Evaluation of the Thermo Scientific RapidFinder™ Salmonella Species, Typhimurium, and Enteritidis Multiplex PCR Kit.

The Thermo Scientific RapidFinder™ Salmonella Species, Typhimurium, and Enteritidis Multiplex PCR Kit (candidate method) is a real-time PCR assay for the detection and differentiation of Salmonella spp., and the serovars S. Typhimurium, and S. Enteritidis from poultry, pork, and environmental samples. The method was validated in comparison to the U.S. Department of Agriculture Food Safety and Inspection Service and the U.S. Food and Drug Administration reference methods. Thermo Fisher Scientific (Basingstoke, United Kingdom) tested all matrixes. In addition, two matrixes were analyzed independently by Q Laboratories, Inc. (Cincinnati, OH). Few statistically significant differences were found between the candidate and reference methods when analyzed by probability of detection. When differences were observed, these were in favor of the candidate method. All 200 inclusivity strains and none of the 45 exclusivity strains were detected, which demonstrated that the RapidFinder Salmonella Species, Typhimurium, and Enteritidis Multiplex PCR Kit was able to detect all the major groups of Salmonella, the less common subspecies of S. enterica, and the rarely encountered S. bongori. None of the exclusivity isolates analyzed were detected. Robustness testing demonstrated that the assay gave reliable performance, with specific method deviations outside the recommended parameters. Accelerated stability testing was conducted, validating the assay shelf life.

Laboratory evaluation of Brilliance™ CRE Agar for screening carbapenem-resistant Enterobacteriaceae: Performance on a collection of characterised clinical isolates from Greece.

The performance of Oxoid Brilliance™ CRE Agar (BCRE), a new chromogenic medium designed for screening of carbapenem-resistant Enterobacteriaceae, was evaluated on a collection of clinical isolates of enterobacteria (n=175) and non-fermenters (n=55) with known ß-lactam resistance mechanisms and levels of susceptibility to carbapenems. BCRE supported the growth of 100 of 108 enterobacterial isolates that were non-susceptible to at least one carbapenem, whilst excluding 57 of the 67 carbapenem-susceptible isolates. The eight non-susceptible isolates that did not grow on BCRE were carbapenemase-producers with low carbapenem minimum inhibitory concentrations, mostly exhibiting non-susceptibility only to one carbapenem. In total, of 107 carbapenemase-producing enterobacteria that were included in the study, 16 did not grow, with most of them being either susceptible (n=8) or intermediate-susceptible (n=5) to carbapenems. Regarding the 10 carbapenem-susceptible enterobacteria that were not excluded by BCRE, 1 produced a carbapenemase and the rest possessed strong backgrounds of various other ß-lactam resistance mechanisms. The medium allowed growth of almost all carbapenem-resistant non-fermenting isolates; nevertheless, non-fermenters were clearly differentiated from Enterobacteriaceae by colony colour and morphology.