The sea louse Lepeophtheirus acutus (Caligidae, Siphonostomatoida, Copepoda) as a pathogen of aquarium-held elasmobranchs     

Kik MJ  Janse M  Benz GW 《Journal of fish diseases》2011,34(10):793-799

Lepeophtheirus acutus Heegaard, 1943 (Caligidae, Siphonostomatoida, Copepoda), was collected from or observed on four of six elasmobranch species held at Burgers’ Zoo (Arnhem, The Netherlands). Circumstantial evidence suggested that a zebra shark, Stegostoma fasciatum (Hermann), from the wild carried the infection into the facility, where copepods reproduced and colonized additional hosts. Copepods typically attached on and about the eyes, in the mouth and occasionally about the cloaca and on the claspers. Severe ocular lesions were associated with infections on zebra sharks, a grey reef shark, Carcharhinus amblyrhynchos (Bleeker), whitetip reef sharks, Triaenodon obesus (Rüppell), and giant shovelnose ray, Rhinobatos typus Bennett, while blacktip reef sharks, Carcharhinus melanopterus (Quoy & Gaimard), and blacktip sharks, Carcharhinus limbatus (Valenciennes), living in infested aquaria showed no sign of infection. Water treatments using trichlorfon were considered primarily responsible for the eradication of copepods from hosts and infested aquaria. This case is the first report of a copepod infection being closely associated with disease and death of an aquarium‐held elasmobranch. Given its ability to infect a wide variety of elasmobranchs and promote life‐threatening lesions on some hosts, L. acutus should be considered a dangerous pathogen of captive elasmobranchs.  相似文献   

Use of a staphylococcal vaccine to reduce prevalence of mastitis and lower somatic cell counts in a registered Saanen dairy goat herd     

F.M. Kautz  S.C. NickersonL.O. Ely 《Research in veterinary science》2014

This investigation evaluated the efficacy of a bacterin in reducing the prevalence of staphylococcal mastitis and somatic cell counts (SCC) in a dairy goat herd. Does were vaccinated or left as controls, and the levels of mastitis and SCC monitored over 18 months. Staphylococcus caprae (42.5%), S. xylosus (15.1%), and S. simulans (10.0%) were the predominant causes of intramammary infections (IMI). The infection rate was 1.64 IMI/doe among vaccinates, which tended to be lower (P < 0.12) than controls (2.67 IMI/doe). The spontaneous cure rate of IMI after immunization was 1.28 cures/doe in vaccinates, which was higher than controls (0.6 cures/doe; P < 0.043). Average SCC of milk samples from vaccinates tended to be lower than that of controls (1274 × 10³/ml vs. 1529 × 10³/ml, respectively) (P < 0.10). Results support the continued study of mastitis vaccines for use in managing staphylococcal mastitis and SCC in dairy goats.  相似文献   

Herd diagnosis of low pathogen diarrhoea in growing pigs – a pilot study     

Ken Steen Pedersen  Markku Johansen  ?ystein Angen  Sven Erik Jorsal  Jens Peter Nielsen  Tim K Jensen  Roberto Guedes  Marie St?hl  Poul B?kbo 《Irish veterinary journal》2014,67(1)

Background

The major indication for antibiotic use in Danish pigs is treatment of intestinal diseases post weaning. Clinical decisions on antibiotic batch medication are often based on inspection of diarrhoeic pools on the pen floor. In some of these treated diarrhoea outbreaks, intestinal pathogens can only be demonstrated in a small number of pigs within the treated group (low pathogen diarrhoea). Termination of antibiotic batch medication in herds suffering from such diarrhoea could potentially reduce the consumption of antibiotics in the pig industry. The objective of the present pilot study was to suggest criteria for herd diagnosis of low pathogen diarrhoea in growing pigs.Data previously collected from 20 Danish herds were used to create a case series of clinical diarrhoea outbreaks normally subjected to antibiotic treatment. In the present study, these diarrhoea outbreaks were classified as low pathogen (<15% of the pigs having bacterial intestinal disease) (n =5 outbreaks) or high pathogen (≥15% of the pigs having bacterial intestinal disease) (n =15 outbreaks). Based on the case series, different diagnostic procedures were explored, and criteria for herd diagnosis of low pathogen diarrhoea were suggested. The effect of sampling variation was explored by simulation.

Results

The diagnostic procedure with the highest combined herd-level sensitivity and specificity was qPCR testing of a pooled sample containing 20 randomly selected faecal samples. The criteria for a positive test result (high pathogen diarrhoea outbreak) were an average of 1.5 diarrhoeic faecal pools on the floor of each pen in the room under investigation and a pathogenic bacterial load ≥35,000 per gram in the faecal pool tested by qPCR. The bacterial load was the sum of Lawsonia intracellularis, Brachyspira pilosicoli and Escherichia coli F4 and F18 bacteria per gram faeces. The herd-diagnostic performance was (herd-level) diagnostic sensitivity =0.99, diagnostic specificity =0.80, positive predictive value =0.94 and negative predictive value =0.96.

Conclusions

The pilot study suggests criteria for herd diagnosis of low pathogen diarrhoea in growing pigs. The suggested criteria should now be evaluated, and the effect of terminating antibiotic batch medication in herds identified as suffering from low pathogen diarrhoea should be explored.

Electronic supplementary material

The online version of this article (doi:10.1186/2046-0481-67-24) contains supplementary material, which is available to authorized users.  相似文献   

对虾病原菌2—5B菌株16SrRNA基因片段的克隆和序列测定   总被引：2，自引：0，他引：2  

叶军  孔杰 《海洋水产研究》1997,18(1):9-15

用引物ＰＬ１－ＰＬ２ＰＣＲ扩增对虾病原菌－坎普氏弧菌２－５Ｂ菌株１６ＳｒＲＮＡ基因－１２２３ｂｐ的片段，采用ｐＵＣ１９质粒构建ｄＴ载体法完成该片段的克隆。部分序列测定及分析结果表明，该菌株与ＧｅｎＢａｎｋ中坎普氏弧菌标准株序列之间同源性为９６．９４％。  相似文献   

猪圆环病毒病原学研究进展     

王志军  ;郭慧娟  ;李秀丽  ;董树仁  ;鄢明华 《天津农业科学》2014,(8):68-71

猪圆环病毒(porcine circovirus,PCV)有2种不同的血清型,即猪圆环病毒1型(PCV1)和猪圆环病毒2型(PCV2)。目前研究表明PCV1暂无致病性,但PCV2则被认为是引起猪圆环疾病(PCVDs)的主要病原。很多地区养猪业的经济效益因此而遭受了重大的影响。PCV现已受到全球的关注,引起了许多专家学者的高度重视。本文对PCV的病原学最新研究进展进行了综述。  相似文献   

隐性乳房炎试验(CMT)及防治方案     

邱昌功  毛宏伟  逄国梁 《中国牛业科学》2014,(2):29-31

[目的]为找出陕西地区奶牛隐型乳房炎的临界点。[方法]采用生产上常用的乳房炎诊断方法,通过间接测定乳中体细胞数来诊断乳房炎的发生。[结果]找出体细胞数在47.46万以上时才依次表现出弱阳性、阳性、强阳性的特征。[结论]从而依据以上结果制定出两种方案用于预防和治疗乳房炎的发生。  相似文献   

甘肃加工型番茄叶果真菌病原鉴定及主要病害   总被引：1，自引：0，他引：1  

雷玉明  ;刘晓刚 《中国园艺文摘》2014,(7):39-41

经田间采集、分离培养、致病性测定,鉴定出13种加工型番茄真菌病原及病害。其中早疫病(Alternaria solani)、灰霉病(Botrytis cinerea)、叶霉病(Fulvia fulva)、斑枯病(Septoria lycopersici)、白霉病(Ramularia lycopersici)为甘肃省加工型番茄主要流行性病害,是制约甘肃省加工型番茄发展的主要病害。内丝白粉病(Leveillula brassicae)、柱隔孢菌(Ramularia lycopersici)侵染加工型番茄在国内外未见报道,属新病害。黑斑病(Alternaria brassicae)、果腐病(Fusarium moniliforme)、枯萎病(Fusarium oxysporium)、斑枯病(Septoria lycopersici)、煤污病(Cercospora fuligena)侵染加工型番茄在甘肃省属首次报道。  相似文献   

软包装即食醉鱼制品细菌学品质安全分析   总被引：1，自引：2，他引：1  

王哲恩  许钟  郭全友  杨宪时 《海洋渔业》2007,29(4):349-354

对上海市场常见品牌的软包装即食醉鱼制品感官、理化、细菌学品质状况进行定性和定量研究,并对潜在病原菌安全性进行评价。结果表明,产品水分含量、水分活度、pH和盐分含量分别为43.50%~56.97%,0.93~0.97,6.07~6.73,2.41%~6.63%,差别较大;细菌菌落总数、耐热菌落总数分别是1.8×102~4.2×105cfu/g,38~3 800 cfu/g;厌氧菌落总数和金黄色葡萄球菌均低于10 cfu/g。由细菌总数计数平板分离256株细菌,鉴定残存主要细菌菌群为芽孢杆菌(34.0%)、葡萄球菌(27.3%)、玫瑰小球菌(14.0%),并出现少量的棒状杆菌(5.5%),表明热杀菌强度不足。产品中残存有一定数量的蜡样芽孢杆菌,对其潜在危害有待进一步研究。  相似文献   

Hydrogen cyanide production by soil bacteria: Biological control of pests and promotion of plant growth in sustainable agriculture     

Anju SEHRAWAT  Satyavir S. SINDHU  Bernard R. GLICK 《土壤圈》2022,32(1):15-38

Currently, plant diseases and insect infestations are mainly controlled by the extraneous application of pesticides. Unfortunately, the indiscriminate use of such agrochemicals can cause ecological and environmental problems, as well as human health hazards. To obviate the potential pollution arising from the application of agrochemicals, biological control of soilborne pathogens or insect pests using antagonistic microorganisms may be employed. Certain soil bacteria, algae, fungi, plants and insects possess the unique ability to produce hydrogen cyanide(HCN), which plays an important role in the biotic interactions of those organisms. In particular, cyanogenic bacteria have been found to inhibit the growth of various pathogenic fungi, weeds, insects, termites and nematodes. Thus, the use of HCN-producing bacteria as biopesticides offers an ecofriendly approach for sustainable agriculture. The enzyme, HCN synthase,involved in the synthesis of HCN, is encoded by the hcnABC gene cluster. The biosynthetic regulation of HCN, antibiotics and fluorescent insecticidal toxins through the conserved global regulatory GacS/GacA system is elaborated in this review, including approaches that may optimize cyanogenesis for enhanced pest control. In addition, the effects of bacterially synthesized HCN on the production of indole acetic acid, antibiotics and fluorescent insecticidal toxins, 1-aminocyclopropane-1-carboxylate deaminase utilization and phosphate solubilization may result in the stimulation of plant growth. A more detailed understanding of HCN biosynthesis and regulation may help to elaborate the precise role of this compound in biotic interactions and sustainable agriculture.  相似文献   

植物病原效应蛋白功能研究方法   总被引：1，自引：0，他引：1  

何燕华 《现代农业科技》2014,(4)

植株病原会分泌一些与植物相互作用的效应蛋白,这些蛋白在病原菌与寄主植物互作过程中起着重要作用。结合几种细菌、真菌分泌的效应蛋白研究进展,介绍了用于病原菌效应蛋白研究的试验方法及其独特之处,包括图位克隆、异源表达分析等,提出研究一个单一效应蛋白需要多种分析方法。  相似文献