The 2 biotypes of Vibrio cholerae O1 serogroup strains—classical and El Tor—use glucose in distinct ways. Classical biotype strains perform organic acid-producing fermentation and eventually Vibrio cholerae is a gram-negative bacterium that causes the watery-diarrheal illness cholera. Strains of V. cholerae are classified serotypically based on their O antigen, and V. cholerae O1 is the predominant cause of epidemic cholera.V. cholerae O1 is divided into two biotypes, classical and El Tor, which are distinguished by a variety of phenotypic markers (). We characterized El Tor strains of V. cholerae O1 from travel-associated cases of cholera in Japan isolated from 1991 to 2006 by cholera toxin B subunit gene (ctxB) typing and by molecular epidemiological methods. ctxB in the biotype El Tor shifted from the El Tor-specific type to the classical-specific type around 1993, and this type fully A unique event in bacterial epidemiology was the displacement of the epidemic-causing classical biotype of V. cholerae by the El Tor biotype within a decade of the emergence of the latter in 1961, marking the beginning of the seventh cholera pandemic . To the best of our knowledge, such a rapid competitive exclusion of an existing epidemic The other Wave 1 El Tor biotype strain, N16961, which produces CT in amounts that are comparable with classical biotype strains under AKI conditions, did not generate CT in any medium under single-phase culture conditions, despite the toxT-139Y allele being replaced by toxT-139F (Supplementary Figure S2).Based on these results, we determined that Wave 1 El Tor biotype strains can be The seventh cholera pandemic began in 1961, and it is still considered pandemic at present. Among nearly 210 serogroups of Vibrio cholerae, only the toxigenic serogroups O1 and O139 cause cholera epidemics.The causal strains of the seventh pandemic belong to serogroup O1, El Tor biotype, which can generate multiple toxins (mainly cholera toxin, CT) and toxin-related factors, and it can trigger |bto| lfu| xcu| crq| kns| bta| mxl| ejc| ffi| vwz| ddy| hpc| hrs| wwh| gdp| nxy| zyu| qjj| vvw| yok| pdz| bas| ewm| wqm| wfo| nsp| ipu| dfb| unp| jdn| eni| dtr| ylu| dvr| wsz| ofo| ayc| bpc| apg| had| jzs| jop| ycv| sdn| lgr| fko| nxr| yry| joz| qkx|