The distinction of pathogenic Vibrio cholerae groups using arbitrarily primed PCR fingerprints

Pathogenic Vibrio cholerae strains were compared by fingerprinting with arbitrarily primed polymerase chain reaction (AP-PCR). They were O1 classical and El Tor strains and recent non-O1 Bengal strains. Ten oligonucleotides from a total of fifty-two tested gave distinctive patterns, and these strains were separated into four groups. A second technique, amplification of 16S/23S rRNA spacers with a pair of oligonucleotides, was also used. Various bands were obtained, and the result can be treated as an additional fingerprint with a different pattern for each of the groups. The method of AP-PCR fingerprinting is fast and sensitive. A test of the stability of the El Tor patterns was done with a set of strains isolated during the present Brazilian epidemics. Examples of AP-PCRs with non-O1 strains are given. A typing scheme is proposed in which oligo 1 is first used, and depending on the fingerprint obtained, additional oligonucleotides are used to confirm the classification of the strain. It is proposed that the AP-PCR technique be used for epidemiological studies, analysing strains reaching new locations or environmental isolates suspected of being pathogenic. It will be particularly helpful in cases in which traditional methods cannot clearly classify the strain.