Effect of some substances on the Actinomycetes sensitivity to antibiotics

ABSTRACT The effect of EDTA and CuSo4 on sensitivity of two species of Actinomycetes group including Rhodococcus and Kocuria to antibiotics (Ciprofloxacin and Gentamicin) was studied and the results showed that Rhodococcus was inhibited very well by Ciprofloxacin with inhibition zone 34 mm and Kocuria was inhibited by Gentamicin with inhibition zone 38 mm. Minimum inhibitory concentration for these antibiotics was determined the results revealed that the MIC for ciprofloxacin against Rhodococcus was 0.3 g /ml and for Gentamicin against Kocuria was 1.2 g/ml. The effects of EDTA and CuSo4 on the MIC of the two antibiotics appear to decrease them to 0.1 g/ml.