西伯利亚鲟桑葚心病理组织学和病因的初步研究

为了对心脏囊肿状病变的西伯利亚鲟进行病理组织学观察和病因初步探讨,使用病理组织学和电镜观察技术,对患病西伯利亚鲟各器官进行组织病理学观察。结果表明,患病西伯利亚鲟心脏表面可观察到米粒大、息肉状、紫褐色的囊状肿物,似桑葚状,心外膜上皮细胞和结缔组织明显增生,形成囊肿。组织病变为心外膜囊肿,呈动态发展过程,主要表现为囊肿上皮由扁平变为立方上皮;囊肿壁逐渐增厚与分化,使囊腔不断增多变大,腔内有大量未分化的圆球形、梭形等不同成熟度的血细胞,形成血管组织,并浸润着大量游离或团状分布细胞,整个病变类似一种肿瘤型的恶性增生,心肌细胞肿胀,断裂,溶解,坏死;肝细胞脂肪变性并浸润炎性细胞;肾间质和脾脏淋巴细胞增多。鳃小片之间观察到大量细菌侵袭上皮细胞;鳃小片上皮细胞严重肿胀增生。电子显微镜观察到心脏、肝脏、脾脏和肾脏中有大量细菌;该病可能与微量元素有关,所观察到的细菌不是直接病因。本实验对西伯利亚鲟桑葚心病的组织病理变化进行了较为系统的研究,为进一步查明病因、临床诊断防治和致病机理等相关研究提供基础资料。     

Edwardsiellosis in farmed turbot,Scophthalmus maximus (L.), associated with an unusual variant of Edwardsiella tarda: a clinical,aetiological and histopathological study

During 2005 and 2010, a survey of edwardsiellosis on eight turbot, Scophthalmus maximus (L.), farms was conducted in China. This report presents the detailed results of the study on this disease. Diseased turbot displayed two distinct types of gross signs: black discoloration of the dorsal skin on the posterior portion of the body; and red cutaneous foci on the ventral side. Internally, the most pronounced clinical signs in all fish examined were enlarged kidneys. The causal agent of the disease was finally proved to be one species of bacterium that was identified as Edwardsiella tarda by physiological and biochemical tests, API 32E and 16S ribosomal RNA sequence analysis. It is noteworthy that unlike the commonly described E. tarda strains, the isolates in this study were non‐motile strains without flagella. A histopathological study revealed that E. tarda infection was systemic in turbot and that kidney showed the most significant pathological changes, including acute focal necrosis, an influx of macrophages and formation of granuloma. The most common histopathological characteristics of this disease are the proliferation of macrophage in various organs and formation of granuloma. In addition, this article also gave background information on the disease and presented the results of virulence tests with the E. tarda strain identified in this study.     

大鼠子宫内膜炎模型的建立及其动态病理学观察

【目的】建立大鼠子宫内膜炎模型,为子宫内膜炎的发病机理及其预防治疗研究提供合适的动物病理模型。【方法】将30只清洁级雌性大鼠随机分为感染组(22只)和对照组(8只),采用手术法给大鼠子宫腔内感染致病性大肠埃希菌、金黄色葡萄球菌、无乳链球菌(菌液体积比为2∶1∶1)的混合菌液,对照组大鼠未感染致病菌的混合菌液。分别于感染后第3,6,9,12天剖杀大鼠,检测其大体剖检病变和组织病理学变化,计算子宫指数,并对子宫内容物病原菌进行分离鉴定。【结果】感染后3~12 d,感染组大鼠子宫指数均较对照组大鼠极显著增加(P0.01),感染大鼠子宫出现急性卡他性炎症(感染后第3天和第6天)、化脓性炎症(感染后第9天)和慢性增生性炎症(感染后第12天);感染前期可见子宫内膜上皮细胞脱落,黏膜层水肿、充血、出血,炎症细胞浸润;感染后期可见肌层增厚等病变。【结论】采用手术法成功建立了大鼠子宫内膜炎模型,且感染后第3天为造模成功的最佳时间。     

香蕉枯萎病菌及其粗毒素对香蕉的致病性比较

从8种培养液中筛选出能诱导香蕉枯萎病菌4号小种(Fusarium oxysporum f.sp.cubense race4)FOCAAA315菌株高产毒素的改良CzapekB培养液,FOCAAA315菌株在该培养液中培养第15d,镰刀菌酸(FA)产量高达669.2mg/L,蔗糖为诱导产毒的最佳碳源。采用伤根浸渍法接种,测定枯萎病菌和病菌发酵粗毒素对香蕉组培苗的致病性。结果表明,粗毒素接种可诱发与病原菌类似的病害症状。受侵染的植物组织在细胞水平上发生一系列形态结构和生理生化代谢的病理变化,包括细胞壁消解、侵填体堵塞气腔、粘胶质减少、淀粉量减少、细胞木质化和黄褐色胶状物堵塞导管等。香蕉枯萎病菌的粗毒素是重要的致病化学物质;利用病菌孢子悬浮液在香蕉苗期接种,可以作为室内快速鉴定香蕉品种抗病性的方法。     

一例犬恶性黑色素瘤的临床诊治

犬黑色素瘤比较常见,以皮肤色素深的老年犬多发。通过对1例患恶性黑色素瘤松狮犬的跟踪观察和治疗,就其临床症状、病理诊断做了较为详细的研究,以期为该病在小动物临床中的诊疗提供依据。     

辽宁一例凡纳滨对虾大规模死亡的病原研究

为对辽宁省盘锦地区2014年出现的大规模死亡凡纳滨对虾Litopenaeus vannamei展开病原研究,对死虾进行了白斑综合征病毒(WSSV)、桃拉病毒(TSV)、传染性皮下及造血组织坏死病病毒(IHHNV)和嗜水气单胞菌Aeromonas hydrophila的分析鉴定,提取病虾鳃组织DNA/RNA后,以特异性引物进行WSSV、TSV和IHHNV病毒检测,通过16S r DNA测序及嗜水气单胞菌特异性引物和气溶素基因的双重PCR对分离菌株QD1进行分类鉴定,并对病虾的鳃、胃、肝胰腺和附肢进行了组织病理切片观察。结果表明:患病对虾WSSV和TSV检测呈阳性;菌株QD1为嗜水气单胞菌,其人工回归感染试验结果显示,分离菌株能使健康凡纳滨对虾致病死亡;组织病理学观察显示,病虾鳃及胃组织出现大量WSSV特征性的病变核,肝胰腺上皮细胞出现严重萎缩,肝胰腺管腔变大,部分肝细胞坏死,肝胰腺管之间结缔组织中血细胞明显增多。研究表明,此次凡纳滨对虾大量死亡为WSSV和TSV两种病毒与嗜水气单胞菌混合感染所致。     

自然感染鲤疱疹病毒Ⅱ的病毒载量研究

通过建立靶向于鲤疱疹病毒Ⅱ(Cyprinid herpesvirus 2,Cy HV-2)胸苷激酶基因(TK基因)的荧光定量PCR法,分别检测了自然感染Cy HV-2的金鱼、鲫样品,并结合人工感染试验,分析了脾和肾组织内Cy HV-2的载量及其引发的组织病理变化。结果表明,自然感染Cy HV-2的金鱼和鲫的病毒拷贝数范围为102~105,人工感染Cy HV-2的异育银鲫在感染后第五天脾和肾组织内病毒的拷贝数高达1010。人工感染条件下鱼体呈现系统性病理损伤,自然感染状态下鱼体脾和肾的病理变化分别表现为细胞嗜性的转变和炎症。     

MC-LR急性胁迫对草鱼脾脏、头肾显微结构及BAFF和APRIL基因表达的影响

为探讨微囊藻毒素-LR(microcystin-LR,MC-LR)对鱼类的免疫毒性,采用急性毒性实验方法,分别对草鱼经腹腔注射不同剂量的MC-LR并于24、48、72 h和96 h后取免疫器官脾脏和头肾进行组织显微结构分析。结果显示,随着MC-LR剂量的增加和时间的延长,脾脏组织呈现出细胞空泡化并伴随着黑色素巨噬细胞先增多后减少的现象,尤其在75μg MC-LR·kg~(-1)BW和100μg MC-LR·kg~(-1)BW剂量组染毒48 h后,黑色素巨噬细胞中心体积显著增大;头肾组织显微结构变化主要表现为血窦、血管扩张,在75μg MC-LR·kg~(-1)BW和100μg MC-LR·kg~(-1)BW剂量组中的草鱼染毒72 h和96 h后,淋巴组织松散、排列混乱,淋巴细胞空泡化甚至细胞裂解。此外,采用荧光定量PCR分析了草鱼经不同剂量MC-LR处理96 h后脾脏和头肾中BAFF和APRIL基因表达的变化。结果显示BAFF和APRIL的表达均被不同程度地抑制,其中脾脏组织中BAFF基因在75μg MC-LR·kg~(-1)BW剂量组中被显著抑制(P0.05),头肾组织BAFF基因在75、100μg MC-LR·kg~(-1)BW剂量组中均被显著抑制(P0.05),而APRIL除了在25μg MC-LR·kg~(-1)BW剂量组的脾脏组织中表达下调不显著外,在其他处理组均被显著抑制(P0.05)。以上研究结果表明,MC-LR可导致草鱼免疫器官一系列的病理变化,并有时间和剂量效应,此外,MC-LR还可抑制B淋巴细胞分裂相关基因的表达。     

Long‐term epidemiological survey of Kudoa thyrsites (Myxozoa) in Atlantic salmon (Salmo salar L.) from commercial aquaculture farms

Kudoa thyrsites (Myxozoa) encysts within myocytes of a variety of fishes. While infected fish appear unharmed, parasite‐derived enzymes degrade the flesh post‐mortem. In regions of British Columbia (BC), Canada, up to 4–7% of fillets can be affected, thus having economic consequences and impacting the competitiveness of BC's farms. K. thyrsites was monitored in two farms having high (HP) or low (LP) historical infection prevalence. At each farm, 30 fish were sampled monthly for blood and muscle during the first year followed by nine samplings during year two. Prevalence and intensity were measured by PCR and histology of muscle samples. In parallel, fillet tests were used to quantify myoliquefaction. Infections were detected by PCR after 355 and 509 degree days at LP and HP farms, respectively. Prevalence reached 100% at the HP farm by 2265 degree days and declined during the second year, whereas it plateaued near 50% at the LP farm. Infection intensities decreased after 1 year at both farms. Blood was PCR‐positive at both farms between 778 and 1113 degree days and again after 2000 degree days. This is the first monitoring project in a production environment and compares data between farms with different prevalence.