NetF-positive Clostridium perfringens in neonatal foal necrotising enteritis in Kentucky
NetF-positive Clostridium perfringens in neonatal foal necrotising enteritis in Kentucky
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DOI：
10.1136/vr.103606
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发表时间：
2016-02-27
影响因子：
2.2
通讯作者：
Prescott, J. F.
中科院分区：
文献类型：
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作者：
Gohari, I. Mehdizadeh;Parreira, V. R.;Prescott, J. F.
A型产气荚膜梭菌与肯塔基州1 - 14日龄马驹的坏死性肠炎有关（Donahue and Williams 2002, Timoney and others 2005），但该疾病的发病机制尚不清楚，部分原因是受感染的马驹很少死亡，因此可获得的死后样本很少。一种利用含α毒素（CPA）、β2毒素（CPB2）和肠毒素（CPE）基因的产气荚膜梭菌a型菌株（UK MF 05/00）的自体细菌-类毒素疫苗，进一步富集了重组CPB2毒素，用于对有马驹腹泻史的肯塔基州种猪场的母马免疫（Timoney等，2005年）。最近，一种新的孔隙形成毒素NetF与马驹坏死性肠炎和犬出血性胃肠炎密切相关（Mehdizadeh Gohari等，2015年）。在这里，作者首次报道了在肯塔基州肠炎和小肠结肠炎马驹中发现NetF阳性的A型产气荚膜杆菌，以及在肯塔基州用于对马进行免疫的细菌-类毒素疫苗（UK MF 05/00）中发现NetF （Timoney等人，2005年）。从2000年至2011年肯塔基州患有严重肠炎的马驹中分离出包括英国MF 05/00在内的产气荚膜梭菌分离株（表1），通过多重PCR筛选netF和cpe的存在，cpe与netF密切相关（Mehdizadeh Gohari等，2015年）。这些分离株自最初培养以来一直冷冻保存。在相同的多重PCR中，通过cpa基因的存在证实了它们是产气荚膜荚膜梭菌。使用InstaGene Matrix （Bio-Rad Laboratories, Mississauga, Canada）按照制造商的方案提取DNA。多重PCR使用细胞毒性基因cpa， cpe和netF的引物进行扩增和其他条件描述(Mehdizadeh Gohari等2015；Finley， A., Medizadeh Gohari， I., Parreira， VR, Abrahams， M., Staempfli，
TYPE A Clostridium perfringens has been associated with necrotising enteritis in 1–14-day-old foals in Kentucky (Donahue and Williams 2002, Timoney and others 2005) but the pathogenesis of the disease is not well understood, in part because few affected foals die and thus the availability of postmortem samples is rare. An autogenous bacterin-toxoid vaccine utilising a C. perfringens Type A strain (UK MF 05/00) that carries genes for the α toxin (CPA), β2 toxin (CPB2) and enterotoxin (CPE), further enriched with recombinant CPB2 toxin, is used to immunise mares on Kentucky breeding farms with histories of foal diarrhoea (Timoney and others 2005). Recently, a novel pore-forming toxin NetF has been strongly associated with foal necrotising enteritis and canine haemorrhagic gastroenteritis (Mehdizadeh Gohari and others 2015). Here, the authors report for the first time the identification of netF-positive type A C. perfringens in foals with enteritis and enterocolitis in Kentucky and the presence of NetF in the bacterin-toxoid vaccine (UK MF 05/00) used to immunise mares in Kentucky (Timoney and others 2005).Isolates of C. perfringens including UK MF 05/00 from foals in Kentucky from 2000 to 2011, with severe enteritis (Table 1), were screened by multiplex PCR for the presence of netF and cpe, a gene with which netF is strongly linked (Mehdizadeh Gohari and others 2015). These isolates had been stored frozen since initial culture. Their identity as C. perfringens was confirmed in the same multiplex PCR by the presence of the cpa gene. DNA was extracted using InstaGene Matrix (Bio-Rad Laboratories, Mississauga, Canada) according to the manufacturer’s protocol. Multiplex PCR used primers for the cytotoxic genes cpa, cpe and netF, for amplification and other conditions as described (Mehdizadeh Gohari and others 2015; Finley, A., Medizadeh Gohari, I., Parreira, VR, Abrahams, M., Staempfli,