Patent ID: 7932051

Claim:
Method for the determination of the presence of an antibiotic in a fluid comprising the steps of: (a) contacting a sample of a fluid to be tested for the presence of an antibiotic with a test medium comprising an indicator and a test microorganism which is thermostable at an incubation temperature of between 50° C. and 70° C. and is selected from the group consisting of a Bacillus species and a Streptococcus species; (b) incubating the test microorganism at an incubation temperature of 60° C. to 65° C. for a period of time between 1.5 to 4 hours to grow the test microorganism in case no antibiotic is present in the fluid sample; and (c) detecting growth or inhibition of growth of the test microorganism with the indicator, wherein the method further comprises adding to the test medium and/or to the sample of the fluid an alkaline earth metal salt in an amount such that the concentration of the metal in the test medium and/or the sample is between 0.005 M and 1 M.