Niaz Banaei (previously Banaiee)

Publication Details

  • A Sensitive Multiplex, Real-Time PCR Assay for Prospective Detection of Shiga Toxin-Producing Escherichia coli from Stool Samples Reveals Similar Incidences but Variable Severities of Non-O157 and O157 Infections in Northern California. Journal of clinical microbiology Lefterova, M. I., Slater, K. A., Budvytiene, I., Dadone, P. A., Banaei, N. 2013; 51 (9): 3000-3005


    Rapid and accurate detection of Shiga-toxin producing E. coli of all serotypes from patients with diarrhea is critical for medical management and for prevention of ongoing transmissions. In this prospective study, we assessed the performance of a multiplex, real-time PCR assay targeting stx1 and stx2 for detection of O157 and non-O157 Shiga-toxin producing E. coli from diarrheal stool samples enriched in GN broth. We show that the assay is 100% sensitive (95% confidence interval (CI), 89.1% to 100%) and 98.5% specific (95% CI, 90.6% to 99.9%), based on a panel of 40 known STEC-positive and 65 known negative specimens. During a two-year post-validation period, the assay detected a greater number of positive samples from patients in Northern California compared to culture and PCR testing performed at a public health reference laboratory, with a positive predictive value of 95.6% (95% CI, 87.6% to 99.1%). Serotyping data showed an incidence rate of 51.2% for non-O157 STEC strains with 5.8% (1/17) of patients with non-O157 strains and 42.9% (6/14) with O157 strains (P=0.03) developing hemolytic uremic syndrome. The findings from this study underscore the recommendations of the CDC for laboratories to test all diarrheal stool samples from patients with acute community-acquired diarrhea for non-O157 STEC in addition to O157 serotype using a sensitive assay. Additionally, a survey of 17 clinical laboratories in Northern California demonstrated that nearly 50% do not screen all stool specimens for the presence of Shiga toxins, indicating that many clinical microbiology laboratories still do not routinely screen all stool specimens for the presence of Shiga toxins recommended in the 2009 CDC guidelines.

    View details for DOI 10.1128/JCM.00991-13

    View details for PubMedID 23843484

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