Serological evidence of continuing high Usutu virus (Flaviviridae) activity and establishment of herd immunity in wild birds in Austria   总被引：2，自引：0，他引：2  

Meister T  Lussy H  Bakonyi T  Sikutová S  Rudolf I  Vogl W  Winkler H  Frey H  Hubálek Z  Nowotny N  Weissenböck H 《Veterinary microbiology》2008,127(3-4):237-248

Usutu virus (USUV), family Flaviviridae, has been responsible for avian mortality in Austria from 2001 to 2006. The proportion of USUV-positive individuals among the investigated dead birds decreased dramatically after 2004. To test the hypothesis that establishment of herd immunity might be responsible, serological examinations of susceptible wild birds were performed. Blood samples of 442 wild birds of 55 species were collected in 4 consecutive years (2003--2006). In addition, 86 individuals from a birds of prey rehabilitation centre were bled before, at the peak, and after the 2005 USUV transmission season in order to identify titre dynamics and seroconversions. The haemagglutination inhibition test was used for screening and the plaque reduction neutralization test for confirmation. While in the years 2003 and 2004 the proportion of seropositive wild birds was <10%, the percentage of seroreactors raised to >50% in 2005 and 2006. At the birds of prey centre, almost three quarters of the owls and raptors exhibited antibodies before the 2005 transmission season; this percentage dropped to less than half at the peak of USUV transmission and raised again to almost two thirds after the transmission season. These data show a from year to year continuously increasing proportion of seropositive wild birds. The owl and raptor data indicate significant viral exposure in the previous season(s), but also a number of new infections during the current season, despite the presence of antibodies in some of these birds. Herd immunity is a possible explanation for the significant decrease in USUV-associated bird mortalities in Austria during the recent years.  相似文献   

Grapevine rupestris stem pitting virus: a new pathogen of grapevine in Serbia     

Stanković  Ivana  Zečević  Katarina  Delibašić  Goran  Jović  Jelena  Toševski  Ivo  Krstić  Branka 《植物病害和植物保护杂志》2023,130(1):181-188

Journal of Plant Diseases and Protection - Grapevine rupestris stem pitting-associated virus (GRSPaV), a member of the genus Foveavirus, is a commonly detected grapevine virus around the world....  相似文献   

Animal welfare standards for dairying and European Union consumer product safety rules     

Muller I 《Tijdschrift voor diergeneeskunde》2007,132(19):762

  相似文献   

Comparative evaluation of positive tests to Mycobacterium avium subsp. paratuberculosis in clinically healthy sheep and goats in south-west Greece using molecular techniques, serology, and culture     

Ikonomopoulos J  Balaskas C  Kantzoura B  Fragiadaki E  Pavlik I  Bartos M  Lukas JC  Gazouli M 《Veterinary journal (London, England : 1997)》2007,174(2):337-343

Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of paratuberculosis, which affects mainly ruminants although there is a growing concern about its possible implication in Crohn's disease in humans especially in connection with environmental spread and risks to the food chain. Retail cheese may represent a significant source of human exposure to MAP and the aim of this study was to assess MAP status in clinically healthy sheep and goats in Greece, comparing techniques routinely used in the positive diagnosis of the disease. From a total of 30 flocks, 632 sheep and goats had faecal, serum, and whole-blood samples examined by culture, complement fixation test (CFT), and polymerase chain reaction (PCR) targeted at IS900, IS1245, and IS6110. PCR produced positive results in 21% of the animals tested, with 5.6%, 3.9%, and 11.5% being identified as MAP, Mycobacterium avium subsp. avium, and Mycobacterium tuberculosis complex, respectively. CFT produced positive and suspicious results in 4.4% and 14.4% of the cases. Faecal cultures were negative in all but a single case that was identified as restriction fragment length polymorphism (RFLP)-type BC1. Agreement between results obtained by PCR and CFT was poor with isolated cases although an assessment of the MAP positive tests produced similar results for both methods. The findings indicate the need for additional measures of control, although the costs may be substantial if public health protection justifies elimination of MAP from livestock.  相似文献   

Formulation of an Alternative Culture Medium for Arthrospira maxima (Spirulina) Based on “Tequesquite,” a Traditional Mineral Resource          下载免费PDF全文

Fernando Martínez‐Jerónimo  Dante Ivo Flores‐Hernández  Juvencio Galindez‐Mayer 《Journal of the World Aquaculture Society》2017,48(6):887-897

Culture media formulation for Arthrospira maxima (formerly designated as Spirulina maxima) production is a constraining factor. Use of synthetic media could be expensive because most of the commercial strains require salinity conditions higher than 20 g/L. In this study, a traditional, pre‐Hispanic mineral resource, known as “tequesquite,” was used as the base for the formulation of an alternative and low‐cost culture medium. Tequesquite is available from outcrop areas located in the basin of the former Lake Texcoco, where A. maxima thrived in pre‐Hispanic times. The effect on the biomass production of different tequesquite‐based formulations, varying N, P, and , was tested and compared with results obtained with Zarrouk's medium (ZM). Growth of biomass in some alternative formulations showed no significant differences compared with ZM. Production in a bubble‐column photobioreactor of the alternative medium reached a maximum of X = 2570.4 mg/L dry weight, compared with X = 2931.4 mg/L dry weight obtained with ZM. The proposed tequesquite‐medium formulation has equivalent N and P concentrations as ZM, but only 50% of NaHCO₃, thus reducing the medium's cost. In addition, it avoids the use of seawater or NaCl to provide the salinity condition required for the adequate growth of Arthrospira.  相似文献   

Heat stress affects vegetative and reproductive performance and trait correlations in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)     

Jiemeng Xu  Mieke Wolters-Arts  Celestina Mariani  Heidrun Huber  Ivo Rieu 《Euphytica》2017,213(7):156

High ambient temperature has adverse effects on plant vegetative and reproductive development and reduces crop yield. To better understand the importance of male and female fertility for tomato fruit set ability under high temperature conditions and to test whether heat tolerance levels among and between reproductive and vegetative traits of genotypes correlate with each other, 13 tomato cultivars were subjected to long-term moderate heat (LTMH) or short-term heat shock (STHS), depending on the trait that was evaluated. LTMH caused significant decrease in performance of nearly all reproductive traits, i.e. pollen viability, pollen number, female fertility, seeded-fruit set and flower number per inflorescence, but not in inflorescence number. Considerable variation was found among cultivars, both under control and LTMH conditions. The cultivars Nagcarlang, Saladette and Malintka 101 produced a higher percentage of viable pollen under LTMH. For fruit set under LTMH condition, only cultivars that had been previously reported as being heat-tolerant produced fruits with seeds. STHS negatively affected vegetative traits concerning seedling survival and membrane stability. Correlation analysis revealed relationships between various traits within the control and heat treatments, but not between the two. Under heat stress fruit set was positively correlated with pollen viability, as well as with flower number per inflorescence. However, no significant correlations were found between vegetative and reproductive traits. Our data highlight the prominent role of pollen viability for tomato fertility under LTMH growth conditions. The observed variation in thermotolerance among different cultivars offers the possibility to decipher underlying physiological and genetic mechanisms.  相似文献   

Improving dairy production in Malawi: a literature review     

Ivo Baur  Léa Tabin  McLoyd Banda  Daniel Chiumia  Markus Lips 《Tropical animal health and production》2017,49(2):251-258

Milk production in Malawi is stagnating while steadily increasing in neighboring countries. We performed a literature review to identify factors negatively affecting milk production in Malawi and propose potential solutions to overcome the particular constraints. We structured the analysis along the value chain with three major components: upstream providers, on-farm production, and downstream providers. It is shown that the literature strongly focuses on on-farm constraints and most prominently on animal health, breed choice, and milk yield. The literature research did not reveal any reasons specific to Malawi that would hinder an increase in milk production as experienced in neighboring countries. We suggest a focus on crossbreeds accompanied by local breeding programs, which would reduce dependence on imported semen and strengthen the currently unreliable artificial insemination services. In addition, crossbreeds may be better suited than pure breeds for current feeding practices and climate conditions and thus come close to reaching their genetic potential. We conclude that cost advantages of crossbreeds clearly compensate for the lower revenues compared with exotic breeds such as Holstein-Friesian or Jersey.  相似文献   

Sequence variation and mRNA expression of the TWIST1 gene in cats with mammary hyperplasia and neoplasia     

Baptista CS  Santos S  Laso A  Bastos E  Avila S  Guedes-Pinto H  Gärtner F  Gut IG  Castrillo JL  Chaves R 《Veterinary journal (London, England : 1997)》2012,191(2):203-207

  相似文献   

Different immune response of pigs to Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis infection     

Stepanova H  Pavlova B  Stromerova N  Ondrackova P  Stejskal K  Slana I  Zdrahal Z  Pavlik I  Faldyna M 《Veterinary microbiology》2012,159(3-4):343-350

Mycobacterium avium subsp. avium (MAA) and Mycobacterium avium subsp. hominissuis (MAH) are the most common mycobacterial species isolated from granulomatous lesions in swine in countries with controlled bovine tuberculosis. This study is focused on the immunological aspect of MAA and MAH infection in pigs. We detected induction of humoral and cell-mediated immunity in experimentally infected pigs. Specific antibodies were analyzed in serum by ELISA and the IFN-γ release assay was used for evaluation of cell-mediated immunity. While MAA induced a significant increase of both types of immune responses, MAH-infected pigs had an unvarying level of specific antibodies and showed low cell-mediated immunity with high individual variability. The subsequent in vitro experiment confirmed the lower immunogenicity of the MAH strain in comparison to MAA. MAH-infected porcine monocyte-derived macrophages showed a weaker induction of pro-inflammatory mediators in comparison to MAA, which included mRNA for IL-1β, TNF-α, IL-23p19, IL-18 and chemokines CCL-3, CCL-5, CXCL-8 and CXCL-10. Additionally, qualitative proteomic analysis revealed 28 proteins exclusively in MAA and 7 proteins unique to MAH. In conclusion, closely related M. avium subspecies MAA and MAH showed different capacities to stimulate the porcine immune system. From a diagnostic point of view, the IFN-γ release assay showed higher sensitivity than the detection of specific antibodies by ELISA and seems to be an effective tool for discrimination of MAA-infected pigs. In the case of MAH infection, the IFN-γ release assay could fail because of the low immunogenic capacity of the MAH strain.  相似文献   

Characterisation of a 16SrII phytoplasma strain associated with bushy stunt of hawkweed oxtongue (Picris hieracioides) in south-eastern Serbia and the role of the leafhopper Neoaliturus fenestratus (Deltocephalinae) as a natural vector     

Milana Mitrovi?  Jelena Jovi?  Tatjana Cvrkovi?  Oliver Krsti?  Nenad Trkulja  Ivo To?evski 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(3):647-660

A 2-year study of host association, molecular characterisation and vector transmission of a phytoplasma related to the 16SrII group in a vineyard of south-eastern Serbia was conducted. Grapevine, eight common weeds and 31 Auchenorrhyncha species were collected and analysed for phytoplasma presence. PCR-RFLP analyses of the 16S rRNA gene identified the presence of a new strain of phytoplasma related to the 16SrII group in P. hieracioides with symptoms of stunting or bushy stunting. Grapevine samples, all without symptoms, were negative for phytoplasma presence. Plants of Erigeron annuus, Cynodon dactylon, Daucus carota and P. hieracioides, either exhibiting symptoms of yellowing or without symptoms, were positive for the presence of stolbur phytoplasma. Among the tested cicada species, seven were infected with phytoplasmas from the aster yellows group, two with stolbur phytoplasma, two with 16SrII phytoplasma, and one with the 16SrV-C phytoplasma subgroup. The phytoplasma strain of the 16SrII group was recorded in approximately 50?% of the collected leafhopper species Neoaliturus fenestratus and in a few specimens of the planthopper Dictyophara europaea. The vector status of N. fenestratus was tested using the second generation of the planthopper in two separate transmission trials with P. hieracioides and periwinkle seedlings. In both tests, the leafhopper successfully transmitted 16SrII phytoplasma to exposed plants, proving its role as a natural vector of this phytoplasma in Europe. A finer molecular characterisation and phylogenetic relatedness of the 16SrII phytoplasma strain by sequence analyses of the 16S rRNA and ribosomal protein genes rpl22-rps3 indicated that it was most closely related to the 16SrII-E subgroup.  相似文献