In a prospective multicenter study, 367 fecal samples from 300 patients with diarrhea were tested for Clostridium difficile-associated diarrhea (CDAD) with a new immunochromatography assay for toxins A and B (ICTAB), a real-time PCR on the toxin B gene, and the cell cytotoxicity assay. Twenty-three (6.2%) of the 367 fecal samples were positive by the cell cytotoxicity assay. With the cell cytotoxicity assay as the "gold standard," the sensitivity, specificity, positive predictive value, and negative predictive value for the ICTAB assay and real-time PCR were 91, 97, 70, and 99%, and 87, 96, 57 and 99%, respectively. In conclusion, both the ICTAB and the real-time PCR can be implemented as rapid screening methods for patients suspected of having CDAD.Clostridium difficile-associated diarrhea (CDAD) is the most important infectious cause of nosocomial diarrhea and pseudomembranous colitis. The enteropathogenicity depends on the production of enterotoxin A (308 kDa) and cytotoxin B (270 kDa). Several authors have suggested that all fecal samples for C. difficile from patients with diarrhea hospitalized for more than 72 h be investigated (3) irrespective of the physician's request, since length of hospitalization is simple to implement as an inclusion criterion. Conventional diagnostic methods for CDAD are the cell cytotoxicity assay and the enzyme immunoassays (EIA) to detect fecal toxins A (TcdA) and B (TcdB). The cell cytotoxicity assay is considered the "gold standard." However, with a turnaround time of more than 48 h, this method is laborious and time-consuming. Frequently, EIA are used because of their more rapid turnaround time. Rapid diagnosis of CDAD is important, since it may result in early treatment and prevention of nosocomial transmission.A new rapid immunochromatography test, the ImmunoCard Toxins A&B (ICTAB; Meridian), has recently been introduced. The ICTAB is a single-test enzyme immunoassay for the detection of TcdA and TcdB in fecal samples within 20 min. No sample pretreatment is required, and an internal procedure control is integrated in each card. The performance of this rapid assay was evaluated in comparison with an in-housedeveloped, real-time PCR using tcdB and the cell cytotoxicity assay. A positive PCR result for a fecal sample is indicative of the presence of a C. difficile strain capable of producing TcdB. Fecal samples from adult patients with diarrhea for whom there was a request for C. difficile diagnosis and samples from patients hospitalized for more than 72 h were included. All samples were stored within 6 hours after arrival at the laboratory at Ϫ20°C in two individual vials for subsequent testing by the cell cytotoxicity assay and real-time PCR at the LUMC. The ICTAB was performed in the Erasmus MC and the LUMC. All fecal samples were thawed only once for a specific test.The ICTAB was performed according to the respective manufacturer's instructions. Briefly, enzyme conjugate was added to specimen diluent before the addition of 25 l of the fecal sample or the control. After i...

Atypical mycobacterial skin infections are difficult to diagnose owing to their aspecific histopathologic presentations and to the presence of few bacteria. Therefore, these infections are often not recognized. Molecular detection of mycobacterial DNA has proven to be useful in clinical samples. The aim of this study was to investigate the incidence of mycobacterial involvement in skin biopsies showing granulomatous inflammation, using real-time polymerase chain reaction (PCR). Real-time PCR specific for the genus Mycobacterium and the species Mycobacterium avium and Mycobacterium haemophilum was performed on formalin-fixed/paraffin-embedded biopsies from patients with granulomatous inflammation of the skin, from the period 1984 to 2004. A control group was assembled from patients with proven basal cell carcinoma. Amplicons of all positive reactions were sequenced to confirm or identify the mycobacterial species. Of 30 patients, 13 (43%) were found to be positive for mycobacterial infection, of whom only 5 patients had been previously diagnosed with a mycobacterial disease. M. haemophilum was identified as the most common species (n=7). The other identified species were Mycobacterium malmoense, Mycobacterium gordonae, and Mycobacterium marinum. The results show that real-time PCR is useful in detecting mycobacterial infections in undiagnosed formalin-fixed/paraffin-embedded skin samples and that the application of molecular approaches would improve the diagnoses of mycobacterial skin infections.