gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples

The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA) is a chitin-binding protein involved in V . cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V . cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V . cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR) samples. Overall, the method is sensitive (50 gene copies), highly specific for V . cholerae and failed to amplify strains of the closely-related species Vibrio mimicus . The sensitivity of the assay applied to environmental and stool samples spiked with V . cholerae ATCC 39315 was comparable to that of pure cultures and was of 10 2 genomic units/l for drinking and seawater samples, 10 1 genomic units/g for sediment and 10 2 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V . cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V . cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME) is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies

Raccomandazioni per l’identificazione e la gestione dei risultati critici nei laboratori clinici

Critical results (also known as panic or alarm results) identify a laboratory test result associated with a serious risk for the patient's health, requiring immediate communication to the physician to establish appropriate therapeutic interventions. The adoption of an efficient procedure for the communication of critical values/results is crucial for clinical, ethical, organizational reasons, because it is a requirement for laboratory accreditiation and because of potential legal consequences related to the lack of notification of harmful laboratory results. In 2008, the Italian Society of Clinical Biochemistry and Laboratory Medicine (SIBioC) published its first consensus-based recommendation for the detection and management of critical values in clinical laboratories, with the aim to improve the implementation of standardized and universally accepted procedures, promoting an essential policy toward rational and efficient solutions to this issue. These new recommendations represent a complete review of the first document. Using the same consensus conference method between experts of scientific societies, the main aspects of clinical risk, patient safety and legal liability of health care workers were re-considered. The SIBioC and the Italian Society of Laboratory Medicine (SIPMeL), Intersociety Study Group on Standardization of extra-analytical variability of laboratory results, together with the Italian Society of Ergonomics and Human Factors (SIE) collaboration, issued the present join document