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1.
This paper describes an outbreak of Trypanosoma vivax for the first time in the state of Pernambuco, Brazil, affecting dairy cattle in the municipality of Itambé in the northern coastal zone of the state. Clinical signs compatible with infection by blood protozoa and epidemic miscarriages were observed. The diagnosis of T. vivax was confirmed through biometric microscopy and molecular analysis with PCR and DNA sequencing. The T. vivax isolate detected in the present study proved to be genetically very close to other Brazilian isolates of the protozoan despite being geographically distant.  相似文献   

2.
Teneral tsetse flies infected with either Trypanosoma brucei or T. vivax were fed on healthy cattle. Blood samples collected daily from the cattle were examined by microscopy for the presence of trypanosomes, in thick smear, thin smear and in the buffy coat (BC). All the cattle fed upon by infected tsetse developed a fluctuating parasitaemia. DNA was extracted from the blood of these cattle and subjected to polymerase chain reaction (PCR) using oligonucleotide primers specific for T. brucei or T. vivax. The PCR products unique to either T. brucei or T. vivax were identified following amplification of DNA from the blood samples of infected cattle, whereas none was detectable in the DNA from the blood of the cattle exposed to non-infected teneral tsetse. In a concurrent set of experiments, one of the oligonucleotide primers in each pair was biotinylated for use in PCR-ELISA to examine all the blood samples with this assay. Both the PCR and the PCR-ELISA revealed trypanosome DNA in 85% of blood samples serially collected from the cattle experimentally infected with T. brucei. In contrast, the parasitological assays showed trypanosomes in only 21% of the samples. In the blood samples from cattle experimentally infected with T. vivax, PCR and PCR-ELISA revealed trypanosome DNA in 93 and 94%, respectively. Microscopy revealed parasites in only 63% of the BCs prepared from these cattle. Neither PCR nor PCR-ELISA detected any trypanosome DNA in blood samples collected from the animals in the trypanosome-free areas. However, both assays revealed the presence of trypanosome DNA in a number of blood samples from cattle in trypanosomosis-endemic areas.  相似文献   

3.
The first outbreak of trypanosomosis caused by Trypanosoma evansi in camels in France was reported on a farm in the Aveyron Department. Five camels were imported from the Canary Islands to the farm in early July 2006, and trypanosomes were observed on a stained blood smear from one of them, which died in October. On further investigations, trypanosomes were observed in the blood of five camels, three of them indigenous to the farm and two that had been imported. On the basis of microscopical examination (morphological criteria and measurements) and serological results based on the card agglutination T evansi test and PCR typing, the parasites were identified as T evansi. After treatment with melarsomine, the infected camels rapidly became negative by parasitological tests and were negative two to four months later by serological tests. The parasite was probably transmitted by tabanids and Stomoxys calcitrans, which were abundant in July to September 2006. No parasites were observed in other animals on the farm or on neighbouring farms, but some of the sheep on these farms were positive by PCR or serology.  相似文献   

4.
Trypanosomes identified as Trypanosoma vivax were found infecting nine sheep (4.6%) and one goat (1.3%) on four of 11 farms surveyed on coastal Guyana. Animals sampled on another farm situated in the Rupununi savannahs gave negative results. Haematological techniques preferred for studies of this nature were the haematocrit centrifuge technique (HCT) and the thick blood smear technique.  相似文献   

5.
Granulocytic Ehrlichia infection in sheep is common in Norway in areas with Ixodes ricinus. In this study, 2 sheep flocks that had been grazing on I. ricinus infested pastures the previous season, were blood sampled after being housed indoors for nearly 6 months during wintertime. Thirty animals from each flock were examined for granulocytic Ehrlichia infection in the peripheral blood by blood inoculation studies, stained blood smear evaluation, polymerase chain reaction (PCR) analysis and serology (IFA-antibodies). The animals were sampled twice within a three-week period, the first time before and the second time after lambing. Two sheep in one flock were found Ehrlichia positive by both blood smear evaluation and PCR before lambing, and 3 sheep were found positive after lambing; 2 by blood smear examination and 3 by PCR. In the other flock, no sheep was found infected before lambing, but 2 ewes were found positive after lambing by both blood smear evaluation and PCR. In the first flock, 87% of the animals were found seropositive before lambing, and the mean antibody titre (log10 +/- SD) to E. equi was 2.45 +/- 0.401. In the second flock, 40% were found seropositive before lambing, and the mean antibody titre was 1.93 +/- 0.260. Seroprevalence and mean antibody titre in these 2 flocks were significantly different (p < 0.001). The present study indicates that sheep may be a reservoir host for granulocytic Ehrlichia infection from one grazing season to the next under natural conditions in Norway.  相似文献   

6.
ABSTRACT: Changes in cerebrospinal fluid (CSF) and anatomical and histopathological central nervous system (CNS) lesions were evaluated, and the presence of Trypanosoma vivax in CNS tissues was investigated through PCR. Twelve adult male goats were divided into three groups (G): G1, infected with T. vivax and evaluated during the acute phase; G2, infected goats evaluated during the chronic phase; and G3, consisting of non-infected goats. Each goat from G1 and G2 was infected with 1.25 × 105 trypomastigotes. Cerebrospinal fluid (CSF) analysis and investigation of T. vivax was performed at the 15th day post-infection (dpi) in G1 goats and on the fifth day after the manifestation of nervous system infection signs in G2 goats. All goats were necropsied, and CNS fragments from G1 and G2 goats were evaluated by PCR for the determination of T. vivax. Hyperthermia, anemia and parasitemia were observed from the fifth dpi for G1 and G2, with the highest parasitemia peak between the seventh and 21st dpi. Nervous system infection signs were observed in three G2 goats between the 30th and 35th dpi. CSF analysis revealed the presence of T. vivax for G2. Meningitis and meningoencephalitis were diagnosed in G2. PCR were positive for T. vivax in all the samples tested. In conclusion, T. vivax may reach the nervous tissue resulting in immune response from the host, which is the cause of progressive clinical and pathological manifestations of the CNS in experimentally infected goats.  相似文献   

7.
The study was carried out to detect Theileria annulata, the causative agent of theileriosis, and Babesia bovis, the causative agent for babesiosis, in Friesian cattle by PCR and conventional blood smear examination. One hundred blood samples obtained from diseased Friesian cattle kept on private livestock farms at Pattoki, District Kasur, Pakistan were collected in addition to 20 blood samples obtained from non-diseased animals. The disease manifestations observed clinically included high fever, swelling of sub mandibular and sub scapular lymph nodes, weakness, increased respiration and pulse, anorexia, loss of condition and rough hair coat. Neurologic sign of in coordination was also seen in weak animals. Signs of lacrimation, pale conjunctiva, diarrhoea, dyspnea and frothy nasal discharge were observed in only one animal. Clinically nine animals showed signs of haemoglobinuria. Diagnosis of bovine theileria and babesia species was based on finding many intraerythrocytic piroplasms of both blood protozoa with clinical signs associated with anaemia, lymph node hyperplasia and haemoglobinuria. One hundred samples of ticks were also collected for identification of vector. Results showed that the prevalence of Hyalomma tick was highest (15%) followed by Boophilus (12%), Haemaphysalis (5%) and Rhipicephalus (3%). The blood smear examination showed 21% (21/100) samples positive for blood parasites out of which 66.6% (14/ 21) samples were positive for theileriosis while 42.8% (9/21) were positive for babesiosis. It was also recorded that 66.66% (6/9) samples were positive for B.bigemina while 33.33% (3/9) were positive for B.bovis. The results showed that 60% (60/100) samples were positive for blood parasites by PCR test. Out of these 60% (36/60) were positive for T.annulata while 33.33% (20/60) were positive for babesia. The specificity and sensitivity of PCR test was higher than blood smear examination. The blood parameters in haemoparasites infection were also analyzed and the results showed significant decrease in total erythrocyte count and haemoglobin while MCV, MCH values increased and MCHC was slightly less than normal indicating macrocytic hypochromic anaemia.  相似文献   

8.
The diagnostic performance of a polymerase chain reaction assay (PCR) for monitoring the effectiveness of aceturate diminazene treatment was compared with those of an antibody-detection ELISA test and the buffy-coat technique using sheep experimentally infected with either savannah-type or forest-type Trypanosoma congolense or T. vivax. Within the period of infection, the PCR using specific savannah-type T. congolense primers showed a significant higher diagnostic sensitivity (p<0.05) than the buffy-coat technique. Both techniques gave closed results for detecting forest-type T. congolense or T. vivax infections. Following trypanocidal treatment, the PCR showed that specific product disappeared definitively 1 or 2 days later in animals in which a decrease of the antibody level and a significant improvement of the red packed cell volume were observed. The occurrence of relapse infection was detected by the PCR in one animal infected by T. vivax on day 19 post-treatment and confirmed by the persistence and increasing antibody level whereas the buffy-coat technique detected parasites 42 days later. Then, the PCR signals remained positive on several occasions while parasitaemia was detected only two times.The application of PCR combined with the antibody detection appeared to provide a useful tool as compared to the buffy-coat technique for monitoring the effectiveness of trypanocidal treatment.  相似文献   

9.
An outbreak of trypanosomiasis by Trypanosoma vivax is reported in the semiarid of Paraíba, Northeastern Brazil from May to August 2002. Sixty-four cows out of 130 were affected; 11 died and the other recovered after treatment with diminazene aceturate. Affected animals had fever, anemia, weight loss, hypoglycemia, increased serum levels of aspartate aminotransferase and, in nine cows, nervous signs. All cows with nervous signs died; six of them recovered after treatment, but the disease relapsed. Six cows aborted and one delivered a calf that died immediately after parturition. Thirty-two out of 100 calves were affected and five died. Nervous signs were not observed in the calves. Gross lesions were thickening of the meninges, enlarged lymph nodes and prominent white pulp of the spleen. The main histological lesion was meningoencephalitis and malacia in the brain of cows with nervous signs. No antibodies against trypanosomes were found in 33 blood samples collected before the outbreak in the affected farm and in 29 samples collected at the same time in two other neighbor farms. Until January 2003, all 89 animals tested had antibodies against T. vivax, suggesting the occurrence of sub clinical infections in cattle without clinical signs. Only two out of 85 serum samples collected on April 2004 were positive for T. vivax antibodies. Data obtained suggested that the semiarid region is non-endemic for trypanosomiasis and that disease occurred due to introduction of the parasite in a susceptible population after an apparent rise in the Tabanus spp. population.  相似文献   

10.
套式PCR扩增山羊吕氏泰勒虫18S rRNA基因   总被引：1，自引：1，他引：0  
泰勒虫是一种危害动物的重要血液寄生性原虫,常寄生于牛、羊、骆驼和其他野生动物,在中国的东北、西北等地较为流行。采集安徽定远县某山羊场疑似焦虫病的山羊血样,首先采用血涂片法检查,再用Blood DNA&Tissue kit提取血液基因组,参照Kim和Wei的方法设计2对引物用于泰勒虫18S rRNA基因的扩增,并对该方法进行敏感性和特异性分析。结果显示:血涂片检查明显可见红细胞内有典型的虫体,大小为0.6~2μm,初步怀疑为泰勒虫(Theileria);PCR扩增可扩增出359 bp大小目的片段,与预期结果相一致;基因序列同源性表明,该泰勒虫分离株基因与已报道泰勒虫毒株(JQ926740.1)核苷酸同源性最高,可达99.72%;在遗传进化方面,所分离的泰勒虫和吕氏泰勒虫(Theileria luwenshuni)Nanjingdong(JQ926740.1)最接近,而且在一个分支上。本试验所建立的套式PCR具有良好的特异性,且敏感性较高,最低测出量是3.8 fg/μL。本次分离的羊血液原虫为吕氏泰勒虫。  相似文献   

11.
Trypanosoma vivax and Trypanosoma evansi are livestock parasites of economic importance in Africa, Asia and South America. In the Pantanal, Brazil, they cause economic losses in both cattle and equines. Little is known of their maintenance and spread in nature, particularly in terms of reservoirs and means of mechanical transmission. Here we report for the first time the use of PCR for the detection of T. vivax and T. evansi in bovines, buffaloes and sheep. Whereas parasitological diagnosis detected only two T. vivax infections, one in buffalo and another in a cow, PCR detected infections in 34.8% buffaloes, 44.7% bovines and 37.3% sheep. Trypanozoon primers detected 41.8% infections in buffaloes and 8.1% in cattle. PCR revealed 6.9% mixed infections in buffaloes and 5.3% in cattle. The potential role of cattle and buffaloes as hosts and reservoirs of T. vivax is discussed, as well as the implications of possible extravascular foci in the maintenance of livestock trypanosomosis.  相似文献   

12.
There are several T. vivax specific primers developed for PCR diagnosis. Most of these primers were validated under different DNA extraction methods and study designs leading to heterogeneity of results. The objective of the present study was to validate PCR as a diagnostic test for T. vivax trypanosomosis by means of determining the test sensitivity of different published specific primers with different sample preparations. Four different DNA extraction methods were used to test the sensitivity of PCR with four different primer sets. DNA was extracted directly from whole blood samples, blood dried on filter papers or blood dried on FTA cards. The results showed that the sensitivity of PCR with each primer set was highly dependant of the sample preparation and DNA extraction method. The highest sensitivities for all the primers tested were determined using DNA extracted from whole blood samples, while the lowest sensitivities were obtained when DNA was extracted from filter paper preparations. To conclude, the obtained results are discussed and a protocol for diagnosis and surveillance for T. vivax trypanosomosis is recommended.  相似文献   

13.
An outbreak of trypanosomoasis caused by Trypanosoma evansi involving horses, camels and donkeys occurred in a farm in Israel. A longitudinal study of two outbreak phases was conducted which included clinical monitoring, blood smears, packed cell volume (PCV), serology and polymerase chain reaction (PCR) followed by reverse dot blot (RDB) for the molecular detection of infection. This was the first reported T. evansi outbreak in domestic animals in Israel. Most of the camels on the farm (8/10; 80%) were diagnosed with T. evansi infection whereas infection was less prevalent in the horses (3/7; 43%) and donkeys (6/13; 46%). Clinical disease was evident in 4 camels and 1 horse exhibiting characteristic clinical signs, anemia and parasitemia detected on blood smears and by positive RDB. Six other animals were diagnosed as asymptomatic latent carriers by positive RDB and 6 additional animals were only seropositive and were considered suspected carriers. A significant difference was found in the mean PCV between symptomatic and latent carriers with severe anemia observed only in the symptomatic animals. An anaphylactic-like reaction, fatal in one case, was observed in 2 camels diagnosed with severe trypanosome parasitemia immediately following treatment with melarsenoxide cysteamine. Furthermore, recurrence of infection was documented in one camel 4 months post treatment.  相似文献   

14.
Experimental Trypanosoma vivax infection of sheep produced a moderate leucopenia associated with a lymphopenia and eosinopenia. The total white blood cell counts of adult mice were not significantly depressed when inoculated with plasma from T. vivax-infected sheep. These observations suggested that the plasma of the infected sheep did not have a factor which could depress leucopoiesis in vivo.  相似文献   

15.
Two hundred and fifty-five biological samples (106 aborted foetal tissue samples and 149 blood samples from aborted sheep and goats) were collected from 188 animals during the lambing season from September 2009 to April 2010 from the Mafraq region of Jordan. The sampled animals belonged to 93 goat and sheep flocks that had cases of abortion. A total of 169 (66.3%) biological samples were collected from sheep and 86 (33.7%) from goats. Seventy-six (29.8%) biological samples (45 blood and 31 tissue samples) were positive for Toxoplasma gondii by PCR assay. The positive samples were obtained from 43 sheep and 23 goats. The overall toxoplasma-specific prevalence rate was 35.1% (66/188). Forty flocks (43%) had at least one T. gondii PCR-positive animal. The risk factors related to flock health status and farm management that are hypothesized to be associated with T. gondii PCR positivity were also assessed using multiple logistic regressions. The presence of cats (OR = 4.74), a large flock size (OR = 2.76) and the method of disposing the aborted foetuses (OR = 3.77) were all statistically significant (P < 0.05) risk factors that were positively associated with toxoplasma positivity in goat and sheep flocks.  相似文献   

16.
The newly described brittle tail syndrome causes weakening and breakage of the tail hair of horses. Extensive mycological and molecular studies showed that a novel fungus Equicapillimyces hongkongensis gen. nov., sp. nov. is the most likely cause of this syndrome. It is a septate branching hyaline mould which grows optimally at 30°C, requires nicotinic acid but is inhibited by cycloheximide, and specifically infects horse hair. Hyphae fill the core of infected hair shafts with short-necked structures resembling ascomata containing banana-shaped septate ascospore-like structures perforating the hair cortex from within. Compared to asymptomatic horses (n=31), horses with clinical signs of the syndrome (n=22) are significantly more likely to have positive E. hongkongensis gen. nov., sp. nov. smear (6.5% vs. 100%), culture (6.5% vs. 72.7%), and PCR (32.3% vs. 100%, P<0.001 for all). No other potential pathogens were found on bacteriological and mycological culture or PCR (for Trichophyton, Microsporum and Epidermophyton). Genotyping of pure E. hongkongensis gen. nov., sp. nov. isolates and their corresponding direct specimens by PCR and sequencing of the 18S rRNA, ITS1-5.8S-ITS2, 28S rRNA, beta-actin, beta-tubulin, and elongation factor 1 alpha showed that they are all identical but unique, and related distantly to fungi mostly in the class Sordariomycetes and the family Ophiostomataceae. Its geographical distribution, environmental or animal reservoirs are still unknown. Besides the ugly appearance of infected horse tails, this fungus may emerge as another equine pathogen if it affects the skin and hoof of horses.  相似文献   

17.
The causative agent of feline cytauxzoonosis was experimentally inoculated into 4 species of domestic farm animals, 9 species of laboratory animals, and 17 wildlife species. The inoculum consisted of freshly collected or deep-frozen blood and/or tissue homogenates from domestic cats euthanatized in extremis with experimentally transmitted feline cytauxzoonosis. A bobcat, Lynx rufus floridanus (Florida bobcat), developed cytauxzoonosis typical of the disease observed in domestic cats and died of the disease 2 weeks after inoculation. A persistent parasitemia, but no overt signs of illness, developed in another bobcat, Lynx rufus rufus (eastern bobcat). The sheep developed a low persistent parasitemia, but no clinical signs of illness. There was no clear evidence of cytauxzoonosis demonstrated by necropsy or histopathologic or blood smear examinations in all other species. Additionally, freshly collected blood and/or tissue homogenates from animals of various species, except bobcats, failed to produce evidence of cytauxzoonosis when subinoculated into domestic cats.  相似文献   

18.
The authors describe the results of a study on ticks and hemoparasitoses of cattle and small ruminants in the Senegalese north-sudanian area. For 15 months, 40 bovine, 40 sheep and 40 goats received a routine dipping treatment, aimed at the determination of the tick population dynamics together with an accurate localization of the preferential sites for the different species. The following parasites were collected from the animals: Hyalomma marginatum rufipes, H. truncatum, Rhipicephalus lunulatus, Rh. e. evertsi, Rh. sulcatus, Rh. senegalensis, Boophilus decoloratus. Joint studies were conducted on the hemoparasites using blood smear and splenectomy. Among bovine, Anaplasma marginale, Ehrlichia bovis, Theileria mutans, Th. velifera, Trypanosoma congolense, T. brucei and microfilariae from Setaria labiatopapillosa were observed. Babesia bigemina was observed after a splenectomy. In small ruminants, the detected infections are brought about by A. ovis, Th. ovis and T. vivax. Hematocrite value of apparently healthy animals are studied as well as the seasonal variation of this hematological factor.  相似文献   

19.
A 2-year-old East Friesian sheep imported from Australia exhibited severe anemia after contagious pustular dermatitis in Hokkaido, Japan. Hemoplasma infection was confirmed in blood smears. Both Mycoplasma ovis and 'Candidatus Mycoplasma haemovis' were detected by PCR and sequence analyses. In the epidemiological analysis, dual pathogens were detected in 6 of 12 (50.0%) sheep imported from Australia with the infected ewe at the same time, 1 of 5 (20.0%) sheep introduced from a domestic farm in Hokkaido, and in 1 of 16 (6.3%) sheep from an epidemiologically unrelated ranch. It is the first clinical case of sheep to confirm coinfection of these pathogens in Japan.  相似文献   

20.
Malignant catarrhal fever (MCF. corrizza contagiosa) is an invariably fatal communicable disease in cattle, whose causative agent is the ovine herpes virus-2, or the alcelaphine herpes virus-1. In one feed-lot family farm, 34 calves out of 100 became ill at the rate of one to four calves per week, and all of them subsequently died over a period of 4 months. Most of the initial cases were manifested clinically as the head and eye form, but most of the entire clinical spectrum of forms (the respiratory, intestinal and nervous forms) characteristic for MCF were observed as this epidemic progressed. Very few calves died without showing any specific signs of MCF. Pathological examinations revealed characteristic obliterative arteriovasculitis in the brain of calves with nervous signs, typical of MCF. Polymerase chain reaction (PCR) testing revealed 100% homology between the 238 bp hemi-nested PCR fragment and the ovine herpes virus-2 sequences. Based on the clinical signs, epidemiological data, pathological, and histopathological findings, and the PCR results, it was concluded that MCF occurred on the farm. The fact that sheep and goats were housed in close proximity on the same farm reinforced this diagnosis.  相似文献   

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