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1.
Infectious coryza is an acute respiratory disease caused by infection with Avibacterium (Haemophilus) paragallinarum. It is characterized by nasal discharge and facial swelling and is associated with growth retardation and a reduction in egg production. Hemagglutination inhibition (HI) tests are used to estimate vaccine-induced immunity against infectious coryza in vitro; however, these procedures are complicated and their sensitivity is insufficient. To address these problems, an enzyme-linked immunosorbent assay (ELISA) technique using serovar-specific regions of HMTp210 (210 kDa), an outer-membrane protein of A. paragallinarum, was developed to measure the antibodies against infectious coryza. Chickens with an ELISA titer of 0.3 or more did not exhibit clinical signs of infectious coryza against challenge with A. paragallinarum, although their HI antibody titers were negative. On the other hand, chickens with an ELISA titer below 0.3 exhibited clinical signs of the disease with one exception. Antibody prevalence rates on ELISA were 80% and 60% against infection with serovars A and C, respectively, and ELISA also detected antibodies in chickens infected with A. paragallinarum with a sensitivity higher than that of HI tests. Taken together, the ELISA technique developed in this study is a valuable tool for the measurement of antibodies produced against the infectious coryza vaccine or in response to an infection with A. paragallinarum.  相似文献   

2.
血凝素是副鸡嗜血杆菌(Haemophilus paragallinarum,Hpg)的主要抗原成分之一,鸡只对Hpg的免疫力与血凝素抗体滴度成正相关。根据GenBank上已发表的B型Hpg Dalian株的血凝素基因序列(AY622378),设计合成了1对特异扩增Hpg血凝素基因的引物。以大连分离株Hpg中提取的细菌DNA为模板,利用PCR扩增出了1038bp的血凝素基因,将其克隆到pET-32a载体上,构建了pET-HA原核表达质粒并在BL21。大肠杆菌中过量表达。血凝试验显示纯化的重组蛋白具有血凝活性;Western试验证明该重组蛋白可以被B型Hpg特异性鸡血清所识别。本研究在国内首次对Hpg的血凝素基因进行克隆表达,并分析了重组蛋白的血凝活性。  相似文献   

3.
The genomic DNA of Haemophilus paragallinarum (Hpg) serotype A strain 221 was cloned into vector plasmid pBR322. The recombinant plasmids were introduced into Escherichia coli (E. coli) strain C600. Subsequently, a total of 277 transformants were obtained. One, designated strain no. 6, expressed hemagglutination activity against chicken erythrocytes. Strain no. 6 contained the recombinant plasmid pNV102, and DNA of about 2.57 kb was inserted into pNV102. When strain no. 6 was cured of pNV102, the strain lost hemagglutination activity. When the cured strain was retransformed with pNV102, hemagglutination activity was restored. E. coli strain no. 6 reacted with monoclonal antibody specific to the hemagglutinin of Hpg serotype A in a dot-blotting analysis. Chickens immunized with the inactivated strain no. 6 produced the hemagglutination inhibition (HI) antibody, and chickens possessing the HI antibody showed protection against challenge exposure by Hpg strain 221.  相似文献   

4.
The relationship between the antigen release from formulations in vitro and the antibody response after administration of water-in-oil-in-water (W/O/W) emulsion vaccines containing Haemophilus paragallinarum (Hpg) was studied in chickens. Increases of sorbitan sesquioleate volume in the formulation led to slower antigen release and tended to induce higher hemagglutination-inhibition (HI) antibody titers. In addition, the vaccines prepared with internal aqueous phase:oil phase:external aqueous phase (A:O:A) ratios of 3:4:3 and 3:3:4 also showed slower release of antigen and higher HI antibody titer compared with those of an A:O:A ratio of 3:2:5. Vaccines prepared with polyoxyethylene (POE)(10) hydrogenated castor oil or POE(40) hydrogenated castor oil instead of sorbitan sesquioleate showed higher release and lower antibody HI titers. As a result, HI antibody titers at 6 wk after vaccination were inversely related to antigen release, as determined by the release test. The correlation coefficient was 0.942. In infectious coryza W/O/W emulsion vaccines, the slow release of antigen from the formulation induced and maintained high HI antibody titers of Hpg.  相似文献   

5.
The serological response of chickens either vaccinated or artificially infected with Haemophilus paragallinarum (Hpg) serovar A or C was investigated using both a specific hemagglutinin (HA) antigen and a common HA antigen. With Hpg serovar A, both vaccinated and artificially infected chickens produced hemagglutination-inhibition (HI) antibodies to Hpg serovar-specific and Hpg common HA antigens. Most chickens vaccinated with Hpg serovar C had detectable HI antibodies to both types of HA antigen by 3 weeks postvaccination, after which titers gradually declined. In contrast, most chickens artificially infected with serovar C produced HI antibodies to only the common HA antigen; very few of these chickens produced HI antibodies to the serovar-specific HA antigen.  相似文献   

6.
应用3批鸡传染性鼻炎二价油乳剂灭活疫苗进行了保存期检验,结果表明,二价苗在4-8℃保存12个月和18个月后免疫鸡群,鸡群对A、C型强致病力菌株的保护率在二免后4周左右分别为100%和88.5%,血清SPA、阻断ELISA和HI抗体阳性检出率较高,但疫苗保存18个月后所免疫鸡的血清C型HI抗体效价的几何平均数有显著的下降。因此,该二价苗的保存期以12个月为宜。  相似文献   

7.
从不同地区免疫失败鸡场的鸡传染性鼻炎疑似鸡体内共分离到19株细菌,经回归试验、PCR等方法鉴定为副鸡嗜血杆菌。又将分离株用血清平板凝集试验、血凝抑制试验和型特异性单抗进行了血清型的鉴定,结果表明分离菌有15株为A型,4株为B型,说明我国鸡传染性鼻炎的流行已经出现了新的特点,在疾病预防和控制中应加以注意。另外大多数鸡场的免疫失败是由于免疫效果不良所致,但也有相当一部分鸡场的免疫失败是由于B血清型的出现引起的。  相似文献   

8.
Investigations were conducted to determine the occurrence of Avibacterium paragallinarum in poultry in Uganda. A total of 710 each of bacteriologic and serum samples were taken from chickens and turkeys for demonstration of A. paragallinarum and antibodies. Samples for isolation of A. paragallinarum were also subjected to direct polymerase chain reaction (PCR) for demonstration of the organism's presence. Antibodies to A. paragallinarum were demonstrated in the sera using the hemagglutination inhibition test. A total of five isolates were recovered from two out of five commercial layer chicken farms investigated where suspected cases of infectious coryza were reported, and all of them belonged to Page's serovar C. PCR detected more positive samples (11/68) than did culture (5/68). Isolates were not recovered from free-range poultry nor were there any positive samples by PCR. The overall seroprevalence was 40.5% and the seroprevalence to serovars A, B, and C were 18%, 0.5%, and 22%, respectively. Antibodies to all Page's serovars A, B, and C were demonstrated in free-range chickens but only serovar C antibodies were demonstrated in commercial chickens. No antibodies were demonstrated in turkeys. This is the first time infectious coryza has been confirmed in Uganda and the causative agent, A. paragallinarum, isolated. A high seroprevalence observed in free-range chickens seems to indicate a subclinical infection under extensive village management conditions.  相似文献   

9.
OBJECTIVE: To characterise 18 isolates of Haemophilus paragallinarum isolated from chickens in Indonesia. PROCEDURE: The isolates were identified to species level by traditional phenotypic methods. Six of the isolates were also identified by a species-specific polymerase chain reaction. Fourteen of the isolates were examined for resistance to a panel of seven antimicrobial agents using a disc diffusion method. All 18 isolates were serotyped according to the Page scheme using reference antisera in a haemagglutination inhibition test. RESULTS: Four of the 18 isolates were obtained from indigenous (kampung) chickens, with the remainder being from typical intensive poultry production systems. The 18 isolates were obtained from 11 outbreaks that showed the typical clinical signs of infectious coryza and 11 of the isolates were obtained from chickens that had been vaccinated with infectious coryza vaccines. All 18 isolates were confirmed as H paragallinarum by biochemical testing and six isolates were also identified as H paragallinarum by the polymerase chain reaction test. Eleven isolates were resistant to erythromycin and streptomycin, 10 to neomycin, eight to oxytetracycline, five isolates to doxycycline, three to sulphamethoxazoltrimethoprim but only one to ampicillin. Seven isolates were Page serovar A, four were Page serovar B and seven were Page serovar C. CONCLUSION: The presence of all three Page serovars (A, B and C) has been confirmed for the first time in Indonesian chickens. As the majority of the infectious coryza vaccines in use in Indonesia contain only serovar A and C, the presence of serovar B in chickens indicates that the protection by these bivalent vaccines would be reduced. The use of trivalent infectious coryza vaccines that contain serovars A, B and C is recommended for use in Indonesia.  相似文献   

10.
The protection and level of hemagglutination-inhibition (HI) antibodies conferred in infectious coryza bivalent- and trivalent-immunized chickens against Avibacterium (Haemophilus) paragallinarum field isolates of the prevalent serovars in Mexico (A-1, A-2, B-1, and C-2) were investigated. The bivalent bacterin (A-1 and C-1) conferred significant protection and increased HI antibodies against isolates of serovars A-1, A-2, and C-2, but not against a serovar B-1 isolate. The trivalent bacterin (A-1, B-1, and C-2) conferred protection and increased HI antibodies against all four of the isolates. The results confirmed that in poultry areas where serovar B-1 is prevalent, the inclusion of this serovar in bacterins is needed to confer protection against infectious coryza caused by A. (H.) paragallinarum isolates of serovar B-1.  相似文献   

11.
Inactivated vaccines of Avibacterium paragallinarum provide protection and reduce the economic losses caused by infectious coryza. However, inactivated bacterins provide protection only against the Page serovars included in the vaccine. In this study, we investigated the immunological properties of a functional recombinant haemagglutinin protein (rHagA) derived from a Taiwan isolate strain A9 as the immunogen for vaccination. The rHagA subunit vaccine protected 71% of immunized chickens against 10(10) colony-forming units (CFU) of viable A9. Vaccinated chickens which showed no clinical signs of coryza developed haemagglutination inhibition (HI) titers of 1:10 or greater. Haemagglutination (HA) of serovars A and C was not affected by the presence of rHagA specific antiserum. The HA of rHagA could only be induced against formaldehyde-fixed chicken red blood cells (FA-RBCs). These results suggested that HagA is a moderate immunogen and might not be a major haemagglutinin in vivo. However, HagA might be involved in haemagglutination when treated serovar C aggregates fixed RBCs in vitro.  相似文献   

12.
本研究对国内市场上几个主要鸡传染性鼻炎灭活疫苗生产厂家生产的灭活疫苗免疫鸡只进行血清HI抗体水平测定和攻毒,比较不同公司所产疫苗效力的效力差异,并评估A、C型二价灭活疫苗两次免疫鸡群对国内B型分离株:DL-1株和最近从免疫失败鸡场分离到的SD-1株的交叉保护作用,分析免疫失败的原因.结果表明:A、D、E公司的疫苗免疫两次后,A型HI抗体阳性率分别为92.5%、100%和95%,滴度分别为33.9、55.1和59.9,攻毒保护率都是100%.C型HI抗体阳性率分别为72.5%、38.5%和77.5%,滴度分别为11.4、2.7和27,攻毒保护率分别为80%、70%和80%.而B和C公司的疫苗免疫两次后A型HI抗体阳性率分别为59.4%、77.1%,抗体滴度分别为5.4和21.8,攻毒保护率分别为50%和66.7%;C型HI抗体阳性率分别为54.1%和51.4%,抗体滴度分别为6.1和6.8,攻毒保护率分别为38.3%和50%.在五个疫苗产品中,以A、D、E的保护效力较好,B、C产品效力较差.另外,A、C型二价灭活疫苗免疫后不能对B型菌的攻击提供保护,其A、C型HI抗体阳性率、抗体滴度与对B型菌攻毒保护率无相关性.  相似文献   

13.
B型副鸡嗜血杆菌的分离鉴定   总被引:11,自引:2,他引:9  
从辽宁某公司鸡场疑似鸡传染性鼻炎的病鸡眶下窦分离到一株副鸡嗜血杆菌,用Page程序和Kume程序对其进行血清型鉴定,确认为B型副鸡嗜血杆菌,这是首次在我国分离到B型副鸡嗜血杆菌。  相似文献   

14.
本研究试图通过病原分离对安徽省某大型白羽肉鸡养殖公司持续出现疑似鸡传染性鼻炎的鸡群进行确诊,从不同批次发生鸡传染性鼻炎疑似症状的鸡体内分离细菌,经细菌分离、纯化、回鸡试验,共分离到8株细菌,经形态及培养特性、生化试验、血清学特性、16S rRNA基因序列分析等方法对分离的细菌进行鉴定。结果表明所分离的细菌有1株为A型副鸡禽杆菌,7株为B型副鸡禽杆菌,说明在安徽省某地持续引起幼龄肉鸡发生鸡传染性鼻炎的流行中B型致病株是优势毒株,显示新的流行特点。  相似文献   

15.
Four field isolates (S4, S10, S15, and S17) of Haemophilus paragallinarum were recovered from chickens affected with infectious coryza in widely separated regions of Japan. Their hemagglutinating (HA) activity and immunological properties were compared with those of strain 221 of serovar A/1 and strains Modesto and S1 of serovar C/2. When treated with potassium thiocyanate or hyaluronidase, all the isolates showed HA activity against formaldehyde-fixed chicken erythrocytes but not against fresh chicken erythrocytes. In the hemagglutination-inhibition (HI) test, the isolates cross-reacted with strains Modesto and S1 but not with strain 221. The immunological properties of these isolates, as determined by cross-protection tests, were similar to those of strain S1 and, to a lesser degree, strain Modesto, but not to strain 221. Our results indicated that the four field isolates belong to serovar C/2 and that the HI test is a suitable method for serotyping H. paragallinarum.  相似文献   

16.
To monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (SPF) chickens were introduced into two layer farms and reared with laying hens for 12 months. SPF chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. As a result, antibodies to eight or ten kinds of pathogens were detected in SPF chickens on each farm. Antibodies to infectious bronchitis virus (IBV), avian nephritis virus, Mycoplasma gallisepticum and M. synoviae were detected early within the first month. Antibody titer to IBV suggested that the laying chickens were infected with IBV repeatedly during the experiment on both farms. However, antibodies to infectious bursal disease virus and 6 pathogens were not detected.  相似文献   

17.
Infectious coryza in meat chickens in the San Joaquin Valley of California   总被引:1,自引:0,他引:1  
Two cases of infectious coryza in meat chickens are reported. The first case involved 6-week-old broiler chickens in which only Haemophilus paragallinarum was isolated. The second case involved 11-week-old roaster chickens in which H. paragallinarum and Mycoplasma synoviae were isolated. Both farms were in close proximity to layer-chicken farms where infectious coryza had been previously diagnosed. In both cases, only certain houses on the farm were affected, and mortality in these houses increased slightly. At processing, the condemnation rates for affected houses were considerably higher than rates for unaffected houses. Condemnations for affected houses were mostly due to airsacculitis. A dissecting fibronopurulent cellulitis was a prominent lesion in the second case. This lesion could lead to confusion with chronic fowl cholera and swollen-head syndrome.  相似文献   

18.
In South Africa the incidence of NAD-independent Haemnophilus paragallinarum isolation from clinical cases is increasing. This study was carried out to test whether a commercially available coryza vaccine (Nobilis Coryza, Intervet International BV) could protect chickens against challenge with recent NAD-independent isolates. SPF chickens were vaccinated twice at 3 and 7 weeks of age and were challenged at 9 weeks of age with 5 different NAD-independent isolates of serotype A or C-3. The results after challenge show that the coryza vaccine induces good protection against challenge with the different South African NAD-independent isolates of H. paragallinarum, including serotype C-3.  相似文献   

19.
应用当地分离株研制的鸡传染性鼻炎氢氧化铝胶灭活苗进行了免疫保护试验。并与油佐剂苗进行了比较,经对免疫鸡的抗体检测,攻毒后的临床症状,眶下窦中HPg分离表明鸡传染性鼻炎氢氧化铝胶苗优于油乳剂灭活苗。  相似文献   

20.
The aims of this study were the identification, cloning, and expression of a genetic region encoding an epitope that induces hemagglutination inhibition (HI) antibody against Avibacterium paragallinarum serovar A and an evaluation of the recombinant protein for immunogenicity in chickens. Although two monoclonal antibodies (MAbs) with HI activity, designated S24-951 and S7-1716-5C, were generated in this study, no reactive proteins with both MAbs were identified by Western blot analysis. A gene fragment of 5157 bp, designated hpa5. 1, was cloned from genomic DNA, and a recombinant protein expressed by hpa5.1, designated HPA5.1, reacted with both MAbs on dot-blot analysis. HPA5.1 showed no hemagglutinating activity, but significantly absorbed HI antibodies in the chicken immune serum. Analysis using a series of deletion mutants prepared from hpa5.1 indicated that a 4.8 kbp gene in hpa5.1 is essential for the expression epitope recognized by MAb S24-951. In addition, chickens immunized once with HPA5.1 showed a high protection rate with sufficient HI antibody titers against challenge exposure with a virulent strain of A. paragallinarum serovar A strain 221. These results show that hpa5. I1 is responsible for the expression of an epitope that induces HI antibody, and HPA5.1 might be a candidate for the development of a new vaccine against avian infectious coryza caused by A. paragallinarum serovar A.  相似文献   

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