A STUDY ON THE CHARACTERIZATION OF CORYNEBACTERIUM ACNES

Abstract

Forty-nine strains of anaerobic gram-positive rods were used in a systematic study of their biochemical and physiological reactions and morphological characteristics and were also subjected to gas chromatographic analyses in an effort to classify them as strains of Corynebacterium acnes (C. acnes). The strains were isolated both from lesions in acne vulgaris and from normal skin. According to their biochemical and physiological characters, these 49 strains were divided into six subgroups (Subgroup A-F). They were also separated into two morphological types. The larger of these two types included gram-positive, unevently staining pleomorphic rods (35 strains); the smaller type contained shorter coccal rods similar to Peptostreptococci (14 strains). The macroscopic appearance of the colonies of both types was the same. All strains of the smaller type showed the same biochemical and physiological characteristics which were of the saccharolytic type (Subgroup B) suggesting a close relationship between the microscopic appearance of the strains and their biochemical and physiological characteristics. Upon microscopical observation, the changing the pH of the media did not cause any transformation of the organism from one type to another. Between pH 6.0 and 6.5 all strains grew well but above pH 8.0 growth was poor. The gas chromatographic analyses demonstrated that selected sample strains from each of the six subgroups showed the same characteristic chromatograph, suggesting that they could be of the same species, i.e., C. acnes.

Biotyping of Propionibacterium acnes isolated from normal human facial skin

“…Cummins and Johnson found that sorbitol fermentation was useful for the assay of serotypes of P. acnes (2). However, the substantial proportion of strains of serotype I were usually sorbitol fermentation negative (2,8,14). In our study also, only 54% of the strains of serotype I were sorbitol fermentation positive.…”

“…Three reports on biotyping of P. acnes have appeared in the literature (10,13,14). However, strains of P. granulosum were confused with P. acnes, as in the case of serotyping.…”

“…Although an abundance of data on biochemical and serological studies of Propionibacterium acnes has been accumulated, there still remains a great deal of confusion regarding criteria for classifying the bacteria, and other species such as P. granulosum are often mistakenly included in the group (1,(9)(10)(11)(12)(13)(14)19).…”

New medium for isolating propionibacteria and its application to assay of normal flora of human facial skin

“…Indole, nitrate, milk, and gelatin hydrolysisnegative P. acnes isolates have been reported by other investigators (7,10,12,21), but in our present work, these reactions were positive on all isolates of P. acnes. On the other hand, these reactions were negative on all isolates of P. granulosum.…”

“…For example, the diluent for aerobes first described by Williamson and Kligman (26) has been used for isolation of propionibacteria without further examination of the suitability of the composition and of the conditions used. Although the problems pertaining to the taxonomy of Propionibacterium acnes were largely dealt with by Johnson and Cummins in 1972 (2, 8, 13-15, 18, 20), it is apparent in the literature that there are circumstances in which Propionibacterium granulosum are often confused with P. acnes (1,21,24,25).…”