The clinical impact of implementing GenMark ePlex blood culture panels for around-the-clock blood culture identification; a prospective observational study.

Background: Implementing rapid molecular blood culture diagnostics in the clinical management of sepsis is essential for early pathogen identification and resistance gene testing. The GenMark ePlex blood culture panels offer a broad microbial spectrum with minimal hands-on time and approximately 1.5 h to result. Therefore, ePlex can be utilized at times when the clinical microbiology laboratory is unavailable.Methods: From 23 October 2019 to 30 December 2019, consecutive non-duplicate positive blood cultures signalling microbial growth at the 24 h/7 days-a-week available clinical chemistry laboratory between 9 pm and 7 am were analysed with ePlex. All blood cultures were transported to the microbiology laboratory the following day for conventional identification and antibiotic susceptibility testing.Results: We used ePlex to test 91 blood cultures, of which 86 had confirmed microbial growth. Eighty-one were positive for ePlex target pathogens. The ePlex results were in complete agreement with conventional methods in 72/81 (88.9%) of cases and available within a median of 10.9 h earlier. Resistance gene targets (11 mecA and 1 CTX-M) were concordant with phenotypic susceptibility in all cases. In 18/86 (20.9%) of the patient cases, there was an opportunity to optimize antimicrobial therapy based on the ePlex result. The ePlex result affected clinical decision-making in 4/86 (4.7%) of the cases and reduced the average time to effective antimicrobial therapy by 8.9 h.Conclusions: Our implementation of ePlex is a feasible option to attain around-the-clock blood culture identification in many hospitals. It can significantly reduce time-to-pathogen identification and have an impact on clinical decision-making.

Toxin production by and adhesive properties of Clostridium difficile isolated from humans and horses with antibiotic-associated diarrhea.

Clostridium difficile is a common nosocomial pathogen in humans and animals that causes diarrhea and colitis following antibiotic therapy. Isolates of C. difficile obtained from faecal material from 20 human patients and 6 equine subjects with antibiotic-associated diarrhea were investigated regarding production of toxins A and B, their capacity to adhere to the human intestinal Caco-2 cell line and equine intestinal cells, and for the presence of fimbriae. The results showed that most (17/20) of the human clinical isolates produced both toxins A and B. One of the human isolates proved toxin A-negative/toxin B-positive. All (6/6) horse isolates were positive for both toxins A and B. Both the human and horse isolates possessed the capacity to adhere, to varying degree, to human and equine intestinal cells. It appeared that human isolates produced greater amounts of toxin B, and that there was a host-species dependency on ability to attach to intestinal epithelial cells. No fimbriae were found in any of the investigated isolates.