Clarke D.B.,UK Environment Agency
Analytical Methods | Year: 2010
Glucosinolates (GLS) are sulfur rich, anionic secondary metabolites found principally in the plant order Brassicales. This review focuses on identifying the range of GLS structures identified to date and summarises the current state of taxonomic reclassifications of GLS producing plants. Those Brassica species that are available to growers in the UK are highlighted and progress in the aspects of analytical chemistry relevant to conducting accurate determinations of GLS content of foods is reviewed. The degradation and derivatisation workflows that have been utilized for conducting "glucosinolate analysis" are summarized. A review is made of aspects of extraction, isolation, determination of purity, ultraviolet (UV) and mass spectrometry (MS) parameters, extinction coefficients, UV response factors, quantification procedures, and the availability of stable isotope labeled internal standards, and certified reference materials. An electronic database of structures, formulae and accurate masses of both the 200 known, and a further 180 predicted GLS, is provided for use in mass spectrometry. © 2010 The Royal Society of Chemistry.
Taylor M.A.,UK Environment Agency
Small Ruminant Research | Year: 2010
Sheep are parasitised by a diverse range of internal and external parasites. The majority of adult helminths and many of the ectoparasites affecting sheep, are grossly visible to the naked eye due to their size. With internal parasites, however, observation and detection of adult stages is generally only possible on post-mortem examination of the appropriate organs and viscera. More often, the presence of parasites in the gastrointestinal tract, lungs and liver can be detected by parasitological examinations of appropriate samples, usually faeces, for the presence of their eggs, cysts or larval stages. This review focuses on the clinical and laboratory diagnostic approaches to a number of important parasitic diseases of sheep, in particular, parasitic gastroenteritis and the detection of species showing the presence of anthelmintic resistance, as well as other diseases, such as liver fluke and coccidiosis. The diagnosis of ectoparasite infections is generally much more straightforward, because of their size and location on the skin. However, misidentification can occur without appropriate experience in parasite identification. Accurate and correct diagnosis is fundamental to good parasite control, otherwise inappropriate or consequential, apparent treatment failures may occur. © 2010.
Crews C.,UK Environment Agency
Journal of Apicultural Research | Year: 2014
Semicarbazide (SEM) is a product of the metabolism or degradation of the antimicrobial veterinary drug nitrofurazone. The drug is prohibited for use in food-producing animals in the UK, and detection of SEM is used as an indication of nitrofurazone abuse. SEM was reported in several heather honey samples tested in Scotland and Northern England in 2009, and also in two samples of wild forest honey from New Zealand in 2011. The hives from which these samples were taken were strongly considered to have been free from nitrofurazone treatment, and therefore a natural source of SEM was suspected. The natural formation of SEM has been demonstrated in certain shellfish, seaweed, eggs, and whey, with arginine and creatinine proposed as its precursors. This paper reviews the natural formation of SEM in foods to help to identify a natural source in honey. A possible source is a sudden increase in arginine levels in heather pollen shortly before and during the production of the affected honey. Other possible sources of the SEM are unidentified precursors and environmental contaminants, including urine from sheep or wild animals. © IBRA 2014.
Richards E.H.,UK Environment Agency
Parasitology | Year: 2011
The ectoparasitic honey bee mite Varroa destructor feeds on the haemolymph of the honey bee, Apis mellifera, through a single puncture wound that does not heal but remains open for several days. It was hypothesized that factors in the varroa saliva are responsible for this aberrant wound healing. An in vitro procedure was developed for collecting salivary gland secretions from V. destructor. Mites were incubated on balls of cotton wool soaked in a tissue culture medium (TC-100), and then induced to spit by topical application of an ethanolic pilocarpine solution. Elution of secretions from balls of cotton wool, followed by electrophoretic analysis by SDS-PAGE and electroblotting indicated the presence of at least 15 distinct protein bands, with molecular weights ranging from 130 kDa to <17 kDa. Serial titration of V. destructor salivary secretions in TC-100 followed by an 18-h incubation with haemocytes from the caterpillar, Lacanobia oleracea, indicated that the secretions damage the haemocytes and suppresses their ability to extend pseudopods and form aggregates. We suggest that these secretions facilitate the ability of V. destructor to feed repeatedly off their bee hosts by suppressing haemocyte-mediated wound healing and plugging responses in the host.
Ruse L.,UK Environment Agency
Ecological Indicators | Year: 2010
The European Union Water Framework Directive (WFD) aims to achieve Good ecological status of its waterbodies by 2015 through the determination of reference state to provide a measure of perturbation by human impacts based on taxonomic composition and abundance of aquatic species. Collections of floating pupal exuviae discarded by emerging adult midges (Diptera: Chironomidae) provide a cost-effective method for obtaining representative ecological data from lakes. Chironomid and environmental data were collected from 178 lake surveys (4 samples from each lake) of all WFD types found in Britain. Canonical Correspondence Analysis (CCA) provided species optima and niche breadths in relation to mean nutrient (nitrogen and phosphorus) concentrations. A nutrient impact score derived from species optima was produced for each lake survey and compared with the lake's reference score based on its physical characteristics. A range of reference lake types provided a model of physical characteristics for their observed chironomid species-derived nutrient scores. The Ecological Quality Ratio (EQR) of observed to reference scores were classified into WFD quality bands based on the relative frequency of sensitive to tolerant chironomid species. Sampling errors based on EQR variation were used to determine the confidence of each lake survey classification. Species-based EQR provided a sensitive measure of a lake's perturbation from high ecological status. Analyses were repeated with genus-level data obtained in much less time and with less taxonomic expertise. Precision obtaining EQR from generic data was lower but still acceptable for providing a high confidence of lake ecological classification. © 2009 Elsevier Ltd. All rights reserved.