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Approximately 20 Leishmania species are known to cause cutaneous, mucocutaneous, and visceral disorders in humans. Identification of the causative species in infected individuals is important for appropriate treatment and a favorable prognosis because infecting species are known to be the major determinant of clinical manifestations and may affect treatments for leishmaniasis. Although Leishmania species have been conventionally identified by multilocus enzyme electrophoresis, genetic analysis targeting kinetoplast and nuclear DNA (kDNA and nDNA, respectively) is now widely used for this purpose. Recently, we conducted countrywide epidemiological studies of leishmaniasis in Ecuador and Peru to reveal prevalent species using PCR-RFLP targeting nDNA, and identified unknown hybrid parasites in these countries together with species reported previously. Furthermore, comparative analyses of kDNA and nDNA revealed the distribution of parasites with mismatches between these genes, representing the first report of mito-nuclear discordance in protozoa. The prevalence of an unexpectedly high rate (~10%) of genetically complex strains including hybrid strains, in conjunction with the observation of mito-nuclear discordance, suggests that genetic exchange may occur more frequently than previously thought in natural Leishmania populations. Hybrid Leishmania strains resulting from genetic exchanges are suggested to cause more severe clinical symptoms when compared with parental strains, and to have increased transmissibility by vectors of the parental parasite species. Therefore, it is important to clarify how such genetic exchange influences disease progression and transmissibility by sand flies in nature. In addition, our aim was to identify where and how the genetic exchange resulting in the formation of hybrid and mito-nuclear discordance occurs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kato, Cáceres, Gomez, Tabbabi, Mizushima, Yamamoto and Hashiguchi.)

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mannose phosphate isomerase (mpi) gene was applied to 134 skin samples collected from patients with cutaneous leishmaniasis (CL) in Peru for identification of the infecting parasite at the species level, and the results were compared with those of cytochrome b (cyt b) gene sequencing obtained in previous studies. Although most results (121/134) including 4 hybrids of Leishmania (Viannia) braziliensis and L. (V.) peruviana corresponded to those obtained in the previous study, PCR-RFLP analyses revealed the distribution of putative hybrid strains between L. (V.) peruviana and L. (V.) lainsoni in two samples, which has never been reported. Moreover, parasite strains showing discordance between kinetoplast and nuclear genes (kDNA and nDNA), so-called mito-nuclear discordance, were identified in 11 samples. Of these, six strains had the kDNAs of L. (V.) braziliensis or L. (V.) peruviana and nDNAs of L. (V.) guyanensis, and three strains had the kDNAs of L. (V.) shawi and nDNAs of L. (V.) braziliensis. The rest were identified as mito-nuclear discordance strains having kDNAs of L. (V.) braziliensis or L. (V.) peruviana and nDNAs of L. (V.) lainsoni, and kDNAs of L. (V.) lainsoni and nDNAs of L. (V.) braziliensis. The results demonstrate that Leishmania strains in Peru are genetically more complex than previously considered., Competing Interests: No authors have competing interests

To obtain further insight into geographic distribution of Leishmania species in Peru, a countrywide survey, including central to southern rainforest areas where information on causative parasite species is limited, was performed based on cytochrome b (cyt b) and mannose phosphate isomerase (mpi) gene analyses. A total of 262 clinical samples were collected from patients suspected of cutaneous leishmaniasis (CL) in 28 provinces of 13 departments, of which 99 samples were impregnated on FTA (Flinders Technology Associates) cards and 163 samples were Giemsa-stained smears. Leishmania species were successfully identified in 83 (83.8%) of FTA-spotted samples and 59 (36.2%) of Giemsa-stained smear samples. Among the 142 samples identified, the most dominant species was Leishmania (Viannia) braziliensis (47.2%), followed by L. (V.) peruviana (26.1%), and others were L. (V.) guyanensis, L. (V.) lainsoni, L. (V.) shawi, a hybrid of L. (V.) braziliensis and L. (V.) peruviana, and Leishmania (Leishmania) amazonensis. Besides the present epidemiological observations, the current study provided the following findings: 1) A hybrid of L. (V.) braziliensis and L. (V.) peruviana is present outside the Department of Huanuco, the only place reported, 2) Many cases of CL due to L. (V.) lainsoni, an uncommon causative species in Peru, were observed, and 3) L. (V.) shawi is widely circulating in southern Amazonian areas in Peru., Competing Interests: The authors have declared that no competing interests exist.

PCR-Restriction Fragment Length Polymorphism (RFLP) analyses targeting multiple nuclear genes were established for the simple and practical identification of Leishmania species without using expensive equipment. This method was applied to 92 clinical samples collected at 33 sites in 14 provinces of Ecuador, which have been identified at the species level by the kinetoplast cytochrome b (cyt b) gene sequence analysis, and the results obtained by the two analyses were compared. Although most results corresponded between the two analyses, PCR-RFLP analyses revealed distribution of hybrid strains between Leishmania (Viannia) guyanensis and L. (V.) braziliensis and between L. (V.) guyanensis and L. (V.) panamensis, of which the latter was firstly identified in Ecuador. Moreover, unexpected parasite strains having the kinetoplast cyt b gene of L. (V.) braziliensis and nuclear genes of L. (V.) guyanensis, L. (V.) panamensis, or a hybrid between L. (V.) guyanensis and L. (V.) panamensis were identified. This is the first report of the distribution of a protozoan parasite having mismatches between kinetoplast and nuclear genes, known as mito-nuclear discordance. The result demonstrated that genetically complex Leishmania strains are present in Ecuador. Since genetic exchanges such as hybrid formation were suggested to cause higher pathogenicity in Leishmania and may be transmitted by more species of sand flies, further country-wide epidemiological studies on clinical symptoms, as well as transmissible vectors, will be necessary., Competing Interests: The authors have no conflicts of interest to declare.

Background: Cutaneous and visceral forms of leishmaniasis are the most important protozoan infection in the Middle East and North Africa (MENA)., Objectives: Review the current knowledge on leishmaniasis in the MENA., Methods: The data presented in this review are gathered primarily from WHO reports and from an extensive literature search on PubMed., Results: There are four cycles of transmission of leishmaniasis: zoonotic cutaneous leishmaniasis (ZCL), induce by Leishmania ( L. ) major , transmitted by Phlebotomus ( P. ) papatasi , with rodent species of Psammomys obesus, Meriones libycus, Nesokia indica , and Rhombomys opimus are considered as host reservoirs. Zoonotic visceral leishmaniasis (ZVL) is inducing by L. infantum , transmitted by several Phlebotomus spp . of the sub-genus Larroussius and mainly P. perniciosus in more than one-half of the MENA countries and the dog species of Canis familiaris are considered as the main reservoirs. Anthroponotic cutaneous leishmaniasis (ACL), induce by L. tropica and transmitted by P. sergenti , without any non-human reservoir in most cases. Anthroponotic visceral leishmaniasis (AVL) induces by L. donovani spreads through P. alexandri , circulates exclusively in humans., Conclusion: There are many challenges facing the successful control of leishmaniasis. However, there is continuing research into the treatment of leishmaniasis and potentially vaccinations for the disease.

The importance of cryptic species is poorly understood for medical entomologists and parasitologists because of the taxonomic challenge that they pose. The recent advent and development of molecular tools to species delimitation allowed discovering an important number of cryptic species considered previously as a single morpho-species. So far, however, this form of genetic taxonomy frequently remains incomplete and needs a nomenclature description of new species. Here, we synthesize the literature of Phlebotomus chabaudi and Phlebotomus riouxi which are related species and discuss trends in their discovery. However, a lack of systematic studies leaves many questions open, such as are they cryptic or pseudocryptic species and whether one has a vectorial role? Indeed, the two closely related species are suspected as vectors of Leishmania tropica, a causative agent of cutaneous leishmaniasis in North Africa, and among priority recommendations to prepare the area for future public health challenges is understanding what is a vector. This will help to evaluate and predict vector transmission risks and therefore improve current control methods. Based on our review it is possible to suggest that possibly many times species are classified as cryptic due to inappropriate methodological designs and comparisons. In this context, a formal nomenclature and description of cryptic species was provided on the basis of an integrated taxonomy. Corroboration from independent data, including morphology, molecules and biology may provide a basis for the delimitation and formal nomenclature of these cryptic species. [ABSTRACT FROM AUTHOR]

Abstract: From 2009 to 2010, 3129 sandflies were caught in CDC light traps placed in various habitats in Ghomrassen, Tataouine governorate, southeast Tunisia, a mixed focus of human cutaneous leishmaniasis caused by Leishmania tropica and Leishmania major. Species diversity was quantified in anthropogenic, semi-anthropogenic and semi-natural locations. Sandflies were identified according to morphological characters and also by the comparative sequence analysis of a fragment of the mitochondrial cytochrome b gene to distinguish between two putative local vectors of L. tropica, namely Phlebotomus chabaudi and Phlebotomus riouxi. The lowest sandfly diversities were found in L. major sites, where the incriminated vector P. papatasi predominated in the burrows of the rodent reservoir hosts (Meriones) as well as inside and outside houses of human cases. In L. tropica sites, the incriminated peri-domestic vector Phlebotomus sergenti was the most abundant species inside houses, whereas P. riouxi or P. chabaudi was the dominant species in the semi-natural rocky habitats favoured by the putative rodent reservoir, Ctenodactylus gundi. All specimens of P. chabaudi identified molecularly had the diagnostic cytochrome b characters of P. riouxi, indicating either that the latter represents only a geographical variant of P. chabaudi or that these two species may sometimes hybridize. [Copyright &y& Elsevier]

Differences in the gut microbial content of Lutzomyia (Lu.) ayacuchensis, a primary vector of Andean-type cutaneous leishmaniasis in Ecuador and Peru, may influence the susceptibility of these sand flies to infection by Leishmania. As a first step toward addressing this hypothesis, a comparative analysis of bacterial and fungal compositions from Lu. ayacuchensis populations with differential susceptibilities to Leishmania was performed. Bacterial 16S rRNA gene amplification and Illumina MiSeq sequencing approaches were used to characterize the bacterial composition in wild-caught populations from the Andean areas of Ecuador and southern Peru at which the sand fly species transmit Leishmania (Leishmania) mexicana and Leishmania (Viannia) peruviana, respectively, and a population from the northern Peruvian Andes at which the transmission of Leishmania by Lu. ayacuchensis has not been reported. In the present study, 59 genera were identified, 21 of which were widely identified and comprised more than 95% of all bacteria. Of the 21 dominant bacterial genera identified in the sand flies collected, 10 genera had never been detected in field sand flies. The Ecuador and southern Peru populations each comprised individuals of particular genera, while overlap was clearly observed between microbes isolated from different sites, such as the number of soil organisms. Similarly, Corynebacterium and Micrococcus were slightly more dominant bacterial genera in the southern Peru population, while Ochrobactrum was the most frequently isolated from other populations. On the other hand, fungi were only found in the southern Peru population and dominated by the Papiliotrema genus. These results suggest that variation in the insect gut microbiota may be elucidated by the ecological diversity of sand flies in Peru and Ecuador, which may influence susceptibility to Leishmania infection. The present study provides key insights for understanding the role of the microbiota during the course of L. (L.) mexicana and L. (V.) peruviana infections in this important vector. [ABSTRACT FROM AUTHOR]

In recent years there has been growing interest in Sergentomyia species. Their role in the spread of mammalian leishmaniasis appears repeatedly in the literature and the possibility of its implication in Leishmania transmission to humans remains controversial. Sergentomyia ( Sintonius ) clydei is one of several cryptic species sharing therefore common morphologic criteria with others species of the subgenera Sintonius . Little is known about this specie in Tunisia. We sampled and identified different specimens including four specimens of S. clydei collected from Sidi Bouzid and Kairouan areas (center of Tunisia) using morphological tools. Male Sergentomyia clydei and Sergentomyia christophersi are known to share several morphological characters and can be mistaken for. Consequently we took advantage of 5 male S. christophersi available in our collection (Tataouin, South of Tunisia). In our study morphological tools were completed by molecular study of cytochrome b gene to identify S. clydei . For the detection of Leishmania spp. that might infect our specimens, Leishmania DNA was analyzed by amplification of kinetoplast minicircle DNA using real-time PCR and nested-PCR. Obtained result was confirmed by restriction analysis of the amplified ribosomal internal transcribed spacer 1 (ITS1). We provide in our study, the first molecular identification of S. clydei , in Tunisia. Our Neighbor Joining tree based on mitochondrial cytochrome b gene shows two different clusters. The first includes the Tunisians S. clydei and other specimens from Africa, Middle East and the Arabic peninsula, and the second cluster containing the specimens from Seychelle. Unexpectedly, we also demonstrate the infection of one anthropophilic female S. clydei by Leishmania major DNA. This finding shows that more attention should be paid when identifying parasites by molecular tools within sandfly vector. [ABSTRACT FROM AUTHOR]