Evidence that Tn5565, which includes the enterotoxin gene in Clostridium perfringens, can have a circular form which may be a transposition intermediate

The Clostridium perfringens enterotoxin gene is on a transposon-like elemen t, Tn5565, integrated in the chromosome in human food poisoning strains. Th e flanking IS elements, IS1470 A and B, are related to IS30. The IS element found in the transposon, IS1469, is related to IS200 and has been found up stream of cpe in all Type A strains. PCR and sequencing studies From cell e xtracts and plasmid isolations of C. perfringens indicate that Tn5565 can f orm a circular form with the tandem repeat (IS1470)(2), similar to the tran sposition intermediates described for a number of IS elements. (C) 1999 Fed eration of European Microbiological Societies. Published by Elsevier Scienc e B.V. All rights reserved.