Value of rRNA gene restriction patterns of Aeromonas spp. for epidemiological investigations

We have investigated the value of rRNA gene restriction (rDNA) patterns for strain discrimination aeromonads isolated from clinical and environmental sources. Chromosomal DNA was purified and digested with restriction enzymes Pst I and Sma I, and the resulting fragments were separated by agarose gel electrophoresis and stained with ethidium bromide. The DNA was transferred to membranes (Southern blotting), where it was probed with biotinylated plasmid pKK3535 DNA. Hybridization bands were developed with the BluGene (BRL) kit. The resulting rDNA patterns were visually analyzed for similarities between epidemiologically related strains. Serotyping results for typable strains were consistent with strain designations derived by analysis of rDNA patterns. The specificity, reproducibility, stability, and ease of performance, especially with the nonisotopic probe, make ribotyping a valuable method for epidemiological investigations of Aeromonas infections.