Serogroup Conversion of Vibrio cholerae in Aquatic Reservoirs

摘要: The environmental reservoirs for Vibrio cholerae are natural aquatic habitats, where it colonizes the chitinous exoskeletons of copepod molts. Growth V. on a chitin surface induces competence transformation, mechanism intra-species gene exchange. antigenically diverse O-serogroup determinants encoded by genetically variable biosynthetic cluster genes that is flanked either side chromosomal regions conserved between different serogroups. To determine whether this genomic motif and chitin-induced transformation might enable exchange serogroup-specific clusters O serogroups cholerae, strain O1 El Tor was co-cultured with O139 Bengal within biofilm same immersed in seawater, O1-to-O139 transformants were obtained. Serogroup conversion recipient donor demonstrated comparative hybridization, biochemical serological characterization O-antigenic determinant, resistance to bacteriolysis virulent O1-specific phage. shown have occurred as single-step large fragments DNA. Crossovers localized homology common other flank encoding sequences. This result successful serogroup an O37 DNA indicate be habitats emergence variants better adapted survival niches or more pathogenic humans.