[Characterization of bacteriophage nontypable patterns of S. aureus strains]

Out of 195 strains of S. aureus isolated from in and outpatients. 43 were proven not to be lysed by the chosen set of bacteriophages. Of these nontypeable strains 14 were isolated from blood cultures and septic wounds of patients from Poznań University Hospital. 29 strains were derived from the anterior nares or throat swabs of outpatients, who were treated for chronic pharyngitis in the children's clinic in Poznań. S. aureus was identified using standard bacteriological method. Sensitivity tests to antibiotics were performed using the ATB computer system (bioMérieux). Beta lactamase production was examined using the iodometric method. The intracellular esterases of S. aureus were separated by polyacrylamid gel electrophoresis and stained with Fast Blue using alpha-naphtyhl acetate, beta-naphthyl propionate and indoxyl acetate as substrates. A much higher percentage of S. aureus strains isolated from specimens obtained from the hospital patients showed the ability to produce beta-lactamase than the strains cultured from outpatients. The esterase patterns of S. aureus are helpful in differentiating bacteriophage nontypeable strains.