Genetic Diversity and Population Structure of Leishmania infantum in Morocco as Revealed by Multilocus Sequence Typing (MLST) Approach.

Leishmania infantum is endemic in Morocco, and it causes both visceral (VL) and cutaneous leishmaniasis (CL). In this study, the multilocus sequence typing (MLST) approach was used to investigate the phylogeny and population structure of Leishmania infantum strains isolated from CL and VL patients and the canine reservoir in different leishmaniasis endemic foci in Morocco. For this purpose, eight loci (pgm, alat, me, fh, g6pd, pgd, gpi and cytb) were amplified in 40 samples, out of which 31 were successfully sequenced. The genetic diversity analysis detected a high degree of intraspecific genetic variability among the studied strains. The phylogenetic and the haplotype analyses showed that most of the strains from the same geographical areas clustered together. The recombination among Leishmania infantum strains was revealed through a splits tree analysis and the number of recombination events. Moreover, the assessment of the gene flow between Leishmania infantum and Leishmania tropica through phylogenetic analysis and haplotype diversity in two endemic foci where the two species were sympatric showed no genetic exchange between the two species.

Transmission patterns of Leishmania tropica around the Mediterranean basin: Could Morocco be impacted by a zoonotic spillover?

Cutaneous leishmaniasis (CL) due to Leishmania tropica is a neglected tropical disease characterized by a wide geographical distribution in the Mediterranean basin and is endemic in several of its countries. In addition, the vector Phlebotomus sergenti is abundantly present all around the basin. Its transmission cycle is still subject to debate. In some countries, the presence of an animal reservoir has been confirmed. In Morocco, CL due to L. tropica has risen since the 1980s and has spread widely to become the most abundant form of leishmaniasis in the territory. However, the anthroponotic transmission is so far the only recognized mode, despite recordings of L. tropica infection in animal hosts. In this review article, we assess the situation of CL due to L. tropica in the Mediterranean basin with a focus on Morocco and gather knowledge about any potential zoonotic transmission in the country. A concomitant zoonotic transmission could explain the persistence of the disease in areas where human protective measures combined with vector management did not help reduce the disease burden.

The pro-inflammatory cytokines in COVID-19 pathogenesis: What goes wrong?

The outbreak of coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, has emerged in China in December 2019 and rapidly spread to more than 196 countries worldwide. The physiopathology of human SARS-CoV-2 has not been completely understood, but its pathogenesis has been linked to a disproportionate response of the immune system. Just as described for SARS and MERS, an uncontrolled systemic inflammatory response, known as cytokine release syndrome (CRS) was observed in severe COVID-19 patients. It results from the release by immune and non-immune effector cells of substantial amounts of pro-inflammatory cytokines and appears to contribute to SARS-CoV-2 pulmonary inflammation and extensive lung damage. In addition, hyper-coagulation and thrombosis resulted from the important release of pro-inflammatory cytokines contribute to the lethality of subjects severely infected with SARS-CoV-2. It is therefore essential to have a deep understanding of the various cytokines involved in this exacerbated immune response, and that could be targeted by potential immunological treatments. The aim of this review was to gather the current knowledge about the role of pro-inflammatory cytokines, namely IL-1ß, IL-6, IL-8, IL-17 and TNFα in SARS-CoV-2 CRS, the probable causes and clinical outcomes of this phenomenon in severe cases of COVID-19.

[Generalized old world leishmaniasis: first Moroccan case in an immunocompetent adult?] / Leishmaniose généralisée de l'Ancien monde : Premier cas marocain chez un adulte immunocompétent ?

Background: Post-kala-azar dermal Leishmaniasis (PKDL) is a rare skin syndrome observed after treatment of visceral Leishmaniasis (VL) with pentavalent antimonial organic salts, never described in Morocco before. Here we report a case in an immunocompetent adult. Case: A 36-year-old-man from Tata in southern Morocco, with a history of visceral Leishmaniasis 2 years before and treated with meglumine antimoniate and amphotericin B with good clinical course, was hospitalized in dermatology for an erythematous papulo-nodular closet of the face. Six months ago, he presented oral mucosa involvement, then 3 months later, cutaneous lesions appeared on the face. The dermatological examination revealed a papulo-nodular erythematous closet extending to the nose and both cheeks, crusty and lupoid lesions on the forehead, around the eyes and chin, associated with an ulcerative and painless lesion on the heeL. The examination of the oral mucosa revealed an ulceration of the posterior third of the tongue and a papillomatous aspect of the soft palate. The skin biopsy and smear found some amastigote forms of Leishmania bodies. ITS1 PCR was positive (genus Leishmania). The HIV serology was negative. The diagnosis of PKDL was then evoked. The patient received intra-muscular injections of meglumine antimoniate with good progress. Conclusion: To our knowledge, this is the first case of generalised leishmaniasis suggesting PKDL reported in a Moroccan immunocompetent adult.