Development of a genetically modified nontoxigenic Pasteurella multocida toxin as a candidate for use in vaccines against progressive atrophic rhinitis in pigs   总被引：1，自引：0，他引：1  

To H  Someno S  Nagai S 《American journal of veterinary research》2005,66(1):113-118

OBJECTIVE: To construct a genetically modified nontoxigenic Pasteurella multocida toxin (PMT) and examine its immunoprotective activity against challenge exposure with wild-type PMT in pigs. ANIMALS: 5 healthy pigs. PROCEDURE: A nontoxigenic PMT was created by replacing the serine at position 1164 with alanine (S1164A) and the cysteine at position 1165 with serine (C1165S). Toxic activity was determined by use of the guinea pig skin test and mouse lethality test. Three pigs were vaccinated twice with the modified PMT, and the remaining 2 pigs served as nonvaccinated control animals. Vaccinated and control pigs were challenge exposed with wild-type PMT. Pigs were euthanatized and necropsied on day 14 after challenge exposure. Turbinate atrophy was examined macroscopically and assigned a score. Serum anti-PMT antibodies were determined by use of an ELISA. RESULTS: The genetically modified PMT was characterized by a total lack of toxic activity. Pigs vaccinated with the modified PMT became seropositive; in contrast, control pigs remained seronegative. Necropsy revealed that the 2 control pigs had moderate and severe turbinate atrophy, respectively, whereas the 3 vaccinated pigs did not have any lesions in the turbinates or abnormalities in other organs. CONCLUSIONS AND CLINICAL RELEVANCE: Modification by use of S1164A and C1165S leads to a complete loss of toxic effects of PMT without impairment of the ability to induce protective immunity in pigs. Analysis of these results suggests that genetically modified PMT may represent a good candidate for use in developing a vaccine against progressive atrophic rhinitis in pigs.  相似文献   

Development and validation of species-specific primers that provide a molecular diagnostic for virus-vector longidorid nematodes and related species in German viticulture     

Judith Hübschen  Lilo Kling  Ulrike Ipach  Volker Zinkernagel  Derek Brown  Roy Neilson 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(9):883-891

The nematode species Longidorus attenuatus, L. elongatus, L. macrosoma and Paralongidorus maximusare economically important pests to the viticulture industry due to their ability to vector two nepoviruses (Raspberry Ringspot Virus and Tomato Black Ring Virus) to grapevines. In Germany, these species occur in vineyard soil with other non-vector but morphologically similar longidorid species, L. helveticus, L.profundorum and L. sturhani. Species-specific primers were designed from ribosomal DNA for all seven species to facilitate taxonomic identification for non-specialists. Primers were assessed for their reliability by screening, where possible, a number of populations of each species. Furthermore, their selectivity and sensitivity were determined when challenged with closely related longidorid species and general nematode communities typical of vineyard soil. A multiplex approach using a common forward primer combined with species-specific reverse primers enabled three target nematode species to be detected in the same PCR reaction. All primers were highly specific, detecting all nematode developmental forms from disparate populations and were sufficiently sensitive to detect a single target nematode within a whole nematode community typical of a vineyard soil comprising of a range of non-target species. Given their specificity, sensitivity and reliability, these diagnostic primers should be of great benefit to both phytosanitary/quarantine services related to the viticulture industry and also as a decision management tool for growers.  相似文献   

Real-time detection of <Emphasis Type="Italic">Phytophthora nicotianae</Emphasis> and <Emphasis Type="Italic">P. citrophthora</Emphasis>in citrus roots and soil     

Antonio Ippolito  Leonardo Schena  Franco Nigro  Vincenza Soleti ligorio  Thaer Yaseen 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(8):833-843

Two primers, specific for Phytophthora nicotianae (Pn6) and P. citrophthora (Pc2B), were modified to obtain Scorpion primers for real-time identification and detection of both pathogens in citrus nursery soils and roots. Multiplex PCR with dual-labelled fluorogenic probes allowed concurrent identification of both species ofPhytophthora among 150 fungal isolates, including 14 species of Phytophthora. Using P. nicotianaespecific primers a delayed and lower fluorescence increase was also obtained from P. cactorumDNA. However, in separate real-time amplifications, the aspecific increase of fluorescence from P. cactorum was avoided by increasing the annealing temperature. In multiplex PCR, with a series of 10-fold DNA dilutions, the detection limit was 10 pg l^-1 for P. nicotianaeand 100 pg l^–1 for P. citrophthora, whereas in separate reaction DNA up to 1 pg l^-1 was detected for both pathogens.Simple and rapid procedures for direct DNA extraction from soil and roots were utilised to yield DNA whose purity and quality was suitable for PCR assays. By combining these protocols with a double amplification (nested Scorpion-PCR) using primers Ph2-ITS4 amplifying DNA from the main Phytophthora species (first round) and PnB5-Pn6 Scorpion and Pc2B Scorpion-Pc7 (second round), it was possible to achieve real-time detection of P. nicotianaeand P. citrophthora from roots and soil. The degree of sensitivity was similar to that of traditional detection methods based on the use of selective media. The analyses of artificially and naturally infested soil showed a high and significant correlation between the concentration of pathogen propagules and the real-time PCR cycle threshold.  相似文献   

Molecular study on chicken tumor necrosis factor receptor-II and tumor necrosis factor receptor-associated factor-5     

Abdalla SA  Horiuchi H  Furusawa S  Matsuda H 《Veterinary immunology and immunopathology》2004,98(1-2):31-41

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) were identified as signal transducers for the tumor necrosis factor receptor (TNFR) superfamily. In this study, we cloned and characterized two genes that encode chicken TNFR-II and TRAF5. The initial cDNA fragments were obtained by suppressive subtractive hybridization (SSH) of chicken spleen cells with or without lipopolysaccharide stimulation (Salmonella typhimurium SL1181 (RE-mutant)). The results showed that chicken TNFR-II is 1518 bp in length with an open reading frame (ORF) of 1386 bp having 31% homology with human TNFR-II. Expression analysis of chicken TNFR-II revealed that it is highly expressed in the spleen and bursa of Fabricius. The chicken cell lines IN24, MSB1 and 1104B express TNFR-II abundantly. The time course analysis of expression in spleen, bursa of Fabricius and IN24 cell line showed that TNFR-II is maximally expressed at 6 h after stimulation in bursa of Fabricius and after 8 h stimulation in the IN24 cell line. With regard to TRAF5, the complete sequence was 1936 bp in length with an ORF of 1671 bp that showed 71.3% homology with human TRAF5. Expression analysis showed that, among the tissues examined, TRAF5 was strongly expressed in spleen and bursa of Fabricius, while among the cell lines examined, it was maximally expressed in IN24. Thus, both genes were expressed in the same tissues and cell line among examined materials. These results suggest that chicken TNFR-II may interact with TRAF5 adaptor protein to complete its signal transduction pathway.  相似文献   

Chicken peripheral blood CD3+CD4-CD8- cells are regulated by endocrine and nerve systems     

Kushima K  Yoshida K  Fujita M  Shigeta A  Horiuchi H  Matsuda H  Furusawa S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(2):143-148

The existence of CD3(+)CD4(-)CD8(-) T cells in thymus and spleen has already been known. However, because of the presence of large amounts of thrombocytes in peripheral blood (PB), the proportion of CD3(+)CD4(-)CD8(-) T cells in PB has yet to be investigated. Therefore, the proportion of peripheral T cell-subsets was investigated in 6-week-old chickens. The percentage of CD3(+) cells, CD4(+) cells, CD8 alpha(+) cells, CD8 beta(+), and CD3(+)CD4(-)CD8(-) cells was 76%, 41%, 14%, 5%, and 15%, respectively. The proportion of CD3(+)CD4(-)CD8(-) cells in PB increased during egg-laying periods and in chickens treated with an analog of estrogen, while it decreased with age and in response to restraint stress. All of the CD3(+)CD4(-)CD8(-) cells expressed TCR1, and did not have NK activity. CD3(+)CD4(-)CD8(-) cells represent about 60% of peripheral TCR1(+) cells. These findings indicate that the proportion of CD3(+)CD4(-)CD8(-) cells is regulated by the endocrine and nerve systems.  相似文献   

Usefulness of MRI compared with CT for diagnosis of mesenteric lymphoma in a dog     

Yasuda D  Fujita M  Yasuda S  Taniguchi A  Miura H  Hasegawa D  Orima H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1447-1451

We evaluated the usefulness of MRI and compared it with CT for diagnosis of mesenteric lymphoma in a dog. The results in the plain CT, dynamic CT and plain MR (T1WI and T2WI) images suggested that the mass was a large single nodular lesion with abundant blood perfusion. On enhanced MRI(T1WI) , the mass was depicted as a tumor with adhesion to the gut wall. Exploratory laparotomy confirmed the mass was consistent with the findings on enhanced MRI. We think that MRI might be a useful imaging tool for diagnosis of canine mesenteric lymphoma.  相似文献   

Simultaneous observation of the GnRH pulse generator activity and plasma concentrations of metabolites and insulin during fasting and subsequent refeeding periods in Shiba goats     

Matsuyama S  Ohkura S  Ichimaru T  Sakurai K  Tsukamura H  Maeda K  Okamura H 《The Journal of reproduction and development》2004,50(6):697-704

The time course of GnRH pulse generator activity and plasma concentrations of energy substrates and insulin were simultaneously observed in female goats during 4-day fasting and subsequent refeeding in the presence or absence of estrogen for a better understanding of the mechanism of energetic control of gonadotropin secretion in ruminants. The GnRH pulse generator activity was electrophysiologically assessed with the intervals of characteristic increases in multiple-unit activity (MUA volleys) in the mediobasal hypothalamus. In estradiol-treated ovariectomized (OVX+E2) goats, the MUA volley intervals increased as fasting progressed. Plasma concentrations of non-esterified fatty acid and ketone body increased, while those of acetic acid and insulin decreased during fasting. The MUA volley intervals and plasma concentrations of those metabolites and insulin were restored to pre-fasting levels after subsequent refeeding. In ovariectomized (OVX) goats, changes in plasma metabolites and insulin concentrations were similar to those in OVX+E2 goats, but the MUA volley intervals were not altered. The present results demonstrated that fasting suppressed GnRH pulse generator activity in an estrogen-dependent manner. Changes in plasma concentrations of energy substrates and insulin during fasting were associated with the GnRH pulse generator activity in the presence of estrogen, but not in the absence of the steroid in female goats.  相似文献   

Review of <Emphasis Type="Italic">Coenosia attenuata</Emphasis> Stein and its first record as a predator of important greenhouse pests in Turkey     

Daniel Pohl  Stefan Kühne  İsmail Karaca  Eckard Moll 《Phytoparasitica》2012,40(1):63-68

Greenhouses in Turkey under integrated pest management can be colonized by a high number predatory flies of the species Coenosia attenuata Stein, 1903 (Muscidae: Coenosia Meigen, 1826). Studies have shown that Coenosia predators do not simply colonize greenhouses from the outside for short periods but instead they are able to complete their developmental cycle in the greenhouse soil and can become established there for a long period of time. C. attenuata is indigenous to the Palaeotropical region. Its prey spectrum includes whiteflies, black fungus gnats and leaf-mining flies. Studies of the natural occurrence of these predaceous flies in greenhouses led to a recognition of the significance of this complex of beneficials for the control of important greenhouse pests. They can build up effective populations under greenhouse conditions, and as non-specific predators can feed on a variety of pest groups and on innocuous species.  相似文献   

Feeding potential of <Emphasis Type="Italic">Cryptolaemus montrouzieri</Emphasis> against the mealybug <Emphasis Type="Italic">Phenacoccus solenopsis</Emphasis>     

Harmeet Kaur  J. S. Virk 《Phytoparasitica》2012,40(2):131-136

Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an exotic species native to the USA, damaging cotton and other plant families. The feeding potential of different development stages of Cryptolaemus montrouzieri Mulsant, a biological control agent against mealybugs, was investigated on different development stages of P. solenopsis. Fourth instar grubs and adults of C. montrouzieri were the most voracious feeders on different instars of mealybug. The number of 1^st instar nymphs of mealybug consumed by 1^st, 2^nd, 3^rd and 4^th instar larvae and adult beetles of C. montrouzieri was 15.56, 41.01, 125.38, 162.69 and 1613.81, respectively. The respective numbers of 2^nd and 3^rd instar nymphs of mealybug consumed were 11.15 and 1.80, 26.35 and 6.36, 73.66 and 13.32, 76.04 and 21.16, 787.95 and 114.66. The corresponding figures for adult female mealybugs were 0.94, 3.23, 8.47, 12.71 and 73.40, respectively. The results indicate that C. montrouzieri has the potential to be exploited as a biocontrol agent in North India; inoculative releases of 4^th instar larvae and adults may provide instant control of P. solenopsis. Field experiments should be conducted to determine the efficiency of the ladybird on this mealybug.  相似文献   

Advanced lentil lines screened for resistance to <Emphasis Type="BoldItalic">Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="BoldItalic">lentis</Emphasis> under greenhouse and field conditions     

N. Mohammadi  H. Puralibaba  E. Mohammadi Goltapeh  A. Babaie Ahari  B. Pakdaman Sardrood 《Phytoparasitica》2012,40(1):69-76

Fusarium oxysporum f. sp. lentis is the most important pathogen of lentil plants, and most areas under lentil cultivation are reported to have a fusarium wilt disease background. The plants are infected in the seedling stage and later stages of their development. Fusarium wilt disease, which has appeared at high incidence rates during recent years, has caused sharp drops in the yield, especially in Moghan, in the northwest of Iran. Forty-five isolates of the pathogen were collected from different regions of the country with two isolates from ICARDA in the summer of 2008 and identified using Nelson’s key. The pathogenicity of the collected isolates was studied on a sensitive line (ILL 4605) under greenhouse conditions and significant differences in pathogenicity were found among them. The most pathogenic isolates from three provinces, East Azerbaijan (EA 30), Ardebil (Ar 3) and Khorasan (Kh 45), were selected and used in screening of 55 developed lines under greenhouse and field conditions. In the greenhouse, test plants were inoculated by immersing root tips in spore suspension and sowing seeds in pre-infested pot soil. Field tests were carried out in a naturally highly infested farm. At all stages, the plant response to the disease was based on the percentage of dead plants. Cluster analyses of the greenhouse and field data led to the selection of three lines (81S15, FLIP2007-42 L and FLIP2009-18 L) that were resistant under greenhouse and field conditions.  相似文献