Identification of Bacillus strains for biological control of catfish pathogens.
Identification of Bacillus strains for biological control of catfish pathogens.
复制标题
用于鲶鱼病原体生物防治的芽孢杆菌菌株的鉴定。
DOI：
10.1371/journal.pone.0045793
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Liles MR
中科院分区：
文献类型：
--
作者：
Ran C;Carrias A;Williams MA;Capps N;Dan BC;Newton JC;Kloepper JW;Ooi EL;Browdy CL;Terhune JS;Liles MR
从土壤和通道鲶鱼肠中分离的芽孢杆菌菌株分别对鲶鱼肠败血症（ESC）和运动性气单胞菌（MAS）的病原爱德华氏菌（Edwardsiella ictaluri）和嗜水气单胞菌（Aeromonas ophilia）进行拮抗。筛选21株菌株，测定其对其他水生病原菌的拮抗活性。排名前21位的菌株对多种水生细菌病原体均表现出拮抗活性，包括迟发爱德华氏菌、牛链球菌、拉克氏耶尔森氏菌、柱状黄杆菌和/或铁腐卵菌。用添加芽孢杆菌的饲料饲喂7 d，正常饲料饲喂3 d，测定21株芽孢杆菌在鲶鱼肠道组织中的存活率，以芽孢杆菌CFU/g计算。将5株具有良好抗菌活性和肠道存活能力的芽孢杆菌以孢子形式加入饲料中，以8×107 CFU/g的剂量喂给通道鲶鱼14天，然后重复攻毒。两种枯草芽孢杆菌菌株对降低鲶鱼死亡率有显著作用（P<0.05）。在越南用五种芽孢杆菌中的四种菌株进行的类似挑战实验也显示出对条纹鲶鱼的伊氏芽孢杆菌有保护作用。研究人员还从菌株是否含有质粒或对临床重要抗生素表现出耐药性的角度，对体内生物控制最强的4株菌株的安全性进行了研究。本研究鉴定的芽孢杆菌菌株作为鲶鱼养殖的益生菌饲料添加剂具有良好的疾病防治潜力。
Bacillus strains isolated from soil or channel catfish intestine were screened for their antagonism against Edwardsiella ictaluri and Aeromonas hydrophila, the causative agents of enteric septicemia of catfish (ESC) and motile aeromonad septicaemia (MAS), respectively. Twenty one strains were selected and their antagonistic activity against other aquatic pathogens was also tested. Each of the top 21 strains expressed antagonistic activity against multiple aquatic bacterial pathogens including Edwardsiella tarda, Streptococcus iniae, Yersinia ruckeri, Flavobacterium columnare, and/or the oomycete Saprolegnia ferax. Survival of the 21 Bacillus strains in the intestine of catfish was determined as Bacillus CFU/g of intestinal tissue of catfish after feeding Bacillus spore-supplemented feed for seven days followed by normal feed for three days. Five Bacillus strains that showed good antimicrobial activity and intestinal survival were incorporated into feed in spore form at a dose of 8×107 CFU/g and fed to channel catfish for 14 days before they were challenged by E. ictaluri in replicate. Two Bacillus subtilis strains conferred significant benefit in reducing catfish mortality (P<0.05). A similar challenge experiment conducted in Vietnam with four of the five Bacillus strains also showed protective effects against E. ictaluri in striped catfish. Safety of the four strains exhibiting the strongest biological control in vivo was also investigated in terms of whether the strains contain plasmids or express resistance to clinically important antibiotics. The Bacillus strains identified from this study have good potential to mediate disease control as probiotic feed additives for catfish aquaculture.