[Dynamics of drug resistance in Proteus mirabilis cultures 1970-1985].

Resistance of 669 clinical strains of Proteus mirabilis to 18 chemotherapeutic drugs was studied in dynamics within 1970-1985. An increase in the number of cultures resistant to ampicillin and carbenicillin was noted while the number of cultures resistant to cephalosporines did not change. Within the period from 1970 to 1975 there was observed a marked increase in the number of Proteus strains resistant to aminoglycoside antibiotics. After that period their number gradually lowered and in 1985 reached the level of 1970. Beginning from 1973 there were observed a decrease in the number of Proteus chloramphenicol resistant strains and simultaneous occurrence of cultures sensitive to this antibiotic. The predominating number of the tested strains preserved during the whole observation period their resistance to tetracycline, doxycycline, rifampicin, novobiocin, furazolidone and furagin. No increase in the number of Proteus strains with multiple drug resistance including those resistant to 5-7 drugs was noted in the observation periods of 1970-1975, 1980 and 1985. The most frequent were Proteus strains resistant to 2-4 drugs. Among them cultures resistant to chloramphenicol and aminoglycoside antibiotics of the first generation predominated. Grouping of the strains by the same resistance spectra provided dividing the rested cultures of Proteus mirabilis into 69 variants.