Phylogenetic characterisation of bluetongue viruses from naturally-infected insects, cattle and sheep in Australia   总被引：1，自引：0，他引：1  

KA McCOLL  AR GOULD  LI PRITCHARD  L MEL VILLE†  G. BELLIS† 《Australian veterinary journal》1994,71(4):102-105

SUMMARY The polymerase chain reaction was used to detect the presence of blue-tongue virus (BTV) in a number of clinical and insect samples collected in the Northern Territory of Australia. Sequence analyses of the amplified BTV genes differentiated endemic Australian and exotic viruses. Two potential exotic BTV were detected as a result of PCR analyses of blood from sentinel animals and of the insect vector, Culicoides wadai. The detection of BTV in C wadai was the first direct demonstration of the presence of BTV in this potential vector. This new technology can significantly reduce the time taken for a diagnosis from a clinical sample and increase the amount of useful information obtained on a BTV isolate by using rapid sequencing techniques. Sequence data were used to differentiate between BTV20 isolated in 1975 and two isolates of the same serotype, isolated in 1992, and indicated that the latter were probably a recent incursion into Australia from Indonesia due to their greater VP3 sequence homology to the BTV9 (Java) than to Australian BTV isolates.  相似文献   

Estimation of seroprevalence of encephalomyocarditis in Dutch sow herds using the virus neutralization test     

Augustijn M  Elbers AR  Koenen F  Nielen M 《Tijdschrift voor diergeneeskunde》2006,131(2):40-44

Encephalomyocarditis virus (EMCV) has been found on pig farms worldwide and can cause myocarditis in young pigs and reproduction disorders in sows. So far, clinical signs of EMCV have not been reported in the Netherlands. The aim of this study was to estimate the seroprevalence of EMCV infection in Dutch sow herds. A total of 277 Dutch sow herds were randomly selected, from which 3237 serum samples were collected. These samples were tested for EMCV antibodies using the virus neutralization test (VN test). The apparent prevalence of EMCV antibodies was 9.3% in the total sow population, and the apparent herd prevalence was 58.8%. An exact determination of the prevalence of EMCV infections in the Dutch sow population was not possible because the characteristics of the VN test under field circumstances were not known. However, Dutch sow herds seem to be infected with EMCV because the distribution of positive blood samples in the tested sow population was significantly different from that expected if random false-positive reactions had occurred.  相似文献   

Transmission characteristics of low pathogenic avian influenza virus of H7N7 and H5N7 subtypes in layer chickens     

Gonzales JL  Elbers AR  Bouma A  Koch G  de Wit JJ  Stegeman JA 《Veterinary microbiology》2012,155(2-4):207-213

Low pathogenic avian influenza virus (LPAIv) infections of H5 and H7 subtypes in poultry are notifiable to the OIE, hence surveillance programmes are implemented. The rate at which LPAIv strains spread within a flock determines the prevalence of infected birds and the time it takes to reach that prevalence and, consequently, optimal sample size and sampling frequency. The aim of this study was to investigate the transmission characteristics of an H7N7 and an H5N7 LPAIv in layer chickens. Two transmission experiments were performed, which consisted of 30 (first experiment) and 20 (second experiment) pairs of conventional layers, respectively. At the start of the experiments, one chicken per pair was inoculated with LPAIv and the other chicken was contact-exposed. Occurrence of infection was monitored by regularly collecting tracheal and cloacal swab samples, which were examined for the presence of virus RNA by RT-PCR. The results of the test were used to estimate the transmission rate parameter (β), the infectious period (T) and the basic reproduction ratio (R(0)). In addition, egg production and virus shedding patterns were quantified. For the H7N7 virus, the β, T and R(0) estimates were 0.10 (95% confidence interval (CI): 0.04-0.18) day(-1), 7.1 (95% CI: 6.5-7.8) days and 0.7 (95% CI: 0.0-1.7), respectively. With the H5N7 virus, only a few inoculated chickens (5 out of 20) became infected and no transmission was observed. This study shows that transmission characteristics of LPAIv strains may vary considerably, which has to be taken into account when designing surveillance programmes.  相似文献   

Veterinary practice and occupational health     

A.R.W. Elbers  P.J. Blaauw  M. de Vries  P.J.M.M. van Gulick  O.L.M.J. Smithuis  R.P. Gerrits 《The Veterinary quarterly》2013,33(4):127-131

Summary

The prevalence of allergy, lung function disorders, and bronchial hyperreactivity was studied in 102 Dutch veterinarians, subdivided into five professional groups (predominantly working with either swine, cattle, poultry, companion animals, or as a non‐practitioner). The mean age of the participants was 43 years; 6 participants were females. Twenty‐two per cent of the participants were overweight, and relatively more non‐practitioners than practitioners were overweight. Approximately 23% of the vets reported complaints of prolonged fatigue. The data suggest a relationship between complaints of prolonged fatigue and a more than average number of daily working hours. Only a small proportion of vets were sensitized against several allergens. There were no significant differences in prevalence of distinct lung function disorders or bronchial hyperreactivity between professional groups. It is hypothesized that the respiratory complaints (chronic coughing, chronic phlegm production, stuffed nose, sneezing) reported by the vets predominantly working in swine and/or poultry practice could be caused by irritation and/or inflammation of the first part of the trachea‐bronchial tree that has no measurable and permanent consequences for changes in lung function or increased bronchial hyperreactivity. The results of a skin test against allergens and determination of allergen‐specific IgE in blood indicated that the respiratory complaints were probably not related to allergy against the panel of allergens tested.  相似文献   

A Bayesian meta-analysis of the effects of administering an intra-vaginal (CIDR) device in combination with other hormones on the reproductive performance of cycling,anoestrous and inseminated cows     

AR Rabiee  IJ Lean  MA Stevenson 《New Zealand veterinary journal》2013,61(6):384-393

AIMS: To evaluate the effectiveness of treatment programmes that included controlled internal drug-releasing (CIDR) devices containing progesterone (P4) in improving synchrony of oe- strus, and conception and pregnancy rates in cycling, anoestrous and inseminated dairy cows, using meta-analysis. To describe the difference in response between cycling and anoestrous cows to CIDR-based synchrony programmes.

METHODS: Scientific papers written in the English language between 1989 and 2002 that investigated the effects of treat- ment programmes including CIDR devices on reproductive per- formance in dairy heifers or lactating dairy cows were identified using a computerised literature search. The criteria for inclusion incorporated evidence that treatment allocation was completely randomised; the population studied was lactating dairy cows; and that data were available on submission, conception and pregnancy rates and their associated measures of variability. Re- productive outcomes from 25 synchrony trials (total n= 11,058 cows) were analysed. Summary measures of the effect of treat- ment on reproductive outcome were assessed using fixed- and random-effects Bayesian meta-analysis models.

RESULTS: Treatment programmes including a CIDR device increased the risk of submission in cycling cows (predicted Bayesian RR=2.86, 95% credible interval 1.46–5.67). Compared with controls, synchrony programmes including CIDR devices in cycling dairy cows had no effect on the risk of conception to first service post-treatment (predicted Bayesian RR=1.00, 95% credible interval=0.80-1.24). Compared with controls, synchrony programmes including CIDR devices had no effect on the risk of pregnancy throughout the mating period (pre- dicted Bayesian RR=1.02, 95% credible interval=0.89-1.17). In anoestrous cows, CIDR treatment had no effect on the risk of conception to first service post-treatment and no effect on the risk of pregnancy throughout the mating period, compared with anoestrous, untreated controls (predicted Bayesian RR=0.91 and 0.97, respectively; 95% credible interval=0.68–1.26 and 0.59-1.60, respectively).

CONCLUSION: The results of this meta-analysis showed that synchrony programmes using CIDR devices combined with other hormones reliably enhanced submission rates in lactat- ing dairy cows. The relatively small number of trials with data suitable for analysis and the heterogeneity of results at the indi- vidual trial level limited our ability to confirm either a beneficial or deleterious effect of treatment on conception or pregnancy rates. Further randomised, controlled trials to evaluate the ef- fectiveness of this form of reproductive therapy in commercial dairy farms are needed.  相似文献   

Epidemiology of bluetongue virus serotype 8 outbreaks in the Netherlands in 2006     

Elbers A  Backx A  van der Spek A  Ekker M  Leijs P  Steijn K  van Langen H  van Rijn P 《Tijdschrift voor diergeneeskunde》2008,133(6):222-229

In August 2006 a major epidemic of Bluetongue (BT) occurred in north-western Europe, affecting The Netherlands, Belgium, Germany, Luxemburg, and the north of France. It was caused by Br virus serotype 8 (BTV-8), a serotype previously unknown to the EU. Although clinical disease is usually restricted to sheep, this virus also caused clinical disease in a small proportion of cattle. The last clinical outbreak of BT in The Netherlands occurred mid-December 2006. The delay between observation of the first clinical signs by the owner and reporting of a clinically suspect BT situation to the veterinary authorities was approximately 2 weeks. BTV-8-associated clinical signs were more prominent in sheep than in cattle, and the relative frequency of specific clinical signs was different in cattle and sheep. Morbidity and mortality rates were significantly higher among sheep than among cattle, and a higher proportion of cattle than sheep recovered from clinical disease.  相似文献   

Prevalence,radiographic resolution and outcomes of slab fractures of the third and central tarsal bones in juvenile Thoroughbred horses     

CM Steel  VL Collins  SR Hance  AR Adkins  PL Hitchens 《Australian veterinary journal》2019,97(4):108-115

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Ultrathin films of a polyelectrolyte with layered architecture     

AR Esker  C Mengel  G Wegner 《Science (New York, N.Y.)》1998,280(5365):892-895

Posttransfer modification of preformed Langmuir-Blodgett films of poly(tert-butyl methacrylate) and poly(tert-butyl acrylate) by gaseous hydrochloric acid yields films with layered architecture of poly(methacrylic acid) and poly(acrylic acid), respectively. X-ray reflectivity and infrared spectroscopy confirm monolayer by monolayer transfer of the source polymers and their transformation to acid multilayer assemblies with retention of low surface roughnesses. The incorporation of cross-linking groups into the system offers the possibility for further chemical modification to produce ultrathin films of model networks desirable for bioadsorption studies and as hydrophilic spacing layers for tethered membranes.  相似文献   

Expression of MHC-I and -II in Uterine Tissue from Early Pregnant Bitches     

S Schäfer-Somi  HB Beceriklisoy  I Walter  S Sabitzer  D Klein  H Kanca  D Kaya  AR Agaoglu  H &#;zgür  S Aslan 《Reproduction in domestic animals》2009,44(S2):103-108

The aim of the study was to investigate the expression of major histocompatibility complex (MHC)-I and -II in uterine tissues from pregnant and non-pregnant bitches, taken at different time periods after mating. The pregnant bitches were ovariohysterectomized during the pre-implantation (group 1, n = 4), implantation (group 2, n = 7) and placentation stage (group 3, n = 7). Non-pregnant animals in diestrus served as controls (group 4, n = 7). The expression of MHC- I and -II in salpinx, apex, middle horn, corpus uteri and at implantation sites was investigated by immunohistochemistry as well as qualitative and quantitative RT-PCR; MHC-I mRNA was detected in all tissues and with quantitative RT-PCR, and no significant changes were detected until placentation. Immunohistologically, at the apex and corpus site, the average number of MHC-II positive cells increased from the pre-implantation to the post-implantation stage (apex: 1.54 ± 1.21 to 3.82 ± 2.93; corpus: 1.62 ± 1.9 to 5.04 ± 4.95; p < 0.05). The greatest numbers of MHC-II positive cells were observed at placentation sites (6.64 ± 5.9). In parallel, a marked increase in the relative mRNA expression of MHC-II in uterine tissues was assessed from the pre-implantation to the placentation stage (relative to Glycerinaldehyd-3-phosphate-Dehydrogenase (GAPDH): 6.9 ± 9.5, 8.4 ± 5.8, p > 0.05). Immunohistologically, in the salpinx, significantly greater numbers of MHC-II positive cells were found in the tissues of pregnant animals than in the control group (p < 0.05). It is proposed that the increase in MHC-II is pregnancy-related, even though the impact on maintenance of canine pregnancy is still unclear.  相似文献   

Morphological Examination of the Corpora Lutea from Pregnant Bitches Treated with Different Abortifacient Regimes     

N Martin  T Höftmann  E Politt  HO Hoppen  M Sohr  AR Günzel-Apel  A Einspanier 《Reproduction in domestic animals》2009,44(S2):185-189

Different abortifacient regimes in dogs were analysed for their effect on the pregnancy corpora lutea (CL), namely, prostaglandin F2a analogue cloprostenol (CLO) combined with dopamine agonist cabergoline (CAB), or progesterone (P4) receptor antagonist aglepristone (AGL). Ovaries were collected after 6-10 days of treatment during first trimester. The CL of the control-group showed strong expression of relaxin (RLX), its receptor RXFP1 and enzymes of steroid biosynthesis (HSD) with high peripheral P4-levels. Whereas RXL, RXFP1 and HSD were lowest expressed in the CLO/CAB-group with a massive degeneration of CL and their blood vessels combined with low peripheral P4-level. The AGL-group showed less extensive CL degeneration and more intensive staining of the examined factors than CLO/CAB. In summary, all examined factors are associated with normal luteal function and are useful tools to stage luteolysis. Although both treatments have the same abortive action, their sequence of events on the CL is different.  相似文献