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E. Escudero L. Vinué T. Teshager C. Torres M.A. Moreno 《Research in veterinary science》2010,88(1):83-87
Introduction
Fecal Escherichia coli isolates showing a phenotype of reduced susceptibility or resistance to extended-spectrum cephalosporins are common among pigs in Spain. The aim of this study was to describe the main beta-lactam resistance mechanisms carried by these strains and their distribution at farm-level.Materials and methods
Twenty-nine E. coli isolates showing reduced susceptibility or resistance to extended-spectrum cephalosporins were collected from a sampling frame of 80 pig farms distributed over 13 Spanish provinces. The survey was carried out at the slaughterhouse level in 2004.Results
Of the 29 isolates, 21 (72%) met the criteria for a positive phenotypic confirmatory test for extended-spectrum beta-lactamases (ESBL). The following ESBLs were detected: SHV-12 (12 isolates, 41%), CTX-M-1 (three isolates, 10%), CTX-M-9 (three isolates, 10%), and CTX-M-14 (three isolates, 10%). The remaining eight isolates (28%) were phenotypically non-ESBL, with seven of them (24%) showing mutations on the chromosomal ampC gene promoter at positions −42 (C → T), −18 (G → A), −1 (C → T), and +58 (C → T). A multiplex PCR for detection of plasmidic class C beta-lactamases was negative for all isolates.Conclusion
Different ESBLs and other mechanisms linked to extended-spectrum cephalosporin resistance are widely distributed among fecal E. coli from slaughter pigs in Spain. 相似文献3.
Luke Randall Katharina Heinrich Robert Horton Lucy Brunton Matthew Sharman Victoria Bailey-Horne Meenaxi Sharma Ian McLaren Nick Coldham Chris Teale Jeff Jones 《Research in veterinary science》2014
Waste milk samples from 103 farms in England and Wales were examined for the presence of β-lactam antibiotics and ESBL-producing Enterobacteriaceae. Approximately 10 months after the initial sampling, further waste milk, environmental and faecal samples from farms shown to be positive for CTX-M Escherichia coli were investigated further. Isolates with an ESBL phenotype were tested by PCR for the presence of blaCTX-M, blaOXA, blaSHV and blaTEM genes. Isolates positive for blaCTX-M were sequenced to determine CTX-M type. Representative isolates were further examined by PFGE, plasmid replicon typing and serotyping. Of particular interest, 21.4% of waste milk samples contained residues of the cephalosporin cefquinome, which was significantly associated with CTX-M bacteria. Such bacteria occurred in 5.8% of the waste milk samples (including 3.9% CTX-M E. coli). CTX-M types identified were 1, 14, 14b and 15, but none of the E. coli were serotype O25, the serotype of the human pandemic strain. 相似文献
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Adverse drug reactions in horses are rare. The antimicrobials are in the list of the most common drugs associated with reaction in horses. The aim of this report is to describe the clinical presentation of an adverse drug reaction after the intramuscular administration of ceftiofur hydrochloride. A 5-year-old crioulo broodmare at one day postpartum presented signs of difficulty to walk, positive pulse in the four limbs, and heart rate of 80 beats per minute (bpm), with a history of fighting with another mare. The clinical suspicions were rhabdomyolysis and laminitis. Initially a dose of flunixin meglumine was administrated intravenous to prevent an endotoxemia. On the same day, the blood collection showed an elevated number of white blood cells, predominantly neutrophils and monocytes. An antimicrobial treatment with ceftiofur hydrochloride at a dose of 2.2 mg/kg intramuscular was applied. At the first day, the mare does not show signs of drug side effect. However, 24 hours later, in the second application, the patient presents incoordination, dizziness, and loss of equilibrium. At the same time, dexamethasone was administrated. The signs were reverted, and the mare was normal after the reaction. The treatment with ceftiofur was changed to enrofloxacin, and the animal had a complete recovery. These drug reactions are not common in the routine of equine clinical practitioners, but they cause a great preoccupation for the owner and the veterinarian. 相似文献
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[目的]获得高产稳定的头孢菌素优良菌株。[方法]先经UV诱变处理深冷孢子液,再培养单菌落,经富集培养划菌落带,采用琼脂柱预筛选法,通过摇瓶初筛、复筛及斜面传代单菌落菌型考察,研究琼脂柱预筛选法在头孢菌素菌种选育中的应用价值及稳定性。[结果]与单菌落分离直接摇瓶筛选法相比,采用琼脂柱预筛选法筛选单菌落省时、省力,效果好。经琼脂柱预筛选法获得的菌株性能稳定,摇瓶效价平均值高,F1、F2、F3、F4代的摇瓶效价分别高出对照16.7%、33.3%、16.0%、12.0%,其中F2代斜面可确认为生产用斜面。[结论]应用琼脂柱预筛选法进行菌种选育,可提高筛选效率和数量,增加高产菌株的获得几率,缩短筛选时间。 相似文献
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