| a global gene pool for high-level cephalosporin resistance in commensal streptococcus species and streptococcus pneumoniae. | highly penicillin- and cephalosporin-resistant streptococcus mitis and streptococcus oralis were isolated in spain, hungary, and berlin. with chromosomal dna of these strains, resistant transformants of streptococcus pneumoniae were obtained that expressed low-affinity variants of penicillin-binding proteins (pbps) 2x, 1a, 2a, and 2b in different combinations, depending on the selective conditions. the transformants had cefotaxime mics of up to 6 microg/ml, and those with a low-affinity pbp 2b w ... | 1997 | 9333159 |