Stability of the genotype of Campylobacter jejuni under controlled culture conditions
Genotypische stabiliteit van Campylobactr jejuni onder gecontroleerde kweekcondities
26 May 2012, PDF |
26 pages |
Ritmeester WS, Delfgou-van Asch EHM, de Jonge R
RIVM Report 251825003
Campylobacter (C.) jejuni is identified as the major cause of bacterial gastro-enteritis in the Netherlands. Although poultry is considered as the main source of C. jejuni, many strains found in poultry (identified by various genotyping techniques) cannot be traced in the human population and in the Netherlands, of all human isolates, only 30% has been detected in poultry. Variations in genotype due to mutations or exchange of DNA might underlie these observations. This study was undertaken to monitor changes in genotype of C. jejuni. We cultured C. jejuni for approximately 150 generations in nutrient rich medium in the absence of exchangeable DNA under various microaerobic conditions. Alterations in genotype were studied by pulsed field gel electrophoresis (PFGE), amplified fragment length polymorphism (AFLP) and the multi locus sequence typing (MLST) technique. No rearrangements, inserts or deletions of large DNA fragments were detected. PFGE and AFLP patterns of cultures at start were indistinguishable from cultures 150 generations later. No mutations were observed in any of the restriction sites and no detectable mutations had occurred in the loci subjected to MLST analysis. In the absence of exchangeable DNA under constant culture conditions the genotype of C. jejuni appeared to be stable.