Novos iniciadores para detecção de Leishmania infantum pela reação em cadeia da polimerase

Leishmania infantum causes visceral leishmaniasis (VL) in the New World. The diagnosis of VL is confirmed by parasitological and serological tests, which are not always sensitive or specific. Our aim was to design new primers to perform a Polymerase Chain Reaction (PCR) for detecting L. infantum. Sequences of the minicircle kinetoplast DNA (kDNA) were obtained from GenBank, and the FLC2/RLC2 primers were designed. Samples of DNA from L. infantum, Leishmania amazonensis, Leishmania braziliensis, Leishmania guyanensis, Leishmania naiffi, Leishmania lainsoni, Leishmania panamensis, Leishmania major and Trypanosoma cruzi were used to standardize the PCR. PCR with FLC2/RLC2 primers amplified a fragment of 230 bp and the detection limit was 0.2 fg of L. infantum DNA. Of the parasite species assayed, only L. infantum DNA was amplified. After sequencing, the fragment was aligned to GenBank sequences, and showed (99%) homology with L. infantum. In the analysis of blood samples and lesion biopsy from a dog clinically suspected to have VL, the PCR detected DNA from L. infantum. In biopsy lesions from humans and dogs with cutaneous leishmaniasis, the PCR was negative. The PCR with FLC2/RLC2 primers showed high sensitivity and specificity, and constitutes a promising technique for the diagnosis of VL.Leishmania infantum causa leishmaniose visceral (LV) no Novo Mundo. O diagnóstico de LV é confirmado por testes parasitológicos e sorológicos, os quais nem sempre são sensíveis ou específicos. Nosso objetivo foi desenhar novos iniciadores para realizar uma Reação em Cadeia da Polimerase (PCR) para detecção de L. infantum. Sequências do DNA do minicírculo do cinetoplasto (kDNA) foram obtidos do GenBank, e os iniciadores FLC2/RLC2 foram desenhados. Amostras de DNA de L. infantum, Leishmania amazonensis, Leishmania braziliensis, Leishmania guyanensis, Leishmania naiffi, Leishmania lainsoni, Leishmania panamensis, Leishmania major e Trypanosoma cruzi foram usados para padronizar a PCR. PCR com iniciadores FLC2/RLC2 amplificou um fragmento de 230 pb e detectou 0,2 fg de DNA de L. infantum.Das espécies de parasitos analisadas, somente DNA de L. infantum foi amplificado. Após sequenciamento, o fragmento foi analisado no GenBank, que mostrou homologia com L. infantum. Em análises de amostras de sangue e lesão de cão com suspeita clínica de LV, a PCR detectou DNA de L. infantum. Em amostras de lesão de humanos e cães com leishmaniose cutânea, a PCR foi negativa. A PCR padronizada com os iniciadores FLC2/RLC2 mostrou alta sensibilidade e especificidade, sendo técnica promissora para o diagnóstico de LV

AMERICAN CUTANEOUS LEISHMANIASIS WITH UNUSUAL CLINICAL PRESENTATION AND RESPONSE TO TREATMENT

The clinical manifestations and prognosis of cutaneous leishmaniasis (CL) can be influenced by the immune response of the patient and the species of the parasite. A case of atypical clinical presentation of CL, with development of non-characteristic lesions, poor response to therapy, and a long time to resolution is reported. Confirmatory laboratory tests included parasite detection, indirect immunofluorescence, Montenegro skin test, polymerase chain reaction, and parasite identification by multilocus enzyme electrophoresis. The parasite was identified as Leishmaniabraziliensis. The lesion was unresponsive to three complete courses of N-methylglucamine antimoniate intramuscular, and to treatment with pentamidine. The patient did not tolerate amphotericin B. The lesion finally receded after treatment with intravenous N-methylglucamine antimoniate. It is essential to ensure the accuracy of diagnosis and the appropriate treatment, which can include the use a second choice drug or a different route of administration

Photodynamic Therapy for the Treatment of American Tegumentary Leishmaniasis: Evaluation of Therapies Association in Experimentally Infected Mice With Leishmania (Leishmania) amazonensis

Introduction: American tegumentary leishmaniasis (ATL) is a zoonotic disease caused by protozoan parasites of the genus Leishmania that affects the skin and mucous membrane. Currently, the available drugs for the treatment are injectable, with side effects, long-term treatment regimen and there is the possibility of drug resistance. Thus, alternative therapies have been tested, including photodynamic therapy (PDT). We evaluated the efficacy of PDT on its own and associated with the prescribed ATL treatment.Methods: BALB/c mice were infected with Leishmania (Leishmania) amazonensis and divided into 6 groups: Gluc+PDT, treated with Glucantime® and photodynamic therapy (PDT) with methylene blue (MB)/red LED (light-emitting diode); Gluc, treated with Glucantime®; PDT, treated with PDT with MB/red LED; Ampho+PDT, treated with amphotericin and PDT with MB/red LED; Ampho, treated with amphotericin; and control, which were infected but not treated. Two treatment cycles were performed. After 165 days of infection, the parasite load was determined.Results: Statistical differences were not found (P > 0.05) between measures of volume and thickness of the infected footpads in the treated groups when compared with the control group. However, there was a significant reduction (P < 0.05) in the parasitic load of the popliteal lymph nodes of the Gluc+PDT, Gluc, PDT and Ampho groups when compared to the control group. In the histological analysis of the infected footpads, the Gluc+PDT group presented a smaller amount of amastigote nests and lower intensity of the mononuclear infiltrate when compared to the Gluc and PDT groups.Conclusion: The results showed that although there is no significant difference in the evaluations of footpad size (thickness and volume), there is a downward measurement tendency in the Gluc+PDT group, as it can be observed by volume data and corroborated by parasite negative load

Photodynamic Therapy With Bengal Rose and Derivatives Against Leishmania amazonensis

Introduction: The treatment of cutaneous leishmaniasis (CL) is based primarily on the use of pentavalent antimonials, which may lead to many side effects limiting their use. Photodynamic therapy (PDT) is an alternative for the treatment of CL, and some xanthene dyes have the potential for use in PDT.Methods: The xanthenes rose bengal B (RB) and its derivatives rose bengal methyl ester (RBMET), and butyl ester (RBBUT) were analyzed for leishmanicidal activity against promastigotes and intracellular amastigotes of Leishmania amazonensis. Cytotoxicity was assessed in J774.A1 macrophages.Results: RB derivates RBMET (IC50 9.83 μM), and RBBUT (IC50 45.08 μM) showed leishmanicidal activity, however, were toxic to J774.A1 macrophages, resulting in low selectivity index.Conclusion: The RBMET and RBBUT showed to be effective against the L. amazonensis and the low selectivity index presented may not be a limitation for their use in PDT to CL treatment

Nota sobre leishmaniose canina no noroeste do Estado do Paraná, sul do Brasil

In an American cutaneous leishmaniasis endemic area in Jussara county, Paraná State, Brazil, three dogs were found to be infected by Leishmania (Viannia) braziliensis.Em área endêmica de leishmaniose tegumentar americana no Município de Jussara, Estado do Paraná, Brasil, detectaram-se três cães domésticos infectados por Leishmania (Viannia) brasiliensis

Activity of antiretroviral drugs in human infections by opportunistic agents

Highly active antiretroviral therapy (HAART) is used in patients infected with HIV. This treatment has been shown to significantly decrease opportunist infections such as those caused by viruses, fungi and particularly, protozoa. The use of HAART in HIV-positive persons is associated with immune reconstitution as well as decreased prevalence of oral candidiasis and candidal carriage. Antiretroviral therapy benefits patients who are co-infected by the human immunodeficiency virus (HIV), human herpes virus 8 (HHV-8), Epstein-Barr virus, hepatitis B virus (HBV), parvovirus B19 and cytomegalovirus (CMV). HAART has also led to a significant reduction in the incidence, and the modification of characteristics, of bacteremia by etiological agents such as Staphylococcus aureus, coagulase negative staphylococcus, non-typhoid species of Salmonella, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Mycobacterium tuberculosis. HAART can modify the natural history of cryptosporidiosis and microsporidiosis, and restore mucosal immunity, leading to the eradication of Cryptosporidium parvum. A similar restoration of immune response occurs in infections by Toxoplasma gondii. The decline in the incidence of visceral leishmaniasis/HIV co-infection can be observed after the introduction of protease inhibitor therapy. Current findings are highly relevant for clinical medicine and may serve to reduce the number of prescribed drugs thereby improving the quality of life of patients with opportunistic diseases.A terapia HAART (terapia antirretroviral altamente ativa) é usada em pacientes infectados pelo vírus da imunodeficiência humana (HIV) e demonstrou diminuição significativa de infecções oportunistas, tais como as causadas por vírus, fungos, protozoários e bactérias. O uso da HAART está associado com a reconstituição imunológica e diminuição na prevalência de candidíase oral. A terapia antirretroviral beneficia pacientes co-infectados pelo HIV, vírus herpes humano 8 (HHV-8), vírus Epstein-Barr (EBV), vírus da hepatite B (HBV), parvovírus B19 e citomegalovírus (CMV). A HAART também apresentou redução significativa da incidência e modificou as características da bacteremia por agentes etiológicos, tais como Staphylococcus aureus, espécies não-tifóides de Salmonella, Streptococcus pneumoniae, Pseudomonas aeruginosa, Mycobacterium tuberculosis. A HAART é capaz de modificar significativamente a história natural da criptosporidiose e microsporidiose. HAART pode efetivamente restaurar a imunidade da mucosa, levando à erradicação de Cryptosporidium parvum. Semelhante restauração da resposta imune ocorre em infecções por Toxoplasma gondii. O declínio na incidência de co-infecção leishmaniose visceral/HIV pode ser observada após a introdução da terapia com inibidores da protease. Os resultados atuais são altamente relevantes para a medicina clínica e podem proporcionar diminuição no número de prescrições medicamentosas e, consequentemente, melhor qualidade de vida para pacientes com doenças oportunistas