Partial characterization of a genomic island associated with the multidrugresistance region of Salmonella enterica Typhymurium DT104

This study describes the identification of the insertion site and partial c haracterization of a 43-kb region harboring the genes associated with the p enta-resistant phenotype of a Canadian isolate of Salmonella enterica Typhy murium DT104 labelled 96-5227. The 43-kb fragment, here referred to as Salm onella genomic island I (SgiI), was found in the genome of S. enterica Typh ymurium between the thdf and a prophage CP-4-like integrase (int2) gene and is flanked by an imperfect 18-bp direct repeat. A region downstream of sun in the right end of SgiI contained four open reading frames which includes an IS6100 element, and a 2-kb region from the left end contained two open reading frames which showed homology to an integrase and an excisionase. Fu rthermore, a 1.9-kb retron sequence located between int2 and yidY was ident ified which may be unique to the S. enterica Typhymurium genome. The int-re tron sequence is flanked by a 27-bp imperfect direct repeat. (C) 2000 Feder ation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.