A longitudinal study of the role of Dichelobacter nodosus and Fusobacterium necrophorum load in initiation and severity of footrot in sheep.
A longitudinal study of the role of Dichelobacter nodosus and Fusobacterium necrophorum load in initiation and severity of footrot in sheep.
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DOI：
10.1016/j.prevetmed.2014.03.004
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发表时间：
2014-07-01
影响因子：
2.6
通讯作者：
Wellington EM
中科院分区：
文献类型：
--
作者：
Witcomb LA;Green LE;Kaler J;Ul-Hassan A;Calvo-Bado LA;Medley GF;Grogono-Thomas R;Wellington EM
蹄疾是绵羊的一种传染性细菌性疾病，会导致跛行。病原菌为结节双歧杆菌。关于坏死梭杆菌在疾病发生中的作用还存在争议。本研究采用纵向观察研究的方法，结合对结节盾壳菌和坏斑镰刀菌细菌载量的定量聚合酶链式反应(QPCR)分析，阐明了每种细菌在疾病发生发展中的作用。对18只事先选定的绵羊的所有脚进行了为期五周的监测，以评估疾病的严重程度(健康、指间皮炎(ID)和严重蹄疾(SFR))和细菌负荷。使用多项式模型对这些数据进行分析。关键的未调整结果是，结节螺旋体在有ID的足部更频繁地被检测到，而坏死菌在SFR的足部更频繁地被检测到。在多项式模型中，ID与结节吸虫在观察周和发育前一周的log10负荷增加有关(OR=11.28(95%CI=11.08-1.53))(OR=111.20(95%CI=11.01-1.42))。坏死菌的log10载量2与ID的存在无关(OR=0.99(95%CI=0.96-1.02))。SFR与发病前一周结节螺旋体的log10负荷增加有关(OR=11.42(95%CI=11.02-1.96))，但与SFR发生后无关。一旦发病，SFR与坏死菌的log10载量2呈正相关(OR=111.06(95%CI=111.01~1.11))。总而言之，在ID和SFR发生前一周以及在ID发作期间，结节螺旋体负荷增加的风险增加。相反，坏疽杆菌负荷在发病前或发作期间与ID无关，只有在出现后才与SFR有关。这些结果有助于我们更好地理解Footrot的流行病学，并强调结节圆线虫的负荷在疾病的发生和发展中起主要作用，而坏疽杆菌负荷起次要作用。对更多的种群和气候进行进一步的研究将有助于证实这些发现。这项研究发现，在ID期间，结节螺旋体的负荷最高。这支持了以前的流行病学研究结果，这表明控制ID是预防ID和SFR新病例的最有效的管理策略。
Footrot is an infectious bacterial disease of sheep that causes lameness. The causal agent is Dichelobacter nodosus. There is debate regarding the role of Fusobacterium necrophorum in disease initiation. This research used an observational longitudinal study of footrot, together with quantitative PCR (qPCR) of bacterial load of D. nodosus and F. necrophorum, to elucidate the roles of each species in the development of disease. All feet of 18 a priori selected sheep were monitored for five weeks assessing disease severity (healthy, interdigital dermatitis (ID) and severe footrot (SFR)) and bacterial load. A multinomial model was used to analyse these data. Key unadjusted results were that D. nodosus was detected more frequently on feet with ID, whereas F. necrophorum was detected more frequently on feet with SFR. In the multinomial model, ID was associated with increasing log10 load of D. nodosus the week of observation (OR = 1.28 (95% CI = 1.08–1.53)) and the week prior to development of ID (OR = 1.20 (95% CI = 1.01–1.42). There was no association between log10 load2 of F. necrophorum and presence of ID (OR = 0.99 (95% CI = 0.96–1.02))). SFR was associated with increasing log10 load of D. nodosus the week before disease onset (OR = 1.42 (95% CI = 1.02–1.96)) but not once SFR had occurred. SFR was positively associated with log10 load2 of F. necrophorum once disease was present (OR = 1.06 (95% CI = 1.01–1.11)). In summary, there was an increased risk of increasing D. nodosus load the week prior to development of ID and SFR and during an episode of ID. In contrast, F. necrophorum load was not associated with ID before or during an episode, and was only associated with SFR once present. These results contribute to our understanding of the epidemiology of footrot and highlight that D. nodosus load plays the primary role in disease initiation and progression, with F. necrophorum load playing a secondary role. Further studies in more flocks and climates would be useful to confirm these findings. This study identifies that D. nodosus load is highest during ID. This supports previous epidemiological findings, which demonstrate that controlling ID is the most effective management strategy to prevent new cases of ID and SFR.
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影响因子：
3.3
作者：
Calvo-Bado, Leo A.;Green, Laura E.;Wellington, Elizabeth M. H.
通讯作者：
Wellington, Elizabeth M. H.
影响因子：
3.3
作者：
Moore, LJ;Wassink, GJ;Grogono-Thomas, R
通讯作者：
Grogono-Thomas, R
影响因子：
3.7
作者：
Pontiroli A;Travis ER;Sweeney FP;Porter D;Gaze WH;Mason S;Hibberd V;Holden J;Courtenay O;Wellington EM
通讯作者：
Wellington EM
影响因子：
2.3
作者：
Bennett, Grant;Hickford, Jon;Zhou, Huitong
通讯作者：
Zhou, Huitong
影响因子：
0.8
作者：
EGERTON, JR;ROBERTS, DS
通讯作者：
ROBERTS, DS