Las bacterias del género Acidithiobacillus son quimiolitotróficas que crecen en ambientes ácidos, especialmente en drenajes ácidos de minas con metales pesados. Aceleran la disolución oxidativa de minerales azufrados facilitando la recuperación de metales de importancia comercial mediante la biolixiviación. Son útiles en la biorremediación de ambientes contaminados con metales tóxicos, como por ejemplo el arsénico, por su capacidad para oxidar y reducir metales. Varias de estas características y otras necesarias para adaptarse a ambientes extremos están codificadas en plásmidos que están relativamente poco estudiados. El objetivo fue caracterizar comparativamente los genomas de los plásmidos de las cepas Acidithiobacillus ferrivorans PQ510 y Acidithiobacillus ferrooxidans PQ506 aisladas de aguas ácidas de zonas mineras de Cerro de Pasco, Perú. Los plásmidos fueron puri...

Dr. Juana María Coha was a professor at the Universidad Nacional Mayor de San Marcos, recognized for her inner energy and intense personality, which could be perceived in her courses and in particular in conversations with her students. With a great desire to promote research and solve problems in the country, it became the guide of many promotions of microbiologists. Juana María Coha Gonzáles, was born on June 24, 1926 in the city of Huacho and died on July 22, 2017. These lines are written by her students and disciples that we continue what she forged in her lines of research.

Dr. Juana María Coha was a professor at the Universidad Nacional Mayor de San Marcos, recognized for her inner energy and intense personality, which could be perceived in her courses and in particular in conversations with her students. With a great desire to promote research and solve problems in the country, it became the guide of many promotions of microbiologists. Juana María Coha Gonzáles, was born on June 24, 1926 in the city of Huacho and died on July 22, 2017. These lines are written by her students and disciples that we continue what she forged in her lines of research.

Carrion's disease, caused by the bacterium Bartonella bacilliformis, is a serious public health problem in Peru, Ecuador and Colombia. Currently there is no available vaccine against B. bacilliformis. While antibiotics are the standard treatment, resistant strains have been reported, and there is a potential spread of the vector that transmits the bacteria. This study aimed to design a multi-epitope vaccine candidate against the causative agent of Carrion's disease using immunoinformatics tools. Predictions of B-cell epitopes, as well as CD4+ and CD8+T cell epitopes, were performed from the entire proteome of B. bacilliformis KC583 using the most frequent alleles from Peru, Ecuador, Colombia, and worldwide. B-cell epitopes and T-cell nested epitopes from outer membrane and virulence-associated proteins were selected. Epitopes were filtered out based on promiscuity, non-allergenicity, con...

Acidithiobacillus ferrivorans is a psychrotolerant acidophile capable of growing and oxidizing ferrous and sulphide substrates at low temperatures. To date, six genomes of this organism have been characterized; however, evidence of a plasmid in this species has been reported only once, whereby there is no conclusive role of the plasmids in the species. Herein, two novel plasmids of A. ferrivorans PQ33 were molecularly characterized and compared at a genomic scale. The genomes of two plasmids (12 kbp and 10 kbp) from A. ferrivorans PQ33 (NZ_LVZL01000000) were sequenced and annotated. The plasmids, named pAfPQ33-1 (NZ_CP021414.1) and pAfPQ33-2 (NZ_CP021415.1), presented 9 CDS and 13 CDS, respectively. In silico analysis showed proteins involved in conjugation (TraD, MobA, Eep and XerD), toxin-antitoxin systems (HicA and HicB), replication (RepA and DNA binding protein), transcription regul...

Acidithiobacillus ferrivorans is a psychrotolerant acidophile capable of growing and oxidizing ferrous and sulphide substrates at low temperatures. To date, six genomes of this organism have been characterized; however, evidence of a plasmid in this species has been reported only once, whereby there is no conclusive role of the plasmids in the species. Herein, two novel plasmids of A. ferrivorans PQ33 were molecularly characterized and compared at a genomic scale. The genomes of two plasmids (12 kbp and 10 kbp) from A. ferrivorans PQ33 (NZ_LVZL01000000) were sequenced and annotated. The plasmids, named pAfPQ33-1 (NZ_CP021414.1) and pAfPQ33-2 (NZ_CP021415.1), presented 9 CDS and 13 CDS, respectively. In silico analysis showed proteins involved in conjugation (TraD, MobA, Eep and XerD), toxin-antitoxin systems (HicA and HicB), replication (RepA and DNA binding protein), transcription regul...

Objetivos: Determinar la actividad antifúngica in vitro del aceite esencial de Citrus paradisi “toronja” sobre cepas de Candida albicans aislados de pacientes con diagnóstico de estomatitis subprotésica. Material y métodos: Se realizaron pruebas de sensibilidad por el método de difusión en agar con pozos. La cepa de Candida albicansse obtuvo de muestras de hisopado de mucosa de pacientes con estomatitis subprotésica y se identifi có por medio de las características morfológicas de sus colonias y la prueba de tubo germinativo. El inóculo fue estandarizado al 0,5 de la escala de Mc Farland y sembrado en 12 placas con agar dextrosa sabouraud. Se hicieron pozos con un sacabocado de 6 mm de diámetro, se depositaron 50 μL de las diferentes concentraciones del aceite esencialy se procedió a la incubación en aerobiosis a 37 °C por 48 horas. El análisis estadístico se r...

Bartonella bacilliformis is the etiologic agent of Carrion's disease, which if endemic to Peru. Studies on antimicrobial resistance genes from clinical isolates of this pathogen are scarce, and the molecular characteristics of these genes and their region resistance-associated are currently unknown. In this work we made the molecular characterization of the quinolone-resistance, and establish the region (QRDR) for the topoisomerase IV, which is encoded by the parC and parE genes, as well as develop an antimicrobial susceptibility test for B. bacilliformis. 65 Blood samples from La Libertad, Cusco, Ancash and Piura were processed on Blood Agar plates and incubated at 30 °C, 5% CO2. The antimicrobial susceptibility was determined, then the genomic DNA extracted, aforementioned genes amplified, their sequence determined and it analyzed using bioinformatics tools. Six positive cultures were...

Bartonella bacilliformis is the etiologic agent of Carrion's disease, which if endemic to Peru. Studies on antimicrobial resistance genes from clinical isolates of this pathogen are scarce, and the molecular characteristics of these genes and their region resistance-associated are currently unknown. In this work we made the molecular characterization of the quinolone-resistance, and establish the region (QRDR) for the topoisomerase IV, which is encoded by the parC and parE genes, as well as develop an antimicrobial susceptibility test for B. bacilliformis. 65 Blood samples from La Libertad, Cusco, Ancash and Piura were processed on Blood Agar plates and incubated at 30 °C, 5% CO2. The antimicrobial susceptibility was determined, then the genomic DNA extracted, aforementioned genes amplified, their sequence determined and it analyzed using bioinformatics tools. Six positive cultures were...

Abstract We designed a 16S rRNA gene PCR-RFLP scheme to identify all currently described Bartonella spp. The 16S rRNA genes of all Bartonella spp. were in-silico analyzed in order to design a RFLP technique able to discriminate among different species. The restriction enzymes selected were MaeIII, MseI, Sau96I, BsaAI, DrdI, FokI, BssHII, BstUI, AluI, TspDTI and HphI which, according to a decision-making tree, facilitated the differentiation of all the currently described species of Bartonella.The technique was experimentally tested in different species of Bartonella, including human pathogenic B. bacilliformis and B. henselae with a 100% of concordance with the in-silico predicted patterns.This novel RFLP assay could be used to identify both human and non-human pathogenic Bartonella in diagnostic, phylogenetic and epidemiologic studies.