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HelpTest Code HPCRP Helicobacter pylori with Clarithromycin Resistance Prediction, Molecular Detection, PCR, Varies
Infectious
Ordering Guidance
This test uses isolates of Helicobacter pylori for testing. If testing directly from feces is desired, order HPFRP / Helicobacter pylori with Clarithromycin Resistance Prediction, Molecular Detection, PCR, Varies.
Additional Testing Requirements
1. If identification testing is needed; also order IDENT / Organism Referred for Identification, Aerobic Bacteria.
2. If susceptibility testing is needed; also order ZMMLS / Antimicrobial Susceptibility, Aerobic Bacteria, MIC, Varies.
Shipping Instructions
1. For shipping information see Infectious Specimen Shipping Guidelines.
2. Place specimen in a large infectious container and label as an etiologic agent/infectious substance, if appropriate.
Necessary Information
Organism identification and specimen source are required.
Specimen Required
Supplies: Infectious Container, Large (T146)
Container/Tube: Agar slant or other appropriate media
Specimen Volume: Isolate
Collection Instructions:
1. Perform isolation of Helicobacter pylori in culture.
2. H pylori isolate must be submitted in pure culture. Do not submit mixed cultures.
Useful For
Assessing pure isolates of Helicobacter pylori to predict clarithromycin resistance or susceptibility
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PCRID | Identification by PCR | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex test may be performed at an additional charge.
For more information see Helicobacter pylori Diagnostic Algorithm.
Special Instructions
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Reporting Name
H pylori + Clarithro Resist PCRSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Frozen | |||
| Refrigerated | |||
Reject Due To
| Agar plate ESwab Port-a-Cult |
Reject |
Clinical Information
Helicobacter pylori is the main cause of peptic ulcer disease and a risk factor for gastric cancer when left untreated. Traditionally, H pylori diagnosis has included noninvasive tests (eg, urea breath test, fecal antigen test) or invasive tests (eg, gastric biopsy). Antimicrobial resistance in H pylori is poorly studied but is rising, challenging its treatment. In 2012, an international clinical consortium study group recommended monitoring of clarithromycin resistance rates and ceasing its use at a threshold range of 15% to 20%.(1) Local monitoring has been practically impossible as not all patients undergo invasive testing, which yields a culture isolate that can be subjected to susceptibility testing. Even if invasive testing is performed, the organism can be difficult to isolate in culture and is highly fastidious once isolated, oftentimes not being amenable to phenotypic susceptibility testing. Further, there are only a handful of specialized clinical microbiology laboratories that perform H pylori susceptibility testing. In an internal study of local and referred isolates, clarithromycin resistance was observed to be most commonly due to A2143G (70/88 isolates, 79.6%), followed by A2142G (12/88 isolates, 13.6%) and A2142C (3/88 isolates, 3.4%) alterations in the 23S ribosomal RNA gene.(2) Overall, one of these alterations was found in 97% of clarithromycin-resistant H pylori isolates studied.
Reference Values
Not applicable
Interpretation
A detected result indicates the presence of Helicobacter pylori 23S ribosomal RNA gene; the presence or absence of the 3 most common 23S ribosomal RNA gene single nucleotide variations (A2143G, A2142G, and A2142C) is reported.
A not detected result indicates the absence of detectable H pylori DNA.
Cautions
This assay is used for testing of isolates of Helicobacter pylori. Request HPFRP / Helicobacter pylori with Clarithromycin Resistance Prediction, Molecular Detection, PCR, Feces if testing directly from feces is desired.
Potential cross-reactivity may occur with the following non-pylori Helicobacter species: Helicobacter acinonychis, Helicobacter cetorum, and Helicobacter mustalae (not been reported to cause disease in humans) and Helicobacter canis, Helicobacter cinaedi, Helicobacter bizzozeronii, and Helicobacter heilmannii (infrequently found in humans).
This assay examines the 3 most common 23S ribosomal RNA point variants associated with clarithromycin resistance in H pylori. Other mechanisms of clarithromycin resistance are not assessed, nor are mechanisms of resistance to non-clarithromycin antimicrobial agents. The ZMMLS / Antimicrobial Susceptibility, Aerobic Bacteria, Varies assay is preferentially recommended for culture isolates to define a fuller spectrum of antimicrobial susceptibility (ie, to include antimicrobial agents beyond clarithromycin).
Day(s) Performed
Monday through Friday
Report Available
3 to 4 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
87150
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HPCRP | H pylori + Clarithro Resist PCR | 88509-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| HPS2 | Specimen Source | 31208-2 |
| HPORG | Organism Identified by Client | In Process |
| 608005 | Helicobacter pylori Result | 49101-9 |
| 608006 | Clarithromycin Resistance Result | 88509-5 |
Forms
If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen