Comparison of Vibrio cholerae serotype 01 strains isolated from patients and the aquatic environment

Vibrio cholerae 01 strains of El Tor and Classical biotypes and Ogawa and Inaba serotypes were isolated from both patients and pond water, the latter used by the patients from whom the V. cholerae 01 strains had been isolated. Paired strains, i.e. from the patient and from the pond used by the patient, were compared. All strains were found to be non-hydrophobic and agglutinating in ammonium sulphate (2.0-2.5 M). They demonstrated similar antibiogram patterns and plasmids were not detected. Except for one clinical and one environmental strain, all strains caused fluid accumulation in the rabbit ileal loop (RIL). The outer membrane protein profiles of both clinical and environmental strains were nearly identical, except for the presence of an additional 22 kDa polypeptide, observed only in environmental strains. The protein profiles of two environmental isolates, analysed after passage through rabbits by oral feeding, were altered, demonstrating a significant decrease in the number of protein bands after animal passage but with the major protein band pattern remaining unchanged. Each passaged strain, however, demonstrated properties similar to the non-passaged culture in cell surface hydrophobicity, plasmid profile, antibiogram patterns, and enterotoxin production.