Wagle Basanta R, Upadhyay Abhinav, Arsi Komala, Shrestha Sandip, Venkitanarayanan Kumar, Donoghue Annie M, Donoghue Dan J
Department of Poultry Science, University of Arkansas, FayettevilleAR, USA.
Department of Animal Science, University of Connecticut, StorrsCT, USA.
Front Microbiol. 2017 Apr 6;8:599. doi: 10.3389/fmicb.2017.00599. eCollection 2017.
is one of the major foodborne pathogens that result in severe gastroenteritis in humans, primarily through consumption of contaminated poultry products. Chickens are the reservoir host of , where the pathogen colonizes the ceca, thereby leading to contamination of carcass during slaughter. A reduction in cecal colonization by would directly translate into reduced product contamination and risk of human infections. With increasing consumer demand for antibiotic free chickens, significant research is being conducted to discover natural, safe and economical antimicrobials that can effectively control colonization in birds. This study investigated the efficacy of in-feed supplementation of a phytophenolic compound, β-resorcylic acid (BR) for reducing colonization in broiler chickens. In two separate, replicate trials, day-old-chicks (Cobb500; = 10 birds/treatment) were fed with BR (0, 0.25, 0.5, or 1%) in feed for a period of 14 days ( = 40/trial). Birds were challenged with a four-strain mixture of (∼10 CFU/ml; 250 μl/bird) on day 7 and cecal samples were collected on day 14 for enumerating surviving in cecal contents. In addition, the effect of BR on the critical colonization factors of (motility, epithelial cell attachment) was studied using phenotypic assay, cell culture, and real-time quantitative PCR. Supplementation of BR in poultry feed for 14 days at 0.5 and 1% reduced populations in cecal contents by ∼2.5 and 1.7 Log CFU/g, respectively ( < 0.05). No significant differences in feed intake and body weight gain were observed between control and treatment birds fed the compound ( > 0.05). Follow up mechanistic analysis revealed that sub-inhibitory concentration of BR significantly reduced motility, attachment to and invasion of Caco-2 cells. In addition, the expression of genes coding for motility () and attachment () was down-regulated as compared to controls ( < 0.05). These results suggest that BR could potentially be used as a feed additive to reduce colonization in broilers.
是主要的食源性病原体之一，主要通过食用受污染的家禽产品导致人类严重肠胃炎。鸡是该病原体的储存宿主，病原体在盲肠定殖，从而在屠宰过程中导致胴体污染。减少该病原体在盲肠的定殖将直接转化为产品污染减少和人类感染风险降低。随着消费者对无抗生素鸡肉需求的增加，正在进行大量研究以发现能够有效控制该病原体在禽类中定殖的天然、安全且经济的抗菌剂。本研究调查了在饲料中添加一种植物酚类化合物β - 间苯二酚酸（BR）对减少肉鸡中该病原体定殖的效果。在两项独立的重复试验中，将一日龄雏鸡（科宝500；每组10只鸡）用饲料中添加0、0.25%、0.5%或1%的BR喂养14天（每组40只鸡）。在第7天用该病原体的四菌株混合物（约10⁸CFU/ml；每只鸡250μl）对鸡进行攻毒，并在第14天收集盲肠样本以计数盲肠内容物中存活的该病原体。此外，使用表型分析、细胞培养和实时定量PCR研究了BR对该病原体关键定殖因子（运动性、上皮细胞附着）的影响。在饲料中添加0.5%和1%的BR 14天分别使盲肠内容物中该病原体数量减少约2.5和1.7 Log CFU/g（P<0.05）。在喂食该化合物的对照鸡和处理鸡之间未观察到采食量和体重增加的显著差异（P>0.05）。后续的机制分析表明，亚抑制浓度的BR显著降低了该病原体的运动性、对Caco - 2细胞的附着和侵袭。此外，与对照相比，编码运动性（flhDC）和附着（fimA）的该病原体基因的表达下调（P<0.05）。这些结果表明，BR有可能用作饲料添加剂以减少肉鸡中该病原体的定殖。
