Penicillin Resistance Correlated with Phage Types in Staphylococcus aureus

• Published in: Japanese Journal of Microbiology 1968-01, Vol.12 (1), p.1-6
• Main Authors: Fujisawa, Hiroyasu, Ishihara, Keizo
• Format: Article
• Language: English
• Subjects: Culture Media; Humans; Hydrogen-Ion Concentration; Mercury - pharmacology; Penicillin Resistance; Penicillins - pharmacology; Staphylococcus - drug effects; Staphylococcus - isolation & purification; Staphylococcus Phages - drug effects; Streptomycin - pharmacology; Tetracycline - pharmacology
• ISSN: 0021-5139; 1348-0421
• DOI: 10.1111/j.1348-0421.1968.tb00363.x

ABSTRACT The resistance of Staphylococcus aureus to penicillin G was studied quantitatively by the dilution method. A series of 338 strains obtained from patients fell into 3 groups according to degree of resistance; 150 highly resistant strains, 137 moderately resistant strains, and 51 sensitive strains. Furthermore, 287 strains resistant to 0.2 units per ml or more of penicillin fell into 2 groups according to antibiotic resistance pattern, 173 single resistant strains and 114 multiple resistant strains. The vast majority of the highly resistant strains belonged to phage‐groups I and III, whereas the majority of the moderately resistant strains belonged to group II. Of the highly resistant strains, 65% were multiple resistant, and 35% single resistant. Of the multiple resistant strains, 86% belonged to the 52, 52A, 80, 81 complex within group I and to group III, but none belonged to group II. Of the strains that were highly resistant to penicillin only, 83% belonged to group I, and of these, nearly one‐half were members of the 52, 52A, 80, 81 complex, and the other half belonged to the rest of phage‐types within group I. In contrast, 88% of the moderately resistant strains were single resistant, and of these, 58% belonged to group II. Mercury resistance was observed in 77% of the highly resistant strains of the multiple resistance pattern, 29% of those of the resistance to penicillin alone and 3% of the strains moderately resistant to penicillin alone. Of the mercury resistant strains, 68% belonged to the 52, 52A, 80, 81 complex, 3% to the rest of phage‐types in group I, 12% to group III, but none belonged to group II. The results suggest that there may exist a difference in the mechanisms of inactivating penicillin between strains of staphylococci highly resistant and moderately resistant to penicillin.