重庆三峡库区肉牛结核病布鲁菌病的调查

采用牛提纯结核菌素皮内变态反应结合γ-干扰素试验、虎红平板凝集试验、试管凝结试验及ELISA法分别对重庆三峡库区肉牛结核病、布鲁菌病进行了抽样检测。结果显示,该区域肉牛结核病阳性检出率为1.2%,布鲁菌病阳性检出率为1.04%。其中,库区东北部区县肉牛结核病、布鲁菌病的阳性检出率均为最高,分别为1.83%、1.14%;3种肉牛养殖规模条件下,个体散养农户牛群结核病、布鲁菌病的阳性检出率均为最高,分别为2.21%、2.94%;所调查的3个年龄段牛群中,19月龄以上牛群结核病、布鲁菌病的阳性检出率最高,分别为2.91%、4.85%。     

奶牛布鲁菌病的血清学检测

为了解奶牛布鲁菌病的流行情况,采用虎红平板凝集试验和试管凝集试验随机对规模养殖场、中小规模养殖场及散养户共1 000头奶牛进行布鲁菌病初检和确诊.结果表明,被检奶牛血清16份呈布鲁菌阳性,阳性率为1.6%,其中散养户、中小规模养殖场和规模养殖场饲养奶牛血清阳性数分别为6份、5份、5份,阳性率分别为2.67%、1.52%...     

奶牛布鲁菌病的检测试验

试验对内蒙古包头市部分地区出现较多流产、早产、死胎、胎盘滞留等疑似布鲁菌病患牛的奶牛养殖小区、个体养殖户的608头奶牛用虎红平板凝集试验、试管凝集试验进行了布鲁菌病血清学检测。结果虎红平板凝集试验检测平均阳性率为27.96%,试管凝集试验平均阳性率为25.82%,表明所检测地区奶牛布鲁菌病的感染率较高。     

虎红平板凝集试验与试管凝集试验检测奶牛布鲁菌病的比较

布鲁菌病主要采用凝集试验来检测,本试验用虎红平板凝集试验和试管凝集试验对江苏海安、江都、无锡和兴化地区的660头奶牛的血清样品进行平行检测,虎红平板凝集试验的阳性检出率为9.7%,试验管凝集试验的阳性检出率为5.5%;与后者相比,虎红平板凝集试验的敏感性为100%,特异性为95.3%,符合率为95.6%。这些数据表明,江苏地区某些奶牛场存在布鲁菌感染,虎红平板凝集试验可以用于布鲁菌病初步检测。     

奶牛布鲁菌病的检测试验

试验对内蒙古包头市部分地区出现较多流产、早产、死胎、胎盘滞留等疑似布鲁菌病患牛的奶牛养殖小区、个体养殖户的608头奶牛用虎红平板凝集试验、试管凝集试验进行了布鲁菌病血清学检测.结果虎红平板凝集试验检测平均阳性率为27.96%,试管凝集试验平均阳性率为25.82%,表明所检测地区奶牛布鲁菌病的感染率较高.     

奶牛布鲁菌病血清学调查及病原分离鉴定

2015—2016年应用虎红平板凝集试验、试管凝集试验对新疆维吾尔自治区巴音郭楞蒙古自治州21个奶牛场、503个奶牛养殖户所饲养的奶牛进行了布鲁菌病血清学调查,虎红平板凝集试验阳性率为1.10%,试管凝集试验阳性率为0.82%。对2013—2016年4年内在该地区收集的奶牛流产胎儿、胎衣、阴道分泌物等243份病料进行布鲁菌的分离鉴定,结果分离出2株羊种2型布鲁菌和2株牛种3型布鲁菌。血清学调查及布鲁菌分离鉴定结果佐证了在该地区存在布鲁菌病,建议奶牛养殖场（户）和有关部门切实做好布鲁菌病的检疫及防控工作。     

张家口市规模化奶牛场布鲁菌病血清学检测与分析

本试验于2012年3～5月份,对张家口市规模化奶牛场未经布鲁菌病苗免疫的2 680头奶牛进行了布鲁菌病血清学检测与分析。结果显示,虎红平板凝集试验检测的阳性率为0.25%,试管凝集试验检测的阳性率为0.45%。数据表明,布鲁菌病已在张家口市规模化奶牛场中零星出现,相关部门需引起高度重视,做好布病防控工作。     

榆林市某县奶牛结核病和布鲁菌病检测与分析

为了解榆林市某县2010年-2014年期间奶牛结核病和布鲁菌病的发生情况,应用结核病国家检测标准(GB/T18645-2002)-结核菌素皮内变态反应检测奶牛结核病,应用虎红平板凝集试验和试管凝集试验检测奶牛布鲁菌病。结果表明,奶牛结核病平均阳性率为0.72%;奶牛布鲁菌病平均阳性率为1.19%,虎红平板凝集试验和试管凝集试验2种检测方法的符合率一致。     

江西省萍乡市某羊场布鲁菌病的流行病学分析

江西省萍乡市某山羊场妊娠母羊散发流产,为了分析该羊场流产的发生是否与布鲁菌感染有关,同时掌握该羊场布鲁菌病的流行情况,随机抽样采血共分离得到100份山羊血清,首先使用虎红平板凝集试验进行初步鉴定,然后通过试管凝集试验重新检测阳性血清。结果表明,该羊场布鲁菌病阳性率为20％。由此可以得出,该羊场的布鲁菌病防控工作存在较严重的问题,应制定有效的防治措施,将山羊布鲁菌病的检测纳入日常疾病监测工作中,最终达到净化该病的目的。     

牛、羊布鲁菌多重PCR方法的建立与应用

根据布鲁菌属特异性基因BCSP31和布鲁菌种间特异性标志IS711插入序列,设计合成了3对引物,以牛种布鲁菌544A、104M和羊种布鲁菌16M基因组DNA为模板,通过优化反应条件,建立了可同时检测布鲁菌属、牛种布鲁菌和羊种布鲁菌的多重PCR方法。牛种布鲁菌可扩增出301和114 bp 2条带,羊种布鲁菌可扩增出301和253 bp 2条带,该方法对牛种布鲁菌544A和羊种布鲁菌16M混合DNA模板的最小检出量为100 pg,对大肠杆菌O157∶H7、小肠结肠炎耶尔森菌等15种参照菌的核酸扩增结果均为阴性。应用该方法对吉林省某牛场的106份粪便进行检测,虎红平板凝集试验作对照,结果PCR检测9份为阳性,且全为牛种布鲁菌阳性,对应的虎红平板凝集试验也为阳性。结果表明,建立的多重PCR方法具有良好的敏感性和特异性,为布鲁菌病的鉴别诊断提供了一种分子检测工具。     

Prevalence of Neospora antibodies in beef cattle in New Zealand

AIM: To estimate the prevalence of Neospora infection in a sample of New Zealand beef cattle. METHODS: The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island . Sera were tested using an ELISA against Neospora tachyzoite antigen. RESULTS: The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers. CONCLUSION: Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.     

Bovine brucellosis serum agglutination test prevalence and breed disposition according to prevalent management systems in the Lake Victoria zone of Tanzania

A total of 13078 cattle 8 months of age and older belonging to 558 units in the Lake Victoria zone of Tanzania were screened for brucellosis using the serum agglutination test (SAT). This exercise was executed as a Tanzanian Agriculture Ministry's directive for screening all adult bovines in the country reared under controlled grazing and receiving good veterinary supervision and inputs so that brucellosis control measures could be instituted. In this category two types of management systems were encountered: Dairy, comprising 15 units totalling 3626 Exotic (Friesian and Ayrshire) and Grade (Zebu and Exotic) crosses, and Ranch, comprising two units totalling 6756 mainly dual-purpose Mpwapwa (MPW) animals. These three animal types have much higher milk production potential than the indigenous Tanganyika shorthorn Zebu (TSZ). This latter beef type is reared under local management system and owned wholly by subsistence stock owners practising uncontrolled communal grazing and having little or no veterinary supervision and inputs. However, TSZ animals from 541 farm units totalling 2705 members were also screened from the east and south sub-zones because of their close proximity to the Dairy/Ranch units and also the Serengeti Wildlife National Park. This exercise revealed an overall prevalence rate of 10.8%. There was moreover a significant difference in the seroprevalence rates among the management systems (P < 0.001). The lowest prevalence rate (4.3%) was found in the Local management system, with Dairy intermediate (6.3%) and Ranch highest (15.8%). There was also significant variation in prevalence rates between TSZ and Grade animals, and between MPW and Exotic animals (P < 0.001).     

The use of skin delayed-type hypersensitivity as an adjunct test to diagnose brucellosis in cattle: a review

Brucellosis, caused by bacteria of the genus Brucella, is a contagious disease that causes economic loss to owners of domestic animals due to loss of progeny and milk yield. Because cattle, sheep, goats, and to a lesser extent pigs are considered to be the source of human brucellosis, serological tests have been used to screen domestic animals for antibodies against Brucella. Although the serological tests helped to eradicate brucellosis in many countries, serological tests are not always adequate to detect latent carriers of Brucella. Therefore, the use of the skin delayed-type hypersensitivity (SDTH) test, which is independent of circulating antibodies, might improve the diagnosis of brucellosis. In the literature, however, there are conflicting reports as to the value of the SDTH test for the diagnosis of brucellosis. Some studies consider the test unreliable, whereas others advocate its use because it detects brucellosis earlier than serological tests. The objectives of this study were therefore to assess the characteristics of the SDTH test, to select a Brucella strain that will yield a suitable brucellin for use in the field, and to determine whether the use of serological tests in combination with the SDTH test improves the detection of brucellosis. The results of this study clearly show that the SDTH test detects latent carriers of Brucella and confirms brucellosis in cattle with ambiguous serological test results. Brucellins prepared from smooth or mucoid strains of Brucella are better suited for use in the field than brucellins prepared from rough strains because they detect brucellosis in cattle with acute as well as chronic infection. The SDTH test is highly specific (99.3% specificity), and repeated testing of naive cattle or cattle infected with microorganisms that serologically cross-react with Brucella does not sensitize cattle to subsequent SDTH tests. However, it is possible that some naive cattle may serologically react to the injection of brucellin. The effect of these serological reactions on the sero-diagnosis of brucellosis is limited, because cattle may only now and then react serologically either with the serum agglutination test (SAT) or the complement fixation test (CFT). Nevertheless, cattle infected with microorganisms that serologically cross-react with Brucella may test seropositive for brucellosis 4 to 7 weeks after injection of brucellin, depending on the cross-reacting microorganism. The value of the SDTH test for the diagnosis of brucellosis was demonstrated after an outbreak of brucellosis. When the SDTH test was used in combination with SAT and CFT at diagnostic threshold > or =2 mm or > or =1 mm (increase in skinfold thickness), respectively, 39/44 (88%) or 42/44 (95%) of the infected cattle were detected compared with only 27/44 (61%) when SAT and CFT were used. When cattle in areas of low prevalence or in areas free from brucellosis are tested with the SDTH test an increase > or =2 mm in skinfold thickness should be considered indicative of infection. When the control and eradication of brucellosis is based on test-and-slaughter, an increase of > or =1 mm in skinfold thickness should be considered indicative of infection. Repeated serological testing complemented with the SDTH test in this programme will shorten the quarantine (movement control) period of a suspect herd, limiting the financial loss incurred during outbreaks of the disease. Consequently, since the SDTH test usually does not interfere with the serological diagnosis and can safely be used to establish the infection status of cattle in a suspect herd, it is opportune to consider adding the SDTH test to the procedure currently used to diagnose brucellosis in individual animals.     

Prevalence of Neospora antibodies in beef cattle in New Zealand

dAim:To estimate the prevalence of Neospora infection in a sample of New Zealand beef cattle.

dMethods: The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island. Sera were tested using an ELISA against Neospora tachyzoite antigen.

dResults: The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers.

dConclusion: Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.     

Brucellosis in Argentina

Brucellosis has been recognized in Argentina since the 19th century. Several studies demonstrated the presence of the disease in most of the domestic species. Actually, the estimate of prevalence is that between 10 and 13% of the farm animals are infected with bovine brucellosis with an individual rate of 4–5%. The annual economical losses have been estimated at US$ 60,000,000. The control of bovine brucellosis began in 1932 and successive resolutions have been issued since then. The current resolution indicates that B. abortus S19 is mandatory in female calves between 3 and 8 months of age. The vaccine strain B. abortus RB51 was provisionally approved but only for cattle older than 10 months of age. The brucellosis control program consists principally of test and slaughter. This methodology has been successful mainly in the dairy farms that have the incentive due to increased pricing because of obtaining a low prevalence of the disease. Brucellosis has been found in porcine, caprine, ovine and canine species. All Brucella species have been found in the country. Human brucellosis is an important disease and a national coordinated diagnostic net has been formed to better control the disease in man.     

A mixed methods study of ruminant brucellosis in central-eastern Tunisia

In this study, we conducted an investigation to determine the true prevalence of bovine and ovine brucellosis in central-eastern Tunisia. A total of 1134 veterinary samples taken from 130 ruminant herds were screened for brucellosis using IS711-based real-time PCR assay. Sera collected from the ruminants were tested using the Rose Bengal test and indirect enzyme-linked immunosorbent assay. Based on serological and molecular results, the true adjusted animal population level prevalence was 23.5 % in cattle, against 13.5 % in sheep. In addition, the true adjusted herd level prevalence of brucellosis was 55.6 % in cattle and 21.8 % in sheep. A statistically significant association was found between vaginal and milk shedding for ruminants. In addition, our results showed that Brucella abortus could be responsible for bovine and ovine brucellosis. Multivariable logistic regression analysis at the animal population level indicated that age and origin variables were important risk factors for cattle. However, age and abortion variables were found to be associated with ovine brucellosis. At the herd level, risk factors for Brucella positivity were as follows: abortion and herd composition for cattle against herd composition, mortality rates, and hygiene for sheep. Animal hygiene, food quality, and sanitary practices on the farm should be applied as strategies to control brucellosis in herds.     

肉牛布鲁氏杆菌病防控现状及措施

布鲁氏菌病是由布鲁氏菌引起的一种急性或慢人畜共患传染病,该病除了导致养牛企业直接经济损失外,还可能发生严重食品安全问题和因人被感染导致的严重公共卫生安全问题。多年来,各级动物防疫部门主要关注奶牛的布病防控,对肉牛的布病防控介入很少,造成肉牛布病感染情况不明、底子不清,防控力度不够。随着规模化肉牛养殖业的不断兴起,肉牛布鲁氏菌病防控可不容缓。因此,必须采取综合措施有效防控肉牛布鲁氏菌病。     

γ-干扰素ELISA法检测江西省宜春市肉牛场结核病流行情况

江西省宜春市肉牛规模化养殖场发展迅速,肉牛结核病一旦蔓延将造成巨大经济损失。为掌握宜春市某规模化肉牛养殖场结核病的感染情况,采用γ-干扰素ELISA检测方法对该养殖场的300余头肉牛进行随机抽检。结果表明,随机抽取的30头肉牛样品的阳性检出率为3.33%。其中,所调查的2个年龄段的肉牛群中,以12月龄以上的肉牛群阳性检出率最高,为6.67%。在春、夏两季节调查的牛群中,春季阳性检出率最高,为6.67%。数据表明,该牛场结核病的免疫效果较差,须加强防控措施。     

宁夏固原市肉牛口蹄疫和布鲁氏菌病血清抗体检测与分析

[目的] 为了调查宁夏固原市肉牛口蹄疫和布鲁氏菌病的流行情况,[方法]通过采集74份不同月龄肉牛血清样本,采用酶联免疫吸附试验(ELISA)对2种疫病抗体进行检测和分析。[结果],抗体阳性率由高到低分别为A型口蹄疫(48.65%)、O型口蹄疫(43.24%)、布鲁氏菌病(12.16%)。混合抗体阳性率中主要以O型和A型口蹄疫混合抗体阳性率最高(58.54%)。O型口蹄疫在西吉县的阳性检出率最高(88.24%),彭阳县最低(6.67%);A型口蹄疫在西吉县阳性检出率最高(82.35%),彭阳县最低(26.67%);布鲁氏菌病在原州区阳性检出率最高(15.00%),泾源县和彭阳县未检出。从不同年龄来看,3种疫病均在＞12月龄的肉牛中阳性率最高,分别为O型口蹄疫69.23%、A型口蹄疫76.92%、布鲁氏菌病15.38%。[结论] 固原市各个县区肉牛养殖地区均出现2种病原感染的情况,以O型和A型口蹄疫混合感染为主。在肉母牛养殖过程中,应加强对以上病原的检疫并采取相应的防控措施。     

Prevalence of serum antibodies to Mycobacterium avium subsp. paratuberculosis in cattle in Galicia (northwest Spain)

Prior to establishing a control and prevention program for Johne's disease in cattle in Galicia (northwest Spain), a survey was conducted to estimate the prevalence of the disease. For this survey, 61,069 animals of at least 1-year of age from 2735 randomly selected herds were bled and samples analyzed with a commercial ELISA. The estimated true individual-level prevalences – assuming the manufacturer's reported test sensitivity of 48.5% and specificity of 98.9% – were 3.02% in dairy cattle, 1.03% in beef cattle and 2.83% in animals from farms with both dairy and beef cattle. True herd prevalences (with herds declared positive if one or more animals tested positive) were 10.69% for dairy herds, 0% for beef herds and 2.71% for mixed herds. When herds were declared positive if at least two animals tested positive, true herd prevalences were 14.75% for dairy herds, 1.47% for beef herds and 12.01% for mixed herds. Assuming a higher specificity of 99.4%, true individual-level prevalences increased to 4.03% in dairy herds, 2.07% in beef herds and 3.84% in mixed herds. Herd prevalences were 27.77%/18.79%, 2.78%/2.40% and 5.70%/12.24% (using the one/two-animal cut-offs) in dairy, beef and mixed herds, respectively. In conclusion, these results seem to indicate that a small percentage of cows and a rather high percentage of dairy herds in this region are MAP-seropositive.