Eo. Mason et al., DISTRIBUTION OF STREPTOCOCCUS-PNEUMONIAE RESISTANT TO PENICILLIN IN THE USA AND IN-VITRO SUSCEPTIBILITY TO SELECTED ORAL ANTIBIOTICS, Journal of antimicrobial chemotherapy, 36(6), 1995, pp. 1043-1048
Surveillance by 33 laboratories in 19 states during a 4 1/2 month peri
od between December 1993 and April 1994 found that 263 of 1627 (16.2%)
isolates of Streptococcus pneumoniae were resistant to penicillin. On
e hundred and seventy (10.4%) isolates were determined to be intermedi
ately resistant to penicillin (MICs 0.1-1.0 mg/L and 93 (5.7%) were fo
und to be highly resistant to penicillin (MICs > 2.0 mg/L). MIC(90s) f
or intermediately penicillin resistant strains were: amoxycillin/clavu
lanate 2.0 mg/L, cefaclor 64 mg/L, cefixime 32 mg/L, cefprozil 8 mg/L
and loracarbef 128 mg/L. MIC(90s) for highly penicillin resistant stra
ins were: amoxycillin/clavulanate 4.0 mg/L, cefaclor greater than or e
qual to 128 mg/L cefixime 64 mg/L, cefprozil 32 mg/L and loracarbef gr
eater than or equal to 128 mg/L.