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Results from research on isolation, identification, and study of biological properties of L. monocytogenes clinical isolates and Listeria spp test strains are presented. Peculiarities of modern research methods for indicating and identifying pathogenic listeria to improve the quality of laboratory studies of clinical material are studied. The culture method provides reliable results of microbiological analyses upon detecting Listeria spp. The presented list and algorithm of the laboratory diagnostic methods can be used as a basis for elaborating regulatory documents for carrying out microbiological research on any biological material for the presence of bacteria of the genus Listeria spp. and L. monocytogenes species in it.

The purpose of the work is to evaluate the cultural and morphological properties of colonies of clinically significant corynebacteria on culture mediums for the isolation of corynebacteria. The study used 9 culture mediums for the isolation of corynebacteria: a culture medium for the isolation of corynebacteria (Corynebacagar); Tellurite-containing blood agars on base - Culture medium № 1 GRM, Culture agar for the cultivation of microorganisms (GRM agar), Culture medium for determining the sensitivity of microorganisms to antibacterial preparations - AGV, culture agar for the cultivation of dry microorganisms (SPA), Clauberg medium II, Hoyle Medium agar (Oxoid), Blood agar base (Conda), Columbia Agar Base (Conda). The work used 7 test strains of microorganisms from the State collections of pathogenic microorganisms - C. diphtheriae biovars gravis, mitis, intermedius, belfanti and subspecies lausannense, C. ulcerans and C.pseudotuberculosis. Studies were carried out in accordance with MUK 4.2.3065-13 «Laboratory diagnosis of diphtheria infection». We describe culture-morphological properties of strains on all tested culture mediums the isolation of corynebacteria after 24 and 48 hours of incubation. Analysis of the results on the growth properties of culture mediums showed that all culture mediums had high sensitivity - from dilution 10-7 for all test strains. Colonies of corynebacteria were visually detected on culture mediums after 19-20 hours of cultivation. When cultivating a suspension of corynebacteria from breeding 10-6 on culture mediums, the number of colonies ranged from 95±5 to 120±10. Conclusion. All culture mediums had differential diagnostic properties that ensure the growth of corynebacteria after the day of incubation.

The aim of the study is to assess the effectiveness of quality control of transport environments in accordance with the requirements of domestic and international standards using aerobic and optional anaerobic microorganisms. The results of a comparative assessment of the survival of 10 strains of aerobic and optional anaerobic microorganisms after storage in the semi-liquid transport environment of Ames for 24 and 48 hours at temperatures (4-8)0 C and (20-25)0 C in accordance with the requirements of domestic and international standards are presented. The methodology described in ICC 4.2.2316 causes a number of technical difficulties leading to non-reproducible results. The survival rate of microorganisms in semi-liquid transport environments under ISO 11133-2016 is of high quality. The quantitative assessment is based on two Swab Elution and Roll Plate methods recommended by the CLSI M40-A2 standard.

A comparative analysis of the quality of the developed nutrient media, Baird-Parker dry agar base and Vogel-Johnson dry agar Base and foreign analogues, was done based on results of clinical trials. The tested media were qualified by the main biological parameters, such as sensitivity, growth rate, and differentiating and inhibiting properties. The evaluation of statistical reliability of the results of trials of clinical samples was evaluated taking into account the number of parallel studies and the number of matches of the results of studies conducted by different performers. 116 clinical samples of received by a laboratory of the testing laboratory center for research from hospital no.164 over the period of clinical trials were analyzed. 46 cultures of potential pathogens were isolated when culturing on test and control media: S. aureus -35; S. epidermidis-6; S. saprophyticus - 5. Lecithinase activity on the medium “Baird-Parker dry agar Base” and mannitol fermentation on the medium “Vogel-Johnson dry agar Base” in the preliminary phenotypic test allow the isolation and differentiation of clinical isolates of S. aureus from S. epidermidis, and S. saprophyticus.

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.

The possibility of using the nutrient media complex produced by SCRAMB for the isolation, primary identification and counting of viable lactic acid bacteria and bifidobacteria in the fermented milk products was studied. Key words: Lactic acid bacteria, Lactobacillus, Streptococcus thermophilus, Lactococcus, Bifidobacterium, MRS agar, М 17 agar, OBB medium, Blikfeldt's medium

Clinical strains of Staphylococcus aureus were tested for hemolytic activity on blood agar, in the PCR test and by analyzing the gene alleles of hemolytic toxins. The study analyzed the information content of the phenotypic determination of hemolytic activity to assess the pathogenic properties of S. aureus isolates.

The results of comparative experimental studies of identification of nontoxigenic C. diphtheriae strain by three different commercial laboratories are presented. A typical nontoxigenic strain of C. diphtheriae biovar mitis was used. For the studies, three lines of ten-fold dilutions of bacterial culture were prepared, followed by control planting on the medium and counting CFU/ml. In the experiment, tampons were pooled with a 24-hour bacterial culture of a nontoxigenic C. diphtheriae strain. Tampons were provided from three different laboratories - ∑-Transwab® with Ames liquid medium (from the first and second laboratories) and a viscose tampon with coal medium (from the third laboratory). After pooled, tampons were delivered to commercial laboratories. And as a result of the experiment, Corynebacterium spp. was identified in first laboratory (103 CFU/tamp), S. epidermidis (102 CFU/ml) - in second laboratory and nontoxigenic C. diphtheriae biovar gravis - in third laboratory. The study indicates that there is a need to the supervision of bacteriological investigations conducted in various laboratories. This will improve the quality of investigations on diphtheria infection and identify of diphtheria carrier, which is a reservoir of the causative agent of diphtheria, and will contribute to the maintenance of sanitary and epidemiological well-being in our country.

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.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.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.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.

The results of the comparative testing of the susceptibility of M. tuberculosis clinical strains to isoniazid, streptomycin, rifampicin and ethambutol using the TB test kit, developed in SCRAMB, (Obolensk) and the absolute concentrations method; the TB test kit and the BACTEC MGIT 960 automated system are presented in the study. A total of 629 and 220 strains, respectively, were tested. A high degree of agreement of the results was shown: 89.1-98.6% for isoniazid, 96.2-98.0% for rifampicin, 91.5-98.2% for streptomycin and 89.1-95.9% for ethambutol. The smallest number of discrepancies in the results was obtained when comparing the TB test kit and BACTEC MGIT 960. The discrepant results analysis was performed by the proportion method, PCR sequencing, or re-testing on new lots of the TB test kit and Lowenstein-Jensen medium with anti-tuberculosis drugs, after which the sensitivity, the specificity and the efficiency of the TB test kit have exceeded 95 % for all anti-tuberculosis drugs. The turnaround time with the TB test kit (median 9.25-9.9 days, ranged from 8 to13 days) was significantly shorter than that with the absolute concentration method (median 21-23 days, ranged from 20 to 28 days) and is commensurate with the turnaround time with BACTEC MGIT 960 (average 7.2 days, ranged from 5 to 12 days). The TB test kit is easy to use, does not require expensive equipment and special staff training.

The results of the comparative tests of the «Agar Muller-Hinton II - Obolensk» nutrient medium developed in SRCAMB, Obolensk, and the control nutrient medium imported «Mueller Hinton II Agar» 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-Obolensk» 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 devices».

Salmonella infections continue to be a serious problem in modern medicine. Being intestinal infections-associated pathogens, representatives of the genus Salmonella manifest themselves as pathogenic bacteria, especially in developing nosocomial infections. Given the polymorphism of clinical symptoms of salmonellosis, laboratory studies using bacteriological and serological methods are an important link in the diagnosis. In addition, the general prevention of salmonellosis includes measures to identify bacteria carriers, to ensure control over the incidence in farm animals and birds, food safety, etc. The list of nutrient media to isolate and identify Salmonella is lengthy and steadily extending, and the choice of specific media is largely relies on the nature of the material under study as well as on the idea of the potential availability of Salmonella bacteria in it, with research, diagnosis or epidemic situation being taken into account. The SRCAMB (Rospotrebnadzor) has designed two nutrient media allowing the enrichment and isolation Salmonella from various clinical samples. These are "Nutrient Medium for Enrichment of Salmonella, Dry (Magnesium medium) and "Nutrient Agar with Brilliant Green, Phenolic Red, Lactose and Sucrose, Dry (BPLS-FMH agar)." Growth and inhibitory properties of the new culture media produced by the SRCAMB and commercial domestic and foreign counterparts have been compared by using clinical material. Domestic nutrient media such as Magnesium medium and BPLS-FMH agar were proved to correspond to their commercial analogues when being used for enrichment, isolating and counting Salmonella bacteria in clinical specimens to have bacteriological control real data.

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-FL» 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.

The cultural diagnostic of acute intestinal infections is based on application of growth medium for selective cumulation of enterobacteria. The development of composition and technology of production of national import-substituting growth medium is an important task for supporting laboratories with high quality medical products. In the state research center of applied microbiology and biotechnology are developed and registered in established procedure a dry growth medium for selective cumulation of enterobacteria (Mossel EE broth) and dry growth medium for selective isolation and counting of enterobacteria (Mossel agar). Both media are intended for selective cumulation, isolation and counting of enterobacteria of family Enterobacteriaceae in clinical material and other objects. The comparative evaluation was applied concerning growth and inhibiting characteristics of new growth media produced by the state research center of applied microbiology and biotechnology against foreign analogues using clinical material. The total correspondence of national Mossel broth and Mossel agar to foreign analogues in case of using these media with the purpose of selective cumulation, isolation and counting of enterobacteria of family Enterobacteriaceae in clinical material and obtaining objective results of bacteriolog.

The comparative tests of growth mediums for isolation and accumulation of diphtheria bacteria were implemented. The testing consisted of six series of growth medium "Corynebacagar" produced by the state research center of applied microbiology and biotechnology and three series of blood tellurite agar. The concluding results of identification of biological indicators of all series of growth nutrient mediums are presented The "Corynebacagar" is recommended for application in health care practice for primary inoculation of pathological material during implementation of cultural analysis on diphtheria.

The import substitution becomes one of the strategic tasks of national economy as a result of prolongation of economic sanctions concerning the Russian Federation of part of the USA, EU countries, Japan and number of other countries. It is not proper to be limited in import substitution only by goods because in conditions ofsanctions when access toforeign technologies is complicated Russia is needed to substitute foreign technologies by national designs in faster manner One of directions of effective import substitution is localization of production of laboratory equipment and consumables for clinical and sanitary microbiology on the territory ofthe Russian Federation and countries of Customs union. In Russia, in the field ofdiagnostic of dangerous and socially significant infections, all components for import substitution to implement gene diagnostic, immune diagnostic. bio-sensory and biochip approaches, isolation and storage of live microbial cultures, implementation of high-tech methods of diagnostic are available. At the same time, national diagnostic instrument-making industry for microbiology is factually absent. The few devices of national production more than on 50% consist of import components. The microbiological laboratories are to be equipped only with import devices of open type for applying national components. The most perspective national designs to be implemented are multiplex polimerase chain reaction test-systems and biochips on the basis of national plotters and readers. The modern development of diagnostic equipment and diagnostic instruments requires supplement of national collections of bacterial and viral pathogens and working-through of organizational schemes of supplying collections with strains. The presented data concerning justification of nomenclature of laboratory equipment and consumables permits to satisfy in fill scope the needs of clinical and sanitary microbiology in devices, growth mediums, consumables of national production and to refuse import deliveries without decreasing quality of microbiological analysis. This approach will ensure appropriate response to occurring challenges and new biological dangers and maintenance of biosecurity of the Russian Federation at proper level.

The national growth mediums were developed for isolating and cultivating of main agents of purulent bacterial meningitis--haemophilus agar, chocolate agar, PBM-agar. The growing and selective characteristics of developed growth mediums are examined. The haemophilus agar ensures growth of Haemophilus influenzae. The chocolate agar, PBM-agar ensure growth of Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae. By growing characteristics, the national growth mediums match foreign analogues. Under application of growth mediums with selective additions it is possible to achieve selective isolation of main agents of purulent bacterial meningitis with inhibition of growth of microbes-associates.

The import substitution becomes one of strategic tasks of Russian economy as a result of imposition of economic sanctions on part of the USA, EU countries, Japan and number of other states. The development of structure and technology of production of national import substituted growth mediums permits satisfying needs of laboratory service of Russia inactive storage and to secure appropriate response to occurring challenges and new biological menaces and support bio-security of state at proper level. The presented data concerning substantiation of nomenclature of growth mediums and transport system permit satisfying in fullness the needs of clinical and sanitary microbiology in growth mediums of national production and to give up of import deliveries without decreasing of quality of microbiological studies.

The article deals with the results of comparative study of differential diagnostic characteristics of Endo growth medium of different foreign manufacturers permitted to be applied in the Russian Federation and the national Endo agar. The enhanced kit of museum test-strains and clinical material from patients were used. It is established that morphology, size and number of clumps of most enterobacteria growing in Tndo medium manufactured by Merck, Pronadisa, HiMedia and the state research center of applied microbiology and biotechnology have minor morphological differences and match the characteristics declared by manufacturers. The indicator of degree of detection (degree of inoculation) of pathogenic enterobacteria from clinical material onto Endo medium manufactured by the state research center of applied microbiology and biotechnology matched the indicators of media from foreign manufacturers. It is demonstrated that Endo growth medium manufactured by the state research center of applied microbiology and biotechnology not only is equal to import analogues but in particular cases even excels them.