URIFAST® ABG® V2

Intended use

Urinary tract infections are the second most important reason for consulting a family practice doctor after respiratory infections. In hospitals, urinary tract infections are the most frequent source of nosocomial infections and are difficult to treat and prevent. Most urinary tract infections are benign. However, infections may become pathological and result in complicated infections such as cystitis, chronic prostatitis, or even pyelonephritis.

Diagnosis of urinary tract infections relies upon the isolation of the germ responsible as well as the assessment of antibiotic susceptibility. For antibiotic susceptibility testing, the determination of the minimum inhibitory concentration (MIC) on agar is the reference method. However, this procedure is long and is not adapted to routine diagnosis nor to emergency situations. The URIFAST® ABG V2 kit has been designed to determine the susceptibility of Enterobacteriaceae to the most common antibiotics used in the treatment of bacterial urinary tract infections.

Principle
The determination of antimicrobial susceptibility is based upon the growth or the absence of growth of Enterobacteriaceae in the presence of 11 dehydrated antibiotic agents:

• 8 antibiotics tested at 2 concentrations (c and C) (amoxicillin, cephalothin, ceftriaxone, gentamicin, pipemidic acid, norfloxacin, ciprofloxacin, trimethoprim/sulphamethoxazole)
• 3 antibiotics tested at 1 concentration (amoxicillin/clavulanic acid, fosfomycin, nitrofurantoin)

The URIFAST® ABG V2 test uses a modified liquid Muëller-Hinton medium with a redox indicator (bromothymol blue).  In this method, the inoculum is standardized with the PRESTO ABG® inoculator. The URIFAST® ABG V2 test is easy to interpret with growth visualized by a color change of an indicator.  Results (MIC or breakpoints interpretation) are rapid and obtained within 4-5 hours of incubation.

The test is performed using colonies which should be young (up to 24 hours old) and perfectly isolated on an agar medium in a Petri dish.

The URIFAST® ABG V2 is:

• A rapid test with a handling time of 1 min and with results obtained within 4-5 hours.
• An easy-to-use test:
  • no suspension medium,
  • direct inoculation of the culture from only one isolated colony
• A convenient test with individual packaging, ready to use reagents, incubation at 35-37°C
• A simple and clear visual colorimetric method with no instrument required, no reading apparatus

All the necessary reagents are contained in the 20-well tray (1 test/tray) and no additional reagent is required to perform the test.

Simple protocol

Easy-to-read and easy-to-interpret results

The result is visualized by a simple spontaneous colorimetric reaction, without instrument or expert interpretation. Bacterial growth is indicated by a color change of the medium. Interpretation of the results and characterization of the strains as sensitive, intermediate or resistant to the antibiotics are described in the instruction leaflet.

It is a practical and easy-to-use laboratory test, giving accurate results from one isolated colonies within 4 to 5 hours.

Reagents and material

• URIFAST® Twin 1C V2 Trays:
  • Quantity: 25 trays
  • Each tray of 2×10 wells containing 9 antibiotics at different concentrations.
  • Each divisible tray allows the testing of two specimens.
• M4H:
  • Vial of modified Müeller-Hinton medium containing bromothymol blue.
  • Quantity: 50
• R4H:
  • Vial containing 5 mL of surfactant for use with Proteus mirabilis strains.
  • Quantity: 1

Stability and storage
The M4H medium and the trays are stable at 2 to 8 °C in their original packaging until the expiry date given on the kit.

The R4H reagent must be stored at room temperature as soon as the kit is received.

Should only one half of a URIFAST Twin 1C v2 tray be used, store the other half in its original packaging, resealed with the desiccant, at 2 to 8 °C. This is stable for 7 days.

Do not freeze the reagents in the kit.
Performance
A comparative study was carried out with the diffusion on agar reference method with overall concordance results of 97.3%.
Material required but not provided

• PRESTO ABG® inoculators (ELITech MICROBIO, Cat. N° 22204)
• Incubator at 35 – 37 °C
• Waste container for contaminated waste
• Pipettes and tips (100 μL)