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991.
992.
Zusammenfassung Die Nachkommenschaften eines Diallels mit 10 Eltern, ohne reziproke Kreuzungen, wurden gegen Pathotyp 1 (Dl) des Kartoffelkrebses geprüft. Aufgrund der Aufspaltung in resistent und anf?llig lassen sich 5 genotypische Gruppen unterscheiden. Zwei Gruppen entsprechen in ihrer Resistenzvererbung dem einfaktoriellen Modell bei Autotetraploiden auf duplexer bzw. simplexer Basis. Der Nachweis von zwei weiteren Genotypen, die sich nicht einordnen lassen, l?\t eine h?here genetische Varianz erkennen, als nach dem autotetraploiden Modell theoretisht zu erwarten ist. Die M?glichkeit der Identifizierung weiterer Genotypen wird nicht ausgeschlossen.
Summary The progeny of a diallel cross between 10 clones of table potatoes were tested for resistance toSynchytrium endobioticum Pathotype 1. Of the 10 parent clones, 9 were resistant, based on the characteristic defence necrosis, and one was very susceptible. In total 45 hybrid and 10 selfed progenies were tested with 60–100 genotypes in each case. The mean performance of each clone was assessed using the percentages of resistant genotypes for all 9 combinations with other clones, and the selfs. The 10 clones are arranged in Table 1 according to their rankings for this parameter. Five groups of genotypes (I–V) can be recognized; these are significantly different from one another. The mean values of the selfs for individual groups, and the combinations with the susceptible parent are also given. From these results it can be concluded that the clones in Groups I–III inherited resistance as if controlled by a single major dominant gene in the simplex or duplex condition in the autotetraploid. The susceptible parent gave a nulliplex-type. The corresponding test results given in Table 2 confirm these conclusions. According to Table 1, clones (4) and (9) do not fit into Groups I and III. They have another genotype. Since the parents used here cover only a small range of possible genotypes, no generally valid statements can be made about the number of groups and the frequency of the genotypes in the groups for all cultivars and clones ofSolanum tuberosum. Inheritance studies of wart resistance by other authors confirm the assumption that further genotype groups may be identified. Greater genetic variation can be expected than is theoretically possible in the single factor model of autotetraploidy.
  相似文献   
993.
Avian pathogenic Escherichia coli (APEC) are often found in poultry and are responsible for a set of diseases, commonly referred to as avian colibacillosis. One of the important virulence factors is adhesion to different epithelial surfaces, which is mediated by pili. P pili are thought to play a role by means of their PapG adhesin, which occurs in three molecular variants: PapGI, PapGII and PapGIII. This study is the first to determine and analyse the distribution of the different papG alleles in APEC. Our results show a significant predominance of the papGII allele above all other alleles or allele combinations. No statistically significant associations could be found between papG allele distribution and the type of bird, organ of isolation and O serogroup. Finally, the papGII and papGIII sequences showed high homology with mammalian (including human) source papG sequences.  相似文献   
994.
995.
Background: While screening programs have reduced the risk of infectious disease transmission by donors in human and veterinary blood banking, bacterial contamination of blood products has emerged as a major complication in human medicine. Objectives: To describe a Pseudomonas fluorescens (Pf)‐contaminated feline packed RBC (pRBC) unit and experimentally investigate Pf‐contaminated canine pRBCs. Methods: Canine pRBCs were inoculated with Pf‐rich pRBCs from the sentinel feline unit and stored at 4°C or 20°C for 72 hours. Aliquots from the pRBCs were serially evaluated by microscopy, culture, and a eubacterial 16S rRNA real‐time PCR assay. Results: One Pf‐contaminated feline unit turned black after 22 days of storage and was removed from the blood bank; a source was not found, and no other contaminated units were identified. Canine pRBCs spiked with 5 or 25 μL of the sentinel unit became culture‐ and/or 16S PCR‐positive at ≥8 hours at 20°C and 48 hours at 4°C and developed a color change at ≥24 hours. Sensitivity studies indicated that without incubation, inoculation of ≥100 μL Pf‐rich pRBCs was necessary for a positive 16S PCR test result. Conclusions: P. fluorescens grows in stored pRBCs slowly at 4°C and rapidly at 20°C. Screening of blood products for color change, estimating bacterial concentration with microscopy, and 16S PCR testing are simple and fast ways to detect bacteria in stored blood. Aseptic collection, temperature‐controlled storage, and regular visual monitoring of stored units is recommended. Discolored units should not be transfused, but examined for bacterial contamination or other blood product quality problems.  相似文献   
996.
The sites of oestrogen action can be shown by the localisation of their receptors in the target tissues. The aim of the present study was to show the localisation of oestrogen receptors in porcine embryos and fetuses obtained on days 18, 22, 32, 40, 50, 60, 71 and 90 post coitum (p.c.). The visualisation of proteins was conducted in embryos and various fetal organs such as gonads, uterus, lung, kidney, intestine and adrenal gland. Both ERs were observed in the blastocysts on day 18 p.c. In the male, ERbeta was detected in the testis and epididymis, whereas ERalpha was present in the efferent ductules. In the female, ERbeta was detected in the ovarian stromal cells investing the oocyte nests, while ERalpha protein was detected in the surface epithelium. In the uterus, ERs were present in the stromal cells, while ERbeta was present in the luminal epithelium. In the non-reproductive fetal porcine tissues ERbeta was localised in the lungs, kidneys, adrenal glands and in the umbilical cords. Both ERs were observed in the intestine. It is possible that ERbeta may play important roles in the development of the adrenal gland, testis, kidney and lungs, while both ERs are involved in the development of the ovary, uterus, epididymis and intestine of the porcine fetus.  相似文献   
997.
Only limited information is available on the epidemiology and pathogenesis of Bovine Herpesvirus 1 (BoHV-1) in domestic buffalos. In this study, a virulent BoHV-1 field strain isolated from cattle was inoculated into buffaloes to evaluate their susceptibility to the virus and to investigate the establishment of viral latency through clinical, virological and serological investigations. Latency was also studied by attempting viral reactivation using pharmacological induction. Six of seven male, 5 months old buffaloes were intranasally inoculated with BoHV-1; the other animal was kept as negative control. The animals were clinically monitored during the post-infection (P.I.) and the post-pharmacological induction (P.P.) periods. During these periods, nasal and rectal swabs, and blood samples, with and without anticoagulant, were collected at 2–3 day intervals. On culling the animals, 206 days P.I., their trigeminal ganglia and tonsils were collected. No clinical signs referable to BoHV-1 were observed throughout the experimental period. However, seropositivity was detected in all infected animals within day 20 P.I., using BoHV-1 glycoprotein E and glycoprotein B competitive ELISAs (IDEXX) and virus neutralisation test. In real-time PCR (RT-PCR), five of these animals were positive, at least once, for nasal or rectal swabs, during the P.I. period. The sixth infected animal was found positive only in the trigeminal ganglia after culling. Ganglia were also positive for two other animals. Virus isolation in permissive cell-lines was successful for a part of the RT-PCR positive samples. The detected viruses were confirmed by genetic analysis as identical to the inoculated strain. No evidence of infection was observed in the negative control. This study represents the first experimental transmission of BoHV-1 in buffaloes, confirming their susceptibility to infection and their possible role as host/reservoirs of BoHV-1.  相似文献   
998.
Nowadays, lamb meat represents only 7% of all meat produced in the world. In recent years the demand for standardized lamb meat cuts has been considered of great importance and the marketing occurs predominantly in the form of frozen cuts. Herewith, the main of this work was to evaluate the stability and safety of lamb meat during frozen storage. Meats were vacuum packed in high barrier multilayer plastic iflms and stored during 12 mon at (-18±1)℃. The meat stability was assessed by physical and chemical (lipid oxidation, objective color, pH value, cooking losses and instrumental texture), microbiological (total count of psychrotrophic, coliform count at 45℃, coagulase-positive staphylococci and the presence of Salmonella) and sensory analysis (acceptance test and visual evaluation). The vacuum packed lamb meat remained stable as to most physical and chemical indexes. Microbiological indexes showed good stability throughout the storage period according to Brazilian legislation standards to pathogenic microorganisms. Although a signiifcant reduction in tenderness (shear force increase from 3 to 8 kg), it showed a good sensorial acceptance for all attributes tested, including texture, with scores of around 7 (like moderately) during the 12 mon of storage. Therefore, it can be concluded that, under the conditions applied in this study, lamb meat presents a shelf life of at least 12 mon when stored at-18℃.  相似文献   
999.
Bungowannah virus is the most divergent atypical pestivirus that had been detected up to now, and does not fit into any of the four approved species: Bovine viral diarrhea virus type 1 (BVDV-1) and type 2 (BVDV-2), Classical swine fever virus (CSFV) and Border disease virus (BDV). However, the presence of Npro and Erns coding regions, which are unique to pestiviruses, provides clear evidence of a pestivirus. Nevertheless, the amino acid identity of Bungowannah virus Npro and BVDV-1 Npro (strain CP7) is only 51.5%. By using a BVDV-1 backbone, a novel chimeric construct was generated, in which the genomic region encoding the non-structural protein Npro was replaced by that of Bungowannah virus (CP7_Npro-Bungo). In vitro studies of CP7_Npro-Bungo revealed autonomous replication with the same efficacy as the BVDV backbone CP7 and infectious high-titer virus could be collected. In order to compare the ability of interferon (IFN) suppression, two reporter gene assays, specific for type-I IFN, were carried out. In virus-infected cells, no significant difference in blocking of IFN expression between the parental virus CP7, Bungowannah virus and the chimeric construct CP7_Npro-Bungo could be detected. In contrast, an Npro deletion mutant showed an impaired replication in bovine cells and a marked type-I IFN response.Taken together, our findings reveal the compatibility of non-structural protein Npro of atypical Bungowannah virus with a BVDV type 1 backbone and its characteristic feature as an inhibitor of type-I IFN induction with an inhibitor-activity comparable to other pestiviruses.  相似文献   
1000.
COVID-19 pandemic is essentially a zoonotic disease. In this context, early in 2020, transmission from humans to certain animals began reporting; the number of studies has grown since. To estimate the pooled prevalence of SARS-CoV-2 natural infection in animals and to determine differences in prevalence between countries, years, animal types and diagnostic methods (RT-PCR or serological tests). A systematic literature review with meta-analysis using eight databases. Observational studies were included but analyzed separately. We performed a random-effects model meta-analysis to calculate the pooled prevalence and 95% confidence interval (95% CI) for prevalence studies and case series. After the screening, 65 reports were selected for full-text assessment and included for qualitative and quantitative analyses. A total of 24 reports assessed SARS-CoV-2 infection by RT-PCR, combining a total of 321,785 animals, yielding a pooled prevalence of 12.3% (95% CI 11.6%–13.0%). Also, a total of 17 studies additionally assessed serological response against SARS-CoV-2, including nine by ELISA, four by PRTN, one by MIA, one by immunochromatography (rest, two studies, the method was not specified), combining a total of 5319 animals, yielding a pooled prevalence of 29.4% (95% CI 22.9%–35.9%). A considerable proportion of animals resulted infected by SARS-CoV-2, ranking minks among the highest value, followed by dogs and cats. Further studies in other animals are required to define the extent and importance of natural infection due to SARS-CoV-2. These findings have multiple implications for public human and animal health. One Health approach in this context is critical for prevention and control.  相似文献   
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