Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases / Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases

INTRODUCTION: Mucosal leishmaniasis has a progressive course and can cause deformity and even mutilation in the affected areas. It is endemic in the American continent and it is mainly caused by Leishmania (Viannia) braziliensis. OBJECTIVE: To describe a series of mucosal leishmaniasis cases and the infectious Leishmania species. MATERIALS AND METHODS: We included 50 patients with a clinical diagnosis of mucosal leishmaniasis and parasitological confirmation, and we described their clinical and laboratory results. We performed species typing by PCR-RFLP using the miniexon sequence and hsp70 genes; confirmation was done by sequencing. RESULTS: The median time of disease evolution was 2.9 years (range: 1 month to 16 years). The relevant clinical findings included mucosal infiltration (94%), cutaneous leishmaniasis scar (74%), total loss of the nasal septum (24%), nasal deformity (22%), and mucosal ulceration (38%). The symptoms reported included nasal obstruction (90%), epistaxis (72%), rhinorrhea (72%), dysphonia (28%), dysphagia (18%), and nasal pruritus (34%). The histopathological study revealed a pattern compatible with leishmaniasis in 86% of the biopsies, and amastigotes were identified in 14% of them. The Montenegro skin test was positive in 86% of patients, immunofluorescence in 84%, and culture in 8%. Leishmania (V.) braziliensis was identified in 88% of the samples, L. (V) panamensis in 8%, and L. (V.) guyanensis and L. (L.) amazonensis in 2% respectively. CONCLUSION: In this study, we found a severe nasal disease with destruction and deformity of the nasal septum in 25% of the cases, probably associated with late diagnosis. Leishmania (V.) braziliensis was the predominant species. We described a case of mucosal leishmaniasis in Colombia caused by L. (L.) amazonensis for the first time.

Introducción. La leishmaniasis mucosa tiene un curso progresivo y puede causar deformidad e incluso mutilación de las zonas afectadas. Es endémica en el continente americano y es causada principalmente por Leishmania (Viannia) brasiliensis. Objetivo. Describir una serie de casos de leishmaniasis mucosa y las especies de Leishmania infecciosas. Materiales y métodos. Se estudiaron 50 pacientes con diagnóstico clínico de leishmaniasis mucosa y confirmación parasitológica. Se describieron sus características clínicas y los resultados de laboratorio. La tipificación de especies se hizo mediante reacción en cadena de la polimerasa de los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism Polymerase Chain Reaction, PCR-RFLP) en la secuencia del miniexon y el gen hsp70 y se confirmó por secuenciación. Resultados. La evolución de la enfermedad fue de un mes a dieciséis años (mediana de 2,8 años). Los hallazgos clínicos fueron los siguientes: infiltración mucosa (94 %), cicatriz de leishmaniasis cutánea (74 %), pérdida total del tabique nasal (24 %), deformidad nasal (22 %) y ulceración (38 %). Los síntomas reportados fueron: obstrucción nasal (90 %), epistaxis (72 %), rinorrea (72 %), disfonía (28 %), disfagia (18 %) y prurito nasal (34 %). La histopatología mostró un patrón compatible con leishmaniasis en 86 % de las biopsias y se identificaron amastigotes en 14 % de ellas. La prueba de Montenegro fue positiva en 86 % de los pacientes, la inmunofluorescencia en 84 %, y el cultivo en 8 %. Leishmania (V.) brasiliensis se identificó en 88 % de las muestras, L. (V) panamensis en 8 %, y L. (V.) guyanensis y L. (L.) amazonensis en 2 %, respectivamente. Conclusión. Se encontró enfermedad nasal grave con destrucción y deformidad del tabique nasal en una cuarta parte de los casos, probablemente debido a un diagnóstico tardío. Leishmania (V.) brasiliensis fue la especie predominante. Se describe por primera vez un caso de leishmaniasis mucosa causado por L. (L.) amazonensis en Colombia.

Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases / Leishmaniasis mucosa: una enfermedad olvidada, descripción e identificación de especies en 50 casos colombianos

Abstract Introduction: Mucosal leishmaniasis has a progressive course and can cause deformity and even mutilation in the affected areas. It is endemic in the American continent and it is mainly caused by Leishmania (Viannia) braziliensis. Objective: To describe a series of mucosal leishmaniasis cases and the infectious Leishmania species. Materials and methods: We included 50 patients with a clinical diagnosis of mucosal leishmaniasis and parasitological confirmation, and we described their clinical and laboratory results. We performed species typing by PCR-RFLP using the miniexon sequence and hsp70 genes; confirmation was done by sequencing. Results: The median time of disease evolution was 2.9 years (range: 1 month to 16 years). The relevant clinical findings included mucosal infiltration (94%), cutaneous leishmaniasis scar (74%), total loss of the nasal septum (24%), nasal deformity (22%), and mucosal ulceration (38%). The symptoms reported included nasal obstruction (90%), epistaxis (72%), rhinorrhea (72%), dysphonia (28%), dysphagia (18%), and nasal pruritus (34%). The histopathological study revealed a pattern compatible with leishmaniasis in 86% of the biopsies, and amastigotes were identified in 14% of them. The Montenegro skin test was positive in 86% of patients, immunofluorescence in 84%, and culture in 8%. Leishmania (V.) braziliensis was identified in 88% of the samples, L. (V) panamensis in 8%, and L. (V.) guyanensis and L. (L.) amazonensis in 2% respectively. Conclusion: In this study, we found a severe nasal disease with destruction and deformity of the nasal septum in 25% of the cases, probably associated with late diagnosis. Leishmania (V.) braziliensis was the predominant species. We described a case of mucosal leishmaniasis in Colombia caused by L. (L.) amazonensis for the first time.

Resumen Introducción. La leishmaniasis mucosa tiene un curso progresivo y puede causar deformidad e incluso mutilación de las zonas afectadas. Es endémica en el continente americano y es causada principalmente por Leishmania (Viannia) brasiliensis. Objetivo. Describir una serie de casos de leishmaniasis mucosa y las especies de Leishmania infecciosas. Materiales y métodos. Se estudiaron 50 pacientes con diagnóstico clínico de leishmaniasis mucosa y confirmación parasitológica. Se describieron sus características clínicas y los resultados de laboratorio. La tipificación de especies se hizo mediante reacción en cadena de la polimerasa de los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism Polymerase Chain Reaction, PCR-RFLP) en la secuencia del miniexon y el gen hsp70 y se confirmó por secuenciación. Resultados. La evolución de la enfermedad fue de un mes a dieciséis años (mediana de 2,8 años). Los hallazgos clínicos fueron los siguientes: infiltración mucosa (94 %), cicatriz de leishmaniasis cutánea (74 %), pérdida total del tabique nasal (24 %), deformidad nasal (22 %) y ulceración (38 %). Los síntomas reportados fueron: obstrucción nasal (90 %), epistaxis (72 %), rinorrea (72 %), disfonía (28 %), disfagia (18 %) y prurito nasal (34 %). La histopatología mostró un patrón compatible con leishmaniasis en 86 % de las biopsias y se identificaron amastigotes en 14 % de ellas. La prueba de Montenegro fue positiva en 86 % de los pacientes, la inmunofluorescencia en 84 %, y el cultivo en 8 %. Leishmania (V.) brasiliensis se identificó en 88 % de las muestras, L. (V) panamensis en 8 %, y L. (V.) guyanensis y L. (L.) amazonensis en 2 %, respectivamente. Conclusión. Se encontró enfermedad nasal grave con destrucción y deformidad del tabique nasal en una cuarta parte de los casos, probablemente debido a un diagnóstico tardío. Leishmania (V.) brasiliensis fue la especie predominante. Se describe por primera vez un caso de leishmaniasis mucosa causado por L. (L.) amazonensis en Colombia.

Curvas de fusión de regiones genómicas específicas: una herramienta prometedora para el diagnóstico y tipificación de las especies causantes de la leishmaniasis cutánea en Colombia / High-resolution melting analysis based on specific genomic regions: A promising tool for the diagnosis and typing of species causing cutaneous leishmaniasis in Colombia

Resumen Introducción. La leishmaniasis cutánea es una enfermedad causada por parásitos del género Leishmania que tiene gran incidencia en Colombia. El diagnóstico y la identificación de la especie infecciosa son factores críticos en el momento de escoger e iniciar el tratamiento. Actualmente, los métodos de diagnóstico y tipificación requieren procedimientos complejos, por lo que es necesario validar nuevos marcadores moleculares y métodos que simplifiquen el proceso. Objetivo. Desarrollar una herramienta basada en la reacción en cadena de la polimerasa (PCR) con curvas de fusión (High Resolution Melting; PCR-HRM) para el diagnóstico y tipificación de las tres especies de Leishmania de importancia epidemiológica en casos de leishmaniasis cutánea en Colombia. Materiales y métodos. Los genomas de Leishmania panamensis, L. braziliensis y L. guyanensis se compararon mediante métodos bioinformáticos. Las regiones específicas de especie identificadas se validaron mediante PCR. Para los marcadores seleccionados se diseñó una PCR-HRM y se estimaron algunos parámetros de validez y seguridad usando aislamientos de pacientes colombianos caracterizados previamente mediante PCR y análisis de polimorfismos en la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism - RFLP; PCR-RFLP) del gen hsp70. Resultados. El análisis genómico comparativo mostró 24 regiones específicas de especie. Sin embargo, la validación mediante PCR solo identificó un marcador específico para cada especie de Leishmania. Los otros marcadores mostraron amplificación cruzada. El límite de detección para los tres marcadores seleccionados fue de un parásito, mientras que la sensibilidad, la especificidad, el valor predictivo positivo y el negativo fueron de 91,4, 100, 100 y 75 %, respectivamente. Conclusiones. Las tres regiones seleccionadas pueden emplearse como marcadores moleculares en el diagnóstico y tipificación de las especies causantes de la leishmaniasis cutánea en Colombia.

Abstract Introduction: Cutaneous leishmaniasis, caused by parasites of the genus Leishmania, is a disease with high incidence in Colombia. The diagnosis and identification of the infectious species are critical factors when selecting and initiating treatment. Currently, the methods for diagnosing and typing cutaneous leishmaniasis require complicated procedures and there is a need for the validation of new molecular markers and methods to simplify the process. Objective: To develop a tool based in PCR melting curves (PCR-HRM) for the diagnosis and typing of the three Leishmania species of epidemiological importance for cutaneous leishmaniasis in Colombia. Materials and methods: The genomes of Leishmania panamensis, L. braziliensis and L. guyanensis were compared with bioinformatic methods. The species-specific regions were then validated using PCR. For the selected markers, a PCR-HRM was designed, and validity and security parameters were estimated using isolates from Colombian patients previously characterized by PCR-RFLP of the hsp70 gene. Results: The comparative genomic analysis yielded 24 species-specific regions. However, the PCR validation identified only one marker that was specific to each Leishmania species. The other markers showed cross amplification. The detection limit for the three selected markers was one parasite. The sensitivity, specificity, predictive positive and negative values were 91.4%, 100%, 100% and 75%, respectively. Conclusions: The three selected regions can be used as molecular markers in the diagnosis and typing of the causative species of cutaneous leishmaniasis in Colombia.

Evaluation of a Multilocus Sequence Typing (MLST) scheme for Leishmania (Viannia) braziliensis and Leishmania (Viannia) panamensis in Colombia.

BACKGROUND: Leishmaniases are parasitic vector-borne diseases affecting more than 12 million people in 98 countries. In Colombia, leishmaniasis is widespread and the most common clinical manifestation is cutaneous, mainly caused by L. panamensis and L. braziliensis. Currently, the genetic diversity of these species in Colombia is unknown. To address this, we applied molecular techniques for their characterization, using multilocus sequence typing (MLST) to explore the genetic variability and phylodynamics of the disease. METHODS: Seven previously described genetic markers were selected highlighting the implementation of a mitochondrial marker. Markers were applied to 163 samples from isolates obtained between 1980 and 2001. RESULTS: The identification of the samples showed an excellent correlation with typing tests previously applied (MLEE, monoclonal antibodies). Isolates of L. braziliensis showed greater genetic diversity than L. panamensis, and a greater number of diploid sequence types (DSTs). In addition, the geographical distribution of DSTs for each species were obtained through georeferencing maps. CONCLUSIONS: To our knowldge, this study represents the first description of the genetic variability of L. panamensis in Colombia and South America, and is the first to propose a scheme of MLST for epidemiological surveillance of leishmaniasis in the country.

Curvas de fusión de regiones genómicas específicas: una herramienta prometedora para el diagnóstico y tipificación de las especies causantes de la leishmaniasis cutánea en Colombia.

Introducción. La leishmaniasis cutánea es una enfermedad causada por parásitos del género Leishmania que tiene gran incidencia en Colombia. El diagnóstico y la identificación de la especie infecciosa son factores críticos en el momento de escoger e iniciar el tratamiento. Actualmente, los métodos de diagnóstico y tipificación requieren procedimientos complejos, por lo que es necesario validar nuevos marcadores moleculares y métodos que simplifiquen el proceso.Objetivo. Desarrollar una herramienta basada en la reacción en cadena de la polimerasa (PCR) con curvas de fusión (High Resolution Melting; PCR-HRM) para el diagnóstico y tipificación de las tres especies de Leishmania de importancia epidemiológica en casos de leishmaniasis cutánea en Colombia.Materiales y métodos. Los genomas de Leishmania panamensis, L. braziliensis y L. guyanensis se compararon mediante métodos bioinformáticos. Las regiones específicas de especie identificadas se validaron mediante PCR. Para los marcadores seleccionados se diseñó una PCR-HRM y se estimaron algunos parámetros de validez y seguridad usando aislamientos de pacientes colombianos caracterizados previamente mediante PCR y análisis de polimorfismos en la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism - RFLP; PCR-RFLP) del gen hsp70.Resultados. El análisis genómico comparativo mostró 24 regiones específicas de especie. Sin embargo, la validación mediante PCR solo identificó un marcador específico para cada especie de Leishmania. Los otros marcadores mostraron amplificación cruzada. El límite de detección para los tres marcadores seleccionados fue de un parásito, mientras que la sensibilidad, la especificidad, el valor predictivo positivo y el negativo fueron de 91,4, 100, 100 y 75 %, respectivamente.Conclusiones. Las tres regiones seleccionadas pueden emplearse como marcadores moleculares en el diagnóstico y tipificación de las especies causantes de la leishmaniasis cutánea en Colombia.

Calmodulin Polymerase Chain Reaction-Restriction Fragment Length Polymorphism for Leishmania Identification and Typing.

A precise identification of Leishmania species involved in human infections has epidemiological and clinical importance. Herein, we describe a preliminary validation of a restriction fragment length polymorphism assay, based on the calmodulin intergenic spacer region, as a tool for detecting and typing Leishmania species. After calmodulin amplification, the enzyme HaeIII yielded a clear distinction between reference strains of Leishmania mexicana, Leishmania amazonensis, Leishmania infantum, Leishmania lainsoni, and the rest of the Viannia reference species analyzed. The closely related Viannia species: Leishmania braziliensis, Leishmania panamensis, and Leishmania guyanensis, are separated in a subsequent digestion step with different restriction enzymes. We have developed a more accessible molecular protocol for Leishmania identification/typing based on the exploitation of part of the calmodulin gene. This methodology has the potential to become an additional tool for Leishmania species characterization and taxonomy.

Phenotypic characterization of Leishmania spp. causing cutaneous leishmaniasis in the lower Amazon region, western Pará state, Brazil, reveals a putative hybrid parasite, Leishmania (Viannia) guyanensis × Leishmania (Viannia) shawi shawi.

We phenotypically characterized 43 leishmanial parasites from cutaneous leishmaniasis by isoenzyme electrophoresis and the indirect immunofluorescence antibody test (23 McAbs). Identifications revealed 11 (25.6%) strains of Leishmania (V.) braziliensis, 4 (9.3%) of L. (V.) shawi shawi, 7 (16.3%) of L. (V.) shawi santarensis, 6 (13.9%) of L. (V.) guyanensis and L. (V.) lainsoni, 2 (4.7%) of L. (L.) amazonensis, and 7 (16.3%) of a putative hybrid parasite, L. (V.) guyanensis/L. (V.) shawi shawi. McAbs detected three different serodemes of L. (V.) braziliensis: I-7, II-1, and III-3 strains. Among the strains of L. (V.) shawi we identified two populations: one (7 strains) expressing the B19 epitope that was previously considered to be species-specific for L. (V.) guyanensis. We have given this population sub-specific rank, naming it L. (V.) s. santarensis. The other one (4 strains) did not express the B19 epitope like the L. (V.) shawi reference strain, which we now designate as L. (V.) s. shawi. For the first time in the eastern Brazilian Amazon we register a putative hybrid parasite (7 strains), L. (V.) guyanensis/L. (V.) s. shawi, characterized by a new 6PGDH three-band profile at the level of L. (V.) guyanensis. Its PGM profile, however, was very similar to that of L. (V.) s. shawi. These results suggest that the lower Amazon region - western Pará state, Brazil, represents a biome where L. (V.) guyanensis and L. (V.) s. shawi exchange genetic information.

A battery of 12 microsatellite markers for genetic analysis of the Leishmania (Viannia) guyanensis complex.

We used 12 microsatellite markers developed for Leishmania braziliensis to genotype 28 strains of the main species of the Leishmania guyanensis complex (i.e. L. guyanensis and L. panamensis) collected in Ecuador and Peru. The important heterozygote deficits observed in these populations are similar with the previous data obtained in L. braziliensis and raise again the debate on the reproductive mode of these protozoan parasites. The data showed genetic polymorphism and geographical differentiation giving information on population structure of the L. guyanensis complex. Regarding the two species, this study enhances again the debate on the taxonomic status of the different isolates belonging to L. guyanensis s.l. since the results showed substantial heterogeneity within this species complex. In conclusion, this study increases the number of available microsatellite loci for L. guyanensis species complex and raises fundamental biological questions. It confirms that microsatellite markers constitute good tools for population genetic studies on parasites of this complex.

Differentiation of Leishmania (Viannia) panamensis and Leishmania (V.) guyanensis using BccI for hsp70 PCR-RFLP.

Leishmania panamensis and Leishmania guyanensis are two species of the subgenus Viannia that are genetically very similar. Both parasites are usually associated with cutaneous leishmaniasis, but also have the potential to cause the mucocutaneous form of the disease. In addition, the study of foci and consequently the identification of vectors and probable reservoirs involved in transmission require a correct differentiation between both species, which is important at epidemiological level. We explored the possibility of identifying these species by using restriction fragment length polymorphisms (RFLP) in the gene coding for heat-shock protein 70 (hsp70). Previously, an hsp70 PCR-RFLP assay proved to be very effective in differentiating other Leishmania species when HaeIII is used as restriction enzyme. Based on hsp70 sequences analysis, BccI was found to generate species-specific fragments that can easily be recognized by agarose gel electrophoresis. Using the analysis of biopsies, scrapings, and parasite isolates previously grouped in a cluster comprising both L. panamensis and L. guyanensis, we showed that our approach allowed differentiation of both entities. This offers the possibility not only for identification of parasites in biological samples, but also to apply molecular epidemiology in certain countries of the New World, where several Leishmania species could coexist.

Molecular identification of the parasites causing cutaneous leishmaniasis on the Caribbean coast of Colombia.

All clinical manifestations of leishmaniasis exist in Colombia, the cutaneous form being the most frequent in the department of Sucre, where the Leishmania species associated with cutaneous leishmaniasis (CL) is unknown. This study was carried out to determine which Leishmania species was responsible for CL in Sucre, based on amplification and sequencing of the Cyt b gene. Isolates of Leishmania were obtained after CL diagnosis of eight patients who received attention in several health care centers of the study area. The nucleotide sequences obtained from patients were compared to Leishmania reference strains and six of the isolates identified as Leishmania (Viannia) braziliensis, the remaining two being identified as Leishmania (Viannia) panamensis and Leishmania (Viannia) guyanensis. This represents the first report of the presence of L. (V.) guyanensis on the Caribbean coast of Colombia.

Epidemiology of cutaneous leishmaniasis in Suriname: a study performed in 2006.

Cutaneous leishmaniasis (CL) is a widespread disease in Suriname caused by Leishmania Viannia guyanensis. It is argued that other Leishmania species are also responsible for CL and that the incidence is increasing. This study aimed to identify the species causing the disease and to estimate the annual detection rate of CL in Suriname in 2006. In Paramaribo, 152 patients were registered, of whom 33 were tested in two polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) methods. Twenty-seven patients were infected with L. (V.) guyanensis (complex), one with L. (V.) lainsoni, and one with L. (Leishmania) amazonensis. In the hinterland, 162 CL suspected patients were registered by questionnaires; of these, 24 of 27 tested positive by PCR-RFLP (88.9%; 95% CI, 77.1-100%). With extrapolation of collected data, a detection rate was calculated of 5.32 to 6.13 CL patients per 1,000 inhabitants for the hinterland and 0.64 to 0.74 patients per 1,000 inhabitants for the whole country.

Molecular epidemiology of Leishmania (Viannia) guyanensis in French Guiana.

Little information is available about the genetic variability of Leishmania populations and the possible correlations with ecoepidemiological features of leishmaniases. The present study was carried out in French Guiana, a country where cutaneous leishmaniases (CL) are endemic over the whole territory. The genetic polymorphism of a nuclear sequence encompassing the end of the ribosomal small subunit and the internal transcribed spacer 1 of 265 isolates from patients with CL was examined by restriction fragment length polymorphism analysis. Genotypes based on the fingerprinting phenetic integration were compared to epidemiological, clinical, and geographical data. In agreement with previous reports, five different Leishmania species were identified, but Leishmania (Viannia) guyanensis represented 95.8% of the samples. Two distinct L. (V.) guyanensis populations were found to originate in two ecologically characterized regions. Higher lesional parasite densities and the need for additional treatments were significantly linked to genotype group I. Parasites of genotype group II were more likely to cause chronic and disseminated cutaneous forms in patients. L. (V.) guyanensis was previously said not to be very polymorphic; however, the present analysis resulted in a significant degree of discrimination among L. (V.) guyanensis isolates from diverse ecological areas and with different clinical implications.

The rarity of infection with Leishmania (Viannia) braziliensis among patients from the Manaus region of Amazonas state, Brazil, who have cutaneous leishmaniasis.

The frequency of Leishmania ( Viannia) braziliensis infection was assessed in 79 of the 138 patients with cutaneous leishmaniasis who attended a reference outpatient unit in Manaus, Amazonas state, between the August and December of 1997. The disease was characterized by one or more cutaneous ulcers, the skin lesions being frequently associated with satellite lymph-node enlargement. All parasite isolates were identified using monoclonal antibodies and enzyme electrophoresis. Only two (2.8%) of the 71 patients from whom parasites were successfully isolated were found to be infected with L. ( V.) braziliensis, the other 69 isolates being identified, from their isoenzyme profiles, as L. ( V.) guyanensis. In the Manaus region, therefore, almost all human cutaneous leishmaniasis is the result of infection with L. (V.) guyanensis, and L. ( V.) braziliensis is a relatively rare cause of the disease.

Identification of antigenically distinct populations of Leishmania (Viannia) guyanensis from Manaus, Brazil, using monoclonal antibodies.

Eighty Leishmania isolates from patients who contracted cutaneous leishmaniasis in the Manaus region, Amazonas State, Brazil, were identified as Leishmania (Viannia) guyanensis by the electrophoretic profiles of six enzymes. None reacted with the species-specific monoclonal antibody B19. Two L. (V.) guyanensis subpopulations were detected with the monoclonals B2 and B12. The lack of B19 expression by the L. (V.) guyanensis strains in the present study contrasts with that of the vast majority of the strains of the same parasite from eastern Amazonia and French Guyana that express the epitope.

Attempt to differentiate Leishmania (Leishmania) amazonensis, L. (L.) chagasi, Leishmania (Viannia) braziliensis and L. (V.) guyanensis using the SSR-PCR technique.

The ability to differentiate reference strains of Leishmania (Leishmania) amazonensis, L. (L.) chagasi, Leishmania (Viannia) braziliensis and L. (V.) guyanensis was evaluated using the simple sequence repeat polymerase chain reaction (SSR-PCR) technique. This technique differentiates the Leishmania species, generating distinct DNA amplicon profiles. The SSR-PCR profiles were similar to but more reproducible than those produced by RAPD. SSR-PCR is presented as an alternative to other molecular methods for the differentiation of Leishmania species or strains.

Leishmaniose tegumental americana com extenso acometimento de mucosas: relato de caso e revisäo da literatura / American diffuse leishmaniosis with extensive attacking of mucous membranes: case report and literature review

A leishmaniose tegumentar americana é uma doença de evolução crônica que acomete, isoladamente ou em associação, a pele e as mucosas do nariz, boca, faringe e laringe (4). É causada por protozoários do gênero Leishmania e transmitida por insetos do gênero flebotomíneos. Os autores fazem uma revisão bibliográfica e relatam um caso de leishmaniose mucocutânea em um paciente de 26 anos, que apresentava lesão no palato duro e toda orofaringe, evoluindo com emagrecimento importante. A lesão foi diagnosticada através de biópsia de mucosa, a qual evidenciou o protozoário. O interesse do relato se dá pela ascensão do número de casos de leishmaniose em nosso meio, sendo importante o diagnóstico diferencial

Leishmania (Viannia) guyanensis: a new minicircle class exclusive to this specie isolated from a DNA cosmid library useful for taxonomic purposes.

A new minicircle class exclusive to this specie isolated from a DNA cosmid library useful for taxonomic purposes. Experimental Parasitology 94, 143-149. In this paper we describe a new minicircle class exclusive to Leishmania (Viannia) guyanensis. The minicircle class was obtained with the aid of a total DNA cosmid library. The library was screened with an EcoRI fragment isolated from L. (V.) guyanensis (M4147). After screening seven clones were selected which showed strong hybridisation. Clones were digested and hybridised with the same probe. After hybridisation only one clone containing the desired fragment was positive. The fragment sized around 1000 bp was subcloned into pBluescript for sequencing. Sequence analysis using the GCG programme showed no substantial homology with any sequences previously reported, apart from the expected homology with the conserved region of Leishmania kDNA sequences. The probe hybridised strongly only to L. (V.) guyanensis kDNA after medium stringency washing.

Genetic analysis of leishmania parasites in Ecuador: are Leishmania (Viannia) panamensis and Leishmania (V.) Guyanensis distinct taxa?

In the course of an epidemiologic survey in Ecuador, the following collection of Leishmania stocks was isolated: 28 from patients with clinical signs of leishmaniasis, 2 from sloths, 1 from a dog, and 4 from sand flies. For genetic characterization of these stocks, multilocus enzyme electrophoresis (MLEE) and random amplified polymorphic DNA (RAPD) were used. Twenty six of the 35 stocks were identified as either Leishmania (V.) panamensis or L. (V.) guyanensis, 2 stocks were identified as L. (V.) braziliensis, the 2 stocks from sloths showed specific genotypes, and 5 stocks were characterized as hybrids between L. (V.) braziliensis and L. (V.) guyanensis. These data show that genetic diversity of Leishmania in Ecuador is high and that L. (V.) panamensis/guyanensis is the dominant group in this country. The genetic analysis questioned the distinctness between the two species L.(V.) panamensis and L. (V.) guyanensis, since MLEE and RAPD data did not indicate that L. (V.) panamensis and L. (V.) guyanensis correspond to distinct monophyletic lines. Population genetic analysis performed on the L. (V.) panamensis/guyanensis group favors the hypothesis of a basically clonal population structure.