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1.
A study was conducted to determine the incidence of trypanosome infections in cattle in tsetse-free and tsetse-infested zones of the Amhara Region of northwest Ethiopia. A total of six sentinel herds were established and the cattle observed during a period of 8 consecutive months. The prevalence of seropositive cattle was high in both the tsetse-free and tsetse-infested zones. The average monthly incidence of trypanosome infection, determined using molecular diagnostic tools, was 20.9% and 25.7% in the tsetse-free and the tsetse-infested zones, respectively. In the tsetse-free, Trypanosoma vivax was responsible for 90.9% of the cattle trypanosome infections. In the tsetse-infested zone, Trypanosoma congolense and T. vivax contributed almost equally to the trypanosome infections in cattle. Trypanosome infection, regardless of species, resulted in anaemia as evidenced by a significant decrease in the packed cell volume of the infected animal. The outcome of this longitudinal study suggests that control of trypanosomiasis in the Amhara Region cannot be achieved by tsetse control alone. Supplemental measures to include drug therapy and biting fly control are discussed.  相似文献   

2.
The objective of this study was to provide epidemiological information of equine trypanosomosis in the Central River Division (CRD) of The Gambia. Therefore, 2285 consultations records of equines, admitted in a gate-clinic at Sololo in CRD, were studied retrospectively. The data were recorded in the period between September 1995 and July 2002 and comprised consultations of 2113 horses and 172 donkeys.

‘Trypanosome infection’ was the most frequently diagnosed condition and accounted for 61% of the cases. Horses were more frequently diagnosed with trypanosome infections than donkeys (p < 0.001), with an occurrence of 63% compared to 43% in donkeys. In both horses and donkeys, trypanosome infections were mainly due to Trypanosoma congolense (64%) and T. vivax (32%). There was no difference observed in the occurrence of trypanosome infections in male or female donkeys (p = 0.585), but there were more female (67.8%) horses observed with trypanosome infections than male horses (60.7%; p = 0.003). There was no difference observed in the occurrence of trypanosome infections in donkeys older or younger than 1 year (p = 0.130), but more older horses (63.2% >1 year) were observed with trypanosome infections than young horses (54.5% <1 year; p = 0.033).

The number of donkeys and horses with trypanosome infections decreased during the rainy season (June–September).

The majority of equines that were admitted with trypanosome infections were severely anaemic. The average packed cell volume (PCV) declined with increasing parasitaemia (p = 0.006).

Seventy-four percent of the farmers’ predictions of trypanosome infections in their equines were confirmed by darkground-microscopy. That proved that farmers had a fairly accurate knowledge of the diseases affecting their equines.

The treatments executed at the gate-clinic were generally effective. The few (0.4%) relapses of the T. vivax infections that were previously treated with diminazene aceturate in this study were not sufficient to prove drug resistance.

The study showed that the analysis of consultation records at a gate-clinic can provide complementary information to conventional epidemiological studies in the same research area.  相似文献   


3.
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   

4.
Theileria parva is the causative agent of a lethal tick-borne disease of cattle occurring in eastern, central and southern Africa. Variations in the sensitivity of the serological and molecular tests with seasonal vector occurrence and discrepancies between low PCR prevalence and high T. parva vector density are a setback to estimate true prevalences. Therefore, the objectives of the present studies were to evaluate (1) the sensitivity of three serological tests (IFAT, ELISA and SELISA) and one molecular test (PCR) in the diagnosis of chronic T. parva infections in four different agro-ecological zones of Rwanda and (2) the effect of tick challenge and animal's age on the sensitivity of PCR. Blood samples from 635 bovines were collected in four agro-ecological zones of Rwanda. All sera were screened using the IFAT, ELISA, SELISA and PCR. The binary results of the four diagnostic tests were introduced separately for each agro-ecological zone in a Bayesian model to estimate the prevalence of T. parva infections and the sensitivity of the four diagnostic tests. All test specificities were set to 100%. The estimated T. parva prevalence was much higher (83–85%) than estimations based on single diagnostic tests. The estimated sensitivity of serological tests was relatively constant and ranged from 57 to 75% in the various areas. The sensitivity of PCR showed more pronounced variations, ranging from 66% in the low T. parva transmission (high land) zones compared to 24% in the highly vector infested (low land) zones. Calves and adult cattle (n = 194) were also sampled in regularly and irregularly dipped herds in the low land region. The apparent T. parva prevalence detected by PCR was significantly higher in calves than in adult cattle and in herds regularly treated with acaricides, while no significant differences were found with IFAT. The conditional probability that a sample was positive at PCR while it was positive at IFAT was significantly lower in adults. The implication of these findings in the use of diagnostic assays for epidemiological studies is discussed.  相似文献   

5.
The assay was aimed to isolate Toxoplasma gondii (T.gondii) strains from stray cat in Eryuan and Nujiang of Yunnan province.The cat tissues (heart,liver,lung and brain) were digested by acid pepsin solution,intraperitoneally inoculated in Kunming mice,passaged at least 3 generations,and followed by specific PCR amplification of partial B1 gene using species-specific primers.Three T.gondii isolates were isolated from 18 stray cats,PCR result showed that we got the specific target band,and the sequence result of the specific PCR product showed that it was ribosome B1 gene sequence of T.gondii. Homology comparison analysis showed that the isolates was 100.0% homology with T.gondii B1.The method of inoculation into the mice with the tissues that was digested by acid pepsin solution was an effective way to isolate T.gondii strain from animals,and the specific PCR assay was an accurate method for the rapid identification of T.gondii.  相似文献   

6.
为了分离猫源弓形虫,本试验从云南洱源、怒江两地区捕捉18只野猫,取其心脏、肝脏、肺脏、脑组织用盐酸—胃蛋白酶溶液消化处理后,腹腔接种小白鼠,将分离到的弓形虫虫株至少传3代,用特异PCR方法对所分离的虫株进行鉴定。结果表明,从18只野猫的样品中分离出3株弓形虫虫株,用特异性引物对3株虫株进行PCR鉴定,均得到弓形虫的特异性目的条带,测序结果表明所扩增出的DNA片段确为弓形虫核糖体B1基因部分序列。同源性比对分析结果显示分离株与T.gondii B1的同源性为100.0%。将动物组织用盐酸—胃蛋白酶溶液消化处理后腹腔接种小白鼠是一种分离弓形虫虫株较理想的方法,对弓形虫B1基因进行特异性扩增,可以快速地鉴定弓形虫虫株。  相似文献   

7.
Bovine theileriosis was a kind of hemo-protozoan diseases that seriously hindered the sustainable development of cattle industry.In the present study, the infection of Theileria was detected using microscopic examination and species-specifc PCR of T.annulata, T.sergenti and T.sinensis from 18 blood samples collected from a breeding cattle farm in China.Then ITS and MPSP genes were amplified and cloned using universal primers of ITS and allele-specific primers of 4 major piroplasm surface protein (MPSP) from the positive samples.The sequences were used to make alignment, polymorphism and phylogeny analysis.The results showed that 3 samples were positive for Theileria and the 3 positive samples were all the T.sergenti infection.The amplification of allelic MPSP gene of T.sergenti from the 3 positive samples showed that two of them were single infection by Ikeda-type and another one was co-infection with both Chitose-type and Ikeda-type, while Buffeli-type and Thai-type were not detected.Moreover, on the basis of phylogenetic tree constructed with MPSP gene sequences, types 1 and 2 of MPSP were confirmed to be present in the cattle farm.The results revealed that there were T.sergenti infection in the breeding cattle farm, and these parasites at least with 2 allelic MPSP gene types were present, which indicated that the immune prevention and control of the disease became more complicated.Our research laid foundation of the further study on T.sergenti infection and disease prevention and control.  相似文献   

8.
牛泰勒虫病是严重危害养牛业可持续发展的血液原虫病,本试验采用血涂片镜检和特异性PCR检测技术,对中国某种牛场的18份血样进行了泰勒虫检测,然后分别用ITS基因通用引物和4种MPSP等位基因特异性引物自阳性样品中扩增出对应的基因,克隆测序后,进行序列比对和进化分析,确定泰勒虫基因型。结果显示,自18份牛血样中检出3份阳性样品,且全为瑟氏泰勒虫感染;3个阳性样品的瑟氏泰勒虫MPSP等位基因扩增结果显示,1个阳性样品为I (Ikeda) 和C (Chitose)型的混合感染,另2个样品为I型单一感染,而均无B (Buffeli)和Thai型;用扩增的MPSP基因测序,构建进化树,确认其感染的瑟氏泰勒虫存在MPSP 1型和2型。这些结果表明,该种牛场存在瑟氏泰勒虫感染,且同时存在2种MPSP等位基因型;MPSP等位基因的复杂性可能使该病的免疫防控更加困难。本试验结果为深入研究瑟氏泰勒虫感染情况及免疫防控提供了数据支持,并为养防一体做好监控。  相似文献   

9.
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   


10.
Toxocarosis is a worldwide parasitic infection that affects both cats and dogs. Toxocara cati (Schrank, 1788) syn.Toxocara mystax (Zeder, 1800) prevalence was studied in faeces from stray cats collected from the open spaces of public institutions of Buenos Aires city, both building and surrounding open spaces are fenced off. Of the 465 samples obtained from March to June of 2005, 58.3% were found to have parasite eggs. The following parasites were identified from the 271 positive samples: T. cati (61.2%), Cystoisospora spp. (20.3%), Trichuris spp. (17.0%), Toxascaris leonina (15.1%), Ancylostoma spp. (14%) and Aelurostrongylus abstrusus (2.6%). T. cati prevalence was 35.7% (95% confidence interval: 31.2–40.1), with a 42.2% single isolations. The most frequent combination was T. cati and Cystoisospora spp. (9%). More than half the areas studied showed over 40% prevalence. Seventy-one percent of the collected samples were fresh with a variable moist consistency and 29% were older with a dry consistency. A statistically significant association was found between sample consistency and presence of parasites (χ2 = 10.81; p = 0.001) as also between sample consistency and presence of T. cati (χ2 = 11.27; p = 0.0007). Moist consistencies were significantly different from the rest: consistency (wet or dry) versus parasites (z = 1.95; p = 0.02) (95% confidence interval: 0.004–0.203); consistency (wet or dry) versus T. cati (z = 3.25; p = 0.0006) (95% confidence interval: 0.075–0.254). The cat population that inhabits these public green spaces contaminates the environment, thus transforming them into dangerous spaces with a variable rate for the human population that spends time in these places.  相似文献   

11.
In order to develop a specific tool differentiating the African field strains of Mycoplasma mycoides subsp. mycoides SC from other potentially less virulent strains, including the vaccine strains, we have developed a PCR followed by a restriction enzyme analysis (PCR–REA). This approach also differentiates the African field strains from the Australian strains and the type strain PG1. The genomic marker detected by the PCR–REA is based on a single nucleotide change in the bgl gene that codes for 6-phospho-β-glucosidase (Bgl), an enzyme that is involved in sugar metabolism.  相似文献   

12.
Over a period of one year, from February 1979—February 1980, the abomasa of four dairy cows were examined each week for the presence of parasitic nematodes. Based on the identification of adult male worms, Ostertagia ostertagi (94%) and Trichostrongylus axei (75%) were the most prevalent species, and Haemonchus contortus was absent. Total worm burdens varied from zero (one cow) to 100 890. The geometric mean total number was 3011. The geometric mean number of arrested larval stages was 685. Of the adult worm burden, more than 85% consisted of O. ostertagi, about 12% of T. axei the remaining 3% was other species. No relationship could be found between worm burdens and the age of the cow, the weight of the abomasum or the milk yield.

The adult Ostertagia burden was highest in the period July–September. The numbers and the percentages of arrested larvae were highest in winter, lowest in summer. Besides those of O. ostertagi, small numbers of arrested larvae of T. axei were observed from September onwards. Cows from farms with a zero-grazing system had significantly fewer worms than cows from other farms independently of the time of the year.  相似文献   


13.
Serum samples from 408 sheep from different regions of Chile and 447 alpacas (Llama pacos) from the north of the country were tested for Toxoplasma gondii antibodies. The indirect haemagglutination test (IHAT) was used in both species and the indirect immunofluorescence test (IIFT) was also used on the sheep samples in order to compare the performance of the tests in that species. In both tests, titers ≥1:16 were considered diagnostically significant. Sera from 49 sheep (12%) were positive to T. gondii antibodies by the IHAT. When using the IIFT, 114 sheep sera (28%) were positive. The different results obtained in sheep sera between the tests were significant (p<0.0001). No differences were observed between geographical locations or sex of the sampled sheep regarding serological detection of T. gondii antibodies in sheep. As expected, adult sheep showed higher T. gondii reactivity than young sheep (p=0.0008). The corrected prevalence of toxoplasmosis in alpaca was 16.3% (32 positive out of 447). The rather low prevalence in alpacas may be associated with their extensive management as well as the extreme climatic conditions of The Andes which apparently would not be favorable for the transmission of the parasite.  相似文献   

14.
Intestinal establishment and reproduction of adult Trichinella spiralis, Trichinella nativa, Trichinella britovi and Trichinella pseudospiralis were examined as single species or mixed species infections in foxes. This is the first study of intestinal dynamics of Trichinella spp. in a carnivore model and the results suggest that the intestinal phase is relatively short as only very few worms were recovered 10 days post-inoculation (dpi). In mixed species infection with equal doses of T. nativa and T. spiralis, molecular typing demonstrated that 64% of the intestinal worms and 78% of the muscle larvae were T. nativa. Conversely, T. spiralis dominated in the mixed species infections with T. pseudospiralis, constituting 66% of the intestinal worms and 94% of the muscle larvae. Although, the individual recoveries of intestinal worms were only up to 5.6% on day 1, and up to 1.5% on day 4 post-infection, the muscle larvae establishment was comparable to other fox studies. Infectivity, measured as muscle larvae burden did not differ among the four species of Trichinella, which is in contrast to other models with mice, rats, pigs or herbivores. Although statistically significant differences in intestinal worm burdens were found for some days, no distinct species were recovered in consistently higher numbers than the others.  相似文献   

15.
To explore the prevalence of Theileria equi (T.equi) infection in horse in Guizhou province, the antibody level and 18S rRNA gene were detected from blood samples of Guizhou pony, Southwest horse and Yili horse using competitive ELISA and PCR methods.Giemsa-stained blood smear was prepared to observe T.equi in red blood cells.Intact protozoans of T.equi were observed in red blood cells of horses at Giemsa-stained slide smears with a detection rate of 12.5%.The 18S rRNA gene fragment of T.equi was detected in Guizhou pony, Southwest horse and Yili horse, and the consistent rates with the known nucleotide sequence were 97% to 100%.The PCR result indicated that the positive rates of T.equi in Guizhou pony (76.62%) and Yili horse (73.81%) were similar, which were higher than that in Southwest horse (33.33%).Furthermore, the antibody levels against T.equi in Guizhou pony (24.68%) and Southwest horse (12.12%) were lower than that in Yili horse (31.71%).A weak correlation between the antibody level and the blood physicochemical indexes was calculated from Guizhou pony and Southwest horse, including weak positive correlations with neutrophils numbers, gamma-glutamyl transferase and creatine kinase levels, and weak negative correlations with the numbers of red blood cell, white blood cell, platelet and lymphocyte and contents of hemoglobin.It suggested that a higher proportion of T.equi infection present in three herds.  相似文献   

16.
3个马群感染马泰勒虫的分子病原学调查   总被引:1,自引:0,他引:1  
试验采用显微镜观察、PCR和竞争性酶联免疫吸附试验(competitive enzyme-linked immunosorbentassay,cELISA)等方法对贵州矮马、西南马和伊犁马的马泰勒虫病的感染状况进行研究。结果显示,从32份新鲜的血液涂片中,观察到形态完整的马泰勒虫(Theileria equi)虫体,检出率12.5%。从贵州矮马、西南马及伊犁马3个马群血液总DNA中都检测到马泰勒虫的18S rRNA基因片段,与已知序列的同源性为97%~100%;相比之下,贵州矮马与伊犁马的阳性率相近,分别为76.62%和73.81%,西南马较低,仅为33.33%。另外,经cELISA检测,与伊犁马(31.71%)相比,贵州矮马和西南马血液中抗马泰勒虫抗体的阳性率较低,分别为24.68%和12.12%,并与两个马群的血液理化指标存在一定的联系:与中性细胞数量、γ-谷氨酰转移酶和肌酸激酶的含量呈弱正相关;与红细胞、白细胞、血小板、淋巴细胞数量及血红蛋白含量呈弱负相关。这些研究结果提示3个马群中均存在较高比例的马泰勒虫感染。  相似文献   

17.
The use of a single restriction fragment length polymorphism (RFLP)-PCR assay which is able to characterise all important bovine trypanosome species was evaluated for the detection of mixed infections with Trypanosoma brucei brucei, Trypanosoma theileri, Trypanosoma congolense and Trypanosoma vivax. Results showed that mixed infections are detectable at a minimum ratio of 2%/98% of standardised DNA solutions with a concentration of 10 ng ml(-1). All mixed infections gave clear profiles that could be easily differentiated except with T. theileri and T. congolense where the T. theileri band was concealed by the T. congolense profile.  相似文献   

18.
This study aimed to clone and express cysteine proteinase (CP) gene of Theileria equi and Babesia caballi. The CP proteins were analyzed using bioinformatics tools and online databases. The total DNA of T. equi and B. caballi as the template sequence for PCR. The CP genes were cloned, expressed using the cloning technique and prokaryotic expression system, respectively. Then the recombinant CP (rCP) proteins were purified by Urea dialysis. Finally the specific reaction of polyclonal horse anti-CP serum with rCPs was analyzed through Dot blot method. The CPs were predicted and analyzed by the software MAGA, Prot Param, TMHMM, SignalP-5.0, Antibody Epitope Prediction, SYFPEITHⅡ, ProPred and EzMol2.1 respectively. The CP genes were successfully amplified from DNA of T. equi and B. caballi and expressed in the inclusion body fractions, Dot blot assay indicated that the recombinant protein could react with polyclonal horse anti - CP serum. Compared with T. equi-CP and B. caballi-CP, different protozoon CP genes were highly conserved in evolution, and phylogenetic analysis results were consistent with their protozoon taxonomy. The bioinformatics analysis revealed that two CPs are the hydrophilic protein instead of a transmembrane one, no transmembrane domain, no Th cell epitope was found, and more localized in the cytoplasm, mitochondria and nuclei. The relative molecular weight (MW) of T. equi-CP was 29 948.60, the theoretical isoelectric point (pI) was 5.53, stability coefficient was 22.50; B. caballi-CP’MW was 14 603.62, the theoretical pI was 8.54, stability coefficient was 47.69, but signal peptide was contained. The CPs have good reactionogenicity, as the hydrophilic extracellular proteins with no Th cell epitope, and more localized in the cytoplasm, mitochondria and nuclei, which helped T. equi and B. caballi avoid host immune response outside the cell membrane and the CPs involved in proliferation, differentiation and programmed cell death. In conclusion, a theoretical basis was provided for the study on CP’s functions and the pathogenesis of T. equi and B. caballi.  相似文献   

19.
A small plasmid of 2.5 kB mediating constitutive resistance to macrolide-lincosamide-(ML)antibiotics could be detected in a “canine” Staphylococcus epidermidis-culture. This plasmid, designated as pSES 1, was identified by interspecies protoplast transformation into Staphylococcus aureus RN 4220. A detailed restriction map of pSES 1 could be constructed using the restriction endonucleases Acc I, Bcl I, Cfo I, Cla I, Hind III, Hinf I, Mbo I, Sst I and Taq I. This map allowed structural comparisons of pSES 1 with plasmids from “human” Staphylococcus- and Bacillus-species, also mediating macrolide-lincosamide resistance (MLR). On the basis of its restriction map, pSES 1 proved to be similar to the plasmids pNE 131 from “human” S. epidermidis, pE 194 from “human” S. aureus and pIM 13 from B. subtilis.  相似文献   

20.
Tritrichomonas foetus is an extracellular parasite of the reproductive tract in cattle. The mechanism by which T. foetus causes abortion in cattle is largely unknown. There are no studies of infection in the cow oviducts, almost all published papers are related to vagina infection and few articles focusing on the uterus. The aim of the present study was to establish a working model of bovine oviduct epithelial cells and submit these cells to Tritrichomonas foetus interaction. Twenty bovine oviducts were obtained from cows at a commercial abattoir and T. foetus was injected through the isthmus into the oviduct lumen. The whole oviduct was analyzed by scanning and transmission electron microscopy. The results reported here demonstrate that: (1) fresh whole oviducts can be used as a good model to study parasite-host cell interaction; (2) cow oviduct epithelium has been shown to consist of two cell types: ciliated and nonciliated secretory cells, and T. foetus displayed great specificity for the nonciliated cells localized in the deeper oviduct folds; (3) T. foetus adheres as single separate cells, and maintains the flagella externalized; (4) differently from T. vaginalis, T. foetus does not change its shape during the adhesion process; and (5) oviduct cells exhibited morphological characteristics of apoptosis after trichomonadal interaction.  相似文献   

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