MOLECULAR SUBTYPING OF VIBRIO-CHOLERAE-01 STRAINS RECENTLY ISOLATED FROM PATIENT, FOOD AND ENVIRONMENTAL-SAMPLES IN SPAIN

Nineteen Vibrio cholerae O1 strains isolated in Spain from patient, fo od and environmental samples in the period 1990-1992 were characterize d by detection of cholera toxin by enzyme immunoassay, detection of ch olera toxin gene by polymerase chain reaction, and by biotyping, ribot yping and pulsed-field gel electrophoresis. Ten isolates were toxigeni c and were further characterized by multilocus enzyme electrophoresis. Molecular subtyping methods allowed precise differentiation between i solates, indicating their geographic origin. Isolates associated with the ongoing seventh pandemic were distinguishable from those associate d with the present Latin American epidemic. All isolates from the envi ronment and seafood were nontoxigenic, and were genetically different and more diverse than toxigenic isolates. The data suggest that a focu s of endemic cholera does not exist in Spain, and that the analyzed no ntoxigenic Vibrio cholerae O1 isolates from imported seafood were not a threat to public health.