[The Drosophila CG9890 Protein is Involved in the Regulation of Ecdysone-Dependent Transcription].

Previously we showed that the CG9890 protein, which has zinc finger domains, interacts with ENY2-containing complexes and is localized mainly on the promoters of active genes. The CG9890 protein is involved in the regulation of the expression of some of the genes on the promoters of which it is located, and among these genes there are genes for the ecdysone cascade. In this work, the role of the CG9890 protein in the regulation of ecdysone-dependent inducible transcription was studied. For this, 12 ecdysone-dependent genes on the promoters of which the CG9890 protein is localized were identified. Their activation was studied after the addition of 20-hydroxyecdysone to cells, both in normal conditions and after RNA interference of CG9890. The expression of ecdysone-dependent genes is significantly increased in response to the treatment of cells with ecdysone, in contrast to the control genes. Moreover, in the cell line after RNA interference CG9890, the transcription of 8 out of 12 genes was significantly higher than in the control line. Thus, the CG9890 protein is involved in the regulation of transcription of ecdysone-dependent genes, and, in most cases, acts as a repressor.

Pseudomonas aeruginosa efflux pump superfamily (review of literature).

The significant increase in the number of antibiotic-resistant microorganisms observed in recent years is a public health problem worldwide. One of the molecular mechanisms for the formation of antimicrobial resistance in bacteria is the presence of efflux pumps. The review presents an analysis of experimental studies related to the study of efflux pumps in clinical strains of Pseudomonas aeruginosa, one of the representatives of hospital pathogens of the ESKAPE group. This review is intended for specialists developing new types of drugs against antibiotic-resistant strains, as well as researchers studying the mechanisms of bacterial resistance to antibiotics, heavy metals, biocides and other antimicrobial factors.

The sensitivity of planktonic cultures and biofilms of gram-negative bacteria to commercial disinfectant and antiseptic preparations.

The in vitro antibacterial activity of 11 commercial disinfectant preparations and 8 antiseptics against 10 strains of the bacteria Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloaceae and Providencia stuartii obtained from international collections and isolated from neuroresuscitation patients in Moscow in 2018 was studied. The sensitivity of planktonic cultures to the preparations was determined by the method of serial dilutions in broth and the spot method on solid nutrient media, the sensitivity of biofilms by the applicator method. A general pattern was revealed: the level of sensitivity to tested disinfectants in clinical strains was lower than in reference strains. It was found that the disinfectants «Mikrobak-Forte¼, «SAT-22¼, «Neobak-Oksi¼ at the concentrations recommended by the manufacturers were effective against bacteria of all test strains, both in the plankton state and in the form of biofilms. On the contrary, the disinfectant preparations «Biodez-Optima¼, «Biodez-Extra DVU¼, «Novodez-Aktiv¼, «Triosept-Oksi¼, «Tristel Fusion for Surfaces¼, «Effect-Forte Plus¼, «Lactic-Oxy¼ did not have sufficient effectiveness in the concentrations recommended by the manufacturers, therefore it is proposed to use these drugs in higher concentrations. It was found that the disinfectant «Biodez-Extra DVU¼ is able to inhibit the growth of biofilms of bacteria of the species K. pneumoniae. The ability to suppress the growth of bacterial biofilms of K. pneumoniae, A. baumannii, P. aeruginosa was revealed for the «Triestel Fusion for surfaces disinfectant¼. The bacteria of all used test strains in the planktonic state were sensitive to all tested antiseptic preparations. However, the biofilms of the clinical strains of P. aeruginosa and P. stuartii. possessed resistance to the antiseptics «Octenidol¼, «Octenisept¼, «Miramistin¼, «Hexoral¼. Our studies indicate the need for sensitivity analysis of antibacterial drugs in representatives of hospital pathogens, including the modeling of bacterial biofilms, which is a very relevant and important scientific direction, necessary to improve the control of nosocomial infections in the Russian Federation.

A study of antibiotic and disinfectant susceptibility of Elizabethkingia meningoseptica.

For the local health service, Elizabethkingia meningoseptica remains a relatively new and little-known pathogen, whereas in many countries of Europe, Asia and other continents it is considered as a potential causative agent of nosocomial infections, especially in premature infants and immunocompromised patients. An analysis of the literature data, as well as our results indicate that E. meningoseptica should be considered as a potential pathogen, which is characterized by a unique profile of susceptibility to antimicrobial agents (AMP) and disinfectants. This article presents the results of a study of susceptibility to AMP and disinfectants of three isolates of E. meningoseptica, isolated during an investigation of an outbreak in one of the perinatal centers of the Russian Federation, where three cases of sepsis with a fatal outcome in premature infants caused by co-infection with Acinetobacter baumannii and E. meningoseptica were recorded between January and February 2016.

Next-Generation Antibiotics, Bacteriophage Endolysins, and Nanomaterials for Combating Pathogens.

This review presents various strategies to fight causative agents of infectious diseases. Species-specific programmable RNA-containing antibiotics open up new possibilities for creating next-generation of personalized drugs based on microbiome editing and can serve as a new tool for selective elimination of pathogenic bacterial species while keeping intact the rest of microbiota. Another promising approach in combating bacterial infections is genome editing using the CRISPR-Cas systems. Expanding knowledge on the molecular mechanisms of innate immunity has been actively used for developing new antimicrobials. However, obvious risks of using antibiotic adjuvants aimed at activation of the host immune system include development of the autoimmune response with subsequent organ damage. To avoid these risks, it is essential to elucidate action mechanisms of the specific ligands and signal molecules used as components of the hybrid antibiotics. Bacteriophage endolysins are also considered as effective antimicrobials against antibiotic-resistant bacteria, metabolically inactive persisters, and microbial biofilms. Despite significant advances in the design of implants with antibacterial properties, the problem of postoperative infections still remains. Different nanomodifications of the implant surface have been designed to reduce bacterial contamination. Here, we review bactericidal, fungicidal, and immunomodulating properties of compounds used for the implant surface nanomodifications, such as silver, boron nitride nanomaterials, nanofibers, and nanogalvanic materials.

[Phenotypic and molecular genetic properties of Escherichia coli clinical strains isolated from patients with urological diseases].

OBJECTIVE: Microbiological and molecular genetic characterization resistance profiles of Escherichia coli strains isolated in a pilot single-center clinical study from patients of the urological department in Yaroslavl in 2016-2017. MATERIALS AND METHODS: Clinical strains of E. coli (n=18) were isolated from the urine of women aged 23-84 years. The mobility of bacteria, colicinogenicity, and sensitivity to lactobacilli antagonism, biofilm formation, and susceptibility to antimicrobials were evaluated. The antibiotic resistance genes were identified. RESULTS: The E. coli strains had a wide heterogeneity in mobility, colicinogenicity, and biofilm formation. They were sensitive to Lactobacillus acidophilus antagonism, as well as to nitrofurantoin, meropenem, fosfomycin and the main functional classes of disinfectants and antiseptics, but are resistant to beta-lactams, fluoroquinolones and aminoglycosides. The mcr-1 gene providing resistance to colistin was identified in two strains. CONCLUSIONS: Analysis of genetic antibiotic resistance determinants revealed the genetic diversity of clinical E. coli strains. The obtained data on the strain sensitivity to antibacterials and disinfectants can be used by clinicians in choosing the optimal antibiotic therapy and treatment of abiotic surfaces in urological departments.

[Antimicrobial activity of dioxidine and a dioxidin-containing preparation «Nosolin-Ultra, nasal drops¼.]

The study is devoted to the study of the antimicrobial activity of the antioxidant dioxidin and the complex dioxin-containing preparation Nosolin-ultra, nasal drops against planktonic and biofilm cultures of pathogens of ENT infections, the dynamics of the formation of microbial resistance to dioxidine. 11 reference strains and 9 clinical strains of microorganisms were used in the study: Streptococcus spp., Staphylococcus spp., Micrococcus luteus, Haemophilus influenzae, Acinetobacter pittii, Klebsiella pneumoniae, Moraxella catarrhalis, Pseudomonas aeruginosa. The antimicrobial activity of preparations against planktonic cultures was determined by serial dilution in broth and spot method on solid nutrient media, against biofilms by the applicator method. The dynamics of dioxidine resistance formation was studied by passaging cultures in a liquid nutrient medium with increasing concentrations of antiseptic. Based on the study, it was found that Dioxidin showed antimicrobial activity against plankton cells of all strains (MBC=0.08-5 mg/ml), except S. pyogenes SN345 (MBC>5 mg/ml), inhibited the growth of formed biofilms (MBC=0.08-2.5 mg/ml) of all strains except S. pyogenes SN345 (MBC>5 mg/ml). The drug «Nosolin-ultra, nasal drops¼ was highly active against plankton cells (MBC=0.04-0.63 mg/ml) and biofilms (MBC=0.02-0.31 mg/ml) of gram-negative bacteria, except A. pittii (MBC>2.5 mg/ml), less active against plankton cells (MBC=1.25-2.5 mg/ml) and biofilms (MBC=0.02-0.31 mg/ml) of gram-positive bacteria and C. albicans. One strain (S. aureus) formed a variant resistant to dioxidine at a concentration of 20 mg/ml, which exceeded the concentration of dioxidine in the complex preparation; other strains (P. aeruginosa, K. pneumoniae, C. albicans) did not form such variants. The data obtained indicate that the drug «Nosolin-ultra, nasal drops¼ can be effectively used against most pathogens of ENT infections. It is worth noting that with prolonged use of the drug for some types of ENT pathogens in the future, a slight decrease in effectiveness may be noted.

Drosophila Zinc Finger Protein CG9890 Is Colocalized with Chromatin Modifying and Remodeling Complexes on Gene Promoters and Involved in Transcription Regulation.

In this work, we conducted a genome-wide study of the zinc finger protein CG9890 and showed that it is localized mostly on the promoters of active genes. The CG9890 binding sites are low-nucleosome-density regions and are colocalized with the chromatin modifying and remodeling complexes SAGA and dSWI/SNF, as well as with the ORC replication complex. The CG9890 protein was shown to be involved in the regulation of the expression of some genes on the promoters of which it is located, with the ecdysone cascade genes accounting for a significant percentage of these genes. Thus, the CG9890 protein is a new member of the transcriptional network which is localized on active promoters, interacts with the main transcription and replication complexes, and is involved in the regulation of both basal and inducible transcription.

[Promising races of baker's yeast for the production of food ingredients enriched with selenium and chromium].

It is known, that Saccharomycetes can accumulate mineral substances with targeted enrichment of the growth medium. However, the influence of the genetic affiliation of the culture and the technological factors of yeast strains, the composition of growth media on the efficiency of essential trace elements incorporation into the biomass and on the change of theirs intracellular components content have hardly been investigated. In this regard, the aims of this work was to select promising races of yeast Saccharomyces cerevisiae, develop a biotechnological method for obtaining food ingredients enriched with selenium and chromium on their basis, and study their trace element composition. Material and methods. Industrial strains of baker's yeast (Saccharomyces cerevisiae) were used: RCAM 01137, Y-3439 and Y-581. Yeast were grown on malt wort (pH 4.6) with a dry matter content of 12% with the addition of mineral salts in stationary conditions at a temperature of 30 °C for 18 h, after which the yeast biomass was separated by centrifugation. A method for enriching yeast with trace elements has been selected, which consists in the process of culturing cells on malt growth media containing chromium chloride or selenium dioxide in various concentrations. The total protein content was determined by the Kjeldahl method, polysaccharides and ergosterol - by spectrofluorometric method, selenium - by fluorimetric method. The content of trace elements in yeast biomass enriched with chromium was studied by mass spectrometric method with inductively coupled plasma. Results. It was shown that the highest specific growth rate was demonstrated by the yeast strains RCAM 01137 and Y-3439, and the highest level of maltase activity was in the Y-581 strain. It was found that the amount of biomass after cultivation of the yeast S. cerevisiae RCAM 01137 and Y-3439 was 6.00 и 5.42 g/100 cm3, respectively. It was noted, that the yeast S. cerevisiae Y-581 had capability of high synthesis of ergosterol (1.08±0.04%), the level of which was 2 fold higher than other strains. S. cerevisiae RCAM 01137 yeast showed the greatest ability to selenium enrichment, its content in biomass increased 137 fold and amounted to 2740 µg% when cultivated on a medium containing 800 µg/dm3. S. cerevisiae Y-581 yeast strain showed the highest capability to chromium sorption. The chromium concentration in its biomass was 8340 µg% in case of cultivating on a medium containing 750 µg/dm3. The usage of about 2.7 g of selenium enriched yeast biomass, or 1.0 g chromium enriched one, satisfies the daily requirement for these trace elements. Conclusion. Cultivation of S. cerevisiae cells on growth media containing trace elements makes it possible to obtain yeast biomass samples that can be used to obtain food ingredients for creating food products that contribute to the maintaining human health and improve the quality and duration of life.

[Trials of the domestically produced nutrient medium «Agar Muller-Hinton II - Obolensk¼.]

The results of the comparative tests of the «Agar Muller-Hinton II - Obolensk¼ nutrient medium developed in SRCAMB, Obolensk, and the control nutrient medium imported «Mueller Hinton II Agar¼ are presented in the study. The susceptibility of bacterial clinical strains to antimicrobial agents (AMP) was determined by the disc diffusion method and the method of gradient diffusion (E-test). The carbapenemase activity of the strains carrying the carbapenemase genes was determined by CIM-test. Total 173 characterized bacterial strains of species Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Serratia marcescens, Enterobacter aerogenes, Escherichia coli; Photorhabdus spp., Staphylococcus aureus, Enterococcus spp. were used in the study, including producers of OXA- and NDM-types carbapenemases for gram negative bacteria. A high degree of coincidence of the results obtained on both nutrient media was shown. The consistency index of the strain sensitivity categories to AMPs (S, I, and R) was 98.2% for the disc diffusion method, and 94.4-100% - for E-test and CIM-test methods. Thus, within the framework of the Import Substitution Program, the domestic nutrient medium «MHA II-Obolensk¼ has been successfully developed. The nutrient medium meets the requirements of GOST R ISO 20776-2-2010 «Clinical laboratory testing and in vitro diagnostic test systems - Susceptibility testing of infectious agents and evaluation of performance of antimicrobial susceptibility test devices¼.

[The study of patterns of development of resistance of Staphylococcus aureus to triclosan].

The article presents the results of studying molecular genetic mechanisms of development of resistance to antiseptic Triclosan in strain Staphylococcus aureus АТСС25923. The modifcations of strain S. aureus АТСС25923 (Tr1, Tr2, Tr1С и Tr2С) are obtained resistant to 64 mg/l of Triclosan and stably preserving the given characteristic under cultivation in absence of selective pressure. The strain S. aureus Tr1was characterized by slightly delayed growth and the strain S. aureus Tr2 was characterized by growth velocity comparable with initial strain. In the Triclosan-resistant strains a mutation C284T in gene fabI was detected resulting in amino-acid replacement A95V in enzyme enoyl-acyl protein reductase FabI, triclosan target. Besides, in these strains a stably inheriting mutation was detected in genes associated with transport of substances in cell: hypothetical transport protein HlyC/CorC family transporter, protein-transporter of ions of Na+, K+, Li+ and alkali of Na+/H+ antiporter subunit F, membrane hypothetical protein and ATP-binding protein. It is demonstrated that resistance to triclosan in staphylococci is associated with acquirement of point mutations in genes of enoyl-acyl protein reductase and also in other genes related to transport of substances in bacterial cell.

Zinc Finger Protein CG9890 - New Component of ENY2-Containing Complexes of Drosophila.

In previous studies, we showed that the insulator protein Su(Hw) containing zinc finger domains interacts with the ENY2 protein and recruits the ENY2-containing complexes on Su(Hw)-dependent insulators, participating in the regulation of transcription and in the positioning of replication origins. Here, we found interaction between ENY2 and CG9890 protein, which also contains zinc finger domains. The interaction between ENY2 and CG9890 was confirmed. It was established that CG9890 protein is localized in the nucleus and interacts with the SAGA, ORC, dSWI/SNF, TFIID, and THO protein complexes.

[Biodegradation of proteins of grain raw materials for the production of new bakery products].

The effect of enzyme systems on the degree of protein destruction of grain crops to obtain new types of bakery products has been studied. Protein and amino acid composition of triticale grain crop in comparison with wheat and rye one has been studied. The high biological value of triticale proteins containing 38.75% of essential amino acids while in wheat - 34.93% has been shown. The influence of different enzyme systems (ES) with proteolytic action on the efficiency of catalytic modification of triticale proteins has been investigated. It was found that the highest activity was shown by the enzymatic system ES-1, synthesized by the mycelial fungus Aspergillus oryzae, as a result of which at a concentration of 5 u/g, the level of accumulation of amine nitrogen in triticale enzymatic hydrolysates was 125 mg%; the degree of hydrolysis of proteins was 90%. Enzyme preparations of bacterial origin, as well as alkalase and papain had a lower ability to hydrolyze triticale proteins. The fractional composition of modified proteins obtained by ES-1 showed a decrease in their molecular weight (to 35 kDa). Analysis of amino acid composition in grain enzymatic hydrolysates showed that as a result of exposure to FS-1, about 50% of the total number of amino acids passed into the free state, of which 38.8 to 43.6% were essential amino acids. The recipes of breads, containing composition of wheat flour and fermentolizates of the whole-grain triticale flour in the ratio 1:1 have been tested. The amino acid composition of the bread showed that the test samples contained 6.2 fold more free amino acids than the control. The use of fermented triticale in the recipes of bread allowed to increase the content of essential amino acids such as methionine, valine, isoleucine, leucine, phenylalanine, threonine, tryptophan and lysine in 2.0-5.0 times. It was shown that the developed technology allowed baking bread containing peptides with reduced molecular weight and free amino acids, which by its organoleptic and physic-chemical parameters corresponded to classic bakery products.

[The characteristic of diarrheagenic Escherichia separated from children aged under 5 years old in Yaroslavl.]

The diarrheagenic bacteria coli take a significant place among agents of acute intestinal infections in children aged under 5 years. The main danger among these pathogens is represented by both enterotoxigenic E. coli causing enteritis and enterocolitis accompanied by acute dehydration diarrhea and Escherichia producing shiga-toxin being agents of hemorrhagic colitis and hemolytic uremic syndrome. The fast and proper identification of agents of these two groups of pathogens is an important task of bacteriologists to be resolved for successful treatment of patient because tactics of therapy of enterotoxigenic diarrhea and hemorrhagic colitis and hemolytic uremic syndrome significantly differ. The high capacity of Escherichia coli to form populations resistant to anti-microbial medications, including pan-resistant ones, also is a serious problem for science and public health. The object of study was a collection of isolates of E. coli (n = 112), separated from 112 children aged under 5 years with clinical manifestations of acute intestinal infection, food toxic infection hemocolitis and diarrhea of obscure etiology in Yaroslavl in 2015-2017. Initially, the strains of E. coli were tested using diagnostic agglutinating coli-serums and then using reagents' kit «AmpliSens®Escherichiosis-FL¼ for detection and differentiation DNAof diarrheagenic bacteria coli and also with specific oligonucleotide primers to genes of virulence and O-serum group belonging. The obtained data permitted to determine belonging of analyzed strains of E. coli to four sub-groups: ЕНЕС (n = 9), EPEC (n = 17), ETEC (n = 1) и EAgEС (n = 1). All of them were agents of genes of pathogenicity specific for every pathogroup. The most numerous group EPEC was represented by strains of five serogroups with dominating among them serogroup O26 (9 strains). Therefore, studying collection of strains of diarrheagenic Escherichia isolated during 2015-1017 in Yaroslavl from children aged under 5 years with acute intestinal infections permitted to demonstrate efficiency of application of molecular genetic methods of analysis for characterizing E. coli i.e. establishment their serogroups, detection of genes of virulence and attributing to pathogroups.

[Molecular-genetic characterization of shiga-toxin producing Escherichia coli isolated during a food-borne outbreak in St. Petersburg in 2013].

UNLABELLED: Shiga toxin-producing Escherichia coli (STEC) food-borne infections are reported worldwide and represent a serious problem for public healthcare. In the Russian Federation there is little information on epidemiology and etiology of STEC-infections as well as on molecular-genetic peculiarities of STEC pathogens. OBJECTIVE: Our aim was to describe a food-borne outbreak as hemorrhagic colitis (HC) along with hemolytic uremic syndrome (HUS), enterocolitis, and acute gastroenteritis in children in St. Petersburg in 2013. METHODS: Epidemiological, microbiological, molecular-genetic and bioinformatic methods were applied. RESULTS: Objects to study were clinical specimens, milk and food samples, as well as STEC strains isolated during the outbreak. The outbreak of food-borne infection was found to be caused by STEC-contaminated raw milk as confirmed by epidemiological analysis, detection of STEC DNA and isolation of relevant pathogens in milk and sick children fecal specimens. The whole-genome sequencing revealed two groups ofpathogens, E. coli O157:H7 and E. coli O101:H33 among collected strains. Group I strains were attributed to the previously known sequence type ST24, while group II strains belonged to the previously non-described sequence type ST145. In strain genomes of both groups there were identified nucleotide sequences of VT2-like prophage carrying stx2c gene, plasmid enterohemolysin gene, and gene of the STEC main adhesion factor intimin. Gene of intimin gamma was identified in E. coli O157:H7 strains and intimin iota 2 in E. coli O101:H33 strains. The latter previously was identified only in enteropathogenic E. coli (EPEC) strains. CONCLUSION: The additional knowledge of epidemiology and biology of STEC pathogens would assist clinicians and epidemiologists in diagnosing, treating and preventing hemorrhagic colitis.

[Mechanical corneal injury diagnosis using infrared spectroscopy].

Method for express diagnosis of mechanical corneal injury using infrared spectroscopic analysis of tear fluid is proposed. Differential diagnosis of open and closed corneal injuries in absence of clinical data is presented. Clinical material is provided by patients with open globe injuries--25 patients (25 eyes) and 25 patients (25 eyes) with closed globe injuries. 20 healthy adults (40 eyes) were included into the control group. Proposed method allows to develop treatment strategy, determine extent of surgical interventions in corneal trauma and predict the course of posttraumatic process and complications as well.

The novel CTX-M-116 ß-lactamase gene discovered in Proteus mirabilis is composed of parts of the CTX-M-22 and CTX-M-23 genes.

The novel ß-lactamase gene bla(CTX-M-116) was identified in a Proteus mirabilis nosocomial isolate recovered from the urine of a patient in Moscow in 2005. DNA sequence analysis showed bla(CTX-M-116) to be a hybrid gene consisting of 5' bla(CTX-M-23) (nucleotides 1 to 278) and 3' bla(CTX-M-22) (nucleotides 286 to 876) moieties separated by an intervening putative site of recombination (GTTAAAT). A retrospective analysis of available bla(CTX-M) genes in the GenBank database revealed 19 bla(CTX-M) genes that display the same hybrid structure.

Probiotic Activity of a Bacterial Strain Isolated from Ancient Permafrost Against Salmonella Infection in Mice.

Bacillus cereus strain F, collected from relict permafrost located in Siberia, was analyzed for probiotic activity in the mouse Salmonella enterica model. Viable bacterial cells were found in frozen soils taken at Mammoth Mountain in Yakutia from a depth below the level of seasonal thawing. Geological data indicated the absence of a thawing within millions of years of deposited soils, which helped to ensure the ancient origin of our sample. According to DNA analysis, bacterial cells collected from the relict permafrost appeared to be B. cereus strain F. The morphology of these bacteria was analyzed using atomic force microscopy. B. cereus strain F was assessed as a nonpathogenic bacterium by evaluation of its pathogenicity. A S. enterica model is described in mice after per oral inoculation and serves as a model for the human carrier state. Using this model, probiotic activity by the bacterial strain isolated from the ancient permafrost has been shown against Salmonella infection in mice.

[Antimicrobial activity of bacteriocin S760 produced by Enterococcus faecium strain LWP760].

Antimicrobial activity of bacteriocin S760 (enterocin) produced by Enterococcusfaecium strain LWP760 was studied. Bacteriocin S760 is a cationic, hydrophobic, and heat stable peptide with the molecular weight of 5.5 kDa and pl of 9.8. Enterocin S760 is shown to inhibit in vitro the growth both of sensitive and resistant to antibacterials gramnegative and grampositive bacteria of 25 species. MICs of the bacteriocin S760 vary between 0.05-1.6 mg/l for Escherichia coli 0157:H117, Salmonella typhimurium, Salmonella enteritidis, Campylobacter jejuni, Yersinia enterocolitica, Yersinia pseudotuberculosis, Listeria monocytogenes and Clostridium perfringens, that are main food-borne pathogens, and from 0.4-1.6 mg/l for Streptococcus pyogenes, Streptococcus pneumoniae and Corynebacterium diphteriae. It is also active against antibioticresistant strains of Staphylococcus aureus, Enterobacter cloacae, Acinetobacter baumannii (with MICs of 0.05-3 mg/l), Klebsiella pneumoniae (with MICs of 6 mg/l), Pseudomonas aeruginosa (with MICs of 0.4-25 mg/1), as well against fungi belonging to species of Candida albicans, Candida krusei and Aspergillus niger (with MICs of 0.1-0.2 mg/l). Enterocin S760 is a novel antimicrobial agents useful in medicine, veterinary and food industry.

[An algorithm for identification of CTX-M-type beta-lactamase genes using restriction fragment length polymorphism analysis of PCR-product].

The algorithm of the identification of the bla(CTX-M) genes coding CTX-M-type beta-lactamases providing resistance to cephalosporins III-IV was developed. This algorithm provides identification of 49 genes of 96 genes presented in the GenBank database so far. Remaining 47 genes can be identified as consisting of small sub-groups composed of 2-6 genes with the exception of sub-group of the bla(CTX-M-14)-like genes composed of 13 genes. The identification of the bla(CTX-M) genes is based on two-step restriction fragment length polymorphism analysis of 544 bp PCR-product (PCR-RFLP). In the first step, determination of subtype (cluster) of the bla(CTX-M) gene occurred using the restriction nuclease Alu I: cluster 1, -2, -8, -9 or -25. Moreover, four genes can be identified just at this step: bla(CTX-M)-59, (cluster 2); bla(CTX-M-63) (cluster 8), bla(CTX-M-45) (cluster 9), and bla(CTX-M-78) (hybrid gene between cluster 2 and cluster 25). At the second step gene identification goes on inside of each cluster separately using a set of 26 restriction nucleases. As a result of the PCR-RFLP-analysis, 23 bla(CTX-M) genes can be identified at the cluster 1, 11 genes--at the cluster 2, 4 genes--at the cluster 8, 9 genes--at the cluster 9, 1 gene--at the cluster 25, and 2 hybrid genes: bla(CTX-M-78) (between clusters 2 and 25), and bla(CTX-M-64) (between clusters 1 and 9). The described algorithm was used for identification of the blac(CTX-M) genes (n = 585) detected in Enterobacteriaceae nosocomial isolates (n = 877), collected from Russial hospitals in 2003-2007. It was shown that major genes belonged to cluster 1 (n = 543), namely--bla(CTX-M-15) gene (n = 515), bla(CTX-M-3) (n = 25), bla(CTX-M-22) (n = 1), bla(CTX-M-23) (n = 1), and bla(CTM-34) (n = 1). Moreover, the genes atributed to cluster 2 were identified: bla(CTX-M-2) (n = 1), and bla(CTX-M-5) (n = 4); and genes belonged to cluster 9: bla(CTX-M-9) (n = 2), and bla(CTX-M-14) (n = 35).