Characterisation of Clostridium difficile Hospital Ward–Based Transmission Using Extensive Epidemiological Data and Molecular Typing

A population-based study in Oxfordshire (UK) hospitals by Sarah Walker and colleagues finds that in an endemic setting with good infection control, ward-based contact cannot account for most new cases of Clostridium difficile infection

Modified Multiple-Locus Variable-Number Tandem-Repeat Analysis for Rapid Identification and Typing of Clostridium difficile during Institutional Outbreaks▿

A modified multiple-locus variable-number tandem-repeat analysis (MMLVA) method was validated on Clostridium difficile-infected stool specimens from institutional outbreaks. The method allows simultaneous detection of toxin genes, deletions, and tandem repeats from cultured isolates or stool specimens. Results were used to aid institutional outbreak investigation by identifying clusters of NAP1/027

Detection of Severe Acute Respiratory Syndrome Coronavirus in Stool Specimens by Commercially Available Real-Time Reverse Transcriptase PCR Assays

Three commercially available real-time reverse transcriptase PCR assays (the Artus RealArt HPA coronavirus LightCycler, the Artus RealArt HPA coronavirus Rotor-Gene, and the EraGen severe acute respiratory syndrome coronavirus POL assay) and three RNA extraction methodologies were evaluated for the detection of severe acute respiratory syndrome coronavirus RNA from 91 stool specimens. The assays' sensitivities were highest (58% to 75%) for specimens obtained 8 to 21 days after symptom onset. The assays were less sensitive when specimens were obtained less than 8 days or more than 21 days after the onset of symptoms. All assays were 100% specific

Multicenter Comparison of Nucleic Acid Extraction Methods for Detection of Severe Acute Respiratory Syndrome Coronavirus RNA in Stool Specimens

The emergence of a novel coronavirus (CoV) as the cause of severe acute respiratory syndrome (SARS) catalyzed the development of rapid diagnostic tests. Stool samples have been shown to be appropriate for diagnostic testing for SARS CoV, although it has been recognized to be a heterogeneous and difficult sample that contains amplification inhibitors. Limited information on the efficiency of extraction methods for the purification and concentration of SARS CoV RNA from stool samples is available. Our study objectives were to determine the optimal extraction method for SARS CoV RNA detection and to examine the effect of increased specimen volume for the detection of SARS CoV RNA in stool specimens. We conducted a multicenter evaluation of four automated and four manual extraction methods using dilutions of viral lysate in replicate mock stool samples, followed by quantitation of SARS CoV RNA using real-time reverse transcriptase PCR. The sensitivities of the manual methods ranged from 50% to 100%, with the Cortex Biochem Magazorb method, a magnetic bead isolation method, allowing detection of all 12 positive samples. The sensitivities of the automated methods ranged from 75% to 100%. The bioMérieux NucliSens automated extractor and miniMag extraction methods each had a sensitivity of 100%. Examination of the copy numbers detected and the generation of 10-fold dilutions of the extracted material indicated that a number of extraction methods retained inhibitory substances that prevented optimal amplification. Increasing the volume of sample input did improve detection. This information could be useful for the extraction of other RNA viruses from stool samples and demonstrates the need to evaluate extraction methods for different specimen types

Outbreak of acupuncture-associated cutaneous Mycobacterium abscessus infections

BACKGROUND: Cutaneous atypical mycobacterial infections have been increasingly described in association with cosmetic and alternative procedures. OBJECTIVE: We report an outbreak of acupuncture-associated mycobacteriosis. Between April and December 2002, 32 patients developed cutaneous mycobacteriosis after visiting an acupuncture practice in Toronto, Canada. RESULTS: Of 23 patients whose lesions were biopsied, 6 (26.1%) had culture-confirmed infection with Mycobacterium abscessus. These isolates were genetically indistinguishable by amplified fragment length polymorphism. The median incubation period was 1 month. Of 24 patients for whom clinical information was available, 23 (95.8%) had resolution of their infection. All patients developed residual scarring or hyperpigmentation. CONCLUSION: Nontuberculous mycobacteria should be recognized as an emerging, but preventable, cause of acupuncture-associated infections