[Variations of antimicrobical resistance of bacteria isolated in specimens of the respiratory tract (author's transl)].

Percentages of antimicrobical resistance of potentially pathogenic bacterial species with more frequent isolation, in the years 1973-1976, in specimens of the respiratory tract show some statistically significant variations. From the study of these variations of resistance in the years examined it follows that too near periods should not be compared as often has been noted from one year to the next a change of their direction. In a bacterial genus or in genera often considered akin for their antimicrobical susceptibility, differences that for some drugs resulted remarkable have been emphasised.