[Study of cefotaxime on stability to beta-lactamases and affinity to penicillin-binding proteins]

Cefotaxime (CTX) was compared with other cephems concerning stability to beta-lactamases and affinity to penicillin-binding proteins of Escherichia coli JE1011. The results are summarized as follows. 1. CTX showed potent activity against bacteria whose resistance is mediated by plasmids on chromosomal genes. 2. The antibacterial activity of CTX was not influenced by the transfer of 25 different plasmids to E. coli ML1410. 3. CTX was stable to typical cephalosporinases (CSases). This compound was slightly hydrolyzed by cefuroximases (CXases). 4. There was no difference between CTX and other cephems in the affinity to beta-lactamases. 5. CTX showed high affinity to the 1A, 1Bs and 3 fractions of penicillin-binding proteins of E. coli JE1011.