Biosynthesis of Depsipeptide Mycotoxins in Fusarium     

Till Hornbogen  Mirko Glinski  Rainer Zocher 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(7):713-718

The cyclic hexadepsipeptide enniatin is known as a phytopathogenic compound from Fusaria causing necrosis and wilt. The molecule consists of three alternating residues each of a branched chain amino acid and D-hydroxyisovaleric acid (D-Hiv). Enniatins are synthesized by a 347kDa multienzyme (enniatin synthetase) via a thiol template mechanism. The corresponding gene esyn1 has an open reading frame of 9393 nucleotides and harbours two modules, one responsible for D-hydroxy acid activation and one for L-amino acid activation with an integrated N-methyltransferase domain. Such methyltransferases build an homologous group among N-methyl peptide synthetases. Enniatins are synthesized by step-wise condensation of dipeptidol building blocks in an iterative manner resembling fatty acid synthesis. A key enzyme in enniatin biosynthesis is the NADPH-dependent D-2-hydroxyisovalerate dehydrogenase, that supplies enniatin synthetase with D-Hiv. Enniatins contribute to the wilt toxic character of Fusaria. Virulence was significantly reduced in F. avenaceum after disruption of the esyn1 gene.  相似文献   

The Effect of Inoculation Treatment and Long-term Application of Moisture on Fusarium Head Blight Symptoms and Deoxynivalenol Contamination in Wheat Grains     

Marc Lemmens  Hermann Buerstmayr  Rudolf Krska  Rainer Schuhmacher  Heinrich Grausgruber  Peter Ruckenbauer 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(3):299-308

Fusarium head blight (FHB) is an important disease of wheat, which can result in the contamination of grains with mycotoxins such as deoxynivalenol (DON). Artificial inoculation of flowering ears with conidial suspensions is widely used to study FHB diseases. Our goal was to compare four inoculation treatments in which a conidial suspension was sprayed on flowering ears and to study the effect of the application of moisture during kernel setting and filling with a mist-irrigation system. Ten wheat genotypes were inoculated with a DON-producing Fusarium culmorum strain. Inoculation treatments varied in time of application of the inoculum (morning or evening) and in the method of controlling humidity during inoculation (bagging or mist irrigation). A wet season was simulated with a mist-irrigation system, keeping the crop canopy wet for at least 26 days after flowering. The severity of FHB symptoms (area under disease progress curve (AUDPC)), yield loss and DON contamination in the grains were determined. AUDPC data obtained with the different inoculation treatments were highly correlated (r=0.85–0.95). Mist irrigation after inoculation resulted in a higher mean disease severity, but in a overall lower toxin contamination as compared to the non-irrigated treatments. Genotypic differences in DON accumulation were present: for one wheat line toxin contamination significantly increased when irrigated, while two genotypes accumulated significantly less toxin. The closest relationships (r=0.73–0.89) between the visual symptoms and the DON content were obtained under moderate mean infection pressure. This relation between visual symptoms and the DON content deteriorated at higher infection levels.  相似文献   

Short- and long-term outcome in cats diagnosed with pyothorax: 47 cases (2009-2018)     

F. Krämer  J. Rainer  M. S. Bali 《The Journal of small animal practice》2021,62(8):669-676

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Ultrasonographic evaluation of the width,thickness, and length of the normal linea alba in standing and dorsal recumbent horses     

Maria E. Verkade  Joanna Suthers  Peter Wiemer  Ann Martens  Eva De Clercq  John Burford 《Veterinary surgery : VS》2021,50(1):158-169

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Magnetic Resonance Imaging of the Dorsal Proximal Synovial Plica of the Equine Metacarpo‐/Metatarsophalangeal Joint          下载免费PDF全文

S. Hauspie  K. Vanderperren  I. Gielen  B. Pardon  K. Kromhout  A. Martens  J. H. Saunders 《Anatomia, histologia, embryologia》2016,45(1):19-27

A synovial plica is present at the dorsoproximal aspect of the fetlock joint. The objective of this study was to describe the location of the synovial plica during induced hyperextension using Magnetic Resonance Imaging. For this study 20 cadaver limbs from five Warmblood horses were used. Measurements were made of the dorsal; palmar/plantar length and the thickness of the plica with the joint in a normal position. During induced hyperextension of the joint, the position of the plica was described; the dorsal angle of extension and angle of contact between the proximal phalanx (P1) and the condyle were measured. The dorsal length differed between front/hind limbs and between the medial/lateral aspect of the joint. The angle of contact between P1 and condyle differed between front/hind limbs; between the lateral and medial aspect of the joint and between different positions of the plica. Four different positions of the plica were observed: shortened with the tip curved towards palmar/plantar; projecting distally; projecting towards dorsal and projecting distally with the tip interposed between P1 and the condyle. During induced hyperextension, a close relation is present between the synovial plica, P1 and the condyle with a variable position of the plica; which is suggestive for a contact interface between P1 and the metacarpal/metatarsal bone. However the plica does not seem to act consistently as a cushioning surface.  相似文献   

Evaluation of a combined transcutaneous carbon dioxide pressure and pulse oximetry sensor in adult sheep and dogs     

Vogt R  Rohling R  Kästner S 《American journal of veterinary research》2007,68(3):265-270

OBJECTIVE: To evaluate a combined transcutaneous carbon dioxide pressure (tcPCO(2)) and pulse oximetry sensor in sheep and dogs. ANIMALS: 13 adult sheep and 11 adult dogs. PROCEDURES: During inhalation anesthesia, for the first 10 minutes following sensor placement, arterial blood gas was analyzed and tcPCO(2) was recorded every 2 minutes. Subsequently, the animals were hyper-, normo-, and hypoventilated. The simultaneously obtained tcPCO(2) and PaCO(2) values were analyzed by use of Bland-Altman statistical analysis. RESULTS: Mean +/- SD overall difference between tcPCO(2) and PaCO(2) 10 minutes after sensor application was 13.3 +/- 8.4 mm Hg in sheep and 8.9 +/- 12 mm Hg in dogs. During hyper-, normo-, and hypoventilation, mean difference (bias) and precision (limits of agreement [bias +/- 2 SD]) between tcPCO(2) and PaCO(2) values were 13.2 +/- 10.4 mm Hg (limits of agreement, -7.1 and 33.5 mm Hg) in sheep and 10.6 +/- 10.5 mm Hg (limits of agreement, -9.9 and 31.2 mm Hg) in dogs, respectively. Changes in PaCO(2) induced by different ventilation settings were detected by the tcPCO(2) sensor with a lag (response) time of 4.9 +/- 3.5 minutes for sheep and 6.2 +/- 3.6 minutes for dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The tcPCO(2) sensor overestimated PaCO(2) in sheep and dogs and followed changes in PaCO(2) with a considerable lag time. The tcPCO(2) sensor might be useful for noninvasive monitoring of changes but cannot be used as a surrogate measure for PaCO(2).  相似文献   

Broad range 16S rRNA gene PCR compared to bacterial culture to confirm presumed synovial infection in horses     

Pille F  Martens A  Schouls LM  Dewulf J  Decostere A  Vogelaers D  Gasthuys F 《Veterinary journal (London, England : 1997)》2007,173(1):73-78

The objectives of the present study were to evaluate the accuracy of broad range 16S rRNA gene PCR compared to bacterial culture for the detection of synovial infection in horses. The study included 57 synovial fluid samples from horses with presumed synovial infection and a control group consisting of 31 synovial fluid samples originating from clinically normal horses and horses with aseptic synovial inflammation. All samples were analysed by 16S PCR with reverse line blot (RLB) hybridisation. Synovial fluid samples were cultured using conventional agar plate methods (APM) and/or blood culture medium (BCM). The results of the study showed a superior detection rate (89.5%) for 16S PCR with RLB. Bacterial culture had lower sensitivity, but highly acceptable detection rates (77.6%) were observed using BCM. APM had very low sensitivity (37.8%) and infection was never detected by plate isolation without positive incubation in BCM. The highest sensitivity (91.8%) for the detection of synovial infection was achieved when the results of incubation in BCM and 16S PCR were combined. For all the tests, the specificity was higher than 90%.  相似文献   

Norway and black rats in Europe: potential reservoirs for zoonotic arthropod‐borne pathogens?     

Anna Obiegala  Elisa Heuser  Ren Ryll  Christian Imholt  Johanna Fürst  Lisa‐Marie Prautsch  Anita Plenge‐Bnig  Rainer G Ulrich  Martin Pfeffer 《Pest management science》2019,75(6):1556-1563

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Microbial use of organic amendments in saline soils monitored by changes in the C/C ratio     

Khalid S. Khan  Andreas Gattinger  Franz Buegger  Michael Schloter  Rainer Georg Joergensen   《Soil biology & biochemistry》2008,40(5):1217-1224

An incubation experiment was carried out to investigate whether salinity at high pH has negative effects on microbial substrate use, i.e. the mineralization of the amendment to CO₂ and inorganic N and the incorporation of amendment C into microbial biomass C. In order to exploit natural differences in the ¹³C/¹²C ratio, substrate from two C₄ plants, i.e. highly decomposed and N-rich sugarcane filter cake and less decomposed N-poor maize leaf straw, were added to two alkaline Pakistani soils differing in salinity, which had previously been cultivated with C₃ plants. In soil 1, the additional CO₂ evolution was equivalent to 65% of the added amount in the maize straw treatment and to 35% in the filter cake treatment. In the more saline soil 2, the respective figures were 56% and 32%. The maize straw amendment led to an identical immobilization of approximately 48 μg N g⁻¹ soil over the 56-day incubation in both soils compared with the control soils. In the filter cake treatment, the amount of inorganic N immobilized was 8.5 μg N g⁻¹ higher in soil 1 than in soil 2 compared with the control soils. In the control treatment, the content of microbial biomass C₃-C in soil 1 was twice that in soil 2 throughout the incubation. This fraction declined by about 30% during the incubation in both soils. The two amendments replaced initially similar absolute amounts of the autochthonous microbial biomass C, i.e. 50% of the original microbial biomass C in soil 1 and almost 90% in soil 2. The highest contents of microbial biomass C₄-C were equivalent to 7% (filter cake) and 11% (maize straw) of the added C. In soil 2, the corresponding values were 14% lower. Increasing salinity had no direct negative effects on microbial substrate use in the present two soils. Consequently, the differences in soil microbial biomass contents are most likely caused indirectly by salinity-induced reduction in plant growth rather than directly by negative effects of salinity on soil microorganisms.  相似文献   

Biochemical and toxicological differences in the modes of action of the benzoylureas     

Rainer Neumann  Walter Guyer 《Pest management science》1987,20(2):147-156

The two insecticidal benzoylurea compounds, diflubenzuron and chlorfluazuron, show large differences in their toxicity against the larvae of insects like the tobacco budworm, Heliothis virescens, or the Egyptian cotton leafworm, Spodoptera littoralis, chlorfluazuron being about 100 times more toxic. This difference is due mainly to a much faster metabolism of diflubenzuron. Its half-life within the larvae is about 5 h, compared to about 50 h for chlorfluazuron. Chlorfluazuron is also the much better ovicide of the two, following injection of the compounds into the females of H. virescens. Again the difference in the rate of metabolism is the main cause. The rate of excretion of the parent benzoylureas is relatively low, but their metabolites are excreted very quickly.  相似文献