Pseudomonas pseudomalleiisolates collected over 25 years from a non-tropical endemic focus show clonality on the basis of ribotyping

Abstract

SUMMARYBetween 1966 and 1991, melioidosis, a disease caused byPseudomonas pseudomalleithat is mostly confined to tropical regions, occurred in farm animals and a farmer in temperate south-west Western Australia. Using anEscherichia coliprobe containing a ribosomal RNA operon,P. pseudomalleiDNA from isolates from 8 animals, a soil sample and the human case showed an identical ribotype on Southern blotting. The ribotype was different from the 3 commonest ribotypes seen in tropical Australia. This molecular typing supports the theory of clonal introduction ofP. pseudomalleiinto a non-endemic region, with environmental contamination, local dissemination and persistence over 25 years. As melioidosis is often fatal in humans, such persistence in a temperate region is cause for concern.