Molecular characterisation of quinolone resistance in Escherichia coli from animals in Turkey     

M Cengiz  S Sonal  E Buyukcangaz  A Sen  E Arslan  B Mat  P Sahinturk  H Gocmen 《The Veterinary record》2012,171(6):155

The aim of this study were to detect the gyrA, parC and marR mutations and qnr genes (qnrA, qnrB and qnrS) in 120 strains of Escherichia coli isolated from animals. European Committee on Antimicrobial Susceptibility Testing and Clinical Laboratory Standards Institute disc diffusion and minimum inhibitory concentration (MIC) tests, respectively, were used to determine fluoroquinolone (FQ) resistance, and molecular methods were used to detect the mutations and the genes. E coli isolates with an MIC of ≥8 mg/l had mutation at Ser-80 in parC in addition to mutations at Ser-83, Asp-87 or both in gyrA. The nucleotide change was detected in marR (Ser-3?→?Asn, Ala-53?→?Glu, Gly-103?→?Ser, Tyr-137?→?His). Only four E coli isolates (3.3 per cent) contained qnrA and qnrS, and qnrB was not detected. Two E coli isolates from healthy calves also contained qnrA and qnrS. The MICs of enrofloxacin and danofloxacin for qnr-containing E coli isolates ranged from 32 mg/l to 256 mg/l. The results of this study indicated that the FQ-resistant E coli isolates presented an alteration in gyrA (Ser-83?→?Leu, Asp-87?→?Asn) and parC (Ser-80?→?Ile) with high MICs (8-256 mg/l), and there was a low prevalence of qnr genes among E coli isolated from animals.  相似文献   

Steroid receptor mRNA expression in the ovarian follicles of cows with cystic ovarian disease     

Alfaro NS  Salvetti NR  Velazquez MM  Stangaferro ML  Rey F  Ortega HH 《Research in veterinary science》2012,92(3):478-485

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Anti-acetylcholinesterase, anti-α-glucosidase, anti-leishmanial and anti-fungal activities of chemical constituents of Beilschmiedia species     

Mollataghi A  Coudiere E  Hadi AH  Mukhtar MR  Awang K  Litaudon M  Ata A 《Fitoterapia》2012,83(2):298-302

Phytochemical investigation of Beilschmiedia alloiophylla has resulted in the isolation of one new alkaloid, 2-hydroxy-9-methoxyaporphine (1), and ten known natural products, laurotetanine (2), liriodenine (3), boldine (4), secoboldine (5), isoboldine (6), asimilobine (7), oreobeiline (8), 6-epioreobeiline (9), β-amyrone (10), and (S)-3-methoxynordomesticine (11). Chemical studies on the bark of B. kunstleri afforded compounds 2 and 4 along with one bisbenzylisoquinoline alkaloid, N-dimethylphyllocryptine (12). Structures of compounds 1-12 were elucidated on the basis of spectroscopic methods. All of these isolates were evaluated for their anti-acetylcholinesterase (AChE), anti-α-glucosidase, anti-leishmanial and anti-fungal activities. Compounds 1-12 exhibited strong to moderate bioactivities in aforementioned bioassays.  相似文献   

Comparative molecular marker-based genetic mapping of flavanone 3-hydroxylase genes in wheat,rye and barley     

E. K. Khlestkina  E. A. Salina  I. E. Matthies  I. N. Leonova  A. Börner  M. S. Röder 《Euphytica》2011,179(2):333-341

The F3 h gene encoding flavanone 3-hydroxylase, one of the key enzymes of the flavonoid biosynthesis pathway, is involved in plant defense response, however, it has not yet been genetically mapped in such important crop species as wheat, barley and rye. In the current study, the F3 h genes were for the first time genetically mapped in these species, using microsatellite and RFLP markers. The three wheat F3 h homoeologous copies F3 h-A1, F3 h-B1 and F3 h-D1, and rye F3 h-R1 were mapped close to the microsatellite loci Xgwm0877 and Xgwm1067 on chromosomes 2AL, 2BL, 2DL, and 2RL, respectively. Wheat F3 h-G1 and barley F3 h-H1 were also mapped at the homoeologous F3 h-1 position on chromosomes 2GL and 2HL, respectively. The non-homoeologous F3 h gene (F3 h-B2) was mapped on wheat chromosome 2BL about 40 cM distal to the F3 h-1 map position. The results obtained in the current study are important for further studies aimed on manipulation with F3 h expression (and, hence, plant defense) in wheat, barley and rye.  相似文献   

A comparison of the virulence of selected Pythium,Globisporangium, Phytopythium and Phytophthora species against strawberry plants     

Pánek  Matěj  Střížková  Ivana 《植物病害和植物保护杂志》2021,128(6):1447-1458

Journal of Plant Diseases and Protection - A total of twenty-five isolates of species Phytophthora cactorum, P. citrophthora, Pythium dissotocum complex, Py. aphanidermatum, Globisporangium...  相似文献   

Growth and rhizosphere P pools of legume–wheat rotations at low P supply     

Hasnuri Mat Hassan  Hasbullah Hasbullah  Petra Marschner 《Biology and Fertility of Soils》2013,49(1):41-49

Legume pre-crops may increase P uptake of the following wheat, but the mechanisms behind this effect are unclear. A rotation study was carried out to assess the concentrations of rhizosphere P pools of three grain legumes and wheat (phase 1) and their effects on P uptake and P pools in the rhizosphere of the following wheat (phase 2). Faba bean, chickpea, white lupin and wheat were grown for 10 weeks in a loamy sand soil with low P availability. The following wheat was grown in the pre-crop soil with and without addition of pre-crop residues. Among the pre-crops, white lupin had the strongest effect on the P pools; it depleted the labile P pools, resin P and NaHCO₃-Pi and also the less labile P pools, NaOH-Pi and residual P; whereas the concentration of NaHCO₃-Po was higher than that in the rhizosphere of the other pre-crops. White lupin had a smaller biomass compared to faba bean which depleted the P pools to a lesser extent. Phosphorus uptake of the following wheat was greatest in white lupin pre-crop soil. Chickpea increased P uptake of the following wheat when residues were added. In the presence of residues, wheat after legumes depleted labile P pools to a greater extent than wheat after wheat, but this coincided with greater P uptake only in wheat after chickpea and white lupin, which may be explained by the small root biomass of wheat after faba bean. The results show that the greater P uptake of the following wheat induced by pre-crops may be due to two mechanisms: P mobilisation (white lupin) or P addition with legume residues (chickpea). This study further showed that P uptake by a crop is only partly a function of the depletion of P in the rhizosphere; another important factor is the ability to exploit a large soil volume.  相似文献   

A new approach to water management of tropical peatlands: a case study from Malaysia     

H.P. Ritzema  Abd. Mutalib Mat Hassan  R.P. Moens 《Irrigation and Drainage Systems》1998,12(2):123-139

The use of peatlands in the humid tropics requires drainage to remove excess rainfall. The design principles for the drainage systems currently being implemented on peatlands are the same as for mineral soils. The objective of such systems is the timely removal of excess rainfall by surface runoff. For peatlands, with their different soil-hydraulic characteristics, these systems have resulted in poor watertable control and high rates of irreversible subsidence. Concerns about this rate of subsidence and the level of sustainability of the present land use have prompted a study to develop a new water management system. This new system includes a shift from a drainage system that focuses on discharge of excess water towards a system that combines drainage and water conservation. In the new two-step design, the drain spacing and corresponding drain discharges are obtained with a steady-state approach. These outputs are used to calculate the capacity of the drains, including control structures, using an unsteady-state approach. The new system results in a shallower but more narrowly spaced drainage system and maintains a more constant but relatively high watertable and reduces subsidence. It should be remembered however, that even with the improved water management, subsidence cannot be arrested; it is the price one has to pay for the use of tropical peatlands.  相似文献   

Experimental trial in heifers vaccinated with Staphylococcus aureus avirulent mutant against bovine mastitis     

Pellegrino M  Giraudo J  Raspanti C  Nagel R  Odierno L  Primo V  Bogni C 《Veterinary microbiology》2008,127(1-2):186-190

Staphylococcus aureus, is the most frequently isolated pathogen from cases of bovine mastitis. Vaccination against S. aureus seems to be a rational approach for the control of staphylococcal mastitis. In the present work we evaluate the response of heifers vaccinated with a S. aureus avirulent mutant to the intramammary challenge with a S. aureus virulent strain. Clinical signs, production of milk, shedding of S. aureus cells, somatic cell count (SCC) and antigen-specific IgG in blood and milk, were determined. Two subcutaneous doses of a culture of the mutant, used as vaccine, was administered to four pregnant heifers 30 and 10 days before calving. The vaccinated heifers and four non-vaccinated were challenged 10 days after calving with the homologous virulent S. aureus strain, which was inoculated by intramammary route into two quarters of each animal. No local tissue damage was observed due to the administration of the vaccine. A significantly increase of specific IgG to S. aureus RC122 was detected in blood and milk of vaccinate heifers as well as a slight increase in daily milk yield during the trial. No significant difference on shedding of bacteria in milk and SCC were found among groups. In conclusion, vaccination of heifers before calving by an avirulent mutant vaccine of S. aureus, induced specific and significant antibody responses and provide better post-challenge conditions in vaccinated heifers.  相似文献   

Inheritance,fitness costs,incomplete resistance and feeding preferences in a laboratory‐selected MON810‐resistant strain of the true armyworm Mythimna unipuncta          下载免费PDF全文

Matías García  Félix Ortego  Pedro Hernández‐Crespo  Gema P Farinós  Pedro Castañera 《Pest management science》2015,71(12):1631-1639

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Ingestion of food pellets containing Escherichia coli overexpressing the heat‐shock protein DnaK protects Penaeus vannamei (Boone) against Vibrio harveyi (Baumann) infection          下载免费PDF全文

S Sinnasamy  N Mat Noordin  T H MacRae  M Ikhwanuddin bin Abdullah  P Bossier  M E bin Abdul Wahid  A Noriaki  Y Y Sung 《Journal of fish diseases》2016,39(5):577-584

Feeding aquatic animals with bacterial encapsulated heat‐shock proteins (Hsps) is potentially a new method to combat vibriosis, an important disease affecting aquatic animals used in aquaculture. Food pellets comprised of shrimp and containing Escherichia coli overexpressing either DnaK‐DnaJ‐GrpE, the prokaryotic equivalents of Hsp70‐Hsp40‐Hsp20, or only DnaK were fed to juveniles of the white leg shrimp Penaeus vannamei, and protection against pathogenic Vibrio harveyi was determined. Maintaining pellets at different temperatures for varying lengths of time reduced the number of live adhering E. coli, as did contact with sea water, demonstrating that storage and immersion adversely affected bacterial survival and attachment to pellets. Feeding P. vannamei with E. coli did not compromise their survival, indicating that the bacteria were not pathogenic to shrimp. Feeding P. vannamei with pellets containing bacteria overproducing DnaK (approximately 60 cells g^?1 pellets) boosted P. vannamei survival twofold against V. harveyi, suggesting that DnaK plays a role in Vibrio tolerance. Pellets containing DnaK were effective in providing protection to P. vannamei for up to 2 weeks before loss of viability and that DnaK encapsulated by these bacteria enhanced shrimp resistance against Vibrio infection.  相似文献