Development of a Molecular Tool for the Identification of Leishmania Reservoir Hosts by Blood Meal Analysis in the Insect Vectors

Abstract

The transmission of parasites of the genus Leishmania involves a large diversity of mammalian reservoir hosts. However, many of these are yet to be identified, mainly in isolated biotopes such as the Amazonian rain forest. Furthermore, the trophic preferences of insect vectors have major epidemiologic implications. In this study, we developed a molecular tool for the identification of blood meals of phlebotomine sand flies. This assay is based on specific amplification and sequencing of the blood meal-derived single copy prepronociceptin (PNOC) gene, which is used as a target in phylogenetic studies of mammals. Sand flies were identified simultaneously with the blood-meal identification, using molecular analysis of a ribosomal locus. After a systematic assessment of the sensitivity and specificity of polymerase chain reaction amplification of the PNOC gene using human fed sand flies, the assay was tested on wild-caught sand flies. This work has important implications for the discovery of new Leishmania reservoir hosts and for a better understanding of complex parasite life cycles.

Isolation, full genomic characterization and neutralization-based human seroprevalence of Medjerda Valley virus, a novel sandfly-borne phlebovirus belonging to the Salehabad virus complex in northern Tunisia

“…Therefore, it is probable that MVV is transmitted by sandfly species of the subgenus Larroussius. A similar study performed in a rural setting in Tunisia showed that P. perniciosus feed mostly on cattle (92 %) and less on humans (4.5 %), and therefore this sandfly species is highly zoophilic (Haouas et al, 2007). However, in urban and peri-urban areas, where sandfly females become deprived of livestock, they may adapt to bite humans and dogs more frequently (Rossi et al, 2008).…”

Establishment of a molecular tool for blood meal identification in Malaysia

“…The fragment fulfilled the requirement of relatively short size and enough sequence divergence to achieve objectives of the study. It is therefore likely to find a sequence entry of an unknown sample or at least of a related species [3] . Moreover, cytb has been widely used in identifying blood meal due to their high copy numbers and sufficient genetic variation at the primary sequence level among vertebrate taxa [17,23] .…”

“…It is a challenge to conduct subsequent examination of the host's efficiency to transmit infectious agent to the vector organisms under controlled condition [2] . Moreover, such laboratory-based estimates may fail to capture the true distribution of host competencies because of unknown consequences of host selection behavior by vector organisms or the unmeasured contributions of cryptic reservoir hosts [3,4] .…”

“…Molecular based assays have been developed to detect and identify blood meal sources of some insect vectors but most studies were focused on human blood [11] . Only few studies concerning host preference patterns were conducted for identification of vertebrate species [3,12] . These studies were based on the analysis of mitochondrial cytochrome b (cytb) gene which has been widely used [13][14][15][16][17] .…”

Identification of blood meals in field captured sand flies by a PCR-RFLP approach based on cytochrome b gene

“…In this sense, thestudy of blood meal sources of vectors plays an essential role.Accordingly, serological techniquesas ELISA were appliedas first approachin this way (De Colmenares et al 1995, Bongiorno et al 2003, although these methods have been replaced by molecular tools for their better accuracy (Mukabana et al 2002, Haouas et al 2007, Kent 2009,Maleki-Ravasan et al 2009). Amplification by polymerase chain reaction (PCR) and subsequent sequencingis widely used to study bloodmeal preferences in sand flies and other vectors as mosquitoes or ticks (Kirstein and Grey 1996, Oshagi et al 2006, Danabalan et al 2014.Thus, different molecular targets like cytochrome b (cytb), cytochrome oxidase I (COI) and prepronociceptin (PNOC) are being used to detect the origin of blood meals (Kocher et al 1989, Haoaus et al 2007, Abassi et al 2009).…”