Observations on multiple-antibiotic-resistant epidemic strains of Staphylococcus aureus

SOME PHYSIOLOGICAL CHARACTERISTICS OF NEOMYCIN AND KANAMYCIN-RESISTANT STRAINS OF STAPHYLOCOCCUS AUREUS

Five hundred and fifty-two strains of Staphylococcus aureus of hospital origin were resistant to penicillin, streptomycin, and tetracycline. Of these, 298 were also resistant to neomycin and kanamycin, and this resistance was related to pigment production on glycerol monoacetate agar, the production of beta-lysin, the absence of fibrinolytic and proteolytic activity, and to phage susceptibility. The use of physiological markers, the inadequacy of phage typing, and the possible reasons for the emergence of neomycin-resistant staphylococci are discussed.

THE EVOLUTION OF NEW HOSPITAL STRAINS OF STAPHYLOCOCCUS AUREUS

The emergence of new groups of strains of Staph. aureus as important causes of endemic hospital infection in Great Britain has been followed by the phage typing method. Experiments are reported which suggest the possible origin of one of them.

Cultural characters of a newly recognized group of hospital staphylococci

Members of a newly recognized group of hospital staphylococci, which are believed to have arisen from 83A staphylococci by lysogenization, differ from them in several cultural characters. Some but not all of these characters appear to be determined by the carriage of phage.