented with localized CL (LCL). About 39% of patients had a previous treatment history for CL. A significant clustering of CL cases was observed at elevation of 2301-3300 meters above sea level (χ2:17.5; P <0.001), with the highest incidence (case notification) of 14.2/100,000 population. Conclusion: Foci of CL, were burdened at higher elevations and no clinical variation were observed between elevation differences. The majority of cases were concentrated in an area covering approximately 21.4% of the total land mass. CL continues to be a significant issue in North-central Ethiopia and has the potential to spread to new areas.

A New Immunogenic Structure of Polyepitopic Fusion against Leishmania major: In Silico Study.

Background: The lack of complete protection against leishmaniasis and the challenges of anti-leishmaniasis drug treatment have made the treatment process more difficult. This study aimed to develop a new strategy for preparing a vaccine against cutaneous leishmaniasis using some of the antigenic proteins of the Leishmania parasite. Methods: This study was carried out in 2022 at Shahid Chamran University of Ahvaz, Ahvaz, Iran. After preparing suitable epitopes of the Leishmania parasite and examining their antiparasitic properties, the process of making a fusion vaccine was performed and with the help of various bioinformatics tools, physicochemical and structural properties as well as immunological and simulation properties were studied and finally optimized. Construction and cloning were performed in the E.coli K12 system and finally, the docking process was performed with Toll-like receptors (TLRs), major histocompatibility complex I (MHC-I), and MHC-II receptors. With the help of selected epitopes of the Leishmania parasite, which had a high percentage of population coverage, a stable, antigenic, and non-allergenic chimeric vaccine was predicted. Results: The results of the structural analysis of the TLR5\vaccine complex and simulation of its molecular dynamics showed a sufficiently stable binding. It also showed good potential for stimulation and production of active B cells and memory, as well as the potential for CD8+ T, CD4+ T cell production and development of Th2 and Th1-induced immune responses. Conclusion: Computational results showed that the designed immunogenic structure has the potential to adequately stimulate cellular and humoral immune responses against Leishmania parasitic disease. As a result of evaluating the effectiveness of the candidate vaccine through in vivo and in vitro immunological tests, it can be suggested as a vaccine against Leishmania major.

PUF Proteins as Critical RNA-Binding Proteins in TriTryp Parasites: A Review Article.

In eukaryotes, translation is a fundamental step in the long pathway of protein synthesis within the cell. In this process, several proteins and factors have involved directly or indirectly, individually or in association with other elements to contact mRNA. For perfect translation, many essential modifications should be done, such as cis-splicing to remove introns and two main events for capping and poly A polymerization in 5' and 3' end of mRNA, respectively. Gene expression is then regulated at both translation and stability of the target mRNA molecule levels. Pumilio/FBFs (PUFs) are the main group of RNA-binding proteins which bind to the 3'-UTR of target RNA and thereby regulate the fate, stability and subcellular localization of mRNAs and adjust the translated protein level. PUF proteins have been found both in nucleus where that bind to precursor mRNA, for processing and maturation of rRNA, and in cytoplasm where that bind to mRNA, stall the ribosomes, suppress the translation and localization of the mRNA. They can regulate the expression of mRNAs through activation or suppression of translation. Therefore, these proteins have recently garnered much attention as new generation of therapeutic targets against diseases such as cancer and neurological disorders. In comparison to other eukaryotes, trypanosomatids have a high number of PUF proteins, which function not only as gene expression regulatory factors but also in several biological processes such as differentiation and life-cycle progression of the cells. Here, we review the molecular and biological roles of known PUF proteins in TriTryp parasites (Trypanosome brucei, T. cruzi and Leishmania) beside some other parasites.

Bioassay-guided isolation of dehydrocostus lactone from Echinops kebericho as a leishmanicidal drug.

Several strains of Leishmania parasite are involved in the occurrence of leishmaniasis infections, which makes its prevention and treatment very challenging. Currently, all forms of leishmaniasis are being treated with chemical drugs, which have limitations and adverse effects. Discovering antileishmanial agents from natural sources can lead to novel drugs against this dreadful disease. The essential oils and nonpolar solvent extracts of the roots of E. kebericho exhibit antileishmanial activity. Thus, the isolation of the leishmanicidal compounds from the roots of E. kebericho through a bioassay-guided technique was carried out in this study. The present finding showed that the essential oil and hexane fraction of crude extract from the roots of E. kebericho possessed significant leishmanicidal activity against L. major and L. tropica. Dehydrocostus lactone (1), one of the major constituents of the essential oil and hexane fraction, was more active than the standard drug miltefosine against L. major and L. tropica promastigotes. The presence of α-methylene, γ-lactone is the responsible moiety of dehydrocostus lactone towards the leishmanicidal activity against the tested Leishmania species. The MTT assay of dehydrocostus lactone showed inactive toxicity against the human cervical carcinoma HeLa cells. In addition, dehydrocostus lactone exhibits a broad spectrum of antibiotic activities. Based on this interesting finding, dehydrocostus lactone was identified as a potential lead for treating infections caused by Leishmania.

[Prevalence of canine Leishmania infections in Xin'an County, Luoyang City in 2020].

OBJECTIVE: To investigate the prevalence of canine Leishmania infections in villages endemic for visceral leishmaniasis in Xin'an County, Luoyang City, so as to provide insights into visceral leishmaniasis prevention and control. METHODS: All dogs were captured from Huzhanggou Village, Xin'an County, Luoyang City in August 2020, where local cases with visceral leishmaniasis lived. The basic characteristics of dogs were collected, and venous blood was collected via the ear or neck veins of dogs. The serum anti-Leishmania antibody was detected using the rk39 immunochromatographic test and Leishmania nucleic acid was detected using PCR assay, and the prevalence of Leishmania infection was estimated in dogs. RESULTS: A total of 133 domestic dogs were captured from Huzhanggou Village, with a median age of 18.0 (28.5) months. The sero-prevalence of anti-Leishmania antibody was 24.81% (33/133) and the prevalence of a positive PCR assay was 14.29% (19/133) in dogs. The median ages of Leishmania-infected and uninfected dogs were 24.0 (36.0) months and 12.0 (18.0) months, respectively (U = 872.000, P = 0.000), and the prevalence of Leishmania infection was 55.56% (5/9) in "mangy dogs" and 24.19% (30/124) in asymptomatic dogs (χ2 = 2.793, P = 0.095). CONCLUSIONS: There are a large number of asymptomatic dogs with Leishmania infections in Xin'an County, Luoyang City, with a high transmission risk of visceral leishmaniasis. Timely prevention and control measures are required to control the spread of visceral leishmaniasis.

[Risk factors of visceral leishmaniasis in the world: a review].

Visceral leishmaniasis is a zoonotic parasitic disease caused by viscerotropic Leishmania species and transmitted by bites of infected phlebotomine sandflies, which is predominantly prevalent in the Indian subcontinent, eastern Africa and South America. Currently, visceral leishmaniasis is the second most fatal parasitic disease in the world. Because of climate changes, urban development and individual conditions, there are changes in the density of visceral leishmaniasis vector sandflies and the likelihood of contact with humans, resulting in a visceral leishmaniasis transmission risk. The review summarizes natural, social and biological factors affecting the transmission of visceral leishmaniasis, so as to provide insights into formulation of targeted control measures for visceral leishmaniasis.

A Targeted and Protease-Activated Genetically Encoded Melittin-Containing Particle for the Treatment of Cutaneous and Visceral Leishmaniasis.

Intracellular infections are difficult to treat, as pathogens can take advantage of intracellular hiding, evade the immune system, and persist and multiply in host cells. One such intracellular parasite, Leishmania, is the causative agent of leishmaniasis, a neglected tropical disease (NTD), which disproportionately affects the world's most economically disadvantaged. Existing treatments have relied mostly on chemotherapeutic compounds that are becoming increasingly ineffective due to drug resistance, while the development of new therapeutics has been challenging due to the variety of clinical manifestations caused by different Leishmania species. The antimicrobial peptide melittin has been shown to be effective in vitro against a broad spectrum of Leishmania, including species that cause the most common form, cutaneous leishmaniasis, and the most deadly, visceral leishmaniasis. However, melittin's high hemolytic and cytotoxic activity toward host cells has limited its potential for clinical translation. Herein, we report a design strategy for producing a melittin-containing antileishmanial agent that not only enhances melittin's leishmanicidal potency but also abrogates its hemolytic and cytotoxic activity. This therapeutic construct can be directly produced in bacteria, significantly reducing its production cost critical for a NTD therapeutic. The designed melittin-containing fusion crystal incorporates a bioresponsive cathepsin linker that enables it to specifically release melittin in the phagolysosome of infected macrophages. Significantly, this targeted approach has been demonstrated to be efficacious in treating macrophages infected with L. amazonensis and L. donovani in cell-based models and in the corresponding cutaneous and visceral mouse models.

Diversity, vertical stratification and detection of Leishmania DNA in sand flies (Diptera: Psychodidae) collected in the Mapinguari National Park, Brazilian Amazon.

This study aimed to assess the diversity patterns of sand fly fauna across different strata and detect Leishmania DNA in these insects in the Mapinguari National Park in Rondônia and Amazonas states, Northern Brazil. Sand flies were collected with "HP" light traps in the canopy (15 m) and at ground level (1 m) on two trails, during August and November 2021 and March and August 2022. Polymerase chain reaction and DNA sequencing were used to identify Leishmania species. A total of 8,040 individuals (2,303♂ - 28.64 %, 5,737♀ - 71.36 %) were collected and 53 species and 13 genera were identified. The most abundant species were Psychodopygus chagasi (21.00 %), Trichophoromyia ubiquitalis (13.61 %) Psychodopygus davisi (11.69 %), Nyssomyia fraihai (10.58 %), Nyssomyia antunesi (6.68 %) and Nyssomyia richardwardi (5.55 %). Species diversity was greater in the canopy (Shannon index H' = 10.8 common species) when compared to ground level (H' = 10.5 common species). We observed a minimum infection rate of 0.45 % (22/4,868 females), in which Leishmania braziliensis DNA was found in Ps. chagasi and Le. lainsoni DNA in Ps. chagasi, Ny. richardwardi, Ps. ayrozai and Th. ubiquitalis. The minimum infection rate of Leishmania in the canopy was 0.47 % (19/4,031) and in the ground was 0.52 % (3/567). In the present study, we observed Le. lainsoni DNA in females of Ny. richardwardi for the first time. The data presented in this study contribute to understanding sand fly diversity and its distribution between the states of Rondônia and Amazonas. They may be useful for implementing targeted control measures to reduce the spread of leishmaniasis and implement entomological surveillance strategies.

Diagnostic challenges in cutaneous leishmaniasis due to atypical Leishmania infantum: pathologists' insights from re-emergence zones.

Background: Leishmaniasis, a parasitic infection affecting both humans and animals, is increasingly spreading across Mediterranean and European regions, largely driven by human migration and environmental changes. In countries like Türkiye and across Europe, which have seen large influxes of migrants, the incidence of cutaneous leishmaniasis (CL) is rising, with cases now appearing in cities where the disease was previously undocumented. In these previously non-endemic areas, physicians unfamiliar with the characteristic lesions may misdiagnose CL, particularly in cases with only cutaneous manifestations. This study aims to evaluate the impact of re-emerging CL on the routine diagnostic practices of pathologists in Türkiye, by retrospectively reviewing cases. Methods: We conducted a retrospective analysis of CL cases diagnosed between 2013 and 2022 at a single pathology center in Türkiye, covering multiple provinces. Twelve cases of CL were identified and analyzed based on clinical presentation, pre-diagnosis, histopathological findings, and molecular diagnostics. DNA extraction and PCR were performed on paraffin-embedded tissue samples to identify the Leishmania species involved. Results: Out of the twelve CL cases reviewed, seven exhibited morphological findings strongly suggestive of CL (MFSS of CL), warranting further microbiological evaluation. All patients presented with non-healing skin lesions characterized by central ulceration, crater-like formations, or papulonodular lesions. Notably, CL was included in the clinical pre-diagnosis in only 58.3% of cases, while it was not considered in the remaining 41.7% of cases. Clinicians initially pre-diagnosed skin tumors in six cases (50%), four of which led to wide surgical excision. Histopathological examination in all cases revealed chronic or mixed (acute/chronic) inflammation, predominantly rich in histiocytes. To further investigate the role of Leishmania species in the pre-diagnosis, DNA extraction and PCR were performed on paraffin-embedded tissue samples, identifying L. infantum as the causative agent in 10 cases and L. major in two cases. Notably, L. infantum was the causative agent in all five cases initially misdiagnosed as skin tumors, which were also associated with a granulomatous type of chronic inflammation.

Chitosan/collagen biomembrane loaded with 2,3-dihydrobenzofuran for the treatment of cutaneous Leishmaniasis.

In this work, chitosan/collagen-based membranes loaded with 2,3-dihydrobenzofuran (2,3-DHB) were developed through a simple solvent-casting procedure for use in the treatment of cutaneous Leishmaniasis. The obtained membranes were characterized by elemental analysis, FTIR, TG, DSC, and XRD. Porosity, swelling, mechanical properties, hydrophilicity, and antioxidant activity were analyzed. In addition, assessment to the biocompatibility, through fibroblasts/keratinocytes and in vitro wound healing essays were performed. The obtained results show that the new 2,3-DHB loaded chitosan/collagen membrane presented high porosity and swelling capacity as well as maximum strength, hydrophilicity, and antioxidant activity higher in relation to the control. The tests of antileishmanial activity and the AFM images demonstrate great efficacy of inhibition growth of the parasite, superior to those from the standard therapeutic agent that is currently used: Amphotericin B. The new membranes are biocompatible and stimulated the proliferation of keratinocytes. SEM images clearly demonstrate that fibroblasts were able to adhere, maintained their characteristic morphology. The healing test evidenced that the membranes have adequate environment for promoting cell proliferation and growth. As the conventional treatments often use drugs with high toxicity, the as-developed new membranes proved to be excellent candidate to treat cutaneous Leishmaniasis and can be clearly indicated for further advanced studies in vivo.

Fatal case of imported visceral leishmaniasis in a dog caused by Leishmania infantum in French Guiana.

Here we described a case of fatal canine visceral leishmaniasis (VL) in French Guiana, a non-endemic VL Amazonian area. The dog was a 2-year-old pug imported from Brazil to French Guiana. Initially seen for a pruriginous lesion on the muzzle which healed after treatment, the dog was in a deteriorated condition and had sublingual, foreleg and eye ulcers, one month later. A visceral leishmaniasis was suspected by the veterinarian. The dog was hospitalized awaiting results, which revealed the presence of L. infantum. However, the dog succumbed suddenly before the results were returned. Few imported and scarce autochthonous canine VL cases have been previously reported in French Guiana, raising the need for local epidemiological surveillance, considering the possibility of unusual transmission routes of the parasite.

Ties that bind us: Leishmania grasps the sandfly.

The enigmatic haptomonad forms of Leishmania parasites adhere to the sandfly stomodeal valve, damaging this feeding valve and promoting parasite transmission. Yanase et al. recently identified the first parasite proteins involved in adhesion and showed their essentiality in binding to and damaging the valve.

Leishmania infantum exploits the anti-ferroptosis effects of Nrf2 to escape cell death in macrophages.

Macrophages are major host cells for the protozoan Leishmania parasite. Depending on their activation state, they either contribute to the detection and elimination of Leishmania spp. or promote parasite resilience. Here, we report that the activation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in macrophages plays a pivotal role in the progression of Leishmania infantum infection by controlling inflammation and redox balance of macrophages. We also highlight the involvement of the NOX2/reactive oxygen species (ROS) axis in early Nrf2 activation and, subsequently, prostaglandin E2 (PGE2)/EP2r signaling in the sustenance of Nrf2 activation upon infection. Moreover, we establish a ferroptosis-like process within macrophages as a cell death program of L. infantum and the protective effect of Nrf2 in macrophages against L. infantum death. Altogether, these results identify Nrf2 as a critical factor for the susceptibility of L. infantum infection, highlighting Nrf2 as a promising pharmacological target for the development of therapeutic approaches for the treatment of visceral leishmaniasis.

Synthesis and in Vitro Antileishmanial Efficacy of Novel Ethylene Glycol Analogues of Benzothiadiazine-1,1-dioxide.

Leishmaniasis is a vector-borne, parasitic disease affecting millions of people and animals worldwide. Current therapeutic options have proven to be ineffective in both treating the disease and preventing its spread. As a result, new drugs must be developed to effectively combat this disease. In this study, a series of 14 ethylene glycol analogues of benzothiadiazine-1,1-dioxide were synthesised to investigate their antileishmanial potential and cytotoxicity. Analogue 9, 2-(2-phenoxyethyl)-2H-benzo[e][1,2,4]thiadiazine-1,1-dioxide, was identified as the most inhibitory compound as it was observed to moderately inhibit the growth of L. major (IC50 103 µM) and L. donovani (IC50 153 µM) promastigotes. However, in general, the series presented with low biological activity, which may be attributed to reduced target affinity and/or undesired cell culture protein binding.

Immunogenicity and Neutralization Potential of Recombinant Chimeric Protein Comprising the Catalytic Region of Gp63 of Leishmania and LTB against Leishmania Donavani.

AIM: To study the inhibition potential of antibody against a recombinant chimera comprising of the catalytic epitope of gp63 of Leishmania donovani and B subunit of heat-labile enterotoxin [LTB] in the functional activity of L. donovani. BACKGROUND: Visceral leishmaniasis, caused by the protozoan parasite Leishmania donavani, is a major health problem and causes mortality in tropical regions. Protozoan proteases play a crucial role in the pathogenesis of the disease and in establishing infection by countering the host's innate immune responses, namely complement-mediated lysis and phagocytosis. A surface-bound metalloprotease [gp63] has been reported to be a major virulence factor resulting in the evasion of complement- mediated lysis, cleaving host extracellular and intracellular substrates, resulting in intra- phagolysosomal survival Method: The epitope corresponding to the catalytic motif of gp63 of Leishmania donovani has fused with the B subunit of heat-labile enterotoxin, which is known to be immunogenic. The chimera was cloned to a prokaryotic expression vector and purified using Ni NTA affinity chromatography. Antibodies were generated against the purified fusion protein and analyzed for its ability to bind to the gp63 catalytic motif peptide by ELISA. The effect of fusion protein antibody on the functional activity of gp63 was evaluated by assessing the effect of purified IgGs on the protease activity and complement-mediated lysis of L. donovani promastigotes in vitro. RESULTS: The present study reports that a recombinant chimera of the catalytic epitope of gp63 and B subunit of heat-labile enterotoxin [LTB] of E. coli, a potent adjuvant of humoral response can mount significant immune response towards the catalytic epitope. ELISA and Western blot analysis showed that the anti-fusion protein antiserum could recognize the native gp63. Also, it significantly inhibited the protease activity of promastigotes and subsequently increased complement-mediated lysis of the promastigotes in vitro. CONCLUSION: It could be concluded that the hybrid protein containing catalytic motif L. donovani gp63 protein and carrier protein [LTB] could elicit antibodies that could neutralise the functional activity of gp63 and thus could be a potential candidate for subunit leishmaniasis vaccine.

Activation Pathways of Murine Macrophages by Lipophosphoglycan from Strains of Leishmania major (FV1 and LV39).

Lipophosphoglycan (LPG) is an important Leishmania virulence factor. It is the most abundant surface glycoconjugate in promastigotes, playing an important role in the interaction with phagocytic cells. While LPG is known to modulate the macrophage immune response during infection, the activation mechanisms triggered by this glycoconjugate have not been fully elucidated. This work investigated the role that LPGs purified from two strains of Leishmania major (FV1 and LV39) play in macrophage activation, considering the differences in their biochemical structures. Bone marrow-derived macrophages from BALB/c mice were stimulated with 10 µg/mL purified LPG from the LV39 and FV1 strains. We then measured the production of nitric oxide (NO) and cytokines, the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the activation of MAPK pathways. LPG from the LV39 strain, which has longer poly-galactosylated side chains, induced a more pro-inflammatory profile than that from the FV1 strain. This included higher production of NO, TNF-α, and PGE2, and increased expression of COX-2 and iNOS. Additionally, the phosphorylation of ERK-1/2 and JNK was elevated in macrophages exposed to LPG from the LV39 strain. No difference in IL-10 production was observed in cells stimulated by both LPG. Thus, intraspecific structural differences in LPG contribute to distinct innate immune responses in macrophages.

Entomological aspects of leishmaniasis transmission in the urban area of Teófilo Otoni, a municipality endemic for the disease in the Brazilian state of Minas Gerais.

Brazil is endemic for both visceral (VL) and cutaneous (CL) clinical forms of leishmaniasis, poverty-associated diseases with worldwide distribution. Leishmania parasites are the etiological agents of leishmaniases, which are transmitted to humans through the bites of infected phlebotomine sand flies. From 2018 to 2023, 15 cases of VL and 129 cases of CL were reported in Téofilo Otoni, an important economic center in the Brazilian state of Minas Gerais. Owing to the lack of data on the entomological fauna, the present study aimed to clarify this main aspect of leishmaniasis. From May, 2021 to April, 2023, entomological captures were performed monthly in ten neighborhoods in Teófilo Otoni. The influence of bioclimatic variables on insect populations was evaluated, and natural infection by Leishmania spp. was investigated using molecular methods. A total of 306 specimens of 12 species of phlebotomine sand fly were collected. The majority (91.6%) were proven or putative vectors of leishmaniasis agents. The population of insects tended to increase during the cooler and drier months. Although Leishmania infection was not detected in any of the samples, the presence of vectors provides conditions for the maintenance and expansion of the transmission cycle of leishmaniasis in Teófilo Otoni.

Comparison of urine and serum IgG detection ELISA for tegumentary leishmaniasis diagnosis and prognosis.

Laboratorial diagnosis of tegumentary leishmaniasis (TL) is hampered by variable sensitivity and/or specificity of the tests, which are still hampered by blood́ invasive collection. In this context, in the present study, we develop a serum- and urine-based ELISA to TL diagnoses. A recombinant protein (rLiHyA), which was previously showed to be antigenic for the disease, as well as a B-cell epitope produced as synthetic peptide and a Leishmania antigenic extract (SLA), were used as antigens. A total of paired 205 urine and serum samples were used, which were comprised by samples from cutaneous (n = 30) and mucosal (n = 30) leishmaniasis patients, as well as from healthy individuals living in endemic region of disease (n = 45), of patients with Chagas disease (n = 30), leprosy (n = 35), malaria (n = 15) or HIV-infected (n = 20). Results showed that serum-based ELISA presented sensitivity of 24.0 %, 100 % and 41.0 %, when SLA, rLiHyA and synthetic peptide were used as antigens, and specificity of 98.4 %, 98.4 % and 98.4 %, respectively. The area under the curve (AUC) was calculated and results were 0.74, 1.0, and 0.71, respectively, when SLA, rLiHyA and synthetic peptide were used as antigens. Performing an urine-based ELISA, sensitivity was 28.0 %, 100 % and 75.0 %, respectively, when SLA, rLiHyA, and synthetic peptide were used, while specificity values were of 98.4 %, 98.4 % and 98.4 %, respectively. In addition, the AUC values were 0.82, 1.0, and 0.94, respectively. A significant drop in specific antibodies levels in both patients serum and urine samples was found six months after treatment, suggesting a prognostic role of rLiHyA for TL. In conclusion, preliminary data suggest the potential of use patient urine to TL diagnoses.