antibacterial activity via disk diffusion assay

[ken77]

Hi,

 

I have found a haze zone around antibiotic disk when testing via disk diffusion.

 

Would you class this antibiotic active or inactive?

 

Regards

[Micro.Pete]

Hi,

If you find a haze around your DD, and it appears to be bacteria (try to scrub it with a inoculation needle), it means the antibiotic isn't working against this microorganism.That applies only when you work with a clean isolate (when you have only 1 bacterial species). Because if you work with a mix culture, you can't be certain in 100% that the haze came from your tested bacteria or from other species in the mix culture.