Thibodeau Alexandre, Fravalo Philippe, Taboada Eduardo N, Laurent-Lewandowski Sylvette, Guévremont Evelyne, Quessy Sylvain, Letellier Ann
Department of Pathology and Microbiology, NSERC Industrial Research Chair in Meat-Safety (CRSV), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada.
Department of Pathology and Microbiology, Swine and Avian Infectious Disease Research Centre (CRIPA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada.
BMC Microbiol. 2015 May 10;15:97. doi: 10.1186/s12866-015-0433-5.
Campylobacter jejuni is responsible for human foodborne enteritis. This bacterium is a remarkable colonizer of the chicken gut, with some strains outcompeting others for colonization. To better understand this phenomenon, the objective of this study was to extensively characterize the phenotypic performance of C. jejuni chicken strains and associate their gut colonizing ability with specific genes.
C. jejuni isolates (n = 45) previously analyzed for the presence of chicken colonization associated genes were further characterized for phenotypic properties influencing colonization: autoagglutination and chemotaxis as well as adhesion to and invasion of primary chicken caecal cells. This allowed strains to be ranked according to their in vitro performance. After their in vitro capacity to outcompete was demonstrated in vivo, strains were then typed by comparative genomic fingerprinting (CGF). In vitro phenotypical properties displayed a linear variability among the tested strains. Strains possessing higher scores for phenotypical properties were able to outcompete others during chicken colonization trials. When the gene content of strains was compared, some were associated with different phenotypical scores and thus with different outcompeting capacities. Use of CGF profiles showed an extensive genetic variability among the studied strains and suggested that the outcompeting capacity is not predictable by CGF profile.
This study revealed a wide array of phenotypes present in C. jejuni strains, even though they were all recovered from chicken caecum. Each strain was classified according to its in vitro competitive potential and its capacity to compete for chicken gut colonization was associated with specific genes. This study also exposed the disparity existing between genetic typing and phenotypical behavior of C. jejuni strains.
空肠弯曲菌是人类食源性肠炎的病原体。这种细菌是鸡肠道中的显著定植菌，一些菌株在定植方面比其他菌株更具竞争力。为了更好地理解这一现象，本研究的目的是广泛表征空肠弯曲菌鸡源菌株的表型特征，并将它们的肠道定植能力与特定基因联系起来。
先前已分析过是否存在与鸡定植相关基因的空肠弯曲菌分离株（n = 45），进一步针对影响定植的表型特性进行了表征：自凝作用、趋化性以及对鸡盲肠原代细胞的黏附和侵袭。这使得菌株能够根据其体外性能进行排名。在体内证明其体外竞争能力后，通过比较基因组指纹图谱（CGF）对菌株进行分型。在测试菌株中，体外表型特性呈现出线性变化。在鸡定植试验中，表型特性得分较高的菌株能够胜过其他菌株。当比较菌株的基因含量时，一些菌株与不同的表型得分相关，因此与不同的竞争能力相关。使用CGF图谱显示，所研究的菌株之间存在广泛的遗传变异性，并且表明竞争能力无法通过CGF图谱预测。
本研究揭示了空肠弯曲菌菌株中存在的广泛表型，尽管它们均从鸡盲肠中分离得到。每个菌株根据其体外竞争潜力进行分类，并且其在鸡肠道定植中的竞争能力与特定基因相关。本研究还揭示了空肠弯曲菌菌株的基因分型与表型行为之间存在的差异。
