comparative study of beta-lactamase activity in the hl1 strain and in the conjugated strains allows confirmation of the transfer of an r-factor from the hl1 strain : in all these strains , the beta-lactamase has the same pi ( 5.3 ) and the same vmax ( relative to benzylpenicillin ) for ampicillin , carbenicillin and cephaloridin .
C0030827
benzylpenicillin
C0002680
ampicillin