Biological characters and bacteriophage typing of Staphylococcus aureus isolated from chicken staphylococcosis and commercial balanced chicken food in Argentine.

During 1976-78, 33 S. aureus strains were isolated from chickens suffering from dermatitis and septicemia, omphalitis, pneumonia, arthritis and tenosynovitis; and from a commercial balanced chicken food. All the strains were classified into the biotype B of Hájek and Marsálek. Twenty-nine (87.8%) strains could be classified into Sato et al biological type 4 although they differed from it in its ability to grow at 45 degrees C. The remaining 4 strains differed from the others because they failed in producing hemolysis in bovine and ovine blood agar, egg yolk reaction and splitting of Tween 80. Thirty (90.9%) strains were lysed by avian phages: 28 strains at 1 x RTD and 2 at 100 x RTD. Twenty seven (93.1% strains of the Sato et al biotype 4 were sensitive to the phages CH42/CH43/CH63/CH37 of avian group II, and 2 strains to the phage CHA1 at 100 x RTD. Only one of the 4 unclassified strains could be typed by phage CH4 of avian group I at 1 x RTD. Twenty seven (81,8%) strains were typable at 100 x RTD by the basic set of human phages: 26 strains belonged to group III (53 and 53/77) and 1 to a mixed group I/III (79/53/77). The typable strains belonged only to Sato et al biotype 4. None of 33 strains were sensitive to any of the bovine phages. The biological characters and bacteriophage typing of the S. aureus showed that almost all the strains belong to chicken types. The strains isolated from food belong to the same chicken biotype and phagetype as the strains isolated from dermatitis, septicemia, omphalitis and pneumonia. The strains isolated from arthritis and tenosynovitis were different from the ones isolated from other pathologies.