. 2005 Jan;49(1):77–81. doi: 10.1128/AAC.49.1.77-81.2005

TABLE 2.

Characteristics of vancomycin-resistant organisms isolated from five fecal specimens that contained vanB genes after anaerobic subculture, but no easily identifiable VRE, by routine methods

Specimen	Isolate	Gram stain result	Identification based on 16S rRNA gene (accession no.)	% Sequence identity
1	MLG856-1	Positive, bacillus	Clostridium hathewayi (AJ311620)	98
	MLG856-2	Positive, coccus	Enterococcus faecium (AF070223)	99
2	MLG480	Negative,^a bacillus	Clostridium innocuum (AF028352)	91
3	MLG080-1	Variable,^a bacillus^a	Clostridium bolteae (AJ08452)	98
	MLG080-3	Variable, coccobacillus^b	Ruminococcus lactaris (L76602)	91
4	MLG392	Positive, bacillus	Clostridium hathewayi (AJ311620)	98
5	MLG661	Positive, bacillus	Clostridium hathewayi (AJ311620)	98

Not all species classified in the genus Clostridium stain gram positive, and staining may vary depending on the medium used and the age of the culture (15).

Anaerobic gram-positive cocci may be elongated and resemble coccobacilli and lose their positivity with age (20).