Impiego del sistema URO-QUICK per l’esecuzione rapida di antibiogrammi direttamente su campioni di urine

Abstract

During the period june-october 2003 the urine samples were examined employing routine methods for strain identification and the Kirby-Bauer technique for antibiotic susceptibility tests.This usual system was compared with the new rapid Uro-Quick method employed on samples resulting positive and mono-microbial after Gram coloration. Antibiotic (in appropriate concentration) was introduced in a vial containing 2 ml of Mueller-Hinton broth, then 0.5 ml of urine were added in each vial containing the antimicrobial molecules and even in a vial without drug used as control.After 3-5 hours of incubation (for Gram negative or Gram positive strains respectively) the instrument shows the results. No growth and a growth curve like the control are representative of a susceptible and resistant strain respectively). Gram negative strain were tested against ciprofloxacin, nitrofurantoin, co-clavulanate, ceftazidime, fosfomycin, imipenem, amikacin, and trimethoprim-sulfamethoxazole, while Gram positive bacteria against ciprofloxacin, nitrofurantoin, co-clavulanate, ampicillin, fosfomycin, gentamycin, oxacillin and trimethoprim-sulfamethoxazole.The Gram negative strains isolated were 1172 and the Gram positive were 261.With the first group agreement between the two methods was always more than 90%, against Gram positive pathogens there was more than 80% of agreement. In conclusion against the mayor urinary tract pathogens (E. coli, Enterococci, Klebsiella spp. and Proteus spp.) agreement between the Uro-Quick system and the Kirby- Bauer was more than 90%.The rapid method appears useful not only for the determination of the antibiotic susceptibility of common uropathogens, but, on the basis of the present findings, it could be suggested the use of this rapid method in more severe nosocomial infections.