Diagnostic device > Diagnostic discs
DIAGNOSTIC DISCS 100 discs Code: DD 515
for the differentiation of coagulase negative Staphylococci
Purpose and usage:
NOVOBIOCIN diagnostic discs are designed for an easy differentiation of plasmacoagulase negative Staphylococci.
The test is based on the resistance of some species of plasmacoagulase negative Staphylococci to novobiocin.
Inoculate evenly Mueller-Hinton agar plate with the examined strain (it is better to prepare a flood plate by inoculating 3 hr. broth culture with a turbidity of 0.5 according to McFarland scale). Put NOVOBIOCIN disc by aseptic technique on the plate and incubate for 24 hours at 37°C.
Measure the diameter of the inhibition zone after incubation:
Inhibition zone (mm) Staphylococci to novobiocin
< 15 Resistant
> 15 Susceptible
Resistant species of coagulase negative staphylococci:
Human medicine: Staphylococcus xylosus, S. saprophyticus, S. cohnii subs. cohnii, S. cohnii subs. urealyticum and rarely occuring species S. sciuri and S. lentus.
Veterinary medicine: S. gallinarum, S. arlettae, S. equorum and S. kloosii.
Other species of coagulase negative staphylococci described till now are susceptible to novobiocin.,
1. NOVOBICIN discs are designed for laboratory use only.
2. Discs should be stored in a dark place at +4°C and should not be used beyond the expiration date shown on the packing.