Characterization of multidrug resistant Salmonella recovered from diseased animals     

Zhao S  McDermott PF  White DG  Qaiyumi S  Friedman SL  Abbott JW  Glenn A  Ayers SL  Post KW  Fales WH  Wilson RB  Reggiardo C  Walker RD 《Veterinary microbiology》2007,123(1-3):122-132

Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one antimicrobial, and 265 (70%) to three or more antimicrobials. Resistance was most often observed to tetracycline (78%), followed by streptomycin (73%), sulfamethoxazole (68%), and ampicillin (54%), and to a lesser extent chloramphenicol (37%), kanamycin (37%), amoxicillin-clavulanic acid (20%), and ceftiofur (17%). With regards to animal of origin, swine Salmonella isolates displayed the highest rate of resistance, being resistant to at least one antimicrobial (92%), followed by those recovered from turkey (91%), cattle (77%), chicken (68%), and equine (20%). Serovars commonly showing multidrug resistance (MDR) to > or =9 antimicrobials were S. Uganda (100%), S. Agona (79%), and S. Newport (62%), compared to S. Heidelberg (11%) and S. Typhimurium (7%). Class-1 integrons were detected in 43% of all isolates, and were found to contain aadA, aadB, dhfr, cmlA and sat1 gene cassettes alone or in various combinations. All ceftiofur resistant isolates (n=66) carried the bla(CMY) beta-lactamase gene. A total of 230 PFGE patterns were generated among the 380 isolates tested using XbaI, indicating extensive genetic diversity across recovered Salmonella serovars, however, several MDR clones were repeatedly recovered from different diseased animals.  相似文献   

Localization of insulin-like growth factor (IGFBP)-3 in cultured porcine embryonic myogenic cells before and after TGF-beta1 treatment     

Xi G  Hathaway MR  White ME  Dayton WR 《Domestic animal endocrinology》2007,33(4):422-429

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Improving response rates: introducing an anonymous longitudinal survey research protocol for veterinary medical students     

Reisbig AM  Hafen M  White MB  Rush BR 《Journal of veterinary medical education》2007,34(2):194-201

With the Journal of Veterinary Medical Education's recent summer 2005 theme issue on stress, the mental-health concerns of veterinary medical students has been brought to the forefront of the field. Since it is anticipated that research on this topic will continue and that educational institutions may implement changes based upon these results, it is of the utmost importance that this research be of the highest quality. Of particular concern with human-subject inquiries are response rates and confidentiality. In order to accommodate these concerns, an example of a survey research protocol that promotes high response rates and minimizes threats to internal validity influenced by student mistrust in assurances of confidentiality is presented. Specifically, the protocol is designed to ensure anonymity and to preserve the ability to track students longitudinally through the use of anonymous longitudinal identifiers. This protocol was tested with the first-year class of veterinary medical students at Kansas State University in October 2004 and March 2005. The two data collection periods yielded 90% and 76% response rates, respectively. The matching rate of participants, according to the anonymous longitudinal identifiers from Time 1 to Time 2, was 88%.  相似文献   

Assessing the association of single nucleotide polymorphisms at the thyroglobulin gene with carcass traits in beef cattle     

Casas E  White SN  Shackelford SD  Wheeler TL  Koohmaraie M  Bennett GL  Smith TP 《Journal of animal science》2007,85(11):2807-2814

The objective of this study was to assess the association of SNP in the thyroglobulin gene, including a previously reported marker in current industry use, with marbling score in beef cattle. Three populations, designated GPE6, GPE7, and GPE8, were studied. The GPE6 population sampled breeds that could be used as alternative germplasm sources in beef cattle production, including Wagyu, Swedish Red and White, Friesian, and Norwegian Red. The GPE7 population sampled 7 popular beef cattle breeds used in temperate climates of the United States: Angus, Charolais, Gelbvieh, Hereford, Limousin, Red Angus, and Simmental. The GPE8 population sampled Bos indicus-influenced breeds used in subtropical regions of the country and subtropical and tropical regions of the world, including Beefmaster, Bonsmara, Brangus, and Romosinuano. Evaluation of 6 SNP in the thyroglobulin gene, including 5 newly described variations, showed no association (P > 0.10) with marbling score in these populations, except a tendency (P < 0.10) for an association with the previously described marker in GPE6. Closer examination of the GPE6 data revealed that the source of the tendency was an association (P < 0.02) with marbling in animals of Wagyu inheritance. Animals having Wagyu background and inheriting the TT genotype had a greater marbling score (599 +/- 20) than those inheriting the CC (540 +/- 10) or the CT (541 +/- 11) genotype. No association was detected with any other carcass trait for this marker in the 3 populations. Furthermore, none of the 5 newly described markers in the gene displayed an association with marbling score. The data indicate that markers at the thyroglobulin gene may be a useful predictor of marbling performance for producers raising Wagyu-based cattle. Although associations with marbling score in the remaining populations were not large or significant, the TT genotype had the numerically greatest marbling score in each population.  相似文献   

Evaluation of serum 25-hydroxyvitamin D,C-reactive protein,and haptoglobin as biomarkers in dogs newly diagnosed with histoplasmosis     

Betsy Hernandez  Jared A. Jaffey  Leah A. Cohn  Robert C. Backus  Kate KuKanich  Andrew S. Hanzlicek  Valerie J. Parker  Mary E. White  Randy Ringold  Emily Westerback  Leah Freilich  Charlotte Bolch 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2023,37(2):476-483

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The growth and nitrogen economy of rice under sprinkler and flood irrigation in South East Australia     

E. Humphreys  F. M. Melhuish  W. A. Muirhead  R. J. G. White  J. Blackwell  P. M. Chalk 《Irrigation Science》1989,10(4):281-292

Summary ¹⁵N balances were compared in rice (Oryza sativa L., cv. Calrose) grown under continuous flood (CF) or sprinkler irrigation. Two sprinkler treatments with irrigation frequencies of once (S1W) and thrice (S3W) per week were studied. Five atom %¹⁵N-labelled urea (60 kg N ha^–1) was applied to microplots either 36 or 84 days after emergence (DAE). An equivalent amount of unlabelled urea was applied at the other application time, so that each microplot received a total of 120 kg N ha^–1 in an equal split. There was no significant effect of irrigation treatment on recovery of urea N by straw. Straw recovery from urea applied 36 DAE was almost half that from an application 84 DAE, and time of urea application produced a similar effect on recovery in grain. Grain recovery in S1W was less than half that in CF and S3W for both application times. Total plant recovery of urea N applied 36 DAE was similar for all irrigation treatments (average 29%), but for urea applied 84 DAE total plant recovery in CF (67%) was significantly higher than in S1W (49%). Total N uptake in the plant tops was considerably lower in both the sprinkler-irrigated treatments when compared with CF, and this was mostly due to reduced soil N uptake in S3W (one-half) and S1W (one-third). The proportion of N derived from fertilizer in the plant tops increased from 40% in CF to 60% in S1W. Immobilization of applied N in the soil of the sprinkler-irrigated treatments was greater than in CF by factors of 1.5 (S3W) and 2 (S1W). Immobilization of urea N applied 36 DAE was almost 50% greater than immobilization of urea N applied 84 DAE. There was a trend for lower losses of fertilizer N with sprinkler irrigation (mean loss 18% of the applied N) compared with CF (27%). Within all irrigation treatments, the loss from urea applied 36 DAE was more than double the loss from urea applied 84 DAE. An additional study in CF compared the ¹⁵N balance for split application versus a single dose applied 36 DAE (before permanent flood). Split application resulted in significantly increased plant recovery of applied ¹⁵N, and this was largely associated with increased recovery in the grain. Slightly more fertilizer N was immobilized in the soil with a single application. The effect of application method on N loss was not significant.  相似文献   

The growth and nitrogen economy of rice under sprinkler and flood irrigation in South East Australia     

E. Humphreys  W. A. Muirhead  F. M. Melhuish  R. J. G. White  J. Blackwell 《Irrigation Science》1989,10(3):201-213

Summary Dry-seeded rice (Oryza sativa L., cv. Calrose) was subjected to 4 irrigation treatments — continuous flood (CF) and sprinkler irrigation at frequencies of one (S1 W), two (S2W) and three (S3W) applications per week — commencing 37 d after 50% emergence (DAE). The amount of water applied was calculated to replace water lost by pan evaporation. Urea (120 kg N ha^–1) was applied in a 1:1 split 36 and 84 DAE, and there were also unfertilized controls for each irrigation treatment. Amounts of nitrate (NO ₃ ^– ) in the soil were very low throughout the growing season in all treatments, despite regular periods of draining which lasted for up to 7 d in SlW. In all irrigation treatments, the majority of the fertilizer nitrogen (N) was located in the top 20 mm of soil. After each application of fertilizer, levels of mineral N in CF declined rapidly, while levels in S3W and S1W remained high for 1–2 weeks longer. The poor growth of sprinkler-irrigated rice was not due to lower amounts of mineral N in the soil. The greater persistence of fertilizer N in the sprinkler-irrigated treatments was probably due to reduced root activity near the soil surface because of frequent periods of soil drying in between irrigations. Net mineralization of soil N in the unfertilized sprinkler-irrigated treatments was reduced by about half compared with CF.On average, the quantity of water applied (1.2–1.4 × EP) to the sprinkler-irrigated treatments appeared to be sufficient to meet the evapotranspiration demands of the crop, except possibly around flowering time. However, the plants may have suffered from moisture stress in between irrigations. Soil matric potential data at 100 mm suggested little water stress in the sprinkler-irrigated treatments during the vegetative stage, consistent with the similar tiller and panicle densities in all irrigation treatments. However, the crop was stunted and yellow and leaf rolling was observed in the sprinkler-irrigated treatments during this period. Soil matric potential data at 100 mm indicated considerable water stress in S1W beyond the commencement of anthesis, and in S2W during grain filling, consistent with the reduced floret fertility and grain weight in those treatments.  相似文献   

Behaviour of domestic ducks exposed to mobile predator stimuli. 1. Flock responses     

Henderson JV  Nicol CJ  Lines JA  White RP  Wathes CM 《British poultry science》2001,42(4):433-438

1. Small flocks of ducks (Anasplatyrhynchos domesticus) were exposed to two stimuli, a small mobile vehicle and a walking human, to investigate their flight responses. 2. Experiment 1. Flocks were herded around an annular arena by each stimulus at 0.5 ms(-1) and the flight distance between the stimulus and the centre of the flock, and individual positions within the flock were recorded every 10 s. Flocks maintained a significantly longer distance from the human (6.0 m) than the vehicle (5.1 m) and usually did not maintain visual contact with either stimulus. Significant consistency in individual positions within the flock was found within and between trials. 3. Experiment 2. Flocks were exposed to each stimulus which approached them as they were feeding in a circular arena. The latencies for cessation and resumption of feeding were recorded and the paths followed by the flocks described. Ducks showed a significantly shorter latency to cease feeding in response to the human (4.9 s) compared with the vehicle (6.9 s). 4. Domestic ducks apparently perceive an approaching human as a greater threat than a small vehicle. The findings are discussed in relation to the development of herding robots.  相似文献   

Ultraviolet light and mating behaviour in domestic broiler breeders     

Jones EK  Prescott NB  Cook P  White RP  Wathes CM 《British poultry science》2001,42(1):23-32

1. The perception of UVA light (320 < lambda < 400 nm) by domestic fowl may be an adaptation to naturally lit habitats and may still be functional in farmed varieties, although not utilised owing to the absence of these wavelengths in commercial house lighting. One function may be the mediation of sexually related signalling or communication. 2. In experiment 1, two groups of 41 adult broiler breeders (four cockerels, 37 hens) were kept under conventional fluorescent light, with or without fluorescent UVA supplementation amounting to 16.9% of the total spectral power output of the luminaires. Each light environment was approximately iso-illuminant as perceived by the birds. The two groups were exposed to the light environments alternately for five 2-day periods in a cross-over design. Mating behaviour, production measures and time budgets were recorded on the second day of each period. 3. A UVA-enriched environment increased the number of attempted matings (1.27 vs 0.99 matings/cockerel.h) and locomotion (5.3 vs 3.7 min/bird.hour). 4. In a second experiment, 10 hens were allowed to choose between four cockerels lit under different power levels of UVA (1.6%, 14.6%, 43.5%, 57.5% of the total spectral power output of the luminaires) in a four-armed maze. Again, each light environment was approximately iso-illuminant as perceived by the birds. Each hen was allowed to make one choice per day over four days, with the position of the cockerels and the UVA levels interchanged each day. This schedule was repeated with the same hens for two other groups of four cockerels. 5. At a distance of no less than 60 cm from the cockerel, the hens spent most time inspecting whichever cockerel was lit by 1.6% or 14.6% UVA (1.33 vs 1.37 vs 1.22 vs 1.16 log seconds/hen.choice, respectively for increasing UVA level). Similarly, when allowed to approach closer to the cockerels, the hens spent most time in the arm which contained a cockerel lit by 14.6% UVA light, (1.62 vs 1.88 vs 1.69 vs 1.51 log s/hen.choice, respectively for increasing UVA level). 6. UVA is clearly implicated in the transmission of sexual signals or communication which may have implications for the welfare and production of broiler breeders.  相似文献   

Use of hyposensitization injections to control seasonal pruritus in a Bactrian camel (Camelus bactrianus).     

Laurie J Gage  Sophie I J Vandenabeele  Stephen D White 《Journal of zoo and wildlife medicine》2005,36(1):88-94

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