Updates on Geographical Dispersion of Leishmania Parasites Causing Cutaneous Affections in Algeria

Occurrence of Leishmania spp. in phlebotomine sand flies and dogs in Guelma region, North-eastern Algeria

Leishmania spp. are sand fly-borne parasitic protozoa of worldwide distribution that may severely affect the health and welfare of dogs as well as of other mammalian species, including humans. Algeria is among the most affected countries, counting several cases of Leishmania infantum infection in humans and dogs. Here, we assessed the occurrence of Leishmania species in both phlebotomine sand fly and dogs in the Guelma region, Northeast of Algeria. Sand flies were collected from July to September 2022, followed by a survey of canine leishmaniasis (CanL) from September 2023 to February 2024. Additionally, to understand the risk of human infection a retrospective data on cases of leishmaniasis recorded in the region from 2012 to 2023 were reported. Sand fly specimens and canine blood samples were tested by quantitative PCR (qPCR) for Leishmania spp., while dog serum samples were processed for anti-L. infantum antibodies detection by immunofluorescent antibody test (IFAT). Of the 1478 sand flies (n = 318 females; n = 1160 males), seven species were identified (i.e., Phlebotomus papatasi, Ph. perfiliewi, Ph. sergenti, Ph. perniciosus, Ph. longicuspis, Ph. ariasi, and Sergentomyia minuta). Leishmania spp. was detected in Ph. perniciosus, Ph. perfiliewi, Ph. papatasi, and Ph. sergenti (i.e., 3.7 %; n = 10). The overall seroprevalence rate was 58.2 %, with 1.6 % of dog blood samples positive for L. infantum at molecular screening. Multivariate analysis of the different risk factors revealed that CanL seropositivity was strongly related to dog age (> 1 year) (OR = 8.35, 95 % CI: 3.43-23.93), the autumn season (OR = 2.95, 95 % CI: 1.33-8.62), and lack of insecticide application (OR = 6.69, 95 % CI: 2.61-22.02). A total of 71 human cases of cutaneous (CL) and visceral (VL) leishmaniasis were recorded. Data presented reveal the occurrence of CanL in Guelma region, advocating for control program measures to be implemented in this part of Algeria.

Phlebotomine sand fly survey, blood meal source identification, and description of Sergentomyia imihra n. sp. in the central Sahara of Algeria

BACKGROUND

Phlebotomine sand flies (Diptera: Psychodidae) are important vectors of various pathogens, mainly Leishmania parasites. In the Old World, the most important genus in term of pathogens transmission is the genus Phlebotomus, which includes many proven or suspected vectors of several Leishmania species, while the genus Sergentomyia remains so far unproven as a vector of human pathogens. Algeria is one of the most affected countries by human leishmaniasis.

METHODS

In the present study, an entomological survey was carried out in two provinces, Ghardaïa and Illizi, located in the north and central Sahara, respectively, where cases of human leishmaniasis are recorded. Our goal was to understand the role of the local sand fly species in the transmission of Leishmania parasites and to analyze their blood meal preferences. Collected sand flies were identified by a combination of morphological and molecular approaches that included DNA-barcoding and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) protein profiling. In addition, female blood meals were analyzed by peptide mass mapping using MALDI-TOF MS.

RESULTS

In total, 640 sand fly specimens belonging to Phlebotomus and Sergentomyia genera were collected in the two provinces. Sergentomyia antennata and Se. fallax were most abundant species in Ghardaïa, and Ph. papatasi and Ph. alexandri in Illizi. In addition, a new sand fly species was described in Illizi named Sergentomyia (Sergentomyia) imihra n. sp. Blood meal analysis of the engorged females revealed various mammalian hosts, especially goats, but also humans for Phlebotomus papatasi and Ph. alexandri, suggesting that these vector species are opportunistic feeders.

CONCLUSIONS

Integrative approach that combined morphological analysis, sequencing of DNA markers, and protein profiling enabled the recognition and description of a new Sergentomyia species, raising the number of the Algerian sand fly fauna to 27 species. Further sand fly surveillance in the central Sahara is recommended to identify the thus-far unknown males of Se. imihra n. sp.

Case Report: First Report of Mucocutaneous Leishmaniasis in Algeria: Observations from a Case Report

We present the first case of mucocutaneous leishmaniasis in Algeria, diagnosed in an immunocompetent 42-year-old man exhibiting an infiltrated and ulcerated plaque leading to macrocheilitis of the entire lower lip. He was a police officer who lived in a village in Ain El Hammam (Kabylie region, known as an active focus of zoonotic visceral leishmaniasis) without any history of travel for the previous 3 years. He suffered from cutaneous lesions for 22 months due to the misdiagnosis of a skin lesion resembling other diseases such as Crohn disease or sarcoidosis. A compilation of clinical, histopathological, parasitological, and molecular examinations revealed Leishmania infantum as the etiologic agent. The patient was treated with meglumine antimoniate, which resulted in the complete disappearance of the lesion 4 months after treatment.

Anti-Leishmanial Effects of a Novel Biocompatible Non-Invasive Nanofibers Containing Royal Jelly and Propolis against Iranian Strain of Leishmania major (MRHO/IR/75/ER): an In-Vitro Study

Background

Current medications especially the pentavalent antimonial compounds have been used as the first line treatment of cutaneous leishmaniasis (CL), but they have limitations due to serious side effects such as drug resistance, cardio and nephrotoxicity, and high costs. Hence, the demand to find more usable drugs is evident. Synthesis and development of natural, effective, biocompatible, and harmless compounds against Leishmania major is the principal priority of this study.

Methods

By electrospinning method, a new type of nanofiber were synthesized from royal jelly and propolis with different ratios. Nanofibers were characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), Contact angle, and Fourier-transform infrared spectroscopy (FTIR). The Half-maximal inhibitory concentration (IC50), Half-maximal effective concentration (EC50) and the 50% cytotoxic concentration (CC50) for different concentrations of nanofibers were determined using quantitative calorimetric methods. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and flow cytometry were performed as complementary tests.

Results

The results showed that the proposed formulas provide a new achievement that, despite the significant killing activity on L. major, has negligible cytotoxicity on the host cells. Royal jelly nanofibers have significantly shown the best 72 hours results (IC50= 35 μg/ml and EC50=16.4 μg/ml) and the least cytotoxicity.

Conclusion

This study presents a great challenge to introduce a new low-cost treatment method for CL, accelerate wound healing, and reduce scarring with minimal side effects and biocompatible materials. Royal jelly and propolis nanofibers significantly inhibit the growth of L. major in-vitro.

Sand Flies (Diptera: Psychodidae): Fauna and Ecology in the Northeast of Algeria

Sand flies (Diptera: Psychodidae) transmit several Leishmania (Kinetoplastida: Trypanosomatidae) species, which cause leishmaniasis, a significant public health concern in Algeria. We compared sand fly species abundance and composition among different biotopes (urban, peri-urban, rural areas), bioclimatic zones (humid, sub-humid, semi-arid), and elevation ranges. We also used the additive partitioning of beta diversity to test whether the variation in sand fly composition among biotopes, bioclimatic zones, and elevation ranges is due to species turnover or community subsetting. In total, 7,478 specimens were captured; of which, 7,162 (51.5% males vs. 48.5% females) belong to eight species: Phlebotomus perniciosus Newstead, 1911 (77.4% of the total captured specimens), Phlebotomus perfiliewi Parrot, 1930 (14.6%), Phlebotomus longicuspis Nitzulescu, 1911 (5.9%), Phlebotomus papatasi Scopoli, 1786 (<1%), Phlebotomus sergenti Parrot, 1917 (<1%) and Phlebotomus chadlii Rioux, Juminer et Gibily 1966 (<1%), Sergentomyia minuta Adler et Theodor, 1927 (1%), and Sergentomyia fallax Parrot, 1921 (<1%). Sand fly total abundance showed negative correlations with altitude and was significantly higher in rural areas. Sandfly community composition was significantly different between rural and urban/peri-urban areas. The additive partitioning of beta diversity showed that 71.4% of the compositional dissimilarity among elevation ranges and bioclimates was due to sand fly species turnover, and 28.6% resulted from nestedness. However, the variation in sand fly composition among different biotopes was mainly due to community nestedness. Findings from this study help define the risk of Leishmania transmission and develop methods for vector control in Mila province and Algeria as a whole.

Fatty Acid Profiles of Leishmania major Derived from Human and Rodent Hosts in Endemic Cutaneous Leishmaniasis Areas of Tunisia and Algeria

Leishmaniasis is a protozoal vector-borne disease that affects both humans and animals. In the Mediterranean Basin, the primary reservoir hosts of Leishmania spp. are mainly rodents and canids. Lipidomic approaches have allowed scientists to establish Leishmania spp. lipid profiles for the identification of cell stage specific biomarkers, drug mechanisms of action, and host immune response. Using an in silico approach of global network interaction between genes involved in fatty acid (FA) synthesis followed by the GC-MS approach, we were able to characterize the fatty acid profiles of L. major derived from human and rodent hosts. Our results revealed that the lipid profile of L. major showed similarities and differences with those already reported for other Leishmania species. Phospholipids are the predominant lipid class. FA composition of rodent parasites was characterized by a lower abundance of the precursor C18:2(n-6). One of the rodent clones, which also expressed the lowest lipid abundance in PL and TAG, was the least sensitive clone to the miltefosine drug and has the lowest infection efficiency. Our findings suggest that the lipid composition variation may explain the response of the parasite toward treatment and their ability to infect their host.

Amputation of a type II diabetic patient with cutaneous leishmaniasis due to Leishmania major

Background

Leishmaniases are neglected tropical diseases of public health concern in Algeria. The immunocompromised patients with HIV, autoimmune diseases, or chronic alcohol abuse are at a higher risk of leishmaniasis. Herein, we present the case of an immunocompetent diabetic patient infected by Leishmania major, leading to life-threatening consequences.

Case presentation

An Algerian diabetic patient developed a cutaneous lesion with large polymorphous inflamed granuloma and pyoderma gangrenosum in the left foot, following L. major infection. A delayed follow-up led to a treatment failure, resulting in the amputation.

Conclusions

This report highlights the absence of timely treatment of Leishmania infection as a life-threatening point among high-risk diabetic patients. Clinicians should be aware of this parasitosis leading to severe complications in diabetic patients.

Photodynamic therapy for leishmaniasis: Recent advances and future trends

Leishmaniasis has infected more than 12 million people worldwide. This neglected tropical disease, causing 20,000-30,000 deaths per year, is a global health problem. The emergence of resistant parasites and serious side effects of conventional therapies has led to the search for less toxic and non-invasive alternative treatments. Photodynamic therapy is a promising therapeutic strategy to produce reactive oxygen species for the treatment of leishmaniasis. In this regard, natural and synthetic photosensitizers such as curcumin, hypericin, 5-aminolevulinic acid, phthalocyanines, phenothiazines, porphyrins, chlorins and nanoparticles have been applied. In this review, the recent advances on using photodynamic therapy for treating Leishmania species have been reviewed.