Organization of Escherichia coli O157 O Antigen Gene Cluster and Identification of Its Specific Genes
AUTOR(ES)
Wang, Lei
FONTE
American Society for Microbiology
RESUMO
The O157:H7 clone of Escherichia coli, which causes major, often prolonged outbreaks of gastroenteritis with hemolytic-uremic syndrome (HUS) such as those in Japan, Scotland, and the United States recently, is thought to be resident normally in cattle or other domestic animals. This clone is of major significance for public health and the food industry. We have developed a fast method for sequencing a given O antigen gene cluster and applied it to O157. The O157 O antigen gene cluster is 14 kb in length, comprising 12 genes and a remnant H-repeat unit. Based on sequence similarity, we have identified all the necessary O antigen genes, including five sugar biosynthetic pathway genes, four transferase genes, the O unit flippase gene, and the O antigen polymerase gene. By PCR testing against all 166 E. coli O serogroups and a range of gram-negative bacterial strains, including some that cross-react serologically with E. coli O157 antisera, we have found that certain O antigen genes are highly specific to O157 E. coli. This work provides the basis for a sensitive test for rapid detection of O157 E. coli. This is important both for decisions on patient care, since early treatment may reduce the risk of life-threatening complications, and for detection of sources of contamination. The method for fast sequencing of O antigen gene clusters plus an ability to predict which genes will be O antigen specific will enable PCR tests to be developed as needed for other clones of E. coli or, once flanking genes are identified, clones of any gram-negative bacterium.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=108385Documentos Relacionados
- Sequencing of Escherichia coli O111 O-Antigen Gene Cluster and Identification of O111-Specific Genes
- Development of Primers to O-Antigen Biosynthesis Genes for Specific Detection of Escherichia coli O157 by PCR
- Biocontrol of Escherichia coli O157 with O157-Specific Bacteriophages
- Identification of a Rough Strain of Escherichia coli O157:H7 That Produces No Detectable O157 Antigen
- A PCR Specific for Escherichia coli O157 Based on the rfb Locus Encoding O157 Lipopolysaccharide