首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
Porcine circovirus type 2 (PCV2) is considered as the causative agent of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs, where the virus is ubiquitous as evidenced by serological surveys. We present the results of the first nationwide sero-survey on the presence of PCV2 antibodies in European wild boars, and report the first PMWS case in a wild boar from Spain. Sera from 656 hunter harvested wild boars from 45 different geographical sites and 22 additional imported animals were analysed by means of an immunoperoxidase monolayer assay (IPMA). We also examined the tissues from 55 healthy and one diseased wild boars for the presence of PCV2 nucleic acid and PMWS lesions by in situ hybridisation and histopathology, respectively. Additionally, abundance estimates of wild boars and field interviews were carried out on 30 sampling sites. The prevalence of medium to high PCV2 serological titres among the examined wild boars was 47.89 +/- 1.9%. Seropositive wild boars appeared in all but one of the geographical regions analysed. Seroprevalence and titre of PCV2 antibodies were closely related to the management of the wild boar populations. Wild boars from intensively managed, farm-like populations had higher prevalence than wild boars living in more natural situations. The effect of wild boar abundance and management on PCV2 antibody prevalence was further evidenced by the high correlation existing between the relative abundance estimates of animals and the percentage of wild boars with medium to high levels of PCV2 antibodies. PCV2 nucleic acid was detected in the tissues of three wild boars. One of these was diagnosed as PMWS. The results, in addition to information on piglet mortalities, suggest a potential role of PMWS in piglet mortality in intensively managed wild boar populations.  相似文献   

2.
Porcine circovirus type 1 (PCV1) is considered to be a non-pathogenic virus detected in cell cultures, vaccines or products used for cell culture preparations, all of them of porcine origin. Serological evidence and genetic studies suggested that PCV1 was widespread in domestic pigs. The presence of PCV1 in wild boars in Germany was also described using serological methods. This paper reports the first detection of PCV1 in Hungarian wild boars. Samples were collected at slaughterhouses and processed for polymerase chain reactions. The complete genome of PCV1 detected in the samples was determined and compared with the available PCV1 sequences of the GenBank database. The genomes formed two distinct clusters with minimum differences, where the Hungarian wild boar PCV1 (WB-H8) grouped together with genomes originating from domestic swine from China and Australia and with a genome detected in a porcine pepsin product.  相似文献   

3.
Hepatitis E virus (HEV) is known as a causative agent of zoonosis and food poisoning. Pigs and some species of wild animals, including wild boar, are known to be a reservoir of HEV. In this study, we investigated the situation regarding HEV infection in wild boars in Ibaraki Prefecture, Japan. Serum, liver and feces samples from 68 animals were collected, and the presence or absence of HEV genomic RNA and HEV antibodies were analyzed. The viral genome was detected in samples from 7 (10.3%) animals, with all HEVs classified as genotype 3, subtype 3b. HEV antibodies were detected in samples from 28 (41%) animals. This report demonstrates for the first time the high prevalence of HEV infection in wild boars in Ibaraki Prefecture.  相似文献   

4.
In May 1998, wild boars with classical swine fever (CSF) symptoms were detected in the southern part (Canton Ticino) of Switzerland. CSF virus was isolated from the submitted samples and RT-PCR followed by direct nucleotide sequencing of the 5' non-translated region showed that this virus was identical to the isolate previously recognized in wild boars from the area of Varese (Italy). In most animals, antibodies to CSF virus were detected as well. An immediate measurement was taken by limiting the movement of pigs and identifying both risk and surveillance zones. In order not to disturb potentially infected wild boars within their habitat a complete hunting prohibition for 2 months was enforced. The different possibilities of the control of CSF outbreaks in wild boars are discussed.  相似文献   

5.
To determine the persistence period of C-strain vaccine virus in immunized animals, domestic pigs and wild boars were vaccinated orally and killed on different days post vaccinationem (dpv). Tissue samples were taken at necropsy from both species for detection of C-strain virus. From domestic pigs nasal swabs and faeces were also collected. During the investigation period (2-12 dpv) vaccine virus could never be detected in nasal secretions and in faeces of vaccinated domestic pigs. In contrast, C-strain virus was found in organs until day 8 pv in domestic pigs and until day 9 pv in wild boars. Whereas in domestic pigs virus was detected in tonsils, Ln. mandibularis or in spleen, in wild boar it only was found in tonsils. We conclude that C-strain vaccine virus is not detectable in wild boars longer than 10-12 days after intake of the vaccine baits.  相似文献   

6.
  相似文献   

7.
A total of 193 faecal samples of adult Eurasian wild boars were collected at 12 enclosures across the Czech Republic and examined for Cryptosporidium infection using both microscopic and molecular tools. Cryptosporidium oocysts were not detected in any of the 193 faecal samples examined using the aniline-carbol-methyl violet staining method. Thirty-two positive cases of Cryptosporidium infection were detected using either genus- or species-specific nested PCR. Mono-infection with Cryptosporidium suis and Cryptosporidium pig genotype II were found in 13 and 7 cases, respectively. Five mixed infections of C. suis and Cryptosporidium pig genotype II were detected using PCR/RFLP with genus specific primers. The number of detected mixed infections increased 2.4 fold when a species-specific PCR was employed. No other Cryptosporidium spp. was detected. Unlike cryptosporidiosis of domestic pigs, C. suis was detected as a dominant species infecting adult Eurasian wild boars. There was no association between diarrhoea and the presence of Cryptosporidium infection in the Eurasian wild boars studied. This is the first report on the Cryptosporidium infection caused by C. suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa).  相似文献   

8.
In early 1992, a CSF epizootic was clinically recognised in a wild boar population of approximately 1300 animals within an area of 250km(2) located in the east of France. In order to check the CSF situation in wild boars outside this area, a serological survey was carried out in the rest of France, for 8 consecutive years (1991-1998). This paper reports on the results obtained during this survey which included wild boars shot during the hunting period but also boars reared within fences. Around 1000-2700 sera a year were tested for the presence of antibodies to classical swine fever virus (CSFV) and also to Aujeszky's disease virus (ADV). Out of 12025 sera tested over the whole period, 80 wild boars were found positive for CSF antibodies. Sixty of them were collected on wild boars shot during the years 1992-1994 in the epizootic area located in east of France and 10 were collected in Corsica during the years 1994-1996. The last four positive samples were single reactors coming from areas or farms, which were thereafter confirmed to be serologically negative. These results together with the fact that no disease has been reported so far illustrate that the French wild boar population is probably not concerned by CSF infection (excepted in the east of France where the disease has now become enzootic). Two hundred and forty nine sera were initially detected as CSF positive but confirmed secondarily as positive for border disease (BD) antibodies. This finding shows that wild boars are also susceptible to infection by ruminant pestiviruses. Four hundred and twenty three wild boars have been found positive for ADV antibodies. In addition, from 1993 to 1995, 909 samples were tested for the presence of antibodies to porcine reproductive and respiratory syndrome virus (PRRSV). Thirty three of them were positive. The results on AD and PRRS antibody detection show that wild boars may constitute a reservoir for various infectious diseases of pigs.  相似文献   

9.
To determine the persistence period of C‐strain vaccine virus in immunized animals, domestic pigs and wild boars were vaccinated orally and killed on different days post vaccinationem (dpv). Tissue samples were taken at necropsy from both species for detection of C‐strain virus. From domestic pigs nasal swabs and faeces were also collected. During the investigation period (2–12 dpv) vaccine virus could never be detected in nasal secretions and in faeces of vaccinated domestic pigs. In contrast, C‐strain virus was found in organs until day 8 pv in domestic pigs and until day 9 pv in wild boars. Whereas in domestic pigs virus was detected in tonsils, Ln. mandibularis or in spleen, in wild boar it only was found in tonsils. We conclude that C‐strain vaccine virus is not detectable in wild boars longer than 10–12 days after intake of the vaccine baits.  相似文献   

10.
A nested polymerase chain reaction (nPCR) protocol was applied to porcine semen to demonstrate the porcine circovirus type 2 (PCV2) shedding patterns and duration in naturally infected boars. Sperm morphology analysis was performed on a subset of samples to determine if the presence of PCV2 DNA in semen was associated with reduced semen quality. Semen was collected serially from 43 boars representing 6 breeds, aged 33.9 to 149.3 weeks. Of the 903 semen samples collected, 30 samples (3.3%) were positive for PCV2 DNA by nPCR from 13 boars. Boars shedding PCV2 DNA in semen ranged between 35.9 and 71.0 weeks of age, and shedding occurred during a period of up to 27.3 weeks. A semen nPCR test was 2.6 times more likely to be positive when collected from pigs that were < or =52 weeks of age, and 3.0 times more likely to be positive when collected from pigs that were < or =26 weeks from time of entry into the stud main unit (generalized estimating equations: P = 0.02; 95% confidence interval [CI] of the odds ratio 1.2 to 5.5, and P = 0.01; 95% CI of the odds ratio 1.3 to 6.9, respectively). These results demonstrate a sporadic and long-term shedding pattern of PCV2 DNA in semen from naturally infected boars. PCV2 DNA in semen does not appear to have detrimental effects on sperm morphology; however, boar age and, possibly, breed may contribute to the persistence of PCV2-shedding in semen.  相似文献   

11.
The objective of this research was to determine the effect of vaccination against porcine circovirus type 2 (PCV2) on ejaculate characteristics, PCV2-specific antibody titers in serum, viremia, and viral shedding in the semen of PCV2-positive boars. Before vaccination, all boars were confirmed by PCR to be naturally infected with PCV2. The boars were vaccinated with a commercial killed vaccine against PCV2 (n = 5) or served as controls and received 2 mL of 0.9% saline (n = 5). Semen and blood samples were collected before vaccination at wk 0 and at 7-d intervals thereafter until wk 8. Sperm concentration and characteristics of sperm motility were assessed using a computer-assisted sperm analysis system, and sperm morphology was evaluated using light microscopy after staining. The PCV2 antibody titers were determined in serum using an ELISA, and the genomic copy numbers of PCV2 DNA in serum and semen were determined by real-time PCR. In general, there were no effects of treatment or treatment × week on semen or sperm characteristics (P > 0.10). An effect of treatment × week was detected for serum antibody titers (P < 0.01). Compared with controls, PCV2 antibody titers in vaccinated boars were less (P < 0.01) at wk 7 (1.01 ± 0.05 titer/mL vs. 1.23 ± 0.05 titer/mL) and tended (P = 0.07) to be less at wk 8 (1.05 ± 0.05 titer/mL vs. 1.17 ± 0.05 titer/mL). There were no effects of treatment or treatment × week for serum and semen genomic copy numbers of PCV2 DNA (P > 0.10). There was a tendency (P = 0.09) for an effect of week on serum viral load. It was evident that during this experiment, boars experienced reoccurring PCV2 infection, and the detection of an increased PCV2 DNA load in serum preceded that in semen; the duration of reoccurring infection appeared to be less in vaccinated boars compared with controls. In summary, vaccination against PCV2 can reduce antibody titers when given postinfection and has no dramatic effect on indicators of semen quality. Vaccination against PCV2 in naturally infected boars can also decrease the length of reoccurring infection and decrease the duration of viral shedding in semen.  相似文献   

12.
OBJECTIVE: To determine susceptibility of European wild boars (Sus scrofa) to infection with pseudorabies virus (PrV) and to characterize the virulence of a wildboar PrV isolate for wild and domestic pigs. ANIMALS: 18 wild boars and 16 domestic pigs. PROCEDURE: Three groups of 4 wild boars were inoculated with PrV Bartha, Kaplan, and a wild-boar isolate (BFW1) and housed with uninfected pigs. Two groups of domestic pigs (4 and 8 pigs/group, respectively) were inoculated with various doses of BFW1. Animals were observed daily for clinical signs, and samples were tested for PrV excretion and homologous antibodies. After reactivation of latent infection by induced immunosuppression, PrV was detected in tissues of necropsied animals, using cell culture and a polymerase chain reaction (PCR). RESULTS: Clinical signs depended on virulence of the PrV strain and dose of inoculum. Only infection with PrV Kaplan resulted in severe disease and death. Virus was isolated from nasal and genital swab specimens. Antibodies were first detected on day 7 after inoculation; a specific humoral immune response was delayed in BFW1-infected animals. Virus was isolated from various tissues of Kaplan-infected wild boars, whereas mainly viral DNA was detected in a few tissues of Bartha- and BFW1-infected animals, using PCR after immunosuppression. CONCLUSIONS AND CLINICAL RELEVANCE: European wild boars are susceptible to transmission of PrV infection from domestic pigs and vice-versa. The PrV isolate BFW1 is of low virulence and seems to be adapted to the wild boar population from which it was isolated.  相似文献   

13.
This report describes the first case of postweaning multisystemic wasting syndrome (PMWS) in wild boar in Croatia. During the winter season of 2004, eight wild young piglets (of approximately 2 to 5 months of age) were found dead in a fenced hunting area. Polymerase chain reaction (PCR) was carried out on mesenteric lymph nodes and all animals yielded positive results. In one of these animals diagnosis of PMWS was established based on the three key diagnostic criteria including the clinical manifestation, moderate lymphoid lesions consisting of lymphocyte depletion and granulomatous inflammation, and detection of the presence of PCV2 genome within the lymphoid lesions by in situ hybridisation (ISH). Three additional wild piglets had also mild PMWS-like lesions and a low amount of PCV2 was also found. No PMWS-like lesions or PCV2 genome were detected in the rest of the wild piglets studied. Three PCR-positive isolates were partially sequenced, which confirmed the diagnosis of PCV2 and demonstrated that the three sequences were genetically identical. The phylogenetic analysis of a representative PCV2 isolate indicated that its sequence (DQ875444) is grouped in a separate branch with Hungarian isolate (AY256460) and differs from any of the annotated sequences.  相似文献   

14.
This work aimed to detect and study natural co-infection of Circoviridae torque teno virus (TTV) and porcine circovirus 2 (PCV2) in the swine reproductive apparatus. Semen and organs from 17 boars were tested by nested and real-time PCR. PCV2 was amplified from semen (47%), lymph nodes (84.6%) and testicles (35.3%). TTV2 was amplified from 16/17 testis and 13/13 lymph nodes. TTV1 DNA was detected in fewer testicle samples (2/17), which were also TTV2 positive. Analyzed ovaries, follicular fluid and uteri of 83 culled sows showed TTV2, TTV1 and PCV2 from 49.3%, 30.1% and 6.0% of the sows, respectively. Sperm analysis indicated insignificant differences between PCV2 and TTVs positive and negative boars. The most frequent pathologic lesion in sows was endometritis (28.9%), but this was unassociated with PCV2 or TTVs detection. These findings question the importance of PCV2 and TTV2 natural co-infection in the pathology of porcine reproductive failures.  相似文献   

15.
The aim of the present study was to survey the prevalences of the enteric pathogens Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis in Swedish growing pigs and in the Swedish wild boar population and to relate these findings to clinical signs. The study included 105 randomly selected herds, constituting approximately one third of Swedish herds with a herd size of >100 sows. The herds were located all over the country. In these herds, growth promoters were not used and pigs sampled were not subjected to any medication. From each herd, samples were taken from 10 growing pigs aged 8-12 weeks, corresponding to approximately 2.5% of all growing pigs present in the herd at the sampling occasion. If possible, the samples were taken from pigs with diarrhoea. Forty-eight faecal samples and 71 rectal swabs were also taken from free-living wild boars (31 piglets, 19 growers and 21 adult animals) at shooting. The samples were analysed by culture and biochemical tests for the presence of Brachyspira spp. and by nested PCR for the presence of L. intracellularis. Brachyspira hyodysenteriae was not demonstrated in any sample. Brachyspira intermedia was detected in 22 samples originating from 15 herds, Brachyspira innocens/Brachyspira murdochii was detected in 370 samples from 82 herds and B. pilosicoli was detected in 134 samples originating from 34 herds. In 21 herds and in 534 samples, no Brachyspira spp. were detected. Lawsonia intracellularis was demonstrated in 285 samples from 50 herds. Further, 418 samples from conventional herds were negative with respect to L. intracellularis and in 345 samples the PCR had been inhibited. All samples from the wild boars were negative for Brachyspira spp., 12 of 48 samples were negative for L. intracellularis, and in 36 wild boar samples, the PCR was inhibited.  相似文献   

16.
Faecal samples from 224 roe deer (Capreolus capreolus) and 381 wild boars (Sus scrofa) shot during the 2008-2009 hunting season (August-January) in Galicia (NW Spain) were examined to determine the presence and intensity of infection by Cryptosporidium and Giardia. Analysis of a single sample from each of the roe deer revealed that the prevalence of cryptosporidiosis and giardiosis was 1.3% and 5.3% respectively. The prevalence of Giardia infection was significantly higher in juvenile female roe deer than in adult females, but no other significant differences were found in relation to age and sex. In wild boars, the prevalence of cryptosporidiosis and giardiosis was 7.6% and 1.3% respectively. The prevalence of Cryptosporidium infection was significantly higher in juvenile male wild boars than in adult males, but no other significant differences were found in relation to age or sex. In both groups of wild animals, the number of Cryptosporidium oocysts per gram of faeces (OPG) ranged from 5 to 200 and the number of Giardia cysts per gram of faeces (CPG) was between 5 and 47; there were no significant differences between the two groups with respect to number of infections. This is the first large study of Cryptosporidium and Giardia in roe deer and wild boars in hunting areas in Spain and the results demonstrate a low, but widespread prevalence of Cryptosporidium and Giardia in these animals.  相似文献   

17.
Evidence of exposure (i.e. seroprevalence) to Aujeszky's disease virus (ADV) is high among wild boars from south-central Spain. This research aims to determine the presence of ADV by molecular detection, and to describe the patterns of ADV infection in wild boars. Tonsils (TN) and trigeminal ganglia (TG) for ADV molecular detection, and sera were collected from wild boars (n = 192) in 39 hunting estates from south-central Spain (2004/2005). A nested polymerase chain reaction (PCR) for a fragment of the ADV surface glycoprotein B was performed on collected tissues. Individual status of presence of viral DNA was tested against explanatory variables by means of a Generalized Linear Mixed Model (GLIMMIX) analysis. Viral detection prevalence was 30.6 ± 6.7%. Although there was an increasing pattern with age and females presented higher prevalences, no statistically significant influence of sex and age was found for viral presence. Molecular testing in TN and TG allowed classifying infection status into (i) ADV negative (in both TN and TG), (ii) only positive in TN, (iii) only positive in TG and (iv) positive in both TN and TG. ADV DNA was statistically more frequently evidenced in TN in females than in males. With the exception of one individual, all wild boars with presence of ADV DNA in TN and TG or only in TG reacted positive in the ELISA. In contrast, animals with only ADV DNA in TN serorreacted positively and negatively. Interestingly, 45% of the PCR positive wild boars (n = 59) were seronegative in the serological test, all of them with viral DNA only in TN. Our results provide evidence for latency of ADV in wild boars and stress the fact that antibody detection based tests may fail to detect a proportion of recently infected animals. This is of great concern since current management schemes in our study promote animal translocation for hunting purposes, with the associated risk of under-detecting ADV infected individuals when using serology to screen for ADV infection.  相似文献   

18.
Porcine circovirus type 2 (PCV2) is an economically important pathogen. It has been demonstrated that PCV2 DNA can be detected in boar semen by PCR; however, the biological relevance of this is unknown. The objectives of this study were to determine if semen positive for PCV2 DNA is infectious (1) in a swine bioassay, or (2) when used for artificial insemination. For the first objective, 4-week-old pigs were inoculated intraperitoneally with PCV2 DNA-negative (bioassay-control; n = 3), PCV2a DNA-positive (bioassay-PCV2a; n = 3), or PCV2b DNA-positive (bioassay-PCV2b; n = 3) raw semen, or PCV2 live virus (bioassay-positive; n = 3), respectively. Pigs inoculated with PCV2 DNA-positive semen and PCV2 live virus became viremic and developed anti-PCV2 antibodies indicating that the PCV2 DNA present in semen was infectious. For the second objective, three Landrace gilts were inseminated with PCV2 DNA-negative semen (gilts-controls) from experimentally-infected boars, and six gilts were artificially inseminated with semen positive for PCV2a DNA (gilts-PCV2a; n = 3) or PCV2b DNA (gilts-PCV2b; n = 3). Serum samples collected from the gilts in all groups remained negative for anti-PCV2 antibodies for the duration of the experiment. In addition, fetal serum samples from all 105-day-gestation fetuses were negative for anti-PCV2 antibodies or PCV2 DNA. Under the conditions of this study, PCV2 DNA-positive semen was not infectious when used to artificially inseminate gilts; however, it was demonstrated to be infectious in a swine bioassay model and therefore is a potential means of PCV2 transmission amongst swine herds.  相似文献   

19.
The objective of this work was to investigate the susceptibility of rabbits and mice experimentally inoculated with porcine circoviruses type 1 (PCV1) and type 2 (PCV2) to infection and development of disease and/or lesions. Forty six New Zealand rabbits and 50 ICR-CDI mice were both divided into two groups comprising PCVI and PCV2 inoculated animals, and a third group inoculated with non-infected cell culture medium. Rabbits were inoculated intranasally while mice were inoculated intraperitoneally. Clinical signs and body weights were recorded at the start of the experiment and at necropsy. Animals were bled, euthanised and necropsied at days 0, 3, 7, 10, 14 and 20 post-inoculation and samples were collected for histopathological, serological, in situ hybridisation and PCR analysis. No clinical signs or gross and microscopic lesions compatible with PCV2 infections such as those seen in pigs were observed. No presence of PCV2 nucleic acid was detected in rabbits and mice by in situ hybridisation. Only one mouse inoculated with PCV1 seroconverted on day 20 P1. PCV1 and PCV2 genome was detected in serum by PCR in mice inoculated with each porcine circovirus, while rabbits were negative for both viral types. These studies indicated that porcine circoviruses did not cause any disease or microscopic lesions in inoculated rabbits and mice during the experimental period. However, intraperitoneally inoculated mice might have harboured PCV2 in circulation without evidence of viral replication.  相似文献   

20.
Superficial inguinal lymph nodes from 72 wild boars examined in a previous immunohistochemical (IHC) study on porcine circovirus type 2 (PCV2) were selected for a PCV2 polymerase chain reaction (PCR) analysis. Four of these lymph nodes were PCV2-IHC strongly positive with PMWS histological lesions (outcome 1), 6 weak to mild PCV2-IHC positive without PMWS histological lesions (outcome 2) and 62 PCV2-IHC negative. Considering IHC the gold standard for diagnosis, the aims of the study were to evaluate the suitability of the PCV2-DNA extraction from formalin-fixed and paraffin-embedded (FFPE) tissue and the sensitivity and specificity of PCR under two IHC interpretations criteria: (A) the sample was considered positive if the result was outcome 1; (B) the sample was considered positive if the result was outcome 1 or 2. Under (A) criteria, sensitivity and specificity of PCR were 100% and 89.7%, respectively; the Cohen''s Kappa coefficient was 0.49. Under (B) criteria, sensitivity and specificity of PCR were 80.0% and 95.2%, respectively; the Cohen''s Kappa coefficient was 0.72. The high Cohen''s Kappa coefficient under the (B) interpretative criteria indicates good agreement between the two methods. In conclusion, 1) DNA extracted from FFPE specimens of wild boar is suitable for PCR and further represents a screening test for PCV2/PCVD (PCV2 Diseases) investigations in wild boar as well; 2) routine histological sampling can also be useful for PCV2 virological studies in wild boar.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号