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Introduction: The serologic diagnosis of leishmaniosis using total proteins shows cross reactions. The characterization of new Leishmania antigens will improve the use of serological tools for the diagnosis of this disease. Objective: To characterizate a new antigen of Leishmania. Materials and methods: the T166-U19 bacteriophage was characterizated from a cDNA L. (V.) braziliensis library which reacted against pooled sera from patients with cutaneous and mucocutaneous leishmaniasis. The T166-U19 cDNA clone was subcloned in a pGEX plasmid, sequenced, and the recombinant protein was expressed. The reactivity of this recombinant protein was assessed by ELISA. Results: The T166-U19 cDNA clone contained a 318-bp open reading frame (ORF) encoding 105 amino acid residues which has 81,1%, 82,9% and 60,7% identity with L. (L.) infantum LiP, L.(L.) donovani P2, and T. cruzi P2, respectively. Furthermore, the recombinant protein showed low reactivity (50%) with sera from patients with Leishmaniasis and it has croos-reactivity against sera from patients with Chagas disease. Conclusion: the P2__acidic ribosomal protein of L. (V.) braziliensis has been characterized for the first time and it has shown low reactivity against sera from patient with leishmaniasis. [ABSTRACT FROM AUTHOR]

Objective: To standardize a PCR assay for detecting Brucella spp. Materials and methods: Reported primers targeted at the 16S rRNA gene of Brucella were used. Two DNA isolation methods were assessed: phenol-chloroform-isoamyl alcohol method and a commercial kit based on DNA affinity column. Eight Peruvian isolates of Brucella spp. were used to assess sensitivity and 7 different bacterial isolates, including E. coli, Shigella, Proteus mirabilis, Salmonella paratyphi, Salmonella typhi, Citrobacter freundii and Vibrio cholerae were used to assess specificity. Results: Both DNA isolation methods were effective for DNA isolation. The analytical sensitivity of the test was high as we were able to detect at least 80 femtograms of purified DNA. All isolates of Brucella spp. were detected by the assay. Furthermore, the test was negative with 7 bacteria species evaluated in this study. Conclusion: The conditions of a PCR assay to detect Peruvian isolates of Brucella spp, which has been shown to be very sensitive and specific in the laboratory have been standardized. [ABSTRACT FROM AUTHOR]

Objetivo: evaluar la inmunogenicidad de un antígeno multiepitope candidato a vacuna contra la enfermedad de Carrión usando bioinformática. Métodos: estudio básico experimental. Mediante herramientas bioinformáticas se seleccionó segmentos de antígenos de membrana o epítopes del patógeno que interaccionen con MHC clase I y II. Así mismo, se evaluó el grado de toxicidad de los epítopos y su ubicación superficial en la estructura de los antígenos. Con los epítopes seleccionados se diseñó una proteína multi-epitópica, la cual fue sintetizada, clonada y expresada en E. coli BL21. La proteína recombinante fue purificada usando cromatografia de afinidad basada en la resina de Ni-NTA. Ratones BalB/C fueron inmunizados con la proteína multi-epítope y se evaluó los niveles de anticuerpos IgG mediante ELISA indirecto. Resultados: los epítopes seleccionados se unen con MHC clase I y II más prevalentes de la población peruana. Estos epítopes son conservados entre aislamientos de B. bacilliformis. Los epítopes seleccionados se encuentran en la superficie de las proteínas. La proteína multi-epitópica presenta una cobertura poblacional peruana teórica de 99,9%. Esta proteína ha sido clonada, expresada y purificada en E. coli BL21 en condiciones nativas. Asimismo, la proteína es inmunogénica debido a que induce títulos de anticuerpos en ratones inmunizados. Conclusiones: las herramientas bioinformáticas son útiles para el diseño racional de vacunas. La proteína multi-epitópica demostró ser inmunogénica, y puede ser la base de una futura vacuna contra la enfermedad de Carrión. Financiamiento: Este proyecto es financiado por INNOVATEPERU Convenio N° 306-INNOVATEPERU-PIAP-2015. [ABSTRACT FROM AUTHOR]

Objective: Evaluate the association between SNP rs914458 (C>G) of PTPN1 gene with T2DM in a population from the urban area of Lima - Peru. Material and Methods: This study included a total of 216 subjects from the urban area of Lima. The number of subjects in control group was 123, and 93 patients diagnosed with type 2 diabetes from Hospital A. Loayza. SNP genotyping was performed by PCR and sequencing using ABI PRISM 310 DNA sequencer. The association analysis was carried out using the web tool SNPStats and five logistic regression models were performed. The effect of genetic association was established with the OR. Results: The frequency of MAF (allele G) was 0.22 in both control and patient groups. The OR values were not different from the reference values considering the respective confidence interval. Conclusion: No significant association was found between the SNP rs914458 and the PTPN1 gene with T2DM for the urban population of Lima - Peru. [ABSTRACT FROM AUTHOR]