Rapid and effective methods for the isolation of Clostridium difficile from stool samples are desirable to obtain isolates for typing or to facilitate accurate diagnosis of C. difficile-associated diarrhea. We report on the evaluation of a prototype chromogenic medium (ID C. difficile prototype [IDCd]) for isolation of C. difficile. The chromogenic medium was compared using (i) 368 untreated stool samples that were also inoculated onto CLO medium, (ii) 339 stool samples that were subjected to alcohol shock and also inoculated onto five distinct selective agars, and (iii) standardized suspensions of 10 C. difficile ribotypes (untreated and alcohol treated) that were also inoculated onto five distinct selective agars. Two hundred thirty-six isolates of C. difficile were recovered from 368 untreated stool samples, and all but 1 of these strains (99.6%) were recovered on IDCd within 24 h, whereas 74.6% of isolates were recovered on CLO medium after 48 h. Of 339 alcohol-treated stool samples cultured onto IDCd and five other selective agars, C. difficile was recovered from 218 samples using a combination of all media. The use of IDCd allowed recovery of 96.3% of isolates within 24 h, whereas 51 to 83% of isolates were recovered within 24 h using the five other media. Finally, when they were challenged with pure cultures, all 10 ribotypes of C. difficile generated higher colony counts on IDCd irrespective of alcohol pretreatment or duration of incubation. We conclude that IDCd is an effective medium for isolation of C. difficile from stool samples within 24 h.

To date, this is one of the largest documented outbreaks of E coli O157:H7 infection associated with unchlorinated recreational water and represents the first outbreak in which the strain was isolated from lake water. Guidelines are needed to decrease the risk of enteric illness associated with swimming in recreational lakes.

A total of 592 people reported gastrointestinal illness following attendance at Street Spice, a food festival held in Newcastle-upon-Tyne, North East England in February/March 2013. Epidemiological, microbiological and environmental investigations were undertaken to identify the source and prevent further cases. Several epidemiological analyses were conducted; a cohort study; a follow-up survey of cases and capture re-capture to estimate the true burden of cases. Indistinguishable isolates of Salmonella Agona phage type 40 were identified in cases and on fresh curry leaves used in one of the accompaniments served at the event. Molecular testing indicated entero-aggregative Escherichia coli and Shigella also contributed to the burden of illness. Analytical studies found strong associations between illness and eating food from a particular stall and with food items including coconut chutney which contained fresh curry leaves. Further investigation of the food supply chain and food preparation techniques identified a lack of clear instruction on the use of fresh uncooked curry leaves in finished dishes and uncertainty about their status as a ready-to-eat product. We describe the investigation of one of the largest outbreaks of food poisoning in England, involving several gastrointestinal pathogens including a strain of Salmonella Agona not previously seen in the UK.

Chromogenic media (CM) are available for urine specimens (US) to enable rapid identification of common urinary tract pathogens (UTP). Two CM, chromID™ CPS (CPS4) agar (bioMérieux, St. Laurent, QC) and UriSelect™ 4 (URS4) agar (Bio-Rad, Montreal, QC), were compared to the standard media (SM) for the isolation and identification of UTP. Over a 10-day period, US were inoculated to CPS4, URS4, and SM (BAP and MAC). CM interpretation was done according to the product inserts by one person blinded to the results of SM. SM were read by experienced technologists according to protocol and isolates were identified using BD Phoenix™. The results were grouped into significant (SG), mixed (MG), and no significant growth (NSG). A total of 903 US were studied. SM identified 239 SG, 112 MG, and 552 NSG cultures. The most common pathogens were Escherichia coli (38 %) and Enterococcus spp. (11 %). Comparing CM to SM, the exact agreement was 89.3 and 89.5 % for URS4 and CPS4, respectively. When grouped by clinical significance, agreement with SM was 93.0 and 93.1 % for URS4 and CPS4, respectively. CM were equivalent with respect to processing time. Advantages include decreased need for automated identification of certain species, particularly E. coli. In terms of workflow, CM enables same-day identification for almost 50 % of significant UTP. Overall, both CM compared well to SM and allowed for rapid preliminary identification of many UTP.