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Culture, Blood with Reflex Molecular Identification

Test code: 13954

The Culture, Blood with Reflex Molecular Identification test detects bacteria in a whole-blood sample to help diagnose bacteremia. In this test, samples from patients suspected of sepsis are collected in aerobic and anaerobic blood culture bottles, and a standard blood culture is performed. If a blood culture result is positive, a Gram stain is performed to determine if the organism is gram negative or gram positive.

Based on the Gram stain result, either the gram-negative or gram-positive blood culture identification (BCID) panel will be performed using media from the positive blood culture bottle. These panels are qualitative, multiplexed molecular assays that use microarray technology to simultaneously detect and identify either gram-negative or gram-positive organisms and selected antimicrobial (AMR) resistance genes. The results of the blood culture and (if performed) Gram stain, BCID, conventional identification, and susceptibility testing are reported. 

The BCID panel detects several common gram-positive and gram-negative organisms that are associated with sepsis as well as antimicrobial resistance (AMR) targets. The specific organisms and AMR targets that are detected are shown in Table 1.1,2

Table showing Blood Culture Molecular Identification (BCID) panel targets.

(click the table to enlarge it in a new window)

Note: Definition of spp - species or species plural respectively

Yes, the BCID panel is performed using the media from a positive blood culture bottle. Based on the results on the Gram stain, either the gram-positive or gram-negative panel will be utilized. If a mixture of gram-negative and gram-positive organisms is seen on the Gram stain, both panels will be utilized. 

The BCID result should be available within 3 hours of blood culture bottle being positive and BCID test setup.

The Gram stain/culture result and the BCID result may not match for several reasons. The most likely cause is the organism observed on the Gram stain or culture is not detected by the BCID panel (refer to Question 2).

Another possibility is that the organism may no longer be viable to recover on culture (eg, Streptococcus pneumoniae). Finally, certain BCID probes may cross-react with other bacteria; for example, Staphylococcus species probes may cross-react with Aerococcus species.

References

  1. VERIGENE® Gram-Negative Blood Culture Nucleic Acid Test (BC-GN) Package Insert.89-30000-00-776 Rev B. 12/2020.
  2. VERIGENE® Gram-Positive Blood Culture Nucleic Acid Test (BC-GP) Package Insert.89-30000-00-782 Rev B. 12/2020.

 

 

This FAQ is provided for informational purposes only and is not intended as medical advice. A physician’s test selection and interpretation, diagnosis, and patient management decisions should be based on the physician’s education, clinical expertise, and assessment of the patient.

 

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