猪胸膜肺炎放线杆菌PCR诊断方法的建立与应用

根据胸膜肺炎放线杆菌ApxⅣ基因设计1对引物，扩增特异的650bp棱酸片段，建立了应用PCR检测猪胸膜肺炎放线杆菌的方法。特异性试验结果表明，12个血清型的放线杆菌参考菌株均能扩增出650bp特异性的核酸片段，而大肠杆菌、多杀性巴氏杆菌、猪肺炎支原体、伤寒沙门氏菌和支气管败血性波氏杆菌的扩增结果均为阴性。敏感性试验结果表明，PCR的最低检出限量为500个放线杆菌。利用建立的PCR检测方法对22株从山东省不同地区分离的疑似胸膜肺炎放线杆菌菌株进行检测．结果14株为阳性。对感染猪病变组织的检测结果表明，病变部位不同，胸膜肺炎放线杆菌的检出率不同，其中以扁桃体的检出率最高。     

猪传染性胸膜肺炎放线杆菌PCR检测方法的建立及应用

猪传染性胸膜肺炎是由胸膜肺炎放线杆菌引起猪的一种高度接触性呼吸道传染病,该病可给养猪业造成巨大的经济损失。为有效控制和确诊该病,根据报道的猪胸膜肺炎放线杆菌APXIV毒株的基因序列,合成了2对可扩增长度分别为442 bp和378 bp的特异引物,建立检测胸膜肺炎放线杆菌的巢式PCR方法。利用合成的引物在扩增猪肺疫巴氏杆菌、猪链球菌、副猪嗜血杆菌和大肠杆菌等细菌DNA时,结果均为阴性。用引物检测猪胸膜肺炎放线杆菌的标准菌株可扩增出442 bp和378 bp的特异性条带。表明运用PCR法检测猪胸膜肺炎放线杆菌的特异性和灵敏性均较高,可作为猪传染性胸膜肺炎的快速诊断和流行病学调查的手段。     

猪传染性胸膜肺炎放线杆菌血清6型PCR方法的建立及初步应用

为了建立猪传染性胸膜肺炎放线杆菌血清6型分子鉴定方法,本研究根据胸膜肺炎放线杆菌从编码荚膜多糖的碱基序列设计1对引物,扩增特异性的720 bp核酸片段。结果表明,以APP为模板,均能扩增出与预期一致的1条720 bp核酸片段,所得PCR产物经测序,与Gen Bank已发表的胸膜肺炎放线杆菌血清型6型的同源性达99%以上。本研究建立了PCR检测猪传染性胸膜肺炎放线杆菌血清6型分子鉴定方法,该方法的建立为猪传染性胸膜肺炎放线杆菌病的诊断和防治及鉴定提供了基础。     

猪传染性胸膜肺炎PCR诊断方法的建立

根据已发表的猪胸膜肺炎放线杆菌APXIV毒素的基因序列，自行设计和合成了二对可扩增448bp和365bp目的片段的引物，成功的建立了检测APP的套式PCR方法。通过对猪肺疫巴氏杆菌、猪链球菌、大肠杆菌、猪嗜血杆菌、猪肺炎支原体和猪丹毒杆菌的DNA进行了PCR检测，结果均为阴性；对猪胸膜肺炎放线杆菌的1、2、5、6、7、9国际标准血清型均扩增出448bp和365bp的特异性条带；检测的敏感度一步PCR可达到5OO个细菌，最低检出DNA浓度可达到0．585ng／mL；套式PCR可达到50个细菌，最低检出DNA浓度可达到58．5pg／mL。另外，对5株从病猪体内分离的猪胸膜肺炎放线杆菌进行了检测，5株均成阳性反应；对10只屠宰猪的肺脏分离物进行了检测，结果1份为阳性。结果表明此法特异性和敏感性均很高，可做为猪传染性胸膜肺炎的快速诊断和流行病学调查的手段。     

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。     

猪传染性胸膜肺炎放线杆菌PCR检测试剂盒的研制

根据GenBank中猪传染性胸膜肺炎放线杆菌apxⅣA基因序列,设计了1对引物,通过对PCR反应条件进行优化,研制了检测猪传染性胸膜肺炎放线杆菌的PCR试剂盒。该试剂盒扩增的阳性条带为600 bp,特异性与敏感性结果显示,该PCR检测试剂盒的最低核酸检测量为50 CFU/mL,而对金黄色葡萄球菌、链球菌、多杀性巴氏杆菌、鼠伤寒沙门氏菌、副猪嗜血杆菌、大肠杆菌的扩增结果均为阴性。-20℃至少可保存12个月,且重复性良好。应用该PCR试剂盒对41份临床样本进行了检测,其PCR检测结果与细菌学检测结果相一致。结果表明,猪传染性胸膜肺炎放线杆菌PCR检测试剂盒能够对APP临床样品进行快捷、灵敏、准确的检测。     

猪胸膜肺炎放线杆菌PCR检测方法的建立

根据猪胸膜肺炎放线杆菌(APP)外膜脂蛋白基因序列，设计合成了1对特异性引物。经PCR扩增，APP1～10标准血清型菌株均能扩增出大小为980bp的DNA片段，而大肠埃希氏茵、猪多杀性巴氏杆菌、猪链球菌、猪肺炎霉形体和葡萄球菌等的扩增结果均为阴性。该方法检测APP DNA的敏感性可达2pg。表明，此PCR方法特异性好，敏感性高，可用于猪传染性胸膜肺炎的快速诊断。     

猪胸膜肺炎放线杆菌、肺炎支原体和多杀性巴氏杆菌联合检测芯片的研制及应用

本研究旨在建立联合检测胸膜肺炎放线杆菌、猪肺炎支原体和多杀性巴氏杆菌的DNA芯片.用7个从3种病菌基因组中扩增出的不同特异性靶DNA制作基因芯片,并对芯片的靶DNA和探针浓度、杂交温度、重复性、特异性和灵敏度进行了研究.结果表明,检测芯片的特异性强,能与测试的李氏放线杆菌、猪鼻支原体和副猪嗜血杆菌等9种病原区分;灵敏度高,在50μL标记反应体系中,能检测到10～50 pg基组DNA,芯片可重复利用.用芯片对44株目标菌的不同型标准菌株、分离株和疫苗株进行了检测.其信号值≥1 000,信号噪音比(SNR)≥6.用芯片对45头病猪和97头健康猪的临床样品选择培养物进行了检测,其检出率分别为多杀性巴氏杆菌71.1%和49.5%、胸膜肺炎放线杆菌42.2%和26.8%、猪肺炎支原体20%和22.7%,混合感染率分别为42.2%和24.7%.在检测临床样品时,芯片法与PCR的符合率为97.8%～100%,与分离鉴定法的符合率为87.6%～95.6%.研究表明,研制的芯片特异性强、敏感性高、可重复使用,是一种能有效用于胸膜肺炎放线杆菌、猪多杀性巴氏杆菌和猪肺炎支原体鉴定和联合检测的新工具.     

猪胸膜肺炎放线杆菌和副猪嗜血杆菌的鉴别诊断及血清型鉴定

利用PCR技术、琼脂扩散试验、糖发酵试验和间接血凝试验(IHA)对野外分离到的可疑猪胸膜肺炎放线杆菌和副猪嗜血杆菌进行了诊断和血清型鉴定.PCR鉴定分离物HS1580为副猪嗜血杆菌,分离物HS1582为猪胸膜肺炎放线杆菌;生化试验表明分离物HS1581和HS1582为猪胸膜肺炎放线杆菌;血清型鉴定分离物HS1580不属于被检的14个血清型之列,HS1581为App血清15型,HS1582为App血清7型.试验结果表明,综合使用PCR等技术可快速、准确地对这两种传染性细菌进行鉴别诊断和血清型鉴定.     

斑点杂交法检测猪传染性胸膜肺炎

将位于猪传染性胸膜肺炎放线杆菌(APP) apx A毒素基因 3′端的长为 442 bp的DNA片段作为模板制备出地高辛标记的 APP核酸探针。敏感性检测结果表明 ,该探针对 APPDNA的最低检出量为 1 .8ng。特异性检测结果表明 ,该探针能与 APP1～ 1 0血清型标准菌株 DNA抽提物发生特异性杂交反应 ,而与多杀性巴氏杆菌A型和 B型、链球菌、支气管败血波氏杆菌、肺炎双球菌、金黄色葡萄球菌、大肠杆菌 DNA进行的杂交反应均为阴性。应用该探针对临床 6份阳性病料 ,1 1份纤维渗出性病料进行检测 ,结果阳性病料全部检出 ;而对于 1 1份纤维渗出性病料 ,斑点杂交检出 4份是阳性 ,比 PCR方法 6/ 1 1的检出率要低 ,但仍表明所制备的探针用于 APP的检测是一种比较敏感、特异的诊断方法。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.