AMB Volume 40, Issue 2, 2024 Pages 199-204 https://doi.org/10.59393/amb24400207
Evaluation of HB&L Uroquattro System for Rapid Antimicrobial Susceptibility Testing Directly From Positive Urine Samples
Snegarova-Toneva V., Niyazi D.S., Stoeva T.
The aim of the study was to evaluate the concordance of the rapid antimicrobial susceptibility testing (AST) results obtained by the HB&L Uroquattro instrument performed directly from positive urine samples in comparison with the standard Kirby-Bauer disk- diffusion method performed with isolated colonies. We included 122 urine samples defined as positive by the HB&L system screening method. The AST was performed directly from them by the HB&L instrument. Simultaneously, all positive urine samples were cultured on CLED, MacConkey and Blood agar and incubated for 24h at 37°C. Species identification and AST of the pathogens isolated on solid media were done by the VITEK 2 automated system (bioMerieux) and respectively by the Kirby-Bauer disk-diffusion method. We defined one hundred and twenty-two positive urine samples:60 Enterobacterales, 42 Enterococcus faecalis, and 20 Staphylococcus saprophyticus isolates. A total of 690 susceptibility determinations were performed with a categorical agreement with the standard method of 94.8%. Thirty-six errors (5.2%) were found. Of these, only 5 very major errors were detected, associated with trimethoprime/sulfamethoxazole susceptibility testing among Enterobacterales, glycopeptides, and HLAR among enterococci and cefoxitin susceptibility among staphylococci. The turnaround time for AST directly from positive urine samples was between 3 and 5 hours versus 48 hours for the standard disk-diffusion method from isolated colonies.
The rapidity of the HB&L AST method and its very good categorical correlation with the standard disk-diffusion method determine the potential of the system for wide application in routine laboratory practice.
Keywords: urinary infections, HB&L, rapid antimicrobial susceptibility testing
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