[Antibiotic sensitivity of plasmonegative and plasmopositive staphylococci isolated from patients in 1970-1977]

The dynamics of sensitivity to benzylpenicillin, streptomycin, levomycetin, tetracycline, erythromycin and monomycin of 2529 plasmopositive and 1336 plasmonegative staphylococci isolated in 1970--1977 from patients with various purulent inflammatory diseases was analyzed. The objects of the study were pus from closed foci (abscesses, phlegmons, furuncles), wound contents, sputum, urine, blood, bile and abdominal exudate. The plating was usually performed with a purpose of diagnosis within the first hours of the patient admission to the hospital or during the treatment course. The antibiotic sensitivity of the microbes was determined with the method of standard paper discs. During the period of observation it was found that the percentage of strains sensitive to benzylpenicillin was always higher in plasmonegative staphylococci (P less than 0.001). This value ranged within 30.7--45.0 per cent in plasmopositive cultures and 41.2--70.4 per cent in plasmonegative cultures. The frequency of streptomycin sensitive cultures among plasmopositive and plasmonegative staphylococci was the same, i.e. within 34.6--59.5 per cent. The specific weight of the strains sensitive to levomycetin decreased from 50.6 to 26.6 per cent in plasmopositive cultures and from 60.0 to 27.0 per cent in plasmonegative cultures. The respective figures for erythromycin were from 77.6 to 46.7 and from 68.2 to 37.6 per cent.