犬焦虫病的诊治体会

焦虫又称巴贝斯虫是一种寄生在易感动物红血球内生长繁殖最终破坏红细胞并介由蜱虫、壁虱叮咬传播的一种血液寄生虫。北方地区多在6～8月份,蜱虫、壁虱较为活跃时期多发,临床上常见牛马等大牲畜放牧期间感染焦虫发病的较多。近年来由于养犬量增多和临床诊断水平的提高,犬焦虫感染的病例也有逐渐上升的趋势。犬焦虫分两种,Babesia canis又名犬焦虫;小焦虫是指Babesia gibsoni又名吉布松氏焦虫。大多数是由前者造成感染,少部分则是由后者引起。通常后者的感染比较严重,而前者的感染则有不同的病程。犬焦虫症的潜伏期大约为10～21d,有特急性,急性,慢性,以及不显性的症状。而不显性感染的狗可能会间歇性的呈现症状。临床     

浅谈猪弓浆虫病诊断与治疗

猪弓浆虫病又称猪弓形体病,弓形体是一种组织细胞内寄生虫。1流行病学1.1易感动物及传播途径弓浆虫的宿主种类十分广泛,其终末宿主是猪,其他动物只是弓浆虫的中间宿主。人感染后多呈隐性表现,但孕妇患病可致流产或产死胎。本病主要通过猫及猫科动物引起传染,也可通过接触或生食患病动物肉     

乌龟常见寄生虫病的诊治

正乌龟寄生虫病是寄生虫侵入乌龟机体而引发的疾病。由于寄生虫种类和寄生部位不同,可分为体外和体内寄生虫,而引起的临床表现和病理变化也不相同。体内寄生虫种类有盾腹吸虫、蛔虫、蛲虫、线虫、血簇虫、隐孢球虫、锥虫和棘头虫;体外寄生虫有蜱虫、螨虫和跳蚤等,寄生虫病对乌龟的健康生长影响很大。1体内寄生虫1.1病症感染寄生虫的病龟,初期体表无特别明显的症状,一切     

一氧化氮抗寄生虫感染的研究进展

一氧化氮 (NO)在寄生虫感染过程中具有抑制或杀伤寄生虫与对宿主机体产生病理损伤的双重作用。机体内 NO的产生及抗寄生虫作用受细胞因子严格调节 ,巨噬细胞经 IFN-γ等细胞因子或脂多糖 L PS刺激后能大量表达 i N-OS,产生的 NO对球虫、弓形虫、锥虫、疟原虫、肝片吸虫、血吸虫等均有杀伤作用 ,NOS抑制剂的阻断则进一步表明 NO在寄生虫感染中的重要作用。近年来 ,关于 NO抗寄生虫感染、作用机制、NO合酶抑制剂和细胞因子影响等的研究报道日渐增多。文章就有关研究进展进行了综述     

梨形虫和伊氏锥虫双重PCR检测方法的建立

为了建立梨形虫(Piroplasmida)和伊氏锥虫(Trypanosoma evansi)的双重PCR检测方法，试验根据梨形虫的18S rRNA基因和伊氏锥虫的kDNA基因设计两对特异性引物，以吕氏泰勒虫和伊氏锥虫阳性样品DNA为模板进行单重PCR和双重PCR,并对双重PCR的退火温度进行优化，对本研究建立并优化的双重PCR方法进行特异性试验、敏感性试验及临床样品的检测。结果表明：本研究建立的双重PCR方法能够扩增出350 bp和600 bp的特异性目的条带，而无浆体、肝簇虫、弓形虫和埃立克体样品均呈阴性，梨形虫和伊氏锥虫最低检测浓度分别为54.70 fg/μL和14.30 fg/μL,用本试验建立的方法对临床样品的检测结果与对照方法(巢式PCR)检测结果一致。说明本研究成功建立了灵敏、快速、简便、特异性高的双重PCR检测方法，能够用于梨形虫和伊氏锥虫的临床检测及流行病学调查。     

牛焦虫病的防治

感染牛的寄生虫中的焦虫通常包括巴贝斯虫和泰勒虫。这两种寄生虫都通过壁虱媒介传播,并在易感牛中引起严重的临床疾病。被感染的壁虱载体在其血粉中注射的巴贝斯亚子孢子侵入牛红细胞(RBC),然后转化为无性繁殖的裂殖子。从受感染的红细胞中排出的裂殖子会导致这些细胞在血管内被大量破坏,从而导致贫血和与贫血相关的临床症状,可能会导致呼吸系统和神经系统综合征,如果延误了疾病的治疗,预后都会很差。本文综述了牛焦虫病的相关机制及防控,以期为疾病的防治奠定一定的基础。     

微嗜氧稳定期体外培养法分离巴贝西虫试验

自然感染的牛巴贝西虫（Babesiaboris）通常用来制作活疫苗和进行寄生虫的生物学研究，上述两个目的需要纯的B．boris，不能混有其他的血液寄生虫，但是B．boris的分布范围和其他的以节肢动物为媒介的血液寄生虫（包括牛泰勒焦虫（Theileria buffeli）、     

抗巴贝斯虫药物的研究进展

巴贝斯虫病广泛存在于热带和亚热带国家,给畜牧业造成严重的经济损失,目前对于巴贝斯虫病的治疗尚无特效药, 作者就近年来治疗巴贝斯虫病的药物研究现状进行综述。常用的较为有效的药物咪唑苯脲对肝功能具有损伤作用,阿托伐醌和阿奇霉素联用可造成寄生虫细胞色素b基因突变,且复发感染和寄生虫对药物产生耐药性较为严重。对于抗巴贝斯虫的化合物开发主要集中在噻唑和咪唑等杂环化合物及其衍生物等。利用分子生物学的方法寻找寄生虫中适当的靶基因并进行其颉颃剂的研究取得了一定的效果,另外还有一些试验结果显示部分传统药物对于抗巴贝斯虫有效。     

羊焦虫病的病原与诊治

焦虫病是莫氏巴贝斯虫以及山羊泰勒虫在羊血液中寄生所引起的疾病。临床上羊患病后会出现高热、贫血、黄疸等主要病症,具有很高的死亡率,1～2岁的羔羊最易患病。该疾病具有传播性,通过硬蜱吸血来实现传播,具有很大的危害性。1病原羊焦虫病的发病原因是莫氏巴贝斯虫以及山羊泰勒虫感染所致。前者是在羊血液的红细胞中寄生,具有牛双芽巴斯类似的形态,呈椭圆形或梨形等。梨形寄生虫其长度要大于红细胞半径。     

巴贝斯虫感染对宿主红细胞及免疫系统的影响

巴贝斯虫(Babesia)是一种寄生于宿主红细胞的顶复门寄生虫,硬蜱为其传播媒介。由于巴贝斯虫感染后可以引起人或动物严重的临床症状,甚至造成死亡,给畜牧业和人类健康带来了极大威胁。本文主要综合国内外近年的研究成果,从巴贝斯虫入侵红细胞并对红细胞造成的影响,宿主感染后机体免疫状态的变化,以及共感染等方面进行综述,旨在为巴贝斯虫相关研究提供参考。     

Emerging food-borne parasites

Parasitic food-borne diseases are generally underrecognised, however they are becoming more common. Globalization of the food supply, increased international travel, increase of the population of highly susceptible persons, change in culinary habits, but also improved diagnostic tools and communication are some factors associated with the increased diagnosis of food-borne parasitic diseases worldwide. This paper reviews the most important emerging food-borne parasites, with emphasis on transmission routes. In a first part, waterborne parasites transmitted by contaminated food such as Cyclospora cayetanensis, Cryptosporidium and Giardia are discussed. Also human fasciolosis, of which the importance has only been recognised in the last decades, with total numbers of reported cases increasing from less than 3000 to 17 million, is looked at. Furthermore, fasciolopsiosis, an intestinal trematode of humans and pigs belongs to the waterborne parasites as well. A few parasites that may be transmitted through faecal contamination of foods and that have received renewed attention, such as Toxoplasma gondii, or that are (re-)emerging, such as Trypanosoma cruzi and Echinococcus spp., are briefly reviewed. In a second part, meat-borne parasite infections are reviewed. Humans get infected by eating raw or undercooked meat infected with cyst stages of these parasites. Meat inspection is the principal method applied in the control of Taenia spp. and Trichinella spp. However, it is often not very sensitive, frequently not practised, and not done for T. gondii and Sarcocystis spp. Meat of reptiles, amphibians and fish can be infected with a variety of parasites, including trematodes (Opisthorchis spp., Clonorchis sinensis, minute intestinal flukes), cestodes (Diphyllobothrium spp., Spirometra), nematodes (Gnathostoma, spp., anisakine parasites), and pentastomids that can cause zoonotic infections in humans when consumed raw or not properly cooked. Another important zoonotic food-borne trematode is the lungfluke (Paragonimus spp.). Traditionally, these parasitic zoonoses are most common in Asia because of the particular food practices and the importance of aquaculture. However, some of these parasites may emerge in other continents through aquaculture and improved transportation and distribution systems. Because of inadequate systems for routine diagnosis and monitoring or reporting for many of the zoonotic parasites, the incidence of human disease and parasite occurrence in food is underestimated. Of particular concern in industrialised countries are the highly resistant waterborne protozoal infections as well as the increased travel and immigration, which increase the exposure to exotic diseases. The increased demand for animal proteins in developing countries will lead to an intensification of the production systems in which the risk of zoonotic infections needs to be assessed. Overall, there is an urgent need for better monitoring and control of food-borne parasites using new technologies.     

Cellular adhesive phenomena in apicomplexan parasites of red blood cells

The apicomplexan parasites Babesia and Plasmodium are related, yet phylogenetically distinct haemoprotozoa that infect red blood cells and cause severe diseases of major human and veterinary importance. A variety of cellular and molecular interactions are pivotal in many aspects of the pathogenicity of these two parasites. Comparison of the cellular and molecular mechanisms that culminate in accumulation of parasitised red blood cells in the microvasculature of cattle infected with Babesia bovis (babesiosis) and humans infected with Plasmodium falciparum (falciparum malaria) is particularly instructive given the striking similarities in the pathophysiology of these two important medical and veterinary diseases. While such adhesive phenomena have been studied extensively in malaria, they have received relatively little attention in babesiosis. In this review, we summarise the findings of more than 25 years of research into cellular adhesive phenomena in malaria and speculate on how this body of work can now be applied to Babesia parasites. Such information is fundamental if we are to learn more about the biology of Babesia parasites, the cellular and molecular mechanisms by which they cause infection and disease and how to develop novel therapeutic strategies or vaccines for both Babesia and malaria infections.     

Hematotropic parasites of translocated raccoons in the southeast.

Ninety-four raccoons (Procyon lotor) from 6 southeastern states were examined for hematotropic parasites, to evaluate the carrier potential of these animals as they relate to translocation and release for hunting purposes. Four species of hematotropic parasites were identified, viz, Babesia procyonis, Haemobartonella procyoni, Hepatozoon procyonis, and Trypanosoma cruzi. Lesions in infected raccoons were associated only with H procyonis. Babesia procyonis was enzootic in populations of raccoons used as sources for exportation and in raccoons resident in typical release areas. Haemobartonella procyoni, H procyonis, and T cruzi were prevalent only in locales of raccoon origin. Due to the potential pathogenicity of H procyonis and T cruzi in raccoons or other hosts, the practice of translocating raccoons from enzootic to nonenzootic areas was considered biologically hazardous.     

A preliminary disease survey in the wild Nile crocodile (Crocodylus niloticus) population in the Okavango Delta, Botswana

The objective of this study was to conduct a preliminary survey of diseases that might be present in the wild Nile crocodile population in the Okavango Delta, Botswana. Blood samples were collected from crocodiles ranging in size from 34.0 cm to 463.0 cm total length. Samples were examined for blood parasites and underwent a haematological analysis. Before release the crocodiles were examined for various clinical abnormalities. Of the 144 crocodiles examined, none were visibly sick or displayed any signs of disease. No antibodies to Mycoplasma crocodyli were detected. Hepatozoon pettiti was present in 55.3% of blood smears examined, but there was no significant difference in any of the haematological values between the infected and uninfected crocodiles, and a high prevalence of Hepatozoon infection is not uncommon in other species. Only 7.6% of the examined crocodiles were infested with leeches. Further research is required for several of the crocodilian diseases, in particular to elucidate the role of wild crocodilians as reservoirs of infection.     

Molecular characterization of Hepatozoon spp. infection in endangered Indian wild felids and canids

Hepatozoon species are parasites that infect a wide variety of domestic and wild animals. The objective of this study was to perform the molecular detection and characterization of Hepatozoon spp. in Asiatic lion, Indian tiger, Indian leopard, Indian wild dog, Indian domestic dog and cat based on partial 18S rRNA gene sequences from Hepatozoon spp. in the naturally infected animals. Hepatozoon spp. could be detected in blood samples of 5 out of 9 Asiatic lions, 2 out of 5 Indian tigers, 2 out of 4 Indian leopards and 2 out of 2 Indian wild dogs and, 2 out of 4 domestic cats and 2 out of 3 domestic dog samples by PCR. Sequencing of PCR amplicon and BLAST analysis of partial 18S rRNA gene sequences indicated that the Hepatozoon spp. in Asiatic lion, Bengal tiger, Indian leopard and domestic cat was Hepatozoon felis (98-99% similarity) and in the Indian wild and domestic dog the phylogenetic neighbour was Hepatozoon canis (97-100% similarity). Presence of H. felis and H. canis in both domestic and wild animals suggested that they are not host specific and the same parasite causes infection in domestic and wild felids and canids in India and from different parts of the world. To our knowledge, this is the first report on detection and molecular characterization of H. felis infection in Asiatic lions, Indian tigers, Indian leopards and H. canis in Indian wild dog. Hepatozoon spp. may be a potential pathogen and an opportunistic parasite in immuno-compromised animals and could thus represent a threat to endangered Indian wild felids and canids.     

Characterization of Trypanosoma (Trypanozoon) evansi from dromedary camels in Kuwait by isoenzyme electrophoresis

Blood from 115 camels in Kuwait was examined for blood parasites. Two camels of a local herd (1.7%) were found to be infected with Trypanosoma (Trypanozoon) evansi and three camels (2.6%) with microfilarial nematodes. The Trypanosoma stocks isolated from these two camels were screened for isoenzyme patterns of 10 enzymes using thin-layer starch-gel electrophoresis. The results revealed that these two stocks were identical to camel stocks of T. evansi from certain countries in Africa, as well as to two stocks isolated from dogs in Kuwait. This is the first record of Trypanosoma (Trypanozoon) evansi isolates and microfilariae from camels in Kuwait.     

Molecular characterization of Hepatozoon sp. from Brazilian dogs and its phylogenetic relationship with other Hepatozoon spp

To characterize phylogenetically the species which causes canine hepatozoonosis at two rural areas of Rio de Janeiro State, Brazil, we used universal or Hepatozoon spp. primer sets for the 18S SSU rRNA coding region. DNA extracts were obtained from blood samples of thirteen dogs naturally infected, from four experimentally infected, and from five puppies infected by vertical transmission from a dam, that was experimentally infected. DNA of sporozoites of Hepatozoon americanum was used as positive control. The amplification of DNA extracts from blood of dogs infected with sporozoites of Hepatozoon spp. was observed in the presence of primers to 18S SSU rRNA gene of Hepatozoon spp., whereas DNA of H. americanum sporozoites was amplified in the presence of either universal or Hepatozoon spp.-specific primer sets; the amplified products were approximately 600bp in size. Cloned PCR products obtained from DNA extracts of blood from two dogs experimentally infected with Hepatozoon sp. were sequenced. The consensus sequence, derived from six sequence data sets, were blasted against sequences of 18S SSU rRNA of Hepatozoon spp. available at GenBank and aligned to homologous sequences to perform the phylogenetic analysis. This analysis clearly showed that our sequence clustered, independently of H. americanum sequences, within a group comprising other Hepatozoon canis sequences. Our results confirmed the hypothesis that the agent causing hepatozoonosis in the areas studied in Brazil is H. canis, supporting previous reports that were based on morphological and morphometric analyses.     

Molecular prevalence and characterization of Hepatozoon ursi infection in Indian sloth bears (Melursus ursinus)

Hepatozoon species are parasites that infect a wide variety of domestic and wild animals. The objective of the study was to detect the occurrence of Hepatozoon ursi in Indian sloth bears and to characterize the parasite based on phylogenetic analysis of the partial 18S rRNA gene sequence. Hepatozoon infection could be detected in 38 (70%) out of fifty-four blood samples of Indian sloth bears (captive and wild), suggestive of high prevalence of Hepatozoon infection in Indian sloth bears. Sequencing of partial 18S rRNA gene of the positive samples and BLAST analysis indicated that the nearest phylogenetic neighbour was H. ursi with which they exhibited 99-100% similarity. Additionally, Hepatozoon sp. isolated from wild sloth bears of India were identical to those in captive sloth bears and phylogenetically related to H. ursi reported from Japanese black bears from Japan. To our knowledge, this is the first report on the molecular characterization of H. ursi infection in Indian sloth bears.     

Hepatozoon spp. (Apicomplexa: Hepatozoidae) infection and selected hematological values of the neotropical rattlesnake, Crotalus durissus collilineatus (Linnaeus, 1758) (Serpentes: Viperidae), from Brazil

This study aims to establish the hematological values of Crotalus durissus collilineatus snakes captured in Brazil as well as to verify the effects of hematozoan infection on these snakes. Eighty-three blood samples were drawn from C. d. collilineatus specimens for analysis. The sample set was composed of 30 males and 30 females, recently caught from the wild, and 11 males and 12 females bred in captivity. Blood samples were used to determine red blood cell counts, white blood cell counts, thrombocyte counts, hematocrit values, hemoglobin concentration, and total plasma protein. Blood smears were used to diagnose Hepatozoon spp. infection and to calculate the parasitic load in the sample as well as the percentage of immature red cells. Results obtained for the wild-caught animals, with and without parasites, were compared among themselves and with the values obtained for the captive-bred animals. Hematological values for C. durissus were established. Wild-caught snakes had an infection rate of 38.3%, while no Hepatozoon sp. infection was detected in the captive-bred animals. The snakes which were not infected by the Hepatozoon sp. exhibited average weight, length, and weight-length ratios higher than those of the infected animals. An increase in immature red cells was noted in the Hepatozoon-infected snakes.     

The prevalence of blood parasites in helmeted guineafowls, Numida meleagris, in the Kruger National Park

Bloodsmears were taken from separate groups of five helmeted guineafowls, Numida meleagris, shot at approximately monthly intervals at Skukuza and near Lower Sabie in the Kruger National Park during the period August 1988 to August 1990. Ninety-eight (86%) of 114 guineafowls had single or multiple infections of Aegyptianella sp., Haemoproteus pratasi, Hepatozoon sp., Leucocytozoon neavei, Plasmodium circumflexum and Trypanosoma numidae. The apparent seasonal prevalence of Aegyptianella sp., H. pratasi and L. neavei, the three most commonly occurring parasites (42%, 49% and 56% of birds infected respectively), is probably dependent on the presence of their respective vectors.