The O139 serogroup of Vibrio cholerae comprises diverse clones of epidemicand nonepidemic strains derived from multiple V. cholerae O1 or non-O1 progenitors

Sixty-four representative strains of Vibrio cholerae O139 were analyzed, to re-examine the origin of this serogroup, Ribotyping differentiated the str ains into 3 HindIII and 7 BglI ribotypes, One HindIII and 5 BglI ribotypes were shared by all toxigenic O139 strains. Of 6 nontoxigenic O139 strains, 3 shared ribotypes with the toxigenic strains, carried genes encoding toxin coregulated pilus, and were susceptible to the cholera toxin-converting ba cteriophage CTX Phi. The remaining 3 strains belonged to 2 different riboty pes distinct from toxigenic O139 strains and were resistant to CTX Phi, and JA-1, an O139-specific lytic bacteriophage, Polymerase chain reaction ampl icons corresponding to the gmhD gene carried by these 3 strains also differ ed from those of the toxigenic O139 strains but were identical to those of 15 environmental non-O1-non-O139 strains. Thus, the O139 antigen is present in different lineages, and this serogroup appears to comprise epidemic and nonepidemic strains derived separately from different progenitors.