Petrie-Hanson L, Romano C L, Mackey R B, Khosravi P, Hohn C M, Boyle C R
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Post Office Box 6100, Mississippi State, Mississippi 39762, USA.
J Aquat Anim Health. 2007 Sep;19(3):151-8. doi: 10.1577/H06-026.1.
Zebrafish (also known as zebra danio) Danio rerio were injected intramuscularly with Edwardsiella ictaluri at doses of 6 x 10(3), 6 x 10(4), or 6 x 10(5) colony-forming units per gram (CFU/g) or sterile phosphate-buffered saline (sham) or were not injected. Mortality occurred from 2 to 5 d postinjection (dpi) at rates of 0, 76.6, and 81.3% for the low, medium, and high doses, respectively, and E. ictaluri was isolated from dead fish. Survivors were sampled at 10 dpi and E. ictaluri was not isolated. Sham-injected and noninjected controls did not suffer mortality. Histopathology trials were performed in which zebrafish were injected with 1 x 10(4) CFU/g or sham-injected and sampled at 12, 24, 48, 72, and 96 h postinjection for histological interpretation. Collectively, these zebrafish demonstrated increasing severity of splenic, hepatic, cardiac, and renal interstitial necrosis over time. To evaluate the progression of chronic infection, zebrafish were injected with 1 x 10(2) CFU/g and held for 1 month postinjection. Beginning at 12 dpi and continuing for an additional 2 weeks, zebrafish demonstrated abnormal spiraling and circling swimming behaviors. Histopathology demonstrated necrotizing encephalitis. In immersion trials, zebrafish were exposed to low, medium, and high doses (averaging 1.16 x 10(5), 1.16 x 10(6), and 1.16 x 10(7) CFU/mL of tank water) of E. ictaluri for 2 h. Mortality occurred from 5 to 9 d postexposure at rates of 0, 3.3, and 13.3% for the low, medium, and high doses, respectively; E. ictaluri was isolated from dead fish. Channel catfish Ictalurus punctatus exposed to the medium doses suffered 100% mortality, and E. ictaluri was isolated from these fish. This study demonstrates the potential use of zebrafish as a model for E. ictaluri pathogenesis.
将每克6×10³、6×10⁴或6×10⁵菌落形成单位（CFU/g）的爱德华氏菌（Edwardsiella ictaluri）或无菌磷酸盐缓冲盐水（假注射）肌肉注射到斑马鱼（也称为斑马丹鱼，Danio rerio）体内，或不进行注射。注射后2至5天出现死亡，低剂量、中剂量和高剂量的死亡率分别为0%、76.6%和81.3%，并且从死鱼中分离出了爱德华氏菌。在注射后10天对存活的斑马鱼进行采样，未分离出爱德华氏菌。假注射和未注射的对照组未出现死亡。进行了组织病理学试验，将斑马鱼注射1×10⁴CFU/g或进行假注射，并在注射后12、24、48、72和96小时进行采样以进行组织学分析。总体而言，这些斑马鱼随着时间推移脾脏、肝脏、心脏和肾脏间质坏死的严重程度不断增加。为了评估慢性感染的进展，将斑马鱼注射1×10²CFU/g并在注射后饲养1个月。从注射后12天开始并持续另外2周，斑马鱼表现出异常的螺旋式和圆周式游泳行为。组织病理学显示为坏死性脑炎。在浸泡试验中，将斑马鱼暴露于低、中、高剂量（平均每毫升鱼缸水1.16×10⁵、1.16×10⁶和1.16×10⁷CFU）的爱德华氏菌中2小时。暴露后5至9天出现死亡，低剂量、中剂量和高剂量的死亡率分别为0%、3.3%和13.3%；从死鱼中分离出了爱德华氏菌。暴露于中剂量的斑点叉尾鮰（Ictalurus punctatus）死亡率为100%，并且从这些鱼中分离出了爱德华氏菌。本研究证明了斑马鱼作为爱德华氏菌致病机制模型的潜在用途。
