Insertion Element IS 3 -Based PCR Method for Subtyping Escherichia coli O157:H7

• Published in: Journal of clinical microbiology Vol. 36; no. 5; pp. 1180 - 1184
• Main Authors: Thompson, Curt J., Daly, Claire, Barrett, Timothy J., Getchell, Jane P., Gilchrist, Mary J. R., Loeffelholz, Mike J.
• Format: Journal Article
• Language: English
• Published: 01.05.1998
• ISSN: 0095-1137; 1098-660X
• DOI: 10.1128/JCM.36.5.1180-1184.1998

ABSTRACT An Escherichia coli O157:H7 subtyping method based on PCR amplification of variable DNA sequences between the repetitive element IS 3 was developed. Template DNA was prepared by boiling cells in Chelex. Two separate IS 3 PCR amplifications were performed for each isolate: one with a single primer (primer IS3A) and one with two primers (primers IS3A and IS3B). The IS 3 PCR subtyping method was applied to 35 epidemiologically related and unrelated E. coli O157:H7 isolates that had been previously characterized by pulsed-field gel electrophoresis (PFGE). PFGE identified 25 different subtypes (difference of one or more bands). PCR with single primer IS3A and primer pair IS3A-IS3B identified 6 and 14 different subtypes, respectively. By combining the results of the two PCR amplifications, 15 different IS 3 PCR subtypes were identified. While not as sensitive as PFGE, IS 3 PCR subtyping grouped all outbreak-related isolates. IS 3 PCR banding patterns were reproducible between amplifications and between subcultures. IS 3 PCR could serve as a simple, rapid screening method for the identification of unrelated E. coli O157:H7 isolates.