To identify naturally infected Lutzomyia spp. by Leishmania (Viannia) braziliensis, a PCR multiplex non-isotopic hybridisation assay was developed for the analysis of insect samples collected in distinct areas of the municipality of Rio de Janeiro (Brazil), from March to December 2003. Data from experimental infection indicate that the method can detect one individual infected insect out of ten. Wild sand flies were classified and grouped into pools of 10 specimens each, reaching a total of 40 female groups. Positive results were obtained with pools of Lu. intermedia (5/32) and Lu. migonei (3/5) collected in two areas from the district of Jacarepaguá presenting recent cases of human and canine leishmaniasis. Considering eight infected groups (8/40) with at least one positive insect in each, it was possible to infer an infection rate of 2%. This technique permits the synchronous processing of a large number of samples, in order to investigate infection rates in sand fly populations and to identify potential insect vectors. The results presented here represent the first molecular approach used to infer the natural infection index in both Lutzomyia spp. and constitute essential data to the understanding of leishmaniasis ecoepidemiology in endemic areas from Rio de Janeiro.
21 September 2020 in Antimicrobial Agents and Chemotherapy
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is already responsible for far more deaths than previous pathogenic coronaviruses (CoVs) from 2002 and 2012. The identification of clinically approved drugs to be repurposed to combat 2019 CoV disease (COVID-19) would allow the rapid implementation of potentially life-saving procedures. The major protease (Mpro) of SARS-CoV-2 is considered a promising target, based on previous results from related CoVs with lopinavir (LPV), an HIV protease inhibitor.
Leishmaniaparasites cause human tegumentary and visceral infections that are commonly referred to as leishmaniasis. Despite the high incidence and prevalence of cases, leishmaniasis has been a neglected disease because it mainly affects developing countries. The data obtained from the analysis of patients’ biological samples and from assays with animal models confirm the involvement of an array of the parasite’s components in its survival inside the mammalian host.These components are classified as virulence factors. In this review, we focus on studies that have explored the role of proteinases as virulence factors that promote parasite survival and immune modulation in the mammalian host. Additionally, the direct involvement of proteinases from the host in lesion evolution is analyzed. The gathered data shows that both parasite and host proteinases are involved in the clinical manifestation of leishmaniasis. It is interesting to note that although the majority of the classes of proteinases are present inLeishmaniaspp., only cysteine-proteinases, metalloproteinases and, to a lesser scale, serine-proteinases have been adequately studied. Members from these classes have been implicated in tissue invasion, survival in macrophages and immune modulation by parasites. This review reinforces the importance of the parasite proteinases, which are interesting candidates for new chemo or immunotherapies, in the clinical manifestations of leishmaniasis.