title: Development of PCR assays targeting genes in O-antigen gene clusters for detection and identification of Escherichia coli O45 and O55 serogroups.
abstract: The Escherichia coli O45 O-antigen gene cluster of strain O45:H2 96-3285 was sequenced, and conventional (singleplex), multiplex, and real-time PCR assays were designed to amplify regions in the wzx (O-antigen flippase) and wzy (O-antigen polymerase) genes. In addition, PCR assays targeting the E. coli O55 wzx and wzy genes were designed based on previously published sequences. PCR assays targeting E. coli O45 showed 100% specificity for this serogroup, whereas by PCR assays specific for E. coli O55, 97/102 strains serotyped as E. coli O55 were positive for wzx and 98/102 for wzy. Multiplex PCR assays targeting the E. coli O45 and the E. coli O55 wzx and wzy genes were used to detect the organisms in fecal samples spiked at levels of 10(6) and 10(8) CFU/0.2 g feces. Thus, the PCR assays can be used to detect and identify E. coli serogroups O45 and O55.
authors.affiliation: Gastroenteric Disease Center, The Pennsylvania State University, Wiley Lab, Wiley Lane, University Park, PA 16802, USA. rcd3@psu.edu
authors.forename: Chitrita
authors.initials: C
authors.lastname: DebRoy
authors.forename: Pina M
authors.initials: PM
authors.lastname: Fratamico
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Roberts
authors.forename: Michael A
authors.initials: MA
authors.lastname: Davis
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D019081:O Antigens / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D012703:Serotyping
chemical_list: D029968:Escherichia coli Proteins; D019081:O Antigens