Associated-risk determinants for anthroponotic cutaneous leishmaniasis treated with meglumine antimoniate: A cohort study in Iran

The developing role of NRF2 and HMOX1 in treatment response of cutaneous leishmaniasis

Anthroponotic cutaneous leishmaniasis (ACL), a neglected parasitic disease, created significant treatment challenges due to rising antimonial resistance, particularly in endemic regions like Iran. This study aimed to investigate the mechanisms behind treatment unresponsiveness in ACL patients. Demographic and clinical characteristics of 21 unresponsive and 10 responsive patients were randomly collected. Leishmania isolates were genotyped using nested polymerase chain reaction (PCR). Real-time PCR assessed the expression levels of two key genes related to treatment unresponsiveness: nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase 1 (HMOX1), along with their associated microRNAs, mir-24a-3p and mir-27b-3p. Gene expression and immunohistochemistry (IHC) assays measured apoptosis activation. Unresponsive patients revealed decreased expression of apoptosis-related genes (Bax, caspase-3, caspase-8) and increased expression of B-cell lymphoma 2 (Bcl2). Furthermore, HMOX1 and NRF2 expression, significant mir-27b-3p upregulation, and mir-24a-3p downregulation were observed in the unresponsive group. These results suggest diminished apoptosis and/or possible potential for chronic progression of Leishmania (L.) tropica infection in unresponsive patients. The increased levels of NRF2 and HMOX1 demonstrate their probable role in drug unresponsiveness. Also, the opposing effects of mir-24a-3p and mir-27b-3p on mentioned genes highlight the necessity for targeted molecular studies to modulate microRNAs expression effectively.

Identification of CβS and ODC antimony resistance markers in anthroponotic cutaneous leishmaniasis field isolates by gene expression profiling

Antiparasitic resistance represents a serious global public health concern with tremendous economic and safety implications. This study intended to investigate the expression of the two major resistant markers: cystathionine β synthase (CβS) and ornithine decarboxylase (ODC) in antimony unresponsive Leishmania tropica isolates compared to responsive ones. Twenty-six patients were randomly selected from widely known foci of anthroponotic cutaneous leishmaniasis in southeastern Iran. Written informed consent of the patients was obtained. Two smears were prepared from the edge of each active lesion; one for microscopic direct smear preparation and the other for inoculation into monophasic NNN media, then for mass production of promastigotes into RPMI-1640 monophasic culture for performing nested PCR and gene expression quantification by real-time PCR. Twenty-six patients consisting of 13 unresponsive and 13 responsive equally distributed among female and male groups. All cases were identified to be L. tropica. Both resistant gene markers were significantly up-regulated in unresponsive and responsive isolates. The findings showed that CβS and ODC are directly linked with the resistance to L. tropica. Alternative drugs or combination therapy and monitoring drug resistance to prevent the spread of resistant isolates are proper strategies to control the disease.

Unlocking Responsive and Unresponsive Signatures: A Transfer Learning Approach for Automated Classification in Cutaneous Leishmaniasis Lesions

Cutaneous leishmaniasis (CL) remains a significant global public health disease, with the critical distinction and exact detection between responsive and unresponsive cases dictating treatment strategies and patient outcomes. However, image-based methods for differentiating these groups are unexplored. This study addresses this gap by developing a deep learning (DL) model utilizing transfer learning to automatically identify responses in CL lesions. A dataset of 102 lesion images (51 per class; equally distributed across train, test, and validation sets) is employed. The DenseNet161, VGG16, and ResNet18 networks, pretrained on a massive image dataset, are fine-tuned for our specific task. The models achieved an accuracy of 76.47%, 73.53%, and 55.88% on the test data, respectively, with a sensitivity of 80%, 75%, and 100% and specificity of 73.68%, 72.22%, and 53.12%, individually. Transfer learning successfully addressed the limited sample size challenge, demonstrating the models' potential for real-world application. This work underscores the significance of automated response detection in CL, paving the way for treatment and improved patient outcomes. While acknowledging limitations like the sample size, the need for collaborative efforts is emphasized to expand datasets and further refine the model. This approach stands as a beacon of hope in the contest against CL, illuminating the path toward a future where data-driven diagnostics guide effective treatment and alleviate the suffering of countless patients. Moreover, the study could be a turning point in eliminating this important global public health and widespread disease.

Preparation, characterization, and in vivo activity of Gossypium hirsutum niosomes against cutaneous leishmaniasis caused by Leishmania major in a murine model: Parasite burden, gene expression, and histopathological profiling

The use of conventional drugs is not a satisfactory treatment for the disease. Therefore, there is a crucial need for alternative therapeutic approaches. This study aimed to investigate the potential anti-leishmanial activity of Gossypium hirsutum niosomes against cutaneous leishmaniasis in a murine model and evaluate their effectiveness by assessing parasite burden, immunomodulatory gene expression, and histopathological profile. We prepared G. hirsutum niosomes and characterized their morphology, size, Fourier transform infrared spectroscopy (FT-IR), and encapsulation efficiency. The in vivo anti-leishmanial activity of the niosomes was evaluated by assessing parasite burden, histopathological profile, and gene expression level. The spleen parasite load in BALB/c mice treated with different groups of G. hirsutum niosomes and G. hirsutum extracts (30%), demonstrated a significant decrease compared to Glucantime®. The least number of leishmanial parasites was observed in H and E-stained histological sections (grade+1), followed by G. hirsutum niosomes or G. hirsutum crude extract (grade+3), Glucantime® (grade+4) and the highest number in the untreated control group (grade+6). There was a substantial difference (P < 0.001) among various treatment groups. Moreover, G. hirsutum niosomes up-regulated the levels of the gene (particularly IFN-γ, P < 0.001) compared to the extract form and Glucantime®. In contrast, IL-4, IL-10, and TNF-β were significantly decreased (P < 0.001) in comparison to untreated control. These results suggest that G. hirsutum niosomes have the potential to be considered a promising alternative therapy for leishmaniasis. Further research is warranted to explore their mechanism of action and optimize their formulation for clinical use.

Global Dilemma and Needs Assessment Toward Achieving Sustainable Development Goals in Controlling Leishmaniasis

Leishmaniasis is a disease of poverty that imposes a devastating medical, social, and economic burden on over 1 billion people nationwide. To date, no in-depth study to analyze the major global challenges and needs assessment has been carried out. This investigation aimed to explore a comprehensive narrative review of leishmaniasis's main challenges and initially highlight obstacles that might impede the implementation of control measures. Also, we propose a specific list of priorities for needs assessment. The presence of socioeconomic factors, multiple clinical and epidemiological forms, various Leishmania species, the complexity of the life cycle, the absence of effective drugs and vaccines, and the lack of efficient vector and reservoir control make this organism unique and sophisticated in playing a tangled role to react tricky with its surrounding environments, despite extensive efforts and implementation of all-inclusive former control measures. These facts indicate that the previous strategic plans, financial support, and basic infrastructures connected to leishmaniasis surveillance are still insufficient. Strengthening the leishmaniasis framework in a context of accelerated programmatic action and intensification of cross-cutting activities along with other neglected tropical diseases (NTDs) is confidently expected to result in greater effectiveness, cost-benefit, and fruitful management. Sensitive diagnostics, effective therapeutics, and efficacious vaccines are vital to accelerating advancement toward elimination, and reducing morbidity/mortality and program costs. Collective actions devoted by all sectors and policy-makers can hopefully overcome technical and operational barriers to guarantee that effective and coordinated implementation plans are sustained to meet the road map for NTDs 2021- 2030 goals.

Cutaneous Leishmaniasis Hampers COVID-19: A Controlled Cross-Sectional Study in High-Burden Endemic Areas of Iran

INTRODUCTION

Emerging infectious diseases such as SARS-CoV-2 can cause pandemics and create a critical risk for humans. In a previous pilot study, we reported that the immunological responses induced by cutaneous leishmaniasis (CL) could decrease the incidence and severity of COVID-19. In this large-scale case-control study, we assessed the possible relationship between mortality and morbidity of COVID-19 in healed CL persons suffering scars compared to cases without CL history.

METHODS

This controlled cross-sectional study was conducted between July 2020 and December 2022 in the endemic and high-burden areas of CL in southeastern Iran. In the study, 1400 previous CL cases with scars and 1,521,329 subjects who had no previous CL were analyzed. We used R 4.0.2 to analyze the data. Firth's bias reduction approach corresponding to the penalization of likelihood logistic regression by Jeffreys was also employed to influence the variables in the dataset. Also, a Bayesian ordinal logistic regression model was performed to explore the COVID-19 severity in both case and referent groups.

RESULTS

The occurrence and severity rate of COVID-19 in CL scar cases are significantly less than in the non-CL control group, while in the CL scar subjects, patients with critical conditions and mortality were not observed. The morbidity (OR = 0.11, CI 0.06-0.20 and P < 0.001) and severity of COVID-19 in previous cases with CL scars were significantly diminished than that in the control group (credible interval - 2.57, - 1.62).

CONCLUSIONS

The results represented a durable negative relationship between cured CL and COVID-19 incidence and severity. Additional studies seem necessary and should be designed to further validate the true impact and underlying mechanistic action of CL on COVID-19.

Genetic Diversity of Leishmania major Isolated from Different Dermal Lesions Using ITS2 Region

BACKGROUND AND OBJECTIVE

Cutaneous leishmaniasis (CL) is still considered to be an uncontrolled endemic disease that spreads in many countries. The current study aimed to determine intra-species relationships of L. major using ITS2 sequencing.

METHODS

The study was conducted from the beginning of March to the end of November 2022. All medical information regarding CL was collected from patients of Thi-Qar province who attended the Dermatology Department of Al-Hussein Teaching Hospital in Nasiriyah city. Seventy-three samples were selected for the molecular identification after confirming microscopy with Giemsa stain. In this study, the primers were designed using NCBI GenBank sequence database and Primer 3 plus primer design online software.

RESULTS

The results recorded 21 (28.77%) positive samples of L. major using the internal transcribed spacer 2 region (ITS2) in ribosomal RNA gene. The local L. major IQN.1-IQN.10 were submitted to NCBI GenBank database with accession numbers OM069357.1-OM069366.1, respectively. The phylogenetic analysis revealed that local isolates of L. major showed a close relationship with NCBI-BLAST L. major Iran isolate (KU680848.1).

CONCLUSION

ITS2-PCR is suitable for identifying Leishmania spp. and determining genetic diversity. A phylogenetic data analysis may provide an idea on the genetic homogeneity of local isolates and knowing the genetic origin of the dermal lesion. However, the local isolates showed genetic proximity to the KU680848.1 isolate. This signifies the possibility of infection prevalence from Iranian areas. In general, genetic variation of L. major isolates may give several clinical manifestations of the cutaneous lesion. Therefore, determination of the heterogeneity is important for detecting the infection origin, epidemiology, therapy, and control strategies.

A prospective longitudinal study on the elimination trend of rural cutaneous leishmaniasis in southeastern Iran: Climate change, population displacement, and agricultural transition from 1991 to 2021

Leishmaniasis is a complex disease. Any change in weather conditions affects the humans' social and agricultural expansion and, consequently, the parasite's life cycle in terms of ecology, biodiversity, social stigma, and exclusion. This population-based prospective longitudinal investigation was conducted between 1991 and 2021 in a well-defined CL (cutaneous leishmaniasis) focus in Bam County, southeastern Iran. A robust health clinic and health surveillance system were responsible for the ongoing systematic documentation, detection, identification, and management of CL cases. The exponential smoothing method via the state space model was used in the univariate time series. The TTR, smooth, and forecast packages were used in R software. Landsat satellite images from 1991, 2001, 2011, and 2021 were employed in the physical development. During this period, the temperature increased while the rainfall and humidity decreased. The findings showed a downward trend in the standardized drought index. Also, the results showed that climate warming and ecological changes profoundly affected the area's agricultural patterns and topographical features. Furthermore, the last three decades witnessed an elimination trend for zoonotic CL (ZCL) and the predominance of anthroponotic CL (ACL). The present findings showed that the critical factors in the predominance of ACL and elimination of ZCL were rising temperature, drought, migration, unplanned urbanization, earthquake, and agrarian reform. The wall-enclosed palm tree gardens excluded the primary ZCL reservoir host. They controlled the disease while providing suitable conditions for the emergence/re-emergence of ACL in the newly established settlements and the unplanned ecozone. Therefore, robust health infrastructures, sustained financial support, and evidence-based research studies are crucial to facilitating the necessary surveillance, monitoring, and evaluation to control and eliminate the disease.

Mutual Role of Patients and the Healthcare System in the Control of Cutaneous Leishmaniasis

Leishmaniasis is a neglected and old emerging/reemerging disease that has extremely increased and expanded in the different geographical areas. Cutaneous leishmaniasis (CL) is a common global public health concern in the tropics and subtropics reported from the Eastern Mediterranean Region, Africa, Latin America, and the Indian subcontinent. The presence of numerous epidemiological and clinical characteristics of the disease present a challenge in managing and controlling it. Despite wonderful efforts to control the disease in endemic areas, it appears that the burden of CL is still high. There is no comprehensive survey considering the interactive role of patients and medical services in the international CL control system. In the present study, the effective and mutual responsibility of the patients and the healthcare management in controlling the CL are reviewed, described, and discussed. Some patient-related factors that have a remarkable impact on the proper treatment and control strategies are low-socioeconomic condition, lack of sufficient knowledge about the disease, absence of personal protection, disregarding adherence to treatment, culture and incorrect beliefs about disease and therapy, depression, and lack of appropriate support from the family. On the other hand, some healthcare system-related factors that have an important effect on the suitable therapy and management of the disease are the economic burden of healthcare and drug preparation, unsuitable follow-up assessments, health education, early detection, and the right treatment, handling of unresponsive cases, active case detection, and monitoring/evaluation. Improving the socioeconomic conditions and living standards supports longstanding elimination approaches, and facilitates the wide-ranging control of the disease. Trained health staff and experienced clinicians should strengthen the building capacity for appropriate control programs throughout the healthcare system. These measures need sustained encouragement and appropriate multifunctional activities through all government segments including policymakers, the health system, clinical physicians, researchers, and also the private sector. In a suitable strategy, it is essential to understand precisely all the aspects of control strategies to respond correctly to the requests. Nevertheless, due to the complexity of the causative agent, major challenges/gaps remain, and vigorous conservative control plans should be continued until novel tools become available.

Antileishmanial effects and drugability characteristics of a heterocyclic copper complex: An in silico, in vitro and molecular study

Leishmaniasis caused by the protozoan Leishmania presents a severe illness, principally in tropical and subtropical areas. Antileishmanial metal complexes, like Glucantime®️ with proven activity, are routinely studied to probe their potency. We investigated the effects of a Cu (II) homoleptic complex coordinated by two dimethyl-bipyridine ligands against Leishmania major stages in silico and in vitro. The affinity of this heterocyclic Cu (II) complex (CuDMBP) towards a parasitic metacaspase was studied by molecular docking. Key pharmacokinetic and pharmacodynamic properties of the complex were predicted using three web-based tools. CuDMBP was tested for in vitro antileishmanial activities using MTT assay, model murine macrophages, flow cytometry, and quantitative real-time polymerase chain reaction (qPCR). Molecular docking confirmed the tendency between the target macromolecule and the complex. ADMET evaluations highlighted CuDMBP's key pharmacological features, including P-glycoprotein-associated GI absorption and lack of trans-BBB permeability. MTT showed significant inhibitory effects against promastigotes. CuDMBP significantly increased the level of cellular IL-12 expression (p < 0.05), while the upregulation observed in the expression of iNOS was considered not significant (p > 0.05). It decreased the expression of IL-10 significantly (p < 0.05). Findings demonstrated that CuDMBP deserves to be introduced as a leishmanicidal candidate provided further studies are carried out.

Cutaneous leishmaniasis situation analysis in the Islamic Republic of Iran in preparation for an elimination plan

Iran has invariably been under the growing public health threat of cutaneous leishmaniasis (CL), a significant barrier to local development that hinders the prevention and control efforts toward eliminating the disease. So far, no comprehensive and in-depth epidemiological analysis of the CL situation has been carried out nationwide. This study aimed to employ advanced statistical models to analyze the data collected through the Center for Diseases Control and Prevention of Communicable Diseases during 1989-2020. However, we emphasized the current trends, 2013-2020, to study temporal and spatial CL patterns. In the country, the epidemiology of CL is incredibly intricate due to various factors. This fact indicates that the basic infrastructure, the preceding supports, and the implementation plan related to preventive and therapeutic measures need crucial support. The leishmaniasis situation analysis is consistent with desperate requirements for efficient information on the control program in the area. This review provides evidence of temporally regressive and spatially expanding incidence of CL with characteristic geographical patterns and disease hotspots, signifying an urgent need for comprehensive control strategies. This information could be a suitable model and practical experience in the Eastern Mediterranean Region, where over 80% of CL is reported.

Poor adherence is a major barrier to the proper treatment of cutaneous leishmaniasis: A case-control field assessment in Iran

Leishmaniasis is an overlooked, poverty-stricken, and complex disease with growing social and public health problems. In general, leishmaniasis is a curable disease; however, there is an expansion of unresponsive cases to treatment in cutaneous leishmaniasis (CL). One of the effective and ignored determinants in the treatment outcome of CL is poor treatment adherence (PTA). PTA is an overlooked and widespread phenomenon to proper Leishmania treatment. This study aimed to explore the effect of poor adherence in unresponsiveness to treatment in patients with anthroponotic CL (ACL) by comparing conventional statistical modalities and machine learning analyses in Iran. Overall, 190 cases consisting of 50 unresponsive patients (case group), and 140 responsive patients (control group) with ACL were randomly selected. The data collecting form that included 25 queries (Q) was recorded for each case and analyzed by R software and genetic algorithm (GA) approaches. Complex treatment regimens (Q11), cultural and lay views about the disease and therapy (Q8), life stress, hopelessness and negative feelings (Q22), adverse effects of treatment (Q13), and long duration of the lesion (Q12) were the most prevalent significant variables that inhibited effective treatment adherence by the two methods, in decreasing order of significance. In the inherent algorithm approach, similar to the statistical approach, the most significant feature was complex treatment regimens (Q11). Providing essential knowledge about ACL and treatment of patients with chronic diseases and patients with misconceptions about chemical drugs are important issues directly related to the disease's unresponsiveness. Furthermore, early detection of patients to prevent the long duration of the disease and the process of treatment, efforts to minimize side effects of treatment, induction of positive thinking, and giving hope to patients with stress and anxiety by medical staff, and family can help patients adhere to the treatment.

Prophylactic effect of cutaneous leishmaniasis against COVID-19: a case-control field assessment

INTRODUCTION

We assessed the potential relationship between COVID-19 and laboratory-confirmed cutaneous leishmaniasis (CL)-registered cases with a history of scarring, compared with volunteer participants without history of CL.

METHODS

This case-control retrospective study was conducted in southeastern Iran with a high anthroponotic cutaneous leishmaniasis (ACL) burden.

RESULTS

Overall, n=1010 CL cases (n=479 male, n=531 female) were evaluated for infection with SARS-CoV-2. In the CL case group, 2 men and 1 woman (0.3% in total) had a mild form of COVID-19 disease; none were hospitalized or died. In contrast, of n=2020 participants without history of CL, n=57 (2.9%) contracted laboratory-confirmed COVID-19, including mild (66.7%), hospitalized (26.3%), critical (3.5%) and fatal (3.5%). There was a strong negative association between CL infection and COVID-19. The burden of COVID-19 in CL-cured participants significantly reduced the morbidity (odds ratio: 0.12; CI: 0.03-0.30; P <0.001) and mortality (percentile: -4.10, -0.02).

CONCLUSION

Participants with a history of CL scar had significantly reduced incidence of COVID-19 morbidity and mortality. The cross-protection mediated by CL may retard COVID-19 in endemic countries. However, further longitudinal studies are needed to explore the potential profile and duration of this protection offered by CL against COVID-19.

Global distribution of treatment resistance gene markers for leishmaniasis

BACKGROUND

Pentavalent antimonials (Sb(V)) such as meglumine antimoniate (Glucantime®) and sodium stibogluconate (Pentostam®) are used as first-line treatments for leishmaniasis, either alone or in combination with second-line drugs such as amphotericin B (Amp B), miltefosine (MIL), methotrexate (MTX), or cryotherapy. Therapeutic aspects of these drugs are now challenged because of clinical resistance worldwide.

METHODS

We reviewedthe recent original studies were assessed by searching in electronic databases such as Scopus, Pubmed, Embase, and Web of Science.

RESULTS

Studies on molecular biomarkers involved in drug resistance are essential for monitoring the disease. We reviewed genes and mechanisms of resistance to leishmaniasis, and the geographical distribution of these biomarkers in each country has also been thoroughly investigated.

CONCLUSION

Due to the emergence of resistant genes mainly in anthroponotic Leishmania species such as L. donovani and L. tropica, as the causative agents of ACL and AVL, respectively, selection of an appropriate treatment modality is essential. Physicians should be aware of the presence of such resistance for the selection of proper treatment modalities in endemic countries.

Fifty years of struggle to control cutaneous leishmaniasis in the highest endemic county in Iran: A longitudinal observation inferred with interrupted time series model

Negligible data are available following major social activities and environmental changes on leishmaniasis. Therefore, how interactions between these events influence cutaneous leishmaniasis (CL) risk is not well-known. This longitudinal study was undertaken to explore the impact of interventions conducted between 1971 and 2020 in Bam county, which has had the highest disease burden in Iran. Only confirmed CL cases during this period were taken into account. Data were analyzed by SPSS 22 using the X² test to assess the significance of the difference between proportions. Moreover, we used interrupted time series (ITS) to assess the impact of three environmental events during this period. Overall, 40,164 cases of CL occurred in the past five decades. Multiple complex factors were among the leading causes that synergistically induced the emergence/re-emergence of CL outbreaks in Bam. The main factors attributed negatively to CL control were cessation of malaria spraying activity, expansion of the city spaces, and a massive earthquake creating new breeding potentials for the vectors. The highest impact on CL incidence during these years was related to the earthquake [coefficient = 17.8 (95% CI: 11.3, 22.7); p-value < 0.001]. Many factors can contribute to CL outbreaks in endemic foci. They also can cause new foci in new areas. Since humans are the single reservoir for CL in this area, early detection and effective management significantly contribute to controlling CL to reduce the disease burden. However, essential evidence gaps remain, and new tools are crucial before the disease can ultimately be controlled. Nevertheless, sustained funding and more trained task forces are essential to strengthen surveillance and case management and monitor the interventions’ impact.

We aimed to conduct this longitudinal observation to assess the impact of interventions applied between 1971 and 2020 in Bam county, Iran’s highest anthroponotic cutaneous leishmaniasis burden. Only confirmed CL cases were taken into account. Overall, 40,164 cases of CL occurred in the past five decades. Multiple complex factors were among the leading causes that synergistically induced the emergence/re-emergence of CL outbreaks in Bam. The main factors attributed negatively to CL control were cessation of malaria spraying activity, expansion of the city spaces, and a massive earthquake creating new breeding potentials for the vectors. Since humans are the single reservoir host for CL in this area, early detection and effective management significantly contribute to controlling CL to reduce the disease burden. However, continuous funding and more trained forces are critical to strengthening surveillance and case management and monitoring the interventions’ impact.

The Fraction of the Snake Venom, Its Leishmanicidal Effect, and the Stimulation of an Anti-Leishmania Response in Infected Macrophages

BACKGROUND AND AIMS

Due to the lack of an effective vaccine and complexity of the control measures against vectors and reservoir hosts, the control of leishmaniasis depends primarily on chemotherapy. This study was aimed to assess the snake venom, Naja naja oxiana fraction 11(NNOVF11) on Leishmania infantum and its broad mode of action.

METHODS

A wide range of in vitro advanced assays including high-performance liquid chromatography (HPLC), MTT (3-[4, 5-Dimethylthiazol-2-yl]-2, 5diphenyltetrazolium bromide; Thiazolyl blue), macrophage assays, quantitative real-time polymerase chain reaction (qPCR), flow cytometry and enzyme- linked immunosorbent assay (ELISA) on L. infantum promastigote and amastigote stages were used. IC₅₀ values of L. infantum stages, CC₅₀ value, and apoptosis were also analyzed.

RESULTS

The NNOV-F11 demonstrated strong antileishmanial activity against L. infantum stages in a dose-dependent manner compared to the untreated control group. Interleukin (IL)-12, TNF-α, and iNOS genes expression as the indicators of T helper(h)1 response significantly increased; in contrast, the expression level of IL-10, as the representative of Th2 response significantly decreased (p < 0.001). Reactive oxygen species (ROS) detection showed a significant increase (p < 0.001) after treatment with different concentrations of NNOV-F11, unlike arginase (ARG) activity, which displayed a significant reduction (p < 0.001).

CONCLUSION

NNOV-F11 possessed a potent inhibitory effect on L. infantum stages with the multifunctional and broad mode of actions, which promoted the immunomodulatory role, induced ROS production, stimulated apoptotic-like mechanisms, and inhibited L-ARG activity, which collectively led to the parasite death. Further studies are crucial to assess the effect of the NNOV-F11 on animal models or clinical settings.

Leishmanicidal potentials of Gossypium hirsutum extract and its fractions on Leishmania major in a murine model: parasite burden, gene expression, and histopathological profile

Introduction. Leishmaniasis is a neglected tropical and subtropical disease caused by over 20 protozoan species.Hypothesis. Treatment of this complex disease with traditional synthetic drugs is a major challenge worldwide. Natural constituents are unique candidates for future therapeutic development.Aim. This study aimed to assess the in vivo anti-leishmanial effect of the Gossypium hirsutum extract, and its fractions compared to the standard drug (Glucantime, MA) in a murine model and explore the mechanism of action.Methodology. Footpads of BALB/c mice were infected with stationary phase promastigotes and treated topically and intraperitoneally with G. hirsutum extract, its fractions, or Glucantime, 4 weeks post-infection. The extract and fractions were prepared using the Soxhlet apparatus with chloroform followed by the column procedure.Results. The crude extract significantly decreased the footpad parasite load and lesion size compared to the untreated control group (P<0.05), as revealed by dilution assay, quantitative real-time PCR, and histopathological analyses. The primary mode of action involved an immunomodulatory role towards the Th1 response in the up-regulation of IFN-γ and IL-12 and the suppression of IL-10 gene expression profiling against cutaneous leishmaniasis caused by Leishmania major.Conclusion. This finding suggests that the extract possesses multiple combinatory effects of diverse bioactive phytochemical compositions that exert its mechanisms of action through agonistic-synergistic interactions. The topical extract formulation could be a suitable and unique candidate for future investigation and pharmacological development. Further studies are crucial to evaluate the therapeutic potentials of the extract alone and in combination with conventional drugs using clinical settings.

Determinants of Unresponsiveness to Treatment in Cutaneous Leishmaniasis: A Focus on Anthroponotic Form Due to Leishmania tropica

Cutaneous leishmaniasis (CL) is a curable disease; however, due to various risk factors, unresponsiveness to CL treatments is inevitable. The treatment of CL has been firmly correlated with multiple determinants, such as demographical, clinical, and environmental factors, the host’s immune response, poor treatment adherence, the parasite’s genetic make-up, and Leishmania RNA virus. This study primarily focuses on the risk factors associated with different therapeutic outcomes following meglumine antimoniate (MA; Glucantime^®) treatment and policy approaches to prevent unresponsiveness in CL patients with a focus on anthroponotic form (ACL). Findings suggest that effective preventive and therapeutic measures should be more vigorously implemented, particularly in endemic areas. Accordingly, extensive training is essential to monitor drug unresponsiveness regularly, especially in tropical regions where the disease is prevalent. Since humans are the fundamental reservoir host of ACL due to L. tropica, prompt detection, early diagnosis, and timely and effective treatment could help control this disease. Furthermore, major challenges and gaps remain: efficacious vaccine, new tools, and expert staff are crucial before CL can be definitively controlled.

The Effect of Naja naja oxiana Snake Venom Against Leishmania tropica Confirmed by Advanced Assays

PURPOSE

The aim of this study was to explore the activity of Naja naja oxiana venom on Leishmania tropica and its modes of action.

METHODS

Different fractions of Naja naja oxiana venom (NNOV) were prepared and characterized by high-performance liquid chromatography. The superior component, fraction k (FK) was selected. The activity of the fraction was assessed using advanced assays.

RESULTS

Interleukin (IL)-12, TNF-α and iNOS gene expression as the indicators of Th1 significantly increased. In contrast, the level of IL-10, as the marker of T helper 2 substantially decreased (p < 0.001). Reactive oxygen species (ROS) detection showed a significant increase (p < 0.001) after treatment with different concentrations of NNOV-FK, unlike arginase (L-ARG) activity which showed a significant reduction (p < 0.001). The NNOV-FK showed significant lethal activity on the L. tropica stages.

CONCLUSION

The findings demonstrated that NNOV-FK represented a strong leishmanicidal activity on L. tropica stages. The major modes of NNOV-FK action are multidimensional, which perceives the induction of a synergistic response and upregulation of the immune-modulatory role towards Th1 response against L. tropica stages as well as apoptotic and anti-metabolic action as a model drug to generate ROS, block the polyamine synthesis and lead to parasite death.

A novel diagnostic and prognostic approach for unresponsive patients with anthroponotic cutaneous leishmaniasis using artificial neural networks

Cutaneous leishmaniasis (CL) imposes a major health burden throughout the tropical and subtropical regions of the globe. Unresponsive cases are common phenomena occurred upon exposure to the standard drugs. Therefore, rapid detection, prognosis and classification of the disease are crucial for selecting the proper treatment modality. Using machine learning (ML) techniques, this study aimed to detect unresponsive cases of ACL, caused by Leishmania tropica, which will consequently be used for a more effective treatment modality. This study was conducted as a case-control setting. Patients were selected in a major ACL focus from both unresponsive and responsive cases. Nine unique and relevant features of patients with ACL were selected. To categorize the patients, different classifier models such as k-nearest neighbors (KNN), support vector machines (SVM), multilayer perceptron (MLP), learning vector quantization (LVQ) and multipass LVQ were applied and compared for this supervised learning task. Comparison of the receiver operating characteristic graphs (ROC) and confusion plots for the above models represented that MLP was a fairly accurate prediction model to solve this problem. The overall accuracy in terms of sensitivity, specificity and area under ROC curve (AUC) of MLP classifier were 87.8%, 90.3%, 86% and 0.88%, respectively. Moreover, the duration of the skin lesion was the most influential feature in MLP classifier, while gender was the least. The present investigation demonstrated that MLP model could be utilized for rapid detection, accurate prognosis and effective treatment of unresponsive patients with ACL. The results showed that the major feature affecting the responsiveness to treatments is the duration of the lesion. This novel approach is unique and can be beneficial in developing diagnostic, prophylactic and therapeutic measures against the disease. This attempt could be a preliminary step towards the expansion of ML application in future directions.

Magnetic cobalt oxide nanosheets: green synthesis and in vitro cytotoxicity

Cobalt oxide nanoparticles were prepared via green chemistry route and fully characterized by Field Emission Scanning Electron Microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM) analyses; the CoO and Co₃O₄ nanoparticles, in sheet-shaped cobalt oxide form, ensued simultaneously in one step. The varying concentrations of NPs were analyzed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test on the cancer cell line (U87) which revealed that with increasing concentration of cobalt oxide nanoparticles, the survival rate of U87 tumor cells decreases; IC₅₀ of nanoparticles being ~ 55 µg/ml^-1.

The potential therapeutic role of PTR1 gene in non-healing anthroponotic cutaneous leishmaniasis due to Leishmania tropica

BACKGROUND

Drug resistance is a common phenomenon frequently observed in countries where leishmaniasis is endemic. Due to the production of the pteridine reductase enzyme (PTR1), drugs lose their efficacy, and consequently, the patient becomes unresponsive to treatment. This study aimed to compare the in vitro effect of meglumine antimoniate (MA) on non- healing Leishmania tropica isolates and on MA transfected non-healing one to PTR1.

METHODS

Two non-healing and one healing isolates of L. tropica were collected from patients who received two courses or one cycle of intralesional MA along with biweekly liquid nitrogen cryotherapy or systemic treatment alone, respectively. After confirmation of L. tropica isolates by polymerase chain reaction (PCR), the recombinant plasmid pcDNA-rPTR (antisense) was transfected via electroporation and cultured on M199. Isolates in form of promastigotes were treated with different concentrations of MA and read using an enzyme-linked immunosorbent assay (ELISA) reader and the half inhibitory concentration (IC50 ) value was calculated. The amastigotes were grown in mouse macrophages and were similarly treated with various concentrations of MA. The culture glass slides were stained, and the mean number of intramacrophage amastigotes and infected macrophages were assessed in triplicate for both stages.

RESULTS

All three transfected isolates displayed a reduction in optical density compared with the promastigotes in respective isolates, although there was no significant difference between non-healing and healing isolates. In contrast, in the clinical form (amastigotes), there was a significant difference between non-healing and healing isolates (p < 0.05).

CONCLUSION

The results indicated that the PTR1 gene reduced the efficacy of the drug, and its inhibition by antisense and could improve the treatment of non-healing cases. These findings have future implications in the prophylactic and therapeutic modality of non- healing Leishmania isolates to drug.

A long-lasting emerging epidemic of anthroponotic cutaneous leishmaniasis in southeastern Iran: population movement and peri-urban settlements as a major risk factor

Background

Epidemics of cutaneous leishmaniasis (CL) are occurring more frequently and spreading faster and farther than before in many areas of the world. The present study aimed to assess a long-lasting emerging epidemic (2005–2019) of 5532 cases with anthroponotic CL (ACL) in peri-urban areas of Kerman city in southeastern Iran.

Methods

This descriptive-analytical study was carried out for 15 years in Kerman province, southeastern Iran. The data were passively obtained through the health surveillance system and the Kerman Leishmaniasis Research Center. Every subject was diagnosed using direct smear microscopy. The representative causative agent was further examined by ITS1-PCR, PCR-RFLP, 7SL RNA gene sequencing and phylogenetic analyses. For each subject, a case report form designating demographic and clinical data was recorded.

Results

A different pattern of ACL incidence was found in peri-urban areas compared to that in the city of Kerman. The incidence rate of ACL cases has significantly increased (P < 0.001) from 2005 to 2016 in new settlements with a gradual decline after that. The overall average risk of contracting the disease was 7.6 times higher in peri-urban areas compared to Kerman city, an old endemic focus. All isolates consisting of six variants were confirmed to be Leishmania tropica. The overall pattern of the ACL infection indicates that the etiological agent of ACL is propagated and transmitted by the bite of female Phlebotomus sergenti sandflies from person to person from dissimilar clones as reflected by the complexity of the migrants’ backgrounds in the province.

Conclusions

The movement of populations and establishment of new settlements in peri-urban areas close to endemic areas are major risk factors for and are directly linked to CL. The underlying factors of this emerging ACL epidemic caused by L. tropica were disasters and droughts, among others. A robust commitment to a multilateral approach is crucial to make improvements in this area. This will require decisive coordinated actions through all governmental factions and non-governmental organizations. Furthermore, active and passive case detection strategies, early diagnosis, and effective treatment could help control the disease.

Reemergence of zoonotic cutaneous leishmaniasis in an endemic focus, northeastern Iran

Zoonotic cutaneous leishmaniasis (ZCL) is a form of disease, which is mostly caused by Leishmania major (L.major) in the Old World with high incidence through early life. Recently, the high incidence of CL has been reported in Jajarm County, northeastern Iran. The aim of the present study was to investigate the epidemiological aspects of CL and to identify Leishmania spp. in the area. Between 2012 and 2018, patients with active lesions suspected of CL were examined. Diagnosis was performed by methods of clinical examination and direct smears. Conventional kDNA polymerase chain reaction (PCR) was used to identify species of Leishmania. During the seven-year study period, 629 subjects were diagnosed as CL cases by clinical and microscopic examination. Considering the population of the study area, the average incidence rate was 237.8 per 100,000 population. Most (29.4%) of the subjects with ZCL were aged <10 years. Most of the patients (58.7%) were male and the rest were female. Most ulcers were observed on the face (32.2%) and hands (23.7%), respectively. Most patients (90%) had two or more ulcers on their body. The highest incidence was in the autumn in October (32%). Our data revealed that an ongoing reemergence of ZCL focus caused by L.major has arisen in the study area. Moreover, direct PCR on the smears for identifying Leishmania showed 100% specificity, and the species was identified as L. major using species -specific kDNA PCR. The use of conventional PCR on skin smears seems to provide a valuable method for confirming the clinical diagnosis of ZCL, which is very specific and sensitive particularly for clinical correlative studies. Further investigations are needed to improve planning strategies of vectors and reservoirs populations.

Major risk factors and histopathological profile of treatment failure, relapse and chronic patients with anthroponotic cutaneous leishmaniasis: A prospective case-control study on treatment outcome and their medical importance

Over the last years, there has been a remarkable increase in the number of unresponsive patients with anthroponotic cutaneous leishmaniasis (ACL) reported worldwide. The primary objective of this study was to explore the role of demographic, clinical and environmental risk related-factors in the development of treatment failure, relapse and chronic cases compared to responsive patients with ACL. Moreover, molecular, histopathological and immunohistochemical (IHC) findings between these forms were explored. This work was undertaken as a prospective and case-control study in southeastern Iran. Culture media and nested PCR were used to identify the causative agent. Univariate multinomial and multiple multinomial logistic regression models and the backward elimination stepwise method were applied to analyze the data. A P<0.05 was defined as significant. Also, for different groups, skin punch biopsies were used to study the histopathological and immunohistochemical (IHC) profile. All samples showed that L. tropica was the only etiological agent in all unresponsive and responsive patients with ACL. Data analysis represented that 8 major risk factors including nationality, age groups, occupation, marital status, history of chronic diseases, duration of the lesion, the lesion on face and presence of domestic animals in the house were significantly associated with the induction of unresponsive forms. The histopathological and immunohistochemical findings were different from one form to another. The present findings clearly demonstrated a positive relation between ACL and distinct demographic, clinical and environmental risk determinants. Knowledge of the main risk factors for ACL infection is crucial in improving clinical and public health strategies and monitor such perplexing factors.

Negligible data are present related to anthroponotic cutaneous leishmaniasis (ACL) treatment outcome and resultant unresponsiveness risk determinants. The role of demographic, clinical, and environmental risk associated-factors in the development of treatment failure, relapse, and chronic forms of ACL has not been studied. We carried out a case-control study for a period of 4 years (2015–2019) using culture media and nested PCR to identify the causative agent. Afterward, we analyzed the data by univariate multinomial and multiple multinomial logistic regression models and the backward elimination stepwise method. Also, we examined skin punch biopsies to study the histopathological and immunohistochemical (IHC) profile for different comparative groups. The findings identified 8 major risk factors were significantly associated with the creation of unresponsive forms. Clinical practitioners and health surveillance systems should be aware of and monitor such perplexing factors. Awareness of the major determinants for unresponsiveness to the treatment of ACL is critical to improving clinical strategies and public health measures. These multidisciplinary approaches need to address specific barriers that directly affect the treatment outcome.

Immunopathology of anthroponotic cutaneous leishmaniasis and incidental diagnostic tool of metastatic granuloma: A case-control study

BACKGROUND

Cutaneous leishmaniasis (CL) is a neglected disease with important public health concerns in many parts of the world including Iran.

OBJECTIVES

We aimed to explore the histological changes and immunohistochemical quantification of inflammatory cells and their role in the immunopathology of acute, chronic non-lupoid, and chronic lupoid skin lesions in anthroponotic CL (ACL).

METHODS

In this study, skin biopsies of 53 patients with ACL were taken. Samples were studied by light microscopy and immunohistochemistry to quantify the immune and inflammatory cells.

RESULTS

Of the 53 skin lesions, 38 were acute, nine chronic non-lupoid and six chronic lupoid. CD68⁺ macrophages were the most common cells. CD3⁺ T-lymphocytes were present as diffuse and focal dermal infiltrates and CD8⁺ cytotoxic T-lymphocytes were the dominant lymphocyte type, constituting more than 50% of the lymphocyte population. CD4⁺ T-lymphocytes in chronic non-lupoid (10.57 ± 2.37%) and chronic lupoid (14.40 ± 1.28%) lesions were more than those observed in the acute form (8.61 ± 1.31%), but the differences were not statistically significant. CD20⁺ B-lymphocytes constituted a small percentage of inflammatory cell infiltrates. CD1a + Langerhans cells showed progressively higher percentages from acute to chronic non-lupoid to chronic lupoid lesions. The differences were statistically significant (P < 0.05) between acute and chronic lupoid lesions. CD68⁺ macrophages were the most common cells and CD8⁺ T lymphocytes remained the predominant T-lymphocytes in acute, chronic non-lupoid, and chronic lupoid lesions, suggesting their central role in the pathogenesis and possible healing of CL.

CONCLUSION

Focusing on the deep dermis, periadnexal and/or peripheral margins or even papillary tip of inflammatory sites of sandfly bites, we sometimes find granuloma inside lymphatic vessels (lymphangiectatic metastatic granuloma) or even infected macrophages with engulfed Leishman bodies faraway. Knowledge of the histopathological and immunohistochemical findings for various forms of ACL is essential in improving clinical and medical strategies and crucial for proper prophylactic and therapeutic plans.

Modelling the number of dermal lesions in anthroponotic cutaneous leishmaniasis and its associated factors in Herat province, western Afghanistan, during 2012-2013

Cutaneous leishmaniasis (CL), caused by Leishmania tropica, is the main causative agent of CL in the Herat province, western Afghanistan. In CL patients, one of the most important indicators for reducing the amount of body damage and the choice of treatment is the number of dermal lesions, but there is no strong evidence in this regard. Therefore, using count regression models, the main objective of this historical cohort study was to identify the distribution of the number of dermal lesions and determine the associated factors among CL patients referring to leishmaniasis reference laboratory in Herat province, from January 2012 to December 2013. In a total of 4,127 clinically suspected CL cases, 50.20% were female and 49.80% male. Based on the results of ZINB model, which is the best model suggested by goodness-of-fit criteria, age variables (IRR = 1.007), duration of lesion (6-12 weeks compared to < 6 weeks with IRR = 1.36 and >12 weeks with IRR = 1.39 compared to <6 weeks), type of lesion(both nodule and ulcer compared to papule with IRR = 2.03), location of lesion (trunk with IRR = 1.90, upper with IRR = 1.66, lower with IRR = 1.61 and mix with IRR = 10.35 compared to head/neck/ears) and type of lesion (ulcer compared to papule with IRR = 0.50, nodule and lupoid, respectively, as IRR = 0.72 and IRR = 0.51 compared to papule) had a significant effect on the mean number of dermal lesions (p < .05). Also, our results showed that among four models used, the ZINB model represented a better performance to determine the associated probable factors about the number of dermal lesions in ACL patients. Moreover, there was a direct association between age and number of dermal lesions; in addition, duration of lesion, type of lesion and location of lesion had a significant effect on the number of dermal lesions. Therefore, a comprehensive planning is necessary for controlling and reducing the number of dermal lesions.

Evaluation of a new live recombinant vaccine against cutaneous leishmaniasis in BALB/c mice

Background

Leishmaniasis is a serious health problem in some parts of the world. In spite of the many known leishmaniasis control measures, the disease has continued to increase in endemic areas, and no effective vaccine has been discovered.

Methods

In this study, Leishmania tarentulae was used as a living factory for the production of two LACK and KMP11 immunogenic antigens in the mice body, and safety profiles were investigated. The sequences of the KMP11 and LACK L. major antigens were synthesized in the pLEXSY-neo 2.1 plasmid and cloned into E. coli strain Top10, and after being linearized with the SwaI enzyme, they were transfected into the genome of L. tarentolae. The L. tarentolae-LACK/KMP11/EGFP in the stationary phase with CpG ODN as an adjuvant was used for vaccination in BALB/c mice. Vaccination was performed into the left footpad. Three weeks later, the booster was injected in the same manner. To examine the effectiveness of the injected vaccine, pathogenic L. major (MRHO/IR/75/ER) was injected into the right footpad of all mice three weeks following the booster vaccination. In order to assess humoral immunity, the levels of IgG1, and IgG2a antibodies before and 6 weeks after the challenge were studied in the groups. In addition, in order to investigate cellular immunity in the groups, the study measured IFN-γ, IL-5, TNF-α, IL-6 and IL-17 cytokines before, 3 weeks and 8 weeks after the challenge, and also the parasite load in the lymph node with real-time PCR.

Results

The lowest level of the parasitic load was observed in the G1 group (mice vaccinated with L. tarentolae-LACK/KMP11/EGFP with CpG) in comparison with other groups (L. tarentolae-LACK/KMP11/EGFP +non-CpG (G2); L. tarentolae-EGFP + CpG (G3, control); L. tarentolae-EGFP + non-CpG (G4, control); and mice injected with PBS (G5, control). Moreover, the evaluation of immune response showed a delayed-type hypersensitivity towards Th1.

Conclusions

According to the results of this study, the live recombinant vaccine of L. tarentolae-LACK/KMP11/EGFP with the CpG adjuvant reduced the parasitic load and footpad induration in infected mice. The long-term effects of this vaccine can be evaluated in volunteers as a clinical trial in future planning.

The potential role of nicotinamide on Leishmania tropica: An assessment of inhibitory effect, cytokines gene expression and arginase profiling

Leishmaniasis represents a major health concern worldwide which has no effective treatment modality. Nicotinamide (NAm) has been used for a wide range of applications from anticancer to antimicrobial usage. This study aimed to assess the effect of NAm combination on Leishmania tropica Inhibition, as well as on cytokines gene expression and arginase (ARG) activity in L. tropica-infected macrophages in an in vitro model. The leishmanicidal effects of NAm and Glucantime (meglumine antimoniate, MA) alone and in combination (NAm/MA) were evaluated using a colorimetric assay and macrophage model. Additionally, immunomodulatory effects and enzymatic activity were assessed by analyzing Th1 and Th2 cytokines gene expression and ARG level, respectively, in infected macrophages treated with NAm and MA, alone and in combination. Findings indicated that the NAm/MA combination demonstrated greater inhibitory effects on L. tropica promastigotes and amastigotes compared with each drug individually. Docking results proved the affinity of NAm to IFN-γ, which can affirm the increased levels of IFN-γ, IL-12p40 and TNF-α as well as reductions in IL-10 secretion with a dose-response effect, especially in the combination group. The NAm/MA combination also showed a significant reduction in the level of ARG activity at all concentrations used compared to each drug individually. These findings indicate higher effectiveness of NAm plus MA in reducing parasite growth, promoting immune response and inhibiting ARG level. This combination should be considered as a potential therapeutic regimen for treatment of volunteer patients with anthroponotic cutaneous leishmaniasis (ACL) in future control programs.

Greener synthesis of Rod Shaped Zinc Oxide Nanoparticles using Lilium ledebourii tuber and evaluation of their Leishmanicidal activity

Background

Nanoparticles (NPs) with unique chemical and physical properties can be used for therapeutic purposes because of their strong antimicrobial activates. Nanoparticles have been used as an antimicrobial agents to inhibit microbial growth.

Objectives

In view of the strong antimicrobial activity of nanoparticles, the biogenic synthesis and leishmanicidal activity of rod-shaped zinc oxide (R-ZnO) nanoparticles was explored using Lilium ledebourii tuber extract.

Materials and Methods

The ensuing nanoparticles are characterized by UV-visible spectroscopy, X-ray diffraction and transmission electron microscopy and their leishmanicidal activity evaluated against the Leishmania major (L. major) by MTT assay.

Results

The R-ZnO nanoparticles displayed excellent leishmanicidal activity against the L. major as they significantly inhibited the amastigotes. The IC₅₀ values of R-ZnO nanoparticles being ~ 0.001 mg.mL^-1. R-ZnO nanoparticles can inhibit L. major growth in a dose-dependent manner under in vitro conditions.

Conclusion

A simple, low-cost feasible and eco-friendly procedure was developed for biosynthesis of R-ZnO nanoparticles using natural bioresource that can inhibit human parasite cells growth in a dose-dependent manner under in vitro conditions.