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1.
The prevalence of Trypanosoma evansi infection among camels and horses in Jordan was studied using thick blood smears and inoculation techniques with mice and rats. A total of 437 camels and 83 horses from four climatic zones were surveyed. In addition, 40 donkeys, 32 cattle and 35 goats in contact with infected camels and horses were also tested in the same way. Clinical disease was evident in 8.2% of the camels (36 out of 437) and in 9.6% of the horses (8 out of 83). Infection was limited only to the Sweama area on the Dead Sea (within the warm desert-climatic zone), with prevalence of 30.5% and 33.3%, respectively, for camels and horses. Donkeys, cattle and goats examined were all free from T. evansi. Clinically affected camels were positive by both, thick blood smear and mouse and rat inoculations. Rat and mouse inoculations revealed (X2=3.2, df=1, exact p=0.07) greater number of positive cases in horses than those revealed by thick blood smears. T. evansi-infected camels and horses showed all the clinical signs known for Surra. In addition, it was observed that 100% of infected camels stared at the sun.  相似文献   

2.
Organisms in the genus Anaplasma are obligate intracellular pathogens that multiply in both vertebrate and invertebrate hosts. The type species, Anaplasma marginale, causes bovine anaplasmosis and infects erythrocytes of the vertebrate host and undergoes a complex developmental cycle in ticks which serve as biological vectors. Infected cattle, wild ruminants and ticks can all serve as reservoirs of A. marginale. In this study, hunter killed Iberian red deer (Cervus elaphus hispanicus) from the region of Castilla-La Mancha in southwestern Spain were tested for Anaplasma infection. We found that 10% of the deer examined were seropositive for Anaplasma. Three A. marginale strains were subsequently obtained from salivary glands of Hyalomma marginatum that were removed from these deer, and the sequence of the major surface protein (msp)4 gene was determined for each strain and used for phylogenetic studies. Maximum parsimony analyses of msp4 sequences from H. marginatum ticks in comparison with New World cattle and bison isolates reported previously, suggested different origins for these Spanish A. marginale strains. The results of this study demonstrated that Iberian red deer are naturally infected with Anaplasma, and may therefore serve as a wildlife reservoir of the pathogen. Although the link between deer infection and the strains of A. marginale identified in ticks was not established, H. marginatum and Rhipicephalus bursa were identified as potential biological vectors for A. marginale in this region and may effect transmission of A. marginale between deer and cattle populations.  相似文献   

3.
One hundred fifty-nine Holstein calves were imported into St. Lucia from the U.S.A. An outbreak of babesiosis occurred 17 days post-arrival, and an outbreak of anaplasmosis occurred 5 months after importation. Sera obtained 3, 6 and 12 months post-importation revealed a high prevalence of IFA titres to Babesia bovis and B. bigemina 3 months after arrival and an increase in titres to Anaplasma marginale 6 months after arrival. Sera obtained arrives from native cattle from several places on the island indicated infection rates of 80, 65 and 64% with A. marginale, B. bigemina and B. bovis, respectively. The rapid card test only indicated a 25% prevalence of infection of native cattle by A. marginale. This low prevalence was probably due to deterioration of serological activity during shipment.  相似文献   

4.
在相同的饲养管理条件下,在冬、夏两季随机抽取3种牛的血液样品,使用可见光分光光度法、原子吸收与荧光分光光度法,分别对3种牛的抗氧化指标T-SOD、Cu/Zn-SOD、GSH-Px、T-AOC、MDA以及血清微量元素Se、Cu、Zn、Mn进行系统测定与分析。试验结果表明:冬季,引进娟珊奶牛和荷斯坦奶牛的T-SOD、Cu/Zn-SOD、T-AOC、Cu、Zn、Mn均高于中国本地荷斯坦奶牛,差异显著(P<0.05),GSH-Px与本地荷斯坦奶牛比较差异不显著(P>0.05);夏季,引进娟珊奶牛、荷斯坦奶牛、本地荷斯坦奶牛的T-SOD、Cu/Zn-SOD、GSH-Px、Mn、Se差异不显著(P>0.05)。引进娟珊奶牛的T-AOC显著高于荷斯坦奶牛,差异显著(P<0.05);从对相同季节的分析可知,夏季引进娟珊奶牛,其适应性有一定的提高。  相似文献   

5.
AIMS: To quantify the numbers of live cattle, sheep and poultry imported into New Zealand and, where possible, their country of origin from 1860 to 1979.

METHODS: Information on the origin and number of live animal importations into New Zealand was collected for cattle, sheep and poultry for the period 1868–1979 from the annual reports compiled by the New Zealand Registrar General's Office, Government Statistician's Office, Census and Statistics Office, Census and Statistics Department, Customs Department and Department of Statistics. Census data from 1851 to 1871 were also used to estimate the livestock population during this period. The number of animals imported and the mean population for each species in a decade were determined, and the major countries of origin were identified.

RESULTS: A large number of cattle (53,384) and sheep (604,525) were imported in the 1860s, and then there was a marked reduction in importations. Live poultry were imported in relatively small numbers (20,701) from 1880 to 1939, then 1,564,330 live poultry were imported between 1960 and 1979. Australia was the predominant country of origin for sheep between 1868 and 1959 (51,347/60,918; 84.3%) and of cattle between 1868 and 1979 (10,080/15,157; 66.5%). Only 6,712 (11.0%) sheep and 3,909 (25.8%) cattle were imported from the United Kingdom over the same periods, and even fewer from other countries.

CONCLUSIONS: The collated data and historical reports show that from 1860 to 1979 Australia has been the main source of livestock introduced into New Zealand. The pattern of importation showed that large numbers of cattle and sheep were initially imported in the 1860s, probably in response to rapid agricultural expansion. Thereafter importations continued at much reduced numbers. In contrast, relatively small numbers of poultry were introduced until the 1960s when large numbers were imported as part of the development of a modern high-production industry. The overall pattern for both cattle and sheep was of a bottleneck event, as initially a relatively limited number of animals arrived from outside populations, followed by population expansion with ongoing but limited immigration (admixture). Investigation into the genetic population structure of New Zealand's cattle and sheep, as well as their host-associated microorganisms, could reflect the impact of these early historical events.  相似文献   

6.
The Brazilian Pantanal is a 138 000 km2 tropical seasonal wetland located in the center of South America bordering Bolivia and Paraguay. The Pantanal contains approximately 1100 cattle ranches, 3 million cattle, 49 000 horses and a unique diversity of wildlife. Cattle ranching is the most important economic activity in the Pantanal. This study explores the direct financial impacts of the adoption of seven treatment strategies for the control of Trypanosoma evansi in the Brazilian Pantanal. T. evansi adversely affects the health of the horse population in the region. Horses are indispensable to the cattle ranching industry in the Pantanal. Estimated costs include risk of infection, costs of diagnosis, alternative treatments, collecting animals for treatment, and costs of animal losses. The estimated total cost of T. evansi to the Pantanal region's cattle ranchers is about US$2.4 million and 6462 horses/yr. Results indicate that one preventive and two curative treatment strategies are financially justifiable. The best available technology for the treatment of T. evansi from an economic perspective is a curative treatment employed year-round. This treatment represents an annual net benefit of more than US$2 million or US$1845/ranch and spares about 5783 horses. It represents an annual net benefit of over US$200 000 and 600 horses relative to the currently most widely adopted strategy.  相似文献   

7.
The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA) to detect antibodies; to Babesia bovis was evaluated in 1000 sera from Holstein heifers. Five hundred of them were from cattle naturally or experimentally infected with B. bovis and 500 from uninfected heifers born and raised in a region free of the vector of cattle babesiosis. Additionally, the ELISA was evaluated and compared with an indirect immunofluorescent antibody (IFA) test in 374 heifers inoculated with different kinds of B. bovis antigens in four trials. The cross-reaction was also evaluated in 50 heifers infected with Babesia bigemina and 50 heifers infected with Anaplasma marginale. The mean percentage positivity of negative sera in relation to the ELISA strong positive sera was 8%. The seropositive/seronegative cutoff point was set as twice the mean percentage positivity of negative cattle sera ( = 16%). The sensitivity of the ELISA was 98% with a 95% confidence interval (CI) of 96–99%. The specificity was 95% (CI 93–97%). The agreement was 97% and the kappa value was 0.93. The predictive values of positive and negative results were 95% and 98% respectively. ELISA showed a similar sensitivity to that of the IFA test to detect antibodies to different B. bovis antigens. Its sensitivity ranged from 97.1% to 100% (CI 89–100%), while the sensitivity of the IFA test ranged from 92.8% to 100% (CI 83–100%). ELISA cross-reacted in 8% and 6% of the sera carrying B. bigemina and A. marginale antibodies, respectively, while the IFA showed 4% cross-reaction in each situation. The ELISA evaluated has the advantages of a proper sensitivity, objectivity and capacity to be adapted to test large number of samples in a short period of time. The results indicate that the ELISA is a suitable replacement for the IFA test to detect B. bovis antibodies in cattle sera, especially in epidemiological studies.  相似文献   

8.
The effect of controlled amounts of exercise on the outcome of Trypanosoma evansi infection was studied in groups of swamp buffaloes (Bubalus bubalis) experimentally infected with T. evansi. Daily body temperature, packed cell volume (PCV) and parasitaemia measurements were obtained from each animal for up to 110 days after infection. Exercise did not appear to exacerbate the effect of T. evansi infection in that similar temperature, PCV and parasitaemia profiles were obtained with both exercised and rested animals. Trypanosoma evansi infection, however, had a marked effect on temperature and PCV profiles, both of which could adversely affect an infected animal's work output and work tolerance.  相似文献   

9.
During June–July 2000, an outbreak of surra occurred on an equine breeding farm in Khonkaen Province, Thailand. Forty-two percent of pregnant mares aborted or gave stillbirth and 40% (19/47) of horses and 10% (1/10) of mules died from surra. In August 2000 Trypanosoma evansi were detected in the remaining animals (28 horses and nine mules) on the farm by blood smear and/or the haematocrit centrifuge technique. All animals were treated with diminazene aceturate at 3.5 mg/kg body weight by intramuscular injection on days 0 and 41 of the study. Blood samples of eight randomly selected horses and mules were collected on days 0, 1 and once a week until day 56 and examined for T. evansi by various parasitological techniques. The sera were tested for antibodies against T. evansi using an indirect enzyme linked immunosorbent assay (ELISA).

The results revealed that diminazene aceturate at 3.5 mg/kg appeared to be effective in the first treatment of horses and mules infected with T. evansi. Parasites were cleared from the peripheral blood of horses on days 1 and 7 and mules on days 1 and 14. Thereafter the number of positive animals increased. After the second treatment, 50% of horses and 25% of mules were still positive to surra 24 h after treatment demonstrating that diminazene had no protective effect. Mild to severe toxicity of diminazene was seen in the horses and mules after injection.  相似文献   


10.
The indirect enzyme-linked immunosorbent assay (ELISA) for the detection of anti-trypanosomal antibodies in bovine serum was adapted for use with dried blood spots on filter paper.

Absorbance (450 nm) results for samples were expressed as percent positivity, i.e. percentage of the median absorbance result of four replicates of the strong positive control serum.

The antibody-ELISA was evaluated in Zambia for use in epidemiological surveys of the prevalence of tsetse-transmitted bovine trypanosomosis. Known negative samples (sera, n=209; blood spots, n=466) were obtained from cattle from closed herds in tsetse-free areas close to Lusaka. Known positive samples (sera, n=367; blood spots, n=278) were obtained from cattle in Zambia's Central, Lusaka and Eastern Provinces, diagnosed as being infected with Trypanosoma brucei, T. congolense, or T. vivax using the phase-contrast buffy-coat technique or Giemsa-stained thick and thin blood smears. For sera (at a cut-off value of 23.0% positivity) sensitivity and specificity were 86.1 and 95.2%, respectively. For bloodspots (at a cut-off value of 18.8% positivity) sensitivity and specificity were 96.8 and 95.7%, respectively. The implications of persistence of antibodies following treatment or self-cure are discussed.  相似文献   


11.
AIM: To estimate the prevalence of Neospora infection in a sample of New Zealand beef cattle. METHODS: The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island . Sera were tested using an ELISA against Neospora tachyzoite antigen. RESULTS: The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers. CONCLUSION: Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.  相似文献   

12.
A survey to determine the incidence of parasites in cattle (n = 386) was conducted in the north eastern Free State between August 1999 and July 2000. Giemsa-stained blood smears were negative for blood parasites. A total of 94% of the cattle were sero-positive for Babesia bigemina by indirect fluorescent antibody test while 87% were sero-positive for Anaplasma by enzyme-linked immunosorbent assay. The observation of negative blood smears but high incidence of positive serological results for Anaplasma and Babesia for the same group of cattle indicates that this area is endemic for these diseases but with a stable disease situation. All the animals were sero-negative for B. bovis and this is probably because the tick vector (Boophilus microplus) which transmits the disease is not present in the Free State Province. Two tick species belonging to the family ixodidae were found on cattle, namely Boophilus decoloratus and Rhipicephalus evertsi evertsi. In the present study significant differences in seasonal burdens of B. decoloratus occurred, with the highest infestations recorded from February to June. The presence of R. evertsi evertsi throughout the year without any or with small fluctuations in winter months was observed, with a peak from February to May.  相似文献   

13.
【目的】本研究旨在研究锥虫入侵宿主细胞的机制并为其检测方法的建立奠定基础。【方法】采用已分离保存的伊氏锥虫在昆明白小鼠体内进行培养繁殖,对其鞭毛束旁棒(PFR)基因进行克隆,并构建系统发育树。通过生物信息学方法分析和预测PFR蛋白的理化特性、亲疏水性、跨膜区结构、二级结构和三级结构;构建原核表达载体pET28a-PFR,用Western blotting检测PFR重组蛋白的反应原性。【结果】在昆明白小鼠体内成功扩繁伊氏锥虫伊犁株,第5天染虫率达到最高;PFR基因PCR扩增片段大小为834 bp,与冈比亚布氏锥虫PFR基因(XP_011775815.1)相似性为99.52%,基于PFR蛋白氨基酸序列的进化树显示,该虫株与冈比亚布氏锥虫的亲缘关系也最近。PFR蛋白分子式为C1416H2286N416O442S11,理论等电点为5.74,是一种碱性、亲水性及不稳定蛋白,没有跨膜区和信号肽,有10个潜在抗原表位;主要定位于细胞质中;PFR蛋白二级结构主要由α-螺旋组成(占92.34%)...  相似文献   

14.
Babesia divergens, the main causative agent of bovine babesiosis in Western Europe, was isolated from naturally infected cattle. Ninety-six blood samples were examined by means of an in vitro culture technique in sheep erythrocytes: 19 of them were collected from animals in the acute phase of the disease with visible parasitemia on blood smears, while the 77 remaining animals showed no microscopically detectable parasites. B. divergens was cultured from the 19 first blood samples as well as from 31 samples collected from asymptomatic animals. The time period before parasites could be detected in the culture varied in the latter samples from 6 to 20 days. The effects of sampling condition (anticoagulant used) and storage length were tested. A good correlation was obtained between immunofluorescent antibody test and culture, with identical results (positive or negative) for 89.6% of the samples collected from asymptomatic animals. The sensitivity of the in vitro culture method was determined and was about 10 parasites/mL of whole blood from three independent experiments performed with three different isolates, confirming its suitability to detect and culture diverse B. divergens isolates from carrier cattle. The parasites could indeed be isolated 9 months after the acute babesiosis phase in the blood of naturally infected animals. The 50 isolates collected in this study were successfully subcultured, cryopreserved and resuscitated using the same culture medium. The in vitro isolation of B. divergens from asymptomatic carrier cattle was achieved and will allow the analysis of parasite diversity within cattle herds.  相似文献   

15.
All the calves born (116) into 3 Maasai cattle herds in the Trans-Mara Division of Kenya, between August 1978 and October 1979, were recruited into a monthly health study which concentrated on theileriosis. Twenty-two of the calves died before they were 6 months of age, but the mortality only increased to 25% by the time the calves reached 18 months of age. The mean birth weight of calves was 17.5 kg while at 190 days post-birth the mean weight was 53.4 kg. The main causes of mortality were starvation (7.8%), neonatal diarrhoea (2.6%), chronic indigestion (2.6%) and theileriosis (2.6%) due to Theileria parva and T. mutans infections. The calves were infected with ticks from birth (mostly Rhipicephalus appendiculatus and Amblyomma spp.) and the first Theileria schizonts were detected on Day 17 post birth and reached a maximum of 18.4% of calves in the 11th week post-birth. Seasonal peaks of macroschizont incidence occurred in February and July. All calves had patent Theileria piroplasm infections by the time they were 5 months old and 44% had shown patent Theileria macroschizont infections by 6–7 months of age. Generally low parasitosis of Theileria piroplasms and schizonts occurred. Serology using the indirect fluorescent antibody test showed a high proportion of calves received antibodies against T. mutans and T. parva from their dams by way of colostrum. The majority of calves also had active antibody responses against T. mutans and T. parva by the time they were 6 months of age. There was a correlation between the pre-patent period of piroplasms and active antibody responses to T. mutans and between the prepatent period of schizonts and an antibody response to T. parva. Eighteen older calves developed T. velifera infections. “Turning sickness” due to Theileria infection in the brain was detected in older cattle. Other blood parasites such as Trypanosoma vivax, T. congolense, Anaplasma marginale and Babesia bigemina occurred at patent levels at a lower incidence than Theileria spp. and did not cause disease problems in the calves. The calf population was highly resistant to theileriosis since they had a 100% morbidity, but only 2.6% mortality. Theileria infections would appear to have an important effect on the growth of calves but this and many aspects of the epidemiology of theileriosis in the area required more intensive sampling.  相似文献   

16.
An enzyme-linked immunosorbent assay (ELISA) using sonicated purified Theileria annulata piroplasms was compared with an indirect immunofluorescent antibody test (IFAT) during a vaccination trial in cattle to test different doses and passage numbers of an attenuated T. annulata-infected lymphoblastoid cell-line, and also with Giemsa-stained blood smears during an epidemiological field study of tropical theileriosis in Morocco. The sensitivities of both the ELISA (0.56) and the IFAT using T. annulata piroplasm antigen (0.56) were lower than the IFAT using schizont antigen (0.94) for detecting serum antibodies from 18 cattle immunised 38 days previously with cell-line. The ELISA was, however, the most sensitive test after 180 days (0.50 compared with 0.06 for the piroplasm IFAT and 0.39 for the schizont IFAT), and each test detected antibodies in all sera after challenge with live T. annulata sporozoites. There were minor differences in the ability of blood smear examinations and the ELISA to detect infected and uninfected cattle in the field study at the start and end of the disease season. Initially, the sensitivity and specificity of blood smears were both 0.96 and for the ELISA were 0.83 and 0.86, whereas at the end of the season sensitivity and specificity of blood smears were 0.96 and 0.86 and for the ELISA were 0.95 and 0.94. The specificity of the ELISA was affected by the presence of calves with colostral antibodies, and if these were disregarded the specificities before and after the season were 0.94 and 1.00.  相似文献   

17.
dAim:To estimate the prevalence of Neospora infection in a sample of New Zealand beef cattle.

dMethods: The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island. Sera were tested using an ELISA against Neospora tachyzoite antigen.

dResults: The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers.

dConclusion: Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.  相似文献   

18.
Extract

The important external parasites of cattle in New Zealand include the cattle tick, Haemaphysalis longicornis, which occurs mainly in northern districts, the biting louse, Damalinia bovis, and the long-nosed sucking louse, Linognathus vituli. There are two other lice, Haematopinus eurysternus, and Solenopotes capillatus but they are much less common. The mange mite, Chorioptes bovis, occurs mainly in the winter months and causes lesions on the legs, tail and escutcheon, and in bulls it may cause severe scrotal mange similar to that seen in rams. Demodex folliculorum causes lesions deep in the skin and these constitute a serious problem in the leather industry. Stable flies, Stomoxys calcitrans, are blood suckers and their attacks worry cattle on pasture and in the milking sheds. At milking time they may inhibit milk let-down and the teat cups may be kicked off by restless cows. Warble flies, Hypoderma spp., are seen only in imported cattle and have never become established in New Zealand.  相似文献   

19.
The study is the result of analyzing 16895 blood smears of cattle collected at 180 sites in the provinces of Manica, Sofala, Zambézia and Tete in Mozambique. Of the blood smears 73.9% were from Manica, 11.8% from Tete, 8.5% from Sofala and 5.8% from Zambézia; 75.6% of these were collected from smallholder cattle. Infections with trypanosomes were highest in smallholder cattle from Sofala Province with 36.8% of the 872 blood smears examined positive for trypanosomes, and lowest in cattle of commercial farmers in Manica Province with only 6.2% of 2252 blood smears being positive. Trypanosoma congolense was the predominant species, followed by Trypanosoma vivax and Trypanosoma brucei sensu lato. Trypanosoma brucei, which also infects humans, was more frequent in the districts of Buzi, Mutarara and Morrumbala with 15.1%, 10.5% and 9.8% of all examined cattle in 2005 being infected with it, respectively. The results show a significant increase in the infection rate with trypanosomes compared with results obtained in previous years by the Regional Veterinary Laboratory in Manica Province and by the Regional Tsetse and Trypanosomiasis Control Programme in Zambézia, Tete and Sofala provinces.  相似文献   

20.
The incidence of blood parasites in trade cattle was surveyed with emphasis on tick-borne parasites, using blood smears and immunofluorescent antibody (IFA) techniques. With the blood smear method, about 9 and 8.9% of cattle examined were found positive for Babesia bigemina and Anaplasma marginale, respectively. Percentage infections with other parasites were 3.33, 1.92, 0.75, 0.75 and 0.58, respectively, for Babesia bovis, Trypanosoma brucei, Anaplasma centrale, Eperythrozoon and Theileria species as well as Trypanosoma congolense. The incidence of A. marginale infection was at its peak during the rainy season while B. bigemina was most prevalent during the dry season. There were mixed infections of Anaplasma and Babesia (1.42%); Babesia and trypanosomes (1.00%); Babesia and Eperythrozoon (0.75%) and Babesia and Theileria (0.75%). Using the indirect fluorescent antibody test, 93, 55 and 68% of cattle sera examined were found to be positive for B. bigemina, B. bovis and A. marginale, respectively. Forty-nine percent of the positive sera of B. bigemina had highest titres. The importance of using serological means for determining the endemic levels of tick-borne diseases in cattle in Nigeria is discussed.  相似文献   

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