Utilizzo del sistema Uro-Quick per l’identificazione rapida di batteri produttori di ß-lattamasi a spettro esteso (ESBL)

Objectives: To evaluate the Uro-Quick system for detection of extended-spectrum beta-lactamase (ESBL) among nosocomial strains isolated from urine during a 2 months period. Methods:A total of 221 strains collected from nosocomial patients were tested for antibiotic susceptibility by the Uro-Quick system. About 106 cell/ml were used to seed 2.5 ml of broth in vials containing ceftazidime (10 μg/mL) and ceftazidime (10 μg/mL) plus clavulanic acid (10 μg/mL). After incubation the results were plotted as growth curves. All results were confirmed by Kirby-Bauer method. Control strains were included. Results: Using an inoculum of 106 cell/ml the instrument was capable to print out the result after 5 hours of incubation.Among the pathogens studied, 46 strains resulted resistant to ceftazidime (presence of growth).These results were then compared with those obtained with the Kirby-Bauer method, and it was found that among these 46 ceftazidime-resistant clones all were ESBL-producers, even if 12 showed an intermediate, and 12 a susceptible antibiotic phenotype by Kirby-Bauer method. Conclusion: Present findings suggest that Uro-Quick represents a useful technology to detect ESBL-producing strains especially those that required further confirmatory tests for their identification.The period of time needed to achieve the results, in some cases less than 5 hours, might be an advantage over the usual methodologies.