title: R factor-mediated increments in levels of resistance to and enzymatic degradation of penicillins and cephalosporins.
mesh_terms: D002511:Cephalosporins / Q000378:metabolism*; D004755:Enterobacteriaceae / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology*; D010403:Penicillin Resistance; D010406:Penicillins / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D010406:Penicillins