-Lactamases of subspecies of Bacteroides fragilis

Abstract

The β-lactamase activities of 64 strains of Bacteroides fragilis were studied. The subspecies of Bacteroides fragilis were found to have β-lactamases which focussed at distinctive isoelectric points. Five strains which showed a high degree of resistance to β-lactam antibiotics showed three separate types of resistance, two of which were enzymic. Cephalosporins showed variable degrees of susceptibility to hydrolysis by the Bacteroides fragilis enzymes but cefoxitin was unaffected.