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HelpTest Code CXSTL Culture, Stool
Performing Laboratory
North Ottawa Community Hospital
Specimen Requirements
Specimen must arrive within 24 hours of collection.
Specimen Type: Stool
Container/Tube: Screw-capped container with Cary-Blair transport medium
Specimen Volume: Adequate amount
Collection Instructions: Label container with patient’s name, date of birth, an
Additional Information: Stools for culture, ova and parasite or other testing should be submitted into he appropriate preservatives contained in our stool collection kits. If it is not possible to obtain collection kits prior to the stool collection, a clean, covered container is acceptable as long as it is refrigerated and transferred to preservative within the time period as follows:
1. Culture specimen must be set up within 2 hours or transferred to a Modified Cary-Blair based transport media.
2. Ova and Parasite testing requires the specimen be transferred to SAF and PVA vials within 2 hours.
3. C. difficile testing must be refrigerated within 24 hours of collection.
4. Giardia and cryptosporidium antigen testing must be transferred to ETM or SAF within 48 hours.
REJECT:
1. Stools contaminated with urine or Barium.
2. Stools that have sat out at room temp. for a period greater than that mentioned above.
3. With the exception of C. dificile testing, in-patient stool cultures should not be performed 3 days after hospitalization.
4. Stools for parasitology should not be performed after 4 days of hospitalization.
5. No more than 2 bacteriology specimens and 3 parasitology specimens should be processed on all out-patients without consultation with the lab director.
Specimen Transport Temperature
Refrigerated
Reference Values
Negative for enteric pathogens Campylobacter, Escherichia coli O157:H7, Salmonella, shiga toxin, Shigella, Vibrio, or Yersinia.
Day(s) Test Set Up
Monday through Sunday
Methodology
Conventional Culture Technique
Includes Escherichia coli O157:H7, Salmonella, shiga toxins, Campylobacter antigen, Shigella, Vibrio, and Yersinia.
Method Description
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.
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.
Test Classification and CPT Coding
87015-Concentration (any type), for infectious agents
87045-Salmonella/Shigella
87046 -Additional pathogens
87899 -Campylobacter antigen
87899 x 2-Shiga toxins
If indicated, additional testing and charges may apply.