Validation of Three Rapid Screening Methods for Detection of Verotoxin-Producing Escherichia coli in Foods: Interlaboratory Study

An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced [ground] beef, unpasteurized milk, unpasteurized apple juice [cider], and salami) were individually inoculated with low numbers (<9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR

Invasive adenocarcinoma of the vagina following surgery for adenocarcinoma in situ of the cervix--recurrence or implantation?

A 51-year-old woman underwent cervical conization for severe glandular abnormal cells. Histology noted adenocarcinoma in situ (AIS) with incomplete excision margins. Four months later, hysterectomy revealed no residual disease. Six months subsequently she developed invasive adenocarcinoma of the upper vagina. This report documents the unusual behavior of AIS and its management difficulties.