Isolation and characterization of tetracycline resistance proteins from Staphylococcus aureus and Escherichia coli.

Immunoglobulin (adsorbed resistance antiserum) reacting specifically with antigens from tetracycline (Tc)-resistant Staphylcoccus aureus or Escherichia coli was produced by adsorbing immunoglobulin against cell envelopes of resistant strains with envelope extracts from the respective isogenic susceptible strains. Adsorbed resistance antiserum against S. aureus reacted with envelope extracts from 32 Tc-resistant strains and failed to react with similar extracts from 76 Tc-susceptible strains of S. aureus. An antigen (Tc resistance antigen [TRA]) found only in Tc-resistant strains was produced by adsorbing envelope extracts from these strains with immunoglobulin against envelopes from isogenic Tc-susceptible strains. On immunodiffusion no cross-reactivity between TRAs from S. aureus and E. coli was observed. The TRAs behaved as proteins. The molecular weight of TRA from S. aureus was determined to be 32,000 and from E. coli to be 50,000. Data obtained by preliminary amino acid analysis of the TRAs are presented.