Molecular detection and identification of Leishmania infection in naturally infected sand flies in a focus of cutaneous leishmaniasis in northern Morocco

Abstract

BackgroundCutaneous leishmaniasis is an infectious disease caused by various species of the flagellate protozoan Leishmania. During the past 20 years, cutaneous leishmaniasis has emerged as a major public health threat in Morocco. The main objective of this study was to study the occurrence of Leishmania infection in vectors and to identify sand fly blood meal sources in an endemic locality of cutaneous leishmaniasis within Sefrou province, where the vectors of leishmaniasis were still unknown.Methods2650 sand flies were collected using CDC miniature light traps and identified morphologically. The identified sand flies were tested for Leishmania infection by nested PCR. The source of blood meal of 10 freshly engorged females: 6 Phlebotomus longicuspis and 4 Phlebotomus sergenti, was determined using the Cyt b sequence.ResultsThe collected sand flies consisted of 10 species, seven of which belonged to the genus Phlebotomus and three to the genus Sergentomyia. The most abundant species was P. longicuspis, accounting for 72% of the total sand flies collected. In females of three P. longicuspis and four P. sergenti, Leishmania infantum and Leishmania tropica DNA was detected, respectively.The source of blood meal of engorged females showed that all sand flies tested fed on humans.ConclusionsWe report for the first time the natural infection of P. longicuspis with L. infantum in Morocco. The high frequency of this species in this region, in addition to its anthropophilic character make P. longicuspis the putative vector of L. infantum in this cutaneous leishmaniasis focus where L. tropica is confirmed as the causative agent of the disease and P. sergenti as its vector. The presence of L. infantum, and its presumed vector in this area, makes this a site of high risk of visceral leishmaniasis, mostly because of the proximity of a focus of human and canine visceral leishmaniasis.

Risk factors for the expansion of cutaneous leishmaniasis by Leishmania tropica : Possible implications for control programmes

“…Nonetheless, most sandfly species for which information is available ( P. ariasi, P. perniciosus, P. perfiliewi, P. papatasi, Lutzomyia longipalpis, etc .) appear to be generalists (González et al., ; Guy, Killick‐Kendrick, Gill, Rioux, & Bray, ; Macedo‐Silva et al., ; Maia et al., ) rather than specialists ( P. sergenti, P. longicuspis ) in their host range (Es‐Sette, Ajaoud, Laamrani‐Idrissi, Mellouki, & Lemrani, ). In this work, human, cat, rabbit and bird blood was detected in blood‐fed P. sergenti females showing that P. sergenti fed not only on human but also on a wide range of animals.…”

Species composition, activity patterns and blood meal analysis of sand fly populations (Diptera: Psychodidae) in the metropolitan region of Thessaloniki, an endemic focus of canine leishmaniasis.

“…Vector species are generally considered opportunistic feeders, thus their host preferences should be determined taking into account the structure of the sampling habitat (Rossi et al 2008). For instance P. sergenti populations from Sanliurfa (Turkey) were found to be ornithophilic (Svobodova et al 2003), whereas the same species in Morocco exhibited an anthropophilic character (Es-Sette et al 2014). However the engorged sand flies examined here, were all collected from a multi-species animal facility, where several different blood sources were available (Table 1).…”

“…Our experimentation suggested that at least 40 ng, but usually 100-150 ng, of template DNA from blooded sand fly abdomens was necessary for providing a concentration of the targeted PCR product suitable for direct sequencing. For the identification of the source of blood meals, a 359bp conserved region of the vertebrate host mitochondrial cytochrome b gene (cyt b) was amplified exactly as described by Es-Sette et al (2014), except for the polymerase and buffer which was the HotStarTaq plus master mix kit (Qiagen). DNA of a male sand fly was included in each batch of reactions as a negative control.…”

Toscana virus isolated from sandflies, Morocco

“…Thus, the presence of P. sergenti , vector of L. tropica in Azilal province [9] and P. longicuspis , vector of L. infantum in Sefrou [10] province makes those foci of high risk, as the two phlebotomine species are incriminated in the transmission of TOSV as well as L. tropica and L. infantum causative agents of cutaneous and visceral leishmaniasis respectively.…”