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1.
Infect Immun ; 87(10)2019 10.
Article in English | MEDLINE | ID: mdl-31308088

ABSTRACT

Acute otitis media is one of the most common childhood infections worldwide. Currently licensed vaccines against the common otopathogen Streptococcus pneumoniae target the bacterial capsular polysaccharide and confer no protection against nonencapsulated strains or capsular types outside vaccine coverage. Mucosal infections such as acute otitis media remain prevalent, even those caused by vaccine-covered serotypes. Here, we report that a protein-based vaccine, a fusion construct of epitopes of CbpA to pneumolysin toxoid, confers effective protection against pneumococcal acute otitis media for non-PCV-13 serotypes and enhances protection for PCV-13 serotypes when coadministered with PCV-13. Having cross-reactive epitopes, the fusion protein also induces potent antibody responses against nontypeable Haemophilus influenzae and S. pneumoniae, engendering protection against acute otitis media caused by emerging unencapsulated otopathogens. These data suggest that augmenting capsule-based vaccination with conserved, cross-reactive protein-based vaccines broadens and enhances protection against acute otitis media.


Subject(s)
Antibodies, Bacterial/biosynthesis , Haemophilus Infections/prevention & control , Haemophilus influenzae/immunology , Otitis Media/prevention & control , Pneumococcal Vaccines/biosynthesis , Recombinant Fusion Proteins/biosynthesis , Streptococcus pneumoniae/immunology , Acute Disease , Animals , Bacterial Proteins/biosynthesis , Bacterial Proteins/genetics , Cross Protection , Cross Reactions , Female , Gene Expression , Haemophilus Infections/immunology , Haemophilus Infections/microbiology , Haemophilus influenzae/drug effects , Haemophilus influenzae/pathogenicity , Humans , Immunogenicity, Vaccine , Mice , Mice, Inbred BALB C , Otitis Media/immunology , Otitis Media/microbiology , Pneumococcal Vaccines/administration & dosage , Pneumococcal Vaccines/genetics , Recombinant Fusion Proteins/administration & dosage , Recombinant Fusion Proteins/genetics , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/pathogenicity , Streptolysins/biosynthesis , Streptolysins/genetics , Toxoids/biosynthesis , Toxoids/genetics , Vaccination , Vaccines, Synthetic
2.
Biomed Res Int ; 2015: 584696, 2015.
Article in English | MEDLINE | ID: mdl-25705675

ABSTRACT

Bloom-forming freshwater cyanobacterial genera pose a major ecological problem due to their ability to produce toxins and other bioactive compounds, which can have important implications in illnesses of humans and livestock. Cyanobacteria such as Microcystis, Anabaena, Oscillatoria, Phormidium, and Aphanizomenon species producing microcystins and anatoxin-a have been predominantly documented from most South Korean lakes and reservoirs. With the increase in frequency of such blooms, various monitoring approaches, treatment processes, and prediction models have been developed in due course. In this paper we review the field studies and current knowledge on toxin producing cyanobacterial species and ecological variables that regulate toxin production and bloom formation in major rivers (Han, Geum, Nakdong, and Yeongsan) and reservoirs in South Korea. In addition, development of new, fast, and high-throughput techniques for effective monitoring is also discussed with cyanobacterial bloom advisory practices, current management strategies, and their implications in South Korean freshwater bodies.


Subject(s)
Cyanobacteria/growth & development , Ecology , Marine Toxins/biosynthesis , Water Microbiology , Cyanobacteria/metabolism , Cyanobacteria/pathogenicity , Eutrophication/physiology , Fresh Water/microbiology , Humans , Lakes , Marine Toxins/metabolism , Microcystins/biosynthesis , Microcystins/metabolism , Republic of Korea , Toxoids/biosynthesis , Toxoids/metabolism
3.
Anaerobe ; 18(3): 363-5, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22306065

ABSTRACT

In this work, we produced and evaluated a vaccine based on a ß toxoid of Clostridium perfringens type C produced in Escherichia coli (rBT). The non-toxic rBT was innocuous for mice and induced 14 IU mL(-1) of ß antitoxin in rabbits, complying with the European Pharmacopeia and CFR9 - USDA guidelines.


Subject(s)
Bacterial Vaccines/biosynthesis , Clostridium perfringens/immunology , Toxoids/biosynthesis , Vaccines, Synthetic/biosynthesis , Animals , Bacterial Toxins/genetics , Bacterial Vaccines/genetics , Bacterial Vaccines/toxicity , Escherichia coli , Mice , Mice, Inbred BALB C , Rabbits , Toxoids/genetics , Toxoids/toxicity , Vaccination , Vaccines, Synthetic/genetics , Vaccines, Synthetic/toxicity
4.
Bioprocess Biosyst Eng ; 35(3): 407-14, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21833619

ABSTRACT

The carboxylic domain of the Clostridium botulinum neurotoxin heavy chain (BoNT/A-HC), which has been reported as a vaccine candidate, contains the principle protective antigenic determinants. In this study, the high level expression of the BoNT/A-Hc was achieved by high cell density cultivation of recombinant Escherichia coli in a 2-l batch stirred-tank bioreactor. In order to maximize protein expression, post-induction time and IPTG inducer concentration were optimized by the Taguchi statistical design method. Results showed that the middle of the logarithmic phase and an IPTG concentration of 1 mM presented the optimum conditions for the maximum expression of BoNT/A-HC. High cell density cultivation was subsequently carried out as an effective strategy for the high level expression of recombinant BoNT/A-Hc. Consequently, soluble BoNT/A-Hc was produced at the maximum level of 486 mg l(-1), at 3 h post-induction, which was approximately 9.3 and 7.8 times higher than the levels produced by the shake flask and batch culturing methods, respectively.


Subject(s)
Bioreactors , Botulinum Toxins, Type A/biosynthesis , Escherichia coli/growth & development , Recombinant Proteins/biosynthesis , Botulinum Toxins, Type A/genetics , Clostridium botulinum/enzymology , Clostridium botulinum/genetics , Escherichia coli/enzymology , Escherichia coli/genetics , Recombinant Proteins/genetics , Toxoids/biosynthesis , Toxoids/genetics
5.
Article in Russian | MEDLINE | ID: mdl-15773401

ABSTRACT

The comparative study of 4 constructed protective antigen producing strains of the classical biovar and V. cholerae strains 569 B Inaba and M41 Ogawa, used in manufacturing the cholera chemical vaccine "cholerogen-toxoid", was carried out. The study revealed that V. cholerae plasmid strains 2414 Ogawa, 2415 Inaba and nonplasmid strains 2416 Ogawa, 2417 Inaba had a higher level of production of the main protective antrigens in comparison with producer strains. They also synthesized much more (4-5 fold) cholera toxin, toxin co-regulated adhesion pili, contained protein OmpU in their outer membrane, exceeded 2- to 3-fold in the synthesis of pathogenicity enzymes (proteases, phospholipases) and synthesized the same amounts of 01 antigen, serovars Inaba and Ogawa. The use of the newly created protective-antigen producing strains in vaccine manufacturing could facilitate the preparation of a more effective cholera chemical vaccine "cholerogen-toxoid".


Subject(s)
Antigens, Bacterial/biosynthesis , Cholera Vaccines/immunology , Vibrio cholerae/immunology , Adhesins, Bacterial/biosynthesis , Bacterial Adhesion/immunology , Bacterial Outer Membrane Proteins/biosynthesis , Cholera Toxin/biosynthesis , Fimbriae, Bacterial/immunology , Peptide Hydrolases/biosynthesis , Phospholipases/biosynthesis , Plasmids , Recombinant Proteins/biosynthesis , Toxoids/biosynthesis , Vaccines, Synthetic/biosynthesis , Vaccines, Synthetic/immunology , Vibrio cholerae/enzymology , Vibrio cholerae/genetics
6.
Res Microbiol ; 152(6): 563-7, 2001.
Article in English | MEDLINE | ID: mdl-11501674

ABSTRACT

Fragments of Clostridium botulinum neurotoxin A (BoNT/A) gene (botA) were expressed in Listeria monocytogenes ATCC10527 to produce the L-chain of the toxin in a soluble form. A shuttle vector pAT19 (EmR) was used to make plasmid pAT-RL containing a botA gene fragment placed under C. botulinum ntnH-gene promoter control. The plasmid also contained a C. botulinum botR/A gene, a positive transcriptional regulator of botA. The cytoplasmic fraction of the L. monocytogenes (pAT-RL) strain was found to contain up to 3 mg/L of a soluble protein of expected size and immunologically positive towards BoNT antibodies. This is the first evidence of heterologous botA gene expression producing a soluble safe derivative of botulinum neurotoxin A needed as a molecular tool for exploratory research in neurosciences as well as a basis for raising protective immunity in humans.


Subject(s)
Botulinum Toxins, Type A/biosynthesis , Clostridium botulinum/genetics , Listeria monocytogenes/genetics , Animals , Antibodies, Bacterial/blood , Botulinum Toxins, Type A/chemistry , Botulinum Toxins, Type A/genetics , Clostridium botulinum/chemistry , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Bacterial/isolation & purification , Electrophoresis, Polyacrylamide Gel , Escherichia coli/chemistry , Escherichia coli/genetics , Listeria monocytogenes/chemistry , Listeria monocytogenes/metabolism , Peptide Fragments/biosynthesis , Peptide Fragments/chemistry , Peptide Fragments/genetics , Plasmids/chemistry , Plasmids/genetics , Polymerase Chain Reaction , Rabbits , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Toxoids/biosynthesis , Transformation, Bacterial/genetics
7.
Article in Russian | MEDLINE | ID: mdl-9662794

ABSTRACT

The dynamics of ultrafiltration was found to depend on the composition of the nutrient medium in which C.perfringens toxin accumulated. A new composition of casein-pancreatic medium with the reduced content of high-molecular peptides ensuring a high effect of membrane separation was developed. The influence of the main factors (pressure, concentration, the number of diafiltration cycles) on the characteristics of the membrane separation of type A C.perfringens culture. The optimum conditions for the purification of C.perfringens toxin by ultrafiltration were established with due regard to the data obtained in this investigation. Toxin concentrates were found to contain a fraction inhibiting their sorption capacity, and the method of the elimination of the inhibiting component was developed. C.perfringens toxoids, considerably exceeding commercial preparations in specific activity and immunogenic potency, were obtained.


Subject(s)
Biotechnology , Cell Separation/methods , Clostridium perfringens/immunology , Gangrene/prevention & control , Membranes, Artificial , Toxoids/biosynthesis , Chromatography, Gel , Pressure , Ultrafiltration
8.
Article in Russian | MEDLINE | ID: mdl-9662791

ABSTRACT

The reactor technology for obtaining suspensions of Staphylococcus aureus (strain Cowan 1) with active protein A was developed. On the basis of the sensitization of bacterial suspensions with antitoxic rabbit sera staphylococcal reagents to diphtherial, gas gangrene (perfringens, oedematiens), botulinic toxins-toxoids were obtained and for the first time the coagglutination test with toxoids was carried out. More sensitive "specifically directed" reagents for the coagglutination test were obtained; for this purpose bacterial suspensions were sensitized with pure antibodies isolated from rabbit immune sera by immunosorption. The possibility of using the coagglutination test with specifically directed staphylococcal reagents for the rapid evaluation of the dynamics of toxin formation in reactors for the titration of purified toxoids, for the control of the purification of toxoids by ultrafiltration, as well as for the evaluation of the sorption-desorption of toxoids in the production of the corresponding preparations, was shown.


Subject(s)
Agglutination Tests , Staphylococcal Protein A/immunology , Toxoids/biosynthesis , Animals , Botulinum Antitoxin/immunology , Diphtheria Toxoid/immunology , Gangrene/immunology , Immune Sera , Rabbits , Sensitivity and Specificity
10.
Appl Microbiol Biotechnol ; 48(2): 155-61, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9299772

ABSTRACT

Bioreactor selection is important for maximising the productivity of recombinant organisms. In this paper a comparison is made between growth and recombinant protein synthesis in three types of bioreactor containing a marine Vibrio capable of heterologous expression and secretion of the non-toxic B-subunit pentamer of Escherichia coli heat-labile enterotoxin, EtxB. The heterologous gene was located on the plasmid pMMB68. Resistance to carbenicillin was used to select for plasmid-containing cells. In batch and continuous culture. Volumetric productivities were highest when cells were grown in the presence of carbenicillin. Without antibiotic selection, the highest volumetric productivity (9.4 mg EtxB-1 h-1) was observed in hollow-fibre bioreactors, and the production phase could be maintained for over 50 h. The highest specific productivity under these conditions was found in batch culture, but the maximal production phase was only of 5 h duration. In hollow-fibre reactors the type of fibre used significantly affected productivity, both with regards to the maintenance of reactor integrity and by allowing passage of the recombinant toxoid through the selectively permeable membrane. Where contamination of the product with carbenicillin is to be avoided, these bioreactors are superior to batch or continuous culture.


Subject(s)
Bacterial Toxins/biosynthesis , Enterotoxins/biosynthesis , Escherichia coli Proteins , Escherichia coli/pathogenicity , Recombinant Proteins/biosynthesis , Toxoids/biosynthesis , Vibrio/metabolism
12.
J Bacteriol ; 148(3): 983-7, 1981 Dec.
Article in English | MEDLINE | ID: mdl-7031037

ABSTRACT

Recombinant deoxyribonucleic acid technology was employed to construct heat-labile enterotoxin (LT) toxoids. A recombinant plasmid carrying both an LT promoter region and LT subunit A (LTA) gene, lacking as much as 0.25 kilobases of the region up to the C terminus, produced a peptide possessing immunological properties of LTA but lacking the ability to construct LT activity (designated as LTA*). A cloned LT subunit B (LTB) gene produced LTB when a promoter on a vector was available for the gene. Escherichia coli producing LTA* and LTB (LT toxoids) could be useful as a vaccine.


Subject(s)
Bacterial Toxins , Enterotoxins/genetics , Escherichia coli Proteins , Escherichia coli/genetics , Genes, Bacterial , Toxoids/genetics , Cloning, Molecular , DNA, Recombinant , Enterotoxins/biosynthesis , Escherichia coli/metabolism , Plasmids , Toxoids/biosynthesis
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