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1.
Ovodov YS 《Biochemistry. Biokhimii?a》2006,71(9):955-961
The role of bacterial capsular antigens represented in capsular polysaccharides and exoglycans in pathogenicity and virulence
of bacteria is discussed in this review. Using capsular antigens for vaccines against severe diseases caused by capsular microorganisms
is considered in detail. The use of conjugates of capsular polysaccharides and their fragments with proteins and peptides
for vaccine as well as using liposomes as adjuvants for the capsular antigens are described. Data concerning structural elucidation
of bacterial capsular antigens are given in the first part of this review.
Published in Russian in Biokhimiya, 2006, Vol. 71, No. 9, pp. 1175–1182. 相似文献
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《Saudi Journal of Biological Sciences》2017,24(2):367-370
The use of molecular techniques for detection and characterization of the Pasteurella multocida is very important for rapid and specific detection and characterization of the organism. During the period from 15th February, 2014 to 15th April, 2015, 425 nasopharyngeal swabs and 175 lung and spleen samples were collected and examined by conventional methods, 80 strains (18.82%) of P. multocida were isolated from the calves, sheep and goat with respiratory manifestation. Meanwhile, 77 strains (44%) were isolated from emergency slaughtered animals. All the recovered strains were positive for specific PCR for detection of P. multocida strains previously identified as P. multocida by standard microbiological techniques. Multiplex PCR for molecular typing of the capsular antigens of the recovered P. multocida revealed positive amplification of 1044 bp fragments specific to the capsular antigen type A with 105 strains (66.88%), and amplification 511 bp fragments of the capsular antigen type E with 52 strain (33.12%) and absence of B, D and F antigens. Multiplex PCR for molecular typing of the capsular antigens of P. multocida can be used as a simple, sensitive, rapid, reliable technique instead of the serological techniques for identification of the capsular antigens of P. multocida 相似文献
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Piven' NN Avrorova IV Zhukova SI Drefs NM Lomova LV Proshina OB Alekseev VV Kapliev VI 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2007,(3):86-89
Test-system using index of phagocytosis of noncapsulated mutant loaded by one of the several capsular antigenic complexes was developed and used for screening for both immunogenic and protective capsular antigens of B. mallei. Direct correlation between index of phagocytosis, level of delayed-type hypersensivity, and protective effect of capsular antigens has been shown on the model of experimental melioidosis in susceptible white mice, guinea pigs and white rats. Obtained results let to use the developed test-system for initial selection of B. mallei protective capsular antigens and their further study as potential components of preparations for specific prophylaxis of glanders and melioidosis. 相似文献
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Piven' NN Avrorova IV Zhukova SI Alekseev VV Khrapova NP Korsakova II Lomova LV Napalkova GM Drefs IM Proshina OB 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2007,(1):47-52
Study showed that five (C3, C6, C9, C10, C11) out of ten chromatographic fractions of surface and capsular antigens of B. mallei significantly stimulated cell-mediated immunity that manifested in activation of delayed hypersensivity reactions (DHS) and phagocyteability of noncapsulated avirulent strain of B. mallei with added surface and capsular antigenic complexes. Other fractions did not stimulate cell-mediated immunity, furthermore, fraction C8, which contained capsular biopolymer with mass of 200 kD (Ar8), was characterized by immunosuppressive effect on DHS and phagocytosis. Observed stimulation of cell-mediated immunity by fractions referred above has been confirmed by assessment of their protective effects on the model of experimental melioidosis in white rats. Relationship between markers of humoral and cell-mediated immunity, including markers of specific response, was not observed. 相似文献
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Heat-stable serotyping antigens expressed by strains of Campylobacter jejuni are probably capsular and not long-chain lipopolysaccharide 总被引:1,自引:0,他引:1
H. Chart J.A. Frost A. Oza R. Thwaites S. Gillanders B. Rowe 《Journal of applied microbiology》1996,81(6):635-640
The role of lipopolysaccharide (LPS) in the serotyping of Campylobacter jejuni based on heat-stable antigens was examined using SDS-PAGE and a silver stain for carbohydrate. None of the 32 type strains of Camp. jejuni expressed long-chain LPS. Rabbit antibodies, prepared to 10 selected strains of Camp. jejuni , reacted with surface-exposed carbohydrate antigens, which were not LPS. This study suggests that the heat-stable antigens of Camp. jejuni , which form the basis for the established Penner serotyping scheme, are probably capsular and not LPS. 相似文献
8.
Molecular cloning and expression of the genes encoding the Escherichia coli K4 capsular polysaccharide, a fructose-substituted chondroitin 总被引:2,自引:0,他引:2
C.R. Drake I.S. Roberts B. Jann K. Jann G.J. Boulnois 《FEMS microbiology letters》1990,66(1-3):227-230
The majority of capsular polysaccharides (K antigens) are linear molecules and their genes have a common functional organisation encoding common steps in capsule biogenesis. However, the K4 antigen is a substituted polymer composed of a chondroitin backbone with a fructose side chain. In order to determine whether K4 biosynthesis uses these common mechanisms the K4 antigen genes were cloned. DNA probes taken from the two conserved regions of the K1 genes were used to isolate one plasmid, pRD1, homologous to both probes. Immunological analysis was used to show that pRD1 directs the production of the substituted K4 antigen on the cell surface. Southern hybridisation was used to show that the cloned genes are organised in the same way as other K antigen gene clusters. We conclude that the branched K4 antigen is handled by the same post-polymerisation mechanisms as other linear K antigens. 相似文献
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Xiaoyu Liu Lizhen Wang Chengfei Du Deyu Li 《Computer methods in biomechanics and biomedical engineering》2013,16(8):914-921
Blunt impact on the eye could results in lens capsular rupture that allows foreign substances to enter into the lens and leads to cataract formation. This paper aimed to investigate the mechanism of lens capsular rupture using finite element (FE) method. A FE model of the human eye was developed to simulate dynamic response of the lens capsule to a BB (a standard 4.5-mm-diameter pellet) impact. Sensitivity studies were conducted to evaluate the effect of the parameters on capsular rupture, including the impact velocity, the elastic modulus of the lens, the thickness and the elastic modulus of the lens capsule. The results indicated that the lens was subjected to anterior compression and posterior intension when the eye was stricken by a BB pellet. The strain on the posterior capsule (0.392) was almost twice as much as that on the anterior capsule (0.207) at an impact velocity of 20 m/s. The strain on the capsule was proportional to the impact velocity, while the capsular strain showed no significant change when the lens modulus elastic varied with age. The findings confirmed that blunt traumatic capsular rupture is the result of shockwave propagation throughout the eye. The posterior capsule is subjected to greater tension in blunt trauma, which is the main cause that ruptures are more commonly found on the posterior capsule than the anterior capsule. Also, thinner thickness and lower elastic modulus would contribute to the posterior capsular rupture. 相似文献
10.
Coexpression of colanic acid and serotype-specific capsular polysaccharides in Escherichia coli strains with group II K antigens. 总被引:3,自引:2,他引:1 下载免费PDF全文
In Escherichia coli K-12, the rcsA and rcsB gene products are positive regulators in expression of the slime polysaccharide colanic acid. We have previously demonstrated the presence of rcsA sequences in E. coli K1 and K5, strains with group II capsular K antigens, and shown that introduction of multicopy rcsA into these strains results in the expression of colanic acid. We report here the presence of rcsB sequences in E. coli K1 and K5 and demonstrate that RcsB also plays a role in the biosynthesis of colanic acid in strains with group II K antigens. In E. coli K1 and K5 grown at 37 degrees C, multicopy rcsB and the resulting induction of colanic acid synthesis had no significant effect on synthesis of the group II K antigens. K-antigen-specific sugar transferase activities were not significantly different in the presence or absence of multicopy rcsB, and introduction of a cps mutation to eliminate colanic acid biosynthesis in a K1-derivative strain did not influence the activity of the polysialyltransferase enzyme responsible for synthesis of the K1 polymer. Furthermore, immunoelectron microscopy showed no detectable difference in the size or distribution of the group II K-antigen capsular layer in cells which produced colanic acid. Colanic acid expression therefore does not appear to significantly affect synthesis of the group II K-antigen capsule and, unlike for group I K antigens, expression of group II K antigens is not positively regulated by the rcs system. 相似文献
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We have isolated the capsular polysaccharide from the strain ofShigella dysenteriae type 1 8337. The product was purified by ultracentrifugation, treated with enzymes (proteinase K, DNA-RNAase) and analyzed
by immunochemical methods. Polyclonal antibodies were obtained from rabbits immunized by whole cell antigens prepared fromShigella by ultrasonic treatment and by purified capsular polysaccharide. Crossed immunoelectrophoresis, PAGE and Western blot analysis
showed that this product containing mainly the polysaccharide component also contained glycoprotein and lipopolysaccharide.
Double diffusion in agarose gel confirmed that the capsular preparation contained at least three antigens reacting with rabbit
polyclonal antiserum. 相似文献
12.
Lankinen KS Rintamäki S Syrjänen R Kilpi T Ruutu P Leinonen M 《Journal of microbiological methods》2004,56(2):193-199
We developed a new competitive EIA method for the demonstration of pneumococcal capsular polysaccharides from respiratory samples. The pediatric types 4, 6B, 9V, 14, 18C, 19F and 23F were selected for this study, because these capsular polysaccharides were included in the first heptavalent pneumococcal conjugate vaccines, which were used in the Finnish Otitis Media Vaccine Trial. Sensitivity of the EIA tests for purified polysaccharide antigens varied between 5 and 100 ng/ml, depending on the type. The assays performed well in 100 nasopharyngeal samples (NPS) samples processed through an enrichment culture, with an almost 100% sensitivity compared with routine culture. The method appeared type-specific, except that EIA for 6B capsule also detected 6A. The method is applicable for type-specific identification of pneumococcus in carriage studies. 相似文献
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T cell independent antigens do not require T cell help to induce an immune response, and are characterized by a lack of immunologic memory. These antigens can be divided into two classes, TI-1 or TI-2. TI-1 antigens, such as bacterial lipopolysaccharide, are potent B-cell mitogens, capable of non-specific, polyclonal activation of B cells. In contrast, TI-2 antigens can only activate mature B cells and consist of highly repetitive structures, such as capsular polysaccharides (CPS) from bacteria. Many vaccines currently in use consist of purified capsular polysaccharides from pathogenic bacteria such as Streptococcus pneumoniae and Neisseria meningitidis. These vaccines are efficacious in immune-competent adults, however, due to their TI-2 nature, are not effective in children <2 years of age. Converting polysaccharides into T cell dependent (TD) antigens, allows children, <2, to produce an effective immune response. This review focuses on various strategies used to convert the immune response to polysaccharide antigens from TI-2 to a TD response. Conjugate vaccines, anti-idiotypic antibodies, phage display library technology and DNA vaccines are discussed. 相似文献
14.
Samantha S. Wear Caitlin Sande Olga G. Ovchinnikova Andrew Preston Chris Whitfield 《The Journal of biological chemistry》2022,298(1)
Salmonella enterica serovar Typhi causes typhoid fever. It possesses a Vi antigen capsular polysaccharide coat that is important for virulence and is the basis of a current glycoconjugate vaccine. Vi antigen is also produced by environmental Bordetella isolates, while mammal-adapted Bordetella species (such as Bordetella bronchiseptica) produce a capsule of undetermined structure that cross-reacts with antibodies recognizing Vi antigen. The Vi antigen backbone is composed of poly-α-(1→4)-linked N-acetylgalactosaminuronic acid, modified with O-acetyl residues that are necessary for vaccine efficacy. Despite its biological and biotechnological importance, some central aspects of Vi antigen production are poorly understood. Here we demonstrate that TviE and TviD, two proteins encoded in the viaB (Vi antigen production) locus, interact and are the Vi antigen polymerase and O-acetyltransferase, respectively. Structural modeling and site-directed mutagenesis reveal that TviE is a GT4-family glycosyltransferase. While TviD has no identifiable homologs beyond Vi antigen systems in other bacteria, structural modeling suggests that it belongs to the large SGNH hydrolase family, which contains other O-acetyltransferases. Although TviD possesses an atypical catalytic triad, its O-acetyltransferase function was verified by antibody reactivity and 13C NMR data for tviD-mutant polysaccharide. The B. bronchiseptica genetic locus predicts a mode of synthesis distinct from classical S. enterica Vi antigen production, but which still involves TviD and TviE homologs that are both active in a reconstituted S. Typhi system. These findings provide new insight into Vi antigen production and foundational information for the glycoengineering of Vi antigen production in heterologous bacteria. 相似文献
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Abstract Coliphage K30, a bacteriophage specific for strains bearing the Escherichia coli serotype K30 capsular polysaccharide, produced plaques surrounded by extensive haloes, a characteristic of phage which produce capsule depolymerase (glycanase) enzymes. Klebsiella K20, a strain producing a capsular polysaccharide chemically identical to that of E. coli K30, was not lysed by coliphage K30, although the bacteriophage encoded glycanase enzyme did degrade the K20 polysaccharide. Morphologically, coliphage K30 belonged to Bradley group C. The coliphage K30 particle comprised 20 structural polypeptides which varied from 9.5–136 kDa and genomic DNA of 38.7 ± 1.0 kb. 相似文献
17.
Applications of fluorescent antibody for detecting capsular substances in Staphylococcus epidermidis 总被引:6,自引:3,他引:3
Y. Ichiman 《Journal of applied microbiology》1984,56(2):311-316
I chiman , Y. 1984. Applications of fluorescent antibody for detecting capsular substances in Staphylococcus epidermidis, Journal of Applied Bacteriology 56 , 311–316.
A fluorescent antibody technique was developed for the determination of the type of capsule of strains of Staphylococcus epidermidis . Many mouse virulent and avirulent strain populations were investigated. Of 300 fresh isolates of Staph. epidermidis , 27 were mouse virulent strains and of these 74.1% and 25.9% were mono- and polyvalent, respectively. The frequency of capsular type antigens I, II and III, produced by the 27 virulent strains was found to be 18.5%, 88.9% and 18.5%, the majority being capsular type II. In the mouse avirulent strains, capsular type antigen production was demonstrated in 263 out of 273 strains examined and mono- and polyvalent capsular types comprised 52.3% and 44.0%, respectively. Capsular type I, II, III strains and non-typable strains occurred at frequencies of 15.0%, 95.2%, 34.9% and 3.7% respectively, the majority of mouse avirulent strains also being capsular type II. These results indicate that a majority of ordinary Staph. epidermidis produce capsular type antigens although the capability is quantitatively different according to strain. 相似文献
A fluorescent antibody technique was developed for the determination of the type of capsule of strains of Staphylococcus epidermidis . Many mouse virulent and avirulent strain populations were investigated. Of 300 fresh isolates of Staph. epidermidis , 27 were mouse virulent strains and of these 74.1% and 25.9% were mono- and polyvalent, respectively. The frequency of capsular type antigens I, II and III, produced by the 27 virulent strains was found to be 18.5%, 88.9% and 18.5%, the majority being capsular type II. In the mouse avirulent strains, capsular type antigen production was demonstrated in 263 out of 273 strains examined and mono- and polyvalent capsular types comprised 52.3% and 44.0%, respectively. Capsular type I, II, III strains and non-typable strains occurred at frequencies of 15.0%, 95.2%, 34.9% and 3.7% respectively, the majority of mouse avirulent strains also being capsular type II. These results indicate that a majority of ordinary Staph. epidermidis produce capsular type antigens although the capability is quantitatively different according to strain. 相似文献
18.
The role of Klebsiella pneumoniae K- and O-polysaccharide antigens was determined in a rat model of lobar pneumonia. The induction of experimental infection in rats by wild-type strain, and its lipopolysaccharide- and capsular polysaccharide-deficient mutants was compared. Though the mutant lacking both antigens (K- O-) induced infection it could not successfully establish itself in the rat lung. It caused only mild infection, as compared to the wild type strain (K+ O+) and the strain lacking CPS alone (K- O+). Besides capsular polysaccharide, the lipopolysaccharide antigen was shown to be an important factor in pathogenesis of K. pneumoniae acute respiratory tract infection. 相似文献
19.
K V Chernyak AYaAntonov N K Kochetkov L N Padyukov N V Tsvetkova 《Carbohydrate research》1985,141(2):199-212
The synthesis of the allyl beta-glycosides (8 and 20, respectively) of beta-D-GlcpA-(1----4)-D-Glcp and beta-D-Glcp-(1----3)-D-GlcpA (overlapping disaccharide fragments A and B) in the linear chain of the capsular polysaccharide (S3) from Streptococcus pneumoniae type 3 is described. Oxidation of allyl 2,3,6,2',3',4'-hexa-O-acetyl-beta-cellobioside with chromic acid and saponification of the product gave 8. The synthesis of 20 involved glycosylation of methyl 5-O-acetyl-1,2-O-isopropylidene-alpha-D-glucofuranuronate or its 3-O-trityl derivative and subsequent furanose----pyranose transformation. The derivatives 8 and 20 were each copolymerised with acrylamide. In serological tests (enzyme immunoassay and passive hemagglutination), the resulting antigens exhibited the specificity of S3. It was concluded that fragment A was a much stronger immunodeterminant than fragment B. 相似文献
20.
Splettstoesser WD Rahalison L Grunow R Neubauer H Chanteau S 《FEMS immunology and medical microbiology》2004,41(2):149-155
Rapid detection of soluble F1 capsular antigen in serum, bubo fluid or urine of patients proved to be a valuable tool in the presumptive diagnosis of plague. We evaluated a F1 capsular antigen capture ELISA resembling a commercially available test kit. The minimal detectable concentration was 4 ng/ml. The specificity was 100% when investigating 47 sera from healthy Malagasy subjects and 98.4% when 365 sera from German blood donors were studied. Sensitivity was determined on sera (n=11) and buboes (n=18) from bacteriologically confirmed Malagasy plague patients. Sensitivity was 90.1% for serum and 100% for buboes. A standardized F1 capsular antigen capture ELISA test kit might be well suited for the early detection of plague particularly in non-endemic areas where clinical microbiological laboratories have only limited access to alternative techniques for rapid identification of Yersinia pestis. 相似文献