EFFECT OF THE INOCULUM SIZE ON SUSCEPTIBILITY TESTS PERFORMED ON SESSILY GROWING BACTERIA

It has been clearly established that the inoculum size greatly affects the results of antibiotic susceptibility tests performed in both liqu id and solid media in standard laboratory growth conditions (i.e. Plan ktonic). Recently methods were developed to perform antibiotic suscept ibility tests on bacteria growing in sessile conditions. The present s tudy investigates the effect of the inoculum size on results obtained by these methods. Results show that the inoculum size does not affect tests performed in sessile conditions. A simple and reliable method is proposed to be applied to routine microbiological laboratory procedur es.