Vibrio cholerae serogroup O5 was responsible for the outbreak of gastroenteritis in Czechoslovakia in 1965

Abstract

Several authors have attributed the explosive outbreak of gastroenteritis that occurred in Czechoslovakia in 1965 to a toxigenic strain of Vibrio cholerae serogroup O37 based on unverified metadata associated with three particular strains from the American Type Culture Collection. Here, by sequencing the original strain preserved at the Czech National Collection of Type Cultures since 1966, we show that the strain responsible for this outbreak was actually a V. cholerae O5 that lacks the genes encoding the cholera toxin, the toxin-coregulated pilus protein and Vibrio pathogenicity islands present in V. cholerae O37 strains.

Keywords: 1965; Czechoslovakia; O5; Vibrio cholerae; gastroenteritis.

Fig. 1.. Maximum likelihood phylogeny of 388 Vibrio genomes, including V. cholerae CNCTC 6536 (= NCV 10125). Three Vibrio genomes belonging to non-V. cholerae species (07–2435, RC341 and RC586) were used as the outgroup (brown). The colour coding of the ring indicates the serogroup of the isolates. Lineages are named according to previous reports [2233]. A scale bar indicates the number of nucleotide substitutions per variable site. A magnification of clades containing serogroups O5 and O37 (a and b, respectively) is shown on the right. In panels a and b, the name, country and year of isolation are indicated for each genome at the tips (in green for serogroup O5 strains and in blue for O37) and the bootstrap values ≥90 % are shown in red.