Anticoccidial effect of green tea-based diets against Eimeria maxima

Anticoccidial effects of green tea (GT)-based diets were evaluated in chickens following oral infection with Eimeria maxima an ubiquitous intestinal parasite of poultry that impairs the growth and feed efficiency of infected birds. Five-week-old chickens were assigned to four groups (GT 0.5%, GT 2.0%, untreated/infected and non-infected control) and each group consisted of 15 chickens. Chickens were fed a standard diet supplemented with ground green tea for 2 weeks prior to infection with E. maxima (10,000 sporulated oocysts per bird). The effects of green tea on E. maxima infection were assessed by two parameters, fecal oocyst shedding and body weight gain. The green tea-fed chickens produced significantly reduced fecal oocysts (P<0.05) when compared to the E. maxima-infected group fed standard diet. The green tea-based diet, however, did not improve body weight loss caused by E. maxima infection. This study is the first to demonstrate anticoccidial effect of green tea on Eimeria parasites.     

Atoxoplasmosis in tanagers.

Atoxoplasma spp. (extraintestinal Isospora spp.) are coccidian parasites that infect a variety of passerine species. Atoxoplasmosis has been difficult to diagnose using buffy coat and organ impression smear examinations or histopathologic examination of tissues at necropsy. The prevalence of this parasite was studied in the tanager collection of a zoological park after the death of several tanagers from confirmed and suspected infections. A polymerase chain reaction assay was used to test blood, feces, or tissue samples (or all) from 88 individuals representing 18 species. Twenty-three of 60 (38.3%) blood samples from clinically healthy birds tested positive for Atoxoplasma, and one of six fecal samples was positive. Nineteen of 32 (59.4%) tissue samples from deceased tanagers tested positive. A total of 57 other institutions were also queried regarding the presence of Atoxoplasma. The high number of Atoxoplasma-positive clinically healthy birds suggests that the parasite is prevalent subclinically within tanager collections, with young birds and stressed adults being the most likely to develop clinical disease. Thorough disinfection of enclosures, consideration of enclosure designs, and preventing fecal contamination of food and water are important methods of decreasing transmission. Selective breeding programs and regular screening of breeding pairs may be recommended to decrease transmission to susceptible offspring. Care should also be taken when housing tanagers in mixed species or in outdoor enclosures because the transmission risks between species have not been well established.     

Molecular identification of encephalitozoon hellem in an ostrich

Microsporidia are obligate, intracellular, eukaryotic parasites found in a wide variety of vertebrate and invertebrate hosts. Scientific literature contains a small number of reports of these parasites in psittacine hosts, and recently microsporidiosis was reported in the first nonpsittacine host, an ostrich. DNA was extracted from formalin-fixed, paraffin-embedded ostrich tissues, and a portion of the small subunit ribosomal RNA gene was sequenced to identify the microsporidian species. The organisms were identified as Encephalitozoon hellem, a parasite species that was first described in immunocompromised humans and recently reported in three psittacine species.     

Syngamiasis in juvenile American robins (Turdus migratorius), with a note on the prevalence of other fecal parasites

Of 105 juvenile American robins (Turdus migratorius L.) examined for fecal parasites, 77.1% were infected with one or more species of endoparasite. Syngamus sp. was the most commonly encountered parasite, found in 57.1% of the birds. There was a significant association between the presence of Syngamus sp. eggs in feces and signs of respiratory-tract disease. A single oral dose of fenbendazole (100 mg/kg of body weight) eliminated Syngamus sp. infection from all of 18 birds treated, yet 10 of 16 untreated controls apparently were "self-cured" over the 12-day period of observation.     

Impact of internal parasites on beef cattle

Internal parasitism is a pervasive constant that reduces returns in beef cattle production. Parasitism may influence production sufficiently so that data derived investigating performance response will be erroneous. The interaction of internal parasites of cattle with other facets of their lives makes it imperative that more parasite research be done on cattle to consider their impact. Results of trials designed to determine forage production at various stocking densities may not reflect the nutritive value of the forage, but instead the severity of parasite exposure. Relative resistance or susceptibility to certain parasites vary with the breed of livestock and the species of parasite. Extensive work to evaluate the ability of various breeds and sires to influence parasitic numbers has been conducted in sheep but not in cattle. Some parasite trials have ignored the effects of nutrition on the establishment and retention of parasites. This becomes especially important where multiple parasite exposure may occur. Susceptible cattle, even on an optimal diet, will become parasitized, but if reexposed to the same species of parasite, cattle on an optimal diet may be able to resist reinfection, whereas those on deficient diets will not.     

A survey of selected parasitic and viral pathogens in four species of Mexican parrots, Amazona autumnalis, Amazona oratrix, Amazona viridigenalis, and Rhynchopsitta pachyrhyncha.

Isolated populations of four species of Mexican parrots were sampled for evidence of selected pathogens of concern in birds originating in Latin America. Data were collected between June and September 1997, and ectoparasite collection was repeated with Rhynchopsitta pachyrhyncha in September 2000. Serum samples from nine Amazona oratrix, 10 Amazona viridigenalis, 6 Amazona autumnalis, and 25 R. pachyrhyncha chicks were screened for neutralizing antibodies to psittacid herpesvirus and avian influenza and for antibodies to paramyxovirus serotypes 1 and 3. Chicks were also examined visually for fecal parasites and ectoparasites. All serologic and fecal parasite tests were negative. Ectoparasites included ticks, Ixodidae; mites, Ornithonyssus sylviarum; fleas, Psyttopsylla mexicana; lice, Paragoniocotes mexicanus, Heteromenopon sp., and Psittacobrosus sp.; and bugs, Ornithocoris sp. This study provides baseline information to guide future health studies.     

Effects of supplemental feeding on gastrointestinal parasite infection in elk (Cervus elaphus): preliminary observations

The effects of management practices on the spread and impact of parasites and infectious diseases in wildlife and domestic animals are of increasing concern worldwide, particularly in cases where management of wild species can influence disease spill-over into domestic animals. In the Greater Yellowstone Ecosystem, USA, winter supplemental feeding of Rocky Mountain elk (Cervus elaphus) may enhance parasite and disease transmission by aggregating elk on feedgrounds. In this study, we tested the effect of supplemental feeding on gastrointestinal parasite infection in elk by comparing fecal egg/oocyst counts of fed and unfed elk. We collected fecal samples from fed and unfed elk at feedground and control sites from January to April 2006, and screened all samples for parasites. Six different parasite types were identified, and 48.7% of samples were infected with at least one parasite. Gastrointestinal (GI) nematodes (Nematoda: Strongylida), Trichuris spp., and coccidia were the most common parasites observed. For all three of these parasites, fecal egg/oocyst counts increased from January to April. Supplementally fed elk had significantly higher GI nematode egg counts than unfed elk in January and February, but significantly lower counts in April. These patterns suggest that supplemental feeding may both increase exposure and decrease susceptibility of elk to GI nematodes, resulting in differences in temporal patterns of egg shedding between fed and unfed elk.     

福州动物园圈养鸟类肠道寄生虫调查

为调查福州动物园圈养鸟类消化道寄生虫感染情况,采集16种禽类31份粪便样品,应用饱和盐水漂浮法和自然水洗沉淀法收集虫卵,麦克斯特计数法对采集的粪便样本进行虫卵测定。检查结果显示,寄生虫感染阳性样品数有23份,占样品总数的74%。总共检出6种寄生虫感染,按感染例数从大到小排序为:球虫(9例)、吸虫(7例)、绦虫(6例)、线虫(5例)、鞭虫(4例)、纤毛虫(3例)。感染寄生虫的禽类中,孔雀的感染强度最高,EPG为9 150个/g;其次是巨嘴鸟,EPG为4 500个/g;第三是东方白鹳,EPG为3 300个/g。其他鸟类的EPG分布在0~2 100个/g。该调查结果为福州动物园圈养鸟类寄生虫病的防治以及制定科学的驱虫程序提供可靠的依据。     

Biomedical evaluation of free-ranging ring-tailed lemurs (Lemur catta) in Tsimanampetsotsa Strict Nature Reserve, Madagascar.

Complete health assessments were performed on 20 adult ring-tailed lemurs (Lemur catta), 10 males and 10 females, free ranging within the Tsimanampetsotsa Strict Nature Reserve in southwest Madagascar. Each animal was anesthetized using tiletamine and zolazepam, weighed, and given a thorough physical examination. Blood was collected for hematology, determination of plasma total protein concentration, serum chemistry, determination of fat-soluble vitamin and trace mineral concentrations, assessment of iron metabolism, toxoplasmosis and viral serologies, and examination for parasites. Feces were collected for bacterial culture and parasite examination, and representative numbers of ectoparasites were collected. Blood values differed significantly in a number of ways from values in captive lemurs, possibly associated with recent food consumption, hydration, and diet. There was no evidence of serious infectious disease and no hemoparasites. The enteric flora appeared unremarkable, although results may have been skewed toward cold-tolerant bacteria. The fecal parasite burden was low, but there were large numbers of ectoparasites (mites) present. Our study demonstrated that a substantial amount of data can be collected from free-ranging populations, information that is invaluable in the management of captive populations, particularly with regard to disease, and in assessing risks associated with reintroduction programs.     

Waterfowl parasites

Waterfowl, whether free-living or in captivity, are hosts to a wide variety of internal and external parasites. With few exceptions, the significance of most parasitic infections is unknown, due, in part, to the fact that mixed parasitic infections are the rule rather than the exception. Therefore, effects of any one parasite species must be made in light of the other parasites, diseases, or stressors (eg, malnutrition) that may be present. Furthermore, the pathogenicity of a parasite may differ among species of birds as well as different populations of the same species. Experimental assessment of the effects of some parasites have been attempted using the mallard duck as the model; however, in light of species differences, the applicability of such studies to other species of waterfowl is unclear. Of the several hundred parasites that are present, nasal leeches, Leucocytozoon simondi, certain species of coccidia, some nematodes, the trematode Sphaeridiotrema globulus, cestodes in the genus Gastrotaenia, and some acanthocephalans have been associated with morbidity and/or mortality in captive or wild waterfowl. Detection of many parasitic infections can be accomplished through traditional diagnostic techniques (eg, fecal flotation, blood smears); however, the presence of parasites does not automatically equate with the presence of disease. Control and treatment measures are few, especially for free-ranging waterfowl. However, excellent sanitation can help combat many parasites in captive situations.     

Accurate diagnosis of Giardia spp and proper fecal examination procedures

A series of investigations evaluated the ability of different testing methods - a swing-head centrifugation technique using two flotation solutions (1.18-specific gravity zinc sulfate and 1.27-specific gravity Sheather's sugar solution), a passive commercial flotation technique, and the SNAP Giardia Test Kit from IDEXX Laboratories - to identify Giardia-positive dogs and recover the eggs of other intestinal parasites. It was determined that the SNAP Giardia test can improve a practice's ability to identify Giardia-infected dogs. Because of its higher specific gravity, the sugar solution was better for recovering heavy parasite eggs, such as Taenia spp, and thus is the flotation solution of choice when conducting routine centrifugation fecal examinations.     

Genotyping of Cryptosporidium spp. from free-living wild birds from Brazil

In wild and domestic birds, cryptosporidiosis is often associated with infections by Cryptosporidium galli, Cryptosporidium baileyi and Cryptosporidium meleagridis. In addition to these species, a number of avian Cryptosporidium species yet to be fully characterized are commonly found among exotic and wild avian isolates. The present study aimed to detect and identify samples of Cryptosporidium spp. from free-living wild birds, in order to contribute to the knowledge of the variability of this parasite in the free-living population of Brazil. Stool samples were collected from 242 birds, with the following proportions of individuals: 50 Emberizidae (20.7%), 112 Psittacidae (46.3%), 44 Cardinalidae (18.2%), 12 Turdidae (5.0%), eight Ramphastidae (3.3%), seven Icteridae (2.9%), three Estrilididae (1.2%), two Contigidae (0.8%), two Thraupidae (0.8%) and two Fringilidae (0.8%). Among the 242 fecal samples from wild birds, 16 (6.6%) were positive for the presence of oocysts of Cryptosporidium. Molecular characterization of the 16 samples of Cryptosporidium, were performed with phylogenetic reconstructions employing 292 positions of 18S rDNA. None of the samples of birds was characterized as C. meleagridis. C. galli was identified in one rufous-bellied thrush (Turdus rufiventris), five green-winged saltators (Saltator similis), one slate-coloured seedeater (Sporophila schistacea), one goldfinch (Carduelis carduelis) and three saffron finches (Sicalis flaveola). One goldfinch isolate, one buffy-fronted seedeater (Sporophila frontalis), one red-cowled cardinal (Paroaria dominicana) and one other saffron finch (S. flaveola) were identified as C. baileyi. Avian genotype II was found in an isolate from a white-eyed parakeet (Aratinga leucophthalma). Clinical symptoms of cryptosporidiosis in birds have already been described and the number of wild birds which were shedding parasites was high. Therefore, further epidemiological research and disease surveillance of birds in the wild is warranted.     

The role of molecular biology in veterinary parasitology

The tools of molecular biology are increasingly relevant to veterinary parasitology. The sequencing of the complete genomes of Caenorhabditis elegans and other helminths and protozoa is allowing great advances in studying the biology, and improving diagnosis and control of parasites. Unique DNA sequences provide very high levels of specificity for the diagnosis and identification of parasite species and strains, and PCR allows extremely high levels of sensitivity. New techniques, such as the use of uniquely designed molecular beacons and DNA microarrays will eventually allow rapid screening for specific parasite genotypes and assist in diagnostic and epidemiological studies of veterinary parasites. The ability to use genome data to clone and sequence genes which when expressed will provide antigens for vaccine screening and receptors and enzymes for mechanism-based chemotherapy screening will increase our options for parasite control. In addition, DNA vaccines can have desirable characteristics, such as sustained stimulation of the host immune system compared with protein based vaccines. One of the greatest threats to parasite control has been the development of drug resistance in parasites. Our knowledge of the basis of drug resistance and our ability to monitor its development with highly sensitive and specific DNA-based assays for 'resistance'-alleles will help maintain the effectiveness of existing antiparasitic drugs and provide hope that we can maintain control of parasitic disease outbreaks.     

Internal parasites of Washington cattle.

The occurrence of internal parasites in Washinton cattle was estimated. During the survey period in 1972 and 1973, more than 3,700 fecal samples from 29 herds and 4 feedlots, and viscera from 55 cattle were examined. The percentage of fecal samples with parasite eggs or oocysts from herds was as follows: oocysts, 77%; "strongyline" eggs, 44%; Nematodirus eggs, 3%; Moniezia eggs, 3%; Fasciola eggs, 2%; Trichuris eggs, 2%; and Dictyocaulus larvae, 1%. The fecal samples from feedlots contained principally strongyline eggs which varied markedly in numbers among groups of cattle in the lots. The predominant parasite in viscera was Ostertagia spp, which was recovered from all of the cattle examined. Other parasites identified in the survey were found less frequently in these examinations. Cattle in dairy and beef operations utilizing irrigated pastures were particularly prone to Fasciola infections, and more strongyline eggs were observed there than in fecal samples from other management systems. Seasonal fluctuations in numbers of strongyline and Fasciola eggs were pronounced.     

动物园鸟类肠道寄生虫感染情况调查及治疗效果分析

应用离心沉淀法和饱和蔗糖溶液漂浮法对郑州市动物园鸟类进行肠道寄生虫感染情况调查。对62种鸟类共110份粪便样品进行调查,查出2种寄生虫,寄生虫总感染率为20%,球虫和毛细线虫的感染率分别为18.08%和3.64%。此次调查寄生虫总感染率比2004年降低了40.31%,感染强度也明显降低;与2006年和2007年的感染情况基本一致,表明对动物园鸟类肠道寄生虫应进行长期监控。     

广东省部分地区马肠道寄生虫感染情况调查

【目的】调查广东省内部分地区马匹寄生虫感染情况,探索区域内马匹寄生虫感染优势虫种、感染情况和耐药情况,为区域内马肠道寄生虫病的防治提供参考。【方法】采用饱和食盐溶液漂浮法和饱和蔗糖溶液漂浮法对广东省内7个城市24个马术俱乐部375份新鲜马粪样品进行处理,光学显微镜下观察虫卵/卵囊的形态结构特征并进行分类,并根据麦氏计数法计算每克粪便中虫卵/卵囊数（EPG）,统计感染率和感染强度。对EPG＞500的阳性样本进行粪便虫卵减少量计数试验（FECRT）,以评估各马术俱乐部流行寄生虫耐药情况。提取5份＜1岁幼驹的粪便样本DNA,利用巢式PCR检测样品是否存在隐孢子虫感染。【结果】375份样品中有120份样品呈寄生虫虫卵/卵囊阳性,总感染率为32.00%。共检出4种肠道寄生虫,分别为圆线虫、马副蛔虫、类圆线虫和马蛲虫,总感染率分别为30.40%、3.70%、0.80%和0.30%。1~4岁马匹感染率显著高于其他年龄段（P＜0.05）,但不同性别马匹寄生虫感染情况无显著差异（P＞0.05）。受调查马匹感染强度以低排卵（EPG＜200）为主,占马匹总数83.47%。FECRT结果显示,样本所在马术俱乐部常用驱虫药（主要成分为伊维菌素、阿苯达唑）有效,未见耐药现象。5份＜1岁幼驹的粪便样本隐孢子虫巢式PCR检测均为阴性。【结论】广东省部分地区马术俱乐部道寄生虫防控情况总体良好,区域内各马术俱乐部寄生虫防控效果存在差异,建议区域内各马术俱乐部加强马肠道寄生虫监测工作,依据本场监测情况合理用药,避免场内流行寄生虫对所用驱虫药物产生耐药性。     

Intestinal parasites of baboons (Papio cynocephalus anubis) and chimpanzees (Pan troglodytes) in Gombe National Park.

A survey of gastrointestinal parasites of nonhuman primates in Gombe National Park, Tanzania, was conducted during July and August 1989. Fresh fecal samples collected from 35 baboons (Papio cynocephalus anubis) and 20 chimpanzees (Pan troglodytes) were analyzed for intestinal parasites. Parasite identifications were based upon the size and appearance of eggs and larvae on both direct and fecal flotation examinations. Seven species of helminths and three species of protozoa were noted in the chimpanzees, and seven species of helminths, two species of trematodes, and one species of protozoa were noted in baboons. An unidentified parasite, with a thick egg shell similar to that of ascarids, was noted in both the chimpanzee and baboon population. Unfortunately a definitive identification of this parasite could not be made based upon egg size and morphology alone and insufficient numbers of larva were present to aid identification. One previously unreported parasite, Schistosoma mansoni, was identified in the baboon population. This is the first report of a schistosome in Gombe's nonhuman primate population.     

美洲狼尾草不育系、恢复系及杂种F_1的RAPD分析

利用 RAPD技术对美洲狼尾草不育系 2 3A、2 3DA、85 DA,恢复系 3B- 6及其相应的 3个F1杂交种基因组 DNA进行了多态性分析 ,摸索出一套适合美洲狼尾草 DNA提取、PCR扩增方法。对随机选取的 2 7个引物进行扩增 ,结果有 5个引物扩增出多态性条带 ,其中引物S369扩增的条带不仅重复性好 ,而且清晰 ,为美洲狼尾草亲本材料及其杂交种鉴定和纯度分析提供了一种快速、准确的检测手段。     

Occurrence of Baylisascaris transfuga in wild populations of European brown bears (Ursus arctos) as identified by a new PCR method

The European brown bear (Ursus arctos) is a species present in limited areas of Europe and several small populations are considered endangered. This species can be affected by a range of parasites. In particular, the genus Baylisascaris is an emerging parasite of wild animals which can cause severe larva migrans syndrome in aberrant hosts, which include 100 species of birds, mammals and also humans. Baylisascaris transfuga is the species reported from bears, and with the exception of a few laboratory trials, little is known about the capacity of this species to infect other animals. Furthermore, the identification of this species has traditionally been based on light microscopy, using either morphology of the adults at necropsy or detection of the eggs in faeces, which are methods limited by the experience and the efforts of the observer. The current work was aimed at developing a specific PCR to detect the parasite directly from faecal samples of naturally infected brown bears in the field, without the need for previous flotation. Using eggs and adults of B. transfuga collected in Croatia, we first developed a PCR to detect a portion of the second internal transcribed spacer region (ITS-2) of ribosomal DNA and then applied it to bear faecal samples spiked with a known number of B. transfuga eggs. We show here for the first time that this method allows the detection of a minimum of two Baylisascaris eggs in 25mg of faecal material, thus it demonstrates a high diagnostic capacity that could be applied to evaluate the prevalence of the parasite in faecal samples from wild populations of brown bears.     

Relationships in broiler chickens between lameness, liveweight, growth rate and age

Thirteen genotypes of poultry were selected to represent a wide range of growth profiles and were fed either a non-limiting or Label Rouge diet. The birds' degree of lameness and liveweight were measured after 54 and 81 days. The birds reared on the Label Rouge diets were less lame than birds of the same genotype reared on the non-limiting diet. More traditional and slower growing genotypes tended to be less lame than the modern genotypes reared on the same feeding regimen. All the birds, irrespective of their genotype or diet, were less lame after 54 days than after 81 days. However, when liveweight was included in the analysis as a covariable, many of the differences disappeared. Only age at assessment significantly affected the walking ability of the birds, with the birds being approximately 0.6 units of gait score worse at 54 days of age than at 81 days. The regression coefficient between gait score and liveweight was 1.262 at 54 days and 1.128 at 84 days. The results indicated that liveweight was an important determinant of lameness in the diverse range of genotypes examined, that growth rate was also an important determinant of lameness and that younger birds may be more sensitive to differences in liveweight than older birds.