Assessment of superovulatory responses in terms of palpable corpora lutea and embryo recovery using plasma progesterone in yaks (Poephagus grunniens L.)

Plasma progesterone profiles were used to assess superovulatory responses in cyclic yaks (n=10) in terms of the number of ovulations and the number of embryos recovered. The animals were synchronized into oestrus following Ovsynch treatment. All the animals received a total of 200 mg Folltropin divided into morning and evening and spread over 4 days, beginning on day 10 of the oestrus cycle (day of expected oestrus=day 0). Plasma samples for progesterone estimation were collected daily starting from the day of expected synchronized oestrus to the day of flushing. All the animals were palpated per rectum on the day of flushing in order to record the number of corpora lutea. Of an estimated 27 ovulations from the nine yaks, only 16 embryos were recovered. Plasma progesterone profiles from individual yaks suggested that a poor superovulatory response in terms of embryo recovery in some animals was caused by the lysis of corpora lutea before flushing which was carried out 7 days after superovulatory oestrus. It was suggested that flushing 5 days post superovulatory oestrus could improve the superovulatory response in this species.     

川西北牦牛布鲁氏菌病血清流行病学调查

同时采用间接ELISA、虎红平板凝集试验和试管凝集试验三种血清学方法调查川西北牦牛布鲁氏菌病血清流行情况。对1070份采自川西北阿坝州8个草地县的牦牛血清样品经三种血清学方法检测,间接ELISA检测阳性率为25.4%（272/1070）,虎红平板凝集试验检测阳性率为12.7%（136/1070）,而试管凝集试验检测阳性率为9.1%（97/1070）。8个县均发现阳性布鲁氏菌病血清。与间接ELISA相比,虎红平板凝集试验的相对敏感性和特异性分别为50%和100%,而试管凝集试验的相对敏感性和特异性分别为35.7%和100%。布鲁氏菌病在川西北地区广泛存在,血清学方法是检测和监测布鲁氏菌病最常用和最简便的方法,其中间接ELISA方法最为敏感。     

Epidemiology,zoonotic aspects,vaccination and control/eradication of brucellosis in India

In India, brucellosis was first recognised in 1942 and is now endemic throughout the country. The disease is reported in cattle, buffalo, sheep, goats, pigs, dogs and humans. B. abortus biotype-1 in cattle and buffaloes and B. melitensis biotype-1 in sheep, goats and man are the predominant infective biotypes. The long-term serological studies have indicated that 5% of cattle and 3% of buffaloes are infected with brucellosis. Economic losses due to brucellosis in livestock are considerable in an agrarian country like India. There is no organised and effective brucellosis control programme in the country. With the indigenous development of serum and milk based ELISA kits, the population survey of the disease has been undertaken on a large scale in several states and plans for the control of the disease through calf-hood vaccination are being worked out. An innovative approach—Bovine Brucellosis Progressive Control Programme (BBPCP) is targeted to overcome the basic problems of ban on cow slaughter, distress sale of animals following the positive serological diagnosis of brucellosis and absence of a disease control strategy. The work plan for the implementation of BBPCP is presented.     

Evaluation of brucellosis RB51 vaccine for domestic water buffalo (Bubalus bubalis) in Trinidad

Thirty-two young domestic water buffalo (Bubalus bubalis) were obtained from a brucellosis-free farm to determine effectiveness of RB51 vaccination for prevention of Brucella infection under natural-exposure conditions in Trinidad. Study animals (20 males and 12 females 5–20 months old) were assigned to vaccination or control groups, using a block randomization design ensuring equal sex distributions between groups. The vaccination group received commercially available RB51 at the recommended calfhood dose of (1.0–3.4)×10¹⁰ colony-forming units (CFU) and controls received 2 ml sterile saline. Vaccination did not result in positive serologic results as measured by four traditional agglutination tests: standard tube agglutination test (STAT), standard plate agglutination test (SPAT), buffered plate agglutination test (BPAT), and card agglutination. Study animals were maintained in a brucellosis-positive herd in southern Trinidad with an estimated 56% prevalence to allow for natural exposure to B. abortus, which was evaluated using STAT, SPAT, BPAT, and card tests. Animals were sampled seven times over 2 years and were classified as positive if they had persistent agglutination titers or had Brucella isolated from specimens collected at completion of the study. Five of the original 32 study animals were lost to follow-up during the field trial. Six of the 14 (43%) vaccinated animals completing the study were classified as positive for Brucella infection—as were two of the 13 (15%) control animals (P=0.21). Isolates from four vaccinates and one control were confirmed as B. abortus biovar 1.     

Body status and blood metabolites profiles during resumption of postpartum ovarian activity in yak (Poephagus grunniens)

We examined the changes in body weight (BW), back-fat thickness (BFT) and blood metabolites in relation to postpartum (PP) ovarian activity status in twenty female yaks raised under semi-intensive system. BFT and ovarian activities, like follicle development, ovulation (OV) and corpus luteum (CL) development, were monitored from 4 to 15 weeks (wk) PP using ultrasonography. Resumption of ovarian activity was confirmed with ovulation of dominant follicle (DF) and subsequent CL development, and >1 ng/ml progesterone concentration in blood plasma sample after 1week of ovulation. Yaks were further classified as cyclic (with CL), acyclic (without CL), and cystic (with >25 mm follicular cyst; FC). Within 20 weeks PP, 60% yaks resumed cyclic ovarian activity, while 25% failed to initiate cycling activity, and 15% developed follicular cysts. In all categories of yak, BW gradually decreased (p < .05) till nadir; however, nadir reached earlier (p < .05) in acyclic yaks. BFT differed (p < .05) among the yak groups, but it tended to be higher in cyclic yaks as compared to acyclic and cystic. No difference (p > .05) in non-esterified fatty acids (NEFA) values was found among the different categories of yaks, whereas, beta-hydroxy butyrate (BHB) levels were higher in cystic animals as compared to acyclic and cyclic. Blood glucose levels decreased in all yaks during initial 2 weeks after calving. Our findings suggest that yaks with low BW, BFT and glucose levels, and higher BHB values were at risk of delayed resumption of ovarian activity and concomitant development of follicular cysts.     

流产布氏杆菌S19突变株构建及在小鼠感染模型中的免疫保护评估

通过构建标记疫苗株来解决流产布氏杆菌(B.abortus)鉴别诊断方面的缺陷,本研究以bp26基因作为重组靶住点,S19为亲本,利用bp26基因ORF外侧序列作为同源重组序列,卡那霉素抗性基因(Kanr)为抗性筛选标记,通过双交叉重组筛选获得bp26基因缺失突变的重组S19株,命名为S19-△26.小鼠感染结果表明,突变株S19-△26的残留毒力与亲本株S19相比较没有发生明显改变,康复时间约为15周,突变株S19-△26、亲本株S19和B.abortus强毒株S544接种小鼠后的第3周能检测出"O"抗原的特异性抗体,而第6周开始S19和S544接种小鼠BP26特异性抗体明显升高,S19-△26接种的小鼠一直没检测到BP26特异性抗体.小鼠免疫保护试验显示,脾脏分离CFU数比空白对照要低310g10,S544攻击后脾脏细菌分离数表明突变株具有与亲本疫苗株免疫保护性无明显差异.结果表明,S19-△26免疫能够通过血清学方法与野生型B.abortus感染后的免疫反应相区别,具备作为标记疫苗的潜力.     

农区牦牛、犏牛舍饲短期育肥效益分析

四川省是牦牛、犏牛生产大省,存栏量常年保持在高位,给草地生态环境造成巨大压力。但牦牛、犏牛养殖量的提升并未给牧民带来经济收入的增加,这与藏区冬春季恶劣的自然环境导致的营养缺乏密切相关。为解决这个问题,本试验将2.5~3.5岁的牦牛、犏牛运往四川省的农区(广汉)开展冬春季育肥研究,分析其带来的经济效益。通过120d的短期育肥,牦牛、犏牛分别增重64.00kg和85.80kg,增收645元/头和1299元/头。试验结果表明,牦牛、犏牛可以通过在农区进行冬春季育肥达到增收的目的。     

西藏地区牦牛瘤胃中兼性厌氧纤维素降解菌的分离鉴定

本研究旨在从西藏地区牦牛瘤胃中分离出具有分解纤维素能力的兼性厌氧菌,为青贮饲料微生物添加剂的研制提供支持。试验采集了西藏那曲地区成年牦牛的新鲜瘤胃液,经刚果红染色初筛,滤纸降解复筛,获得分解纤维素能力强的菌株,对菌株生长速率及酶活力进行测定,经形态学、生理生化特性和16S rRNA序列分析对菌株进行鉴定,并分析了菌株对水稻秸秆的降解效果。试验分离出一株兼性厌氧纤维素降解菌,属于肠球菌属,即粪肠球菌(Enterococcus faecalis) JF85。菌株JF85在15~55 ℃,pH 3.0~7.0及3.0%和6.5% NaCl培养基中生长良好。接种JF85,36 h后可获得最大内切葡聚糖酶活力(0.41 U/mL)和滤纸酶活力(0.13 U/mL)。在模拟发酵试验中,接种菌株JF85,14 d后水稻秸秆干物质、纤维素和半纤维素含量与对照组相比显著降低(P<0.05);在发酵第7天,JF85处理组显示最高的可溶性碳水化合物含量,整个发酵过程中木质素含量变化不显著(P>0.05)。菌株JF85具有分解纤维素、耐酸、耐盐特性,在青贮饲料生产中具有较好的应用前景。     

Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations

AIMS: To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.

METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was?>30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.

RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.

CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.     

Quantification of water buffalo (Bubalus bubalis) cytokine expression in response to inactivated foot-and-mouth disease (FMD) vaccine

This study describes the quantification of cytokine expression of vaccinated water buffaloes with FMD inactivated vaccine. Using real-time PCR quantification assay, expression of Th1 (IL-2, IL-12p40, IFNγ); Th2 (IL-4, IL-10) and inflammatory (IL-6, TNFα) cytokines were quantified weekly for the entire three-week duration of the experiment. It was noted that IFNγ, IL-10 and TNFα had peaked on week three post-vaccination while the remaining cytokines peaked on the second week and decreased by the third week. The counteraction between IFNγ and IL-4 was noted as well as the possible suppressive action of IL-10 to that of IL-2 and IL-12, which is a common phenomenon between Th1 and Th2 cytokines. Synergy between TNFa and IL-6 was also observed. These findings suggest that within the immune system of water buffalo there is a dynamic cell-mediated and humoral interaction in response to immunogen. This assessment of the cytokine expressions is vital for the study of water buffalo disease progression and concurring protective immune responses.     

Assessment of serological response of young and adult sheep to conjunctival vaccination with Rev-1 vaccine by fluorescence polarization assay (FPA) and other serological tests for B. melitensis

The serological response of young and adult sheep vaccinated conjunctivally with Rev-1 vaccine was assessed by fluorescence polarization assay (FPA), Rose Bengal test (RBT), complement fixation test (CFT), modified Rose Bengal test (m-RBT), indirect ELISA (i-ELISA) and competitive ELISA (c-ELISA), at different post vaccination intervals. One hundred and thirty six adult sheep and 64 lambs were used in the study. The vaccinated animals were bled prior to vaccination (0 day) and thereafter at 21st, 42nd, 35th, 63rd, 91st, 125th, 159th, and 223rd and 330th day post vaccination. The majority of animals (young and adult) showed positive reaction by FPA, RBT, CFT, m-RBT and c-ELISA 21 days post vaccination, whereas by i-ELISA at 42 days. All tests perform equal when animals vaccinated as young are tested 125 days (4 months) post vaccination. In case of animals vaccinated at adulthood, FPA, RBT, CFT and c-ELISA perform equal if the animals are tested 223 days (approximately 8 months) post vaccination. I-ELISA and m-RBT show low specificity if ewes vaccinated at adulthood are tested 330 days (11 months) post vaccination. If control of brucellosis in sheep is based on conjunctivally vaccination of lambs with Rev-1, the vaccinated animals can be tested by any test used for diagnosis of B.melitensis infection accurately at least 4 months post vaccination. If brucellosis control is based on mass vaccination the use of m-RBT and i-ELISA is not recommended for testing adult animals at least for 330 days (11 months) post vaccination due to tests low specificity. Further research is needed so the appropriate cut-offs to be established for FPA, c-ELISA or i-ELISA to become valuable tools for the eradication of Brucella spp. infection in small ruminants in areas where vaccination is practiced.     

应用高效体积排阻色谱法测定市场抽检口蹄疫灭活疫苗中的抗原（146S）含量

应用高效体积排阻色谱法对5批市场抽检口蹄疫灭活疫苗中有效抗原(146S)含量进行检测,并使用口蹄疫O型、A型和亚洲1型抗原测试卡对5批疫苗中的抗原进行鉴别。结果显示高效体积排阻色谱法测定146S标准品浓度与峰面积线性关系良好,5批疫苗均检测到146S特征吸收峰(R2=0.9937,n=7),经计算得到灭活疫苗中有效抗原含量分别为2.05、3.73、2.03、4.87、3.41μg/m L;使用抗原测试卡鉴别了5批疫苗中的抗原类型。结果表明,高效体积排阻色谱法简便、高效,准确度较高,有望在口蹄疫灭活疫苗的质量控制中发挥重要作用。     

Seroprevalence and risk factors associated with exposure of water buffalo (Bubalus bubalis) to Neospora caninum in northeast Thailand

Water buffalo are important draft animals for agriculture in resource-restricted areas worldwide. Water buffalo were shown to be experimentally susceptible to infection with Neospora caninum, potentially affected by neosporosis, and naturally exposed to the parasite in Asia. Although enzootic to Thailand, the distribution of N. caninum among Thai water buffalo is unclear. The objectives of this study were to determine the seroprevalence of N. caninum among water buffalo of northeast Thailand and to identify risk factors associated with their exposure to N. caninum. Sera from 628 water buffalo from 288 farms were tested with an indirect fluorescent antibody test (IFAT). A total of 57 samples from 48 herds contained antibodies to N. caninum, indicating overall seroprevalence of 9.1% and 16.7% among individual animals and herds, respectively. The overall seroprevalence was highest in provinces located in the Khorat Basin in the southern part of the region tested. Host age was also associated with seroprevalence, with the greatest seroprevalence (16.1%) among buffalo over 10 years of age, followed by 5–10 years of age (13.4%), 3–5 years (9.2%), and less than 3 years (1.2%). These results collectively suggested that horizontal transmission from canine definitive hosts was an important route of water buffalo exposure to N. caninum. These results also verified the importance of risk factor analysis for effective bovine neosporosis control strategies at the local level.     

Seroprevalence to bovine virus diarrhoea virus and other viruses of the bovine respiratory complex in Venezuela (Apure State)

Six hundred and fifteen serum samples obtained from cows in five districts of Apure State, Venezuela, were tested by ELISA for antibodies to bovine virus diarrhoea virus (BVDV). The same samples were also ELISA-tested for antibodies to bovine herpesvirus type 1 (BHV-1) and bovine respiratory syncytial virus (BRSV). Additionally, the haemagglutination-inhibition (HI) test was used for detecting antibodies to parainfluenza virus type 3 (PIV-3). Overall, seroprevalence to BVDV was 36±7% (SE); seroprevalence varied by district (19–42%). BHV-1 seroprevalence was 67±4%; variation by district was similar to that of BVDV. However, the first 80 serum samples tested by BHV-1 ELISA all had a strong background reaction with the control antigen. Therefore, these sera were adsorbed to a homogenate of non-infected bovine kidney cell line (MDBK) and re-tested by ELISA. The non-specific reactivity was significantly reduced (p < 0.001 by Wilcoxon's signed-rank test). Compared to the virus-neutralisation (VN) test, the adsorbed BHV-1 ELISA showed 94% agreement and gave a κ value of 0.84, indicating that the adsorption did not interfere with test accuracy. Seroprevalence against BRSV was 85±3%, and showed differences across districts. Most of the cows (94±2%) were seropositive to PIV-3, and there were no significant differences among districts.     

Abortion due to Salmonella enterica serovar Abortusovis (S. Abortusovis) in ewes is associated to a lack of production of IFN-gamma and can be prevented by immunization with inactivated S. Abortusovis vaccine

Salmonellosis due to Salmonella enterica serovar Abortusovis (S. Abortusovis) is mainly characterized by abortion in sheep. Little is known about the immune response, which develops in the host as a result of infection. We evaluated the immune response of pregnant ewes vaccinated and successively exposed to full virulent S. Abortusovis. We found that vaccine constituted by inactivated S. Abortusovis induced both humoral and cellular-mediated immune response and that it provided protection against a challenge infection due to a fully virulent S. Abortusovis. Furthermore, we found an association between the lack of capability to produce IFN-gamma and abortion. This evidence suggests that protection against abortion can be associated to an IFN-gamma mediated mechanism. Our findings represent an interesting insight to better understand the interplay between host and S. Abortusovis and the effector mechanisms underpinning immune-based protection.     

Development of a genotyping tool for a functionally relevant CYP2C19 allele (Phe100Asn,Ala103Val and Ile112Leu) in cynomolgus macaques

In cynomolgus macaques, which are widely used in drug metabolism studies, CYP2C19(formerly known as CYP2C75) is abundantly expressed in liver, metabolizes human CYP2Csubstrates and is thus an important drug-metabolizing enzyme. One of the cynomolgusCYP2C19 alleles (p.Phe100Asn, p.Ala103Val and p.Ile112Leu) results insubstantially reduced metabolic activity and thus is an important allele in drugmetabolism studies. For this allele, a genotyping tool was developed using allele-specificTaqMan probe. Genotyping 40 Cambodian cynomolgus macaques using this tool found 1homozygote, 17 heterozygotes and 22 wild type animals, and the result was confirmed bydirect-sequencing. Interestingly, this allele frequency was similar to that of Chinesecynomolgus macaques. The genotyping tool established is useful for drug metabolism studiesusing cynomolgus macaques.     

Assessment of enzyme linked immunosorbent assay based diagnostic kits (Toxokit-G and Toxokit-M) for the detection of IgG and IgM antibodies to Toxoplasma gondii in human serum

An enzyme linked immunosorbent assay (ELISA) using penicillinase was developed in the form of diagnostic kits (Toxokit-G and Toxokit-M) for the detection of IgG and IgM antibodies to Toxoplasma gondii. The performance of both the kits was compared with commercially available diagnostic kits, i.e. Enzygnost-Toxoplasmosis/IgG (Behring Co., Germany), TOXOTEK-G (Flow Lab., U.K.) and Toxoplasma IgM Microassay (Diamedix Corp., U.S.A.) by testing toxoplasma-suspected human serum samples. The results indicate a good reliability between these diagnostic kits. Toxokit-G has 86.66 and 96.05% sensitivity and specificity respectively. The main advantage of Toxokit-G is that the end result can be assessed visually without using sophisticated instruments. Toxokit-M has 100% sensitivity and specificity and test results were not affected by the presence of antitoxoplasma IgG antibodies, rheumatoid factor or antinuclear antibodies.