The relationship between drug susceptibility patterns and enzyme patterns in pathogenic gram-positive cocci

Abstract

Classification on the basis of carbon requirements, in the form of substrates in the Krebs tricarboxylic acid cycle, placed the pathogenic gram-positive cocci (Strep. pyogenes [Lancefield A], enterococcus and pneumococcus) in group 1, and Staph. aureus in group 2. Of one hundred eighty-nine clinical strains of staphylococci, 70.4 per cent were urease-positive and 29.6 per cent were urease-negative by cultural methods. Sonic lysates of urease-positive staphylococcus were highly active in comparison to cultures of intact organisms. There was no clear-cut correlation between drug susceptibility and phage sensitivity in the staphylococci studied. The sonic lysates of non-urease-producing Strep, pyogenes (Lancefield A) and enterococcus showed potent urease activity. Pneumococcus, which is a non-urease-producer, also exhibited urease activity in sonic lysates. Drug susceptibility did not correlate with urease activity in pathogenic gram-positive cocci. This was in contrast to the findings with coliform organisms.