title: A direct comparison of two unusual R-factor-mediated  -lactamases.
mesh_terms: D000667:Ampicillin; D002509:Cephaloridine; D003023:Cloxacillin; D004926:Escherichia coli; D005827:Genetics, Microbial; D008712:Methicillin; D010068:Oxacillin; D010400:Penicillin G; D010403:Penicillin Resistance; D010404:Penicillin V / Q000031:analogs & derivatives; D010405:Penicillinase
chemical_list: D000667:Ampicillin; D010405:Penicillinase; D002509:Cephaloridine; D003023:Cloxacillin; D010400:Penicillin G; D008712:Methicillin; D010068:Oxacillin; D010404:Penicillin V