Lateral flow immunochromatographic assay for rapid screening of faecal carriage of carbapenemase-producing Enterobacteriaceae.

Background: Rapid and effective screening of carbapenemase-producing Enterobacteriaceae (CPE) appears essential for adequate patient management and rapid implementation of infection control measures. Most of these screening techniques require a minimum of 24 h of culture. Molecular assays are an exception since these can be achieved within 1 h, but are expensive and usually require specialized facilities and trained personnel. In this context, lateral immunochromatography performed directly from rectal swab samples could represent a cost-effective alternative with a reduced turnaround time. Objectives: In this study, we assessed the performance of the OKN K-SeT test (Coris BioConcept, Gembloux, Belgium) for the rapid detection of OXA-48, KPC and NDM CPE directly from rectal swab samples. Methods: A total of 149 residual rectal swabs, routinely screened for CPE through selective culture and confirmed by PCR, were tested with a defined protocol consisting of a 2.5 h incubation of the swab in an enrichment medium containing meropenem followed by OKN K-SeT testing after centrifugation. Results: This method displayed an overall sensitivity of 96% and a specificity of 100% with a limit of detection ranging between 104 and 105 cfu/mL. Conclusions: Whereas this assay appears highly specific, it displays a reduced sensitivity compared with the standard procedure encompassing a culture step. Nonetheless, this rapid method allows an accelerated identification of most CPE carriers at a lower cost and, accordingly, the implementation of early appropriate management procedures.

FGF23: Clinical usefulness and analytical evolution.

Fibroblast Growth Factor 23 (FGF23) is a key hormone for the regulation of phosphate homeostasis. Over the past decades, FGF23 was the subject of intense research in the fields of nephrology and the cardiology. It presents a remarkable correlation with well-established biomarkers of cardiovascular disorders in both chronic kidney disease (CKD) and heart failure (HF) patients. The interest of FGF23 lies in its early-onset in the primary course of CKD as well as in the incremental prognosis information it conveys in both CKD and HF. Different types of assays of FGF-23 testing exist, those targeting the intact form (iFGF23), the other one detecting terminal fragments (cFGF23). The issue is still pending which assay suits best for clinical use. Recently, the implementation of this biomarker on multianalyzer platforms, on which other markers of phospho-calcic balance are set up, allows a rapid turn-around-time and a potential financial gain. However, despite the good analytical performances of the automated methods, there is a poor harmonization between assays. The introduction of an international certified reference material should standardize the measurement and improve the harmonization of results from different laboratories. A deeper understanding of physio-pathological mechanisms and processing of FGF-23 should reinforce its clinical indications and might also identify new therapeutic targets for the treatment of CKD and HF.