Biphasic culture system for rapid Campylobacter cultivation

Area of Science:

• Microbiology
• Bacteriology

Background:

• Campylobacter jejuni is a significant human pathogen.
• Efficient cultivation methods are crucial for studying Campylobacter.

Purpose of the Study:

• To develop and evaluate a biphasic culture system for improved Campylobacter jejuni cultivation.
• To determine optimal conditions for growth, including media composition and gas phase.

Main Methods:

• A biphasic culture system using brucella agar and broth was developed.
• Variations included air or a specific gas mixture, with or without supplements (ferrous sulfate, sodium metabisulfite, sodium pyruvate).
• Growth was assessed with varying inoculum sizes, and cell morphology and motility were observed.

Main Results:

• All tested conditions supported growth of Campylobacter jejuni with a large inoculum (≥10^6 cells/ml).
• Supplemented media (FB/FAa) allowed reduction of inoculum to 100 cells/ml.
• Adjusted gas phases (BB/BAg, FB/FAg) enabled near-optimal growth from 1-10 cells/ml.
• Generation time was approximately 90 minutes, with cells retaining spiral morphology and motility.
• Cryopreservation in 15% glycerol allowed for ready recovery of all tested strains.

Conclusions:

• The developed biphasic culture system, particularly with supplemented media and controlled gas phases, significantly improves Campylobacter cultivation efficiency.
• This method is effective for both stock strains and fresh isolates.
• Cryopreservation protocols ensure long-term viability and recoverability of Campylobacter strains.