Comparative Analysis of the Composition of Vibrio cholerae O1 El Tor and O139 Vesicle Preparations

The aim of the work was to conduct a comparative study of the composition of preparations made of outer membrane vesicles (OMV) of toxigenic and atoxigenic strains of Vibrio cholerae O1 El Tor and O139 serogroups. Materials and methods . The work used toxigenic and atoxigenic strains of V. cholerae O1 and O139 serogroups, from which OMV preparations were obtained. The structure of OMV preparations was investigated applying transmission electron microscopy. Genome-wide DNA sequencing was performed using the MiSeq and DNB-Seq-g50 platforms. The computer analysis of the obtained data was carried out using the SeqAnalayser 2.1 software. To conduct bioinformatic analysis, the following programs were used: Exonerate version 2.4.0 and SnapGene Viewer. Protein profiling was performed using MALDI-TOF mass spectrometry. The identification of antigenic determinants: cholera toxin and outer membrane proteins (OmpT, OmpU) was carried out by enzyme immunoassay (ELISA). Enzymatic activity was detected using appropriate media and substrates. Fatty acids were indicated through gas chromatography-mass spectrometry. Results and discussion . A comparative analysis of the composition of OMV preparations obtained from toxigenic and atoxigenic V. cholerae O1 and O139 strains has been carried out. The difference/similarity in the composition of OMV preparations has been revealed. According to the data of genome-wide sequencing and bioinformatics analysis, fragments of chromosomes containing a different set of genes and mobile genetic elements were found in OMV preparations obtained from strains with different genotypes. V. cholerae O1 and O139 OMV are able to participate in sorting and docking of cell contents, in vesiculation, contributing to the evolutionary transformations of the genome. OMV may be an additional factor in the pathogenicity/adaptation/persistence/competitiveness of the cholera pathogen.