On-site verification of the CBEU method using UriSelect4 chromogenic medium at the National Institute of Hygiene (INH) of Lomé.

Abstract

The Cytobacteriological Examination of Urine (CBEU) is one of the most requested microbiological analyses in the medical bacteriology laboratory. According to the ISO 15189 standard, Medical Biology Laboratory (MBL) must validate the techniques before their use. It is in this perspective that, within the Medical Bacteriology Laboratory of the INH of Lome, we have carried out the on-site verification of the CBEU method using UriSelect4 chromogenic medium at the INH of Lomé. The biological material was composed of reference bacterial strains and clinical bacterial strains isolated at INH. Failure Modes Effects and Criticality Analysis (FMECA) with 5​M model was used to perform risk analysis and performances as repeatability, intermediate fidelity/reproducibility, sensitivity and inter-operator variability were evaluated using references strains and different operators. "Comité Français d'Accréditation" (COFRAC) SH GTA 04 was used as reference. Single-factor ANOVA was used to analyze the data. Operating procedures, Patients preparation, Samples and Preparation of culture media were identified as main critical points with a criticality index of 8, 9, 9 and 12 respectively. The use of uriselect4 to perform ECBU was shown to be repeatable and reproducible. The sensibility of Uriselect4 to detect urinary infection was 100% with negligible inter-operator variability. This study performed on-site verification of Uriselect4 at the bacteriology lab of INH of Lome and identified some critical points to master. The overall performance criteria from COFRAC SH GTA 04 were conform.