TABLE 3.

Comparative yield of clinically important isolates in FN versus SN anaerobic blood culture bottles from patients on antimicrobial therapy

Microorganism	No. of isolates detected by:			P value
	Both bottles	FN only	SN only
Gram-positive bacteria
Staphylococcus aureus	72	140	6	<0.001
Coagulase-negative staphylococci	45	24	16	NSa
Streptococcus spp.b	8	2	2	NS
Enterococcus spp.c	38	13	7	NS
Bacillus sp.	0	1	0	NS
Gram-negative bacilli
Enterobacteriaceaed	35	25	7	<0.005
Other gram-negative bacillie	4	1	8	<0.05
Anaerobic bacteriaf	2	7	2	NS
Yeastsg	0	0	6	<0.05
All microorganisms	204	213	54	<0.001

^aNS, not significant (P > 0.05).

^bIncludes five isolates of Streptococcus pneumoniae, four of Streptococcus pyogenes, two of viridans group streptococci, and one of Streptococcus agalactiae.

^cIncludes 47 of Enterococcus faecalis, 10 of Enterococcus faecium, and 1 of Enterococcus sp.

^dIncludes 23 of Klebsiella pneumoniae; 16 of Escherichia coli; 8 of E. cloacae; 7 of Salmonella spp.; 3 of Enterobacter aerogenes; 3 of Klebsiella oxytoca; 3 of Serratia marcescens; and 1 each of Ewingella americana, Morganella morganii, Providencia stuartii, and Serratia liquefaciens.

^eIncludes 10 of P. aeruginosa, 1 of A. baumannii, 1 of Oligella sp., and 1 of Haemophilus influenzae.

^fIncludes three of Bacteroides fragilis; three of Clostridium clostridioforme; two of the Bacteroides fragilis group; and one each of Clostridium difficile, Clostridium ramosum, and Bacteroides distasonis.

^gIncludes two of Candida glabrata, two of C. parapsilosis, and one each of Candida albicans and Candida tropicalis.