Evaluation of different buffered peptone water (BPW) based enrichment broths for detection of Gram-negative foodborne pathogens from various food matrices.

This study evaluated the effects of changing the composition of the pre-enrichment medium buffered peptone water (BPW) on the growth of stressed and unstressed Gram-negative foodborne pathogens in a one-broth enrichment strategy. BPW supplemented with an available iron source and sodium pyruvate, along with low levels of 8-hydroxyquinoline and sodium deoxycholate (BPW-S) improved the recovery of desiccated Cronobacter spp. from powdered infant formula. Growth of Salmonella and STEC was comparable in all BPW variants tested for different food matrices. In products with high levels of Gram-negative background flora (e.g. sprouts), the target organisms could not be reliably detected by PCR in any of the BPW variants tested unless the initial level exceeded 10(3) cfu/10 g of sprouts. Based on these results we suggest BPW-S for a one-broth enrichment strategy of stressed Gram-negative foodborne pathogens from dry products. However, a one-broth enrichment strategy based on BPW variants tested in this evaluation is not recommended for produce with a high level of Gram-negative background flora due to very high detection limits.

Preliminary evaluation of a virtual reality-based simulator for learning spinal anesthesia.

STUDY OBJECTIVE: To evaluate the influence of a simulation-based program on the initial performance of dural puncture by medical interns, and to refine the design of simulator-based teaching and competence assessment. DESIGN: Prospective interventional study. SETTING: Academic medical center. SUBJECTS: 27 medical interns inexperienced in the technique of spinal anesthesia or dural puncture and within 12 months of graduating from medical school, were randomly assigned to a conventional or a simulator-based teaching course of spinal anesthesia: 13 were recruited to the Conventional Group (CG) and 14 to the Simulator Group (SG). MEASUREMENTS: A SenseGraphic Immersive workbench and a modified Phantom desktop with shutter glasses were used to create a teaching environment. Outcomes of teaching were assessed in two phases within three weeks of the teaching course: Phase I consisted of a written examination followed by assessment on the simulator. A global rating scale and a task-specific checklist were used. Phase II (for those participants for whom a suitable opportunity arose to perform spinal anesthesia under supervision within three wks of the teaching course) consisted of structured observation of clinical performance of the procedure in the operating room. Participants were assessed by independent, study-blinded experts. Student's two-tailed impaired t-tests were used to compare the parametric outcomes (P < 0.05 was considered significant). MAIN RESULTS: All participants completed the written test successfully with no difference between groups. Ten participants from CG and 13 from SG completed the simulator-based testing performing similarly in terms of the global rating scale. Five participants in CG and 6 in SG proceeded to clinical testing. On the global rating scale, interns in SG scored higher than those in CG. They performed similarly according to the task-specific checklist. CONCLUSIONS: Overall, no difference was measured between those taught with traditional methods and those, by a simulator based program in regard to the performance of spinal anesthesia.

Molecular epidemiology of Campylobacter isolates from poultry production units in southern Ireland.

This study aimed to identify the sources and routes of transmission of Campylobacter in intensively reared poultry farms in the Republic of Ireland. Breeder flocks and their corresponding broilers housed in three growing facilities were screened for the presence of Campylobacter species from November 2006 through September 2007. All breeder flocks tested positive for Campylobacter species (with C. jejuni and C. coli being identified). Similarly, all broiler flocks also tested positive for Campylobacter by the end of the rearing period. Faecal and environmental samples were analyzed at regular intervals throughout the rearing period of each broiler flock. Campylobacter was not detected in the disinfected house, or in one-day old broiler chicks. Campylobacter jejuni was isolated from environmental samples including air, water puddles, adjacent broiler flocks and soil. A representative subset of isolates from each farm was selected for further characterization using flaA-SVR sub-typing and multi-locus sequence typing (MLST) to determine if same-species isolates from different sources were indistinguishable or not. Results obtained suggest that no evidence of vertical transmission existed and that adequate cleaning/disinfection of broiler houses contributed to the prevention of carryover and cross-contamination. Nonetheless, the environment appears to be a potential source of Campylobacter. The population structure of Campylobacter isolates from broiler farms in Southern Ireland was diverse and weakly clonal.