Table 2.

Blood Culture Laboratory Diagnosis Organized by Etiological Agent

Etiologic Agents	Diagnostic Procedures	Optimum Specimens	Transport Issues
Staphylococcus spp Streptococcus sppEnterococcus spp Listeria monocytogenesEnterobacteriaceaePseudomonas spp Acinetobacter spp HACEKa bacteria Brucella spp Anaerobic bacteria	Adults: 2–4 blood culture sets per septic episode	20–30 mL of blood per culture set in adults injected into at least 2 blood culture bottlesb	Inoculated culture vials should be transported to the Laboratory ASAP at RT, organisms will usually survive in inoculated culture vials even if not incubated immediately
	Infants & children: ≥2 blood culture sets	Blood volume depends on the child’s weight (see Table 3)c
Bartonella spp	≥2 lysis-centrifugation (Isolator) blood culture tubesd	10 mL of blood should be inoculated directly into each lysis-centrifugation culture tube	Lysis-centrifugation culture tubes should be transported at RT to the laboratory ASAP and processed within 8 h of blood inoculation
	NAAT	5 mL of plasma	EDTA tube, RT, 2 h
	Serology for IgM/IgG antibodies	5 mL of serum	Clot tube; RT; 2 h
Legionella spp	2 or more lysis- centrifugation (Isolator) blood culture tubese	10 mL of blood should be inoculated directly into each lysis-centrifugation culture tube	Lysis-centrifugation culture tubes should be transported at RT to the laboratory ASAP and processed within 8 h of blood inoculation
	Legionella urine antigen test (for serotype 1)	10 mL of midstream, clean-catch urinef	Closed container, RT, 2 h
Coxiella burnetii	Coxiella IFA serology	5 mL of serum	Clot tube, RT, 2 h
	NAAT	5 mL of plasma	EDTA tube, RT, 2 h
Tropheryma whipplei	NAAT	5 mL of plasma	EDTA tube, RT, 2 h
Yeast	Adults: 2–4 blood culture sets (see above)	20–30 mL of blood per culture in adults injected into at least 2 blood culture bottlesg	Inoculated culture vials should be transported ASAP at RT to the laboratory for early incubation. Inoculated vials for direct detection of Candida spp by T2 magnetic resonance assay may be used [10].
	Infants and children: ≥2 blood culture sets (see above)	As much blood as can be conveniently obtained from children; volume depends on weight of childc	Organisms will usually survive in inoculated culture vials even if not incubated immediately. Malassezia spp require lipid supplementation; lysis-centrifugation is recommended for their recovery.
Filamentous and dimorphic fungih	≥2 lysis-centrifugation (Isolator) blood culture vials	10 mL of blood should be inoculated directly into each lysis-centrifugation culture vial	Lysis-centrifugation culture vials should be transported to the laboratory ASAP and processed within 8 h of blood inoculation.
Mycobacteria	3 cultures using AFB-specific blood culture bottles	5 mL of blood inoculated directly into AFB-specific blood culture bottle	Inoculated culture vials should be transported to the laboratory ASAP for early incubation.

Abbreviations: AFB, acid-fast bacilli; ASAP, as soon as possible; EDTA, ethylenediaminetetraacetic acid; IFA, indirect fluorescent antibody; IgG, immunoglobulin G; IgM, immunoglobulin M; NAAT, nucleic acid amplification test; RT, room temperature.

^aHACEK bacteria include Haemophilus (Aggregatibacter) aphrophilus, Haemophilus parainfluenzae, Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae.

^bTypically, blood specimens are split between aerobic and anaerobic blood culture bottles. There may be circumstances in which it is prudent to omit the anaerobic vial and split blood specimens between 2 aerobic vials. One example is when fungemia due to yeast is strongly suspected. Most manufacturers’ bottles accept a maximum of 10 mL per bottle.

^cRecommended volumes of blood for culture in pediatric patients are shown in (Table 3) [1].

^dThe success rate for recovery of Bartonella spp from blood even when optimum methods are used is extremely low.

^e Legionella bacteremia occurs infrequently and rarely is the organism recovered from blood even when optimum culture techniques are employed.

^fThe optimum urine specimen is the first voided specimen of the day.

^gSince yeast are highly aerobic, when fungemia due to yeast is suspected, it might be prudent within a series of blood cultures to inoculate at least 1 blood specimen into 2 aerobic vials rather than the customary aerobic and anaerobic vial pair. Alternatively, a broth medium designed for enhanced yield of yeast (eg, MycoF/Lytic [BD Diagnostics, Sparks, Maryland]) or lysis-centrifugation may be used.

^hSome dimorphic fungi and yeasts (eg, Malassezia spp) may be visualized on peripheral blood smears in some patients using one of a variety of fungal stains. Such requests should be made in consultation with the microbiology laboratory director.