Detection of H. pylori and resistance to clarithromycin

Test description

Real-time multiplex PCR, after extraction of nucleic acids from a homogenate of a gastric biopsy or from a bacterial suspension.

Purpose of the test

Detection of H. pylori and clarytromycin resistance. 

Criteria for performing this test in the context of reference activities

Diagnosis of Helicobacter pylori infection or therapeutic failure of eradication therapy.

Instructions for samples

• Biopsy during endoscopy: optimally two biopsies (one antral and one fundus).
• Immediately place the biopsies in transport medium (remove any swabs!). 
• Inoculate the biopsy deep into the transport medium.

Instructions for transport

• Same recommendation as for culturing gastric biopsies on selective media:
• If sent directly to the laboratory and inoculated within 4 hours → Biopsy in a sterile tube containing 1-2 ml of sterile physiological water at 4°C.
• If delivery time is between 4 and 24 hours → Preserved biopsy in a suitable transport medium (e.g. Amies agar media, Portagerm pylori, bioMérieux) kept at 4°C.
• If delayed more than 24 hours → Biopsy frozen at -20°C, but preferably at -80°C in a suitable transport medium (see previous point) and transported in dry ice (or liquid nitrogen). 

Unacceptable requests

• Unsuitable sample (gastric lavage)
• Sample unidentified or sample with identification errors
• Mandatory fields on the application form incomplete,
• Clearly unsuitable storage conditions, transport conditions or result barring consequence

Turn around time (and frequency of analysis)

Testing is performed every day of the week. The result is sent after validation by the biologist. HP-negative and HP-positive clarithro-S results are available within 5 working days. Complete agar culture susceptibility test results for clarithro-R HP positives can take up to 3 weeks.

Reporting of test results

A protocol is sent to the requesting laboratory by mail.