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21.
Borgsteede F Verkaik J Moll L Dercksen D Vellema P Bavinck G 《Tijdschrift voor diergeneeskunde》2010,135(21):782-785
In Autumn 2009, a faecal egg count reduction test (FERCT) was carried out on three sheep farms. Groups of 8-11 lambs were treated with ivermectin or moxidectin, with a 14-day interval between treatment and sampling. Ivermectin resistance was present on all three farms. Treatment with ivermectin resulted in a reduction in faecal egg numbers of 94.6%, 63%, and 59%. On two farms, 14 days after treatment pooled faecal samples yielded predominantly larvae of Hamonchus contortus (100% and 98%, respectively). On the third farm, H. contortus and (probably) Teladorsagia circumcincta were resistant to ivermectin (64% and 36% of the larvae, respectively). Treatment with moxidectin resulted in a 100% reduction in egg output in sheep on all three farms. More sensitive culture techniques failed to detect any larvae in samples taken from two farms, but a few Ostertagia-type larvae, probably of T. circumcincta, were detected in samples from the third farm. It can be concluded that gastrointestinal nematodes in sheep from these three farms were resistant to ivermectin, whereas resistance to moxidectin was not detected. 相似文献
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Pieterjan Verhelst Jan Reubens Ine Pauwels David Buysse Bart Aelterman Stijn Van Hoey Peter Goethals Tom Moens Johan Coeck Ans Mouton 《Ecology of Freshwater Fish》2018,27(1):471-480
Due to a recruitment decline of more than 90% in 30 years, the European eel (Anguilla anguilla L.) has been classified by IUCN as critically endangered. Although the species has been studied intensively to obtain knowledge to improve management, studies about the resident yellow stage are relatively scarce. In this study, 52 large female yellow eels were tagged with acoustic transmitters in a Belgian polder system and tracked by a network of 23 automatic listening stations. We studied both circadian and seasonal movement patterns and the effect of environmental variables on these patterns. Large female yellow eels were most active at night in late summer and early autumn. A generalised linear mixed model showed that their movement is only slightly influenced by environmental variables. Moreover, as yellow eels show high site fidelity (i.e., the majority was detected only in the habitat type of their catch‐release location), they do not encounter many human‐induced connectivity problems in polder systems, which makes these systems highly suitable as eel growth habitat. These results can contribute to an effective eel management regarding habitat protection and restoration. 相似文献
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Jeroen Peters Wojciech Sledz Jan H. W. Bergervoet Jan M. van der Wolf 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(2):97-107
An enrichment microsphere immunoassay (MIA) was developed, based on the Luminex xMAP® technology, for the simultaneous (duplex) detection of Pectobacterium atrosepticum (former name Erwinia carotovora subsp. atroseptica) (Pca) and Dickeya dianthicola (former name Erwinia chrysanthemi) (Dcd) in potato plant extracts. Target bacteria in the extracts were enriched for 48 h in a semi-selective broth containing polypectate under low oxygen conditions. Samples were subsequently incubated with antibody-coated colour-coded microspheres (beads) and with secondary antibodies conjugated with Alexa Fluor® 532, a reporter dye. Samples were analyzed with the Luminex analyzer, in which one laser identified each microsphere and another laser the reporter dye conjugated to the secondary antibodies. The assay required minimal sample preparation, could be completed in 1 h, was performed in 96 wells microtitreplates and required no wash steps. The limit of detection for the duplex enrichment MIA was 100–1000 cfu ml?1, which was a hundred times lower than of an enrichment-ELISA. Without enrichment, the sensitivity of MIA and ELISA was largely similar and ranged between 106 and 107 cells ml?1. No difference in sensitivity was found between a MIA in a single or duplex format. In a comparative test with non-infected potato plant extracts and extracts from plants infected with Pca or Dcd, results of the enrichment MIA correlated well with those of the enrichment ELISA and enrichment PCR. These results indicate that MIA can be reliably used for multiplex detection of soft rot Enterbacteriaceae in crude potato plant extracts. The technology is an attractive and cost-effective alternative to other detection methods, including ELISA. 相似文献
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ABSTRACT Plant-associated microorganisms are critical to agricultural and food security and are key components in maintaining the balance of our ecosystems. Some of these diverse microbes, which include viruses, bacteria, oomycetes, fungi, and nematodes, cause plant diseases, whereas others prevent diseases or enhance plant growth. Despite their importance, we know little about them on a genomic level. To intervene in disease and understand the basis of biological control or symbiotic relationships, a concerted and coordinated genomic analysis of these microbes is essential. Genome analysis, in this context, refers to the structural and functional analysis of the microbe DNA including the genes, the proteins encoded by those genes, as well as noncoding sequences involved in genome dynamics and function. The ultimate emphasis is on understanding genomic functions involved in plant associations. Members of The American Phytopathological Society (APS) developed a prioritized list of plant-associated microbes for genome analysis. With this list as a foundation for discussions, a Workshop on Genomic Analysis of Plant-Associated Microorganisms was held in Washington, D.C., on 9 to 11 April 2002. The workshop was organized by the Public Policy Board of APS, and was funded by the Department of Energy (DOE), the National Science Foundation (NSF), U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS), and USDA-National Research Initiatives (USDA-NRI). The workshop included academic, industrial, and governmental experts from the genomics and microbial research communities and observers from the federal funding agencies. After reviewing current and near-term technologies, workshop participants proposed a comprehensive, international initiative to obtain the genomic information needed to understand these important microbes and their interactions with host plants and the environment. Specifically, the recommendations call for a 5-year, $500 million international public effort for genome analysis of plant-associated microbes. The goals are to (i) obtain genome sequence information for several representative groups of microbes; (ii) identify and determine function for the genes/proteins and other genomic elements involved in plant-microbe interactions; (iii) develop and implement standardized bioinformatic tools and a database system that is applicable across all microbes; and (iv) educate and train scientists with skills and knowledge of biological and computational sciences who will apply the information to the protection of our food sources and environment. 相似文献
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Jan Fahleson Ulf Lagercrantz Qiong Hu Lisa Ann Steventon Christina Dixelius 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(4):361-371
Amplified fragment length polymorphism (AFLP) analysis was used to study genetic variation among 76 isolates of Verticillium. A dendrogram based on the AFLP data revealed three main groups. One group consisted of 35 European isolates derived from Brassica napus together with five Californian isolates taken from B. oleracea. This group displayed a high degree of genetic similarity and included three isolates earlier classified as Verticillium longisporum, indicating that all isolates in this group probably should be regarded as members of V. longisporum. V. dahliae isolates constituted the second group while the third group contained four V. albo-atrum isolates. In addition to these three groups, a cluster of six V. nigrescens isolates was observed. However, the genetic distances between the isolates of V. nigrescens were much higher than those between members in the other groups and the bootstrap value for the V. nigrescens cluster was subsequently low. Four isolates classified as V. tricorpus were highly diverse and did not cluster together. Analysis of molecular variance revealed that the isolates of V. longisporum were separated into four subgroups, based on geographic origin. The study furthermore shows that AFLP is a suitable method for studying population structure in Verticillium. 相似文献
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Janusz Popawski Boena ozowicka Alina T Dubis Barbara Lachowska Zbigiew Winiecki Jan Nawrot 《Pest management science》2000,56(6):560-564
All isomers of α‐asarone [(E)‐4‐prop‐1‐enyl‐1,2,5‐trimethoxybenzene] were tested for their feeding deterrent activity against adults of Sitophilus granarius and Tribolium confusum and larvae of Trogoderma granarium and Tribolium confusum. (E)‐2‐prop‐1‐enyl‐1,3,5‐trimethoxybenzene exhibited the strongest deterrent activity against all the species tested. The total coefficients of deterrency for this compound were 140.6 and 169.7 for Tribolium confusum adults and larvae, respectively, and 144.9 and 104.6 for larvae of Trogoderma granarium and adults of Sitophilus granarius, respectively. © 2000 Society of Chemical Industry 相似文献