BECAS
CARRERA PAEZ Laura Camila
congresos y reuniones científicas
Título:
CHARACTERIZATION OF OUTER MEMBRANE VESICLES FROM MULTIDRUG RESISTANT BACTERIA
Autor/es:
CARRERA PÁEZ LAURA CAMILA; MARÍA PAULA QUIROGA; MARTIN OLIVIER; DANIELA CENTRÓN
Lugar:
Buenos aires, CABA
Reunión:
Congreso; Reunion anual de sociedades en biociencias SAIC.SAI.SAFIS. 2020; 2020
Institución organizadora:
Sociedad Argentina de Investigación Clínica
Resumen:
The outer membrane vesicles (OMV) are vesicles that transport, harbor and are able to deliver its content. Among the content that could be found in OMVs, there are genes associated with antimicrobial resistance. In this study we proposed to characterize the OMVs from two extensively resistant clones with epidemic behavior circulating in Argentina, E. coli ST131 (SM5), and P. aeuriginosa ST2867 (PAE981). In addition, we looked for the presence of genes associated with antimicrobial resistance in these vesicles. To characterize OMVs, we used an isolation method that was based on the International Society for Extracellular Vesicles guidelines. This procedure recommends: (i) The source of OMVs must be quantitatively defined, for that reason we adjusted the initial culture of bacteria to OD600 ~ 0.05, (ii) Total quantification of OMVs, in this case we quantified the proteins with the Micro BCA Protein Assay Kit, (iii) A technique that provides images of individual electric vesicles at high resolution, for this we used transmission electron microscopy (TEM), and (iv) It is needed to have evidence of individual particle analysis technique that estimate biophysical characteristics of EVs, for this we used nanoparticle tracking analysis (NTA). Finally, by PCR assay we looked for genes associated with antimicrobial resistance and confirm the result by PCR and sequencing. NTA results showed a typical distribution of peaks for OMVs with a major peak between 100?300 nm in diameter. These results were confirmed through TEM images, where they showed a heterogeneous distribution and particles of similar size to those found in NTA. PCR and sequencing assays allowed us to detect in the OMVs from E. coli ST131 SM5 the blaCTX-M-15 gene, and from P. aeruginosa ST2867 the blaVIM-2 gene. The present study shows an efficient isolation method in different bacterial genera that allows the physical characterization and detection of genes associated with antimicrobial resistance by PCR in OMV.