Genomic variability among globally distributed isolates of equine arteritis virus.     

T W Murphy  W H McCollum  P J Timoney  B W Klingeborn  B Hyllseth  W Golnik  B Erasmus 《Veterinary microbiology》1992,32(2):101-115

Equine arteritis virus (EAV), a non-arthropod borne togavirus, has been shown to have a global distribution. To date, no major antigenic variation has been demonstrated between EAV isolates from different geographic origins. In this study, the genomic RNA of EAV isolates obtained from horses of different breeds in various countries around the world was oligonucleotide fingerprinted. Comparisons of these fingerprints were used to determine the extent of genomic variation among such isolates. Comparisons among isolates from North American horses revealed, for the most part, oligonucleotide homologies of less than 60%. Only 29 of the 98 comparisons revealed greater than 60% oligonucleotide homology. Nonetheless, several comparisons indicated a close epidemiologic relationship between isolates from horses of different breeds located in different states. Though all European isolates were of Standardbred origin and were from horses located in northern European countries, the majority had oligonucleotide homologies of less than 60%. Where oligonucleotide homology was apparent, it was, with one exception, greater than 70%. The two isolates from New Zealand had 93.2% oligonucleotide homology. This is indicative of an extremely close epidemiologic relationship. Comparisons between EAV isolates from around the world revealed oligonucleotide homologies between viruses from North America, Europe and New Zealand. In several instances, this homology was greater than 70% and in one case greater than 80%. No oligonucleotide homology was evident in comparisons involving the virus from South Africa. The high level of genomic conservation between certain EAV isolates of disparate geographic origins may reflect dissemination of the virus associated with the international movement of horses. The extent of genomic variation demonstrated between most of the EAV isolates used in this study confirms the need for further investigation of genomic heterogeneity among strains of this virus before techniques that rely upon nucleic acid hybridization can be effectively applied as diagnostic procedures.  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   

Electrotrawling: a promising alternative fishing technique warranting further exploration          下载免费PDF全文

Maarten Soetaert  Annemie Decostere  Hans Polet  Bart Verschueren  Koen Chiers 《Fish and Fisheries》2015,16(1):104-124

In trawl fisheries, beam trawls with tickler chains, chain mats or bobbin ropes are used to target flatfish or shrimp. High fuel consumption, seabed disturbance and high discard rates are well‐known disadvantages of this fishing technique. These shortcomings are increasingly gaining international public and political attention, especially with the upcoming discard ban in Europe. The most promising alternative fishing technique meeting both the fisherman's aspirations, and the need for ecological progress is pulse fishing with electrotrawls. Here, the mechanical stimulation by tickler chains or bobbins is replaced by electrical stimulation resulting in reduced bottom contact, fuel costs and discards. Although a significant amount of research has been done on electrotrawls and their impact on marine organisms, most data were published in very diverse sources ranging from local non‐peer‐reviewed reports with a limited distribution to highly consulted international peer‐reviewed journals. Therefore, there is a clear need for a comprehensive yet concise and critical overview, covering and summarizing all these data and making these available for the scientific community. This article aims to meet the above goals by discussing the working principle of electric fields, the history of electrotrawls and their current application in the North Sea and impact on marine organisms. It is concluded by elaborating on the opportunities and challenges for the further implementation of this alternative fishing technique.  相似文献   

Effect of Megasphaera elsdenii NCIMB 41125 dosing on rumen development,volatile fatty acid production and blood β‐hydroxybutyrate in neonatal dairy calves          下载免费PDF全文

M. C. Muya  F. V. Nherera  K. A. Miller  C. C. Aperce  P. M. Moshidi  L. J. Erasmus 《Journal of animal physiology and animal nutrition》2015,99(5):913-918

Thirty calves were randomly assigned to two treatments and fed until weaning [42 days (d) of age]. Treatments were a control group (n = 15), which did not receive Megasphaera elsdenii (Me0) and a M. elsdenii group, which received a 50‐ml oral dose of M. elsdenii NCIMB 41125 (10⁸ CFU/ml) at day 14 day of age (Me14). Calves were given colostrum for the first 3 day followed by limited whole milk feeding. A commercial calf starter was offered ad libitum starting at day 4 until the end of the study. Fresh water was available throughout the study. Feed intake and growth were measured. Blood samples were collected via jugular venipuncture to determine β‐hydroxybutyrate (BHBA) concentrations. Fourteen male calves (seven per group) were euthanised on day 42 and digestive tracts harvested. Reticulo‐rumen weight was determined and rumen tissue samples collected from the cranial and caudal sacs of the ventral and dorsal portions of the rumen for measurements of papillae length, papillae width and rumen wall thickness. Dosing with M. elsdenii NCIMB 41125 improved starter dry matter intake (DMI), weaning body weight (BW) and tended to improve average daily gain. Calves in Me14 group had greater plasma BHBA concentration than Me0‐calves during the last 3 weeks of the trial and had at day 42 greater reticulo‐rumen weight, papillae width and papillae density compared to Me0. No differences in rumen wall thickness or papillae length were observed between the two groups. Total volatile fatty acids, acetate and propionate production did not differ between treatments, but butyrate production was greater in Me14 than Me0. Dosing M. elsdenii NCIMB 41125 showed benefit for calves with improved feed intake and rumen development suggesting increased epithelium metabolism and improved absorption of digestive end products.  相似文献   

Genotoxicity of melanoidin fractions derived from a standard glucose/glycine model   总被引：2，自引：0，他引：2  

Taylor JL  Demyttenaere JC  Abbaspour Tehrani K  Olave CA  Regniers L  Verschaeve L  Maes A  Elgorashi EE  van Staden J  de Kimpe N 《Journal of agricultural and food chemistry》2004,52(2):318-323

Genotoxic compounds can act at various levels in the cell (causing gene, chromosome, or genome mutations), necessitating the use of a range of genotoxicity assays designed to detect these different types of mutations. The production of melanoidins during the processing and cooking of foods is associated with changes in their nutritional character, and the discovery of mutagenic substances in pyrolyzed protein and amino acids has raised concern about the safety of these foods. The aim of this work was to test melanoidin fractions in three different in vitro assays (Ames test, Vitotox test, and micronucleus test). These melanoidin fractions were produced from the condensation of glucose with glycine and their separation was conducted by dialysis. The crude reaction mixture (before dialysis) and both the LMW and HMW fractions obtained by dialysis showed no genotoxicity in these assays, despite being tested at concentrations much higher than those naturally found in food products. The LMW fraction, however, showed toxicity at these high concentrations. The volatile fraction produced in this reaction showed genotoxicity only in the Vitotox test, at high concentrations.  相似文献   

Effects of an arbuscular mycorrhizal fungus and two plant-parasitic nematodes on<Emphasis Type="Italic"> Musa</Emphasis> genotypes differing in root morphology     

Annemie?ElsenEmail author  Raf?Beeterens  Rony?Swennen  Dirk?De?Waele 《Biology and Fertility of Soils》2003,38(6):367-376

In this study, the effect of an arbuscular mycorrhizal fungus (AMF) and two migratory endoparasitic nematodes on Musa plant growth, including the root system, were examined. In addition, the AMF-nematode interaction was studied. Seven Musa genotypes with different root systems were selected. Based on their relative mycorrhizal dependency, two genotypes (Calcutta 4 and Obino l'Ewai) were selected for AMF-nematode interaction studies. The experiments were performed under greenhouse conditions. Mycorrhization with Glomus mosseae resulted in a significantly better plant growth even in the presence of nematodes. The effect of AMF on the root system was genotype-dependent and seemed to be related to the relative mycorrhizal dependency of the genotype. The nematodes also affected the root system, decreasing branching. Nematode population densities were significantly reduced in the presence of AMF, except for Pratylenchus coffeae in Obino l'Ewai. In the root system, it appeared that the decreased branching caused by the nematodes was counterbalanced by the increased branching caused by the AMF.  相似文献   

Some features of coagulase positive staphylococci from bovine milk. II. Comparison of conventional techniques and the API Staph system   总被引：1，自引：0，他引：1  

J A Erasmus  P A Brand  M M Galbraith 《The Onderstepoort journal of veterinary research》1987,54(2):159-160

A total of 150 isolates of Staphylococcus aureus were subjected to the tests on the API Staph system. Of these, 50 were also tested by conventional methods, using the same tests as those found on the API Staph strips. Applying the principles of numerical taxonomy, the relationship between these isolates was 82% and more. Tests for the metabolism of sucrose and N-acetyl-glucosamine and for the production of argenine dihydrolysate and urease appear to be superfluous in the identification of S. aureus in this system.  相似文献   

Studies on the transmission of African horsesickness     

H Wetzel  E M Nevill  B J Erasmus 《The Onderstepoort journal of veterinary research》1970,37(3):165-168

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Recent changes in Salmonella nomenclature: the need for clarification     

Heyndrickx M  Pasmans F  Ducatelle R  Decostere A  Haesebrouck F 《Veterinary journal (London, England : 1997)》2005,170(3):275-277

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Indigenous peoples' food systems for health: finding interventions that work     

Kuhnlein H  Erasmus B  Creed-Kanashiro H  Englberger L  Okeke C  Turner N  Allen L  Bhattacharjee L 《Public health nutrition》2006,9(8):1013-1019

This is a short report of a 'safari' held in conjunction with the International Congress of Nutrition in September 2005, in Futululu, St. Lucia, South Africa. Participants were several members of the International Union of Nutritional Sciences Task Force on Indigenous Peoples' Food Systems and Nutrition, other interested scientists and members of the Kwa Zulu indigenous community. The paper describes the rationale for and contributions towards understanding what might be successful interventions that would resonate among indigenous communities in many areas of the world. A summary of possible evaluation strategies of such interventions is also given.  相似文献