among these strains of bacteria , 20 strains of s. aureus and 1 strain of s. pyogenes were also used , at the same inoculum size , for the determination of mics of 4 beta-lactam antibiotics including 3 different penicillins such as ampicillin ( abpc ) , methicillin ( dmppc ) and cloxacillin ( mcipc ) and cefaclor ( ccl ) , a cephem antibiotic .
C0030842
penicillins
C0025643
methicillin