Characterization of the Chromosomally Mediated Penicillinase in Klebsiella pneumoniae

The gene governing ampicillin resistance and penicillinase production in Klebsiella pneumoniae was analyzed by means of a conjugation system. The gene, amp , was mapped between pyr4 and aro18 on the linkage map of K. pneumoniae . The chromosomally mediated penicillinases of k. pneumoniae were partially purified and their properties were compared with those of known species‐specific penicillinases of K. pneumoniae and also those of the penicillinases of R factors having ampicillin resistant marker. The chromosomal penicillinases were consistent with most of the species‐specific penicillinases in enzymological and immunological properties and in their behavior on agar gel electrophoresis. They also showed a close relationship to type I penicillinases of R factors in enzymological and immunological properties.