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1.
A particular variant of the maedi visna virus (MVV) that although present in blood causes no clinical signs in infected sheep has been described. This variant carries a 13-14 nucleotide deletion in the R region of the proviral long terminal repeats. The hypothesis that this specific deletion may be associated with low pathogenicity has been investigated by comparing the distribution of proviral sequences, the histopathological lesions and the expression of viral proteins in the brain, lungs and udders of sheep naturally infected with viral strains carrying the deletion. Provirus could be demonstrated in most of the tissues examined from sheep infected with either type of virus, and the tissue-derived virus carried the typical deletion in the study flock animals. Histopathological analysis revealed that the lungs were significantly less affected in the animals infected with virus carrying the deletion. Concomitantly, viral expression was significantly reduced in the lungs of these animals. The findings suggest that the reduced pathogenicity of MVV with the specific deletion in the R region is not due to a restriction in the availability of specific tissues to infection, but is associated with a reduced capacity for viral expression in the lungs.  相似文献   

2.
The final results of experimental infections with virus recovered from the lungs of sheep suffering from progressive interstitial pneumonia (=zwoegerziekte=maedi) are reported. The virus could be reisolated from blood samples of all experimentally infected sheep. Every animal produced antibodies against the virus. The neutralising, complement-fixing and precipitating antibodies remained present in the blood for six years. Fourteen out of 21 intrapulmonarily infected sheep developed clinical and/or histopathological lung lesions and in three a meningo-leucoencephalitis was detected in addition. One of these three developed the clinical and pathological signs of 'visna' 14 months after inoculation. Signs of visna were seen in eight of 10 sheep that had been inoculated intracerebrally. Furthermore, nine of these sheep suffered from progressive interstitial pneumonia. Hence the name maedi-visna virus is proposed for the agent which causes both disease entities. Three sheep that yielded virus after infection and in which antibodies were detected, did not develop histopathological lesions.  相似文献   

3.
A lentivirus belonging to the group of retroviridae causes a chronic progressive interstitial pneumopathy (maedi) or a demyelinating encephalo-myelitis (visna) in sheep and goats. Pulmonary lesions of maedi as well as sero-positive, clinically healthy animals can be observed in Switzerland; visna, which even in countries with endemic infection does not occur frequently, is extremely rare. The head and cervical spine of an ewe with severe nervous troubles suspected of scrapie were submitted for postmortem examination. We found a demyelinating myelitis resembling visna. Immunocytochemical staining (PAP) to demonstrate the presence of the virus in paraffin sections was negative, but several animals of the flock proved to be seropositive for maedi/visna virus, which supports the histological diagnosis. Although there is no risk of an epidemic outbreak of maedi/visna in Switzerland, modes of transmission, eradication programmes and prophylactic measures successfully employed in countries with endemic maedi/visna are discussed.  相似文献   

4.
This study was performed to evaluate the infectivity of bradyzoites of two Besnoitia caprae isolates, BC-1 and BC-2, to inbred BALB/c mice. Each group of inbred BALB/c mice was inoculated intraperitoneally with 1 × 103, 1 × 104, 1 × 105, 5 × 105 and 1 × 106 of one of the two isolates of B. caprae bradyzoites. The mice were monitored daily for a period of 40 days for survival. After death of each mice, several passages from its peritoneal washing and tissues were analyzed using ribosomal DNA-specific PCR assay. Marked differences in pathogenicity between the isolates were seen. All the inbred BALB/c mice infected with BC-2 survived but all the mice that were administered with 1 × 05, 5 × 105 and 1 × 106 BC-1 bradyzoites were died within 4–9 days post-infection (DPI). Histopathological examination of the tissues of the dead mice revealed hyperemia and necrosis with presence of mononuclear and polymorphonuclear cell infiltration in myocardium, spleen and intestines together with interstitial pneumonia and peritonitis. All inbred BALB/c mice in the 1 × 103 and 1 × 104 groups of BC-1 inoculated mice survived and they were euthanized after 40 DPI. Chronic inflammation with infiltration of mononuclear cells was evident in myocardium, spleen, alveolar septa of the lungs of most of the examined tissues with hemorrhagic enteritis in the mice infected with 1x106 bradyzoites. The mice infected with different doses of BC-2 were euthanized after 40 DPI and no lesion was seen in histopathological sections of their organs. All peritoneal washings and examined tissues were PCR positive in BC-1 group. This experiment is the first report to show inbred BALB/c mice as a relevant model for B. caprae and demonstrates that this strain of inbred BALB/c mice is a suitable animal model for biological studies and examination of pathogenesis for this species of Besnoitia. The present findings also provide evidence for significant differences between the two isolates of B. caprae.  相似文献   

5.
Serum samples were collected from 372 sheep and same number of goats from the three geopolitical zones of Borno state, Nigeria. The samples were tested for the presences of Toxoplasma gondii antibodies by enzyme-linked immunosorbent assay. Of these, 6.7% (25/372) and 4.6% (17/372) of sheep and goats, respectively, were found to be seropositive to T. gondii antibodies, both far less than the estimated global average of 31%. Results were statistically analyzed by chi-square (χ2) test. The results showed that age, environmental conditions, and farm location are the main determinants of prevalence of antibodies against T. gondii in the study area. Older animals (>3 years) are significantly more infected than younger animals (between 6 months and 1 year).The prevalence of anti T. gondii antibodies is significantly higher (P < 0.05) in both sheep and goats sampled from the southern zone than the northern zone. Animals from the southern zones are about four times more likely to be exposed to T. gondii infection than those in the northern zone, (sheep; odds ratio (OR) = 4.25, 95% confidence interval (CI) = 1.177–15.36, P = 0.018), (goats; OR = 4.38, 95% CI = 0.925–20.73, P = 0.04). Farm location in urban area was identified as a risk factor for sheep (OR = 6.06, 95% CI = 2.53–14.54, P = 0.000), and goats (OR = 4.99, 95% CI = 1.59–15.62, P = 0.004). Current data on prevalence of ovine and caprine T. gondii in Borno state are provided by the study as well as identifying the main risk factors associated with T. gondii infection in the area.  相似文献   

6.
Toxoplasmosis, an infection caused by Toxoplasma (T.) gondii Apicomplexa protozoan, is widespread in humans and other animal species, having already been reported in many countries and different climates. In Pakistan, no data is available on this aspect among food animals. This study was undertaken to determine the seroprevalence of T. gondii infection in sheep and goats. A total of 200 serum samples from sheep and goats, were collected from urban area of Rahim Yar Khan (Punjab), Pakistan and tested for Toxoplasmosis with a commercial latex agglutination kit (Eiken Chemical Co., Ltd. Japan). The overall seroprevalence of Toxoplasmosis was 19%. Goats had a significantly higher (p < 0.01) prevalence (25.4%) as compared to the sheep (11.2%); and higher (p < 0.01) in the female (24%) than in the males (19%) for both species. In the present study the male (both in sheep and goat) are found less seropositive T. gondii (OR = 0.23; 99% C.I. = 0.01, 1.81) as compared to female sheep and goat. The prevalence was significantly higher (p < 0.01) in adult sheep than younger animals. Among both the sheep and goats the group from 1–1.5 years are highly seropositive (OR = 1.75; 99% C.I. = 0.47, 6.51) as compared to the group less than one year of age followed by the 2–2.5 years age group (OR = 1.63; 99% C.I. = 0.50, 5.74) whereas group with more than 3 years of age least seropositive.  相似文献   

7.
The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n = 30), cattle (n = 36), sheep (n = 44), dog (n = 35), and poultry (n = 21) and cdt genes prevalence of the isolates were investigated. To determine the genetic diversity of these strains, random amplified polymorphic DNA–polymerase chain reaction (PCR) using a random primer (M13) was performed. The numbers of genotypes determined in human, cattle, sheep, dog, and poultry isolates were 19, 18, 17, 18, and 6, respectively. To find out the prevalence of cdt genes in C. jejuni isolates simultaneously, a multiplex PCR was performed. The prevalence of the separate cdt genes was found to vary from 69% to 100% for cdtA, 92% to 100% for cdtB, and 39% to 98% for cdtC. These rates without host discriminating were 95%, 98%, and 93% for cdtA, cdtB, and cdtC, respectively. The prevalence of all three cdt genes in strains originating from human, cattle, sheep, dog, and poultry were 87%, 67%, 84%, 89%, and 39%, respectively. These results showed the relatively high genetic heterogeneity and variation of cdt genes among C. jejuni isolates from various sources except for poultry isolates. This study gives baseline data on molecular characterization of C. jejuni strains from different sources.  相似文献   

8.
A study was conducted to determine the prevalence, larval burden, and associated gross pathological lesions of Oestrus ovis in sheep and goats slaughtered at Luna export abattoir in Central Oromia from November 2007 to March 2008. For this purpose, a total of heads of 431 goats and 369 sheep were thoroughly examined for the presence of first (L1), second (L2), and third (L3) larval stages according to standard procedures. O. ovis larvae were detected in 349(94.6%) sheep and 381(88.4%) goats. All three larval instars were observed in each study months. Statistically significant variation (χ 2 = 29.2676, df = 6, P < 0.05) was observed in the prevalence of O. ovis among small ruminants of different origins. Likewise, statistically significant (χ 2 = 68.3, df = 4, P < 0.05) difference was recorded in the prevalence of O. ovis in sheep and goats among different study months. The overall monthly prevalence ranged from 77.7% in November to 98.8% in March. The prevalence of O. ovis in small ruminants of less than 1 year of age was significantly (χ 2 = 8, df = 1, P < 0.05) higher than those with greater than 1 year of age. An overall proportion of 33.8%, 40.1%, and 26.1% were recorded for L1, L2 and L3, respectively. Whereas 6.8 monthly mean larval burden per individual infested animal was noticed. Out of the total infested heads in goats, 33.6% had catarrhal discharges, 16.8% purulent exudates, 64.83% rhinitis, 68.77% sinusitis, 14.2% pharyngitis, and 9.2% bloody exudates. Similarly, of the total infested heads of sheep, 18.9% purulent exudates, 80.8% rhinitis, 71.9% sinusitis, 13.5% pharyngitis, and 7.7% bloody exudates gross lesions were recorded.  相似文献   

9.
Sera from 497 sheep and 555 goats collected in a cross sectional study from different geographical locations in north-eastern Tanzania were examined for antibodies to Ehrlichia ruminantium using MAP 1-B ELISA technique. E. ruminantium antibodies were found in 68.6% (341/497) of sheep and 64.7% (359/555) of goats. Overall seroprevalence was 66.5% (700/1052). Infection rates were higher in sheep than goats (P < 0.05), in pastoral than in agro-pastoral production systems (P < 0.05) and in female sheep than males (P < 0.05). (131/143) 91.6% of the farms/flocks tested revealed sero-positive animals. E.ruminantium infections were found in all the geographical villages and districts tested. The infection rates per administrative district varied from 36.4% (Muheza) to 90% (Mkinga) in goats and from 11.9% (Muheza) to 94.6% (Mkinga) in sheep. The results shows E. ruminantium infection was prevalent and widely but unevenly distributed throughout the eight districts under study. These findings should be taken into consideration when future disease control and livestock upgrading programs are implemented.  相似文献   

10.
An allele-specific PCR was standardized to diagnose the mutation (Phe to Try) at residue 200 of the isotype 1 beta tubulin gene responsible for benzimidazole resistance in Haemonchus contortus adult and infective larvae. Adult and infective larvae of Haemonchus contortus were collected from sheep under different managemental practices (intensive and extensive) in temperate Himalayan regions (Mukteshwar and Kedarkhatta), sub-himalayan region (Pantnagar) of Uttarakhand state and subtropical region of Uttar Pradesh (Bareilly) in north-west India. Genotyping of adult H. contortus, collected from abomasi of slaughtered sheep reared under extensive management, by AS-PCR revealed that the frequency of resistant (r) alleles was significantly higher (P < 0.001) at Pantnagar (0.57) as compared to Bareilly (0.25) and Mukteshwar (0.08). Also, genotyping of infective larvae of the parasite from intensively managed sheep farms indicated that the frequency of resistant (r) alleles was significantly higher (P < 0.001) at Pantnagar (0.85) as compared to Kedarkattha (0.70) and Bareilly (0.62). The results revealed that managemental practices followed in the areas under study have a direct bearing on the spread of benzimidazole resistant alleles.  相似文献   

11.
A survey was conducted to identify tick species and determine the prevalence of tick infestation in small ruminants of Miesso District, West Harergie Zone. Collection and identification of the ticks were undertaken from November 2007 to April 2008. All visible individual adult ticks were collected from the body of 328 goats and 40 sheep. The prevalence of tick infestation in goats and sheep was found to be 89.9% and 87.5%, respectively. In this study, ten species of ticks which grouped under four genera were identified. The most abundant species found in this study were Boophilus decoloratus (60%), Rhipicephalus pulchellus (25.1%), and Amblyomma gemma (11%). Hyalomma dromedarii was the minor species observed on goats. The difference in the prevalence of tick infestation between sheep and goats was not statistically significant (Χ 2 = 0.22, p = 0.63) but found to be statistically significant between male and females (Χ 2  = 9.8, p = 0.003). Attention should be given to the control and prevention of ticks, since they cause sever damage to the skins of small ruminants and thereby reduce the foreign exchange of the country; they also transmit some diseases which can cause sever loss to the productivity of these animals.  相似文献   

12.
A study was carried out to estimate the prevalence, larval burden and risk factors of ovine and caprine oestrosis from December 2007 to May 2008 on 554 heads of randomly selected sheep and goat slaughtered at Ambo town, Western Shoa, Ethiopia. The results show an overall prevalence of 59.9% with infection rate of 69.8% and 47.3% in sheep and goats respectively. No statistically significant difference in the prevalence was noted with regard to the assumed risk factors like sex, nose color, face color, horned versus polled, origin, and months (p > 0.05). Sheep were nearly twice more likely to be infected as compared to goats (p = 0.0001, odds ratio (OR) = 1.975). Age of the animals was found to be protective (OR = 0.579; 95% confidence interval = 0.393, 0.853; p = 0.006). As compared to very fat animals, poor (p = 0.040, OR = 4.834), medium (p = 0.049, OR = 4.198), and fat (p = 0.022, OR = 5.795) body condition animals are more likely to be infected by Oestrus ovis larvae. Nasal and sinus cavity pathology is positively correlated with the total larval count (r = 0.56, p < 0.0001). Out of a total of 3,770 larvae collected, 57.5% were L1, 30.8% L2, and 11.7% L3 larvae. All the three larval instars were seen throughout the study months. It is concluded that oestrosis is a common problem in the study area and more prevalent in sheep than goats, in adult than young, and in animals with poor body condition.  相似文献   

13.
A visna-maedi-like disease was found in a Corriedale sheep from which a retrovirus sharing the group antigen of visna-progressive pneumonia virus was isolated from lung, brain, and spleen. Clinically, the sheep had acute neurologic signs and dyspnea. Pathologic examination showed lesions similar to both visna and maedi. In the lung, there was a patchy interstitial pneumonia with marked lymphoid hyperplasia. Changes in the central nervous system were necrotizing nonsuppurative encephalitis of the brain stem, poliomyelitis of the cervical cord, and ependymitis and subependymal gliosis of the ventricles. Histologically, the central nervous system lesions seemed to have arisen sequentially, perhaps in response to bursts of virus replication as the agent underwent possible antigenic mutation. The severe lesions in both the central nervous system and lungs suggested a virus strain with dual tropism.  相似文献   

14.
Eight sheep were inoculated with Icelandic maedi strain M 88; 2 sheep served as control sheep and were in close contact with the inoculated ones. Four of the sheep were inoculated via the respiratory tract with 7×106 TGID50 of strain M88 and the other 4 intracerebrally with 5×105 TGID50 of the same strain.Maedi M88 strain was isolated from peripheral blood leukocytes of all inoculated sheep. There was a striking difference between the 2 groups in the appearance of demonstrable viremia after inoculation. Viremia could be demonstrated in the intrapulmonarily inoculated sheep within 2–6 months but not until 8–11 months after inoculation in the intracerebrally inoculated ones. This finding is thought most probably to reflect a weak neurotropism of the strain used. After the first demonstration of viremia, maedi virus has been recovered quite reqularly in peripheral leukocytes of all intrapulmonarily inoculated sheep, but less regularly in the intracerebrally inoculated ones. Maedi virus was isolated from 1 of the uninoculated control sheep 15 months after inoculation.The first clinical case with a clinical appearance suggesting combined involvement of maedi and visna was found among the intrapulmonarily inoculated sheep, 8% months after inoculation. Histopathological examination and virus isolation confirmed maedi. The cause of paraplegia could not be confirmed. No histopathological changes were found and no virus isolation was made from the central nervous system of this animal.One of the intracerebrally inoculated sheep died suddenly without any observed clinical signs 11 months after inoculation. Histopathological examination revealed pulmonary lesions of maedi, but no visna lesions in the central nervous system, although maedi virus was isolated from various parts of brain.None of the other experimental sheep displayed clinical signs of maedi or visna during the observation period of 18 months.  相似文献   

15.
An epidemiological study with the objective to assess the prevalence of paramphistomosis in association with season, age, sex and breed was carried out in naturally infected sheep over a period of two years from February 2005 to January 2007. Gastrointestinal tract (GIT) and faecal examination were conducted monthly to monitor the seasonal occurrence of paramphistomosis. 793 sheep were examined in the first year, out of which 7.06% were positive for Paramphistomum infection. In the second year, 740 animals were investigated and 7.7% were infected. The overall prevalence of paramphistomosis was 7.3% with a mean of 56.50 ± 0.50 and 95% confidence interval (CI) (lower bound: 50.1469; upper bound: 62.8531). The prevalence of paramphistomosis through GIT examination (P = 0.593) was 7.6% at 95% CI (lower bound: −19.1186; upper bound: 57.1186) and the prevalence through faecal examination (P = 0.884) was 7.2% at 95% CI (lower bound: 5.7345; upper bound: 69.2655). Generally, season and age were the factors found to have a significant influence on the risk of paramphistomosis in sheep. The highest infection was found in the summer season (P < 0.005); lower age groups (P < 0.005) in males and in migratory (Bhakarwal) breed (P ≥ 0.005). Winter, adult animals, females and local breed reported low infection. The present study will be of great significance to understand the epidemiology of gastrointestinal helminthes of sheep initially in the resource poor communities of Himalayan region and will definitely be helpful to devise appropriate control strategies for paramphistomosis.  相似文献   

16.
Postmortem bronchoalveolar lavage of feline immunodeficiency virus-infected cats indicated an alveolitis process, and histological examination of their lungs confirmed the occurrence of alveolitis, parenchymatous lymphoplasmocytic infiltration and myomatosis. Similar lymphoid interstitial pneumonitis has been described in human and animal lentiviral diseases: lymphocytic interstitial pneumonitis in -1-infected human beings, and maedi in sheep infected by the maedi-visna virus. Such lymphoid interstitial pneumonitis may thus be a common feature of lentiviral infections.  相似文献   

17.
In order to evaluate embryo production in Morada Nova (white variety) ewes superovulated with porcine follicle-stimulating hormone, 20 cycling ewes were used as embryo donors and allocated into two groups according to age: group 1 (ewes aged 1–2 years; n = 9) or group 2 (ewes aged 3–4 years; n = 11). Embryo recovery was performed by laparotomy 5–6 days after oestrus. The evaluation of embryos was made under stereomicroscope according to International Embryo Transfer Society rules. The overall recovery rate was 64.6% (5.0 ±  0.7 structures per ewe) and 86.3% of the recovered structures were fertilized. Group 1 was superior (p < 0.05) to group 2 according to recovered (6.6 ±  0.9 vs 3.6 ±  0.8) and fertilized structures (5.6 ±  1.1 vs. 3.5 ±  0.7) per ewe. In conclusion, the ovarian response and the embryo production in Morada Nova (white variety) sheep subjected to a standard superovulation treatment were considered satisfactory. In addition, the use of multiple ovulation and embryo transfer in younger ewes (≤ 2 years old) of this sheep breed appears to be an efficient tool to accelerate the preservation of the Morada Nova (white variety) breed, since younger ewes are as responsive as older ones.  相似文献   

18.
A cross-sectional study was conducted from November 2008 to February 2009 to investigate the prevalence and intensity of infection and risk factors of gastrointestinal (GI) nematodes in small ruminants kept under the traditional husbandry system in two districts in southern Ethiopia. Faecal samples collected from a total of 510 small ruminants (284 sheep and 226 goats) and analysed by a modified McMaster technique revealed that 222 animals (43.5%) were found to be infected with one or more GI nematodes. Five identical genera of nematodes were found in both sheep and goats, which in order of predominance were Haemonchus (56.3%), Trichostrongylus (39.6%), Oesophagostomum (22.9%), Trichuris (21.6%) and Bunostomum (10.4%). No significant (p > 0.05) differences were observed between sheep and goats proportions except for Trichuris (p < 0.05). In both sheep and goats, most of the animals were heavily infected showing faecal egg counts (FECs) above 1,200 epg. Sheep had a significantly (p < 0.05) higher mean FEC than goats. In sheep and goats, both the prevalence of GI nematodes and mean FEC were significantly (p < 0.001) associated with body condition score and faecal consistency but not with district, sex and age (p > 0.05 for each factor). In conclusion, the observation of a strong association of GI nematodes with poor body condition coupled with heavy intensity of infection in the majority of infected animals and an abundance of nematode genera of widespread economic and pathological significance warrants the institution of appropriate control measures that should necessarily include improvement of the nutritional status of the animals.  相似文献   

19.
Digestibility and feeding trials for 10 and 90 days were conducted using 25 yearling Farta rams with a mean body weight (BW) of 16.8 ± 0.17 kg (mean ± SD) to study the effects of supplementation with sole or mixtures of noug seed meal (NSM) and wheat bran (WB) on feed intake, digestibility and BW change in Farta sheep fed hay. The experimental design was a randomized complete block design. The sheep were arranged in five blocks based on initial BW, and the five treatments were assigned randomly to each animal in a block. The five treatments comprised of ad libitum hay (control, T1) and ad libitum hay plus daily supplementation of 300 g dry matter (DM) sole WB (T2), 2WB:1NSM (T3), 1WB:2NSM (T4) and sole NSM (T5). Supplementation increased total DM (P < 0.01) and crude protein (CP) (P < 0.001) intake and promoted daily BW gain (P < 0.001). Non- supplemented sheep consumed more (P < 0.01) hay DM compared to the supplemented treatments, except T2. Among supplemented sheep, T5 had higher (P < 0.001) CP intake than the other treatments. Supplementation improved (P < 0.001) the digestibility of CP. Lack of statistical differences in daily BW gain between the different supplements used in this study suggests that sheep producers can use the different feed supplements considered in this study depending on their availability in the order of T4, T5, T3 and T2, respectively.  相似文献   

20.
A 3-year (2005–2007) retrospective study was carried out to investigate the occurrence of cystic echinococcosis (CE) in cattle and shoats (sheep and goats) slaughtered at Arusha municipal abattoir, Tanzania. A total of 115186 cattle and 99401 shoats were slaughtered. Cattle liver, lungs, spleen and heart condemnation rate was 16.35%, 13.04%, 2.09% and 3.06% respectively while 17.63%, 7.63%, 0.38% and 0.04% of shoats’ liver, lungs, spleen and heart respectively were condemned. A highly significant (p < 0.001) cystic echinococcosis (CE) infection rate was recorded in shoats (6.02%) than in cattle (4.2%) probably because of differences in grazing patterns. Cattle lungs were more affected by CE (22.5%) than liver (19.7%) while shoats liver were found to be more affacted (21%) than the lungs (19.3). A significant (p < 0.001) higher CE infection rate was observed in cattle spleen (15.5%) than shoats (9.7%). There was no significant (p > 0.05) difference between condemnation rates due to hydatidosis during rain and dry seasons probably because of chronicity of the disease. The study have established that CE is prevalent in animals slaughtered at Arusha abattoir and causes higher condemnation rates of edible offals. This merit for more extensive epidemiological investigations to better determine the prevalence, economic impact and public health importance of the disease in the region.  相似文献   

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