Hardy Diagnostics now offers a convenient way of testing ß-lactamase activity in bacteria. The rapid Nitrocef test consists of a disk that is impregnated with the Nitrocefin reagent, which is a chromogenic cephalosporin. This rapid test can yield clinically relevant information earlier than an MIC test. A positive ß-lactamase test can predict resistance to such antibiotics as penicillin, ampicillin, amoxicillin, and other ß-lactamase containing drugs for the following organisms:
- Neisseria gonorrhoeae
- Haemophilus spp.
- Moraxella (Branhamella) catarrhalis
- Staphylococcus spp.
- Enterococcus spp.
- Anaerobes (such as some species of Bacteroides, Porphyromonas, Clostridium, Fusobacterium, Prevotella)
The rapid Nitrocef Disk test can be used for all of the above organisms with results in 5 minutes or less, with the exception of some Staphylococcus spp. that may take up to one hour. The ß-lactamase test is preferred to disk diffusion and agar dilution for the detection of plasmid-mediated beta-lactamase resistance in gonococci. These HardyDisks™ are packages loose in a glass vial.