Reliable ELISAs showing differences between resistant and susceptible lines in hens orally inoculated with Salmonella Enteritidis     

Proux K  Jouy E  Houdayer C  Protais J  Dibb-Füller M  Boscher E  Gillard A  Gracieux P  Gilbert F  Beaumont C  Duchet-Suchaux M 《Veterinary research》2002,33(1):23-33

Reliable ELISAs were investigated with the aim to select hen lines resistant to Salmonella Enteritidis and producing high levels of antibodies. In the first experiment, the relation between the humoral response and the bacteriological results was assessed on hens from the Y11 resistant line and the L2 susceptible line, orally inoculated with 10(8) CFU S. Enteritidis per animal. Anti-lipopolysaccharide (LPS) IgG titres were higher but the liver and spleen were less contaminated in hens from the Y11 line than in hens from the L2 line (p = 0.013, 0.031 and 0.026 respectively). In the second experiment, the hens were inoculated orally with 1.7 x 10(8) CFU S. Enteritidis per animal in order to select the ELISA methods showing the more significant differences. ELISAs were based on LPS, flagella, LPS from rough (LPS-R) and smooth strains (LPS-S) and detected IgG and IgM antibodies from sera and yolks. No between-line host response variation was observed in the yolk, with LPS-S and R antigens nor with anti-LPS IgM in the sera. Otherwise, significant differences were encountered between hen lines with the ELISAs performed on the sera detecting anti-LPS IgG, anti-flagella IgG or IgM (p = 0.017, 0.017 and p < 0.001 respectively). When comparing the kinetics of the selected ELISAs, the IgG antibodies against LPS detected between-line variations as early as 1 to 4 weeks pi, whereas with IgG against flagella, the differences were only detected at 1 and 2 weeks pi and with IgM against flagella, the differences were significant at 1, 2, 4 and 8 weeks pi. In conclusion, resistant hen lines producing higher levels of antibodies than the susceptible hen lines may be selected with these ELISAs.  相似文献   

Severity and persistence of footrot in Merino sheep experimentally infected with a protease thermostable strain of Dichelobacter nodosus at five sites     

LJ DEPIAZZI  WD ROBERTS  CD HAWKINS  MA PALMER  DR PITMAN  NC MCQUADE  PD JELINEK  DJ DEVEREAUX  RJ RIPPON 《Australian veterinary journal》1998,76(1):32-38

Objective To test the hypothesis that ovine footrot associated with a thermostable protease strain of Dichelobacter nodosus undergoes self cure or is sustained as an annually recurring disease, depending on the environment.
Design and procedure Forty Merino sheep from a single blood line were infected with a protease thermostable strain of D nodosus a t each of five sites in Western Australia. Footrot lesions and microscopic evidence of D nodosus were recorded every fortnight for 2.5 years, supplemented by laboratory culture. Rainfall, soil and air temperature, pasture quantity and composition and soil types were also recorded. Flocks that apparently self cured were relocated to a more favourable site for footrot in the final spring season.
Results The maximum prevalence of feet with clinical footrot lesions was 80.6, 1.3, 14.4, 3.8 and 88.1% at the five sites. Severe footrot occurred for three consecutive spring seasons at one site that had clay loam soil and at least 3500 kg/ha total pasture dry matter annually. However, the infection was asymptomatic for up to 10 weeks between outbreaks. D nodosus was isolated from flocks for 2.5 years at only two sites, although there was microscopic evidence of the organism at other sites in the final year. A thermolabile variant (strain U6) of D nodosus was isolated from the two sites where footrot persisted.
Conclusion Depending on time and location, ovine footrot induced by a protease thermostable strain of D nodosus either self cured or persisted as annual outbreaks interspersed with periods of asymptomatic infection.  相似文献   

Confirmation and quantification of pesticide residues by mass spectrometry     

John Gilbert  James R. Startin  Colin Crews 《Pest management science》1987,18(4):273-290

The sensitivity and specificity of mass spectrometry makes this an attractive technique for the confirmation and quantification of trace levels of pesticide residues. Two applications of mass spectrometry are outlined, that of combined headspace gas chromatography (g.c.)/mass spectrometry (m.s.), for the analysis of volatile fumigants such as ethylene dibromide (EDB) in imported fruits and multi-residue halogenated compounds in bran products, and that of quantitative g.c./m.s. for the determination of a range of organochlorine pesticide residues. The approach to setting-up a capillary g.c. multiple ion monitoring programme is described, with emphasis on quantitative aspects, and in particular the use of stable isotope internal standards. This is illustrated with an example of the quantification of organochlorine pesticide residues in eggs.  相似文献   

Phosphonate—hydrogen exchange in aqueous solutions of 2H and 3H-labelled phosphonic acid     

Gilbert Bompeix  Ramon Burgada  Agns D'arcy Lameta  Marie-Christine Souli 《Pest management science》1989,25(2):171-174

Phosphonic acid (phosphorous acid), H — PO(OH)₂, the active breakdown product in plant tissues of the systemic anti-oomycete fungicide fosetyl-aluminium was investigated in order to assay the stability of the labelled compound. There is a strong and fast isotopic exchange in unbuffered aqueous solutions of ²H — PO(OH)₂, and therefore ³H — PO(OH)₂, so that Fenn and Coffey's experiments must be reinterpreted because these authors used a stock solution of pure labelled phosphonic acid. However, it is possible to use this last compound for biological experiments under the following conditions: (1) Keeping the dry sodium salt ³H — PO(ONa)₂. 5H₂O in small flasks (100 mg, 37 MBq each) in a vacuum desiccator for individual use without fractionation; (2) using the compound at neutral or slightly acidic pH.  相似文献   

First report of Exserohilum pedicellatum on Zea mays in Australia     

R. L. Gilbert 《Plant pathology》2003,52(3):404-404

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Nonresponsive generalized bacterial infection associated with systemic lupus erythematosus in a Beauceron.     

C Clercx  K McEntee  S Gilbert  L Michiels  F Snaps  E Jacquinet  D Desmecht  M Henroteaux  W E Bernadina 《Journal of the American Animal Hospital Association》1999,35(3):220, 222, 224-220, 222, 228

A case of concurrent canine systemic lupus erythematosus (SLE) and generalized bacterial infection in a six-year-old female Beauceron is reported. The dog presented with purulent nasal and ocular discharges, skin lesions (including seborrhea, hyperkeratotic areas, and papules as well as ecchymoses around the eyes, on both sides of the pinnae, and on the vulva), generalized lymph node enlargement, a mitral murmur, and lameness. Later, facial swelling, a retrobulbar abscess, and a cough also developed. Occurrence of a generalized bacterial infection was established by culture of group-C, beta-hemolytic Streptococcus from the throat, the mouth, a biopsy site (popliteal lymph node area), the retrobulbar abscess, and the lung. The diagnosis of SLE was based on the clinical signs and particularly on the occurrence of antinuclear antibody (ANA) and antidoublestranded-desoxyribonucleic acid (ds-DNA) antibody. Interestingly, the latter type of antibodies were also detected in two young female puppies whelped by this dog. Salient histological findings included an extreme cell depletion of the lymph nodes and spleen and severe pneumonitis and peribronchiolitis. The results of this case indicate that a definite diagnosis of canine SLE can, at times, be made on the basis of the presence of serum ANA and ds-DNA antibodies.  相似文献   

Regulatory Risk Assessment of Pesticide Residues in Air     

Gilbert  A. J. 《Water, air, and soil pollution》1999,115(1-4):183-194

Background information describing current approaches taken by different countries to risk assessment in regard of pesticide residues in air is presented with a view to stimulating discussion of the subject in order to identify means for improving both the underlying science and administrative procedures concerned. Fundamental regulatory objectives are explored, alternative guidelines for conduct of exposure evaluation, risk assessment and regulatory decision making are examined and the basic components of the technical framework in which this complex work is carried out are discussed. The criteria which are capable of being used for regulatory decision support are considered with a view to questioning their feasibility for practical use and relevance for operation to provide a robust basis for regulatory risk assessment for plant protection products. Brief recommendations are given for aspects of discussion where attention should be focused.  相似文献   

Efficacy of fluorescent calcein mark retention and identification in endangered Colorado pikeminnow Ptychocheilus lucius     

Eliza I. Gilbert  Scott L. Durst  Tracy A. Diver  Hannah Mello  Nick G. Bertrand  Nathan R. Franssen 《Fisheries Management and Ecology》2020,27(3):258-269

Distinguishing hatchery‐reared fishes from wild conspecifics can be required to quantify the success of augmentation programmes. This study estimated the probability of identifying calcein‐marked, hatchery‐reared Colorado pikeminnow Ptychocheilus lucius Girard from external and internal structures. Both control and marked fish held in the laboratory were correctly identified 80% of the time after 300 days. A fluorometer was more accurate 180 days post‐marking, whereas visual observation was more discriminating at 300 days. There were no differences in detection rates among structures in laboratory fish, and for most structures of fish held outdoors, detection rates were <20%. Overall, a strong negative effect of light on mark persistence was observed. Also, an initial positive effect of fish size on mark fluorescence and a negative effect of fish growth were detected. These results suggest the potential use of calcein as a batch‐marking tool would be aided by future studies that better quantify light exposure and calcein mark persistence in both field and experimental settings.  相似文献   

Heritabilities and genetic correlations for postweaning growth and feed intake of beef bulls and steers     

M D MacNeil  D R Bailey  J J Urick  R P Gilbert  W L Reynolds 《Journal of animal science》1991,69(8):3183-3189

Data from studies conducted at Miles City, MT and Lethbridge, AB were pooled to evaluate genetic and environmental variation in feed intake (MEI), growth rate (ADG), MEI-to-gain ratio (M/G), final weight (FWT), and fat thickness (FAT). A total of 124 sires with an average of 4.25 progeny each were represented in the data. Restricted maximum likelihood methods were used to estimate within and between paternal half-sib estimates of variance and covariance. Heritabilities and genetic, phenotypic, and environmental correlations with inference to populations at 365 d of age were calculated from the estimates. Heritabilities were as follows: ADG, .38 +/- .16; MEI, .45 +/- .17; M/G, .26 +/- .15; FWT .25 +/- .15; and FAT .52 +/- .17. The genetic correlation of MEI with ADG was large (.73 +/- .13) and antagonistic to genetic improvement of M/G through selection for ADG. Efficient genetic improvement in M/G was found to depend on using either MEI or an indicator of composition of gain as selection criteria in addition to ADG. Selection to improve M/G using an index that included FWT and FAT, in addition to MEI and ADG, resulted in greater predicted response in ADG and lesser predicted response in MEI than the index of ADG and MEI alone.  相似文献   

Survival of viruses in fermented edible waste material   总被引：1，自引：0，他引：1  

R E Wooley  J P Gilbert  W K Whitehead  E B Shotts  C N Dobbins 《American journal of veterinary research》1981,42(1):87-90

The survival of selected viruses in fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Seven viruses, including pseudorabies, Newcastle disease, infectious canine hepatitis, avian infectious bronchitis, measles, vesicular stomatitis, and a porcine picornavirus were inoculated into a mixture of ground food waste (collected from a school lung program) containing Lactobacillus acidophilus. Mixtures were incubated at 5 C, 10 C, 20 C, and 30 C for 96 hours. Temperature, pH, and redox potential were monitored. Samples for virus isolation were obtained daily. Newcastle disease virus and infectious canine hepatitis virus survived the entire test period. The porcine picornavirus was inactivated at 30 C after 74 hours, but survived for the entire test period at the other temperatures. Pseudorabies virus was inactivated at 20 C and 30 C within 24 hours, but survived for 48 hours at 10 C and 96 hours at 5 C. Avian infectious bronchitis virus was inactivated at 20 C and 30 C within 24 hours, but survived 72 hours at 5 C and 10 C. Measles and vesicular stomatitis viruses were rapidly inactivated at all 4 temperatures.  相似文献