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

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.     

国有苗圃所有制结构调整之我见

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.     

3种阔叶树育苗技术及苗木生长规律研究初探

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。     

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

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.     

阔叶红松林山杨伐根分解过程中真菌动态研究

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.     

种间关系对中条山油松人工林天然更新及群落稳定性的影响

[目的]为了揭示种间关系对中条山油松人工林天然更新及群落稳定性的影响,为油松人工林经营管理提供理论依据.[方法]基于中条山油松人工林群落样地调查数据,分析油松人工林下主要植物的种间关联性、生态位重叠及群落稳定性,并在此基础上探讨种间关联和生态位理论在油松人工林天然更新障碍及群落稳定性形成机制中的作用.[结果]中条山油松...     

Uterine adenomyosis in an orang-utan (Pongo abelii/pygmaeus)

A 48-year-old, multiparous, female hybrid orang-utan ( Pongo abelii/pygmaeus ) was investigated after a 3-year history of irregular and excessively heavy menstrual bleeding. Opportunistic pelvic examinations over a 2.5-year period were non-diagnostic. Medical therapy was not effective. A subtotal hysterectomy with bilateral salpingo-ovariectomy was performed. A pedunculated mass spanning 90% of the uterine lumen was seen grossly, and histopathology confirmed uterine adenomyosis. Adenomyosis is defined as the ectopic occurrence or diffuse implantation of endometrial tissue, including glands and stroma, into the myometrium. It is common in older, usually premenopausal, multiparous women and is frequently associated with other uterine pathology, including endometrial hyperplasia and leiomyomas. The most common clinical signs are dysmenorrhoea and heavy menstrual bleeding; however, up to 35% of women are asymptomatic. Diagnosis is difficult and requires myometrial sampling and an experienced pathologist. A hysterectomy in this case was diagnostic and curative. There have been few reports of uterine adenomyosis in non-human primates and none reported in an orang-utan. Uterine adenomyosis should be considered in the differential diagnosis in any multiparous, aged, non-human female primate with irregular and excessively heavy menstrual bleeding, and hysterectomy with bilateral salpingo-ovariectomy is recommended as a diagnostic and therapeutic solution.     

红松伐根分解过程中真菌动态研究

对分解过程中红松伐根上着生的大型真菌子实体进行了研究,分析其变化动态,结果表明,在分解过程中,红松伐根上着生的大型真菌子实体种类较多,共涉及14个科,其中以层菌纲伞菌目的真菌数量最多;伐根上大型真菌的数量随分解时间的增加而增加,但是多样性却随分解时间的递增而降低,表明红松伐根上的真菌有随分解时间的增加而汇聚的现象;不同真菌在红松伐根分解过程中出现的时间不同,白蘑科和侧耳科是红松伐根分解过程中最常见的真菌类群.     

4个晒烟品种在广昌县的种植表现

为筛选适合广昌县种植的优良、高抗晒烟品种,以赤水铁赤烟、驿前铁赤烟、杨溪木勺烟和头陂柳叶烟4个晒烟品种为材料,采用田间试验对其在广昌县种植的大田生育期、农艺性状、发病率、经济性状、化学成分及感官质量进行观察评价。结果表明:赤水铁赤烟的大田生育期最长,为120d;驿前铁赤烟其次,为119d;杨溪木勺烟最短,为114d。赤水铁赤烟的农艺性状、经济性状和产质量均优于另外3个品种,且对花叶病的抗性较强;驿前铁赤烟对赤星病的抗性最强,其他综合性状仅次于赤水铁赤烟;而杨溪木勺烟和头陂柳叶烟的综合表现均较差。赤水铁赤烟和驿前铁赤烟可在当地作为优良晒烟品种进行大面积推广应用,杨溪木勺烟和头陂柳叶烟建议作为晒烟种质资源材料利用或改良后再进行试种观察。     

机电设备安装运行的异常现象及对策

目前,由于国产设备的技术水平和加工水平,与国外的技术设备有较大的差距,关键设备大多引进国外技术设备,其整体及配件价格十分昂贵.为了提高企业经济效益,这就要求机电设备维护人员对设备的一些异常现象,做到分析原因提出解决对策,降低设备故障减少设备维修费用.