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41.
Feeding trials were carried out to assess the ability of a giant vampyrellid soil amoeba to attack and lyse spores of fungi. Of 24 species of fungi studies, 15 were perforated in the same manner as was reported for Cochliobolus sativus. This giant amoeba is nutritionally versatile and can feed on bacteria, flagellates, blue green algae, diatoms and nematodes. Seven other soil amoebae failed to lyse conidia of C. sativus.  相似文献   
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Conidia of Cochliobolus sativus and five other pigmented fungi lysed when incubated in natural soil. Lysis followed perforation of the spore wall by holes of varying dia. Three possible causes of perforation were investigated, namely autolysis, mechanical puncture by soil animals and enzymatic erosion by soil micro-organisms. Results indicated that soil micro-organisms were the likely causal agents although no micro-organism able to perforate conidia has yet been isolated. Colonization of conidia by the soil microflora was studied by electron microscopy. On the basis of these direct observations, possible perforation mechanisms are suggested. Reports of perforation of fungal, plant and bacterial cell walls are briefly summarized and the perforation phenomenon discussed in relation to the biodegradation of pigmented fungal propagules in soils.  相似文献   
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Macroconidia of Fusarium solani f. cucurbitae were placed into natural soil, incubated for various times, recovered and examined by light and transmission electron microscopy. Lysis of macroconidia and formation of chlamydospores were studied and the fine structure of these propagules and their associated microflora was investigated. The two most obvious features of chlamydospore morphology were the sloughing of outer wall layers and the accretion of micro-fibrillar elements adjacent to the plasmalemma. Chlamydospore formation was partially suppressed by addition of nitrogenous compounds to the soil.  相似文献   
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Two vaccines, based on formalin-killed whole cells of toxigenic Pasteurella multocida type D and Bordetella bronchiseptica combined with a partially toxoided cell extract of P multocida, were prepared with Freund's incomplete adjuvant (vaccine 1) or by alum precipitation (vaccine 2). Each was tested for safety and efficacy in reducing the severity of nasal turbinate atrophy and improving the growth rate of pigs in three Western Australian commercial piggeries with endemic atrophic rhinitis. In safety experiments with vaccine 1, no adverse clinical effects were observed in vaccinated sows or their progeny. Piglets receiving vaccine 2 showed no injection site abnormalities, pyrexia or turbinate atrophy. In field trials, vaccine 1 significantly reduced the prevalence of moderate to severe nasal turbinate atrophy (Done score 3 to 5) when used in two piggeries (A and B). Progeny from vaccinated sows in piggery B also grew significantly faster than controls. When vaccine 2 was used in piggery A at a later date and in another piggery (C), growth rate was not improved in either piggery and the prevalence of moderate to severe turbinate atrophy was reduced only in piggery C.  相似文献   
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With the commercial release in Australia in 2004 of a vaccine against feline immunodeficiency virus (FIV; Fel‐O‐Vax FIV®), the landscape for FIV diagnostics shifted substantially. Point‐of‐care (PoC) antibody detection kits, which had been the mainstay for diagnosing FIV infection since the early 1990s, were no longer considered accurate to use in FIV‐vaccinated cats, because of the production of vaccine‐induced antibodies that were considered indistinguishable from those produced in natural FIV infections. Consequently, attention shifted to alternative diagnostic methods such as nucleic acid detection. However, over the past 5 years we have published a series of studies emphasising that FIV PoC test kits vary in their methodology, resulting in differing accuracy in FIV‐vaccinated cats. Importantly, we demonstrated that two commercially available FIV antibody test kits (Witness? and Anigen Rapid?) were able to accurately distinguish between FIV‐vaccinated and FIV‐infected cats, concluding that testing with either kit offers an alternative to PCR testing. This review summarises pertinent findings from our work published in a variety of peer‐reviewed research journals to inform veterinarians (particularly veterinarians in Australia, New Zealand and Japan, where the FIV vaccine is currently commercially available) about how the approach to the diagnosis of FIV infection has shifted. Included in this review is our work investigating the performance of three commercially available FIV PoC test kits in FIV‐vaccinated cats and our recommendations for the diagnosis of FIV infection; the effect of primary FIV vaccination (three FIV vaccines, 4 weeks apart) on PoC test kit performance; our recommendations regarding annual testing of FIV‐vaccinated cats to detect ‘vaccine breakthroughs’; and the potential off‐label use of saliva for the diagnosis of FIV infection using some FIV PoC test kits. We also investigated the accuracy of the same three brands of test kits for feline leukaemia virus (FeLV) diagnosis, using both blood and saliva as diagnostic specimens. Based on these results, we discuss our recommendations for confirmatory testing when veterinarians are presented with a positive FeLV PoC test kit result. Finally, we conclude with our results from the largest and most recent FIV and FeLV seroprevalence study conducted in Australia to date.  相似文献   
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