Genetic diversity of Leishmania tropica in Morocco: does the dominance of one haplotype signify its fitness in both predominantly anthropophilic Phlebotomus sergenti and human beings?

In Morocco, cutaneous leishmaniasis (CL) caused by Leishmania tropica is endemic to locations where the predominantly anthropophilic blood-feeding Phlebotomus sergenti and humans co-perpetuate. The objective of this study was to explore whether the range of epidemiological features of CLcould be linked to the range of L. tropica genetic heterogeneity and to further explore the relationships between the genetic diversity of L. tropica in both P. sergenti and humans. L. tropica DNAwas extracted from dermal scarping smears of 125 CLpatients. Genetic polymorphisms were analyzed by sequencing the internal transcribed spacer (ITS) 1 and 5.8S rDNAgene. Nucleotide diversity (π), haplotype diversity (Hd) and Tajima's D test for neutrality, as well as overall and pairwise FSTvalues, were calculated using Arlequin ver 3.5 software. Out of the 125 amplified DNAsequences, 93 were completely sequenced and 13 L. tropica haplotypes were identified, which confirmed the significant genetic heterogeneity of L. tropica in Morocco. The most common haplotype included 74 out of 93 sequences; this haplotype is not only widely represented but was also detected in P. sergenti, which is known to be the most abundant species in the studied foci. Considering the negative value calculated using Tajima's D index, we briefly discussed the hypothesis that the L. tropica common haplotype propagation could be a sign of its fitness in P. sergenti and human hosts. Furthermore, analysis of molecular variance (AMOVA) shows significant correlations between intraspecific variants of L. tropica and patients' geographic origins. The long-term goals of the present pilot study are to further explore the relationships between the genetic diversity of L. tropica in human and P. sergenti populations.

Epidemiologic study and molecular detection of Leishmania and sand fly species responsible of cutaneous leishmaniasis in Foum Jamâa (Azilal, Atlas of Morocco).

The region of Foum Jamâa (province of Azilal) has become endemic for cutaneous leishmaniasis (CL) since 2006. The objective of this study was to investigate molecular identification of the etiological agent of CL in this region; we also carried out an entomological survey of Phlebotomine sand flies (Diptera: Psychodidae) in this focus to study the sand fly fauna, species composition, and the monthly prevalence of sand flies during 1 year. In the period between 2009 and 2010, skin scrapings spotted on glass slides were collected from 119 patients, aged from 9 months to 70 years old, who came from 43 localities distributed in 3 sectors in Foum Jamâa (FJ). The ITS1 PCR-RFLP was used to identify the Leishmania parasite responsible for the recent cases of CL in FJ. Our results revealed that the disease is caused by L. tropica. No significant association was observed between gender and the rate of CL in presenting patients, while the highest rate of positive lesions was found in the age group of 9 years old or under (86.67%). In this study, we found also that L. tropica infection mostly caused single lesions (67.90%) that were located in the face (96.30%). Morphological identification was performed on a total of 1152 sand flies (23% females and 77% males) collected by sticky paper traps. 57% of the total collected flies were identified as Phlebotomus (Paraphlebotomus) sergenti (Parrot).