水稻纹枯病生防菌株的筛选、鉴定及其防治效果     

龙欣钰  孟祥佳  曹帅  MedisonRG  孙正祥  周燚 《植物保护学报》2022,49(6):1620-1630

为获得对水稻纹枯病有生防潜力的菌株,从湖北省恩施土家族苗族自治州植物根际土壤中分离获得菌株,筛选对水稻纹枯病菌有拮抗作用的菌株,并测定其发酵液的抑菌活性、抑菌谱及生物学特性;基于形态学特征、生理生化特征及分子生物学特征对其进行分类鉴定,并通过离体叶片、室内盆栽和田间试验进一步评价其生防潜力。结果显示,从根际土壤中共分离获得162株菌株,其中生防菌株E12对水稻纹枯病菌的抑制率最高,达94.93%,且该菌株对常见的12种植物病原菌均有抑制作用,抑制率在59.84%~93.14%之间;生防菌株E12能分泌蛋白酶、嗜铁素和淀粉酶,具有固氮及形成生物被膜的能力;结合形态学特征、生理生化特征及分子生物学特征,将菌株E12鉴定为越南伯克霍尔德氏菌Burkholderia vietnamiensis;生防菌株E12处理离体水稻叶片后,其相对病斑长度较对照显著减小,对水稻纹枯病的室内盆栽和田间防治效果分别为62.51%和67.78%。表明越南伯克霍尔德氏菌E12在防控水稻纹枯病方面有较好的潜力。  相似文献   

Intra-uterine transmission of Mycobacterium avium subsp paratuberculosis in subclinically affected red deer (Cervus elaphus)     

BR Thompson  RG Clark  CG Mackintosh 《New Zealand veterinary journal》2013,61(6):308-313

AIM: To determine the rate of transmission of Mycobacterium avium subsp paratuberculosis (M. ptb) from hind to fetus in utero, and the risk of transmission from dam to fawn via infected colostrum and milk in subclinically affected red deer hinds.

METHODS: Hinds were sourced from farms in Otago or Southland and selected for the study if they were positive to the immunoglobulin G1 (IgG1) modified enzyme-linked immunosorbent assay (ELISA) (Paralisa) and exhibited no clinical signs of Johne's disease. The hinds (n=35) were sent to a deer slaughter premises (DSP; n=31) or were killed on-farm (n=4). All post-mortem samples were collected from the fetus first and then from the dam, taking care to avoid cross contamination between samples. Fresh samples (n=185) were collected for culture, and tissue samples (n=72) were collected from 24 hinds and their fetuses for histopathological examination.

RESULTS: A total of 24/35 hinds selected were suitable for inclusion in the study. Eighteen of these pregnant hinds were culture-positive for M. ptb, and 14 of these had culture-positive fetuses, representing a transmission rate of 78% (95% confidence interval (CI) =0.58–0.98) from dam to fetus. Of the 16 mammary glands sampled, 11 (69%) were culture-positive for M. ptb while 12/15 (80%) mammary lymph nodes sampled were also culture-positive.

CONCLUSIONS: This study demonstrated a high rate of transmission of M. ptb from dam to fetus in red deer, and a potential risk of transmission to fawns suckling from mothers that are subclinically affected with Johne's disease.  相似文献   

Thysanoptera infestation on skin and periorbital cellulitis in ostriches (Struthio camelus) aged 14 months     

RG Cooper 《New Zealand veterinary journal》2013,61(3):130-133

AIM: To report the infestation of Thysanoptera (Limothrips denticornis) on ostriches (Struthio camelus) and to determine their relative density.

METHODS: A farm in Poland was studied on which ostriches aged 14 months were severely infested with L. denticornis (thrips). Thrips were collected and their density on the neck, torso and legs (10 cm²) of 85 ostriches determined at 0600, 1200 and 1800 h, respectively, over 7 days. At the same times, apparent densities of thrips/m² were determined in adjacent grassy areas (120 m²) on a muslin cloth impregnated with permethrin. Thrips were mounted onto slides in Hoyer's medium, for identification.

RESULTS: The apparent density of thrips was greatest at 1200 h, and was greater on the neck than the torso and legs (p=0.03). In adjacent surroundings, densities were also highest at 1200 h (mean 199 (SE 9.3) thrips/m²) and were similar to the maximum densities recorded on the necks of ostriches at that time (mean 205 (SE 6.4) thrips/m²). Ostriches engaged in excessive preening and attempted to scratch their head/neck with their feet. Numerous small, pale red papules were observed on the skin. Observations of periorbital cellulitis, conjunctivitis, blepharitis, watery discharge, inflammation, and sclerotic discolouration were noted in 65 ostriches.

CONCLUSION: Observations were commensurate with L. denticornis infestation.

CLINICAL RELEVANCE: Infestation may exacerbate stress levels and subsequently lead to a reduction in feed intake and performance. The infestation and subsequent irritation from thrips impacts negatively on the general health of ostriches by damaging skin and irritating eyes.  相似文献   

Purification of secretory immunoglobulin A from milk of the brushtail possum (Trichosurus vulpecula)     

EE Doolin  RG Midwinter  AR McCarthy  BM Buddle 《New Zealand veterinary journal》2013,61(5):181-186

AIM: To identify and purify secretory immunoglobulin A (sIgA), a key effecter molecule in mucosal immune responses, from milk of the brushtail possum (Trichosurus vulpecula).

METHODS: Milk samples were collected from female possums with pouch young, and clarified by centrifugation and precipitation methods. The clarified fraction was purified by gel filtration and affinity chromatography to yield sIgA. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting techniques were used to assess the purity of the final product, and to identify the heavy (H) chain, light (L) chain and secretory component (SC) of possum sIgA.

RESULTS: Immunoblotting, using antibodies raised against cloned possum sIgA SC and H-chain, and a synthetic peptide fragment of the H-chain, confirmed the identity of the purified protein. The N-terminal amino acid sequence of purified possum sIgA showed strong homology to reported sequences of H-chain variable regions of marsupial immunoglobulins.

CONCLUSIONS: Milk was shown to be a convenient source of mucosal secretion containing sIgA, and a process involving 2 precipitation and 2 chromatography steps produced purified sIgA. This IgA preparation will prove useful for the generation of sIgA-specific immunological reagents for measurement of immune responses in the development of mucosal-based vaccines for biological control of possums.  相似文献   

Listeria monocytogenes gastroenteritis in sheep     

RG Clark  JM Gill  S Swanney 《New Zealand veterinary journal》2013,61(1):46-47

Extract

Listeria monocytogenes is widely distributed in the environment of farm animals. It is found in soil, faeces and nasal secretions of healthy animals, water troughs and animal feeds. Under certain conditions it becomes pathogenic, causing serious disease in cattle and sheep. Most commonly it causes meningoencephalitis but, on occasion, septicaemic listeriosis results in abortion, and more recently it has been associated with gastroenteritis.  相似文献   

Pathology of brucellosis in rams in New Zealand     

J.L. Jebson  W.J. Hartley  T.J. McClure  D. McFarlane 《New Zealand veterinary journal》2013,61(3):100-104

A questionnaire-based case-control study investigating the association of a range of host-related, owner-related and environmental risk factors with feline lower urinary tract disease was conducted in New Zealand over a 2-year period from 1991 to 1993. The study was subsequently extended in two ways, to examine the influence of the use of litter trays and to correlate weather records with the appearance of the disease in one particular region of the country. A range of statistical techniques was employed to analyse the data, including univariate odds ratio and chi-squared calculations, time series analysis, Poisson regression and conditional and unconditional logistic regression. Variables that were positively associated with lower urinary tract disease included low activity levels, the use of a litter tray coupled with restriction indoors, a high number of rainfall days in the month preceding the appearance of clinical signs, stress factors such as moving house within the last 3 months or the presence of more than one cat in the household, and a diet high in dry cat food. There was some indication that high levels of fluid consumption reduced the effect of a diet high in dry cat food. Other variables that appeared to have some protective effects included a routine visit to the veterinarian in the last 12 months and the use of alternative food sources such as rodents and birds.  相似文献   

Some histological lesions seen in macroscopically normal mesenteric lymph nodes of deer     

RG Clark  JC Glossop  PR Wilson  C Heuer 《New Zealand veterinary journal》2013,61(1)

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Veterinary education     

David McFarlane 《New Zealand veterinary journal》2013,61(5):105-106

Extract

In a number of circumstances, helminthologicalstudies would be considerably facilitatedby the transfer of naturally-infected sheep from pasture to pens to enable them to be maintained without further re-infestation. However, at present few data are available concerning the effects of such a transfer upon the persistence and pattern of an existing infestation following the removal of the animals from the source of infection and the sudden marked change of diet. The present work provides information on this point.  相似文献   

Neutrophil and cytokine dysregulation in hyperinsulinemic obese horses     

Holbrook TC  Tipton T  McFarlane D 《Veterinary immunology and immunopathology》2012,145(1-2):283-289

Equine metabolic syndrome is characterized by obesity and regional adiposity coupled with evidence of recurrent laminitis. Although inflammation has been well characterized in several experimental models of acute laminitis, the inflammatory events associated with endocrinopathic laminitis are not well documented. The aim of this study was to characterize selected markers of inflammation in horses with clinical evidence of equine metabolic syndrome (EMS). Neutrophil phagocytosis and oxidative burst, as well as endogenous and stimulated cytokine expression were evaluated. A marked increase in neutrophil reactive oxygen species production upon phagocytosis was observed in horses with EMS that was strongly correlated to the blood insulin concentration. Increased oxidative burst activity of neutrophils in hyperinsulinemic horses may predispose horses with metabolic syndrome to laminitis. In contrast, peripheral blood cells of obese hyperinsulinemic horses showed decreased endogenous proinflammatory cytokine gene expression (IL-1 and IL-6) and similar cytokine response following immune stimulation compared to that of control horses. This may suggest that, unlike in people, cytokine-mediated inflammation does not increase in direct response to obesity or insulin resistance in horses. This species-specific disparity may explain the difference in clinical outcomes observed in obese horses compared to obese people.  相似文献   

More on cultivating veterinarian-scientists     

Hawkins E  Hall J  Cohn L  Buechner-Maxwell V  Oyama M  Barton MH  Olby N  Khanna C  Marks S  McFarlane D  Toll J 《Journal of the American Veterinary Medical Association》2010,237(12):1367

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