Anti-adhesive therapies as a contemporary means to fight infectious diseases and adherence factors of Corynebacteria diphtheriae

The emergence and increasing prevalence of bacterial strains that cause infectious diseases and that are resistant to available antibiotics demand the discovery of new therapeutic strategies. For many pathogenic bacteria, infections are initiated only after the organism has first adhered to the host cell surface. A modern alternative approach to antimicrobial therapy is targeting bacterial virulence and specifically adhesion as one of virulence factors. This approach forms the basis of anti-adherence strategies, which have been devised to prevent a variety of bacterial infections. The article deals with some modern strategies for anti-adhesion therapy, the mechanisms of inhibition pathogen adherence, immunization using a bacterial adhesion, an adhesin subunit or an immunogenic peptide fragment and a DNA vaccine encoding the adhesin or part thereof and so on. Investigation of bacterial pili which orchestrate the colonization of host tissues is the area most in need of further study. Bacterial pili may be vaccine candidates in important human pathogens as being highly immunogenic structures which are under the selective pressure of host immune responses. C. diphtheriae, the causative agent of diphtheria, is well-investigated in respect to toxin production, while little is known about its factors crucial for colonization of the host. Adherence factors of Corynebacteria may be considered as probable components of developing of combined diphtheria vaccines with antibacterial action which localizes a diphtheritic infection in an organism. They’ll become an effective method against a resistant carrier state and be forward to stopping of pathogen circulation among human population

Анти-адгезивная стратегия в разработке комплексных противодифтерийных вакцин как перспективная мера снижения циркуляции Corynebacterium diphtheriae среди населения

A study is devoted to the development of new bacterial diphtheria vaccines aimed at prevention adhesion of microbial cells to host’s pharyngeal epithelial cells and thus limit colonization of mucous membranes, bacteria carrier state formation and promoted to C. diphtheriaе circulation decrease among the population. As a base of the candidate-vaccine we suggest the diphtheria bacterial antigenic preparation obtained by use of electro-magnetic radiation of ultrahigh frequency from a culture of C. diphtheriaе, var. gravis, tox +.Исследование посвящено разработке новых бактериальных дифтерийных вакцин, направленных на предупреждение колонизации слизистых оболочек, формирование бактерионосительства и способствующих снижению циркуляции C. diphtheriaе среди населения. В качестве основы кандидат-вакцины предлагается дифтерийный бактериальный антигенный препарат, полученный с помощью электро-магнитного излучения сверхвысокой частоты из культуры C. diphtheriaе, var. gravis, tox +

Anti-adhesive Strategy in Development of Combined Antidiphtheritic Vaccine as a Perspective Preventive Measure of Corynebacteria diphtheriae Circulation Among the Population

A study is devoted to the development of new bacterial diphtheria vaccines aimed at prevention adhesion of microbial cells to host’s pharyngeal epithelial cells and thus limit colonization of mucous membranes, bacteria carrier state formation and promoted to C. diphtheriaе circulation decrease among the population. As a base of the candidate-vaccine we suggest the diphtheria bacterial antigenic preparation obtained by use of electro-magnetic radiation of ultrahigh frequency from a culture of C. diphtheriaе, var. gravis, tox +

METHODS OF CONTROL DIPHTHERIA VACCINE SAFETY

Vaccination success depends not only on the timely coverage of threatened contingents, but also on the quality of vaccines. Every day, the requirements for security guarantees vaccines and their use guarantees of security increases. For the fast, reliable and independent scientific assessment of vaccine safety issues, WHO in 1999 created the Global Advisory Committee on Vaccine Safety. To enhance the capacity of pharmaceutical supervision in relation to vaccines in 2012 it was developed the Global Vaccine Safety Initiative. The main directions of the Global Vaccine Safety programs are considered in this review. It’s noted more strict requirements of Ukrainian pharmaceutical industry to produce public immunization drugs regulated Supplements to the State Pharmacopoeia of Ukraine, in comparison with other countries. This review considered diphtheria vaccine safety monitoring in the process of production according to the recommendations of the World Health Organization (WHO), described a subcutaneous method for determining the specific toxicity of the combined purified toxoid, characterized an intracutaneous method of determining of the presence of diphtheria toxin in each sample of the combined purified toxoid, that additionally used by some manufacturers. The definition of diphtheria toxin in dilutions of purified toxoid is presented. This review considered diphtheria vaccine safety monitoring in the process of production according to the recommendations of the World Health Organization (WHO), described a subcutaneous method for determining the specific toxicity of the combined purified toxoid, characterized an intracutaneous method of determining of the presence of diphtheria toxin in each sample of the combined purified toxoid, that additionally used by some manufacturers. The definition of diphtheria toxin in dilutions of purified toxoid is presented. As methods for determination of diphtheria toxin must be able to detect even a small amount of toxin it's examined the WHO's proposal to use an intradermal method on guinea pigs and tests on cell cultures. Attention is drawn to the fact that the determination of specific toxicity in cell culture can be carried out at presence of the approval of this method of a national control authority and sensitivity rates no less than in experiments on guinea pigs. The determining of specific toxicity of ready vaccine by subcutaneous method is described. The publication gave a test for elevated toxicity of the final product by intraperitoneal infection of mice and guinea pigs. It’s cited the WHO recommendations aimed at removing the possibility of recovery of the refined toxin toxicity. Checking vaccines toxicity, pyrogenicity, sterility, allergenicity, teratogenicity, mutagenicity and immunogenicity mainly performed on laboratory animals. The review examined the unreliability of animal experiments and the need to find alternative methods for determining the toxicity without their use particularly in light of the “3R”concept. Methods for determining diphtherial toxin using cell cultures is considered, namely, colony overlay test (COT), tests using a monolayer of HeLa cell culture, a culture of Vero cells (kidney cells of african green monkeys ), a culture of CHO cells (cells of Chinese hamster ovary), which are based on the toxin cytopathic effect on sensitive cell culture. Their advantages and disadvantages are listed. An alternative method for the quantitative detection of C. diphtheriae toxin using the polystyrene plate coated with monoclonal antibody to the part of the diphtheria toxin which defines its binding to the cell, is described. It’s regarded the cytotoxic effect of diphtheria toxin on cells of the immune system of mice and guinea pigs: splenocytes, adhesive phagocytes i B- lymphocytes

Анти-адгезивная стратегия в разработке комплексных противодифтерийных вакцин как перспективная мера снижения циркуляции Corynebacterium diphtheriae среди населения

A study is devoted to the development of new bacterial diphtheria vaccines aimed at prevention adhesion of microbial cells to host’s pharyngeal epithelial cells and thus limit colonization of mucous membranes, bacteria carrier state formation and promoted to C. diphtheriaе circulation decrease among the population. As a base of the candidate-vaccine we suggest the diphtheria bacterial antigenic preparation obtained by use of electro-magnetic radiation of ultrahigh frequency from a culture of C. diphtheriaе, var. gravis, tox +.Исследование посвящено разработке новых бактериальных дифтерийных вакцин, направленных на предупреждение колонизации слизистых оболочек, формирование бактерионосительства и способствующих снижению циркуляции C. diphtheriaе среди населения. В качестве основы кандидат-вакцины предлагается дифтерийный бактериальный антигенный препарат, полученный с помощью электро-магнитного излучения сверхвысокой частоты из культуры C. diphtheriaе, var. gravis, tox +.</p

Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L.

Two new aspartic proteinases have been isolated from stigmas of the cardoon Cynara cardunculus L. by a two-step purification procedure including extraction at low pH, gel filtration on Superdex 200, and ion-exchange chromatography on Mono Q. To follow the conventional nomenclature for aspartic proteinases, we have named these proteinases cardosin A and cardosin B. On SDS/PAGE, cardosin A migrated as two bands with apparent molecular masses of 31 000 Da and 15000 Da where as the chains of cardosin B migrated as bands of 34000 Da and 14000 Da. The partial amino acid sequences of the two cardosins revealed that they are similar but not identical, and that they differ horn the previously reported cardoon proteinases named cynarases, which were assumed to be derived from a common precursor. Although the cardosins show some degree of similarity to each other, we could detect no immunological cross-reactivity between them. Both cardosins were active at low pH and were inhibited by pepstatin, with Ki values of 3 nM for cardosin A and 1 nM for cardosin B, indicating that they belong to the class of aspartic proteinases. Significant differences between the two enzymes were also found for the Kcat/Km values for the hydrolysis of two chromophoric synthetic peptides. The active-site ionization constants, pKe1 and pKe2, for cardosin A are 2.5±0.2 and 5.3±20.2, whereas for cardosin R they are 3.73±10.09 and 6.7±50.1. The results herein described on the structural and kinetic properties of the cardosins indicate that they are the products of distinct genes which have probably arisen by gene duplication. A scheme for the proteolytic processing of the two enzymes is also proposed