Campylobacter jejuni is a major foodborne pathogen that causes gastroenteritis in humans. Chickens act as the reservoir host for C. jejuni, wherein the pathogen asymptomatically colonizes the ceca leading to contamination of carcasses during slaughter. The major colonization factors in C. jejuni include motility, intestinal epithelial attachment, acid/bile tolerance, and quorum sensing. Reducing the expression of the aforementioned factors could potentially reduce C. jejuni colonization in chickens. This study investigated the efficacy of subinhibitory concentration (SIC; compound concentration not inhibiting bacterial growth) of carvacrol in reducing the expression of C. jejuni colonization factors in vitro. Moreover, the effect of carvacrol on the expression of C. jejuni proteome was investigated using liquid chromatography-tandem mass spectrometry. The motility assay was conducted at 42°C, and the motility zone was measured after 24 h of incubation. For the adhesion assay, monolayers of primary chicken enterocytes (∼105 cells/well) were inoculated with C. jejuni (6 log cfu/well) either in the presence or absence of carvacrol, and the adhered C. jejuni were enumerated after 90 min of incubation at 42°C. The effect of carvacrol on C. jejuni quorum sensing and susceptibility to acid/bile stress was investigated using a bioluminescence assay and an acid-bile survival assay, respectively. The SIC (0.002%) of carvacrol reduced the motility of C. jejuni strains S-8 and NCTC 81-176 by ∼50 and 35%, respectively (P < 0.05). Carvacrol inhibited C. jejuni S-8 and NCTC 81-176 adhesion to chicken enterocytes by ∼0.8 and 1.5 log cfu/mL, respectively (P < 0.05). Moreover, carvacrol reduced autoinducer-2 activity and increased the susceptibility of C. jejuni to acid and bile in both the strains (P < 0.05). Liquid chromatography-tandem mass spectrometry revealed that the SIC of carvacrol reduced the expression of selected C. jejuni colonization proteins critical for motility (methyl-accepting chemotaxis protein), adhesion (GroL), growth and metabolism (AspA, AcnB, Icd, Fba, Ppa, AnsA, Ldh, Eno, PurB-1), and anaerobic respiration (NapB, HydB, SdhA, NrfA) (P < 0.05). Results suggest the mechanisms by which carvacrol could reduce C. jejuni colonization in chickens.

中文翻译：

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香芹酚减弱了空肠弯曲杆菌的定居因子和蛋白质组，对鸡肠内的持久性至关重要。

空肠弯曲菌是一种主要的食源性病原体，可引起人类胃肠炎。鸡充当空肠弯曲杆菌的宿主宿主，其中病原体无症状地定殖在盲肠中，导致屠宰过程中contamination体受到污染。空肠弯曲菌的主要定居因素包括运动性，肠上皮附着，酸/胆汁耐受性和群体感应。减少上述因素的表达可能潜在地减少鸡中空肠弯曲杆菌的定殖。这项研究调查了香芹酚的亚抑制浓度（SIC；化合物浓度不抑制细菌生长）在体外降低空肠弯曲杆菌定居因子表达的功效。此外，香芹酚对C表达的影响。用液相色谱-串联质谱法研究了空肠蛋白质组。在42℃下进行活力测定，并且在孵育24小时后测量活力区。对于粘附力测定，在存在或不存在香芹酚的情况下，将单层初级鸡肠细胞（约105个细胞/孔）接种空肠弯曲杆菌（6 log cfu /孔），并在90分钟后计数粘附的空肠弯曲杆菌在42℃下孵育的时间。香芹酚对空肠弯曲杆菌群体感测和酸/胆汁胁迫敏感性的影响分别使用生物发光测定法和酸-胆汁存活测定法进行了研究。香芹酚的SIC（0.002％）使空肠弯曲杆菌S-8和NCTC 81-176的活力分别降低了约50％和35％（P <0.05）。香芹酚抑制空肠弯曲杆菌S-8和NCTC 81-176粘附于鸡肠细胞的能力约为0。分别为8和1.5 log cfu / mL（P <0.05）。此外，香芹酚降低了这两种菌株中autoinducer-2的活性，并提高了空肠弯曲杆菌对酸和胆汁的敏感性（P <0.05）。液相色谱-串联质谱分析表明，香芹酚的SIC降低了对空肠弯曲杆菌定殖蛋白（对甲基的趋化蛋白），黏附（GroL），生长和代谢（AspA，AcnB，Icd，Fba， Ppa，AnsA，Ldh，Eno，PurB-1）和无氧呼吸（NapB，HydB，SdhA，NrfA）（P <0.05）。结果表明香芹酚可以减少鸡空肠弯曲杆菌定植的机制。05）。液相色谱-串联质谱分析表明，香芹酚的SIC降低了对空肠弯曲杆菌定殖蛋白（对甲基的趋化蛋白），黏附（GroL），生长和代谢（AspA，AcnB，Icd，Fba， Ppa，AnsA，Ldh，Eno，PurB-1）和无氧呼吸（NapB，HydB，SdhA，NrfA）（P <0.05）。结果表明香芹酚可以减少鸡空肠弯曲杆菌定植的机制。05）。液相色谱-串联质谱分析表明，香芹酚的SIC降低了对空肠弯曲杆菌定居蛋白的表达，这些蛋白对运动性（接受甲基的趋化蛋白），黏附性（GroL），生长和代谢（AspA，AcnB，Icd，Fba， Ppa，AnsA，Ldh，Eno，PurB-1）和无氧呼吸（NapB，HydB，SdhA，NrfA）（P <0.05）。结果表明香芹酚可以减少鸡空肠弯曲杆菌定植的机制。