title: Determination of Escherichia coli O types by allele-specific polymerase chain reaction: application to the O types involved in human septicemia.
abstract: Escherichia coli can be serotyped by determination of somatic (O), capsular (K), and flagellar (H) antigens, and clear associations exist between specific O antigens and pathogenic behavior. However, E. coli is very challenging to O type with traditional serologic methods, making new methods for E. coli somatic antigen detection highly desirable. Here, we describe a simple alternative molecular method for determination of the E. coli O type based on allele-specific polymerase chain reaction amplification of the 5' portion of the rfb locus. We present our application of this new method to the detection of the 12 principal O types (O1, O2, O4, O6, O7, O12, O15, O16, O18, O25, O75, and O157) found among bloodstream isolates of E. coli. This method allowed us to determine the O types of 153 strains previously typed using reference methods with an accuracy exceeding 90%. Moreover, some rough or nonagglutinating strains can be successfully typed.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM) U722 and Faculté de Médecine Xavier Bichat, Université Paris 7 Denis Diderot, 75018 Paris, France. clermont@bichat.inserm.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Clermont
authors.forename: James R
authors.initials: JR
authors.lastname: Johnson
authors.forename: Megan
authors.initials: M
authors.lastname: Menard
authors.forename: Erick
authors.initials: E
authors.lastname: Denamur
mesh_terms: D000483:Alleles; D016470:Bacteremia / Q000175:diagnosis / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics; D017931:DNA Primers; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000382:microbiology; D006801:Humans; D005810:Multigene Family; D019081:O Antigens / Q000145:classification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D019081:O Antigens; C079397:rfb protein, Bacteria