Environmental Determination of Indigenous Bifidobacteria of the Human Intestine.

The environmental determination of indigenous (constantly present) bifidobacteria of the human large intestine is considered in this review. Environmental determination (from the Latin determinere, "I determine") is understood as a set of natural phenomena of a habitat (biotope) that determine the role of indigenous microorganisms in the microbiocenosis. Using the symbiotic approach, an attempt is made to identify the environmental conditions for the habitat of bifidobacteria and their physiological effects in the microsymbiocenosis. The features of indigenous bifidobacteria in terms of their nature have been established: evolutionary-genetic (phylogenetic remoteness, genome conservation, metabolic specialization), biochemical (lysozyme resistance, constitutive acetate production), and physiological (microbial "friend-foe" identification, immunoregulation), which are important in adaptation (persistence) and the provision of mutualistic effects and stability of the bifidoflora in the population.

Diagnostic cytokine marker of male infertility - interleukin 4.

Analysis of the study is to assess the diagnostic significance of cytokines in the sperm plasma of men of reproductive age (20 - 45 years) of two groups: of patients with chronic bacterial prostatitis, not complicated by infertility and with loss of fertility. The study of sperm plasma - the WHO standard. Determination of the level of cytokines in seminal plasma - by enzyme immunoassay («Cytokine¼, Russia). Two methods of mathematical statistics were used: discriminant analysis and classification trees (decision trees).The similarity of interpretations of discriminant analysis and decision tree was noted, where the main role in both cases belongs to the cytokine IL-4. The level of sperm IL-4 in combination with therapeutic monitoring can be used for the medical management of patients with chronic prostatitis in order to prevent the development of infertility and to develop methods for screening diagnostics of fertility disorders in men.

[Characterization of the microbiota and cytokine profile of sperm plasma in men with chronic bacterial prostatitis].

BACKGROUND: One of the leading causes of the occurrence of chronic bacterial prostatitis (CBP) in men is infection, microecological disorders of the urogenital tract and cytokine-mediated mechanisms of inflammation of the prostate gland, which actualizes a comprehensive study of the clinical and bacteriological features of CBP from the perspective of a symbiotic approach in the framework of a new scientific field - "infectious symbiology". OBJECTIVE: to study the characteristics of spermogram, microbiota, and the cytokine profile in men with chronic bacterial prostatitis (CBP) and CBP complicated by infertility. MATERIALS AND METHODS: A comprehensive study of patients with CBP and CBP complicated by infertility, in comparison with conditionally healthy individuals, was conducted. Species identification of microorganisms was carried out according to biochemical characteristics and the genetic method (sequencing of strains). The biological properties of the microbiota were evaluated: growth properties, biofilm formation, antipeptide activity against the cytokines IL-10, RAIL-1, TNF-, INF- and IL-17 (8 parameters). Immunological parameters of sperm plasma included 13 parameters: the content of cytokines TNF-, INF-, Rail, interleukins (IL) -1, 2, 4, 6, 8, 10, 17, immunoglobulin (Ig) A, lactoferrin and lysozyme. To evaluate sperm plasma, the following quantities were determined: ejaculate volume, pH, sperm plasma liquefaction, total sperm count, sperm count per 1 ml, motility, number of progressively motile, non-progressive motile and motionless spermatozoa, number of round cells, white blood cells, spermatogenesis cells, erythrocytes, erythrocytes, cells, sperm agglutination and aggregation (16 parameters in total). The results are statistically processed. RESULTS: Data were obtained on changes in biofilm formation, antipeptide activity of microbiota (especially pronounced in corynebacteria), sperm plasma cytokine profile (increased TNF , IL-2, 6, 17), as well as IgA and lactoferrin, which can be used to build a prognostic model of reproductive pathology tract of men and their fertile activity. CONCLUSION: The study of the antipeptide activity of microbiota in combination with the cytokine profile of ejaculate allows us to recommend them as a "biotarget" for diagnostic, preventive and therapeutic measures for chronic prostatitis in men, which contribute to solving the medical and social problem of preventing male infertility and contributes to the development of health-saving technologies with incorporating elements of personalized medicine.

Draft Genome Sequence of Klebsiella pneumoniae Strain ICIS-278_PBV, Isolated from the Feces of a Healthy 59-Year-Old Man from Orenburg, Russia.

This report describes the draft genome sequence of Klebsiella pneumoniae strain ICIS-278_PBV, isolated from the feces of a healthy 59-year-old man from Orenburg, Russia. The size of the genome was 5,584,615 bp (57.2% G+C content). Annotation revealed 5,302 coding sequences, including 5,254 proteins, 23 rRNA genes, and 81 tRNA genes.

[METABOLIC PROFILE OF BIFIDOFLORA UNDER DIFFERENT MICROECOLOGICAL CONDITIONS OF THE COLON BIOTOPE IN HUMAN].

AIM: To study the spectrum and level of short-chained fatty acids (SCFA) in supernatant of bifidobacteria under different microecological conditions ofthe colon biotope in human. MATERIALS AND METHODS: Metabolites of 88 bifidobacteria strains isolated from patients when examined for dysbiosis of the colon were investigated. Definition of concentration of SCFA was performed on acidified supernatant samples by a separation method on chromatograph GC-2010 Plus, Shimadzu (Japan). RESULTS: Monobasic acids were found in metabolites of 50 - 100% study cultures of bifidobacteria where the spectrum and level of carboxylic acids in supernatants varied depen- ding on microecological condition of the origin of the discharge. In severe damages of microsymbiocenosis in metabolites of Bifidobacterium spp., summarized concentrations of SCFA, structural index, levels of aceitic and propionic acids were decreased. Strain-specific differences in a metabolic profile of bifidofloia in a composition of individual consortiums were determined. Data obtained indicate the variation of functional (metabolic) activity of dominant strains in different microecological conditions of the human colon. CONCLUSION: Uniquieness of metabolome of every other strain due to their strain specifity determines their functional activity, but a metabolic profile of bifidoflora can serve as the most important criterion for the selection of effective probi- otic drugs for treatment and prevention of dysbioisis in the colon.

[GUT MICROSYMBIOCENOSIS IN CHILDREN WITH REACTIVE ARTHRITIS].

AIM: To study the state of gut microsymbiocenosis in children with reactive arthritis (RA), with the assessment of biofilm formation (BFF) of microsymbionts and the ability to change cytokine levels (their anticyokine activity) in vitro. MATERIALS AND METHODS: The investigation of gut microsymbiocenosis by means of bacteriological method was conducted in 34 children with RA and 25 relatively healthy 3 - 16 year- old children. Microorganisms were identified with the help of MALDI-TOF mass-spectrometry, anticytokine activity (ACA) of microsymbionts - according to Bukharin O.V et al. (2011), biofilm formation - according to O'Toole G.A., Kolter R. (1998). RESULTS: On the ground of species composition differences of gut microbiota discrimination model was created which allowed to separate the group of children with RA from healthy individuals. Microsymbiocenosis of patients with RA was characterized by increasing number of opportunistic microorganisms (OM) (enterobacteria, clostridia, bacteroides, and Candida), BFF and ACA level. CONCLUSION: The obtained data greatly contribute.to the deciphering of spondylo- arthritis and disclose the role of microbial factor under given pathology. Hypercolonisation of human gut with OM, having pronounced ability to BFF and regulating cytokine level, promotes strengthening of arthritogenic potential and serves as additional marker of arthritis development risk in children.

[INTERMICROBIAL <> DISCRIMINATION IN <> PAIR OF PROBIOTIC STRAINS OF ESCHERICHIA COLI M-17 AND E.COLI LEGM-18].

AIM: To use earlier developed method of intermicrobial <> discrimination in <> pair for the assessment of foreignness of probiotic cultures of Escherichia coli M-17 (with pathogenicity island) and E. coli LEGM-18, (without pathogenicity island). MATERIALS AND METHODS: As dominants reference and clinical strains of bifidobacteria were used in the work, cultures of E.coli M-17 and E. coli LEGM-18 were taken as associants, differing in the presence of genes which code colibactin. Detection of the phenomenon of microbial discrimination was conducted according to the developed algorithm (Bukharin O.V., Perunova N.B., 2011) based on the principle ofmetabolite induction as a result of preliminary coincubation ofdominants (bifidobacteria) with supernatant of associants and the formation of feed back in <> pair. Special growth properties, biofilm formation, and antilysozyme activity served as biological characteristics of investigated coliform bacteria. RESULTS: Testing of E. coli M-17 culture revealed depression of biological properties under investigation and it was estimated as <> possibly due to the presence of pathogenicity island whereas E. coli LEGM- 18 (without this frag- ment) sharply strengthened its biological characteristics and was subjected to assessment as <>. CONCLUSION: Use of intermicrobial <> pair is promising as basic method when selecting probiotic strains and cultures for creation of new sym- biotic compositions and is suitable for quality control of probiotic products.

[INFECTIOUS SYMBIOLOGY].

In the article new line of research--infectious symbiology that studies interaction of microsymbionts with the host in case of infection under the conditions of their biocommunicative interrelations is discussed. The presence of interrelation of intestinal microbiota with human homeostasis disorders postulates thesis that: human organism is superorganism including a lot of prokaryote species where microbiota normoflora representatives are the main complex of extra-corporeal physiological system acting as organism homeostasis regulator. When studying intermicrobial relations under microsymbiocenosis its system-forming factor has been identified that includes basic general functions of microorganisms--reproductive (growth/reproduction) and adaptive (biofilm formation and antilysozyme test). It has been shown that microbial interaction in dominant-associant vector providing microsymbiocenosis functioning is implemented via opposite (amplification/suppression) effect of reproductive and adaptive functions of microsymbionts of dominant-associant pair contributing self-non-self discrimination. Intermicrobial discrimination of self-non-self microsymbionts goes before signaling of adaptive immunity of the host promoting microbe elimination or persistence in the body depending on the result of identification. It has been noted that microbial factor fulfilling the role of organism homeostasis regulator performs synergistic functioning of dominant microflora with the host. When penetrating foreign associants (pathogens) into the organism host defense is implemented by means of induction of its adaptive immunity via cytokine reticulum. Key players of human intestinal microbiota are Bifidobacteria which along with induction of adaptive immunity and balance changes of pro- and anti-inflammatory cytokines of the host directly regulate microsymbiocenosis including system of hormones and neurotransmitters.

[REGULATING EFFECT OF ASSOCIATIVE MICROBIOTA ON THE RHYTHMS OF BIOLOGICAL PROPERTIES OF FUNGI AND BACTERIA].

AIM: Study the effect of exometabolites of associative microbiota on circadian dynamics of functional parameters, that reflect pathogenic and persistence properties of fungi and bacteria. MATERIALS AND METHODS: Clinical isolates of Candida albicans, isolated-from intestine of healthy individuals and patients with candidosis, as well as clinical isolates and museum ATCC strains Staphylococcus. aureus 25923, Escherichia coli 35218 and Pseudomonas aeruginosa 27853 were taken for study of proliferative, adhesive, catalase, protease, phospholipase, hemolytic, anti-lysozyme, biofilm-forming activity. The results were treated statistically. RESULTS: C. albicans isolates, isolated from healthy individuals were revealed to be indifferent to the effect of bacterial metabolites. Chrono-infrastructure of biological properties of fungi altered under the effect of microbiota metabolites. Hospital isolates of S. aureus, E. coli and P. aeruginosa displayed a relative stability of physiological properties against the effect of bacterial-fungal metabolites as opposed to museum strains. CONCLUSION: The alterations of chrono-infrastructure of biological rhythms of microorganisms by bacterial-fungal metabolites of associants reflect the intensity of the biological system, that is inevitable during the process of formation of inter-microbial interactions.

[INTRA-ERYTHROCYTE INVASION OF ESCHERICHIA COLI STRAINS WITH VARIOUS LEVELS OF ANTI-HEMOGLOBIN ACTIVITY IN EXPERIMENT].

AIM: Study of intra-erythrocyte invasion of Escherichia coli strains with various levels of anti-hemoglobin activity on a model of generalized infection. MATERIALS AND METHODS: Experiments were carried out on 72 male mice. Generalized infection was induced by intravenous administration of E. coli strain day culture suspension with various values of hemolytic and anti-hemoglobin activity. The levels of hemoglobin in animal blood was determined by hemoglobin-cyanide method. Intra-erythrocyte invasion of E.coli was studied by using laser scanning confocal microscopy (LSCM). RESULTS: The largest decline (p < 0.05) of hemoglobin levels was detected in animals, infected with E. coli strains with a high levels of antiHbA and HA (58.3 ± 0.6 g/l and 69.7 ± 1.1 g/l). Using LSCM, microogranisms with a high levels of antiHbA were established to penetrate erythrocytes more frequently (70 ± 3.4%), than with a low (5.5 ± 1.7%). CONCLUSION: The largest frequency of bacteria detection in erythrocytes and the highest decline of blood hemoglobin levels were noted during infection of animals with E. coli strains with high anti-hemoglobin activity.

[IMMUNE REGULATORY PROPERTIES OF BIFIDOBACTERIA METABOLITES DURING EUBIOSIS AND DYSBIOSIS OF THE HUMAN COLON].

AIM: Evaluate immune regulatory properties of bifidobacteria metabolites during eubiosis and dysbiosis of the human colon. MATERIALS AND METHODS: Anti-cytokine activity of metabolites of bifidobacteria clinical strains and their ability to influence the production of pro- and anti-inflammatory cytokines (IL-10) by peripheral blood mononuclear cells of healthy humans was studied, taking into account microecological state of the human intestine. Determination of final concentration of cytokines in experimental and control samples was carried out by EIA. RESULTS: Sensitive parameters, that are suitable for evaluation of stability of human intestine microsymbiocenosis, were detected. The level of microbial seeding, concentration of TNF-α and anti-lysozyme activity turned out to be informative for bifidobacteria in eubiosis conditions. The ability of bifidoflora metabolites to influence the production of pro-inflammatory cytokines (INF-γ, TNF-α, IL-8) by human mononuclears was a significant parameter during formation of 1 - 3 degree dysbiosis. CONCLUSION: The maintenance of physiological state of intestine homeostasis is determined by immune regulatory properties of bifidobacteria metabolites, that is realized via their interaction with both cytokines (anti-cytokine activity) and production of cytokines by host immune cells (peripheral blood mononuclears).

[AEROMONAS BACTERIA ISOLATED FROM BITHYNIIDAE MOLLUSKS AND THEIR HABITATS: SPECIES COMPOSITION AND BIOLOGICAL PROPERTIES. COMMUNICATION 1].

The purpose of this investigation was to study the species composition and biological properties of Aeromonas bacteria isolated from Bithyniidae mollusks and their habitat (a water reservoir). The Bithyniidae mollusks and water from their habitat were the material to be studied. A total of 176 Aeromonas strains were isolated from the mollusks and water. A. veronii, A. hydrophila, and A. ichthiosmia were most common in the mollusks and A. veronii and A. ichthiosmia were in the water. All the strains isolated had hemolytic activity and no lysozyme or plasma coagulase activity. The magnitude of lecithinase and antilysozymic activities and biofilm formation of the Aeromonas bacteria varied with the isolation source of their strains.

[THE STRUCTURE AND SOME BIOLOGICAL PROPERTIES OF GRAM-NEGATIVE BACTERIA CONSTITUTING THE MICROSYMBIOCENOSIS OF PROSOBRANCHIA MOLLUSKS (BITHYNIIDAE). COMMUNICATION 2].

The goal of this investigation was to study the structure and biological properties (antilysozymic, activity and biofilm formation) of gram-negative bacteria isolated from Bithyniidae mollusks and their habitat (water reservoir waters and soil). A total of 160 gram-negative bacterial strains isolated from the mollusks of the Bithyniidae family and their habitat were the material to be, studied. Psedomonas, Comamonas, and Acinetobacter held the lead in the structure of microbiocenosis of Bithyniidae mollusks, the first intermediate host of Opisthorchis filineus, while Acinetobacter did in the habitat. The antilysozymic activity of the water strains was shown to be an order of magnitude higher than that of the strains isolated from the mollusks.

[Protein profile strain specificity of Bifidobacterium genus members].

AIM: Analysis of differences in protein spectra of various bifidobacteria strains of intestine microsymbiocenosis using identification results from MALDI-TOF mass-spectrometer. MATERIALS AND METHODS: Results of mass-spectrometry ("Bruker Daltonics", Germany) for 57 intestine isolates' of Bifidobacterium spp. are provided. 500,laser impulses were used for obtaining every mass-spectrum; parameters of mass-spectrometer were optimized for the 1000-18000 m/z (mass to charge) range. RESULTS: Comparative analysis of mass-spectrometry biomarkers for Bifidobacterium genus members has detected variations in the quantity of peaks (4 to 56) among both various species and within bifidobacteria species, that reflects uniqueness of the protein profile of separate strains. Along with biomarkers, specific for most cultures, significant differences of the examined peaks were detected; including among microorganisms, that belong to the same species. As such, for B. bifidum species strains--only in 67 ± 7.5% of cultures the presence of common peaks in'the 9282-9901 m/z was detected, whereas protein spectra in other ranges differed by both quantity and molecular mass. CONCLUSION: Differences in protein profile of Bifidobacterium genus microorganisms reflect uniqueness of protein spectra (proteome) of every separate strain; determining their functional activity, features of interaction, with associative microsymbionts and host organism in human associative symbiosis.

[THE ROLE OF BIFIDOBACTERIA IN THE FORMATION OF HUMAN IMMUNE HOMEOSTASIS].

In the review the materials on the formation of intestinal immune homeostasis through involvement of bifidobacteria which are the key species of microbiota of human colon biotype are presented. Key function of dominant microorganisms, bifidoflora in particular, in intestinal biotype of a host is carried out by means of maintenance of self microorganisms and pronounced antagonism concerning non-self. Realization of this principle in intermicrobial relations allowed to develop algorithm of microbial self-non-self discrimination in microsymbiocenosis on the basis of detected opposite phenomenon (enhancement/suppression) of the main physiological functions of microsymbionts survival (reproduction and adaptation) in dominant-associant pair. Primary discrimination of foreign,material by bifidobacteria is the initial stage of the following "signaling" in the regulation of host immune homeostasis. Further stages of regulation occur by activation of dendritic cells by bifidobacteria with the sequential influence on differentiation of Th0 towards regulatory lymphocytes. The formation of Treg and regulation of immune homeostasis are carried out by bifidobacteria: due to direct activation of dendritic cells (ligand-receptor interactions) and maintenance of optimal cytokine balance.

[BIOLOGICAL PROPERTIES OF BACTERIA OF THE FAMILY ENTEROBACTERIACEAE AS COMPONENTS OF MICROSYMBIOCENOSIS OF THE FIRST INTERMEDIATE HOSTS OF O.FELINEUS].

The objective of the investigation was to study the biological properties (antilysozyme activity (ALA), biofilm formation (BFF), and virulence factors) of different Enterobacteriaceae species isolated from Bithyniidae mollusks and their habitats. A total of 117 strains isolated from Bithyniidae mollusks of the genera Codiella and Bithynia and those from their habitats were the material to be studied. Thus, comparison of the mean values of ALA in Enterobacteriaceae species suggests that the strains isolated from the mollusks and their aqueous habitat did not virtually differ in this indicator. Also, there were no statistically significant differences in the detection rate of the Enterobacteriaceae strains having a pronounced antilysozyme activity and in that of mollusks circulating in the aqueous habitat when compared with the strains isolated from the mollusks. Comparison of BFF in the aqueous bacterial strains and mollusk microbiota representatives revealed the highest values in the former; just lower value was noted in the latter. Soil Enterobacteriaceae isolates had very low BFF values.

[Application of multiplex-PCR for bifidobacteria and propionibacteria genus identification].

AIM: Creation of a PCR test-system for determination of Actinobacteria class bacteria belonging to 2 genera that are the most widely represented among obligate anaerobic microbiota of human intestine: Bifidobacterium and Propionibacterium. MATERIALS AND METHODS: 8 strains of Bifidobacterium spp. and 6 strains of Propionibacterium genus were identified by morphologic, cultural and biochemical properties. Isolation of matrix DNA of the strains for PCR was carried out by "DNA-Express" kit (SPF "Lytech", Russia). Primers for determination of genus membership for obligate anaerobes were developed based on variability of 16S RNA gene by using "Lasergene 7.1" ("DNASTAR, Inc.", USA) program. PCR screening of the isolated DNA was carried out based on "Syntol" LLC primers and reagents. Amplicon detection was carried out by agarose gel electrophoresis. RESULTS: Multiplexing of 2 different primer pairs in a single probe at.68 degrees C annealing temperature for 30 cycles showed the presence of non-specific amplicons that form in samples with bifidobacteria DNA-matrix. The increase of annealing temperature to 70 degrees C and reduction of the number of PCR cycles to 25 resulted in the exclusion of formation of non-specific amplicons. Because the annealing temperature reached the level of values optimal for Taq-polymerase, a 2-phase PCR algorithm could be implemented. This solution allowed reducing the overall time of reaction to 45 minutes. Further increase of annealing temperature to 72 degrees C and reduction of elongation phase up to 15 seconds at 30 PCR cycles did not result in a visible reduction of reaction effectiveness: CONCLUSION: A rapid system for identification of Bifidobacterium and Pronionibacterium genera using a system of 2-phase multiple PCR was developed. The system is part of a screening system for identification of major genera and species of cultured obligate anaerobic bacteria isolated from human intestine biotopes.

[The role of pro- and antioxidants of microorganisms in regulation of symbiosis homeostasis mechanisms (on the model of human vaginal biotope)].

AIM: Study the production of bacterial pro- and antioxidants in vaginal biotope and analysis of their role in regulation of symbiosis homeostasis mechanisms. MATERIALS AND METHODS: Hydrogen peroxide, catalase inhibitors and antioxidant production in bacteria isolated from 63 women with vaginal eubiosis and 53--with dysbiosis were studied. Production of pro- and antioxidants was regulated by lactate, volatile fatty acids, polyamines and Lactobacillus plantarum and Corynebacterium minutissimum polysaccharides, metabolite bactericidity of peroxide producing lactobacilli was enhanced by addition of iron (II) ions. RESULT: A high level of pro- and antioxidant production was noted for eubiosis state, and their ratio was close to 1, for biotopes with dysbiosis a multiple predominance of microbial antioxidant levels over pro-oxidants was characteristic. Peroxide producing symbionts are an important component of system of generation of hydroxyl radicals that are highly effective wide specter disinfectants. CONCLUSION: Maintenance of balance of pro- and antioxidant production by symbionts determined vaginal biotope symbiosis homeostasis. The detected high biocidic activity of hydroxyl radicals that are formed from hydrogen peroxide of normoflora through the creation of optimal conditions for their generation by selection of the respective concentrations of iron (II) ions and H2O2 opens perspective of development of novel disinfection methods.

[Comparative characteristics of HLA system gene distribution in patients with lung tuberculosis of the Russian population of Chelyabinsk region].

AIM: Study of distribution of genes and HLA system haplotypes A, B, DRB1, DQA1, DQB1 in healthy individuals and patients with lung tuberculosis, members of the Russian population of Chelyabinsk region for isolation of risk markers for the development of various forms of tuberculosis. MATERIALS AND METHODS: The study group consisted of 86 patients with lung tuberculosis of the Tuberculosis Dispensary No. 3 of Chelyabinsk of Russian nationality. 239 healthy donors of Chelyabinsk Hemotransfusion Station of Russian nationality composed the comparison group. HLA-typing was carried out by multi-primer polymerase chain reaction--PCR SSP, HLA II genotyping--by DNA technology (Russia) kits, HLA class I--by methods described in the article by Downing J.M.G. et al. (2004). Result detection was carried out by electrophoresis. RESULTS: In lung tuberculosis patients high frequency of detection of HLA haplotype DRB1*16-DQA1*01:02-DQB1*05:02/4 was established. In patients with fibrous-cavernous form B*08 and DRB1*03 gene frequency of detection increased and DRB1*07 and DQA1*02:01 genes did not occur. During focal form high frequency of HLA B*15 and HLA DRB1*15 alleles was determined compared with infiltrative form. HLA A*01-B*08-DRB1*03-DQA1*05:01-DQB1*02:01 haplotype only occurred ingroups of patients with more severe forms of tuberculosis. CONCLUSION: Markers of sensitivity to clinical phenotypes of tuberculosis were isolated.

[Periplasmic lysozime inhibitior PliC and its role in antilysozime activity of enterobacteria].

Two families of specific inhibitors of type C lysozyme (Ivy and PliC) secreted from the periplasmic space are known in enterobacteria. Microbial capacity for distant lysozyme inactivation (antilysozyme activity) is most pronounced in the strains and species carrying homologues of the pliCgene. The pliC homologue localized in a -200-kbp megaplasmid of Klebsiella pneumoniae was shown to differ significantly in the amino acid composition of the coded polypeptide. Similar to the Salmonella enterica pliC homologue, it possesses a detachable signal part and contains identical functionally critical amino acids of the active center of the inhibitor. Antilysozyme activity of the pliC-positive K. pneumoniae strains was observed at the level corresponding to the highest values found inpliC-positive S. enterica. High level of the antilysozyme activity in K. pneumoniae strains containing the plasmid pliC homologue was found in all studied strains, unlike S. enterica strains carrying the known chromosomal pliC homologue.