Skurnik, Mikael4; Biedzka-Sarek, Marta4; Lubeck, Peter S.4; Blom, Tea4; Bengoechea, Jose Antonio4; Perez-Gutierrez, Camino4; Ahrens, Peter1; Hoorfar, Jeffrey3
1 National Veterinary Institute, Technical University of Denmark2 Division of Microbiology and Risk Assessment, National Food Institute, Technical University of Denmark3 National Food Institute, Technical University of Denmark4 unknown
Yersinia enterocolitica serotype O:9 is a gram-negative enteropathogen that infects animals and humans. The role of lipopolysaccharide (LPS) in Y. enterocolitica O:9 pathogenesis, however, remains unclear. The O:9 LPS consists of lipid A to which is linked the inner core oligosaccharide, serving as an attachment site for both the outer core (OC) hexasaccharide and the O-polysaccharide (OPS; a homopolymer of N-formylperosamine). In this work, we cloned the OPS gene cluster of O:9 and identified 12 genes organized into four operons upstream of the gnd gene. Ten genes were predicted to encode glycosyltransferases, the ATP-binding cassette polysaccharide translocators, or enzymes required for the biosynthesis of GDP-N-formylperosamine. The two remaining genes within the OPS gene cluster, galF and galU, were not ascribed a clear function in OPS biosynthesis; however, the latter gene appeared to be essential for O:9. The biological functions of O:9 OPS and OC were studied using isogenic mutants lacking one or both of these LPS parts. We showed that OPS and OC confer resistance to human complement and polymyxin B; the OPS effect on polymyxin B resistance could be observed only in the absence of OC.
Journal of Bacteriology, 2007, Vol 189, Issue 20, p. 7244-7253