应用PCR方法检测奶牛乳房炎主要病原菌

为建立一种在分子水平快速检测乳房炎主要病原菌的方法,根据GenBank已发表的序列设计了3对特异性引物,结果可同时检测奶牛乳房炎的3种主要病原菌:金黄色葡萄球菌、大肠杆菌和无乳链球菌。其特异性为100%,敏感性检测的最低浓度为:1.25×103cfu/mL。     

陕西神木奶牛隐性乳房炎病原菌的分离鉴定及药敏试验

为了了解奶牛隐性乳房炎的主要病原菌及其对抗生素的敏感程度,从而为奶牛隐性乳房炎的有效防治和合理用药提供有利的理论依据。本研究采用兰州奶牛隐性乳房炎检测试剂(ILMT)方法对神木县某奶牛场51头奶牛200份奶样进行隐性乳房炎检测,选取强阳性乳样进行细菌分离鉴定,经革兰染色,生化试验鉴定,对主要病原菌采用纸片扩散法进行药物敏感性试验。结果表明,隐性乳房炎发病率为31.37%(16/51),乳区阳性率为17.5%(35/200);引起奶牛隐性乳房炎的病原菌主要有葡萄球菌,链球菌,肠杆菌3大类,且有两种病原菌的混合感染,其中耶尔森菌属和表皮葡萄球菌为主要病原菌;对3大类病原菌都敏感的抗生素药物有环丙沙星、四环素、头孢哌酮、庆大霉素、万古霉素5种药物,目前在临床上可选用此类药物治疗奶牛的隐性乳房炎。     

安徽部分地区奶牛乳房炎病原菌的分离鉴定和药敏试验

为了调查安徽地区奶牛乳房炎流行情况和筛选病原菌敏感药物.采集了安徽省奶牛主要养殖区的隐性乳房炎奶样,分离、鉴定了主要病原菌,并筛选了敏感药物.结果表明,乳房炎主要病原菌为金黄色葡萄球菌、大肠埃希菌和无乳链球菌,且2种或2种以上病原菌混合感染占大部分,这些主要病原菌对环丙沙星、恩诺沙星、头孢曲松钠和卡那霉素等抗菌药物高度敏感,为奶牛乳房炎的治疗药物的选择提供了直接依据.     

奶牛乳房炎分子诊断技术的研究进展

奶牛乳房炎是由病原微生物感染而引起的乳房组织及乳头发炎的一种疾病,它是造成奶牛业经济损失最主要的原因。在我国,每年用于治疗奶牛乳房炎的费用近亿元[1]。引起乳房炎的病原菌主要分为两类:一类是接触传染性病原菌,如金黄色葡萄球菌和无乳链球菌;另一类是环境性病原菌,如大肠杆菌。传统的检测方法主要依靠乳汁中微生物学培养和生     

奶牛乳房炎的分类、症状及诊治

1分类 以乳汁可否检出病原菌和乳汁有无肉眼可见变化划分为感染性临床型乳房炎、感染性亚临床型乳房炎、非特异性临床型乳房炎、非特异性亚临床型乳房炎。     

PCR诊断技术用于奶牛乳房炎病原菌快速检测的研究进展

奶牛乳房炎是一种严重影响奶牛业发展的常见多发病,不仅给乳品业造成巨大的经济损失,而且还影响乳品质量,危及人类健康。目前,对于奶牛乳房炎的治疗大部分奶牛场基本都是在不明确病原菌的情况下滥用抗生素,造成病原菌耐药性增加,治疗效果下降。为了有效治疗奶牛乳房炎,对奶牛乳房炎病原菌的早期快速诊断至关重要。由于传统的乳房炎病原菌的检测方法存在操作繁琐、耗时长、灵敏度低及无法检测抗生素乳样中病原菌等缺陷,因此,临床上急需一种快速、灵敏、简便的检测方法。作者对目前用于奶牛乳房炎病原菌诊断的普通PCR法、多重PCR法、实时荧光定量PCR法、巢氏PCR诊断法以及PCR检测试剂盒等进行了综述,并分析了这些方法的优缺点,同时对未来奶牛乳房炎病原菌诊断的研究方向和前景进行了展望,以期为进一步开发快速、特异、敏感的奶牛乳房炎病原菌诊断技术提供理论参考。     

湖羊乳房炎病原菌多重PCR检测方法的建立及其耐药性分析

为鉴定某规模化羊场患乳房炎母羊病原菌种类,构建病原菌多重PCR快速检测方法,分析其主要致病菌的耐药特征,对患临床型乳房炎湖羊乳样中乳房炎病原菌进行分离纯化和分子生物学鉴定,同时优化PCR体系,建立病原菌多重PCR快速鉴定方法,并进行药物敏感实验。结果显示,分离得到3种致病菌,共计28株,其中金黄色葡萄球菌14株,大肠杆菌10株,粪肠球菌4株;多重PCR方法能够特异稳定地扩增出目的条带,敏感性满足临床需要;药敏结果显示,3种病原菌对左氟沙星、庆大霉素、氯霉素、环丙沙星、诺氟沙星敏感,对氨苄西林、青霉素、红霉素有较强耐药性。该结果对于临床上绵羊乳房炎的快速诊断和防治有重要参考意义。     

乳房炎3种病原菌DNA提取方法比较研究

旨在比较3种DNA提取方法对山羊乳中致乳房炎主要病原菌DNA的提取效果及对PCR检测的影响.将不同浓度的金黄色葡萄球菌、无乳链球菌和大肠埃希氏菌加入羊乳中,并分别用硅胶膜试剂盒、酚/氯仿法和CTAB/NaCl法等3种方法提取总DNA,比较所获得DNA的浓度、纯度、所需时间和经济成本及对各病原特异性PCR检测的影响.结果...     

奶牛隐性乳房炎病原菌的分离及药敏试验

选择某牛场50头临床健康奶牛,采用CMT法进行隐性乳房炎检测,其中28头奶牛患有隐性乳房炎,发病率为56%;在被检的200个乳样中患有隐性乳房炎的乳区84个,乳区阳性率为42%。对阳性乳样进行细菌分离鉴定,从28头患有隐性乳房炎的奶牛的84个乳样中检出13种共98个菌株,其中葡萄球菌44个,占44.90%;金黄色葡萄球菌32个,占32.65%;链球菌20个,占20.40%;大肠埃希菌11个,占11.22%。由葡萄球菌、链球菌和大肠埃希菌引起的乳房炎占整个比例的75.51%。表明引起奶牛隐性乳房炎的病原菌以葡萄球菌、链球菌和大肠埃希菌为主,而且单纯由某一种病原菌引起的病例较少,多数是由2～3种甚至是3种以上的病原菌引起,混合感染率为83.33%。药敏试验结果表明,临床使用较多的青霉素和链霉素对奶牛乳房炎的主要病原菌有较强的耐药性,而对庆大霉素、丁胺卡那霉素、环丙沙星和林可霉素等药物则较为敏感。     

兰州地区奶牛乳房炎流行病学及病原菌调查

为了开展兰州地区奶牛乳房炎流行病学及病原菌的调查研究,试验应用LMT诊断液对兰州地区4个中等规模奶牛场的344头泌乳牛的1 237个乳区进行了隐性乳房炎检测,并对临床型乳房炎乳样进行了病原菌的分离鉴定。结果表明:奶牛隐性乳房炎的头阳性率为58.43%,乳区阳性率为36.86%;临床型乳房炎的头发病率为5.52%,乳区发病率为2.91%;主要病原菌检出率为无乳链球菌30.0%、大肠杆菌27.1%、金黄色葡萄球菌21.4%。说明兰州地区奶牛乳房炎发病率较高,病乳中无乳链球菌、大肠杆菌和金黄色葡萄球菌的检出率较高。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in