PC2 1.1.2 Blood Cultures

bacteremia

microorg

sepsis

microorg + symptoms

primary infection

no evidence

secondary infection

isolated from another site

hypothermic

<36 C (97 F)

hyperthermic

> 38 C (100 F)

neutropenia

< 1,500 neutrophils/mcL of blood

leukocytosis

> 10,000 WBCs/mcL of blood

max blood vol. in each bottle

10 ml

when choosing blood volume for children, we use their ___________

weight

the amount of blood for children is ______% of their blood volume

2-4%

preferred site for blood culture

peripheral venipuncture

overfilling can cause

false positive

variables that can impact purity of sample (3)

1) skin antiseptic

2) bottle prep

3) vascular catheter

common contaminates (4)

1) coag. neg. staph

2) corynebacterium sp,

3) micrococcus

4) bacillus (not anthrax)

coag. neg. staph, corynebacterium sp & micrococcus are common ______ colonizers

skin

bacillus sp. are common ______________ contaminants

environmental

blood agar grows what organisms?

all

blood agar helps differentiate...

hemolytics

chocolate agar grows what organisms?

fastidious

chocolate agar is brown because...

made of lysed RBCs

examples of fastidious orgs (2)

neisseria

haemophilus

macconkey agar grows what organisms?

gram neg

macconkey agar has _________ to inhibit gram pos orgs

bile salts

mueller-hinton agar is used for...

antimicrobial susceptibility

time to positive (TTP) for most organisms is...

48H

testing steps (6)

1) collection

2) incubation

3) gram stain

4) film array

5) media streak & incubate

6) automated system for bacteria susceptibility testing