Epidemiologic typing of Escherichia coli using RAPD analysis, ribotyping and serotyping

AbstractObjectiveTo compare random amplified polymorphic DNA (RAPD) analysis and ribotyping with serotyping for epidemiologic typing of Escherichia coli.MethodsThirty-two epidemiologically unrelated strains, nine cerebrospinal fluid isolates with the O7K1 serotype from nine patients, and nine sets of epidemiologically related E. coli isolates from nine patients were typed by RAPD analysis, ribotyping and serotyping.ResultsAmong the 32 epidemiologically unrelated E. coli isolates, 29 types were distinguished by RAPD analysis, 25 by ribotyping and 27 by serotyping. Indistinguishable patterns were obtained by RAPD analysis and ribotyping within the collection of nine cerebrospinal fluid isolates. For the epidemiologically related isolates, intrapatient variation was only found by RAPD analysis among the isolates of one set and by ribotyping among the isolates of two sets. No interpatient variation was observed between three sets of isolates. With serotyping, the epidemiologically related isolates yielded similar typing relationships to those obtained by RAPD analysis and ribotyping.ConclusionsRAPD analysis had the highest discriminatory capacity for typing E. coli isolates. RAPD analysis, ribotyping and serotyping can all be used for assessment of strain relationships

Development and implementation of a vehicle-pedestrian conflict analysis method: Adaptation of a vehicle-vehicle technique

This paper examines the development, use, and evaluation of a new traffic conflict analysis technique that specifically addresses pedestrian-vehicle conflicts with the intention of being applicable to shared-space environments. The method is based on an existing, well-established, and widely used vehicle-vehicle conflict analysis technique, but is adapted to consider the movement of pedestrians, which differs significantly from that of vehicles. The new method is then implemented on the Exhibition Road site of West London with the use of video data collected from locations with a potentially high concentration of vehicle-pedestrian conflicts, and the results of the analysis are presented. Finally, the results are compared with those obtained by other conflict analysis techniques and also against accident data to assess not only the accuracy but also the functionality of the new technique

Analysis of pedestrian-vehicle traffic conflicts in street designs with elements of shared space

This paper investigates changes in pedestrian-vehicle traffic conflicts in urban streets redesigned according to the principles of shared space, using a recently developed Pedestrian-Vehicle Conflicts Analysis (PVCA) method. In a first step, the PVCA method is revised to more accurately reflect the features of shared space: this includes the definition of a systematic process for identifying conflict occurrences on one hand, and the full quantification of the conflict severity grading process on the other. Then, the refined PVCA method is applied to a case study in London, using video data from periods before and after the redevelopment of the Exhibition Road site from a conventional dual carriageway to a modern design with some elements of shared space. The results of the comparative analysis carried out indicate a general decrease in traffic conflict rates as a result of the redesign, but also highlight specific issues that may require additional analysis

Survival of massive allografts in segmental oncological bone defect reconstructions

Reconstructions of large segmental bone defects after resection of bone tumours with massive structural allografts have a high number of reported complications including fracture, infection and non-union. Our goal is to report the survival and complications of massive allografts in our patients. A total of 32 patients were evaluated for fracture, infection, non-union rate and survival of their massive allograft reconstructions. The average follow-up for this group was five years and three months. The total fracture rate was 13% with a total infection rate of 16%. We found a low union rate of 25%. The total survival of the allografts was 80.8% (± 18.7%) after five years. We found a five-year allograft survival of 80.8% which is comparable with other studies