Septicemia Flashcards
Bacteremia Definition
The presence of bacteria in the blood. Disease may or may not be present.
Agents of Septicemia infection
Staph., Strep., Enterococcus, E. coli, Enterobacteriaceae, Yeast
Septicemia Definition
Bacteria, or their toxins, are causing harm to the host. Disease is present.
Primary Bacteremia
Endovascular source such as infected cardiac valve or intravenous catheter
Secondary Bacteremia
Extravascular source such as lungs in pneumonia
Classification of Bacteremia by Microbiology
- G+
- G-
- Anaerobic
- Polymicrobial (enterococci and G- mixture from gut)
Classification of bacteremia by place of acquisition
- Community
- Nosocomial
Classification of Bacteremia by Duration
- Transient
- Intermittent
- Continuous
Intermittent Causes of Septicemia
Meningococcemia, gonococcemia, pneumonia
Continuous Causes of Septicemia
Endovascular source like endocarditis and infected catheters
Intravascular Septicemia
Originating in the cardiovascular(CV) system:
- Infective endocarditis
- Intravenous, catheter-associated
Extravascular Septicemia
Originating outside the CV system and entering the bloodstream via lymphatic system.
- GU tract (25%)
- Respiratory tract (20%)
- Abcesses/Surgical wounds (15%)
- Others (35%)
Specimen Collection and Transport
- Collect 2-3 specimens per 24 hours
- Specimens collection should not be closer than 3 hrs
- Draw 10 mL from two separate venipuncture sites.
- Specimen should be transported at room temp. within 2 hours
Minimum Microbe Presence for Septicemia Diagnosis
Adults: usually
Blood Culture Media
Sodium polyanethol sulfonate (SPS 0.03%), the most common anticoagulant used. Maintain a ratio of 1:5 (blood to broth medium)
Manual Blood Culture Detection Methods (Conventional)
- Visual inspection
- Blind subculture
Manual Blood Culture Detection Methods (Septi-check)
- Biphasic media
- Self-subculturing
- Poor anaerobe recovery
Manual Blood Culture Detection Methods (Isolator)
A lysis-centrifugation system
- Blood lysed by saponin
- Centrifuged
- Inoculated directly to media
Automated Blood Culture Detection Methods
- Continuous shaking of bottles
- Continuous monitoring for positives (yellow color indicates this)
- Variety of media formulations
- Barcode driven
Differentiating Septicemia and Contamination
- Multiple bottles would be positive versus only single bottle in case of a contamination.
- Isolation of same organism in blood and from a sterile site simultaneously.
- Isolation of members of Enterobacteriaceae, S. aureus, P. aeruginosa, S. Pneumoniae, H. influenzae, C. albicans always indicate an infection.
- Most common contaminants are Propionobacterium acnes, diphtheroids and Staphylococcus coagulase-negative species.
- For slow-growers, keep the cultures longer (upto 4 weeks).
Rapid Detection of mecA
Oxoid’s RAPID PBP2* TEST, a latex agglutination test Velogen’s cycling probe assay Cepheid’s Smart Cycler assay Advandx PNA FISH
