浙江省牛羊体内五种巨盘吸虫包括两个新种记述

1963～1984年在本省牛羊体内发现五种巨盘属吸虫,泰国巨盘吸虫发现于自云南引进的水牛胆管内,其它四种均发现于本省牛羊真胃内,腹吸盘巨大,其直径与体长之比均在1:2.1～2.376之间,其中两种系未见记载的虫种,定名为南湖巨盘吸虫(Gigantocotyle nanhuense)和温州巨盘吸虫(G.wenzhouense)。前者以生殖孔开口于口吸盘边缘和睾丸呈三叶草样或十字花样为其主要特征,可与扁形巨盘吸虫(G.explanatum)和孪生巨盘吸虫(G.fraternum)区别。后者以睾丸较小,胆管粗大,肠叉成锐角,子宫内虫卵甚少等为其主要特征,可与其它种巨盘吸虫相区别。     

水牛体内发现菲策属吸虫一新种

1981年在浙江象山县水牛体内发现一种新的菲策属吸虫,体型粗短,长度小等,体长8.0～11.9毫米,宽4～5毫米,虫体中部两侧近平行;肠支扭曲,盲端仅达虫体中部,睾丸巨大,略带前后倾斜排列,与最近似种泰国菲策吸虫的区别在于后者外观呈瓜子形,肠支直而无扭曲,睾丸小而前后排列,卵巢呈球形。作者定名为水牛菲策吸虫(Fischoederius bubalis n.sp.)     

家鸭体内棘口科吸虫一新种杭州棘口吸虫(Echinostoma hangzhouensis nov.sp.)

1980年在杭州家鸭体内发现一种新的棘口科吸虫,主要特征为头冠上有31枚头棘,其中背棘21枚分上下两列交错排列,大小相等;每边角棘各5枚,虫体狭长,外形呈中间窄两端宽,虫体宽长比例为1:21～26,定名为杭州棘口吸虫(Echinostoma hangzhouensis nov.sp)。本种与豆雁棘口吸虫(E.anseris Yamaguti,1939)的主要区别在于后者每边角棘为3枚,虫体外形呈中间而两端窄,宽长比例为1:8～9。与狭窄棘道吸虫(Echinodollfusia stenon,Dollfus,1950)的主要区别则在于其头棘43枚,其中背棘35枚,每边角棘4枚,两列头棘大小不等。     

丙硫咪唑对鸭自然感染环肠科吸虫的驱除试验

环肠科(Cyclocoelidae Kossack,1991)吸虫常寄生于家鸭呼吸系统,危害严重。嗜气管吸虫(Tracheophilus spp)寄生于鸭的气管、支气管,平体属吸虫(Hyptiasmus spp)和噬眼属吸虫(Ophthalmaphagus spp)则多寄生在鸭的鼻腔、鼻泪管和眶下窦(Sinus infraorbitalis)等处,由于虫体的机械刺激和分泌的毒素的影响,导致鸭营养不良、消瘦、羽毛失去光泽、呼吸困难、摇头、鸣叫痛苦、眼、鼻分泌物增多或出现脓性分泌物,以及眼失明相行走困难,甚至因虫体阻塞呼吸道发生窒息死亡。国内贵州、浙江等地报道嗜气管吸虫病流行导致鸭群出现“软脚瘟”以及呼吸困难和皮下气肿。 我省鸭感染环肠科吸虫比较严重,据省畜牧兽医研究所的省家鸭寄生虫的调查资料,环肠科吸虫的感染率为2～66%,感染强度1～61。种类有舟形嗜气管吸虫、谢氏平体吸虫、四川平体吸虫和成都平体吸虫两新种,马氏噬眼吸虫和鼻居噬眼吸虫。本次试验是我们进行隐孢子虫病流行病调查时发现一群麻鸭患严重的环肠吸虫感染,故进行本次试验。现报告于下:     

反刍动物三类吸虫病的诊断和防治

反刍动物三类吸虫病主要指:大拟片形吸虫也称大肝片吸虫;支双腔吸虫也称矛形双腔吸虫或小肝片吸虫;感染反刍动物的前后盘吸虫有许多种,如端盘吸虫、瘤胃吸虫和圆锥吸虫等。1反刍动物大拟片形吸虫病1.1虫体和感染大拟片形吸虫(大肝片吸虫),长100mm,厚2~4.5mm,宽11~26mm,椭圆形。其与肝片形吸虫的区别是缺少前面的圆锥突起。大拟片形吸虫常感染家畜和野生动物,鹿是其最主要的宿主。     

一例鸭舟形嗜气管吸虫诊断与治疗

环肠科吸虫寄生于鸟禽类的体腔、气囊、鼻腔和气管内,国内发现于家禽的种类分隶属与7个属中,其中以嗜气管属(Tracheophilus)的舟形嗜气管吸虫(T.cymbim)较为常见,在我国多个省市均有报道.     

有关水牛感染大片吸虫几点值得注意的问题

片形吸虫(Fasciola spp.)是一类寄生于反刍动物(水牛、奶牛和羊等)肝脏胆管的寄生蠕虫.片形吸虫有两个种(图1),分别为肝片吸虫(F.hepatica,分布于中国北方、欧洲等温带地区)和大片吸虫(F.gigantica,分布于中国南方、南亚等热带、亚热带地区).在我区,感染水牛的片形吸虫是大片吸虫,同时奶牛和山羊也常被这一寄生虫感染.     

RAPD与形态学对片形吸虫种类鉴别的比较研究

通过形态学特征观察与随机扩增多态DNA（RAPD）技术，对国内外8株片形吸虫（Fasciola)作比较鉴别。形态典型的6株肝片形吸虫（F.hepatica)和1株大片形吸虫（F.gigantica)两种方法结果。南京的1株不典型虫种（F.sp)，其形态特征类似日本中间种／印度片形吸虫（F.indica),RAPD检测则与大片形吸虫聚类，差异仅0．255，亲缘于大片形吸虫，是一株形态不典型的大片形吸虫。比较表明，形态学方法能简单易行正确地判定典型片形吸虫，但难以识别中间种或亲缘种；RAPD技术则从分子遗传变异水平上鉴别虫种，有利于对中间种或亲缘种的识别及新种的发现，两者具有相互不可替代的相辅相成作用。     

江西家鸭肠内印度光隙吸虫(Psilochasmus indicus Gupta)形态结构初报

常规实验室吸虫染色方法制作印度光隙吸虫标本,置显微镜下观察虫体外形、内部结构,测微尺测量虫体及各器官结构大小,用数码相机显微照相。结果表明,成虫腹吸盘大,有非常强的肌肉结构,明显突出体外一侧,使体前段往背部弯曲,纵轴两侧不对称,体后端于睾丸之后渐变尖,尾部稍长尖,口吸盘远小于腹吸盘。两睾丸椭圆形略有缺刻,雄茎囊大而长较为明显;卵巢长椭圆形,受精囊不明显,泡状卵黄腺分布虫体肠支外侧,起于腹吸盘下延伸至睾丸后;生殖孔不在叉肠下而在腹吸盘前方较远距离处。     

华支睾吸虫成虫cDNA表达文库的构建与筛选

为了获得华支睾吸虫成虫期强反应原性抗原基因,首先利用λZAP栽体构建华支睾吸虫成虫cDNA表达文库:即从我国东北疫区(镇赉县)家犬胆管内分离收集华支睾吸虫成虫,采用Trizol Reagent提取其总RNA,Oligo(dT)纤维素柱纯化mRNA,反转录合成第1链cDNA及第2链cDNA,用CHROMA SPIN-400柱离心层析纯化后,与栽体λZAP Express连接,体外包装后成功获得我国东北疫区华支睾吸虫成虫cDNA表达文库.文库容量为1.5×106pfu,重组率为99%,插入片段长度在0.4～2.0 kb之阀,扩增文库的滴度为1.5×1010pfu/mL.然后利用免疫学方法对该cDNA表达文库进行筛选:以自然感染华支睾吸虫的人血清为抗体探针,从2.0×105个重组噬菌体筛选强反应原性抗原基因,对筛选出的强反应原性克隆进行测序,利用相关分子生物学软件进行序列分析.共获得41个阳性克隆,测序结果分析表明,这些cDNAs根据其编码的蛋白可分为以下几种,即与来自华支睾吸虫的甘氨酸-2、脯氨酸-2及Cs44抗原高同源的基因及分别与来自Nematostella vectensis的未知蛋白、转录延伸因子及果蝇CG3446基因编码蛋白较低同源性的基因.本研究结果为进一步对华支睾吸虫抗原的生物学特性研究及应用奠定了理论基础和实验依据.     

Absence of hypobiosis in abomasal nematodes of sheep and goats in Egypt

A total of 96 abomasa from sheep and goats at the Zagazig abattoir, Sharkia Province, Egypt, were examined, during the four climatic seasons from April 1986 to March 1987, for the presence of adult and larval nematodes. Adults of Trichostrongylus axei were most numerous followed by adult Haemonchus contortus. Adult Ostertagia sp. and Parabronema skrjabini were less prevalent. There was no significant difference between sheep and goats in infection rates, but worm burdens of the nematodes other than Ostertagia sp. were significantly higher (P less than 0.05) in sheep than in goats. The animals were uniformly infected with these parasites throughout the year as there were no significant differences in the incidence or intensity of infections between the four seasons. The numbers of larvae recovered from the wall of the abomasa were small in relation to the total adult worm population throughout the year with a slight increase during the summer. Hypobiosis, therefore, seems not to be important in the life cycle of abomasal nematodes of sheep and goats in Sharkia Province, Egypt.     

Afrotropical Culicoides: C (Avaritia) miombo sp. nov., a widespread species closely allied to C. (A.) imicola Kieffer, 1913 (Diptera: Ceratopogonidae)

Culicoides (Avaritia) miombo sp. nov. is described and illustrated from both sexes collected in northern Malawi. Two references in the literature have previously referred to this new species as either C. brosseti Vattier & Adam or C. imicola Kieffer. A further 4 references are discussed that most likely deal with C. miombo sp. nov. and not C. brosseti. C. miombo sp. nov. is apparently widespread in subtropical and tropical Africa and is now recorded from Zimbabwe, Botswana, South Africa, Nigeria and the Ivory Coast. There are also probable records from Angola, Burkina Faso, Zambia and eastern Madagascar. On the African mainland, both north and south of the equator, the pattern of distribution of C. miombo sp. nov. correlates strongly with that of drier Guineo-Congolian rainforest, and Sudanian and Zambezian woodlands, the latter known as miombo in southern Africa. These phytochoria and associated biota are sensitive to frost and experience relatively high temperatures and rainfall-3 factors that appear to limit the distribution of C. miombo sp. nov. to north of the 20-22 degrees C mean annual temperature isotherms in southern Africa. The new species is a member of the Imicola group which consists of 6 species confined to the Afrotropical (including Madagascar), Oriental and eastern Palaearctic regions. One species has in historic times spread to Australia. The worldwide distribution of each species is briefly discussed. It is suggested that the Imicola and Orientalis groups are separate lineages within the subgenus Avaritia. Culicoides miombo sp. nov. is compared with its closest African congeners C. imicola, C. pseudopallidipennis Clastrier and C. bolitinos Meiswinkel; 15 character states are used to separate C. miombo sp. nov. and C. imicola. The female antennal and palpal measurements of C. miombo sp. nov. are subjected to statistical analysis to highlight their taxonomic usefulness. The larval habitat of C. miombo sp. nov. is unknown.     

The influence of physical and environmental variables on the in vitro attachment of Salmonella typhimurium to the ceca of chickens

This investigation was designed to study the effect of exposure time, pH, age of bird, and native intestinal microflora on the in vitro attachment of Salmonella typhimurium to the ceca of chickens. Ceca were surgically removed from chickens immediately after euthanasia, and the interiors were exposed to S. typhimurium as intact ceca with contents, intact ceca rinsed free of contents, or inverted rinsed ceca. Attachment of S. typhimurium was slightly higher in washed than in unwashed ceca. Neither pH nor age of chicks affected attachment of the organism to ceca. There was no difference in attachment of salmonellae to inverted washed ceca after 1, 2, 3, 5, and 10 min exposure, but a one log difference was noted between 10 min and 30 sec.     

Effects of probiotics and maternal vaccination on Salmonella enteritidis infection in broiler chicks

The effects of probiotics and maternal vaccination with an inactivated Salmonella Enteritidis (SE) vaccine on day-old chicks challenged with SE were evaluated. A 2 X 3 factorial arrangement was used (with or without probiotics; breeders nonvaccinated, vaccinated intramuscularly, or vaccinated intraperitoneally). Three trials were conducted in isolation cabinets and SE challenge was different between trials. The number of SE organisms per chick and the time interval between housing and introduction of seeder birds (hereafter called challenge) were 1.6 X 10(8) and 1 hr (Trial I), 1.8 X 10(6) and 12 hr (Trial II), and 1.2 X 10(4) and 24 hr (Trial III). SE recovery was assessed in ceca and liver at 3, 5, and 7 days postchallenge, and the number of colony-forming units (CFU) in ceca was evaluated at 5 and 7 days postchallenge. The number of SE (log CFU) in the ceca reduced 0.56 log (from 7.59 to 7.03) and 1.45 log (7.62 to 6.17) because of the treatment with probiotics in Trials II and III, respectively. The greater reduction in Trial III indicates the importance of the early use of probiotics on the prevention of SE infection. Treatment with probiotics resulted in a smaller number of SE-positive livers after 5 days postchallenge on Trial III. Although there was no significant effect of maternal vaccination on the number of SE CFU in the ceca, a significant effect of maternal vaccination on the SE CFU was observed in the liver, but not in the ceca at 5 days after challenge.     

A survey of seasonal patterns in strongyle faecal worm egg counts of working equids of the central midlands and lowlands, Ethiopia

A study was conducted for two consecutive years (1998–1999) to determine the seasonal patterns of strongyle infection in working donkeys of Ethiopia. For the purpose 2385 donkeys from midland and lowland areas were examined for the presence of parasitic ova. A hundred percent prevalence of strongyle infection with similar seasonal pattern of strongyle faecal worm egg output was obtained in all study areas. However, seasonal variations in the number of strongyle faecal worm egg output were observed in all areas. The highest mean faecal worm egg outputs were recorded during the main rainy season (June to October) in both years in all areas. Although an increase in the mean strongyle faecal egg output was obtained in the short rainy season (March–April) followed by a drop in the short dry season (May), there was no statistically significant difference between the short rainy season and long dry season (Nov–Feb) (P > 0.05). A statistically significant difference however, was obtained between the main rainy season and short rainy season, and between the main rainy season and dry season (P < 0.05). Based on the results obtained it is suggested that the most economical and effective control of strongyles can be achieved by strategic deworming programme during the hot dry pre-main rainy season (May), when the herbage coverage is scarce and helminthologically ‘sterile’, and the arrested development of the parasites is suppose to be terminating. This could insure the greatest proportion of the existing worm population to be exposed to anthelmintic and also reduces pasture contamination and further infection in the subsequent wet season.     

Afrotropical Culicoides: C. (Avaritia) loxodontis sp. nov., a new member of the Imicola group (Diptera: Ceratopogonidae) associated with the African elephant in the Kruger National Park, South Africa.

Culicoides (Avaritia) loxodontis sp. nov., is described and illustrated from both sexes collected in South Africa. It is the 5th species of the Imicola group of the subgenus Avaritia to be described from the Afrotropical Region, and is presently known only from the Kruger National Park where it has been collected in light-traps and reared from the dung of the African elephant (Loxodonta africana) on various occasions. A number of character states, and statistical analyses of antennal and palpal measurements, are used to separate the new species from its taxonomic congeners C. imicola Kieffer, 1913, C. pseudopallidipennis Clastrier, 1958, C. bolitinos Meiswinkel, 1989 and C. miombo Meiswinkel, 1991. It is suggested that the occurrence of the African elephant is the primary factor that determines the distribution of Culicoides loxodontis sp. nov., and that this close association, coupled with the fact that C. loxodontis sp. nov. can be locally abundant, may result in the cycling of certain arboviruses between this biting midge and the elephant.     

Rickettsia lusitaniae sp. nov. isolated from the soft tick Ornithodoros erraticus (Acarina: Argasidae)

In this study a novel Rickettsia from the spotted fever group, isolated from Ornithodoros erraticus soft ticks collected from pigpens in the south of Portugal, is described. After initial screening revealed Rickettsia-positive ticks, isolation attempts were then performed. Successful isolates were achieved by shell-vial technique using Vero E6 cells at 28 °C. Molecular characterization of the isolate was performed based on analysis of five rickettsial genes gltA, ompA, ompB, sca1 and htr with their subsequent concatenation along with other rickettsial species resulting in a clustering of the new isolate with Rickettsia felis and Rickettsia hoogstraalii. The degree of nucleotide sequence similarity with other rickettsiae fulfills the criteria for classification of our isolate as a novel species. The name Rickettsia lusitaniae sp. nov. (= CEVDI PoTiRo) is proposed for this new species found in O. erraticus.     

土壤施用喹硫磷防治桑瘿蚊试验

经三年防治桑瘿蚊农药筛选试验和家蚕残毒测定结果表明,5%喹硫磷粉剂是取代有机氯农药防治桑瘿蚊的有效土壤处理剂.得出:(1)5%喹硫磷粉剂对防治桑瘿蚊有良好的效果.1983年小区试验校正防效为95.7%,1984年和1985年大田试验为89.14—91.56%,与有机氯农药相似.(2)施用安全,采用施药区内桑叶养蚕均无急性中毒现象发生.(3)越冬代桑瘿蚊的生活力,休眠体最强,蛹最弱,在5月中旬对越冬代桑瘿蚊的蛹期施药效果最好.但是,喹硫磷对桑瘿蚊的各个发育阶段都有良好的毒杀作用.     

Toxicoinfectious botulism in commercial caponized chickens

During the summer of 2003, two flocks of commercial broiler chickens experienced unusually high death losses following caponizing at 3 wk of age and again between 8 and 14 wk of age. In September, fifteen 11-wk-old live capons were submitted to the Iowa State University Veterinary Diagnostic Laboratory for assistance. In both flocks, the second episode of elevated mortality was associated with incoordination, flaccid paralysis of leg, wing, and neck muscles, a recumbent body posture characterized by neck extension, and diarrhea. No macroscopic or microscopic lesions were detected in affected chickens. Hearts containing dotted blood and ceca were submitted to the National Wildlife Health Center in Madison, WI. Type C. botulinum toxin was identified in heart blood and ceca by mouse bioassay tests. Enzyme-linked immunosorbent assay tests on heart blood samples were also positive for type C. botulinum toxin. Clostridium botulinum was isolated from the ceca and genes encoding type C. botulinum toxin were detected in cecal contents by a polymerase chain reaction test. Chickens are less susceptible to botulism as they age, and this disease has not previously been documented in broilers as old as 14 wk of age. Wound contamination by spores of C. botulinum may have contributed to the unusually high death losses following caponizing.