Excreted Leishmania peruviana and Leishmania amazonensis iron-superoxide dismutase purification: specific antibody detection in Colombian patients with cutaneous leishmaniasis

Diagnostic performance of Leishmania braziliensis and Leishmania peruviana antigens in the immunoblot method for the detection of american tegumentary leishmaniasis

BACKGROUND

Motivation for the study. To contribute to the immunogenic character of soluble and excretion/secretion antigens of Leishmania braziliensis and Leishmania peruviana with the aim of identifying proteins with diagnostic potential.

BACKGROUND

Main findings. The soluble antigen of Leishmania braziliensis has a sensitivity in the detection of ATL of 87.7%, specificity of 100% and a false positive rate of 20% against sera from patients with Chagas disease and 8.3% with mycosis.

BACKGROUND

Implications. Immunoblot can improve the resolution capacity in the serological diagnosis of American tegumentary Leishmaniasis, particularly in patients where the length of the disease and the clinical form make difficult the diagnosis by parasitological methods.

BACKGROUND

This study aimed to determine the performance of Leishmania braziliensis and Leishmania peruviana antigens in the detection of ATL by using serum samples obtained between 2013 - 2016. The obtained soluble and excretion/secretion antigens were transferred to membrane nitrocellulose by immunoblot assay. The evaluation was carried out against sera confirmed for ATL, at a confidence level of 95%, determining that the soluble antigen of Leishmania braziliensis had a sensitivity of 87.7%, specificity of 100% and area under the curve of 0.95; on the other hand, Leishmania peruviana showed values of 92.3%, 95.7% and 0.94, respectively. According to the results, we recommend that the reported immunogenic regions should be characterized and analyzed in order to continue with the development of recombinant and synthetic proteins, aimed at improving the efficiency of the serological diagnosis of the disease.

Potential antigenic targets used in immunological tests for diagnosis of tegumentary leishmaniasis: A systematic review

Immunological tests may represent valuable tools for the diagnosis of human tegumentary leishmaniasis (TL) due to their simple execution, less invasive nature and potential use as a point-of-care test. Indeed, several antigenic targets have been used with the aim of improving the restricted scenario for TL-diagnosis. We performed a worldwide systematic review to identify antigenic targets that have been evaluated for the main clinical forms of TL, such as cutaneous (CL) and mucosal (ML) leishmaniasis. Included were original studies evaluating the sensitivity and specificity of immunological tests for human-TL, CL and/or ML diagnosis using purified or recombinant proteins, synthetic peptides or polyclonal or monoclonal antibodies to detect Leishmania-specific antibodies or antigens. The review methodology followed PRISMA guidelines and all selected studies were evaluated in accordance with QUADAS-2. Thirty-eight original studies from four databases fulfilled the selection criteria. A total of 79 antigens were evaluated for the detection of antibodies as a diagnostic for TL, CL and/or ML by ELISA. Furthermore, three antibodies were evaluated for the detection of antigen by immunochromatographic test (ICT) and immunohistochemistry (IHC) for CL-diagnosis. Several antigenic targets showed 100% of sensitivity and specificity, suggesting potential use for TL-diagnosis in its different clinical manifestations. However, a high number of proof-of-concept studies reinforce the need for further analysis aimed at verifying true diagnostic accuracy in clinical practice.

Molecular Cloning and Biochemical Characterization of Iron Superoxide Dismutase from Leishmania braziliensis

Leishmaniasis is one of the most important neglected tropical diseases, with a broad spectrum of clinical manifestations. Among the clinical manifestations of the disease, cutaneous leishmaniasis, caused by species of Leishmania braziliensis, presents wide distribution in Brazil. In this work, we performed the cloning, expression, and purification of the enzyme superoxide dismutase of Leishmania braziliensis (LbSOD-B2) considered a promising target for the search of new compounds against leishmaniasis. In vitro assays based on pyrogallol oxidation showed that LbSOD-B2 is most active around pH 8 and hydrogen peroxide is a LbSOD-B2 inhibitor at low millimolar range (IC₅₀ = 1 mM).

Presence of trypanosomatid antibodies in gray foxes (Urocyon cinereoargenteus) and domestic and feral dogs (Canis lupus familiaris) in Queretaro, Mexico

Trypanosoma cruzi and Leishmania spp. are vector-borne parasitic protozoa, the causative agents of Chagas and Leishmaniasis diseases, respectively. Trypanosoma cruzi and Leishmania spp. have been reported in a wide variety of mammals, including canids, which play an important role in the transmission of these parasites between urban and natural environments. Currently, no studies have been conducted on trypanosomatids in wild canids in Mexico. Using a partially purified fraction of excreted Iron Superoxide dismutase (FeSODe) of T. cruzi, L. mexicana, and L. infantum as antigen for the ELISA and Western blot tests, we detected the presence of antibodies against these parasites in gray foxes (Urocyon cinereoargenteus Schreber, 1775), domestic and feral dogs (Canis lupus familiaris L.) from Queretaro. Our study provides new information regarding the potential of these carnivores as reservoirs of T. cruzi, Leishmania mexicana, and L. infantum for Latin America.

Purification of a Fe-SOD excreted by Leishmania braziliensis for specific antibodies detection in Mexican human sera: Cutting-edge the knowledge

Clinical diagnosis of leishmaniasis is highly complex, presenting a wide range of clinical manifestations, sometimes non-specific, and thus the epidemiological study and diagnostic need specific molecular markers for each Leishmania species. Leishmania spp. posses different Fe-SOD isoforms, one of which is excreted into the external milieu and, presenting immunogenic characteristics, is a very reliable molecular marker. Superoxide dismutases (SODs) are antioxidant metal-enzymes responsible for the dismutation of superoxide ion into hydrogen peroxide and molecular oxygen, and it is considered an important virulence factor. In this manuscript we have purified the iron(Fe)-SOD excreted by Leishmania braziliensis using ion-exchange and molecular-sieve chromatography and we have studied it as an antigen in serodiagnostic analyses in ELISA and Western blot techniques, testing 213 human sera from Mexico. Indeed, L. braziliensis Fe-SODe has been purified 123.26 times with a specific activity of about 893.66 U/mg of protein. Applying the purified enzymes in serological tests we found 17.84% sera positive. We have demonstrated that the purified enzyme is more sensitive than the non-purified ones and we also demonstrated, for the first time, the presence of antibodies against L. braziliensis, not the main species in the country, in human population from Hidalgo and Nuevo Leon States.