Myriam Riyad

Prof. Myriam Riyad

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 January 2022 in PLOS Neglected Tropical Diseases
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Journal Article
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ISImane El Idrissi Saik
Imane El Idrissi Saik
CBChaimaa Benlabsir
Chaimaa Benlabsir
HFHassan Fellah
Hassan Fellah
MLMeryem Lemrani
Meryem Lemrani
MRMyriam Riyad
Myriam Riyad
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.

31 May 2023 in Pathogens
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Journal Article
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SMSara El Mazini
Sara El Mazini
MBMourad Barhoumi
Mourad Barhoumi
IMIdris Mhaidi
Idris Mhaidi
ODOthmane DAOUI
Othmane DAOUI
MKMouad Ait Kbaich
Mouad Ait Kbaich
MLMeryem Lemrani
Meryem Lemrani
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.

1 November 2021 in Cytokine
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Journal Article
Closed access
Ayyoub KihelAyyoub Kihel
Ayyoub Kihel
IHIkram Hammi
Ikram Hammi
DDDounia Darif
Dounia Darif
MLMeryem Lemrani
Meryem Lemrani
MRMyriam Riyad
Myriam Riyad
KAKhadija AKARID
Khadija AKARID

12 April 2018 in Infectious Diseases of Poverty
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Journal Article
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TMTarik Mouttaki
Tarik Mouttaki
HMHasnaa MAKSOURI
Hasnaa MAKSOURI
JMJilali El Mabrouki
Jilali El Mabrouki
GMGema Merino-Espinosa
Gema Merino-Espinosa
HFHassan Fellah
Hassan Fellah
MRMyriam Riyad
Myriam Riyad
Leishmaniases are vector-borne diseases caused by the protozoa of the Leishmania genus. The clinical spectrum of these diseases extends from benign dermal lesions to visceral forms. In the Mediterranean region, zoonotic visceral leishmaniasis (ZVL) is caused by L. infantum. If untreated within two years, the disease usually leads to death. In Morocco, ZVL is endemic in the north, with a hundred cases notified each year, mostly in children aged below five years. Here, we report on two clinical observations in infants presenting unusual concomitant VL and cutaneous leishmaniasis (CL) in Morocco. In this case study, we report on two infants aged nine and 12 months old. They both have a history of febrile splenomegaly, anemia, and pallor of mucous membranes. Visceral leishmaniasis was confirmed by parasitological diagnosis (positive bone marrow smear and screening of anti-L. infantum antibodies). However, the clinical examination also showed cutaneous lesions that suggested the presence of CL. This was reinforced by the patients having a history of living or traveling to endemic foci. Thus, direct examination, culture, and PCR-RFLP (ITS1-Hae 3) were carried out on the patients’ dermal exudates. In one of the infants, CL was associated with L. infantum, while in the other it was associated with L. tropica. The infants were treated as according to the recommendations of the Ministry of Health. Both patients were cured in two months; defervescence, reduction of splenomegaly, and healing of cutaneous lesions were all observed. These singular patients illustrate the clinical polymorphism of CL and the necessity of updating the differential diagnosis of leukemia-like syndromes, including VL, in children living in or travelling to known endemic areas. These observations suggest a change in the Mediterranean VL phenotype that may be associated with CL.

31 January 2023 in Microorganisms
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Journal Article
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HFHajar El Filaly
Hajar El Filaly
AOAhmed OUTLIOUA
Ahmed OUTLIOUA
CDChristophe Desterke
Christophe Desterke
EZEcharki Zerif
Echarki Zerif
WBWafaa Badre
Wafaa Badre
KAKhadija AKARID
Khadija AKARID
Genetic polymorphisms at the IL-1 cluster are associated with increased Helicobacter pylori (H. pylori)-associated disease risk in an ethnically dependent manner. Due to the corroborated role of IL-1β in H. pylori infection progression, our aim is to depict the impact of IL1B rs1143627 and rs16944 as well as the IL1RN variable number of identical tandem repeats (VNTR) on the clinical and biological features of Moroccan H. pylori-infected patients. A total of 58 patients with epigastralgic pain were referred to the gastroenterology department for histopathological and clinical analysis. DNA extraction from antrum and fundus biopsies and PCR–RFLP were performed to detect polymorphisms. As a result, VNTR was significantly associated with IL-1β antrum levels (p-value = 0.029), where the *1/*4 genotype showed a positive association with upregulated cytokine levels in the antrum and was clustered with H. pylori-infected patients’ features and higher levels of IL-1β in the antrum and fundus. Likewise, *1/*1 genotype carriers clustered with severe gastritis activity and H. pylori density scores along with low levels of IL-1β in the antrum and fundus, while the *1/*2 genotype was clustered with non-infected-patient features and normal IL-1β levels. In conclusion, VNTR might be an interesting predictor to identify patients at risk of developing H. pylori-associated pathologies.

26 December 2022 in Experimental Parasitology
Verified
Journal Article
Closed access
DDDounia DARIF
Dounia DARIF
IIImane NAIT IRAHAL
Imane NAIT IRAHAL
IHIkram Hammi
Ikram Hammi
Ayyoub KihelAyyoub Kihel
Ayyoub Kihel
MKMohamed Reda Kachmar
Mohamed Reda Kachmar
KAKhadija AKARID
Khadija AKARID