[Resistance of Streptococcus pneumoniae to penicillin. "Bacteriological" resistance/"clinical" resistance]

From January 1988 to December 1992, 143 Streptococcus pneumoniae strains have been isolated at a significant level from 136 patients hospitalized in the pulmonary care unit of CHI Créteil. The clinical presentations were: 83 pneumonia (P), 48 acute bronchitis (B) and 12 colonizations (C). Fourteen strains were found to be penicillin resistant (MIC > 0.125 mg. l-1): 11 P, 2 B, 1 C. Two patients were lost of view after the beginning of the treatment: a pneumonia (Serotype 23F, MIC = 2 mg. l-1) and a bronchitis (Serotype 23F, MIC = 2 mg. l-1). Treatment was pristinamycine for one and amoxicilline alone or associated to clavulanic acid for the other 13. We observed the failure of the treatment in two. A pneumonia (Serotype 23, MIC = 2 mg. l-1) was treated before hospitalization by josamycine (3 days), then cefpodoxime (4 days) and amoxicillin-clavulanic acid (1.5 gr/d during 7 days). Healing was obtained with the increase to 3 gr/d. The other failure was a pneumonia without improvement after 11 days with 3 gr/d of amoxicilline. The treatment was stopped during 5 days and a protected brushing was performed. A Streptococcus Pneumoniae (Serotype 23F, MIC = 8 mg. l-1) was isolated. The clinical status rapidly improved with erythromycine (3 gr/d) to which the strain was susceptible. "Bacteriological" Resistance to penicillin is demonstrated (10 percent in our sample, 17 percent in France during 1991). However amoxicillin to a sufficient dosage is still enough ("Clinical" Resistance < 1 percent in our sample) for the treatment of respiratory infections except when the MIC is at a high level.