LUNAM Université, Oniris, UMR 1300 Biologie, épidémiologie et analyse des risques, Nantes F-44307, France.
Vet Microbiol. 2011 Dec 29;154(1-2):171-9. doi: 10.1016/j.vetmic.2011.07.002. Epub 2011 Jul 23.
Campylobacter, a leading cause of food-borne illness worldwide, has a widespread distribution with a broad range of animal hosts and environmental reservoirs. The genetic description of bacterial strains is a powerful tool for epidemiological studies but can be impaired by the high genomic variability of Campylobacter. Our study aimed (i) at investigating the genotypic instability of Campylobacter generated either in vitro by subculturing or after in vivo passage on specific pathogen-free pigs and (ii) at evaluating the suitability of typing methods to detect such variation. Pigs were inoculated per os with three Campylobacter strains (one C. coli originating from pig faeces, one C. jejuni and one C. coli originating from poultry faeces) alone or in mixture and non-inoculated pigs were housed in adjacent pens. Genotypic instability was investigated using both macrorestriction combined with pulsed-field gel electrophoresis analysis (PFGE) and PCR restriction fragment length polymorphism analysis of the flaA gene (flaA PCR-RFLP). No variability in the genetic profile was observed for the three strains maintained through twenty times subculturing events in vitro. Genotypic variability was evidenced in vivo only in pigs inoculated with C. coli of porcine origin, either alone or in a mix, with both genotyping methods. In our study, for one porcine C. coli strain, 13% and 21% of variability were generated in the digestive tract of pigs by PFGE and flaA PCR-RFLP typing methods, respectively. This study is a first approach for a better understanding of the genomic instability of Campylobacter in pig under field conditions.
空肠弯曲菌是全球食源性疾病的主要致病菌之一，它在动物宿主和环境中有广泛的分布和广泛的储存库。细菌株的遗传描述是流行病学研究的有力工具，但可能会受到空肠弯曲菌基因组高度变异的影响。我们的研究旨在：（i）调查体外连续传代或在特定无病原体猪体内传代后空肠弯曲菌产生的基因型不稳定性；（ii）评估分型方法检测这种变异的适用性。猪经口接种三种空肠弯曲菌菌株（一种来自猪粪便的 C. coli，一种 C. jejuni 和一种来自家禽粪便的 C. coli）单独或混合接种，未接种的猪则被安置在相邻的围栏中。使用宏限制结合脉冲场凝胶电泳分析（PFGE）和 flaA 基因的 PCR 限制性片段长度多态性分析（flaA PCR-RFLP）两种方法研究基因型不稳定性。在体外连续传代二十次后，三种菌株的遗传谱没有发生变化。只有在单独或混合接种来自猪源的 C. coli 的猪体内才观察到体内的基因型可变性，两种基因分型方法都证明了这一点。在我们的研究中，对于一种猪源 C. coli 菌株，PFGE 和 flaA PCR-RFLP 分型方法分别在猪的消化道中产生了 13%和 21%的可变性。本研究首次探讨了在田间条件下猪空肠弯曲菌基因组不稳定性的情况。
