Rodriguez Tarazona E.,Complejo Asistencial Universitario Of Salamanca |
Garcia Rodriguez J.A.,University of Salamanca |
Munoz Bellido J.L.,Complejo Asistencial Universitario Of Salamanca |
Munoz Bellido J.L.,University of Salamanca |
Munoz Bellido J.L.,Institute Investigacion Biomedica IBSAL
Enfermedades Infecciosas y Microbiologia Clinica | Year: 2015
Aim of the study To determine the activity of fluoroquinolones (FQ) and the selection of FQ-resistant mutants in a macrophage experimental infection model (MEIM). Material and methods Canine macrophages were inoculated with Brucella melitensis ATCC 23457 (WT), achieving intracellular counts of around 105 CFU/mL. Cell cultures were incubated in the presence of ciprofloxacin (CIP), levofloxacin (LEV), moxifloxacin (MOX), and doxycycline (DOX). After cell lysis, surviving microorganisms were plated for count purposes, and plated onto antibiotics-containing media for mutant selection. Topoisomerases mutations were detected by PCR and sequencing. Results Bacterial counts after cell lysis were 14.3% (CIP), 65.3% (LEV), and 75% (MOX) lower compared to the control. Quinolone-resistant mutants emerged in cell cultures containing CIP and LEV with a frequency of around 0.5 × 10-3. All mutants showed an Ala87Val change in GyrA. Mutants had FQs MICs around 10 × WT. The ability of these mutants for infecting new macrophages and the intracellular lysis after antibiotic exposure did not change significantly. No 2nd step FQ-resistant mutants were selected from 1st step mutants. Conclusions Intracellular activity of FQs is low against WT and gyrA-mutant Brucella. FQs easily select gyrA mutants in MEIM. The ability of mutants for infecting new macrophages remains unchanged. In this MEIM, 2nd step mutants do not emerge. © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica.
Vallejo J.A.,University of Santiago de Compostela |
Miranda P.,University of Santiago de Compostela |
Flores-Felix J.D.,University of Salamanca |
Sanchez-Juanes F.,Hospital Universitario Of Salamanca |
And 8 more authors.
Systematic and Applied Microbiology | Year: 2013
Chicha is a drink prepared in several Andean countries from Inca's times by maize fermentation. Currently this fermentation is carried out in familiar artesanal "chicherías" that make one of the most known types of chicha, the "chicha de jora". In this study we isolate and identify the yeasts mainly responsible of the fermentation process in this type of chicha in 10 traditional "chicherías" in Cusco region in Peru. We applied by first time MALDI-TOF MS analysis for the identification of yeast of non-clinic origin and the results showed that all of yeast strains isolated belong to the species Saccharomyces cerevisiae. These results agree with those obtained after the analysis of the D1/D2 and 5.8S-ITS regions. However the chicha strains have a phenotypic profile that differed in more than 40% as compared to that of current S. cerevisiae strains. To the best of our knowledge this is the first report concerning the yeasts involved in chicha fermentation. © 2013 Elsevier GmbH.