Faeces as a novel material to estimate lyssavirus prevalence in bat populations     

Lineke Begeman  Engbert A. Kooi  Erik van Weezep  Marco W. G. van de Bildt  Chantal B. E. M. Reusken  Peter H. C. Lina  Marion P. G. Koopmans  Judith M. A. van den Brand  Thijs Kuiken 《Zoonoses and public health》2020,67(2):198-202

Rabies is caused by infection with a lyssavirus. Bat rabies is of concern for both public health and bat conservation. The current method for lyssavirus prevalence studies in bat populations is by oral swabbing, which is invasive for the bats, dangerous for handlers, time‐consuming and expensive. In many situations, such sampling is not feasible, and hence, our understanding of epidemiology of bat rabies is limited. Faeces are usually easy to collect from bat colonies without disturbing the bats and thus could be a practical and feasible material for lyssavirus prevalence studies. To further explore this idea, we performed virological analysis on faecal pellets and oral swabs of seven serotine bats (Eptesicus serotinus) that were positive for European bat 1 lyssavirus in the brain. We also performed immunohistochemical and virological analyses on digestive tract samples of these bats to determine potential sources of lyssavirus in the faeces. We found that lyssavirus detection by RT‐qPCR was nearly as sensitive in faecal pellets (6/7 bats positive, 86%) as in oral swabs (7/7 bats positive, 100%). The likely source of lyssavirus in the faeces was virus excreted into the oral cavity from the salivary glands (5/6 bats positive by immunohistochemistry and RT‐qPCR) or tongue (3/4 bats positive by immunohistochemistry) and swallowed with saliva. Virus could not be isolated from any of the seven faecal pellets, suggesting the lyssavirus detected in faeces is not infectious. Lyssavirus detection in the majority of faecal pellets of infected bats shows that this novel material should be further explored for lyssavirus prevalence studies in bats.  相似文献   

Norovirus outbreak in a natural playground: A One Health approach     

Gregorius J. Sips  Mariëlle J. G. Dirven  Joke T. Donkervoort  Francien M. van Kolfschoten  Claudia M. E. Schapendonk  My V. T. Phan  Annemieke Bloem  Anna F. van Leeuwen  Mariechristine E. Trompenaars  Marion P. G. Koopmans  Annemiek A. van der Eijk  Miranda de Graaf  Ewout B. Fanoy 《Zoonoses and public health》2020,67(4):453-459

Norovirus constitutes the most frequently identified infectious cause of disease outbreaks associated with untreated recreational water. When investigating outbreaks related to surface water, a One Health approach is insightful. Historically, there has been a focus on potential contamination of recreational water by bird droppings and a recent publication demonstrating human noroviruses in bird faeces suggested this should be investigated in future water‐related norovirus outbreaks. Here, we describe a One Health approach investigating a norovirus outbreak in a natural playground. On social media, a large amount of waterfowl were reported to defecate near these playground premises leading to speculations about their potential involvement. Surface water, as well as human and bird faecal specimens, was tested for human noroviruses. Norovirus was found to be the most likely cause of the outbreak but there was no evidence for transmission via waterfowl. Cases had become known on social media prior to notification to the public health service underscoring the potential of online media as an early warning system. In view of known risk factors, advice was given for future outbreak investigations and natural playground design.  相似文献   

福尔马林消毒剂对养殖场粪污产沼气的影响     

张京景  苏有勇  孔琳  陈飞  李昊 《农业工程学报》2011,27(13):64-67

以猪粪为发酵原料,研究消毒剂福尔马林对沼气发酵的影响,以期为养殖场粪污产沼气发酵处理提供技术指导。研究结果表明,消毒剂福尔马林对沼气发酵有抑制作用,使沼气发酵体系的挥发性总脂肪酸含量和脂肪酶活性增加,α-淀粉酶和纤维素酶的活性降低,产气量下降。随着添加量增加,这种变化趋势增强,当添加量达到0.05%时,挥发性总脂肪酸含量增加18.78%,脂肪酶活性提高135.13%,α-淀粉酶和纤维素酶的活性分别下降78.57%和83.65%。研究结果从机理上解释了养殖场粪污进行沼气发酵处理时,出现产气量下降甚至不产气的原因。可为养殖场粪污沼气发酵处理提供一定的技术指导,以保证沼气发酵的正常进行。  相似文献   

象山港网箱养殖鲈鱼残饵和排粪情况初步研究   总被引：2，自引：0，他引：2       下载免费PDF全文

卓华龙  沈庞幼  吴雄飞  李家乐 《上海海洋大学学报》2007,(5):443-447

通过对象山港典型网箱养殖区,养殖鲈鱼投饵、摄食情况的研究,推算残饵和排粪情况。结果表明,鲈鱼年平均摄食率以饵料湿重计为2.6%,以饵料干重计为0.6%。全年投入象山港养殖网箱中的饵料以湿重计为143335.5 t,平均每天投392.7 t,以干重计为31 045.5 t,平均每天投85 t。鲈鱼的排粪率以颗粒有机碳POC干重计平均为6.5%,象山港网箱养殖鱼类每天排粪量干重为7.5 t,全年为2 737.5 t。鲈鱼对饵料的平均利用率为71.8%,全年网箱养鱼的残饵量湿重为43 252.5 t,每天平均118.5 t;以干重计为9 548.4 t,平均每天为26.16 t。显示残饵和排粪量对养殖区底质和水质污染比较严重。  相似文献   

Adsorption of pentachlorophenol by soils     

Jyung Choi  Shigenori Aomine 《Soil Science and Plant Nutrition》2013,59(2):135-144

The adsorption studies using soils various in the species of clay minerals and organic matter content indicate:

1) That apparent adsorption occurs to the greatest extent on the strong acid soil system compared to the moderate acid soil system, regardless of the species of clay mineral and organic matter content. And there is no adsorption on the slightly acid or neutral soil system.

2) The apparent adsorption involves adsorption of molecules and/or anions and precipitation of molecules in the micell and the external liquid phase.

3) The magnitude of adsorption occurs in the decreasing order of humus-allophanic, allophanic, montmorillonitic, and halloysitic soils.

4) The major factor governing the magnitude of apparent adsorption is pH.  相似文献   

Type of dietary fibre (soluble versus insoluble) influences digestion, faeces characteristics and faecal waste production in Nile tilapia (Oreochromis niloticus L.)     

Abdolsamad K Amirkolaie  Jascha I Leenhouwers  Johan A J Verreth  & Johan W Schrama 《Aquaculture Research》2005,36(12):1157-1166

The physico‐chemical properties of nutrients influence the physical characteristics of faeces and thus may affect waste removal efficiency. The aim of this study is to assess the effect of type of non‐starch polysaccharide (NSP) on digesta viscosity, faeces recovery and nutrient digestibility in Nile tilapia. Insoluble (cellulose) and soluble (guar gum) NSPs were included separately and combined at a level of 8%, thereby formulating four experimental diets. The diets were assigned to 16 tanks with 35 fish each, with four replicates for each diet. Cellulose inclusion did not influence digesta viscosity, growth and digestibility of protein and starch and tended to increase faeces recovery (P=0.06). Guar gum inclusion increased digesta viscosity and reduced the growth and digestibility of protein, fat and starch (P<0.01). Faeces recovery was reduced by 42% in diets containing guar gum. There were interaction effects (P<0.05) between cellulose and guar gum for the growth and feed conversion ratio, indicating that cellulose alleviated the negative impact of guar gum. In conclusion, dietary soluble NSPs increase organic matter load in the culture system through a reduction in faeces recovery and nutrient digestibility, whereas insoluble NSPs improve the removal efficiency of particles by increasing faeces recovery.  相似文献   

联合提取蚕沙中果胶和叶酸的研究     

李富兰  颜杰  郭金全  李莉 《蚕桑通报》2010,41(2):18-21

对从蚕沙中联合提制叶酸和果胶进行了研究。结果表明:以活性炭15g为吸附剂,吸附时pH为5.5,解吸剂以3%的氨水-70%乙醇溶液最佳,叶酸产率为0.14%左右,蚕沙叶酸的产品质量达到国家标准GB7302-87。果胶的最佳工艺条件:沉析时pH为3.5,沉析温度60℃,沉析时95%乙醇用量和浓缩液的比值为1.1为宜,果胶产品质量达到国家标准GBn246-85。  相似文献   

Detection of salmon pancreas disease virus in the faeces and mucus of Atlantic salmon,Salmo salar L., by real‐time RT‐PCR and cell culture following experimental challenge     

D A Graham  A Brown  P Savage  P Frost 《Journal of fish diseases》2012,35(12):949-951

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Ingestion and excretion of nitrogen and phosphorus by beef cattle under contrasting grazing intensities     

R. J. Orr  B. A. Griffith  J. E. Cook  R. A. Champion 《Grass and Forage Science》2012,67(1):111-118

There is increased global interest in the environmental impacts of farming, including the need to prevent the contamination of soil, water and air with excessive amounts of nitrogen (N) and phosphorus (P) in grazed systems. Reduction in grazing intensity has frequently been recommended to meet biodiversity and production goals in sustainable grazing systems. The objective of this experiment was to measure N and P ingestion and excretion by beef cattle grazing semi‐natural pastures at two grazing intensities (Moderate or Lenient). The cattle grazing at Moderate grazing intensity had significantly more defaecations each day than those grazing at Lenient intensity (9·5 vs. 7·5) and tended to have more urinations (7·0 vs. 5·8). For the Moderate and Lenient treatments, respectively, 113 vs. 76 g N d^?1 was excreted compared with 136 vs. 94 g N d^?1 ingested; 12 vs. 8 g P d^?1 was excreted compared with 13 vs. 10 g P d^?1 ingested and urine N comprised 0·51 and 0·52 of the total N excreted each day. In improved, intensively managed grassland systems, urine N comprises a much higher proportion (approximately 0·70–0·85) of the daily total N excreted. The lower level found here is likely to impact on potential volatilization, denitrification and leaching losses, and these aspects should be examined further to see the extent to which semi‐improved grasslands containing increased plant diversity compared with improved grasslands can deliver higher resource protection, as well as enhanced grassland faunal diversity and abundance.  相似文献   

Time related alterations in digestibility and faecal characteristics as affected by dietary composition in the Nile tilapia (Oreochromis niloticus L.)          下载免费PDF全文

A Keramat Amirkolaie  J W Schrama 《Aquaculture Research》2015,46(5):1078-1086

After being shifted to a new diet, time related alterations in digestibility, faecal waste production and faeces recovery in Nile tilapia were assessed in relation with dietary ingredient composition. Four experimental diets were formulated according to a 2 by 2 factorial design: two starch inclusion levels (20 or 40%) and two maize starch types (native versus gelatinized). After introduction to the experimental diets, faeces were collected weekly from Week 2 till 6 using settling tanks. Digestibility of ash, organic matter and dry matter increased with time (P < 0.001). For organic and dry matter the time related alteration in digestibility were different between both starch types (P < 0.05). All faecal waste characteristics altered with time (P < 0.01). The incline in faeces recovery with time was affected by starch type (P < 0.01); being the largest at the 40% gelatinized maize diet. In conclusion, the minimal length of the adaptation period in digestibility studies for obtaining unbiased digestibility estimates is dependent on diet composition, in this study with Nile tilapia 4 weeks for diets with gelatinized starch and 6 weeks with native starch.  相似文献