“…The first material discovered to have sulfonamide-antagonistic properties was peptone (15,91,157,177,205). 23 Lockwood and Lynch (159) showed that this phenomenon is general, peptone being antagonistic to SA, SP, and ST in the case of pneumococci, staphylococci, colon bacilli and hemolytic streptococci. According to Lockwood (157), bacteria under the influence of sulfonamide are unable to break down complex protein but are still able to utilize for growth simple protein-split products, such as peptone.…”