Death of a neonatal lamb due to Clostridium perfringens type B in New Zealand     

JS Munday  H Bentall  D Aberdein  M Navarro  FA Uzal  S Brown 《New Zealand veterinary journal》2020,68(4):242-246

ABSTRACT

Case history and clinical findings: A flock of 20 sheep was kept within three paddocks on a single property. None of the animals in the flock had been vaccinated against any disease for at least three years. Abdominal bloating and haemorrhagic diarrhoea were observed in Lamb 1 at 24 hours-of-age. The lamb subsequently died within an hour of the onset of clinical signs. Lamb 2 was 3-days-old when observed to be recumbent with opisthotonus. The lamb was treated with dextrose, vitamins B1 and B12, and penicillin G, but died 4 hours later.

Pathological findings: Examination of Lamb 1 revealed markedly increased gas within the peritoneum and within dilated loops of intestine. The intestines were dark red and contained large quantities of haemorrhagic fluid. Histology of the intestines revealed peracute mucosal necrosis with minimal accompanying inflammation. The intestinal lumen contained cell debris, haemorrhage, and myriad large Gram-positive bacilli. The intestines of Lamb 2 did not appear bloated or reddened. However, multiple fibrin clots were visible within the pericardial sac. Histopathological examination revealed small foci of necrosis within the mucosa of the distal intestine. The necrotic foci were often associated with large numbers of large Gram-positive bacilli.

Immunohistochemsitry and molecular biology: Intestinal samples from Lamb 1 were processed for Clostridium perfringens immunohistochemistry, which revealed large numbers of intralesional, positively immunostained rods. Fragments corresponding to the expected sizes for genes encoding alpha, beta, and epsilon C. perfringens typing toxins were amplified by PCR from DNA extracted from formalin-fixed sections of intestine.

Diagnosis: Lamb dysentery due to C. perfringens type B.

Clinical relevance: C. perfringens bacteria have a worldwide distribution, but disease due to C. perfringens type B has only been diagnosed in a small number of countries and has never been reported in New Zealand or Australia. C. perfringens type B produce both beta toxin and epsilon toxins, therefore both haemorrhagic enteritis and systemic vascular damage can develop. As many animals are exposed to C. perfringens without developing disease, there must be additional unknown factors that resulted in disease in these particular sheep. Vaccines that specifically protect against C. perfringens type B are available and may be recommended for use in smaller non-commercial flocks, as in the present case.  相似文献   

国有苗圃所有制结构调整之我见     

周国平  李发凯 《江西林业科技》2001,(Z1)

所有制结构的调整是国有苗圃发展壮大的出路所在.笔者从必要性,战略方向,基本途径等三个方面阐述了看法.  相似文献   

3种阔叶树育苗技术及苗木生长规律研究初探   总被引：2，自引：0，他引：2  

刘志强  肖水清  邹元熹  肖才发 《江西林业科技》2001,(3):14-15

通过对闽楠，蓝果树，东京野茉莉的育苗试验，研究苗木生长规律，掌握生理生物学特性。  相似文献   

The effect of feeding three anabolic steroids in different combinations on the growth,food conversion efficiency and protein and nucleic acid levels of liver,kidney, brain and muscle of mirror carp (Cyprinus carpio)     

Khalid P. Lone 《Fish physiology and biochemistry》1989,6(3):149-156

A study on the effect of three different anabolic-androgenic steroids on the growth, food conversion efficiency and nucleic acid contents of liver, kidney, brain and muscle of carp,Cyprinus carpio was undertaken. The three steroids, methyltestosterone (MT), ethylestrenol (EE) and oxandrolone (ON), were fed in different combinations at final concentrations of 5 or 6 mg/kg diet for 60 days. No effect on the growth was observed in any of the experimental groups. A decrease in the specific growth rate (11–21%) and food conversion efficiency (20–29%) was noted. Feeding of drugs increased the cranio-somatic and reno-somatic index in all except one group. Hepatosomatic (ON+MT) and viscero-somatic (ON+MT; EE+MT+ON) indices decreased. Protein increased and RNA/DNA decreased in only one group while a decrease in protein/DNA was observed in the liver of all experimental groups. RNA/DNA increased and protein/RNA decreased only in one group while no effect was seen in protein and protein/DNA contents in any of the treated kidneys. Proteins, protein/RNA and protein/DNA decreased in certain groups in brain tissue. In muscle, no effect was seen in proteins or protein/DNA. Protein/RNA decreased in all but one group while RNA/DNA was higher only in the group fed all the three steroids together.  相似文献   

Global and Phylogenetic Distribution of Quorum Sensing Signals,Acyl Homoserine Lactones,in the Family of Vibrionaceae     

Bastian Barker Rasmussen  Kristian Fog Nielsen  Henrique Machado  Jette Melchiorsen  Lone Gram  Eva C. Sonnenschein 《Marine drugs》2014,12(11):5527-5546

Bacterial quorum sensing (QS) and the corresponding signals, acyl homoserine lactones (AHLs), were first described for a luminescent Vibrio species. Since then, detailed knowledge has been gained on the functional level of QS; however, the abundance of AHLs in the family of Vibrionaceae in the environment has remained unclear. Three hundred and one Vibrionaceae strains were collected on a global research cruise and the prevalence and profile of AHL signals in this global collection were determined. AHLs were detected in 32 of the 301 strains using Agrobacterium tumefaciens and Chromobacterium violaceum reporter strains. Ethyl acetate extracts of the cultures were analysed by ultra-high performance liquid chromatography-high resolution mass spectrometry (MS) with automated tandem MS confirmation for AHLs. N-(3-hydroxy-hexanoyl) (OH-C6) and N-(3-hydroxy-decanoyl) (OH-C10) homoserine lactones were the most common AHLs found in 17 and 12 strains, respectively. Several strains produced a diversity of different AHLs, including N-heptanoyl (C7) HL. AHL-producing Vibrionaceae were found in polar, temperate and tropical waters. The AHL profiles correlated with strain phylogeny based on gene sequence homology, however not with geographical location. In conclusion, a wide range of AHL signals are produced by a number of clades in the Vibrionaceae family and these results will allow future investigations of inter- and intra-species interactions within this cosmopolitan family of marine bacteria.  相似文献   

Use of dietary supplements in Denmark is associated with health and former smoking     

Knudsen VK  Rasmussen LB  Haraldsdóttir J  Ovesen L  Bülow I  Knudsen N  Jørgensen T  Laurberg P  Perrild H 《Public health nutrition》2002,5(3):463-468

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Beta-thujaplicin: new quantitative CZE method and adsorption to goethite     

Dyrskov L  Strobel BW  Svensmark B  Hansen HC 《Journal of agricultural and food chemistry》2004,52(6):1452-1457

Beta-thujaplicin (beta-TH) is a toxic tropolone derivative present in the heartwood of western red cedar (Thuja plicata) and is used as a preservative and antimicrobial additive in a number of commercial goods. beta-TH released from western red cedar timber used outdoor and from other products containing beta-TH may transfer to soil and leach to groundwater and surface waters. The objective of this study was to quantify the adsorption of beta-TH to goethite as a typical model for geosorbents. Adsorption was studied using pH-adjusted goethite suspensions with solid:solution ratios of 1:500, 0.01 M NaNO(3) electrolyte, and 20 degrees C. beta-TH was determined using a new capillary zone electrophoresis (CZE) method providing a detection limit of 0.21 microM. Near-sorption equilibrium was attained within 48 h. beta-TH showed maximum adsorption at low pH (3.8) and a 70% drop in adsorption from pH 6.2 to 8.8. The Langmuir type adsorption isotherm at pH 5.5 approached a maximum adsorption of 220 micromol/g (= 6.2 micromol/m(2)), which is more than twice the amount of phosphate adsorbed under similar conditions. The affinity of beta-TH for goethite is low as compared with organic ligands such as citrate, oxalate, and 2,4-dihydroxybenzoate. The adsorption data and FTIR analyses indicate that beta-TH is most likely adsorbed as monodentate mononuclear surface complexes at the surface of goethite. Hydrophobic adsorption is thought to contribute to the adsorption, in particular at low pH. The strong adsorption of beta-TH to goethite suggests low mobility in most soil environments, the risk of contamination increasing in soils with high pH (calcareous material), low contents of iron and aluminum oxides, phyllosilicates, and organic matter.  相似文献   

Analysis of embedded gas detection system based on nano-porphyrin arrays     

LUO Xiao gang  BAI Xing hong  HOU Chang jun  HUO Dan qun  FA Huan bao  YANG Mei 《保鲜与加工》2011,(12):48-53

In view of the necessity of gas detection in environment, an embedded gas detection system is designed based on the basic principles of chromatography change of chemical reaction between nano-porphyrin arrays and micro-gas, which takes ARM9 S3C2440A as the core and nano-porphyrin array as the sensors. The overall program, the circuit organization and control software of the main function module such as spectrum signal acquisition, processing and monitoring are presented. With energy conservation differential equation, the control model of temperature and flow rate in the sample chamber is established, which can precisely control the detection conditions of chemical sensors. Some typical trace gases such as ammonia, enanthaldehyde, cyclohexane and hexanal are tested by the system, and the results show that the system can achieve rapid and accurate detection of trace volatile gas.  相似文献   

阔叶红松林山杨伐根分解过程中真菌动态研究     

法蕾  赵秀海 《北京林业大学学报》2006,(Z2)

山杨是长白山阔叶红松林中的常见阔叶树种,择伐后的伐根很多.山杨伐根在多种真菌的作用下逐渐分解,不断地向周围释放养分,构成保证森林生态系统稳定循环的一个重要环节.随分解的不断进行,山杨伐根上的真菌的种类和数量都呈现出一定的变化趋势.真菌数量高峰出现在伐后的第5年,而种类高峰则出现在伐后的第7年.这一时间上的交错现象是由真菌的不同分解能力引起的.分解能力强的主要分解菌将难于分解的木质素、纤维素等分解为易于利用的小分子物质,为其他真菌提供了营养来源,便于其他真菌的定殖.另外,伐根上的真菌数量还与伐根桩径呈正相关关系.  相似文献   

Epidemiology. The epidemiologist's dream: Denmark     

Frank L 《Science (New York, N.Y.)》2003,301(5630):163

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