[Increased resistance of streptococcus pneumoniae to antibiotics and prevalence of their capsular serotypes (author's transl)].

From January 1970 to December 1976, 867 strains of Streptococcus pneumoniae isolated from clinical specimens were routinely typed and tested for sensitivity to 12 antibiotics. The prevalent serotypes were 19, 23, 6, 3, 7 and 14. Twenty seven p. cent of the strains were found resistant to tetracycline, and 4,2% were resistant to tetracycline and chloramphenicol. Two strains were resistant to erythromycin. The minimal inhibitory concentrations of penicillin G, cephalotin, chloramphenicol, tetracycline, minocycline and erythromycin were determined by the agar dilution method on 80 strains. The incidence of tetracycline resistant strains increased from 10% to 40%. These strains were less susceptible to minocycline when tested in vitro and they were clinically resistant. Chloramphenicol resistant strains are isolated since 1972 and represented in 1976 more than 6% of the isolates. They belong to 14 different serotypes. We have previously reported that resistance to chloramphenicol is due to a chloramphenicol-acetyl-transferase which is probably plasmid mediated. The epidemiological and clinical implications of these results are discussed.