it is only in some streptococcus pneumoniae , methicillin-resistant staphylococcus aureus and streptococcus faecalis strains that altered penicillin-binding proteins make a significant contribution to the resistance to beta-lactams . beta-lactamases will continue to be the most important factor in clinically significant resistance of bacteria to both penicillins and cephalosporins .
C0597979
beta
C0004611
bacteria