Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Differentiation of the Dimorphic Fungal Species Paracoccidioides brasiliensis and Paracoccidioides lutzii

Isolates of Paracoccidioides brasiliensis and Paracoccidioides lutzii, previously characterized by molecular techniques, were identified for the first time by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). All isolates were correctly identified, with log score values of >2.0. Thus, MALDI-TOF MS is a new tool for differentiating species of the genus Paracoccidioides.Univ São Paulo, Fac Med, Hosp Clin, Cent Lab Div LIM03, São Paulo, BrazilUniv São Paulo, Inst Med Trop, Hosp Clin FMUSP, Lab Med Mycol LIM53, São Paulo, BrazilUniv São Paulo, Dept Biophys, Escola Paulista Med, São Paulo, BrazilUniv Estadual Paulista, Dept Microbiol & Immunol, Inst Biociencias Botucatu, Botucatu, SP, BrazilUniv São Paulo, Dept Biophys, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

Antigenic extracts of Leishmania braziliensis and Leishmania amazonensis associated with saponin partially protects BALB/c mice against Leishmania chagasi infection by suppressing IL-10 and IL-4 production

This study evaluated two vaccine candidates for their effectiveness in protecting BALB/c mice against Leishmania chagasiinfection. These immunogenic preparations were composed of Leishmania amazonensisor Leishmania braziliensisantigenic extracts in association with saponin adjuvant. Mice were given three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of L. chagasiby intravenous injection. We observed that both vaccine candidates induced a significant reduction in the parasite load of the liver, while the L. amazonensisantigenic extract also stimulated a reduction in spleen parasite load. This protection was associated with a suppression of both interleukin (IL)-10 and IL-4 cytokines by spleen cells in response to L. chagasiantigen. No change was detected in the production of IFN-γ. Our data show that these immunogenic preparations reduce the type 2 immune response leading to the control of parasite replication

Antigenic extracts of Leishmania braziliensis and Leishmania amazonensis associated with saponin partially protects BALB/c mice against Leishmania chagasi infection by suppressing IL-10 and IL-4 production

This study evaluated two vaccine candidates for their effectiveness in protecting BALB/c mice against Leishmania chagasi infection. These immunogenic preparations were composed of Leishmania amazonensis or Leishmania braziliensis antigenic extracts in association with saponin adjuvant. Mice were given three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of L. chagasi by intravenous injection. We observed that both vaccine candidates induced a significant reduction in the parasite load of the liver, while the L. amazonensis antigenic extract also stimulated a reduction in spleen parasite load. This protection was associated with a suppression of both interleukin (IL)-10 and IL-4 cytokines by spleen cells in response to L. chagasiantigen. No change was detected in the production of IFN-γ. Our data show that these immunogenic preparations reduce the type 2 immune response leading to the control of parasite replication

Does the Capsule Interfere with Performance of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Cryptococcus neoformans and Cryptococcus gattii?

We described the impact of the capsule size for Cryptococcus neoformans and Cryptococcus gattii identification at the species level by Bruker matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). After experimental capsule size modulation, we observed that reducing the capsule size resulted in improved identification by Bruker MALDI-TOF MS across all of the reference strains analyzed.Univ Sao Paulo, Hosp Clin FMUSP, Med Mycol Lab, LIM 53, Sao Paulo, BrazilUniv Sao Paulo, Inst Trop Med Sao Paulo, LIM 53, Sao Paulo, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Biophys, Sao Paulo, BrazilUniv Sao Paulo, Fac Med, Hosp Clin, Cent Lab Div, LIM 03, Sao Paulo, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Biophys, Sao Paulo, BrazilWeb of Scienc

DNA aptamer selection and construction of an aptasensor based on graphene FETs for Zika virus NS1 protein detection

Zika virus (ZIKV) is a mosquito-borne virus that is phylogenetically close to other medically important flaviviruses with high global public health significance, such as dengue (DENV) and yellow fever (YFV) viruses. Correct diagnosis of a flavivirus infection can be challenging, particularly in world regions where more than one flavivirus co-circulates and YFV vaccination is mandatory. Acid nucleic aptamers are oligonucleotides that bind to a specific target molecule with high affinity and specificity. Because of their unique characteristics, aptamers are promising tools for biosensor development. Aptamers are usually obtained through a procedure called “systematic evolution of ligands by exponential enrichment” (SELEX). In this study, we select an aptamer (termed ZIKV60) by capillary electrophoresis SELEX (CE-SELEX) to the Zika virus non-structural protein 1 (NS1) and counterselection against the NS1 proteins of DENV (serotypes 1, 2, 3, and 4) and YFV. The ZIKV60 dissociation constant (K(d)) is determined by enzyme-linked oligonucleotide assay (ELONA) and the aptamer specificity is evaluated by quantitative real-time polymerase chain reaction. ZIKV60 shows a high binding affinity to the ZIKV NS1 protein with a K(d) value of 2.28 ± 0.28 nM. The aptamer presents high specificity for ZIKV NS1 compared to NS1 of DENV and YFV. Furthermore, graphene field-effect transistor devices functionalized with ZIKV60 exhibit an evident identification of NS1 protein diluted in human serum. These results point to the applicability of biosensors based on the ZIKV60 aptamer for the differential diagnosis of the Zika virus