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1.
We evaluated the efficacy of buparvaquone in eliminating Babesia equi of European origin in carrier horses and in experimentally infected splenectomized ponies. When administered at the rate of 2.5 mg/kg of body weight, IM, 4 times at 96-hour intervals, buparvaquone was effective in eliminating B equi carrier infection in 1 horse. Such results could not be repeated at the same dosage or at 3.5 or 5 mg/kg, IM. Buparvaquone given at the rate of 4 to 6 mg/kg IV and/or IM was therapeutically effective in 4 of 5 acute B equi infections in splenectomized ponies. The treated ponies became carriers.  相似文献   

2.
Equine humoral immune response to Rhodococcus (Corynebacterium) equi   总被引：7，自引：0，他引：7  
An enzyme-linked immunosorbent assay was developed to test equine serum for the presence of antibodies to Rhodococcus (Corynebacterium) equi. Experimental ponies had no detectable antibody to R equi before exposure to the bacterium. After experimental inoculation, animals in groups that received live R equi subcutaneously or intranasally/intratracheally developed high titers to R equi. Noninoculated controls remained seronegative. Serum was also collected from horses of various ages that were naturally exposed to R equi. There was a wide range of anti-R equi titers in these horses. Because experimentally infected horses seroconverted when some naturally infected foals did not seroconvert, the function of antibody in resistance to R equi infection remains unknown.  相似文献   

3.
Babesia equi and Babesia caballi are tick-borne haemoparasites that may cause babesiosis of Equidae. In southern Europe B. equi is enzootic and infections may occur asymptomatically and more frequently than those due to B. caballi. Complement fixation test (CFT) is the official serological test for the diagnosis of equine babesiosis, but it has low sensitivity during early and latent stages of the disease. With the aim of developing more sensitive and rapid direct diagnostic alternatives, PCR systems that amplified DNA targets of 664 or 659 bp regions of the 16S rRNA genes were designed and demonstrated to specifically detect the genomes of B. equi and B. caballi, respectively. An approximated parasitaemia of 0.000083% was detected by the PCR system for B. equi compared with reported limits of 0.001% for microscopic examination of stained blood smears, and up to 0.00025% for DNA probes. Although the sensitivity of the PCR system for B. caballi could not be estimated, samples with microscopically undetectable parasitaemia as well as those with 0.017% parasitised red blood cells were detected. DNA extracts of blood collected with EDTA as an anticoagulant from 23 horses from Portugal were tested with both PCR systems. Of these samples, 22 were positive for B. equi and 8 were positive for B. caballi with PCR tests and intraerythrocytic parasites were seen in all samples. Antibodies against both parasites were not detected by CFT in several cases, but in these cases the presence of either or both parasites was apparent by PCR tests. The PCR systems may be useful in the diagnosis of equine babesiosis covering a wider range of clinical disease, as useful adjuncts to serological, microscopic, and cultural methods, especially for the import and export testing of horses.  相似文献   

4.
Heartwater is a tick borne disease that affects ruminants and wild animals in Africa south of the Sahara. It is caused by Ehrlichia ruminantium and transmitted by the tick Amblyomma hebraeum. The protocols currently used to detect heartwater take several days to complete. Here, we describe the development of a pCS20 quantitative real-time PCR TaqMan probe assay to detect E. ruminantium in livestock blood and ticks from the field. The assay is based on the conserved pCS20 gene region of E. ruminantium that contains two overlapping genes, rnc and ctaG [Collins, N.E., Liebenberg, J., De Villiers, E.P., Brayton, K.A., Louw, E., Pretorius, A., Faber, F.E., Van Heerden, H., Josemans, A., Van Kleef, M., Steyn, H.C., Van Strijp, M.F., Zweygarth, E., Jongejan, F., Maillard, J.C., Berthier, D., Botha, M., Joubert, F., Corton, C.H., Thomson, N.R., Allsopp, M.T., Allsopp, B.A., 2005. The genome of the heartwater agent Ehrlichia ruminantium contains multiple tandem repeats of actively variable copy number. PNAS 102, 838-843]. The pCS20 quantitative real-time PCR TaqMan probe was compared to the currently used pCS20 PCR and PCR/(32)P-probe test with regards to sensitivity, specificity and the ability to detect DNA in field samples and in blood from experimentally infected sheep. This investigation showed that the pCS20 quantitative real-time PCR TaqMan probe was the most sensitive assay detecting seven copies of DNA/mul of cell culture. All three assays, however, cross react with Ehrlichia canis and Ehrlichia chaffeensis. The pCS20 real-time PCR detected significantly more positive field samples. Both the PCR and pCS20 real-time PCR could only detect E. ruminantium parasites in the blood of experimentally infected sheep during the febrile reaction. The PCR/(32)P-probe assay, however, detected the parasite DNA 1 day before and during the febrile reaction. Thus, because this new quantitative pCS20 real-time PCR TaqMan probe assay was the most sensitive and can be performed within 2h it is an effective assay for epidemiological surveillance and monitoring of infected animals.  相似文献   

5.
Hobo S  Niwa H  Anzai T 《The Veterinary record》2006,159(19):629-632
The reactivity of synthesised peptide sets for the M-like proteins SeM and SzPSe with sera from horses infected with Streptococcus equi or Streptococcus zooepidemicus, or control horses, was investigated by an ELISA. Seventeen horses were infected experimentally with S equi or S zooepidemicus, convalescent sera were obtained from 25 horses and control sera were obtained from 1945 horses. The serum antibody responses of individual horses to the peptide sets were highly variable. Some of the peptide sets for SeM reacted strongly with the sera from the horses infected experimentally with S equi, but also reacted with sera from some of the horses infected experimentally with S zooepidemicus. However, the proline-glutamic acid-proline-lysine (PEPK) repeats peptide set, synthesised from the PEPK repeats areas of SzPSe, reacted most strongly with the sera from the horses infected experimentally with S equi and the horses convalescing from strangles, and reacted only minimally with the sera from the horses infected experimentally with S zooepidemicus and the control horses.  相似文献   

6.
Twenty blood samples of zebras (Equus zebra zebra) from the Karoo National Park and the Bontebok National Park in South Africa, all seropositive for Theileria equi, were subjected to in vitro culture to identify carrier animals and to isolate the parasites. Sixteen animals had a detectable parasitaemia in Giemsa-stained blood smears examined before culture initiation, the remaining four animals were identified as T. equi carriers by in vitro culture. Cultures were initiated either in an oxygen-reduced gas mixture or in a 5% CO2-in-air atmosphere. Out of the 20 blood samples, 12 cultures of T. equi and two cultures of T. equi mixed with Babesia caballi were established. None of the four animals seropositive for B. caballi could be identified as carrier animals, whereas two seronegative samples became culture-positive for B. caballi.  相似文献   

7.
A highly specific and sensitive competitive enzyme-linked immunosorbent assay for detection of specific antibody to Babesia equi in serum from equids was validated for use in Morocco. The assay is based on the specific inhibition of binding of a monoclonal antibody to a conserved epitope within a recombinant parasite peptide by serum from infected animals. The assay was compared to an established indirect immunofluorescence assay, with a concordance of 91%. The assay was used to determine seroprevalence for B. equi infections in donkeys and horses throughout Morocco. A total of 578 sera (163 horses and 415 donkeys) from 6 locations representing different bioclimatic regions were assayed. An analysis of variance, indicated no significant effect of location; however, donkeys were significantly more likely than horses to be seropositive. Management conditions contribute to greater tick infestations and thus Babesia exposure in donkeys than in horses.  相似文献   

8.
The prevalence of Theileria equi and Babesia caballi infections in the north-eastern Free State Province of South Africa was determined by examination of thin and thick Giemsa-stained blood smears, IFAT and PCR. No parasites were detected by microscopy from any blood samples collected at five study sites, Qwaqwa, Kestell, Harrismith, Vrede and Warden. Of the tested serum samples, 28/29 (96.5%), 20/21 (95.2%) and 42/42 (100%) were positive by IFAT for T. equi infections in Harrismith, Kestell and Qwaqwa, respectively, and 5/29 (17.2%), 13/21 (61.9%) and 30/42 (71.4%) were sero-positive for B. caballi infections in Harrismith, Kestell and Qwaqwa, respectively. All DNA samples from the study sites were negative for B. caballi infections by PCR, but five samples, two from each of Kestell and Warden and one from Vrede, were PCR positive for T. equi infections. The high prevalence of antibodies against T. equi and B. caballi in the sampled horses indicates that the animals had been exposed to T. equi and B. caballi infections but the absence of parasitaemia and very low number of positive PCR samples, however, imply that T. equi and B. caballi are endemically stable in the north-eastern Free State Province.  相似文献   

9.
Blood and serum samples were taken from 481 horses, from a stud farm or a racecourse, and tested by microscopic examination of blood smears and cELISA for Theileria equi (T. equi) and Babesia caballi (B. caballi) infections. At the time of sampling, animals were also examined for tick infestations and clinical disease, which were not observed in any of the sampled horses. During the microscopic examination of thin blood smears, parasites were detected in the three horses from the racecourse. Overall seroprevalence of infection was detected as 18.50% (89 of 481 horses) by cELISA, with T. equi being significantly more prevalent than B. caballi. Of the 481 blood samples, 78 (16.21%) were serologically positive for T. equi and 4 (0.83%) were serologically positive for B. caballi. In addition, 7 (1.46%) samples were positive for both T. equi and B. caballi antibodies. Seropositivity rates in the racecourse horses were higher than those determined in the stud farm horses. The rates for T. equi, B. caballi and both species were 13.39, 0.52 and 0% in the horses from the stud farm and 27, 2 and 7% in the racecourse horses, respectively. These results indicate that equine piroplasmosis is more common in racehorses than studhorses and therefore it might be a serious concern in horses that participate to international races.  相似文献   

10.
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   

11.
Equine piroplasms include two tick-borne protozoan parasites, Babesia caballi and Theileria equi. Although no clinical equine piroplasmosis has been reported in the Republic of Korea, the possible existence of the disease has been proposed due to a nationwide distribution of the vector ticks. To determine if the antibodies against B. caballi and T. equi were present, 184 sera of horses (Equus caballus) raised in the Republic of Korea from 2007 to 2010 were assessed using cELISA kits. Two (1.1%) out of 184 sera were positive for T. equi, but none were seropositive for B. caballi. Both samples tested positive came from one region (Gyeonggi province). The accuracy of the cELISA was confirmed by PCR using primers specific to the 18S rRNA of T. equi. This study presents for the first time horses infected by T. equi in the Republic of Korea. Since the infection of T. equi occurred in horses raised in the Republic of Korea, further studies with continuous monitoring of the vector ticks for equine piroplasms and appropriate control programs need to be established.  相似文献   

12.
The therapeutic efficacies of imidocarb and parvaquone were tested against Babesia equi of European origin in carrier horses and for induced acute infections in splenectomized ponies. Imidocarb, at a dosage of 4 mg/kg of body weight, given IM at 72-hour intervals 4 times, was ineffective in eliminating B equi-carrier infection in 9 mature geldings. A single IM administration of 4 mg/kg was not therapeutic in acutely infected splenectomized ponies. When given at 3 different dosages and treatment schedules, parvaquone was ineffective in clearing carrier infection. Parvaquone given IM once at a dosage of 20 mg/kg was effective for acute B equi infections in splenectomized ponies; parasitemia began to decrease within 24 hours after treatment. Infections were not eliminated however, and within 4 weeks, secondary parasitemia and anemia developed. Of 4 ponies, 3 died of acute piroplasmosis.  相似文献   

13.
We evaluated the efficacy of buparvaquone in eliminating infection with Babesia equi of European origin in carrier horses and in splenectomized horses with experimentally induced acute infection. When administered at the rate of 5 mg/kg of body weight, IV, 4 times at 48-hour intervals, buparvaquone prompted rapid abatement of parasitemia. However, secondary and tertiary recrudescent parasitemias invariably returned with establishment of the carrier state. Buparvaquone, at the dosage evaluated, had transitory therapeutic efficacy against acute B equi infection in splenectomized horses, but was unable alone to clear carrier infection.  相似文献   

14.
We describe a nested polymerase chain reaction (PCR) for the detection of Babesia equi in equine infected erythrocytes using oligonucleotides designed on the published sequence of a B. equi merozoite antigen gene (ema-1). A 102bp DNA fragment is specifically amplified from B. equi but not from Babesia caballi, Babesia bovis or Babesia bigemina DNA. In a mock infection we were able to detect down to six infected cells in 10(8) equine erythrocytes or to detect the parasite in blood with an equivalent parasitemia of 0.000006%. Furthermore, gene polymorphism was found by performing a PCR-RFLP (PCR combined with restriction fragment length polymorphism) on both the 102bp and the entire ema-1 gene DNA amplified from two B. equi isolates, Florida (USA) and Pelotas (Southern Brazil) isolates. The polymorphism was confirmed by sequencing the entire ema-1 gene from the B. equi isolate Pelotas. Our results demonstrate that the ema-1 based nested PCR is a valuable technique for routine detection of B. equi in chronically infected horses. It may be used for epidemiological and phylogenetic studies of the parasite as well as monitoring B. equi infected horses in chemotherapeutic trials.  相似文献   

15.
Hobo S  Niwa H  Anzai T 《The Veterinary record》2008,162(15):471-474
The reactivity of the proline-glutamic acid-proline-lysine (PEPK) repetition peptide antigen in 3176 serum samples was investigated to evaluate its utility as an antigen for the serological diagnosis of strangles. The reactivity of the sera of horses infected with Streptococcus equi subspecies equi was high when the peptide had several PEPK repetitions. However, as the number of PEPK repetitions increased, the reactivity of the antigen with the sera of horses infected with Streptococcus equi subspecies zooepidemicus also increased. In horses infected experimentally with S equi, the reactivity of the PEPK antigen with five repetitions increased one week after inoculation and continued to increase during the following four weeks. The optical density (OD) values of test sera from horses infected experimentally with S equi and sera from horses that had recovered from strangles were high. The od values of sera from horses that had recovered from an experimental infection with S zooepidemicus and of sera from healthy horses were comparatively low.  相似文献   

16.
We developed a TaqMan real-time polymerase chain reaction (PCR) assay for the quantitative detection of Theileria equi from the in vitro-cultured parasite and field blood samples collected from horses living in Ghana and Brazil. The detection limit for the assay was determined to be 1.5 parasites/microl per sample, and the quantitative capacity was demonstrated using the in vitro-cultured parasite. For field applications, the real-time PCR assay was compared to a previously established nested PCR assay used as the gold standard for the real-time PCR assay. Of 65 field blood samples, 46 samples were T. equi-positive in the nested PCR assay, while the real-time PCR assay also detected the parasite in all 46 of the nested PCR-positive samples but did not detect T. equi in the remaining 19 negative blood samples. This quantitative real-time PCR assay provides a valuable tool for fast laboratory diagnostic assessment of T. equi infection in horses.  相似文献   

17.
马泰勒虫病PCR检测方法的建立和应用   总被引：2，自引：1，他引：1  
为寻求一种快速、有效的马泰勒虫 (Theileria equi,T.equi) PCR检测方法。基于马泰勒虫18S rRNA基因序列,在其V4高变区设计特异性引物Te-18F、Te-18R,通过PCR技术获得了531 bp的核酸片段。用该引物对马泰勒虫、马泰勒虫和驽巴贝斯虫混合样本、驽巴贝斯虫、尤氏泰勒虫、中华泰勒虫、环形泰勒虫、绵羊泰勒虫、吕氏泰勒虫和瑟氏泰勒虫基因组模板进行特异性试验。同时对马泰勒虫基因组模板进行不同浓度稀释后扩增,以便于确定试验的敏感性。用本试验建立的方法与常规显微镜镜检方法对45份马属动物血样进行检测。特异性试验显示,在被检测的9个样本中,只有马泰勒虫及马泰勒虫和驽巴贝斯虫混合模板中扩增出了符合大小的特异核酸片段。驽巴贝斯虫、尤氏泰勒虫、中华泰勒虫、环形泰勒虫、绵羊泰勒虫、吕氏泰勒虫和瑟氏泰勒虫的扩增结果均为阴性。灵敏度试验结果表明,PCR对马泰勒虫的扩增效率可达到10-13。对本试验建立的PCR检测马泰勒虫方法评估结果显示,PCR对马泰勒虫的检出率为17.78%(8/45),显微镜镜检结果只有8.89%(4/45)两者的符合率为100%。本试验建立的马泰勒虫PCR检测方法不失,为一种好的检测方法。  相似文献   

18.
The sensitivity and specificity of the complement fixation (CF) test for the diagnosis of Babesia infections in equines was assessed, using the indirect fluorescent antibody (IFA) test as a reference. Antibodies were first detected between 11 and 20 days post infection (dpi) in the CF test and between 7 and 14 dpi in the IFA test in ponies infected experimentally with B. equi (USDA strain). The CF test became negative in four of five ponies 63-174 dpi although B. equi was demonstrated microscopically in two of these four ponies up to 364 and 455 dpi. The IFA test remained positive up to 476 dpi (end of the examination period). Ponies infected experimentally with B. caballi (USDA strain) showed positive reactions in the CF test at first between 13 and 15 dpi and in the IFA test 10 or 11 dpi. The CF test became negative in two of three ponies 80 and 140 dpi, whereas the IFA test remained positive up to 190 dpi (end of the examination period). Cross-reactions of sera with heterologous antigens occurred at dilutions of 1/5 in the CF test and up to 1/20 in the IFA test. A total of 3944 CF tests was performed on 3765 horses from various European countries during 1980-1984. Sera that gave positive or trace CF reactions were retested in the IFA test. All 123 CF-positive sera were also IFA-positive and 26 of 31 sera (B. equi) and 11 of 32 sera (B. caballi) showing CF trace reactions were positive in the IFA test. Sera of two CF-negative horses were positive in the IFA test (B. equi); one of these horses was also positive upon microscopic examination. In seven of 21 horses repeatedly examined over longer periods the IFA titers (B. equi) persisted for up to 454 days longer than the CF titers. Sera of horses from highly endemic areas gave the following reactions: Sudan, 62 of 91 sera CF- and 86 of 91 IFA-positive; Zaire, 58 of 75 sera CF- and 72 of 75 IFA-positive; Columbia, 51 of 56 sera CF- and 56 of 56 IFA-positive; Brazil, 17 of 25 sera CF- and 21 of 25 IFA-positive. Only B. equi infections were demonstrated in Zaire. The combined use of the CF and IFA tests is recommended for safe identification of equine Babesia infections.  相似文献   

19.
Two enzyme-linked immunosorbent assays (ELISA) with recombinant protein as antigens were evaluated by comparison with the indirect fluorescent antibody tests (IFAT) for the detection of specific antibodies to Babesia caballi and Babesia equi, respectively in 380 sera from experimentally infected, uninfected, and field horses. The high concordances of 92.4% (351/380) and 98.2% (373/380) between ELISA and IFAT for B. caballi and B. equi, respectively suggest that ELISA, especially for B. equi infection, could be alternative to the corresponding IFAT for serodiagnoses of equine piroplasmosis, although some improvements are required in ELISA for B. caballi.  相似文献   

20.
根据驽巴贝斯虫(Babesia caballi)18S rRNA基因序列设计1对特异性引物,扩增出452 bp核苷酸片段,建立了检测驽巴贝斯虫病的PCR方法。敏感性试验结果表明,该方法最低能检出0.01 fg/μL驽巴贝斯虫DNA模板。特异性试验结果显示,在被检测的6个巴贝斯虫株中,仅驽巴贝斯虫株能扩增出特异性片段,马泰勒虫、双芽巴贝斯虫、莫氏巴贝斯虫、卵形巴贝斯虫、大巴贝斯虫的扩增结果均为阴性。对45份马属动物血样进行检测,本研究建立的PCR方法测得驽巴贝斯虫病的阳性率为26.67%(12/45),与显微镜检测方法进行了比较,结果显示PCR检测方法可显著提高驽巴贝斯虫的检出率。  相似文献   

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