DNA sequence of the insertional hot spot of Tn916 in the Clostridium difficile genome and discovery of a Tn916-like element in an environmental isolate integrated in the same hot spot

Tn916 is a broad host range tetracycline resistance conjugative transposon. In most bacteria, this element enters the bacterial genome at multiple sit es. However, in Clostridium difficile, the element has a strong hot spot wh en introduced by filter mating from Bacillus subtilis. In this work, the DN A sequence of the preferred insertion site (att916) was obtained. An enviro nmental isolate of C. difficile was also discovered which contained an elem ent indistinguishable from Tn916, Tn916CD. Tn916CD was found integrated at att916. (C) 2000 Federation of European Microbiological Societies. Publishe d by Elsevier Science B.V. All rights reserved.