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1.
Characterization of flagellin from Clostridium chauvoei.   总被引:1,自引:0,他引:1  
Differential centrifugation and cesium chloride-equilibrium centrifugation were used to purify the flagella from the strain Okinawa of the formalin-fixed Clostridium chauvoei. SDS-PAGE profile of purified flagella showed that a major protein band with a molecular mass of 46 kDa, corresponding to the flagellin monomer, and at least two minor protein bands with molecular masses of approximately 73 and 100 kDa were found. The amino acid composition of C. chauvoei flagellin was similar to the flagellin of Salmonella typhimurium and Bacillus subtilis. In addition, C. chauvoei flagellin monomer shared limited sequence homology with the N-terminal amino acid sequence reported for other bacterial flagellins. N-terminal sequences of two minor bands corresponded to the flagellin monomer, indicating that higher molecular mass bands were polymeric forms of the flagellin monomer.  相似文献   

2.
Using ammonium sulphate fractionation, the Clostridium chauvoei hemolysin was purified by cation exchange chromatography and sephacryl S-100 gel filtration. The molecular mass of the hemolysin, determined by SDS-PAGE was found to be approximately 27kDa. The activity of the hemolysin was determined in erythrocytes of various animals, with sensitivities observed in the order of cow, sheep, chicken, rabbit, rat, mouse, dog and horse. Temperature affected the sensitivity of erythrocytes to C. chauvoei hemolysin. These results may reflect distinct characteristics of the hemolytic activity of C. chauvoei hemolysin and that the hemolysin may be pore-forming.  相似文献   

3.
Clostridium chauvoei causes blackleg, which is difficult to distinguish from the causative clostridia of malignant edema. Therefore, a single-step PCR system was developed for specific detection of C. chauvoei DNA using primers derived from the 16S-23S rDNA spacer region and partial 23S rDNA sequences. The specificity of the single-step PCR system was demonstrated by testing 37 strains of clostridia and 3 strains of other genera. A 509 bp PCR product, which is a C. choauvoei-specific PCR product, could be amplified from all of the C. chauvoei strains tested, but not from the other strains. Moreover, this single-step PCR system specifically detected C. chauvoei DNA in samples of muscle from mice 24 hr after inoculation with 100 spores of C. chauvoei, and in clinical materials from a cow affected with blackleg. These results suggest that our single-step PCR system may be useful for direct detection of C. chauvoei in culture and in clinical materials from animals affected with blackleg.  相似文献   

4.
The polymerase chain reaction (PCR) was used to amplify specific segments of the 16S ribosomal RNA gene of Clostridium chauvoei, a major pathogen of ruminants. Three sets of primers were used to produce amplicons of 159, 836 and 959 base pairs (bp), respectively. The PCR was evaluated by testing clinically important strains of Clostridium, including 21 strains of C. chauvoei, five strains each of Clostridium septicum and Clostridium perfringens and two strains each of Clostridium novyi, Clostridium histolyticum and Clostridium sordellii. Both purified DNA and biomass from pure cultures of each of these microorganisms were evaluated as templates in the PCR. In addition, extracts of formalin-fixed, paraffin-embedded tissues of eight sheep experimentally inoculated with C. chauvoei or C. septicum (four animals each) were also tested by the PCR using the three sets of primers. Purified DNA template of all C. chauvoei strains produced PCR amplicons of the expected size for all three primer pairs. However, when biomass from pure cultures of C. chauvoei or tissue extracts were used as templates, only the primer pair designed to produce the 159bp amplicon gave consistently positive results. No positive results were obtained with any primer pair when purified DNA or biomass from pure cultures of non-target clostridial species were used as templates. Therefore, the PCR primer sets appear to be very specific for identifying C. chauvoei in both cultures and tissues.  相似文献   

5.
Amplification of the 16S-23S rDNA spacer region by polymerase chain reaction (PCR) was used for the rapid detection of Clostridium chauvoei and C septicum. To assess its specificity, PCR was performed with total DNA from 42 strains of clostridia and three strains of other genera. PCR products specific to C chauvoei or to C septicum were generated from homologous cultures only. Clostridium chauvoer-specific or C septicum-specific amplicons were also generated from tissues of cows experimentally infected with C chauvoei or C septicum and in DNA samples from cows clinically diagnosed as having blackleg or malignant oedema. These results suggest that a species-specific PCR may be useful for the rapid and direct detection of C chauvoei and C septicum in clinical specimens.  相似文献   

6.
We developed a one-step polymerase chain reaction (PCR) system that specifically detects Clostridium chauvoei. Oligonucleotide primers were designed to amplify a 516-bp fragment of the structural flagellin gene. The specificity of the PCR was investigated by analyzing 59 strains of clostridia, and seven strain of other genera. A 516-bp fragment could be amplified from all the C. chauvoei strains tested, and no amplification was observed by using DNAs from the other strains tested, including Clostridium septicum. Similarly, this PCR-based method specifically detected C. chauvoei DNA sequences in samples of muscle and exudate of obtained from mice within 12h of inoculation. In tests using samples of muscle or liver, the limit of detection was about 200 organisms per reaction. These results suggest that the one-step PCR system may be useful for direct detection and identification of C. chauvoei in clinical specimens.  相似文献   

7.
The anaerobic bacillus Clostridium chauvoei is the causative agent of blackleg, a lethal disease that has an important impact on the sheep and cattle industry worldwide. Immunity to C. chauvoei is considered to be mainly anticellular, and for this reason there is scarce information about the immunogenicity of extracellular proteins. In this work variations in protein profiles, immune response by ELISA and protective capacity of culture supernatants of three C. chauvoei strains, collected at different growth phases, are reported. Sera raised against extracellular antigens also recognised cellular antigens of the same molecular masses. Partially purified cell-free supernatants and those concentrated 10 times by ultrafiltration (C-CFS), obtained at the early stationary phase of growth, induced a strong immunoprotective response, even at low doses, that was more marked for C. chauvoei strain ATCC 10092 (p < or = 0.05). With C-CFS formulations, a clear relationship was observed between IgG titres, protective capacity and concentration of the antigen doses, indicating a specific immune response.  相似文献   

8.
二重PCR方法鉴别气肿疽梭菌和腐败梭菌   总被引:1,自引:1,他引:0  
用包含16S~23S rDNA间隔区和23S rDNA的部分序列作为气肿疽梭菌特异性标志,以α毒素部分序列作为腐败梭菌特异性标志,建立了鉴别气肿疽梭菌和腐败梭菌的二重PCR方法。结果显示:气肿疽梭菌C54-1株扩增出大小为509 bp的条带,腐败梭菌C55-1株、C55-16株均扩增出大小为148 bp的条带,均与预期吻合;而产气荚膜梭菌C57-1株、C59-37株,肉毒梭菌C62-4株,诺维梭菌C61-4株均未扩增出任何条带。扩增产物的测序结果进一步证实了本方法的特异性。菌株的生物学特性试验结果也符合相应气肿疽梭菌和腐败梭菌的特点。本研究所建立的二重PCR方法可用于气肿疽梭菌和腐败梭菌的快速鉴定。  相似文献   

9.
Reannotation of the pathogenic Mycoplasma gallisepticum strain R(low) genome identified the hypothetical gene MGA_0329 as a homolog of the sialidase gene MS53_0199 of Mycoplasma synoviae strain MS53. Potent sialidase activity was subsequently quantitated in several M. gallisepticum strains. Because sialidase activity levels correlate significantly with differing M. synoviae strain virulence, we hypothesized this enzyme may also influence the virulence of M. gallisepticum. MGA_0329 was disrupted in strain R(low) to create mutants 6, 358 and P1C5, which resulted in the loss of sialidase activity in all three mutants. Chickens infected with the knockout mutants had significantly less severe (P<0.05) tracheal lesions and tracheal mucosal thickening than chickens infected with equal doses of strain R(low). Significantly fewer (P<0.05) CCU especially of strains 6 and P1C5 were recovered at necropsy. Mini-Tn4001tet plasmid pTF20 carrying a wild-type copy of MGA_0329 with its native promoter was used to complement the genetic lesion in strain P1C5. Three clones derived from P1C5, each having one copy of MGA_0329 stably transposed into a different site in its genome, expressed sialidase restored to wild-type activity levels (1.58×10(-8)U/CFU). Complementation of P1C5 with MGA_0329 did not restore it to wild-type levels of virulence, indicating that the contribution of sialidase to M. gallisepticum virulence is not straightforward.  相似文献   

10.
The whole cell soluble antigens of two strains (VPB 3457 and VPB 3492) of feline Porphyromonas gingivalis were analysed by Western blotting using serum taken from 40 domestic cats with various grades of periodontal disease. Five strongly immunogenic protein bands (70, 34, 27, 24 and 19kDa) from VPB 3457 and seven from VPB 3492 (58, 44, 34, 27, 25, 24 and 21kDa) were selected for further study. A significant positive correlation was found between the serum antibody response to the 70, 34, 27, 24 and 19kDa bands of VPB 3457 and the 58, 44, 25, 24 and 21kDa bands of VPB 3492 and the overall periodontal grade. A significant positive correlation was also found between the serum antibody response to the 24kDa band of VPB 3457 and the total colony forming units of P. gingivalis. N-terminal sequencing of the 44kDa band of VPB 3492 showed 75% identity with the translated amino acids from the hag A (haemagglutinin) gene of a human strain of P. gingivalis and N-terminal amino acid sequence of the 27kDa band of VPB 3457 showed 88% identity with the amino acid sequences translated from DNA of purported genes coding for variously named proteinases of human strains of P. gingivalis.  相似文献   

11.
May M  Kleven SH  Brown DR 《Avian diseases》2007,51(4):829-833
Eleven strains of the avian pathogen Mycoplasma synoviae were evaluated for the presence of sialidase activity with the use of the fluorogenic substrate 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid and the sialidase inhibitor 2-deoxy-2,3- didehydro-N-acetylneuraminic acid. The kinetics of in vitro growth in modified Frey medium were also assessed for each strain. Five strains had been isolated from clinically symptomatic chickens, and strains WVU 1853T and K3344 have been demonstrated to be capable of reproducing disease in specific-pathogen-free chickens. All strains exhibited sialidase activity, although the amount varied 65-fold among strains (P < 0.0001) from 1.3 x 10(-7) to 2.0 x 10(-9) activity units per colony-forming unit. Strains originally isolated from clinically symptomatic birds had more (P < 0.05) sialidase activity than strains from asymptomatic birds. Strain WVU1853T exhibited the most sialidase activity (P < 0.0001) and grew to the highest culture density (P < 0.0001) among strains, but across strains, the rank correlation of growth rate with sialidase activity was not significant. Negligible activity was detected in conditioned culture supernatant fluid. This is the first report of sialidase activity in pathogenic strains of M. synoviae, which suggests a potential enzymatic basis for virulence of the organism.  相似文献   

12.
转基因动物产品-人乳铁蛋白与测定方法   总被引:4,自引:0,他引:4  
乳铁蛋白是一种分子量为76.386kDa的结合性糖蛋白,在其多肽链上有两条碳水化合物侧链,乳铁蛋白存在于人乳及牛乳中,乳腺为主要分泌器官,乳铁蛋白具有多种重要的生理功能,在多种免疫细胞表面存在乳铁蛋白受体,编码人乳铁蛋白的基因全长2.358kb,由其释译的最初乳铁蛋白为711个氨基酸残基,成熟乳铁蛋白为692个氨基酸残基,人乳铁蛋白的转基因研究已获成功,获得表达,并初步应用于临床治疗,乳铁蛋白的检测方法包括酶联免疫吸附试验(ELISA),放射免疫(RIA),免疫卵迹(Western-Blot)及免疫组化方法,还可应用PCR和核酸探针技术对人乳铁蛋白转基因肉品进行检测。  相似文献   

13.
Mammary-associated serum amyloid A 3 (M-SAA3) was secreted at highly elevated levels in bovine, equine and ovine colostrum and found at lower levels in milk 4 days postparturition. N-terminal sequencing of the mature M-SAA3 protein from all the three species revealed a conserved four amino acid motif (TFLK) within the first eight residues. This motif has not been reported to be present in any of the hepatically-produced acute phase SAA (A-SAA) isoforms. Cloning of the bovine M-Saa3 cDNA from mammary gland epithelial cells revealed an open reading frame that encoded a precursor protein of 131 amino acids which included an 18 amino acid signal peptide. The predicted 113 residue mature M-SAA3 protein had a theoretical molecular mass of 12,826Da that corresponded with the observed 12.8kDa molecular mass obtained for M-SAA3 in immunoblot analysis. The high abundance of this extrahepatically produced SAA3 isoform in the colostrum of healthy animals suggests that M-SAA3 may play an important functional role associated with newborn adaptation to extrauterine life and possibly mammary tissue remodeling.  相似文献   

14.
Clostridium chauvoei is a causative agent of blackleg and the major protective antigen of the organism is the flagellar protein. Using an Escherichia coli expression library of the C. chauvoei Okinawa strain, we isolated the fliC gene encoding the flagellin protein. DNA sequence analysis revealed an open reading frame of 413 amino acid residues with a calculated molecular mass of 43819Da. Comparison of the sequence with those of flagellins from other bacteria showed considerable homology in the N-terminal and C-terminal domains. The glutathione-S-transferase (GST)-flagellin fusion protein and the purified FliC protein after removing the GST part with thrombin reacted with both polyclonal antisera and the non-protective monoclonal antibody (Mab), Mo-114. However, the protective Mab, Mo-41, which may recognize its conformational epitope, failed to react with both the GST-flagellin fusion protein and the purified FliC. Furthermore, the GST-flagellin fusion protein and the purified FliC induced very little protective immunity in mice. These results suggested that a conformation-dependent epitope play an important role in the development of immunity against blackleg.  相似文献   

15.
We produced monoclonal antibodies (mAbs) against bovine herpesvirus type 1 (BHV-1), Los Angeles strain, and then evaluated them as potential candidates for preparing diagnostic reagents. Of the 318 cell lines expressing antibodies to the virus, 60% (192) secreted IgG and 40% (126) secreted IgM. Twenty-six mAbs were selected based on enzyme-linked immunosorbent assay (ELISA) and virus neutralization (VN) titers and characterized by immunoprecipitation, immunofluorescence and immunoblots. The selected mAbs were assigned to one of four groups based on their immunoprecipitation patterns. Group A (4 mAbs) precipitated a complex of three glycoproteins with molecular weight (MW) 130 kDa, 72 kDa and 55 kDa, which presumably represented gI of BHV-1. Monoclonal antibodies of this group were highly reactive in ELISA but had low VN titers. Group B (4 mAbs) precipitated a glycoprotein with MW of 71 kDa (gIV). This group of mAbs had high VN titers. Group C (16 mAbs) precipitated a 97 kDa glycoprotein (gIII). Monoclonal antibodies of this group had high ELISA but low VN titers. Group D (2 mAbs) precipitated a double band of non-glycosylated proteins with MW of 37/32 kDa; these proteins could not be assigned to any of the antigens of BHV-1 previously described. ELISA and VN titers of this group of mAbs were low. To test the antigenic variability of the antigenic determinants which were recognized by these 4 groups of mAbs, we adapted Madin Darby bovine kidney cell-propagated BHV-1 Los Angeles strain to Crandell's feline kidney cell line. After the tenth passage in feline kidney cells, the epitopes on the 37/32 kDa peptide recognized by the mAbs group D were no longer detectable. Additional changes were noted in the electrophoretic mobility of the 130 kDa and 71 kDa glycoproteins (gI) identified by mAb of group A shifted downward. The 71 kDa glycoprotein (gIV) reactive with mAb group B and the 97 kDa (gIII) reactive with mAb group C remained stable. Since clone No. 191 of group B mAb was potent in ELISA, VN, immunoblots and immunofluorescence, and recognized an epitope which did not change under selective pressure, we feel that the mAb produced by this clone are a good candidate for the production of diagnostic reagents.  相似文献   

16.
To establish a possible relationship between resistance to complement, virulence and outer membrane protein banding patterns, ten E. coli O2 strains isolated from chickens with colibacillosis were studied for: (1) resistance to the bactericidal effect of complement by a quantitative microtiter method, (2) virulence, as determined by chicken lethality test, and (3) outer membrane protein banding patterns yielded by SDS-polyacrylamide gel electrophoresis. The ten isolates were classified into three groups: (1) Group 1, consisting of four isolates showed: (a) high resistance to complement, (b) high virulence, and (c) different pattern between 35 and 40 kDa with a weak peptide band at 35 kDa. (2) Group 2, consisting of one isolate showed: (a) high resistance to complement, (b) low virulence, and (c) a weak peptide band at 35 kDa. (3) Group 3, consisting of five isolates showed: (a) low resistance to complement, (b) low virulence, and (c) identical OMP pattern between 35 and 40 kDa exhibiting a strong peptide band at 35 kDa. The results suggest that high resistance to complement may be necessary but no sufficient for virulence and that OMP banding patterns may be a marker for virulence.  相似文献   

17.
Neuraminidases are virulence factors in many pathogenic microorganisms. They are present also in some Mycoplasma species that cause disease in birds, dogs and alligators. Thirty-seven Mycoplasma species have been examined previously for neuraminidase (sialidase) activity, whereas many of the species causing disease in man, ruminants, pigs, rodents and other animals have not. In this study neuraminidase enzymatic activity (NEAC) was examined in 45 previously untested Mycoplasma species, including those causing diseases in man, farm animals and laboratory animals. The only species in which NEAC was found was Mycoplasma neurolyticum, specifically, its type strain (Type A(T)) which is capable of inducing neurologic signs in inoculated young mice and rats. The NEAC of washed cells was relatively weak, but it differed even more than 10-fold among cells of cultures derived from individual colonies of M. neurolyticum. A weak NEAC was also detected in the supernatant of the M. neurolyticum broth culture. Canine Mycoplasma spp. with high sialidase activity reported previously, Mycoplasma canis, Mycoplasma cynos and Mycoplasma molare had 100-fold more NEAC than M. neurolyticum, but apparent differences in NEAC levels existed among strains of M. canis and of M. cynos. Zymograms using neuraminidase-specific chromogenic substrate were used to show proteins having NEAC. In M. canis (a field isolate Larissa and the type strain PG14(T)), M. cynos (isolate 896) and M. molare (type strain H542(T)) proteins with NEAC had molecular masses of ~130kDa, 105kDa and 110kDa, respectively. Identification of these neuraminidases could provide the basis for their molecular characterization.  相似文献   

18.
采用RT-PCR方法从鸭腿肌总RNA中扩增了鸭核心蛋白聚糖基因编码区序列,进行序列分析,并将编码鸭核心蛋白聚糖成熟蛋白的核酸片段连入原核表达载体pET-32a(+)中,加入IPTG诱导其表达后,亲和层析纯化表达的蛋白。采用SDS-PAGE检测,用质谱方法对表达的蛋白进行鉴定。研究成功克隆出鸭核心蛋白聚糖基因编码区序列,序列分析表明,鸭DCN编码区序列由1074个碱基组成,编码357个氨基酸,其中信号肽有16个氨基酸。将鸭DCN蛋白划分为9个结构域(LRR1-9),结合人DCN序列进行序列分析推测结构域中LRR4、5与TGF-β可能存在一定关系。SDS-PAGE检测和质谱鉴定结果表明获得了分子量为54.7ku的鸭DCN融合蛋白。  相似文献   

19.
为分析猫泛白细胞减少症病毒(FPV)北京株(FPV-BJ 05株)NS1基因的分子特征及其编码蛋白的生物学功能,本研究对FPV-BJ 05株NS1基因进行PCR扩增、克隆及序列测定。应用生物信息学软件分析FPV-BJ 05株与GenBank上登录的11株FPV参考株NS1基因的同源性,并预测NS1蛋白理化性质、信号肽、跨膜结构、B细胞抗原表位、磷酸化位点、亚细胞定位及蛋白结构与功能、高级结构等。结果显示,NS1基因全长2 007 bp,编码668个氨基酸,且与其他FPV分离株NS1基因核苷酸序列同源性为98.8%~99.3%,氨基酸序列同源性为97.9%~98.8%。系统进化树分析结果显示,FPV-BJ 05株NS1蛋白与GenBank上登录的3株FPV参考株处于同一大分支,但由于氨基酸的突变导致其属于独立的一小分支。NS1蛋白既无信号肽也无跨膜结构域,属于非分泌型的疏水性蛋白。B细胞抗原表位预测结果显示,NS1蛋白柔韧性较好,抗原性及表面可及性较高,预测该蛋白含有13个优势抗原位点。修饰结构预测表明,NS1蛋白含有62个潜在磷酸化位点,27个O-糖基化位点和2个N-糖基化位点。亚细胞定位结果显示,NS1蛋白在细胞质和细胞核的概率较高,分别为69.6%和17.4%。NS1蛋白二级结构中α-螺旋、延伸链、无规则卷曲和β-转角分别占39.37%、15.42%、39.37%和5.84%。应用在线软件SWISS-Modle对NS1蛋白进行建模,预测其三级结构,结果发现NS1蛋白主要以α-螺旋为主。本试验结果将为北京地区FPV免疫诊断及核酸疫苗研究提供理论依据。  相似文献   

20.
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