Two hundred and thirty five stains of Streptcoxci which were isoletal fron various area of Taiwan Prouince. Stieptccoctus agaiactiae was deterrninats-J firstly by means of CAMP test and biological methods
Twenty antibiotic sensitive Streptcoxcus agalacthe with stble chaaacter were then selnl by means of antibiotic sensitivity test. The a&vementioned stains were ssagal in Trypucase hoth in which containing either Penicillin c’r Steptonycin. TheMICv,as cherDked every five ssages by means of Tu}e Dilution Method.
The result indicatal that resistance to ponicillin or streptonycin could ke induced in the hoth containing the antibiotics, Resistance was induced slowly in renicillin and the induced resistance only in altut 10 fold (range 2-50). The resistance to streptonycin was induced rapidly. hi first five passages, Steptoxtus agalactiae increased its resistancetostreptomycin by five foldin everage (range 1-25). then upto50fold (range 10-150). Changes in biological charxacter and noi-phorIogy had also keen oberved in induced antibiotic stains.