丝状支原体簇和多杀性巴氏杆菌双重PCR方法的建立及应用

本研究旨在建立丝状支原体簇和多杀性巴氏杆菌的双重PCR检测方法,从而为临床上同时检测这2类病原的感染提供一种更方便、快捷、准确的工具。本研究采用2对特异性检测丝状支原体簇和多杀性巴氏杆菌的引物,对PCR反应体系和反应条件进行了优化,并对双重PCR的特异性及敏感性进行了评价,随后采用该方法对52份临床样本进行了检测。结果显示,所建立的双重PCR方法能同时扩增丝状支原体簇成员和多杀性巴氏杆菌的DNA,而对来源于其他常见病原的DNA均无扩增;对丝状支原体簇和多杀性巴氏杆菌的最低检测限分别为24.8和28.9 pg;能成功地从临床样本中检测丝状支原体簇成员和多杀性巴氏杆菌。结果表明,本研究所建立的双重PCR方法具有很好的特异性和敏感性,为临床丝状支原体簇和多杀性巴氏杆菌感染的快速诊断、病原鉴定及流行病学调查提供了有效的方法。     

广西山羊传染性胸膜肺炎病原的二重PCR快速诊断方法的建立

根据绵羊肺炎支原体标准株Y98和丝状支原体山羊亚种标准株PG3的16S rRNA两端的保守区序列设计了2对引物,建立了广西山羊传染性胸膜肺炎病原的二重PCR快速检测方法.试验结果显示,所建立的二重PCR能特异地扩增绵羊肺炎支原体和丝状支原体山羊亚种的基因片段,其敏感性可达lPg,,用建立的二重PCR检测了20份临床病例肺组织,检出率为70%(14/20),其中6份扩增出丝状支原体山羊亚种的基因片段,10份扩增出绵羊肺炎支原体的基因片段,有2份同时扩增出两种支原体的基因片段.培养法检出率为40%(8/20),而这8份病料均为PCR阳性.     

牛多杀性巴氏杆菌和牛支原体双重PCR检测方法的建立及应用

参照Gen Bank中牛多杀性巴氏杆菌kmt1基因序列(AF016259)和牛支原体opp D/F基因序列(AF130119),设计两对引物,在建立两种细菌单项PCR检测方法的基础上,优化双重PCR反应条件,建立了两种细菌的双重PCR检测方法,用这两对引物对同一样品中的牛多杀性巴氏杆菌、牛支原体核酸为模板进行双重PCR扩增,结果可同时扩增牛多杀性巴氏杆菌和牛支原体的265bp和439bp的特异性片段,而对其他4种牛病原菌的扩增结果均为阴性。敏感性测定结果表明,对牛多杀性巴氏杆菌和牛支原体的最低核酸检出限均为1pg。通过对30份临床病料检测,将建立的双重PCR技术和单项PCR方法进行对比验证,结果显示,两者的总符合率为100%。结果表明,建立的双重PCR检测方法具有特异、快速、准确的特点,可用于对牛多杀性巴氏杆菌和牛支原体的同时检测和鉴别诊断。     

多杀性巴氏杆菌和溶血性曼氏杆菌混合感染引起山羊肺炎的诊断

青海省湟中区某山羊场发生呼吸道疾病,为确定引起本次呼吸道疾病的病原,笔者对病死羊进行剖检,并进行病原分离、鉴定。同时,采用PCR方法,对多杀性巴氏杆菌、溶血性曼氏杆菌、绵羊肺炎支原体和丝状支原体等呼吸道相关病原进行分子检测。结果发现,患羊临床表现以咳嗽、呼吸困难、精神萎靡和鼻内有粘性分泌物为特征的肺炎,细菌分离获得多杀性巴氏杆菌和溶血性曼氏杆菌,未分离获得其他细菌性病原和支原体。PCR检测发现多杀性巴氏杆菌和溶血性曼氏杆菌阳性。根据临床症状、剖检变化和实验室检测,最后确诊为由多杀性巴氏杆菌和溶血性曼氏杆菌共同感染山羊引起的肺炎。     

山羊中绵羊肺炎支原体的分离及鉴定

从四川省乐至县发生胸膜肺炎性传染病的山羊群中采集12个鼻拭子及4个肺组织病料,进行病原分离培养和特异性PCR检测。结果从9个鼻拭子和4个肺组织中分离到支原体,经鉴定均为绵羊肺炎支原体,未发现丝状支原体簇成员及多杀性巴氏杆菌和溶血性曼氏杆菌。结果表明,绵羊肺炎支原体是引起该山羊群发生胸膜肺炎的病原,同时说明绵羊肺炎支原体也是山羊支原体性肺炎的重要病原之一。     

山羊传染性胸膜肺炎病原的分离鉴定

从内蒙古地区山羊病料中分离出疑似山羊传染性胸膜肺炎的病原,经染色镜检、生化鉴定、血清学等方法初步鉴定为山羊支原体山羊肺炎亚种.参照已知山羊支原体ADI基因设计的引物进行PCR扩增,通过电泳分析得到与文献报道相一致的大小为316 bp的条带,最终确定为山羊支原体山羊肺炎亚种.     

兔多杀性巴氏杆菌和支气管败血波氏杆菌双重PCR检测方法的建立及应用

根椐Gen Bank公布的兔多杀性巴氏杆菌16S r RNA和支气管败血波氏杆菌fim N基因序列,设计两对引物,在建立两种细菌单项PCR检测方法的基础上,优化双重PCR反应条件,建立了两种细菌的双重PCR检测方法,用这两对引物对同一样品中的兔多杀性巴氏杆菌、支气管败血波氏杆菌核酸为模板进行双重PCR扩增,结果可同时扩增兔多杀性巴氏杆菌和支气管败血波氏杆菌的258bp和449bp的特异性片段,而对其他4种兔病原菌的扩增结果均为阴性。敏感性测定结果表明,对兔多杀性巴氏杆菌和支气管败血波氏杆菌的最低核酸检出限分别均为1pg。通过对78份临床病料检测,将建立的双重PCR技术和单项PCR方法进行对比验证,结果显示,两者的总符合率为100%。表明建立的双重PCR检测方法,具有特异、快速、准确的特点,可用于对这兔多杀性巴氏杆菌和支气管败血波氏杆菌的同时检测和鉴别诊断。     

猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌复合PCR检测方法的建立

目的建立可以同时检测猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的快速而可靠的PCR检测方法。方法和结果根据胸膜肺炎放线杆菌的Apx-VIA基因序列、多杀性巴氏杆菌和副猪嗜血杆菌的16SrRNA基因序列设计5条引物。猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌模板的PCR扩增产物大小分别为342bp,485bp和1258bp。复合PCR对1～12型猪胸膜肺炎放线杆菌标准株,6株多杀性巴氏杆菌标准株,1～15型副猪嗜血杆菌以及25株经生化鉴定确认为上述三种细菌的分离株的基因组DNA作为模板进行检测,均获得预期大小的扩增产物。以猪放线杆菌、吲哚放线杆菌等14种常见细菌作为阴性对照进行PCR检测,结果仅有支气管败血波氏杆菌产生了可以和上述三个特异性条带明显区分的PCR产物。复合PCR针对胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的敏感性分别为14pg、34pg和37pg。结论本研究建立的复合PCR特异性好,敏感性高,可以用于猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的快速检测。     

D型多杀性巴氏杆菌和绵羊肺炎支原体引起山羊的混合感染

2018年9月广西某羊场部分山羊发生流涕、咳嗽、呼吸困难和体温升高等临床症状的疾病,为确诊发病原因并提供治疗方案,采用病原分离培养、PCR扩增鉴定的方法进行诊断,并对分离菌进行生化鉴定、致病性试验和药敏试验。结果显示,病料在血平板有圆形的小菌落生长,革兰阴性小球短杆菌,而在PPLO培养基上不生长;病料的PCR扩增结果显示绵羊肺炎支原体和多杀性巴氏杆菌均为阳性;所分离到的病原菌经生化鉴定,该菌符合多杀性巴氏杆菌的特性;用多杀性巴氏杆菌种属和D型多杀性巴氏杆菌特异性引物扩增为阳性;致病性试验显示该菌对小鼠有很强的致病性;药敏试验显示该菌对头孢他啶、头孢噻肟、氧氟沙星高度敏感,对复方新诺明、强力霉素、红霉素、青霉素为耐药。结果表明该病是由绵羊肺炎支原体和D型多杀性巴氏杆菌混合感染引起。     

猪肺炎支原体PCR诊断方法的建立

建立了一个PCR检测猪肺炎支原体(Mhp)的方法。根据国外发表Mhp 16sr RNA基因设计了一对特异性引物，扩增出一个大小为653bp的特异性片段。将PCR产物克隆并测序表明，与GenBank的Mhp的序列的同源性为89．2％。而对于常见的猪呼吸道疾病有关的病原胸膜肺炎放线杆菌、支气管败血波氏杆菌、多杀性巴氏杆菌以及牛支原体、羊支原体不能扩增出特异性片段；PCR的敏感性实验显示这对引物能够检测到1ng的DNA，结果表明此方法特异、敏感。     

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