Comparison of four typing methods for Aeromonas species.

Abstract

The relative sensitivities of multi-locus enzyme electrophoresis, restriction endonuclease analysis, ribosomal DNA typing, and phage typing, in distinguishing between epidemiologically unrelated Aeromonas isolates were compared. All strains were typable by multi-locus enzyme electrophoresis, restriction endonuclease analysis, and rDNA typing. The analysis of 11 enzyme loci resulted in 122 distinct enzyme types among 153 strains. Restriction endonuclease and rDNA patterns were different for each of 58 strains tested. Identical rDNA patterns (but not restriction endonuclease patterns) were found for some strains with the same enzyme type. Of the 96 strains available for phage-typing, 78 (81 %) were susceptible to at least one of the 25 phages tested and belonged to 73 distinct phage types. Although phage typing may provide useful phenotypic information if used in conjunction with at least one other typing method, it is specific to the genus Aeromonas and requires materials that are not commercially available. The other methods are universally applicable in bacteriology and may, therefore, be of greater importance to public health laboratories.