The Genetic Relationship between Leishmania aethiopica and Leishmania tropica Revealed by Comparing Microsatellite Profiles

Background Leishmania (Leishmania) aethiopica and L. (L.) tropica cause cutaneous leishmaniases and appear to be related. L. aethiopica is geographically restricted to Ethiopia and Kenya; L. tropica is widely dispersed from the Eastern Mediterranean, through the Middle East into eastern India and in north, east and south Africa. Their phylogenetic inter- relationship is only partially revealed. Some studies indicate a close relationship. Here, eight strains of L. aethiopica were characterized genetically and compared with 156 strains of L. tropica from most of the latter species' geographical range to discern the closeness. Methodology/Principal Findings Twelve unlinked microsatellite markers previously used to genotype strains of L. tropica were successfully applied to the eight strains of L. aethiopica and their microsatellite profiles were compared to those of 156 strains of L. tropica from various geographical locations that were isolated from human cases of cutaneous and visceral leishmaniasis, hyraxes and sand fly vectors. All the microsatellite profiles were subjected to various analytical algorithms: Bayesian statistics, distance-based and factorial correspondence analysis, revealing: (i) the species L. aethiopica, though geographically restricted, is genetically very heterogeneous; (ii) the strains of L. aethiopica formed a distinct genetic cluster; and (iii) strains of L. aethiopica are closely related to strains of L. tropica and more so to the African ones, although, by factorial correspondence analysis, clearly separate from them. Conclusions/Significance The successful application of the 12 microsatellite markers, originally considered species-specific for the species L. tropica, to strains of L. aethiopica confirmed the close relationship between these two species. The Bayesian and distance-based methods clustered the strains of L. aethiopica among African strains of L. tropica, while the factorial correspondence analysis indicated a clear separation between the two species. There was no correlation between microsatellite profiles of the eight strains of L. aethiopica and the type of leishmaniasis, localized (LCL) versus diffuse cutaneous leishmaniasis (DCL), displayed by the human cases

Multilocus Microsatellite Typing reveals intra-focal genetic diversity among strains of Leishmania tropica in Chichaoua Province, Morocco

AbstractIn Morocco, cutaneous leishmaniasis (CL) caused by Leishmania (L.) tropica is a major public health threat. Strains of this species have been shown to display considerable serological, biochemical, molecular biological and genetic heterogeneity; and Multilocus Enzyme Electrophoresis (MLEE), has shown that in many countries including Morocco heterogenic variants of L. tropica can co-exist in single geographical foci. Here, the microsatellite profiles discerned by MLMT of nine Moroccan strains of L. tropica isolated in 2000 from human cases of CL from Chichaoua Province were compared to those of nine Moroccan strains of L. tropica isolated between 1988 and 1990 from human cases of CL from Marrakech Province, and also to those of 147 strains of L. tropica isolated at different times from different worldwide geographical locations within the range of distribution of the species. Several programs, each employing a different algorithm, were used for population genetic analysis. The strains from each of the two Moroccan foci separated into two phylogenetic clusters independent of their geographical origin. Genetic diversity and heterogeneity existed in both foci, which are geographically close to each other. This intra-focal distribution of genetic variants of L. tropica is not considered owing to in situ mutation. Rather, it is proposed to be explained by the importation of pre-existing variants of L. tropica into Morocco

Genetic, serological and biochemical characterization of Leishmania tropica from foci in northern Palestine and discovery of zymodeme MON-307

Background Many cases of cutaneous leishmaniasis (CL) have been recorded in the Jenin District based on their clinical appearance. Here, their parasites have been characterized in depth. Methods Leishmanial parasites isolated from 12 human cases of CL from the Jenin District were cultured as promastigotes, whose DNA was extracted. The ITS1 sequence and the 7SL RNA gene were analysed as was the kinetoplast minicircle DNA (kDNA) sequence. Excreted factor (EF) serotyping and multilocus enzyme electrophoresis (MLEE) were also applied. Results This extensive characterization identified the strains as Leishmania tropica of two very distinct sub-types that parallel the two sub-groups discerned by multilocus microsatellite typing (MLMT) done previously. A high degree of congruity was displayed among the results generated by the different analytical methods that had examined various cellular components and exposed intra-specific heterogeneity among the 12 strains. Three of the ten strains subjected to MLEE constituted a new zymodeme, zymodeme MON-307, and seven belonged to the known zymodeme MON-137. Ten of the 15 enzymes in the profile of zymodeme MON-307 displayed different electrophoretic mobilities compared with the enzyme profile of the zymodeme MON-137. The closest profile to that of zymodeme MON-307 was that of the zymodeme MON-76 known from Syria. Strains of the zymodeme MON-307 were EF sub-serotype A2 and those of the zymodeme MON-137 were either A9 or A9B4. The sub-serotype B4 component appears, so far, to be unique to some strains of L. tropica of zymodeme MON-137. Strains of the zymodeme MON-137 displayed a distinctive fragment of 417 bp that was absent in those of zymodeme MON-307 when their kDNA was digested with the endonuclease RsaI. kDNA-RFLP after digestion with the endonuclease MboI facilitated a further level of differentiation that partially coincided with the geographical distribution of the human cases from which the strains came. Conclusions The Palestinian strains that were assigned to different genetic groups differed in their MLEE profiles and their EF types. A new zymodeme, zymodeme MON-307 was discovered that seems to be unique to the northern part of the Palestinian West Bank. What seemed to be a straight forward classical situation of L. tropica causing anthroponotic CL in the Jenin District might be a more complex situation, owing to the presence of two separate sub-types of L. tropica that, possibly, indicates two separate transmission cycles involving two separate types of phlebotomine sand fly vector

Epidemiological and clinical features of cutaneous leishmaniases in Jenin District,Palestine, including characterisation of the causative agents in clinical samples

During 2002–2009, 466 cases of cutaneous leishmaniasis (CL) were reported from Jenin District, Palestine, affecting both genders. The average annual incidence was 23 cases per 100 000 inhabitants, increasing with age in children. Most cases presented a single lesion, generally on the face. Diagnosis and species identification was done by applying internal transcribed spacer 1 (ITS1) RFLP analysis to 47 isolates, of which 44 (93.6%) were Leishmania tropica and 3 (6.4%) were L. major. RFLP analysis was also performed on 256 skin tissue scrapings spotted onto filter papers, showing that 138 (53.9%) were positive, of which 50.7% were infected with L. tropica, 17.4% with L. major and 2.9% with L. donovani s.l., and 29.0% could not be identified. This is the first report from Palestine on human CL caused by L. infantum. Nine of the strains of L. tropica were subjected to multilocus enzyme electrophoresis, six of which belonged to the zymodeme MON-137 and three to a new zymodeme (MON-307). This separation was corroborated by excreted factor serotyping. This observation modifies the classical epidemiological view of CL in Palestine. Jenin District is an active focus of CL caused by L. tropica, where Phlebotomus sergenti, the putative vector, is abundant. These data suggest that CL is a zoonotic infection, but an animal reservoir has not been found.This research was supported by the Deutsche Forschungsgemeinschaft (DFG) as part of a German–Israeli–Palestinian co-operation project on the Emergence of Cutaneous Leishmaniasis in the Middle East: an investigation of Leishmania tropica in the Palestinian Authority and Israel

Identification of geographically distributed sub-populations of Leishmania (Leishmania) major by microsatellite analysis

<p>Abstract</p> <p>Background</p> <p><it>Leishmania </it>(<it>Leishmania</it>) <it>major</it>, one of the agents causing cutaneous leishmaniasis (CL) in humans, is widely distributed in the Old World where different species of wild rodent and phlebotomine sand fly serve as animal reservoir hosts and vectors, respectively. Despite this, strains of <it>L. (L.) major </it>isolated from many different sources over many years have proved to be relatively uniform. To investigate the population structure of the species highly polymorphic microsatellite markers were employed for greater discrimination among it's otherwise closely related strains, an approach applied successfully to other species of <it>Leishmania</it>.</p> <p>Results</p> <p>Multilocus Microsatellite Typing (MLMT) based on 10 different microsatellite markers was applied to 106 strains of <it>L. (L.) major </it>from different regions where it is endemic. On applying a Bayesian model-based approach, three main populations were identified, corresponding to three separate geographical regions: Central Asia (CA); the Middle East (ME); and Africa (AF). This was congruent with phylogenetic reconstructions based on genetic distances. Re-analysis separated each of the populations into two sub-populations. The two African sub-populations did not correlate well with strains' geographical origin. Strains falling into the sub-populations CA and ME did mostly group according to their place of isolation although some anomalies were seen, probably, owing to human migration.</p> <p>Conclusion</p> <p>The model- and distance-based analyses of the microsatellite data exposed three main populations of <it>L. (L.) major</it>, Central Asia, the Middle East and Africa, each of which separated into two sub-populations. This probably correlates with the different species of rodent host.</p

Distinct Transmission Cycles of Leishmania tropica in 2 Adjacent Foci, Northern Israel

TOC summary for table of contents: Infection with Leishmania tropica is emerging because of encroachment of rock hyraxes and transmission by multiple vector species

Canine leishmaniosis and its relationship to human visceral leishmaniasis in Eastern Uzbekistan

<p>Abstract</p> <p>Background</p> <p>The Namangan Region in the Pap District, located in Eastern Uzbekistan is the main focus of visceral leishmaniasis (VL) in Uzbekistan. In total, 28 cases of human VL were registered during 2006-2008 in this region. A study on the epidemiology of VL in this area was carried out in 2007-2008 in the villages of Chodak, Oltinkan, Gulistan and Chorkesar located at elevations of 900-1200 above sea level.</p> <p>Results</p> <p>A total of 162 dogs were tested for <it>Leishmania </it>infection. Blood was drawn for serology and PCR. When clinical signs of the disease were present, aspirates from lymph nodes and the spleen were taken. Forty-two dogs (25.9%) had clinical signs suggestive of VL and 51 (31.5%) were sero-positive. ITS-1 PCR was performed for 135 dogs using blood and tissue samples and 40 (29.6%) of them were PCR-positive. Leishmanial parasites were cultured from lymph node or spleen aspirates from 10 dogs.</p> <p>Eight <it>Leishmania </it>strains isolated from dogs were typed by multi-locus microsatellite typing (MLMT) and by multilocus enzyme electrophoretic analysis (MLEE), using a 15 enzyme system. These analyses revealed that the strains belong to the most common zymodeme of <it>L. infantum</it>, i.e., MON-1, and form a unique group when compared to MON-1 strains from other geographical regions.</p> <p>Conclusions</p> <p>The data obtained through this study confirm the existence of an active focus of VL in the Namangan region of Uzbekistan. The fact that <it>L. infantum </it>was the causative agent of canine infection with typical clinical signs, and also of human infection affecting only infants, suggests that a zoonotic form of VL similar in epidemiology to Mediterranean VL is present in Uzbekistan.</p

Detection and Identification of Old World Leishmania by High Resolution Melt Analysis

Protozoal parasites of the genus Leishmania are transmitted by sand fly bites to humans and animals. Three major forms of disease are caused by these parasites: cutaneous leishmaniasis, responsible for disfiguring skin wounds; mucocutaneous leishmaniasis, causing non-healing ulceration around the mouth and nose; and the potentially fatal visceral leishmaniasis, involving internal organs such as the spleen and liver. More than 2 million new human infections are caused annually by leishmaniasis globally, it is endemic in more than 88 countries and prevalent also as an imported disease in non-endemic regions due to travel and tourism. Most species of Leishmania that infect humans are zoonotic and transmitted from animal reservoir hosts. As various leishmanial parasites cause disease with similar symptoms, but require different therapeutic regimens and have dissimilar prognoses, reliable, sensitive and rapid diagnostic assays are needed. This study focuses on the five main species that cause leishmaniasis in the Old World. It presents a new assay for rapid detection, species identification and quantification of leishmanial parasites in clinical samples, reservoir hosts and sand flies. This technique could be especially valuable in regions where several leishmanial species exist, in non-endemic regions where infected patients require a rapid diagnosis, and for epidemiological host and vector studies leading to prevention programs

Hipersensibilidad de tipo tardío y proliferación de linfocitos en respuesta a la infección mayor por leishmania en un grupo de niños en Jericó

The cellular response to Leishmania major was evaluated in vitro with a lymphocyte proliferation microtest, performed on 100 ?l of whole blood obtained by finger prick. The maximum time and optimum conditions for storage of fresh blood before testing were determined, and the ability of the assay to evaluate cellular immunity to Leishmania was compared to that of the classical Montenegro skin test. A positive correlation between the diameter of the skin induration and the stimulation index was demonstrated. Defining a positive skin test by induration ?5 mm, and a positive proliferation assay by a stimulation index >2·6 and a response ?3000 ct/min, we found a significant correlation between the 2 tests. The proliferation assay was less sensitive than the skin test, but somewhat more specific. Diagnostic specificities and sensitivities did not differ for the 2 tests

Neighbour Joining tree displaying the phylogenetic relationship between strains of <i>L</i>. <i>aethiopica</i> and <i>L</i>. <i>tropica</i>.

<p>Bootstrap values >50 are indicated at the nodes. For clarity, only the WHO codes of the strains in population Africa/Galilee and of the four ' intermediate ' strains IL/1959, IN/1979, IL/1980, TR/1995 are given. The partial WHO codes specify the host, the country of origin and the year of isolation: I = insect, SER = <i>P</i>. <i>sergenti</i>, ARA = <i>P</i>. <i>arabicus</i>, ROS = <i>P</i>. <i>rossi</i>, M = mammal, PRV = <i>Procavia</i> (hyrax). If not indicated otherwise, the strains were isolated from human cases. The full WHO codes of all the strains are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131227#pone.0131227.s004" target="_blank">S1 Table</a>. The different colours indicate the clustering based on the Bayesian statistical results at the sub-population level for the population Africa/Galilee; the main populations Turkey/old strains/Palestine and Israel/Palestine are in grey and black, respectively.</p