Penicillin-binding proteins in Bacteroides fragilis.

Abstract
The penicillin-binding proteins (PBS) of B. fragilis, a clinically important gram-negative rod, were studied. Four PBP were detected by polyacrylamide gel electrophoresis/fluorography, PBP 4 (MW, 35,000) being a minor PBP. The PBP pattern was thus different from that of the Enterobacteria and pseudomonads. Antibacterial activity of .beta.-lactam antibiotics was associated with binding to PBP 1 (MW, 100,000), 2 (MW, 86,000) and 3 MW, 68,000). Binding to PBP 2 was associated with filamentation; binding to PBP 1 resulted in cell lysis.