Helicobacter pylori Isolation and Antibiotic Susceptibility Testing Using Rapidly Frozen Biopsy Samples

Area of Science:

• Microbiology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Centralized laboratory analysis of tissue samples is crucial for institutions lacking susceptibility testing capabilities.
• Long-term storage of biopsy specimens is essential for isolating bacteria like Helicobacter pylori (H. pylori).

Purpose of the Study:

• To assess the feasibility of isolating H. pylori and performing antibiotic susceptibility testing on rapidly frozen biopsy specimens.
• To evaluate the effectiveness of a centralized approach for H. pylori diagnostics across multiple institutions.

Main Methods:

• Eight institutions in Korea participated, collecting stomach biopsy samples from patients undergoing endoscopy.
• One biopsy was rapidly frozen at -80°C for central lab analysis; the other used for rapid urease testing.
• H. pylori was isolated from frozen samples under microaerophilic conditions, and Minimum Inhibitory Concentrations (MICs) were determined using agar dilution.

Main Results:

• Out of 113 patients with positive rapid urease tests, 87 H. pylori strains (77.0% success rate) were successfully isolated from frozen samples.
• Antibiotic resistance rates were observed for amoxicillin (23.0%), clarithromycin (25.3%), metronidazole (28.7%), tetracycline (1.1%), levofloxacin (33.3%), and ciprofloxacin (34.5%).

Conclusions:

• H. pylori isolation and antibiotic susceptibility testing are feasible using rapidly frozen and transported biopsy specimens.
• This method supports centralized diagnostic capabilities for H. pylori, overcoming limitations of local testing infrastructure.