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31.
Alexander Sharp Elizabeth Smout Lisa Byrne Rebecca Greenwood Richard Abdoollah Charlotte Hutchinson Claire Jenkins Nachi Arunachalam Simon Padfield Gareth Hughes Mike Gent 《Zoonoses and public health》2020,67(5):467-473
In August 2018, Public Health England (PHE) was made aware of five probable cases of Shiga toxin‐producing Escherichia coli (STEC) O157:H7 among individuals reporting participation in a mud‐based obstacle race. An additional four cases, identified via routine whole‐genome sequencing, were subsequently linked to the same event. Two of the nine cases were due to secondary household transmission. Despite an agreement between the event organizers and the local authority, to ensure that all livestock were removed from the site 28 days before the event, sheep were observed grazing on some of the routes taken by the runners 2 days prior to the race taking place. A retrospective review of incidents reported to PHE between 2015 and 2018 identified 41 cases of gastroenteritis associated with muddy assault course events. Of these, 25 cases were due to infection with STEC O157:H7, of which all but one were associated with outbreaks. Due to the environment in which such events take place, it is impossible to entirely remove the risk of exposure to potentially pathogenic zoonoses. However, race organizers should ensure that livestock are removed from the course 28 days before the event. They should also ensure that participants are made aware of the risk of contracting gastrointestinal disease from the environment, and to stress the importance of hand hygiene post‐event and the risk of secondary transmission, particularly to children who are at risk of developing haemolytic uraemic syndrome. 相似文献
32.
Kannan Revathi Rajamanickam Chandrasekaran Annamalai Thanigaivel Suyambulingam Arunachalam KirubakaranSubbiah Sathish-Narayanan Sengottayan Senthil-Nathan 《Pesticide biochemistry and physiology》2013
The culture supernatant of a strain of Bacillus subtilis isolated from soil samples killed larvae of the mosquito Aedes aegypti. The metabolites produced by B. subtilis were characterized using high performance liquid chromatography (HPLC). Mortality rate was dose-dependent for all larval instars of A. aegypti. Log probit analysis (95% confidence level) revealed an LC50 of 1.73 and an LC90 3.71 μg/ml. Molecular weights/masses of B. subtilis metabolites were confirmed using SDS–PAGE analysis. B. subtilis metabolites were confirmed using HPLC analysis. We demonstrate that secondary metabolites from B. subtilis have larvicidal activity against A. aegypti and may be suitable for the control of this and other mosquito vectors of human disease. The larvae to the metabolites, significant reduction in the activities of acetylcholinesterse, α-carboxylesterase, and acid phosphatases were recorded. 相似文献
33.
In agricultural systems, especially where the soils are highly erodible, there is always a need for a better synchronization of nutrient release and nutrient demand by the growing crops. Management practices, such as conservation tillage could serve as a viable alternative to the mounting crisis and could enhance SOM besides other physicochemical properties. A field study was conducted in the rainfed agricultural system of northeast India with variedly tilled implements (indigenous spade, Country Plough, Bose Plough and Mouldboard Plough) from 2006 to 2007 to study the effect of these implements on the soils’ physiochemical properties during different growth phases of Oryza sativa in a rainfed valley agricultural system. A marked change in the bulk density values was observed up to 15–20 cm depth only in the Mouldboard Plough tilled plots. Over all, bulk density showed a significant positive correlation only with total N (r = 0.263, n = 30, p < 0.01). In all the study sites, a significant variation (p < 0.01) of soil moisture content with respect to time duration, tillage type and soil depth was observed. In Sites I and II, pH showed significant variation (p < 0.01) with time duration (F = 6.6, 3.0, d.f. = 5) and tillage type (F = 73.0, 48.5, d.f. = 4), respectively. Amongst all the study sites, Site II had comparatively higher value for soil organic matter followed by Sites III and I. Total N too showed variation with duration, tillage type and soil depth with ANOVA for the factors showing significant variation between and amongst them across the sites. Available P of the soil too varied remarkably along the crop's growing duration, its depth and upon the tillage method followed. Thus, our results suggest that conservation tillage, especially no-tillage, could serve as an effective tool with respect to increasing soil C and N sequestration in the subtropical agroecosystem of northeast India. 相似文献
34.
Dynamics of soil microbial biomass C, N and P in disturbed and undisturbed stands of a tropical wet-evergreen forest 总被引：6，自引：0，他引：6
A.R. Barbhuiya A. Arunachalam H.N. Pandey K. Arunachalam M.L. Khan P.C. Nath 《European Journal of Soil Biology》2004,40(3-4):113-121
To understand the spatial and temporal dynamics of soil microbial biomass and its role in soil organic matter and nutrient flux in disturbed tropical wet-evergreen forests, we determined soil microbial biomass C, N and P at two soil depths (0–15 and 15–30 cm), along a disturbance gradient in Arunachal Pradesh, northeastern India. Disturbance resulted in considerable increase in air temperature and light intensity in the forest and decline in the soil nutrients concentration, which affected the growth of microbial populations and soil microbial biomass. There were significant correlations between bacterial and fungal populations and microbial biomass C, N and P. Soil microbial population was higher in the undisturbed (UD) forest stand than the disturbed forest stands during post-monsoon and less during rainy season due to heavy rainfall. Greater demand for nutrients by plants during rainy season limited the availability of nutrients to soil microbes and therefore, low microbial biomass C, N and P. Microbial biomass was negatively correlated with soil temperature and pH in all the forest stands. However, there were significant positive relationships among microbial biomass C, N and P. Percentage contribution of microbial C to soil organic C was higher in UD forest, whereas percentage contribution of microbial biomass N and P to total N and total P was higher in the moderately disturbed site than in the highly disturbed (HD) site. These results reveal that the nutrient retention by soil microbial biomass was greater in the selective logged stand and would help in the regeneration of the forest upon protection. On the other hand, the cultivated site (HD) that had the lowest labile fractions of soil organic matter may recover at a slower phase. Further, minimum and maximum microbial biomass C, N and P during rainy and winter seasons suggest the synchronization between nutrient demand for plant growth and nutrient retention in microbial biomass that would help in ecosystem recovery following disturbance. 相似文献
35.
Arunachalam Thangasamy Kalyani Gorrepati T. P. Shabeer Ahammed R. Kavita Savalekar Kaushik Banerjee Sankar V 《Archives of Agronomy and Soil Science》2018,64(2):219-230
In an ongoing field experiment, organic and conventional farming (control) were compared for onion bulb yield, biochemical quality, soil organic carbon (SOC), and microbial activity after the sixth cropping cycle. The treatments used for organic production were farmyard manure (FYM, 20,000 kg ha?1), poultry manure (PM, 10,000 kg ha?1), vermicompost (VC, 10,000 kg ha?1), neem cake (NC, 5000 kg ha?1), and a combination of FYM (5000 kg ha?1), PM (2500 kg ha?1), VC (2500 kg ha?1), and NC (1250 kg ha?1); all treatments were compared with the control. Organic treatments produced 24.6–43.6% lower yield consistently for 6 years than the control treatment. No significant difference was observed between PM, FYM, and VC treatments for the bulb yield. Bulb analysis during the sixth year indicated that plants that received FYM, PM, or VC had higher levels of total phenol, total flavonoid, ascorbic acid, and quercetin-3-glucoside than the control plants. All the five organically treated sets had significantly higher values of SOC, microbial population, fungal-to-bacterial ratio, and dehydrogenase activity than the control and the initial values in each treated set. The results indicate that FYM, PM, or VC application enhances biochemical quality and organic farming is more sustainable than conventional farming. 相似文献