Evaluation of Stuart's transport medium containing penicillinase. An in vitro study. Brief report

An in vitro study was performed to evaluate the value of penicillinase in Stuart's transport medium. Swabs were taken from serum broth cultures of Staphylococcus aureus, Escherichia coli and Proteus rettgeri, incubated with cefuroxime. Following 24 hours' storage in the transport medium, the recovery of P. rettgeri was significantly higher from Stuart's transport media containing penicillinase in a concentration of 100,000 units/ml, than from swabs stored in Stuart's medium without penicillinase. Although susceptible to cefuroxime, we did not find the same effect on S. aureus and E. coli, presumably because these strains had higher MIC values than the P. rettgeri strain tested.