to investigate a cause of the high ampicillin resistance , the beta-lactamase-producing plasmid , ptms1 , was transferred by conjugation to a penicillin-susceptible gonococcal strain as well as to its isogenic multiply antibiotic-resistant transformants , and the susceptibility of the transconjugants to ampicillin was determined .
C0018081
gonococcal
C0002680
ampicillin