Antigenic properties and susceptibility to antibiotics of strains of Staphylococcus aureus in the 94, 96 phage complex.

Out of the 2,527 strains typed in 1976, 1977, 1978 and 1979, 226 strains (8.94%) were lysed by phages 94, 96 or 94 + 96. The two phages lyse together 83.17% of strains, whilst phage 94 alone lyses only 3.96% and phage 96 alone 12.87%. 94/96 strains have the S. aureus species antigens, particularly that of biotype A (human) at levels similar to those previously described: Protein A 96%, beta Ribitol teichoic acid (93%). Very characteristic is the presence in these strains of type antigens c1 (89%) and sigma (92%), which are significantly unusual or absent in the strains of other phages types. 94-96 complex strains are sensitive to antibiotics except resistance to Penicillin G (95%), Tetracycline (48%), Doxycycline (25%). Relation between lysis by phages 94-96 and presence of antigens c1 and sigma is discussed.