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1.
Low larkspur (Delphinium nuttallianum Pritz.) poisoning causes serious economic loss to livestock producers that graze cattle on foothill and mountain ranges in western North America. In general, all Delphinium spp. are five times less toxic to sheep than to cattle. Because low larkspurs are less toxic to sheep than cattle, grazing sheep before cattle on rangelands with dense populations of low larkspur can reduce larkspur density and risk of poisoning to grazing cattle. All previous published work on sheep and larkspur interactions has involved tall larkspurs. This series of studies was conducted to determine if sheep would consume sufficient low larkspur to reduce subsequent risk to cattle. Four summer trials were conducted in Collbran, Colorado, and Soda Springs, Idaho on pastures with dense (> 9 plants · m?2) low larkspur populations. In all trials, sheep ate very little low larkspur (< 0.5% of bites). During one final trial using high sheep density (two sheep · 0.015 ha?1 for 9 d), sheep consumed little low larkspur, but animals appeared to trample much of the low larkspur. Toxic alkaloid concentrations in low larkspur ranged from 1.1 mg · g?1 to 1.6 mg · g?1 in all trials. The use of sheep to graze low larkspurs to reduce subsequent consumption by grazing cattle does not appear to be a viable option.  相似文献   

2.
In addition to Aelurostrongylus abstrusus (Strongylida: Angiostrongylidae), referred to as the feline lungworm, Troglostrongylus brevior (Strongylida: Crenosomatidae) has recently been identified as an agent of bronco-pulmonary infestations in cats. These two parasites have a similar biology, share ecological niches, potentially co-infesting cats, but are difficult to be differentiated due to the morphological similarities of their first-stage larvae (L1). This paper describes a molecular tool, based on single-step duplex polymerase chain reaction (duplex-PCR) on the ribosomal internal transcribed spacer 2 region (ITS-2) for the simultaneous detection and differentiation of T. brevior and A. abstrusus. L1 of both species were collected from faecal samples, morphologically identified, and single larval specimens isolated. An aliquot of faeces was used as a test sample for a case of mixed natural infestation. The duplex-PCR was performed using species-specific forward primer sets for the ITS-2 region (i.e., A. abstrusus: 220 bp; T. brevior: 370 bp). The detection limit of the molecular assay was also assessed by serial dilutions of DNA from single larvae of both species (from ～4.0 to 4.0 × 10?5 μg/μl). The duplex-PCR carried out on individual DNA samples was able to detect as low as 5.2 × 10?3 μg/μl of DNA for A. abstrusus, 4.9 × 10?3 μg/μl for T. brevior, and as low as 4.0 × 10?3 μg/μl for samples containing both species. Species-specific bands of the expected sizes and two bands were simultaneously amplified from the faecal sample containing both species. The phylogenetic analyses of the ITS-2 sequences here examined and those available for other metastrongyloids were concordant in clustering them with those of other Troglostrongylus brevior and A. abstrusus sequences available in GenBank database. This molecular approach proved to be effective and highly sensitive for the simultaneous detection of the two lungworms species and it might be used for molecular epidemiological studies and for monitoring therapeutic protocols.  相似文献   

3.
本研究旨在阐明黄鳝胃瘤线虫湖南分离株的核糖体DNA(rDNA)内转录间隔区(ITS)及5.8 S rDNA序列的遗传变异情况,并用ITS序列重构胃瘤线虫与其它线虫的种群遗传关系.利用聚合酶链反应(PCR)扩增胃瘤线虫rDNA的ITS-1、5.8S及ITS-2片段,将PCR扩增出的片段纯化后克隆至pGEM-T Easy载体,重组质粒通过菌落PCR鉴定后,对阳性菌落进行序列测定并进行序列分析.结果显示所获得的胃瘤线虫ITS及5.8 S rDNA序列总长存在一定差异(922～927 bp),其中包含部分的18S、28 S及全部的ITS-1 (350～351 bp)、5.8S(102 bp)及ITS-2 (340～344 bp)序列.本研究系国内首次报道胃瘤线虫的ITS序列,其结果为黄鳝胃瘤线虫的分类鉴定以及进一步的分子流行病学调查和群体遗传研究奠定了基础.  相似文献   

4.
《Veterinary parasitology》2015,207(3-4):335-341
Trypanosoma theileri is a hemoprotozoan parasite that infects various ruminant species. We investigated the epidemiology of this parasite among cattle and water buffalo populations bred in Sri Lanka, using a diagnostic PCR assay based on the cathepsin L-like protein (CATL) gene. Blood DNA samples sourced from cattle (n = 316) and water buffaloes (n = 320) bred in different geographical areas of Sri Lanka were PCR screened for T. theileri. Parasite DNA was detected in cattle and water buffaloes alike in all the sampling locations. The overall T. theileri-positive rate was higher in water buffaloes (15.9%) than in cattle (7.6%). Subsequently, PCR amplicons were sequenced and the partial CATL sequences were phylogenetically analyzed. The identity values for the CATL gene were 89.6–99.7% among the cattle-derived sequences, compared with values of 90.7–100% for the buffalo-derived sequences. However, the cattle-derived sequences shared 88.2–100% identity values with those from buffaloes. In the phylogenetic tree, the Sri Lankan CATL gene sequences fell into two major clades (TthI and TthII), both of which contain CATL sequences from several other countries. Although most of the CATL sequences from Sri Lankan cattle and buffaloes clustered independently, two buffalo-derived sequences were observed to be closely related to those of the Sri Lankan cattle. Furthermore, a Sri Lankan buffalo sequence clustered with CATL gene sequences from Brazilian buffalo and Thai cattle. In addition to reporting the first PCR-based survey of T. theileri among Sri Lankan-bred cattle and water buffaloes, the present study found that some of the CATL gene fragments sourced from water buffaloes shared similarity with those determined from cattle in this country.  相似文献   

5.
利用聚合酶链反应（PCR）扩增蛇蛔虫rDNA的ITS-1、5.8S及ITS-2片段,将PCR扩增出的片段纯化后克隆至pGEM-T Easy载体,重组质粒通过菌落PCR鉴定后,对阳性菌落进行序列测定并进行序列分析。结果显示,所获得的蛇蛔虫ITS及5.8SrDNA序列总长为846bp,包含部分的18S、28S及全部的ITS-1、5.8S及ITS-2序列。本研究系国际上首次报道蛇蛔虫的ITS序列,从而为蛇蛔虫的分类鉴定以及进一步的分子流行病学调查奠定了基础。  相似文献   

6.
Horse flies can mechanically transmit Besnoitia besnoiti, the agent of bovine besnoitiosis. Although previously limited to enzootic areas, especially the French Pyrenees Mountains, bovine besnoitiosis is now considered a re-emerging disease in western Europe. To improve understanding of the role of horse flies as mechanical vectors, this study investigated their blood-feeding ecology in the eastern French Pyrenees, in two high-altitude summer pastures whose main domestic ungulates were cattle, and in a wildlife park with native fauna. Species-specific PCR assays were conducted to identify the sources of blood meals: wild boar, horse, cattle (or bison), sheep (or mouflon), goat, red deer, roe deer and izard (or Pyrenean chamois). In La Mouline pasture, tabanids (N = 20) fed on red deer (70%) and cattle (30%). In Mantet pasture, tabanids (N = 24) fed on cattle (52%), red deer (20%), wild boar (16%), horse (8%) and sheep (4%). In the wildlife park, Tabanus bromius (N = 32), the most abundant species collected, fed on red deer (85%), bison (9%) and wild boar (6%). Despite relatively high densities in both the pastures and in the wildlife park, small wild ungulates (izard, mouflon and roe deer) were not detected as a source of blood meals. Only two mixed blood meals were identified in two specimens of T. bromius: cattle/horse for the specimen collected in the pastures, and bison/wild boar for the specimen collected in the wildlife park. Our findings showed that tabanids display a level of opportunistic feeding behaviour, in addition to a preference for red deer, the latter being particularly true for Philipomyia aprica, the most abundant species collected in the pastures.  相似文献   

7.
Mini- and microsatellite sequences have proven to be excellent tools for the differentiation of strains and populations in several protozoan parasites due to their high variability. In the present work we have searched the genome of the tick-transmitted bovine hemoprotozoon Babesia bovis for tandem repeats (TRs) that could be useful for a multilocus typing system. Hundred and nineteen sequences were shortlisted and tested in five common B. bovis reference isolates originating from distinct geographic locations of North and South America: Texas, USA (T2Bo), Mexico (RAD and Mo7), and Santa Fe and Salta, Argentina (R1A and S2P, respectively). Satellite sequences were PCR-amplified using specific primers, separated by polyacrylamide gel electrophoresis, visualized by silver staining and sized. Fourteen TR sequences could be reliably amplified in all isolates and displayed length polymorphism. All primers used were specific for B. bovis and did not amplify genomic DNA from the bovine host or from Babesia bigemina, the principal co-infecting bovine parasite in the Americas, allowing their future use in field surveys. The 14 satellite markers identified are distributed throughout the four chromosomes of B. bovis as follows: chromosome 1 (n = 3), chromosome 2 (n = 2), chromosome 3 (n = 5), and chromosome 4 (n = 4). Within the five B. bovis isolates we identified nine satellite marker loci with two alleles, three with three alleles, one with four and another with five alleles. In comparison to Theileria parva, a bovine hemoprotozoan that pertains to the same piroplasmida order and owns a genome of similar size, the number of polymorphic TRs and the average number of alleles per TR locus seem to be significantly reduced in the B. bovis genome. Furthermore, the ratio of micro- to minisatellites in both B. bovis and T. parva is considerably lower than in other eukaryotes, as confirmed by bioinformatic analysis. The multilocus genotype of the five B. bovis isolates was assessed and the genetic distance between each other determined followed by cluster analysis based on neighbor joining. The resulting phenogram showed that B. bovis isolates segregated into three clusters according to their geographic origin. The presented marker system is suitable to explore various parameters of B. bovis populations such as genetic diversity, infection dynamics and their structure under different epidemiological situations, which are of crucial importance for improved control strategies.  相似文献   

8.
The present study examined the relationship among individual Sarcoptes scabiei mites from 13 wild mammalian populations belonging to nine species in four European countries using the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) as genetic marker. The ITS-2 plus primer flanking 5.8S and 28S rDNA (ITS-2+) was amplified from individual mites by polymerase chain reaction (PCR) and the amplicons were sequenced directly. A total of 148 ITS-2+ sequences of 404 bp in length were obtained and 67 variable sites were identified (16.59%). UPGMA analyses did not show any geographical or host-specific clustering, and a similar outcome was obtained using population pairwise Fst statistics. These results demonstrated that ITS-2 rDNA does not appear to be suitable for examining genetic diversity among mite populations.  相似文献   

9.
A case of pyogranulomatous dermatitis, caused by Mycobacterium abscessus, an unusual opportunistic Mycobacterium spp., is described in a cat. Histopathological examination of the affected skin confirmed the diagnosis and Ziehl-Neelsen staining revealed acid-fast rods. A rapidly growing mycobacterium was found after culture on a Löwenstein–Jensen medium. Real-time polymerase chain reaction for the 16S rDNA (434 bp) sequence and the sequence of the rpoB gene (359 bp) revealed 99% and 100% matches, respectively, with M. abscessus. This is the first report of a feline infection caused by this organism in Europe.  相似文献   

10.
In this work the clinical evolution and the specific serum IgG and IgE antibody responses in sheep after primary (n = 10) and secondary (n = 4) experimental challenges with the mange mite Sarcoptes scabiei var. ovis were studied. The primary infection was characterized by the development of mange lesions in all sheep, a detection of live S. scabiei mites in 70% skin scrapings taken in week 10 post-challenge (PC), strongly raised and sustained specific IgG levels and a more moderate but continuous rise in specific IgE levels. Seroconversion was detected for IgG and IgE by ELISA in 90% and 60% of the sheep in week 8 PC, respectively. By Western-blotting (WB), ten IgG-reactive bands (36–120 kDa) and four IgE-reactive bands (90–180 kDa) were observed in week 8 PC. Following the secondary challenge the ewes developed a smaller area of mange lesion than that seen following primary challenge and live S. scabiei mites were not detected in skin scrapings collected in week 8 PC, suggesting that sheep had developed immunity to re-infection. Compared to primary infection, the specific IgG secondary antibody levels were transient, but in contrast there was an anamnestic IgE response, resulting in an elicitation of specific serum IgE levels in week 2 PC significantly higher than those demonstrated after primary infection. WB analysis revealed one additional IgG-reactive band (180 kDa) and no additional IgE-reactive bands. Determining the immunodiagnostic or vaccination value of the IgG-reactive antigens and IgE-reactive allergens detected requires further studies.  相似文献   

11.
The analysis of infection by Paramphistomidae trematodes was conducted in two agricultural regions with different knowledge on this parasitosis. Faecal and blood samples were collected from 374 cattle in Salto (NW Uruguay) where there is a lack of information about paramphistomosis. A total of 429 cattle from Galicia (NW Spain), an area with previous records of infection by gastric flukes, were sampled. Diagnostics of trematodosis was developed by using a copromicroscopic probe and an ELISA with excretory/secretory antigens collected from adult Calicophoron daubneyi (Paramphistomidae) specimens. Results were evaluated according intrinsic and extrinsic factors.In the Uruguay, the percentage of cattle passing Paramphistomidae-eggs by faeces was 7% (95% Confidence Interval 5, 10). A significantly higher prevalence of paramphistomosis in the Hereford × Angus cattle (OR = 3.5) was recorded, as observed for the oldest ruminants (>3.5 years). An overall seroprevalence of 29% (25, 34) was obtained by ELISA, with the highest values in the Friesians (OR = 3), the youngest bovines (<2.5 years) and dairy cattle (Friesians).Twenty-six percent (22, 30) of the cattle from Spain passed eggs by faeces, and cattle aged 2.5–7 years reached significant highest prevalences. By means of the ELISA, a percentage of 55 cattle (50, 59) had antibodies against the gastric fluke, and the highest seroprevalence was observed among the bovines under 6 years.It is concluded that paramphistomosis is on the increase in cattle from NW Spain, partly due to the absence of an effective treatment against the trematode. There is a need for reducing the risk of infection by Paramhistomidae spp. in cattle from Uruguay, especially by improving their management to avoid exposure to the gastric trematode. Further studies are in progress for identifying the species of Paramphistomidae affecting ruminants in Uruguay.  相似文献   

12.
斑马蛔虫ITS及5．8SrDNA的克隆及进化分析   总被引：1，自引：0，他引：1  
胡鹏辉 《动物检疫》2013,(12):62-65
研究从斑马体内分离的蛔虫的核糖体DNA内转录间隔区（ITS）及5．8SrDNA序列的遗传变异情况,并用ITS序列重构斑马蛔虫与其它蛔虫的种群遗传关系。利用聚合酶链反应（PCR）扩增斑马蛔虫rDNA的ITS-1、5．8S及ITS-2片段,将PCR扩增出的片段纯化后克隆至pGEM．TEasy载体,重组质粒通过菌落PCR鉴定后,对阳性菌落进行序列测定并进行序列分析。结果显示所获得的斑马蛔虫ITS及5．8SrDNA序列总长为892bp,包含部分的18S、28S及全部的ITS,1、5．8S及ITS．2序列。证实从斑马体内分离的蛔虫为马副蛔虫,从而为斑马蛔虫的分类鉴定以及进一步的分子流行病学调查奠定了基础。  相似文献   

13.
Infection with bluetongue virus serotype (BTV)-8 occurred in ruminants in 2006 in Central-Western Europe. The trans-placental passage of this virus has been demonstrated in naturally- and experimentally-infected cattle and in experimentally-infected sheep. Trans-placental transmission is potentially important in the ‘over-wintering’ of this virus and its subsequent impact on reproductive performance. This epidemiological study was carried out on a sheep flock in Belgium that had experienced a severe outbreak of BTV-8 infection, and where the seroprevalence had increased from 1.3% to 88% between January and November 2007. In total, 476 lambs and 26 aborted fetuses from 300 ewes, lambing at four distinct time periods, were investigated between November 2007 and May 2008.The following evidence suggested that BTV-8 infection occurred in utero: (1) positive PCR results from splenic tissue from aborted fetuses (n = 4); (2) fetal malformations suggestive of BTV infection (n = 10); (3) positive PCR results from red blood cells in-lambs (n = 7), and (4) the presence of antibody at birth in viable lambs prior to the intake of colostrum (n = 9). The evidence provided by this investigation strongly suggests that trans-placental BTV-8 infection occurs in naturally-infected sheep and the impact of infection on the reproductive performance of such a naïve flock was considerable, with up to 25% of ewes aborting and with flock fertility reduced by 50%. The contribution of in utero-infected lambs to the over-wintering of BTV appears limited.  相似文献   

14.
郝桂英  何学谦 《中国畜牧兽医》2015,42(12):3167-3172
应用保守引物BD1和BD2对7个鸡蛔虫凉山州分离株的核糖体DNA内转录间隔区(ITS)及5.8S rDNA序列进行PCR扩增和序列测定,并用ITS-1、ITS-2序列重构鸡蛔虫与其他蛔虫的系统发育关系。测序结果显示所获得的鸡蛔虫ITS及5.8S rDNA序列大小为974~989 bp,同源性为98.9%~100.0%。其中ITS-1、5.8S rDNA和ITS-2片段大小分别为473~481、157和337~359 bp,同源性分别为98.5%~100.0%、100.0% 和98.5%~100.0%。系统发育树显示所有鸡蛔虫分离株聚在同一分支,能与其他蛔虫相区别。研究结果表明,鸡蛔虫的ITS-1、ITS-2序列种内变异小,但种间差异大,故可作为分子标记用于鸡蛔虫的虫种鉴定,为鸡蛔虫的分子分类、分子流行病学调查和种群遗传的进一步研究奠定基础。  相似文献   

15.
Brucellosis is a highly contagious zoonotic infection affecting livestock and human beings. The disease has been reported worldwide except in few countries where it has been eradicated. The prevalence of brucellosis among cattle from 11 farms having a history of abortions was studied. A total of 481 samples comprising of blood, milk, vaginal swabs, vaginal discharges, placental tissues and fetal tissues were collected from 296 animals. Clinical samples were processed for the isolation of Brucella. Serum samples (n = 296) were tested by Rose Bengal Plate Test (RBPT) and indirect ELISA. A total of 90 (30.40%) and 123 (41.55%) samples were positive by RBPT and indirect ELISA, respectively. Also 27.02% samples were positive by both the tests. Brucella isolates (n = 8) were recovered from clinical samples using Brucella selective media. All the isolates demonstrated PCR amplification for the bcsp31 and IS711 genes. Amplification of Brucella abortus specific primer was demonstrated by all the isolates in AMOS PCR indicating isolates to be of either B. abortus biotype 1, 2 or 4. Risk factors for transmission of brucellosis among cattle population were studied by field surveys. It was observed that lack of awareness about brucellosis (OR = 8.739, P = 0.138) and inadequate floor space (OR = 0.278, P = 0.128) were crucial risk factors for transmission of bovine brucellosis.  相似文献   

16.
基于ITS序列的捻转血矛线虫系统进化分析   总被引：1，自引：1，他引：0  
为分析捻转血矛线虫ITS序列的变异与虫株特性之间的关系,对捻转血矛线虫不同药物抗性虫株(苯并咪唑类药物抗性虫株、伊维菌素抗性虫株、莫西菌素抗性虫株、药物敏感虫株)、不同宿主来源虫株(长颈鹿、牛、绵羊、山羊、牦牛)和不同地理位置(中国、美国、意大利、法国、也门、马来西亚、澳大利亚)的分离株,以及毛圆科的其他线虫的ITS序列进行了分析。结果发现捻转血矛线虫与毛圆科其他线虫的ITS-2基因的相似性高,基于该基因建立的系统进化树可以很好地区分毛圆科不同属的线虫;捻转血矛线虫的抗药性特点与其ITS-1基因的变异进化关系不大;不同地理位置的捻转血矛线虫分离株的ITS-2基因变异很小;从野生动物长颈鹿体内分离的捻转血矛线虫的ITS-1基因与家养反刍动物分离株的差异较明显。研究结果表明捻转血矛线虫ITS序列在种内相对保守,不同虫株间变异较小,在毛圆科线虫的分子分类中具有一定意义。  相似文献   

17.

Objective

To evaluate three volumes of lidocaine for spermatic cord block to perform castration in cattle.

Study design

Randomized blinded clinical study.

Animals

Thirty mixed-breed Nellore cattle, aged 28–40 months and weighing 395 ± 21 (352–452) kg [mean ± standard deviation (range)].

Methods

Cattle were restrained in a chute and allowed to stand without sedation. Three milliliters of 2% lidocaine without epinephrine were infiltrated subcutaneously at each site of scrotal incision in all animals. The animals were allocated to three groups of 10 animals each. Lidocaine 2% was injected into each spermatic cord using a volume of 2, 3 or 4 mL in groups A, B, or C, respectively. The total volumes of lidocaine used were 10, 12, and 14 mL in groups A, B, and C, respectively. The duration of surgery and the retraction of the testicle (scored as positive or negative according to retraction of the testicle) during the procedure were recorded. The data were statistically analyzed by one-way anova followed by Tukey’s and chi-square tests. Differences were considered significant when p < 0.05.

Results

The mean surgical time was shorter in group C than in groups A and B (p < 0.001). In groups A, B and C, 90%, 60% and 10% of the animals showed retraction of the testicle, respectively. Fewer animals retracted the spermatic cord in group C than in group A (p = 0.002) and B (p = 0.02).

Conclusions and clinical relevance

Optimal spermatic cord block was achieved by injection of 4 mL of 2% lidocaine 5 minutes before castration and following incisional infiltration of lidocaine, in adult cattle weighing about 400 kg.  相似文献   

18.
Rectal smears of calves, cows and young bulls, as well as cloacal smears of house sparrows (Passer domesticus), from farms at the villages of Šumice and Troskotovice, Czech Republic, were examined for E. coli resistant to 12 antimicrobials. The resistant isolates were tested for antimicrobial-resistance genes and integrons. Totals of 40% (n = 183), 3% (n = 95), 0% (n = 33), and 9% (n = 54) of Escherichia coli isolates from calves, cows, young bulls and house sparrows, respectively, were antimicrobial resistant. The following genes were identified in cattle E. coli isolates: tetA, tetB (isolates resistant to tetracycline), blaTEM (beta-lactams), strA, aadA (streptomycin), sul1, sul2 (sulphonamides), and cat, floR (chloramphenicol). Seven of 16 antimicrobial-resistant calf isolates from the Šumice farm possessed class 1 integrons with the aadA1 gene cassette integrated, 1 kb in size. On the Troskotovice farm, eight of 57 antimicrobial-resistant calf isolates possessed class 1 integrons. Integrons of 1.5 kb with the dhfr1- aadA1 gene cassette were found in four isolates, followed by a 1 kb integron with the aadA1 gene found in three isolates, and a 1.7 kb integron with the dhfr17-aadA5 gene cassette and the phenotype ASSuTSxtNaCipCCfG. The prevalence of resistant E. coli in calves compared to adult cattle was much higher and probably was influenced by oral antimicrobial usage in calves, feeding with milk and colostrum from treated cows, as well as mechanisms unrelated to antimicrobial drug selection. Although house sparrows lived together with the cattle and came into contact with cattle waste on the farm, they were not infected by resistant E. coli isolates with the same characteristics as those found in cattle.  相似文献   

19.
根据OenBank上已发表的环孢子虫（Cyclospora）rDNA序列设计并合成1对引物，利用PCR技术时首次在牛体内发现的形态学特征与人环孢子虫（Cyclospora cayetanensis）极为相似的牛源环孢子虫的ITS-1＋序列进行了扩增。将PCR扩增出的片段纯化后，克隆至pGEM—TEasy载体后进行序列测定，并利用NCBI在线BLAST程序对测序结果进行了同源性比较和序列分析。分析结果显示，扩增的ITS-1＋大小为865bp的片段，包含18S部分序列（371bp）、ITS-1全序列（385bp）和5．8S部分序列（109bp）。序列同源性分析表明，该牛源环抱子虫为艾美尔科原虫，但不同于目前已知的各种艾美尔科原虫，可能是一种新发现的原虫。  相似文献   

20.
Bovine besnoitiosis is an economically important disease in cattle caused by the protozoan parasite Besnoitia besnoiti, which occurs endemically in many countries of Africa and Asia and is spreading in Europe. Serological identification of subclinically infected cattle is important to avoid the introduction of infected animals into naive herds. Here we determine the sensitivity and specificity of the PrioCHECK® Besnoitia Ab, a serological test recently introduced into the European market. Analytical specificity was examined using sera from animals experimentally infected with parasites related to B. besnoiti (n = 27). Three animals experimentally infected with Neospora caninum or Toxoplasma gondii showed inconclusive reactions in the ELISA (percent positivity relative to the positive control [PP] 10% ≤ 20%) while all other sera reacted negative (PP < 10%). An estimate of the diagnostic specificity was obtained by analysing field sera from bovine herds without besnoitiosis but with abortion problems associated to N. caninum (n = 403). The analysis revealed a specificity of 94.3% or 96.8% depending on the applied cut-off (PP 10% or 20%, respectively). Sensitivity was assessed with sera from 110 animals of a herd in Germany where clinical bovine besnoitiosis was first diagnosed in September 2008. A positive serological reference standard was defined regarding sera from animals as reference positive, if these animals had tested positive in at least two of a panel of three other serological tests (two different B. besnoiti immunoblots and one immunofluorescence antibody test) on both of two sampling dates, November 2008 and April 2009. A diagnostic sensitivity of 91.8% or 75.5% was determined for sera collected in November 2008 and a sensitivity of 82.7% or 50% for sera collected in April 2009 (cut-off PP 10% or PP 20%, respectively). The marked drop in sensitivity from November 2008 to April 2009 was predominantly observed in reference-positive cattle without clinical signs. We conclude that PrioCHECK® Besnoitia Ab is a valuable diagnostic tool to detect clinically infected animals. Thus it may be used to support control measures, e.g., for the separation of infected animals from the remaining herd to avoid a further transmission of the infection within the herd.  相似文献   

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