title: Development of PCR assays targeting the genes involved in synthesis and assembly of the new Escherichia coli O 174 and O 177 O antigens.
abstract: Escherichia coli O 174 and O 177 are newly described O serogroups which were reported as human pathogens. Identification of these strains by serotyping has been restricted, as the required sera are not commercially available. In this study, a collection of 13 E. coli O 174 strains and 12 E. coli O 177 strains was studied on the O:H serotypes and virulence markers. The O-antigen gene clusters of E. coli O 174 and O 177 were sequenced, and associated genes were assigned functions on the basis of homology. Two genes, each specific for E. coli O 174 and O 177, were identified. PCR assays based on the O-antigen-specific genes were developed and tested on 25 clinical and environmental isolates of those two serogroups as well as 26 isolates of other O serogroups. As little as 1 pg per mul of chromosomal DNA and as few as 0.1 CFU per g of pork and water samples were detected for either strain. The PCR assays established in this study were shown to be highly sensitive and reliable and could be the method of choice for detection of these two human pathogens from clinical, food, and other environmental samples.
authors.affiliation: Division of Microbial Toxins,Robert Koch Institut, Nordufer 20, D-13353 Berlin, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Beutin
authors.forename: Qingke
authors.initials: Q
authors.lastname: Kong
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
authors.forename: Quan
authors.initials: Q
authors.lastname: Wang
authors.forename: Gladys
authors.initials: G
authors.lastname: Krause
authors.forename: Luciana
authors.initials: L
authors.lastname: Leomil
authors.forename: Qi
authors.initials: Q
authors.lastname: Jin
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
mesh_terms: D000818:Animals; D002417:Cattle; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D019081:O Antigens / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013045:Species Specificity; D014774:Virulence
chemical_list: D029968:Escherichia coli Proteins; D019081:O Antigens