Abstract
Objective(s):Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrheal disease in humans, particularly in children under 5 years and travelers in developing countries.To our knowledge, no vaccine is licensed yet to protect against ETEC infection. Like many Gram-negative pathogens, ETEC can secrete outer membrane vesicles (OMVs). These structures contain various immunogenic virulence proteins such as LT and therefore can be used as vaccine candidates. In this study we attempted to isolate the OMVs of ETEC cultivated at different temperatures and evaluate their immunogenicity and protective efficacy in a murine model of infection.Materials and Methods:OMVs was purified from bacterial supernatant by ultracentrifugation. OMVs were encapsulated in chitosan nanoparticles prepared by ionic gelation method within a layer of Eudragit L100 for oral delivery. Female BALB/c mice of 9 weeks’ old were immunized by parenteral injection and oral administration with free and encapsulated OMVs obtained from bacteria cultivated at 37°C and 42°C. The serum samples were collected and the antibody titers were measured by an enzyme-linked immunosorbent assay (ELISA).Results:The protein concentrations of OMVs were 3.47 mg/ml and 2.46 mg/ml for bacteria grown at 37°C and 42°C respectively. OMVs loaded into nanoparticles (NP-OMVs) were homogeneous and spherical in shape, with a size of 532 nm. The encapsulation efficiency of NP was 90%. Mice immunized with OMVs, inhibited the ETEC colonization in their small intestine and induced production of antibodies against LT toxin.Conclusion:The results obtained in this research place OMVs among promising candidates to be used for vaccination.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.