Typing of clinical and environmental Aeromonas veronii strains based on the 16S-23S rDNA spacers

Genetic relationships of Aeromonas veronii strains isolated from human and environmental sources were investigated by restriction fragment length poly morphism (RFLP) of the polymerase chain reaction-amplified intergenic space r region (ISR) flanked by the 16S and 23S rRNA genes. When using endonuclea ses AluI, HinfI and CfoI the 16S-23S rDNA-RFLP patterns showed considerable overall similarity, although most strains yielded specific profiles. Sever al intra-specific lines of descent comprised clinical strains linked to iso lates from environmental sources. Strains having identical patterns may be individuals derived from highly similar, if not the same, microorganism. Re sults suggest that the ISR sequence-based method can be used to demonstrate colonization of a public water supply with a particular microorganism. In addition it could be very useful for tracing recurrent episodes of diarrhea and Aeromonas infection outbreaks. (C) 2000 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.