The Journal of Medical Microbiology, Vol 8, Issue 1 39-46, Copyright © 1975 by Society for General Microbiology
Variation in the properties of a strain of Staphylococcus aureus isolated over three months from a single hospital
R. W. Lacey, E. Lewis and J. Harrison
A strain of Staphylococcus aureus has been isolated from a hospital
environment over 3 months. Every isolate was lysed by phage 77, had
high-level resistance to streptomycin, and was resistant to about 250 pg
per ml of both tetracycline and sulphonamide; a combination of
sulphamethoxazole and trimethoprim produced little bacteristatic synergy
towards each isolate. All These organisms were thus considered to be "the
same"; the variation in other properties was probably due to rapid
evolutionary change in vivo. the variation in senxitivity to methicillin
and neomycin, and the absence of penicillinase production in some isolates,
probably indicated loss of the relevant genes. Several isolates had
probably acquired resistance to lincomycin by a one-step mutatuon in vivo.
The usefulness of lincomycin and analogues in treating staphylococcal
infections seems limited.
