[Evaluation of a new and rapid antibiotic sensitivity method testing for Enterobacteriaceae responsible for urinary infections].

URIFAST Es et Es Plus (International Microbio, Signes, France) are rapid antimicrobial susceptibility testing method in broth medium without using an automatic reader. A screening assay (URIFAST Quatro 1C ou URIFAST Twin 1C) is performed with a 4 or 9 antimicrobial agents with a concentration c' below the low critical concentration (c) defined by the Comité de l'Antibiogramme de la Société Française de Microbiologie (CA-SFM). When a bacterial strain is presumed resistant, an antimicrobial susceptibility test with the two critical concentrations (CA-SFM) can be performed with 5 or 10 antimicrobial agents antibiotiques (URIFAST Twin ABG ou URIFAST ABG). 140 strains of Enterobacteriaceae from urinary tract infections; E. coli (n = 94), P. mirabilis (n = 13), K. pneumoniae (n = 4), K. oxytoca (n = 6), C. diversus (n = 3), P. vulgaris (n = 1), M. morganii (n = 3), C. freundii (n = 4), E. aerogenes (n = 2), E. cloacae (n = 5) and S. marcescens (n = 5); were isolated with CPS ID2 (bioMérieux, Marcy l'Etoile, France). URIFAST results were compared to Rapid ATB Ur et ATB Ur results obtained after reading with ATB expression (bioMerieux). For each discrepancy, the minimal inhibitory concentration (MIC) by agar dilution was used as the reference method. Agreement obtained were 98.57% with Quatro 1C, 98.40% with Twin 1C, 98.14% with Twin ABG and 98.39% with ABG. 94% of beta-lactams susceptible Enterobacteriaceae were detected by the screening tray with the antimicrobial agent concentration c'. URIFAST Es et Es Plus are standardized and easy-to-use methods. Because of their good performances, the URIFAST methods can be used to test antimicrobial susceptibility for Enterobacteriaceae from urinary tract infections.