Diphtheria: characteristics of the pathogen and laboratory diagnostics (lecture).

The problem of diphtheria infection remains relevant, since the circulation of toxigenic strains of Corynebacterium diphtheriae persists in the body of bacterial carriers, despite ongoing vaccination. The lecture presents modern ideas about the properties of the pathogen, its pathogenicity factors (toxin, pili, surface proteins (67-72P (or DIP0733), DIP1281, etc.) and their role in the pathogenesis of the disease.. Information about the clinical and epidemiological characteristics and modern methods of laboratory diagnostics of diphtheria is presented. The algorithm of bacteriological research and methods for determining the toxigenic properties of the pathogen are described. The basics of diphtheria vaccination as the only effective means of preventing mass outbreaks of this disease are considered in the framework of the proposed lecture. Knowledge of the peculiarities of the circulation of strains of Corynebacterium diphtheria in modern conditions, pathogenetic and clinical-epidemiological features of diphtheria, as well as modern methods of laboratory diagnostics is important and necessary for students of medical schools and infectious diseases doctors, pediatricians, bacteriologists, therapists, pulmonologists, epidemiologists, etc.

[Cypopathic effect of diphtheria pathogen in the composition of biofilm.]

When the nasopharynx is colonized with toxigenic strains of the diphtheria pathogen, toxin is released, which contributes to the death of epithelial cells. But in bacterial carriers, the development of the clinical picture of the disease does not occur. This is due to the peculiarities of the state of their immune system, as well as the peculiarities of the production of diphtheria exotoxin by corynebacteria in the biofilm. Goal. Determining the nature of the cytopathic effect of C. diphtheriae as part of a biofilm in CHO-K1 cell culture. The planktonic and biofilm (120- and 720-hour) cultures of the strains were studied: C. diphtheriae gravis tox+ № 665, C. diphtheriae gravis tox+ № 6765, C. diphtheriae mitis tox+ № 269, C. diphtheriae gravis tox+ isolated from a patient with a diagnosis Localized oropharyngeal diphtheria C. diphtheriae gravis with a silent tox-gene. Biofilm (120- and 720-hour) cultures of diphtheria pathogen strains were obtained according to the Watnik method. The cytopathic effect of corynebacterial strains was studied on a CHO-K1 cell culture, taking into account in an inverted microscope. When studying the cytopathic effect of planktonic cultures of toxigenic strains of corynebacteria, it was found that the number of living CHO-K1 cells after 24 hours was insignificant (25.3±1.2%) and sharply decreased (2.5±0.5%) after 72 hours of cultivation. Under the influence of biofilm and, especially, 720-hour cultures, a different cytopathic effect dynamics was found: the number of living cells after 24 hours remained significant (82.5±2.2%), while at 72-hour it decreased to 25.0±3.0%. In the study of filtrates of planktonic and biofilm cultures of C. diphtheriae strain with a «silent¼ tox-gene, similar patterns were revealed. However, the number of live CHO-K1 cells when exposed to the filtrate of a 720-hour biofilm culture was significantly higher (p≤0.05) than when studying toxigenic strains of corynebacteria. Considering the nature of the cytopathic action, it was found that planktonic cultures of toxigenic strains of corynebacteria are characterized by a change in the cell monolayer, manifested by their thinning and elongation. The study of 720-hour biofilm cultures at 72-hour exposure revealed the appearance of a large number of rounded cells (63-69%). The cytopathic effect, formed under the influence of filtrates of planktonic and biofilm cultures of C. diphtheriae with a «silent¼ tox-gene, as well as strains of non-diphtheria corynebacteria, is characterized by rounding of cells and the formation of symplasts. In the biofilm, the intensity of the cytopathic effect of toxigenic C. diphtheriae strains and C. diphtheriae strain with a silent tox-gene decreased. CPD, manifested by thinning and lengthening of CHO-K1 cells, is associated with the action of diphtheria exotoxin, and rounding is associated with corynebacterial enzymes and, apparently, fragments of surface structures - adhesins. Decreased release of toxin and enzymes beyond the C. bihfilm matrix is a significant cause of the «asymptomatic¼ carriage of diphtheria.

[Analysis of the frequency of allocation of Corynebacteria non-diphtheria from patients with inflammatory diseases of the respiratory tract.]

Corynebacteria non-diphtheria and, in particular, C. pseudodiphtheriticum species that are closely related to C. propinquum and C. striatum form a group of new respiratory pathogens leading to the development of bronchitis, tracheitis, exacerbation of chronic obstructive pulmonary diseases, nosocomial pneumonia and other pathology. The goal is to analyze the frequency of the release of Сorynebacteria non-diphtheria from the upper respiratory tract of patients with various inflammatory diseases of the respiratory tract. Strains of Сorynebacteria non-diphtheria (C. pseudodiphtheriticum, C. propinquum, C. accolens, et al.), isolated from patients with inflammatory diseases of the respiratory tract (60 pcs.) and practically healthy individuals (31 pcs.) were studied. Identification of Сorynebacteria was performed using the method of mass spectrometry (MALDI-ToFMS). Сorynebacteria nondiphtheria in the amount of 105 and higher were more frequently detected with the development of chronic tonsillitis (60.0%) and nasopharyngitis (30%). The strains of C. pseudodiphtheriticum (40.0±6.4%) and the closely related species C. propinquum (21.7±5.3%) were mainly found; much less often - C. accolens (8.3±3.6%), C. afermentans (6.7±3.3%), et al. In 86.7% of cases, Corynebacteria non-diphtheria were isolated from children. In chronic tonsillitis, C. pseudodiphtheriticum and the closely related species of C. propinquum were isolated more often; in nasopharyngitis and bronchitis - С. pseudodiphtheriticum. Isolation of Corynebacteria non-diphtheria and, especially, C. pseudodiphtheriticum, C. propinquum, C. accolens species from patients with inflammatory diseases of the respiratory tract in the amount of 105 and above, if there are no other pathogenic microorganisms in the role of microbial associates, of clinical importance.

[Sensitivity and resistance to antimicrobial agents ESBL-producing and not producing ESBL strains of E. coli in patients with urinary tract infection.]

As a result of the conducted researches it is shown that 44.1% of urinary tract infections (UTIS) caused by E. coli are accounted for by producers of beta-lactamase of the extended spectrum of action (ESBL). Associated resistance to fluoroquinolones and co-trimoxazole was found in 93.3% of BLRS-producing E. coli strains. All studied strains regardless of ESBL production were sensitive to imipenem, the majority showed sensitivity to ertapenem, gentamicin and resistance to doxycycline. Not producing ESBL strains of E. coli were sensitive to fosfomycin. Comparison of data obtained during testing of isolated cultures on ESBL, study of their sensitivity and resistance to beta-lactams (amoxicillin/clavulanate, ceftazidime, ceftriaxone, cefotaxime, imipenem) indicates the need to test isolates for AmpC products. To this end, during the screening test for ESBL and the method of «double disks¼, along with cephalosporins of III generation, it is necessary to use a phenotypic test for sensitivity to cefepime. The use of test results of E. coli isolates isolated from patients with UTIS for the production of ESBL, ampC enzymes, carbapenemase and sensitivity to AMP will improve the effectiveness of antimicrobial therapy and will help to curb the formation and spread of antimicrobial-resistan strains.

[The antibiotic sensitivity of Corynebacterium diphtheriaе gravis tox+ in composition of mixed biofilms.]

The purpose of study is to determine sensibility of strains of C. diphtheriae gravis tox+ in the composition of mixed biofilms to antibacterial medications. The object of study was strains of Corynebacterium diphtheriae gravis tox+ № 665, Corynebacterium pseudodiphtheriticum (poly-resistant), Corynebacterium pseudodiphtheriticum (antibiotic-resistant). Two mixed biofilms (120- and 720-hours) of strain of Corynebacterium diphtheriae gravis tox+ № 665 with strains of Corynebacterium pseudodiphtheriticum (poly-resistant), Corynebacterium pseudodiphtheriticum (antibiotic-resistant) were formed. The sensibility of typical and biofilm cultures of Corynebacteria to antibiotic medications was established using technique of serial dilution in fluid growth medium on the basis of MPC (mg/l). The typical culture of museum strain C. diphtheriae gravis tox+ № 665, modeling mixed biofilms had a sensitivity to all used antibacterial medications. The analysis of antibiotic resistance of strain of C. diphtheriae gravis tox+ № 665 in content of biofilm with strain С. pseudodiphtheriticum, poly-resistant to four antibacterial medications (cefazolin, kanamycin, azithromycin, ciprofloxacin, IPC from 1.25±0,00 to >5±0,00 mkg/ml) set reduction (p≤0,05) sensitivity 120-hour biofilm cultures of this strain to cefazolin, azithromycin, ciprofloxacin (MIC of 0, 234 and up to ±0,11>5±0,00 ug / ml) established decreasing (p≤0,05) of sensitivity of 120-hours biofilm culture of this strain to cefazolin, azithromycin, ciprofloxacin (MIC from 0, 234±0,11 to >5±0,00 mkg/ml) and 720-hours culture - to all mentioned medications (MIC from 0,312±0,00 to >5±0,00 mkg/ml). The comparison of antibiotics resistance of biofilm cultures of strain C. diphtheriae gravis tox+ № 665 established that indices of MIC of most of antibacterial medications and especially to those that poly-resistant and forming biofilm strain С. рseudodiphtheriticum was resistant, were higher as related to biofilm cultures of diphtheritic bacteria separated from biofilm with antibiotic resistant strain С. рseudodiphtheriticum. The trend was established related to decreasing of antibiotic sensitivity of Corynebacteria at cultivation in content of mixed biofilms with representatives of opportunistic Corynebacteria having polyresistance to antibacterial medications.

[CORYNEBACTERIUM: FEATURES OF THE STRUCTURE OF THE BACTERIAL CELL].

In a review of the features of the bacterial cells are Corynebacterium structure: characterized by an upper layer, highly organized cell wall, cytoplasmic membrane, cytoplasm, nucleoid. Described in detail the structure of the upper layer containing pili (fimbriae), microcapsule surface proteins - PS-2, DIP1281, 67-72r protein (hemagglutinin), porins, sialidase (neuraminidase). These components are the ability to initiate a serial of Corynebacterium work with the host cell, followed by colonization. It submitted a detailed description .of the structure and functions of cell wall structures - cord factor, which is a second barrier permeability; arabinogalactan, peptidoglycan, lipomannan and lipoarabinomannan. The structure and function of the cytoplasmic membrane as the main diffusion barrier cell cytoplasm and the genome of Corynebacterium. Presented differ- ent molecular genetic methods for the identification and differentiation of closely related species of Corynebacterium.

[ANTIBIOTICS RESISTANCE OF CORYNEBACTERIUM NON DIPHTHERIAE STRAINS].

AIM: Study the frequency of occurrence of antibiotics resistant strains of various species of Corynebacterium non diptheriae. MATERIALS AND METHODS: C.pseudodiphtheriticum, C.pseudo- tuberculosis, C.xerosis, C.amycolatum, C.striatum, C. ulcerans strains isolated from patients with pathologies of respiratory and urogenital tract, as well as individuals taking prophylaxis ex- amination were used. Sensitivity to antibacterial preparations was determined by the serial dilution method. RESULTS: The highest number of Coryniebacterium non diptheriae strains dis- played resistance to benzylpenicillin (54.8%) and lincomycin (50.7%), and lowest - to cefotaxime, cefazolin (6.8%) and vancomycin (13.7%). The highest number of antibiotics resistant strains were detected among members of C.pseudotuberculosis (100%), C.xerosis (96.0%) and C. pseudodiphtheriticum (81.0%) species. Polyresistant strains were detected most frequently among C.xerosis, C.amycolatum and C.striatum species. Strains of Corynebacterium non diptheriae most frequently displayed resistance to 1 or 2 antibacterial preparations (24.7%), less frequently - to 3 (20.5%); 4 (13.7%), 5 (4.1%) and 6 (1.4%) preparations. CONCLUSION: The amount of antibiotics resistant strains of Cdrynebacterium non diptheriae is large (89.0%) and non-similar in various species.

[The sensitivity to antibiotics of Corynebacterium non diphtheriae isolated in hospitals of Rostov-on-Don and the Rostovskaia oblast.]

The purpose of study is to analyze sensitivity of various species Corynebacterium non diphtheriaе to antibacterial pharmaceuticals. The strains of C. non diphtheriae are separated from patients with pathology of respiratory and urogenital tract and also from individuals subjected to preventive examination. The sensitivity to antibacterial pharmaceuticals was determined using technique of serial dilution in fluid growth medium on the basis values of minimal inhibitory concentration (mg per l). It is established that the most efficient antibacterial pharmaceuticals in the case of strains C. non diphtheriae proved to be Vancomycin, Cefazolin and Cefotaxime in general. In case of such particular species as С. pseudodiphtheriticum -- Cefazolin, Cefotaxime and Gentamycin; С.pseudotuberculosis -- Vancomycin, Cefazolin, Cefotaxime and Gentamycin; C. xerosis -- Cefotaxime; С.striatum -- Cefazolin and и Rifampicin. The least efficiency was manifested for strains C. non diphtheriae by Benzylpenicillin and Lincomycin in general. In case of such particular species as С. pseudodiphtheriticum and С. pseudotuberculosis -- Lincomycin and Erythromycin; C. xerosis and С. striatum -- Benzylpenicillin, Lincomycin and Erythromycin. In case of various species of C. non diphtheriae Сephalosporins (Cefotaxime and Cefazolin) can be recommended as pharmaceuticals of choice and Gentamycin and Vancomycin as reserve pharmaceuticals.

[Corynebacterium riegelii as an unusual species separated from female patient with tuberculosis.]

The article describes a clinical case of tuberculosis of of urinary tracts of a female patient with massive discharge of strain Corynebacterium riegelii from urogenital tract. The data of clinical laboratory examination of female patient are analyzed. The characteristics of isolated strain C. riegelii (high degree of isolation rate (106 and higher) expressed urease activity (decomposition of urease during 5 min), presence of hemolytic activity) with consideration for estimation of its antibiotics sensitivity. The etiologic significance of isolated species C. riegelii in development of infection process in urogenital tract is demonstrated.

[The methods of identification of Corynebacterium non diphtheria].

The proper identification of Corynebacterium non diphtheriae is complicated by their wide species variety, variable biochemical activity, large spectrum of diseases at which they are isolated and also by their presence in normal human micro-flora. The bacteriological method is a traditional basis for identification of corynebacteria though long (7-14 days), produces ambiguous results at cultivation of lipophilic and biochemically variable species. For final identification of nondescript species of Corynebacterium non diphtheriae it is recommended to carry out molecular genetic study using golden standard - sequencing on 16S pRNA (DNA), genes rpoB and PLD.In case of receiving of ambiguous responses of sequencing on 16S pRNA precise identification is achieved by sequencing of secondary gene rpoB that permits discovering unique differences in sequences of genomes in different species of corynebacteria (presence of genes of virulence; absence of cluster of genes responsible for production of number of saccharolytic enzymes; presence of genes coding synthesis of particular pigments, etc.). The mass-spectrometric analysis (MALDI-ToF-MS) applied for screening identification of Corynebacterium, is simple in implementation, though requires further development for more accurate differentiation of closely-related species. The poly-phase approach to identification of Corynebacterium non diphtheriae is needed which is to include chemotaxonomic, phenotypic, genotypic information required for reliable description of new clinically significant species of corynebacteria.

[PATHOGENICITY FACTORS OF CORYNEBACTERIUM NON DIPHTHERIAE].

Pathogenicity factors of Corynebacterium non diphtheriae - pili, microcapsule, cell wall, pathogenicity enzymes, toxins, that determine the ability of microorganisms to consequentially interact with epithelium of entry gates of the organism, replicate in vivo, overcome cell and hu- moral mechanisms of protection, are examined in the review. Particular attention in the paper is given to species of non-diphtheria corynebacteria, that are pathogenic for human and able to produce toxins - Corynebacterium ulcerans and Corynebacterium pseudotuberculosis. Mechanisms of expression regulation of PLD-exotoxins, its interaction with immune system cells are described.

[Features of biofilm morphology, formed by Corynebacterium diphtheriae gravis tox+ strains].

AIM: Study the structure of homogenous microbial communities of Corynebacterium diphtheriae gravis tox+ strains during formation of biofilms in vitro. MATERIALS AND METHODS: Object of study--typical and biofilm cultures of C. diphtheriae gravis tox+ museum and circulating strains. Intensity of biofilm formation was evaluated by OD on microplate reader at 540 nm wave length studying 120 and 720 hour cultures. S-450 (Hitachi, Japan) scanning electron microscope was used. RESULTS: The peak of exopolysaccharide matrix (EPS) formation, that is formed in the process of biofilm formation, by museum strain takes place at earlier terms of cultivation (120 hours) than circulating (720 hours). An inverse correlation was established during analysis of bacterial cells of museum and circulating strains of C. diphtheriae during biofilm formation between them and intensity of EPS formation. At maximum EPS content, that took place at various terms of cultivation of the 2 studied strains of diphtheria causative agent, a reduction of corynebacteria cells was observed. CONCLUSION: Bacterial biofilms of museum and circulating strains of C. diphtheriae and patterns of dynamics of EPS reflect, probably, adaptive abilities of the causative agent, that determine its competitiveness in the fight for adhesion sites, resistance to factors of natural immunity and as a result--prolonged persistence in the organism of bacterial carriers.

[THE DIAGNOSTIC APPROACHES TO VERIFICATION OF STREPTOCOCCUS INFECTION IN PATIENTS WITH INFECTIOUS MONONUCLEOSIS].

The Rostovskii state medical university of Minzdrav of Russia, 344022 Rostov-on-Don, Russia The analysis is applied concerning significance of laboratory techniques of verification of streptococcus infection (bacteriological analysis, detection of anti-streptolysin O in pair serums) in 148 patients with infectious mononucleosis aged from 3 to 15 years. The content of anti-streptolysin O exceeded standard in 41 ± 4.8% of patients with concomitant in acute period and in 49.5 ± 4.9% during period of re-convalescence. This data differed from analogous indicator in patients with negative result of examination on streptococcus infection independently of period of disease (9.3 ± 2.8%). The exceeding of standard of anti-streptolysin O was detected more frequently (t ≥ 2, P ≥ 95%) in patients with isolation of Streptococcus pyogenes (56.9 ± 5.8%) than in patients with Streptococcus viridans (31.2 ± 6.5%). The concentration of anti-streptolysin 0 in patients with concomitant streptococcus infection varied within limits 200-1800 IE/ml. The minimal level of anti-streptolysin O (C = 200 IE/mI) was detected independently of type of isolated Streptococcus and period of disease. The high levels of anti-streptolysin O were observed exclusively in patients with isolation of Streptococcus pyogenes. In blood serum ofpatient with concomitant streptococcus infection (Streptococcus pyogenes + Streptococcus viridans) increasing of level of anti-streptolysin O was detected in dynamics of diseases from minimal (C = 200 IE/ ml) to moderately high (200 < C < 400 IE/mI). It is demonstrated that to identify streptococcus infection in patients with infectious mononucleosis the anamnesis data is to be considered. The complex bacteriological and serological examination ofpatients is to be implemented This is necessary for early detection ofpatients with streptococcus infection and decreasing risk of formation of streptococcus carrier state.

[THE COMPARATIVE ANALYSIS OF TECHNIQUES OF IDENTIFICATION OF CORYNEBACTERIUM NON DIPHTHERIAE].

The comparative analysis was carried out concerning effectiveness of three techniques of identification of Corynebacterium non diphtheriae: bacteriological, molecular genetic (sequenation on 16SpRNA) andmass-spectrometric (MALDI-ToFMS). The analysis covered 49 strains of Corynebacterium non diphtheriae (C.pseudodiphheriticum, C.amycolatum, C.propinquum, C.falsenii) and 2 strains of Corynebacterium diphtheriae isolated under various pathology form urogenital tract and upper respiratory ways. The corinbacteria were identified using bacteriologic technique, sequenation on 16SpRNA and mass-spectrometric technique (MALDIToF MS). The full concordance of results of species' identification was marked in 26 (51%) of strains of Corynebacterium non diphtheriae at using three analysis techniques; in 43 (84.3%) strains--at comparison of bacteriologic technique with sequenation on 16S pRNA and in 29 (57%)--at mass-spectrometric analysis and sequenation on 16S pRNA. The bacteriologic technique is effective for identification of Corynebacterium diphtheriae. The precise establishment of species belonging of corynebacteria with variable biochemical characteristics the molecular genetic technique of analysis is to be applied. The mass-spectrometric technique (MALDI-ToF MS) requires further renewal of data bases for identifying larger spectrum of representatives of genus Corynebacterium.

[Adhesion of corynebacterium diphtheriae: the role of surface structures and formation mechanism].

The paper is devoted to the study of surface structures including pili (fimbriae) 67-72p surface protein, DIP 1281 surface protein, lipoarabinomannan CdiLAM and their role in the adhesion and colonization of the mucous membrane of the throat by Corynebacterium diphtheriae. A description is offered for the main stages in the adhesion process of diphtheria causative agent and the ability of its adhesins to stimulate the effect of innate and acquired immunity factors. The paper stresses prospectiveness of the development of vaccines forming immunoprotection of the organism against adhesive activity of C. diphtheriae and also preventing their colonization and reproduction. That would facilitate a solution for the problem of diphtheria carrier state, which cannot be solved using the existing means of preventive vaccination.

[Mechanisms of formation of post-vaccinal immune response in children immunized with APDT and ADT-M preparations].

AIM: Study the mechanisms of formation of cell and humoral immunity against pertussis, diphtheria and tetanus in children immunized with immunobiological preparations (APDT vaccine and ADT anatoxin). MATERIALS AND METHODS: 30 practically healthy children (6 - 9 years of age) immunized with APDT and ADT-M preparations had TLR2, TLR4 expression determined in mononuclear cells (MNC). Vaccine preparations (APDT, ADT-M, AD-M, AT) and Corynebacterium diphtheriae gravis tox+, C. diphtheriae mitis tox- and Bordetella pertussis 345 were used as ligands. Cytokine production was determined in EIA. Content of anti-diphtheria, anti-tetanus and anti-pertussis antibodies--by PHA reaction and EIA. RESULTS: During stimulation with vaccines and B. pertussis 345 strain MNC were characterized by an increase (p < 0.05) of expression level of TLR2 and TLR4 and did not respond to stimulation with C. diphtheriae gravis tox+ and C. diphtheriae mitis tox- strains. Similar results were obtained during study of cytokine production (TNFalpha, IL-1, IL-6). A direct correlation between levels of antitoxic antibodies against diphtheria and tetanus (R = 0.486), antibacterial antibodies against pertussis and diphtheria was detected (R = 0.529). CONCLUSION: Analysis of cytokine production profile and determination of surface TLR expression can be used during evaluation of functional status of innate immunity cells and intensity of post-vaccinal immunity.

[The comparative characteristic of immune status of males with bacterial inflammatory urogenital pathology of different etiology in the city of Orenburg].

The article discusses presence of typical characteristics of parameters of system immunity under gonococcal and nonspecific uretroprostatitis and diagnostic value of these indicators. The reliable differences of immunologic indicators in patients with gonorrhea are established as compared to patients with nonspecific bacterial uretroprostatitis. The study established in peripheral blood the reliable decrease of level of leukocytes, relative amount of monocytes, phagocyte index, functional reserve of leukocytes at the expense of spontaneous and stimulated NBT test, IgA, sIgA. On the contrary, the study detected increasing of level of IgM and lactoferrin in patients with gonorrhea as compared to corresponding indicators in patients nonspecific infections. Under gonorrhea, the largest deviation of indicators from standard values was established for lactoferrin. The detected differences of immunologic parameters can be used as differentiating markers of nonspecific and gonococcal uretroprostatitis and criteria of effectiveness of immune correction.

[Apoptogenic activity of microbes-associants during Epstein-Barr virus infection].

AIM: Study apoptogenic activity of-microbes-associants during Epstein-Barr virus infection (EBVI) on the model of mice peritoneal macrophages in vitro. MATERIALS AND METHODS: Evaluation of apoptosis induced by bacteria isolated from EBVI patients was carried out by characteristic morphological changes of macrophages in smears stained by May-Grunwald with additional staining by Romanowsky-Giemsa. RESULTS: All the EBVI microbes-associants were established to have apoptogenic activity, however, the highest pathogenic potential was noted in Streptococcus pyogenes. CONCLUSION: The presence of apoptogenic activity in bacterial microflora accompanying EBVI against immune system cells could serve as means of their survival and be the pathogenetic basis for prolonged persistence in the organism.

[Effect of Corynebacterium non diphtheriae on functional activity and apoptosis of macrophages].

AIM: Determine the ability of Corynebacterium non diphtheriae to induce phagocytosis and apoptosis of macrophages and evaluate regulatory effect of nuetrophilokines (NPK) induced by Corynebacterium non diphtheriae on these processes. MATERIALS AND METHODS: The ability of Corynebacterium non diphtheriae, isolated from upper respiratory tract, skin and urogenital tract (UGT) were studied for the ability to induce phagocytosis and apoptosis of mice macrophages (MP; in vitro during staining by May-Grunwald with additional staining by Romanowsky-Giemsa) before and after the addition of NPK induced by Corynebacterium non diphtheriae. RESULTS: Phagocytic index (PI) was the same for all the Corynebacterium non diphtheriae species, phagocytic number (PN) and index of phagocytosis completion (IPC)--were minimal relative to corynebacteria isolated from UGT. All the studied corynebacteria species induced MP apoptosis; the most pronounced apoptogenic effect was detected in Corynebacterium pseudotuberculosis isolated from UGT. NPK increased PN against corynebacteria isolated from the studied biotopes, IPC--only during studies of corynebacteria isolated from skin. The effect of NPK resulted in a reduction of apoptogenic effect for almost all the Corynebacterium non diphtheriae, regardless of the isolation location. CONCLUSION: A pronounced apoptogenic effect and insufficiency of phagocytosis processes induced by corynebacteria are the means of realization of Corynebacterium non diphtheriae pathogenic effect. NPK use is possible for immune correction of immune deficiency conditions developing against the background of diseases determined by Corynebacterium non diphtheriae.

[The ability of diphtheria causative agent to form biofilm].

The article deals with results of studying diphtheria causative agent capacities to form biofilm as one of mechanisms of persistence in human organism. The study object was strain of C.diphtheriae gravis tox+ obtained from nasopharynx of patient aged 19 in municipal hospital No 1 of town of Gukovo of Rostov oblast in 2011. The patient had diagnosis of "diphtheria of nasopharynx, typical filmy, localized, mild severity, even course". The control was implemented using the museum strain C.diphtheriae gravis tox+ No 665 from the L.A. Tarasevitch state research institute of standardization and biologic preparations control. It is established that diphtheria causative agent as an ability to form biofilm. The intensity of process of formation of exopolysaccharide is higher on glass that on plastic surfaces. The differences in degree of intensity of formation of biofilm are revealed between the strain circulation in population and museum strains C.diphtheriae gravis tox+. The vital capacity of biofilm forming microorganisms is related with adaptation possibilities of strains.