Previous Article | Next Article ![]()
Infection and Immunity, April 2002, p. 1832-1841, Vol. 70, No. 4
0019-9567/02/$04.00+0 DOI: 10.1128/IAI.70.4.1832-1841.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.
Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, 80336 Munich, Germany
Received 10 October 2001/ Returned for modification 20 November 2001/ Accepted 2 January 2002
The high-pathogenicity island (HPI) of yersiniae encodes an iron uptake system represented by its siderophore yersiniabactin (Ybt). The HPI is present in yersiniae with high levels of pathogenicityi.e., Yersinia pestis, Y. pseudotuberculosis, and Y. enterocolitica biogroup (BG) 1Bbut absent in Y. enterocolitica strains with low (BG 2 to 5) and no (BG 1A) levels of pathogenicity and has been shown to be an important virulence factor. Comparison of the HPI in Y. enterocolitica (Yen-HPI) and that in Y. pestis and Y. pseudotuberculosis revealed that, in contrast to genes of the variable region, genes of the core region (genes irp9 to fyuA) are highly homologous. In the present work the Yen-HPI core genes were rescued from the chromosome of Y. enterocolitica WA-C (BG 1B, serotype O:8) using the FRT-FLP recombinase system. Transfer of the resulting plasmid pCP1 into the siderophore-deficient strain Y. enterocolitica NF-O (BG 1A) led to no halo on siderophore indicator chrome azurol S (CAS) agar. Transfer of pCP1 into the Y. enterocolitica strain MRS40 (serotype O:9, BG 2; phenotype, CAS negative) led to a CAS halo larger than that of parental strain WA-C, indicating high Ybt production. pCP1 was highly unstable in iron-deficient medium, and no enhanced mouse virulence conferred by MRS40 carrying pCP1 could be detected. To overcome the problem of instability, pCP1 was integrated into the chromosome of MRS40, leading to the formation of a CAS halo comparable to that seen with WA-C and correspondingly to increased mouse virulence. Thus, the core genes of Yen-HPI are sufficient to confer a positive CAS phenotype and mouse virulence to Y. enterocolitica MRS40, BG 2, but are insufficient to confer this phenotype to Y. enterocolitica NF-O, BG 1A.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»