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.
|Original language||English (US)|
|Number of pages||8|
|Journal||Diagnostic Microbiology and Infectious Disease|
|State||Published - Feb 2007|
Bibliographical noteFunding Information:
The authors are grateful to Stéphanie Gouriou, Catherine Branger, and Bertrand Picard for providing some of the strains used in this study and to Stéphane Bonacorsi and Edouard Bingen for discussions in the early conception of the assay. This work was supported in part by the “Fondation pour la Recherche Médicale” (E.D.) and Office of Research and Development, Medical Research Service, Department of Veterans Affairs, Minneapolis, MN (J.R.J.).
- Allele specific PCR
- Bloodstream isolates
- Escherichia coli
- Serotype O