Vesículas de membrana externa (OMVs) extraídas de Escherichia coli e de Klebesiella pneumoniae

Abstract

Gram-negative bacteria are major pathogens that develop antibiotic resistance and cause distinct types of infections. According to the WHO (World Health Organization), bacterial resistance is considered a public health problem. Multiresistance Klebsiella pneumoniae and E. coli are prevalent in many hospitals. These bacteria produce outer membrane vesicles (OMVs) these vesicles can contribute to bacterial survival by eliminating toxic compounds, removing misfolded periplasmic proteins, establishing a colonization niche, biofilm formation, drug delivery, and modulation of host defense and response. This work aimed to evaluate the production and extraction of OMVs produced by E. coli and K. pneumoniae, comparing two different gel filtration and ultracentrifugation methods. Furthermore, we evaluated the interference of OMVs on the growth of enteropathogenic E. coli, uropathogenic E. coli, and hematophatogenic K. pneumoniae strains verifying the viability test. The gel filtration extraction system obtained an elevated concentration when compared to ultracentrifugation method. We observed the presence of OmpA by eletrophoresis and Dot blotting, responsible for the structure of OMVs. The results showed interferences of OMV EC086-UC, EC086-GF and OMV-KP70 on E2348/69 growth were directly proportional to the concentration of OMVs but inversely proportional to the concentration of OMVs with OMV-KP70 on EC086 and KP70 growth. We concluded that vesicle interference on EC086, E2348/69, and KP70 growth should not be based only on optical density parameters but complemented with the viability test of each bacterium strain. The use of biotechnology tools like genetic modifications, OMVs can perform multiple functions carrying molecules with many capabilities to be applied in many fields such as immunology, diagnostics, clinical medicine.