GENETIC DIVERSITY OF Lutzomyia (Nyssomyia) intermedia IN AN ENDEMIC AREA OF AMERICAN CUTANEOUS LEISHMANIASIS, STATE OF PARANÁ, BRAZIL

Lutzomyia intermedia (Diptera: Psychodidae) features as one of the main vectors that are involved in the transmission of American cutaneous leishmaniasis (ACL) in the Neotropical region. However, genetic studies involving this taxon are still incipient and important for understanding the level of variability of different populations, their role, and implications as vectors. The aim of this study was to determine the level of genetic diversity of L. intermedia present in the Ribeira River Valley, an area of ACL transmission in the state of Paraná, Brazil, through the Random amplified polymorphic DNA (RAPD). Two municipalities were chosen to collect sand flies: Cerro Azul (new transmission area of the ACL) and Adrianópolis (endemic area of the ACL). The insects were captured in the house, in the peridomicile and in the wild (forest). Two of the used markers made it possible to estimate the polymorphism of the studied populations, resulting in 40 genotypes, most of them from peridomicile. The dendrogram generated by the analysis with the primer A10 showed different degrees of similarity, suggesting that there may be gene flow in the studied populations. The Principal Coordinate Analysis (PCO) with the A2 primer, was useful in grouping L. intermedia according to its ecological and geographical origin. There was no distinction between the lineages composing the L. intermedia complex. The results of this study, with the record of great genotypic diversity in L. intermedia, may contribute to explain the maintenance of the life cycle of Leishmania braziliensis (Kinetoplastida: Trypanosomatidae) in the region.

Using Geoprocessing Techniques to Analyze the Geographic Distribution of Lutzomyia (Nyssomyia) Whitmani (Diptera: Psychodidae: Phlebotominae) Associated With Vegetation Cover, and the Impacts on the Expansion of American Cutaneous Leishmaniasis (ACL) In Brazil.

BackgroundIn Brazil, due to new and complex epidemiologic scenarios, the focal and dynamic transmissions of American Cutaneous Leishmaniasis (ACL) occur in different patterns, depending on location. An important example of this phenomenon is the widespread distribution and various behavior patterns of Lutzomyia (Nyssomyia) whitmani, a vector that transmits three types of dermatropic leishmaniases: Leishmania (Viannia) braziliensis, Leishmania (Viannia) shawi and Leishmania (Viannia) guyanensis. This study aims to correlate different types of Brazilian vegetation with the spatial distribution of L. (N.) whitmani in the areas representing Spatial Circuits of Production for American Cutaneous Leishmaniasis (ACL).MethodsIn order to evaluate the ACL vigilance and monitoring model in Brazil, the Ministry of Health has analyzed the Spatial Circuit of the disease until 2013, currently adopting a classification of ACL transmission in municipalities that is based on the composite indicator of tegumentary leishmaniasis (ICLT). For this study, a Geographic Information System (GIS) was used to integrate the layers of L. (N.) whitmani’s geographic distribution with vegetation cover and Spatial Circuits of ACL in Brazilian municipalities.ResultsOut of the 5570 Brazilian municipalities here analyzed, information on the L. (N.) whitmani was found for 862. The vector occurred in nearly all types of vegetation, with a widespread distribution in: Dense Ombrophilous Forests, Open Ombrophilous Forests (or transition forests), Seasonal Decidual Forests (or deciduous woods), Seasonal Semidecidual Forests (semideciduous woods) and Steppe. The vector was not found in Oligotrophic Woody Vegetation of the Marshes and of Sand Accumulation. ConclusionsThis ample presence of the vector reinforces the hypothesis that L. (N.) whitmani is a notable species, that can easily adapt to different environments.

PARTICIPAÇÃO DOS RECEPTORES TOLL-LIKE NA RESPOSTA A INFECÇÃO in vitro POR Leishmania (Viannia) braziliensis: UMA REVISÃO DE LITERATURA

Introdução: A Leishmania braziliensis é um protozoário da família Trypanosomatidae responsável pelo desenvolvimento de uma das formas dermotrópicas da doença denominada leishmaniose mucosa (LM). O parasito é intracelular obrigatório e se multiplica dentro dos macrófagos e monócitos de seus hospedeiros. Os receptores tolllike (TLR) são glicoproteínas transmembrana presentes nas células de defesa, principalmente Natural Killer, macrófagos e células dendríticas, que reconhecem estruturas microbianas e que promovem uma série de sinais que produzem citocinas próinflamatórias importantes para que a resposta imune inata seja efetiva, como por exemplo TNF-α, IL-10 e TGF-β. Objetivo: Realizar revisão da literatura a respeito do papel dos receptores Toll-like na resposta à infecção in vitro por L. braziliensis. Material e métodos: Realizado no formato de revisão integrativa, a pesquisa abrangeu artigos científicos das bases de dados SCIELO e PUBMED. Os descritores utilizados foram “American Cutaneous leishmaniasis”, “Leishmania braziliensis”, “mucosal leishmaniasis” e “Toll-like receptors”. Foram selecionados artigos acadêmicos originais, escritos na língua inglesa, que foram publicados no período de 2014 a 2020, obtendo -se 20 artigos. Após a leitura dos títulos e resumos e ao adotar os critérios de exclusão, foram selecionados 12 artigos originais para a presente revisão. Resultados: As pesquisas selecionadas avaliaram 147 pacientes com diagnóstico histopatológico de Leishmaniose Cutânea (LC). Os pacientes que apresentavam LM, concomitantemente possuíam uma maior expressão de células TCD4+, TCD8+, IL-10+ e TGF-β+ em comparação com aqueles que possuíam LC, que expressavam uma menor quantidades dessas citocinas. Em oposição, o TNF-α em pacientes com LC, encontrava-se aumentado se comparada a LM. Na análise relacionada a TLR-2 e TLR-4, houve uma maior expressão em monócitos nos pacientes com LC associadas a L. braziliensis e que o bloqueio dos TRL reduziu as respostas oxidativas das células de pacientes com LC. Conclusão: Diante dos resultados é possível concluir que a maior expressão de TLR-2 e TLR-4 promove a hiper-reatividade de citocinas pró-inflamatórias e consequente pré-disposição para desenvolvimento da doença. Portanto, seu bloqueio é eficaz para redução das lesões. Esse dado demonstra a relação e o papel dos TLR na infecção por L. braziliensis, trazendo importantes esclarecimentos para a resposta imune e desenho vacinal.

Leishmaniasis: still a diagnostic challenge?

American cutaneous leishmaniasis (ACL) should be differentiated from traumatic ulcers, venous ulcers, tropical ulcer, lower limb ulcers due to sickle cell anemia, pyodermatitis, paracoccidioidomycosis, syphilis, cutaneous neoplasms, among others.1 Histopathology may be suggestive, but it is rarely specific enough to make the diagnosis without identification of the amastigote forms of the parasite.2 Among the non-specific alterations to the histopathological examination, pseudoepitheliomatous hyperplasia (PEH) presents as a challenge, especially in the differential diagnosis with squamous cell carcinoma (SCC).

Persistent cutaneous canine leishmaniasis caused by Leishmania (Viannia) braziliensis in an area with predominance of Nyssomyia neivai in the state of São Paulo, Brazil

American cutaneous leishmaniasis (ACL) is a neglected zoonotic disease caused mainly by Leishmania (Viannia) braziliensis, which is endemic throughout Brazil. Canine ACL cases were investigated in a rural area of Monte Mor, São Paulo, where a human ACL case had been confirmed. Dogs were evaluated through clinical and laboratory diagnosis including serology, cytological tissue preparations and PCR on skin lesions, lymph node and bone marrow samples. Entomological investigations on sandflies trapped in the surroundings of the study area were performed for 14 months. Nyssomyia neivai was the predominant phlebotomine species, comprising 94.65% of the captured specimens (832 out of 879). This species was the most abundant in all trapping sites, including human homes and dog shelters. Ny. whitmani, Migonemyia migonei, Pintomyia monticola, Evandromyia cortellezzii, Pi. fischeri and Expapilata firmatoi were also captured. Two of the three dogs examined were positive for anti-Leishmania IgG in ELISA using the antigen Fucose mannose ligand and skin samples were positive for L. (V.) braziliensis in PCR, but all the samples collected were negative for L. (L.) infantum. One of the dogs had a confirmed persistent infection for more than one year.