High prevalence of chlamydial (Chlamydophila psittaci) infection in fetal membranes of aborted equine fetuses     

Szeredi L  Hotzel H  Sachse K 《Veterinary research communications》2005,29(Z1):37-49

Seventy-seven cases of equine abortion from 49 Hungarian farms that occurred between 1998 and 2000 were investigated for the presence of chlamydiae by immunohistochemistry, PCR and/or MZN staining. Evidence of the presence of these bacteria was obtained in 64 cases (83.1%) from 41 (83.7%) different farms. Partial ompA gene sequencing of PCR products revealed that the agent was Chlamydophila psittaci. Based on the findings of microbial diagnosis, pathology and case history, chlamydial infection was considered to be the most likely cause of abortion in at least 11 (14.3%) cases. In the remaining 53 Chlamydophila-positive cases, either other bacterial and viral agents (n = 22 or 28.6%) as well as non-infectious factors (n = 14 or 18.2%) were identified as more probable primary causes of disease, or the role of chlamydiae remained unclear because lesions in fetuses and fetal membranes were absent (n = 17 or 22.1%). When chlamydial antigen was detected in aborted equine placental tissue using immunohistochemistry it was seen only in the chorionic epithelial cells, but not in other parts of the fetal membranes nor in any of the fetal tissues. In conclusion, chlamydial infection of the genital tract should be considered a possible factor in equine reproductive disorders.  相似文献   

The dual role of wild phages for horizontal gene transfer among Salmonella strains     

Rabsch W  Mirold S  Hardt WD  Tschäpe H 《Berliner und Münchener tier?rztliche Wochenschrift》2002,115(9-10):355-359

Salmonella bacteriophages seem to mediate horizontal transfer of virulence functions among Salmonella strains in two different ways: by general transduction and also by lysogenic conversion. The majority of wild phages isolated from Salmonella strains belong to the P22 like phages and were able to transduce. Our data show that the lysogenic conversion is generally accompanied by changes in the susceptibility to the typing phages used for epidemiological purposes. Similar phage type conversions to S. Typhimurium DT104 could be detected upon lysogenization with two other S. Typhimurium strains. For some S. Typhimurium strains the typical phage pattern is actually associated with alterations of virulence characteristics. For example, all tested wild type isolates of phage types DT49 and DT204 were found to be SopE phi-lysogens. The Anderson typing phages interfere with the prophages and/or cryptic phages and so the complex genetic short-term evolution can be demonstrated in the lab. This is one reason for the successful application of phage typing in Salmonella epidemiology since the 50s.  相似文献   

Untersuchungen zum Artenspektrum von Fusarium-Pilzen im Erntegut von Getreide im Land Brandenburg     

Cornelia Müller  Helmut Bröther 《Gesunde Pflanzen》2002,54(2):33-37

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Mycobacterium gordonae as potential cause of granulomatous lesions of the toe tips in the South African clawed frog (Xenopus laevis)     

Kirsch P  Nusser P  Hotzel H  Moser I 《Berliner und Münchener tier?rztliche Wochenschrift》2008,121(7-8):270-277

During regular health status monitoring of the colony of amphibian, Mycobacterium (M.) gordonae were isolated from granulomatous lesions of the tiptoes from the South African clawed frog (Xenopus laevis) maintained at the Tierforschungszentrum of the University of Ulm. During a period of three years a total of 21 animals of the colony, consisting of 350-400 frogs, showed granuloma of the tip of the toes and a loss of the claws. The general condition and the behavior of the frogs appeared to be unchanged. Using a selective medium one isolate was cultured and identified by sequencing of the 16S rRNA gene. To apply a rapid diagnostic method for detecting mycobacteria, in particular M. gordonae in the health monitoring programme of the Xenopus laevis colony, we established the rpoB gene PCR followed by HaeIII restriction analysis of the PCR product. We identified M. gordonae from granuloma of the tiptoes and from unaltered tissue samples of the lungs and skin by PCR restriction analysis. Since mycobacterial species apparently are widespread in granulomatous lesions of the tiptoes of Xenopus laevis, we hypothesize a pathogenic potential. This view is supported by an increasing number of reports in the literature on infections with nontuberculous, "non-pathogenic" mycobacteria in Xenopus laevis.  相似文献   

A survey of equine abortion and perinatal foal losses in Hungary during a three-year period (1998-2000)     

Szeredi L  Tenk M  Jánosi S  Pálfi V  Hotzel H  Sachse K  Pospischil A  Bozsó M  Glávits R  Molnár T 《Acta veterinaria Hungarica》2008,56(3):353-367

Cases of equine abortion and perinatal foal losses were investigated in Hungary during a three-year period (1998-2000). Samples from aborted equine fetuses and newborn foals (total n = 96) were examined using bacteriological, virological, pathological, immunohistochemical (IHC), molecular biological and serological methods. The cause of abortion and perinatal foal loss was identified in 67/96 cases (70%); viral infection was found in 22 (23%), viral and bacterial coinfection in 1 (1%), bacterial infection in 23 (24%), protozoan infection in 1 (1%) and fungal infection in 2 cases (2%). Morphological lesions suggestive of infection were recorded in 2 (2%) and non-infectious causes in 16 cases (17%).  相似文献   

Global proteomics analysis of testis and ovary in adult zebrafish (Danio rerio)     

Groh KJ  Nesatyy VJ  Segner H  Eggen RI  Suter MJ 《Fish physiology and biochemistry》2011,37(3):619-647

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Small-scale effects of historical land use and topography on post-cultural tree species composition in an Alpine valley in southern Switzerland   总被引：1，自引：0，他引：1  

Sina Muster  Helmut Elsenbeer  Marco Conedera 《Landscape Ecology》2007,22(8):1187-1199

Investigations of spatial patterns in forest tree species composition are essential in the understanding of landscape dynamics, especially in areas of land-use change. The specific environmental factors controlling the present patterns, however, vary with the scale of observation. In this study we estimated abundance of adult trees and tree regeneration in a Southern Alpine valley in Ticino, Switzerland. We hypothesized that, at the present scale, spatial pattern of post-cultural tree species does not primarily depend on topographic features but responds instead to small-scale variation in historical land use. We used multivariate regression trees to relate species abundances to environmental variables. Species matrices were comprised of single tree species abundance as well as species groups. Groups were formed according to common ecological species requirements with respect to shade tolerance, soil moisture and soil nutrients. Though species variance could only be partially explained, a clear ranking in the relative importance of environmental variables emerged. Tree basal area of formerly cultivated Castanea sativa (Mill.) was the most important factor accounting for up to 50% of species’ variation. Influence of topographic attributes was minor, restricted to profile curvature, and partly contradictory in response. Our results suggest the importance of biotic factors and soil properties for small-scale variation in tree species composition and need for further investigations in the study area on the ecological requirements of tree species in the early growing stage.  相似文献   

Metabolic phenotyping of mouse mutants in the German Mouse Clinic     

Ralf ELVERT  Nicole EHRHARDT  Martin TAUBE  Martin KLINGENSPOR  Valerie GAILUS‐DURNER  Helmut FUCHS  Martin Hrabe DE ANGELIS  Veronique BLANQUET  Gerhard HELDMAER 《Integrative zoology》2006,1(3):122-125

The German Mouse Clinic was established as a phenotyping center to provide the scientific community with systematic standardized phenotyping of mouse models from various genetic backgrounds. We found metabolic phenotypes in nine out of 20 mutant lines screened in a primary screen. Based on these findings, the mutants were analyzed in secondary and tertiary screens. Mice of a sample mutant line, isolated from the ENU‐screen at the National Research Center for Environment and Health in Munich, were found to have lower body weight, consume less food, but have higher ratios of metabolized energy per unit body weight compared with their wild‐type littermates. Basal metabolic rate and heat production were simultaneously increased by 16–18%, whereas body fat content was reduced by 11–16%. The combination of various parameters of energy consumption, expenditure and energy storage illustrate the metabolic demands of the sample mutant mouse line and demonstrate the utility of the powerful phenotyping tool used at the German Mouse Clinic.  相似文献   

Productivity is a poor predictor of plant species richness   总被引：5，自引：0，他引：5  

Adler PB  Seabloom EW  Borer ET  Hillebrand H  Hautier Y  Hector A  Harpole WS  O'Halloran LR  Grace JB  Anderson TM  Bakker JD  Biederman LA  Brown CS  Buckley YM  Calabrese LB  Chu CJ  Cleland EE  Collins SL  Cottingham KL  Crawley MJ  Damschen EI  Davies KF  DeCrappeo NM  Fay PA  Firn J  Frater P  Gasarch EI  Gruner DS  Hagenah N  Hille Ris Lambers J  Humphries H  Jin VL  Kay AD  Kirkman KP  Klein JA  Knops JM  La Pierre KJ  Lambrinos JG  Li W  MacDougall AS  McCulley RL  Melbourne BA  Mitchell CE  Moore JL  Morgan JW  Mortensen B 《Science (New York, N.Y.)》2011,333(6050):1750-1753

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters(-2)) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.  相似文献   

Human appropriation of net primary production     

Haberl H  Krausmann F  Erb KH  Schulz NB 《Science (New York, N.Y.)》2002,296(5575):1968-9; author reply 1968-9

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