Table 1.

Prevalence of P. acnes identified with anaerobic culture and 16S rDNA PCR examination.

	Total numbers	Discs with P. acnes		Discs with unidentified bacteria		Discs without any bacteria
		Disc only	Disc and muscle both	Disc only	Disc and muscle both
16S rDNA PCR	76	16	4	2	1	53
Gram-staining		Rod-like Gram-positive bacterium	Rod-like Gram-positive bacterium	N/A	N/A
Positive rates		21.05%	5.26%	2.63%	1.32%	69.74%