title: Suitability of stx-PCR directly from fecal samples in clinical diagnostics of STEC.
abstract: PCR-based testing for Shiga toxin producing Escherichia coli (STEC) directly from fecal samples is increasingly being implemented in routine diagnostic laboratories. These methods aim to detect clinically relevant amounts of microbes and not stx-carrying phages or low backgrounds of STEC. We present a diagnostic procedure and results from 1 year of stx-targeted real-time PCR of fecal samples from patients with gastrointestinal symptoms in Norway. A rapid stx2 subtyping strategy is described, which aims to quickly reveal the virulence potential of the microbe. stx was detected in 22 of 3320 samples, corresponding to a PCR positive rate of 0.66%. STEC were cultured from 72% of the PCR positive samples. Four stx1 isolates, eight stx2 isolates, and four isolates with both stx1 and stx2 were identified. With the method presented, stx-carrying phages are not commonly detected. Our results support the use of molecular testing combined with classical culture techniques for routine diagnostic purposes.
authors: Unit of Gene Technology, Department of Multidisciplinary Laboratory Medicine and Medical Biochemistry, Division of Diagnostics and Technology, Akershus University Hospital, Nordbyhagen, Norway.
authors: Hege S
authors: HS
authors: Tunsjø
authors: Unit of Gene Technology, Department of Multidisciplinary Laboratory Medicine and Medical Biochemistry, Division of Diagnostics and Technology, Akershus University Hospital, Nordbyhagen, Norway.
authors: Anne K
authors: AK
authors: Kvissel
authors: Unit of Gene Technology, Department of Multidisciplinary Laboratory Medicine and Medical Biochemistry, Division of Diagnostics and Technology, Akershus University Hospital, Nordbyhagen, Norway.
authors: Benoit
authors: B
authors: Follin-Arbelet
authors: Unit of Gene Technology, Department of Multidisciplinary Laboratory Medicine and Medical Biochemistry, Division of Diagnostics and Technology, Akershus University Hospital, Nordbyhagen, Norway.
authors: Beth-Marie
authors: BM
authors: Brotnov
authors: Department of Microbiology and Infection Control, Division of Diagnostics and Technology, Akershus University Hospital, Nordbyhagen, Norway.
authors: Trond E
authors: TE
authors: Ranheim
authors: Department of Microbiology and Infection Control, Division of Diagnostics and Technology, Akershus University Hospital, Nordbyhagen, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Truls M
authors: TM
authors: Leegaard
mesh_terms: D004927:Escherichia coli Infections / Q000175:diagnosis; D005243:Feces / Q000382:microbiology*; D005516:Food Microbiology; D006801:Humans; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction; D022622:Shiga Toxin 1 / Q000096:biosynthesis / Q000235:genetics*; D022641:Shiga Toxin 2 / Q000096:biosynthesis / Q000235:genetics*; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D022622:Shiga Toxin 1; D022641:Shiga Toxin 2
keywords: Enterohemorrhagic E. coli; Shiga toxin producing Escherichia coli; real-time PCR; screening; stx-carrying phages