DISTRIBUTION OF INSERTION-SEQUENCE IS200 AMONG DIFFERENT CLONAL LINESOF THE RELATED SALMONELLA SEROTYPES LIVINGSTONE AND EIMSBUETTEL

The copy number and genetic location of IS200 have provided evidence o f strain relatedness in many serotypes of Salmonella. In this study, 1 00 isolates of the related serotypes Livingstone (6,7:d:l,w) and Eimsb uettel (6,7,<(14)under bar>:d:l,w), representing 10 ribotype/biotype ( RT/BT) groups isolated from human and non-human sources in seven count ries over a 26-year period, were examined for their IS200 profiles. Th e distribution of IS200 in strains of these serotypes was limited, bei ng present in all 53 isolates of ribotype 1 (RT1) and its variant type RT6, in one of five isolates of RT5 but in none of 42 isolates of RTs 2, 3 or 4, Although the seven IS200 profiles identified in RT1 isolat es were of little value for further discrimination within different bi otype groups, they were extremely valuable for confirming serotype: is olates of RT1/BT8/IS200 profile A (or its variants) and those of RT1/B T3/IS200 profile B (or its variants) were almost invariably associated with serotypes Livingstone and Eimsbuettel, respectively.