Changes Occurring in Bacillus fusiformis During the Application of Penicillin

Abstract

WHILE investigating microscopically smears of 210 cases of ulcerative gingivitis we found the usual crowd of typical spirochætes and fusiform bacilli. Routine treatment with penicillin produced clinical and bacteriological clearance. In 41 cases the fusiform bacilli showed after treatment with penicillin a peculiar change in shape. Central round or spindle-shaped swellings (see accompanying illustration) of intensively stained plasma were found in varying numbers. These large swellings are obviously an expression of the influence on these micro-organisms by penicillin. These bodies were never observed in untreated cases, or in any other treatment of this condition. A study, of this appearance is in preparation.