Sign in →

Test Code CXBLD Culture, Blood

Performing Laboratory

North Ottawa Community Hospital

Specimen Requirements

Have patient report to North Ottawa Community Hospital Laboratory.

 

Specimen Type: Blood

Container/Tube: Aerobic and anaerobic culture bottles

Collection Instructions:

1. The number of separate blood cultures must be ordered  by the attending physician.

2. All blood cultures will be obtained under strict antiseptic and sterile procedures by laboratory personnel. It is preferred that all blood cultures be obtained before the administration of antibiotics.

3. When multiple blood cultures are ordered, the laboratory will draw multiple blood cultures from different sites consecutively.

4. Each culture will include 2 separate culture bottles, 1 which is for anaerobic and the other aerobic bacteria.

Additional Informtion: If the physician requests blood cultures for fungi, these must be requested as such and will determine the length of culture duration.

Reference Values

No growth aerobically or anaerobically in 5 days.

MIC Reference Values

NI (no interpretation)

In some instances, an interpretive category cannot be provided based on available data.

S (susceptible)

A category defined by a breakpoint that implies that isolates with an MIC at or below or a zone diameter at or above the susceptible breakpoint are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy.

SDD (susceptible-dose dependent)

A category defined by a breakpoint that implies that susceptibility of an isolate depends on the dosing regimen that is used in the patient. To achieve levels that are likely to be clinically effective against isolates for which the susceptibility testing results are in the susceptible-dose dependent (SDD) category, it is necessary to use a dosing regimen (ie, higher doses, more frequent doses, or both) that results in higher drug exposure than that achieved with the dose that was used to establish the susceptible breakpoint. Consideration should be given to the maximum literature-supported dosage regimens, because higher-exposure gives the highest probability of adequate coverage of a SDD isolate. The drug label should be consulted for recommended doses and adjustment for organ function.

I (intermediate)

A category defined by a breakpoint that includes isolates with MICs or zone diameters within the intermediate range that approach usually attainable blood and tissue levels and/or for which response rates may be lower than for susceptible isolates.

Note: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated or when a higher-than-normal dosage of a drug can be used. This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins.

R (resistant)

A category defined by a breakpoint that implies that isolates with an MIC at or above or a zone diameter at or below the resistant breakpoint are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate MICs or zone diameters that fall in the range in which specific microbial resistance mechanisms are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

Day(s) Test Set Up

Monday through Sunday

Specimen Transport Temperature

Ambient

Test Classification and CPT Coding

87040

If indicated, additional testing and charges may apply.

Methodology/Method Description

BacT/ALERT

Specimens are cultured to enriched and/or selective media appropriate to the anatomic location and the scope of microorganisms expected. Cultures are incubated for 3 to 7 days depending on the specimen source. Pathogens or possible pathogens are identified using conventional biochemical tests in combination with BioMerieux Vitek® 2 automated identification system. Susceptibility testing is performed using either the Vitek® 2 automated antimicrobial susceptibility testing system or manual disk diffusion susceptibility testing.

When antimicrobial susceptibility testing is performed, testing is performed on pure culture isolates of pathogenic (or potentially pathogenic) bacteria grown from specimens that have been appropriately collected, so as not to confuse clinically significant isolates with normal flora.

Antimicrobial susceptibility testing determines the minimal inhibitory concentration (MIC) value of selected antimicrobial agents against isolated potentially pathogenic bacteria. The MIC is the lowest antimicrobial concentration that inhibits growth of the bacterium. Clinical breakpoints (interpretive criteria) applied are published by Clinical and Laboratory Standards Institute (CLSI) M100-S30, 2020.