The hidden companion of non‐native fishes in north‐east Atlantic waters

A tropicalization phenomenon of ichthyofauna has been described in the last decades in Galicia (north‐eastern Atlantic), with increasing reports of tropical and subtropical fishes appearing northward this distribution range. A search for parasites was carried out in the digestive tract of two specimens first captured in Galician waters: the prickly puffer Ephippion guttifer (Tetraodontidae) and the African stripped grunt Parapristipoma octolineatum (Haemulidae). Examination of E. guttifer showed high intensity of nematodes, from three different genera: Cucullanus (Cucullanidae), Hysterothylacium (Raphidascaridae) and Anisakis (Anisakidae), with demonstrated pathogenicity to humans. Molecular identification allowed the identification of Anisakis pegreffii, already described in the area, and first reports for European waters of Cucullanus dodsworthi, Hysterothylacium reliquens and a new Hysterothylacium sp. P. octolineatum showed a far lower level of parasitization, with two Hysterothylacium larvae, genetically identified as Hysterothylacium deardorffoverstreetorum, also its first report in the eastern Atlantic. Thus, possible ecological impact of the occurrence of two non‐native individual fishes in a new area could be remarkably higher if we see this issue through the lens of the parasitological perspective, as far as only two individual fish can harbour more of one hundred nematode parasites belonging to different species, most of them also new species for that area.     

简单异尖线虫肌钙蛋白类过敏原基因的克隆表达及免疫特性分析

为研究简单异尖线虫肌钙蛋白类过敏原的免疫特性,本研究提取了线虫总RNA,逆转录合成cDNA,PCR扩增肌钙蛋白类过敏原(Anis1)基因,克隆入pMD18-T载体,测序正确后将anis1基因亚克隆入带有组氨酸标签的表达载体pET-30a,转入大肠杆菌BL21中,经异丙基硫代-β-D-半乳糖苷诱导,表达目的蛋白。通过Ni2+亲和层析柱对重组蛋白进行纯化,融合蛋白采用Western blotting分析。将纯化的Anis1重组蛋白免疫小鼠,分离血清,ELISA检测不同时期血清抗体效价。酶切和DNA测序结果显示重组质粒构建成功,并诱导出重组Anis1蛋白,重组蛋白经Western blotting分析证实为目的蛋白,纯化蛋白Anis1免疫小鼠后,与对照组相比,能产生较高的抗体水平。Western blotting分析显示,重组蛋白Anis1能被免疫血清识别,说明简单异尖线虫重组蛋白Anis1具有较好的免疫原性和免疫反应性。     

Collie eye anomaly in Collies in the Netherlands

Summary

The eyes of 160 Collies were examined for Collie Eye Anomaly, Progressive Retinal Atrophy, and any other eye abnormality present. The incidence of CEA in 160 Collies was 40.6 per cent.

There were no cases of PRA. Other abnormalities noted were distichiasis, persistent pupillary membranes, distinct remnants of the hyaloid artery, corneal dystrophy and unilateral cataracts.     

我国异尖线虫病研究进展

异尖线虫病呈世界性分布,已成为重要的食源性人兽共患寄生虫病,严重威胁人类的健康,是我国禁止入境的二类寄生虫病。综述了异尖线虫病的病原学、生活史、地理分布、发病机制和临床症状,重点概括了国内海鱼体内异尖属线虫的感染、种类分布和国内尚未出现病例报道的原因,进一步强调异尖线虫病的防控对中国水产养殖业乃至全世界的重要性,并对今后的研究前景进行展望,以期为防控异尖线虫病奠定基础。     

东海区黄鳍东方鲀寄生异尖线虫的鉴定及河鲀毒素检测

通过检查东海区283尾野生黄鳍东方鲀(Takifugu xanthopterus)样本,发现具有河鲀毒素的黄鳍东方鲀也受到线虫的感染。11月份黄鳍东方鲀体内异尖线虫感染情况最严重。通过形态学特征和线粒体DNA鉴定,黄鳍东方鲀组织内寄生的线虫为派氏异尖线虫(Anisakis pegreffii)。免疫组学分析发现异尖线虫体内含有河鲀毒素,进一步的高效液相色谱-质谱检测结果显示异尖线虫体内河鲀毒素含量为425 ng/g,这是首次发现寄生在东方鲀体内的线虫具有河鲀毒素。     

Possibility of anisakid larvae infection in farmed salmon

SUMMARY: Nematodes belonging to the family Anisakidae including Anisakis simplex and Pseudoterranova decipiens are known to cause anisakiasis when their live larvae are ingested by humans. We estimated the possibility of anisakid infection to salmonids, farmed in sea net-pens at Onagawa Bay, Miyagi, Japan, in 1992, 1998 and 1999, by direct examination of the edible muscle and examination of the contents of the alimentary canal. From direct examination of the muscle, no nematode was found in the 249 farmed coho salmon Oncorhynchus kisutch and 40 farmed rainbow trout Oncorhynchus mykiss . In contrast, third-stage larvae of Anisakis simplex were found in seven of 14 wild coho salmon caught in Russia and all the 40 wild chum salmon Oncorhynchus keta caught at Nemuro and Kesennuma in 1998. The stomach and intestines of 521 farmed coho salmon and 40 farmed rainbow trout were examined carefully for the existence of possible carrier organisms such as crustaceans, fish or squid. Such carrier organisms were not found in the stomach and intestines of farmed fish. Thus, we conclude that the possibility of anisakid infection is very low in farmed salmonids.     

The impact of carbofuran on acetylcholinesterase activity in Anisakis simplex larvae from Baltic herring

The aim of this study was to investigate the impact of carbofuran, a carbamate pesticide on the enzymatic activity of acetylcholinesterase (AChE) in the larvae of the herring nematode parasite Anisakis simplex. A. simplex larvae collected from herring were exposed to carbofuran in vivo at concentrations of 50, 100, 500 and 1000 μg/l, for 24, 48 and 72 h, at a temperature of 4 °C. Generalized Linear Models (GLM) were applied to analyze the relationship between AChE activity and carbofuran concentration, the time of exposure and the biological parameters of the host. The results indicate that A. simplex larvae have a high threshold of sensitivity to carbofuran. The average enzymatic activity was higher in parasites obtained from male hosts, when compared with female hosts. These data suggest that host sex-dependent biological processes may also influence AChE enzymatic activity in parasites.     

Geographical variations in infection by larval Anisakis simplex and Contracaecum osculatum (Nematoda, Anisakidae) in walleye pollock Theragra chalcogramma stocks off Hokkaido, Japan

ABSTRACT: Stocks of walleye pollock Theragra chalcogramma collected from: (i) the Sea of Japan (off Rebun Island and Kumaishi); (ii) the Pacific coast (off Shikabe and eastern Hokkaido); and (iii) Nemuro Strait off Hokkaido, northern Japan, were examined for anisakid nematodes during December 1999 to February 2000, and the prevalence and abundance of Anisakis simplex and Contracaecum osculatum larvae were compared among the various sampling sites for fish of the same size and age. Anisakis simplex was generally more abundant than C. osculatum . Infection by A. simplex varied between the aforementioned stocks of walleye pollock as well as within stocks, whereby fish from off Rebun Island and Nemuro Strait were infected the most, followed by those from off the Pacific coast and Kumaishi. Infection by C. osculatum differed between the host stocks, and C. osculatum was the most abundant among the fish from Nemuro Strait. The infection variations seemed to be due to differences in host growth rate, host feeding habit, and the distribution of marine mammal final hosts. The results indicate that these two larval nematodes are useful biological indicators for the population study of walleye pollock in Japanese waters.     

用POR和POR-RFLP方法检测和鉴定进口海鱼中的异尖线虫幼虫

应用PeR和PCR—RFLP方法对厦门口岸进口的各种海鱼中的异尖线虫幼虫进行检测鉴定。结果在带鱼、竹荚鱼、金线鱼、大眼鲷和白姑鱼等海鱼中发现了简单异尖线虫、典型异尖线虫、对盲囊线虫和针回线虫等4种异尖线虫。带鱼和竹荚鱼的异尖线虫感染率达100％,竹荚鱼异尖线虫感染强度最高,白姑鱼感染率和感染强度相对较低。少数海鱼同时感染2种以上异尖线虫,从带鱼中同时检出简单异尖线虫和针蛔线虫,从竹荚鱼中检出简单异尖线虫、对盲囊线虫和典型异尖线虫。内切酶实验结果表明,应用限制性内切酶UinfI有效鉴别上述4种异尖线虫。