This study presents a comparative analysis of microbial tolerance and physicochemical properties of HFA-E (fire-resistant hydraulic fluid, aqueous-based, emulsion type) hydraulic fluids based on commercial "Hydrotol-ITCh HFAE" and "Fimitol P87 AF" concentrates used in mining hydraulic roof support systems. Metagenomic analysis revealed distinct microbial community structures in the two fluids. The Hydrotol-ITCh HFAE-based fluid microbiota consisted predominantly of Bacteria (99.77%), especially Proteobacteria, while the Fimitol P87 AF-based fluid exhibited a more complex and taxonomically diverse community, including a significant proportion of Archaea (47.09%) and Bacteria (52.92%) from groups such as methanogens (Methanobacteriaceae) and sulfate-reducing bacteria (Desulfovibrionaceae), respectively. In vitro tests confirmed the inherent antimicrobial activity of the fluids, which significantly reduced planktonic microbial viability and eradicated the majority of bacteria. The physicochemical properties of the fluids remained stable even under high initial bacterial load, confirming their reliability during microbial contamination. However, under industrial conditions, the Hydrotol-ITCh HFAE-based fluid demonstrated lower contamination and higher emulsion stability (pH reduced to 8.5 after one year of operation versus 6.5 for "Fimitol P87 AF"), which reduced the risk of biocorrosion and the need for additional treatments. This study emphasizes the importance of comprehensive monitoring of microbial diversity and physicochemical parameters for predicting the service life of hydraulic systems, developing effective biocides, and minimizing risks to equipment and personnel. The obtained data can be used to optimize hydraulic fluid compositions and their operational strategies.

The widespread use of disinfectants and antiseptics has led to the emergence of nosocomial pathogens that are less sensitive to these agents, which in combination with multidrug resistance (MDR) can pose a significant epidemiologic risk. We investigated the susceptibility of nosocomial Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus to a 0.05% chlorhexidine (CHX) solution and a biocidal S7 composite solution based on CHX (0.07%) and benzalkonium chloride (BAC, 0.055%). The prevalence of efflux pump genes associated with biocide resistance and their relationship to antibiotic resistance was also determined. Both biocides were more effective against Gram-positive S. aureus than Gram-negative bacteria. The most resistant strains were P. aeruginosa strains, which were mainly killed by 0.0016% CHX and by 0.0000084% (CHX)/0.0000066% (BAC) S7. The S7 bactericidal effect was observed on P. aeruginosa and S. aureus after 10 min, while the bactericidal effect of CHX was only observed after 30 min. qacEΔ1 and qacE efflux pump genes were prevalent among E. coli and K. pneumoniae, while mexB was more often detected in P. aeruginosa. norA, norB, mepA, mdeA, and sepA were prevalent in S. aureus. The observed prevalence of efflux pump genes highlights the potential problem whereby the sensitivity of bacteria to biocides could decline rapidly in the future.

Iron uptake plays an important role in the persistence of Escherichia coli in the host and for its survival in the environment, and it is known that E. coli has a variety of siderophore systems for iron uptake. We investigated the ability to produce siderophores, the genetic diversity of the siderophores and their correlation with virulence-associated genes (VAGs), phylogroups and bacteriocin production in E. coli strains isolated from different sources: uropathogenic E. coli (UPEC) from urine of patients with urinary tract infections, avian pathogenic E. coli (APEC) from organs of birds with signs of colibacillosis, fecal E. coli (FEC) from feces of healthy cattle and E. coli from organic fertilizers based on poultry and cattle manure (OFEC). A high variability in siderophore production was found among the UPEC strains studied, while the OFEC strains showed the highest siderophore production among all groups. Genes for aerobactin and yersiniabactin receptors were most frequently found in the UPEC strain, followed by the APEC, FEC and OFEC strains. The greatest diversity of siderophore receptors was found in the APEC strain. We also found that iutA-positive E. coli isolated from animals contained more VAGs than iutA-negative strains. The profiles of the siderophore genes of APEC and OFEC from poultry manure were very similar, indicating that APEC can be transmitted via organic fertilizers, suggesting that poultry manure is an environmental risk. The data obtained complement the information on the prevalence of siderophore producers and contribute to our knowledge on the biodiversity of E. coli pathotypes.

Uropathogenic Escherichia coli (UPEC) is a primary cause of urinary tract infections (UTIs), with recurrent cases often linked to its ability to form biofilms. This study investigated the effects of various antibiotics on UPEC biofilm formation and the subsequent interaction of these biofilms/their supernatants with human neutrophils. We determined the minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), and biofilm eradication concentrations (MBEC) for ampicillin, gentamicin, chloramphenicol, ciprofloxacin, and levofloxacin. Our results showed an increase in MBEC compared to MBC for all tested antibiotics, confirming the enhanced antibiotic resistance of bacteria in biofilm. We found that sub-MICs of ciprofloxacin, which moderately inhibited planktonic growth, actually stimulated an increase in biofilm biomass. This antibiotic-induced biofilm growth was accompanied by changes in bacterial morphology, including the formation of elongated, filamentous cells, an adaptive stress response. Biofilm-embedded bacteria, but not their supernatants, significantly reduced neutrophil viability, primarily by inducing neutrophil necrosis. The presence of ciprofloxacin during biofilm formation did not fundamentally alter interactions with neutrophils. These findings highlight the importance of studying effects of antibiotic pressure on biofilm formation, underscoring the challenges in antibiotic treatment of UTIs.

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Agricultural production has been intensifying for a while and this has made for growing volumes of organic wastes; a part of them is later used as fertilizers. At present, more than 200 types of organic fertilizers are employed in agriculture; they differ in their origin, properties, and effects on the environment. Wastes from agricultural productions typically contain biocides, antibiotics included, and also, which is especially important, pathogens and opportunistic pathogenic microorganisms. Soil contamination with such wastes destroys natural biocenosis. Moreover, pathogens that remain in wastes due to absence of proper treatment can pose serious hazard for humans and animals. Safety of food products made of raw materials, growth of which relies on using organic fertilizers, is a significant component of the overall issue. This analytical review provides a classification and descriptions of organic fertilizers and data on production volumes and accumulation of animal husbandry wastes. It also describes major biological and chemical factors of health risks associated with using organic fertilizers as well as provides the results of up-to-date studies that focus on negative effects of organic fertilizers. Special attention is paid to literature data about negative impacts exerted on human health and the environment by organic fertilizers that contain antibiotics and salts of heavy metals. It is emphasized specifically that organic fertilizers can very often contain copper, zinc, cadmium, nickel, chromium, arsenic, lead and mercury compounds. Improper use of technologies for treatment of organic fertilizers is shown to result in microbial and chemical pollution in soils and water objects. Methods employed to assess effects of animal husbandry wastes on human health and the environment are described considering international and Russian practices and documents that establish regulatory requirements to safe use of organic fertilizers. The review establishes that a strategy for providing safety of agricultural production should consider risks for human health and include systemic monitoring over quality of the environment and population health.

Background. Infections caused by multidrug-resistant (MDR) Klebsiella pneumoniae are the leading cause of mortality worldwide. The widespread use of disinfectants and antiseptics has caused the emergence of K. pneumoniae with reduced sensitivity to them, which, in combination with MDR, can pose a significant epidemiological threat. The aim of the study was to assess the prevalence of efflux pump and transporter genes associated with biocide resistance and their association with antibiotic resistance among K. pneumoniae isolated in a cardiac surgical hospital. Materials and methods. K. pneumoniae isolates (n = 50) from the patients and medical equipment were tested by polymerase chain reaction for the presence of genes of 4 types of efflux pumps (qacEΔ1, qacE, oqxA, oqxB, acrA) and 2 transporters involved in the outflow of cations (cepA) and zinc ions (zitB). Spearman's rank correlation test was used to assess the strength of the association between the efflux pumps, beta-lactamase genes and mobile genetic elements. Results. The occurrence of K. pneumoniae containing qacEΔ1, qacE, oqxA, oqxB, acrA, cepA and zitB was high: 54, 62, 100, 84, 100, 72 и 96% respectively. K. pneumoniae with a combination of all the studied pumps was most often detected (32%), and these isolates were MDR in 100% of cases. The qacE, qacEΔ1 genes were closely associated with resistance to cephalosporins, carbapenems, fluoroquinolones, carbapenemase genes, and integrons. The results of the study showed that the genes of various efflux pumps associated with biocide resistance and their combinations were widely represented among the clinical isolates of MDR K. pneumoniae. Conclusion. The high prevalence of efflux pump genes associated with resistance to quaternary ammonium compounds, chlorhexidine and zinc salts and their significant association with antibiotic resistance in nosocomial K. pneumoniae underlines the importance of further studying the mechanisms of cross-resistance to biocides to improve methods of combating MDR nosocomial pathogens.

The use of antibiotics in agriculture and subsequent environmental pollution are associated with the emergence and spread of multidrug-resistant (MDR) bacteria including Escherichia coli. The aim of this study was to detect antimicrobial resistance, resistance genes and mobile genetic elements of 72 E. coli strains isolated from faeces of healthy farm animals. Disk diffusion test showed resistance to ampicillin (59.7%), tetracycline (48.6%), chloramphenicol (16.7%), cefoperazone and ceftriaxone (13.9%), cefepime and aztreonam (12.5%), norfloxacin and ciprofloxacin (8.3%), levofloxacin (6.9%), gentamicin and amikacin (2.8%) among the studied strains. Antibiotic resistance genes (ARGs) were detected by polymerase chain reaction: the prevalence of blaTEM was the highest (59.7% of all strains), followed by tetA (30.6%), blaCTX-M (11.1%), catA1 (9.7%), less than 5% strains contained blaSHV, cmlA, floR, qnrB, qnrS, tetM. 26.4% of E. coli strains had a MDR phenotype. MDR E. coli more often contained class 1 integrons, bacteriophages, conjugative F-like plasmids, than non-MDR strains. ARGs were successfully transferred from faecal E. coli strains into the E. coli Nissle 1917 N4i strain by conjugation. Conjugation frequencies varied from (1.0 ± 0.1) * 10-5 to (7.9 ± 2.6) * 10-4 per recipient. Monitoring mobile genetic elements of E. coli for antibiotic resistance is important for farm animal health, as well as for public health and food safety.

Objective: Multidrug-resistant, highly pathogenic Escherichia coli strains are the primary causative agents of intestinal and extraintestinal human diseases. The extensive utilization of antibiotics for farm animals has been identified as a contributing factor to the emergence and dissemination of E. coli strains that exhibit multidrug resistance and possess high pathogenic potential. Consequently, a significant research objective is to examine the genetic diversity of pathogenic E. coli strains and to identify those that may pose a threat to human health. Methods: In this study, we present the results of genome sequencing and analysis, as well as the physiological characterization of E. coli strain APEC 36, which was isolated from the liver of a broiler chicken with generalized colibacillosis. Results: We found that APEC 36 possess a number of mechanisms of antibiotic resistance, including antibiotic efflux, antibiotic inactivation, and antibiotic target alteration/replacement/protection. The most widely represented group among these mechanisms was that of antibiotic efflux. This finding is consistent with the strain’s documented resistance to multiple antibiotics. APEC 36 has an extremely rare variant of the beta-lactamase CTX-M-169. Notwithstanding the multitude of systems for interfering with foreign DNA present in the strain, seven plasmids have been identified, three of which may possess novel replication origins. Additionally, qnrS1, which confers resistance to fluoroquinolones, was found to be encoded in the genome rather than in the plasmid. This suggests that the determinants of antibiotic resistance may be captured in the genome and stably transmitted from generation to generation. Conclusions: The APEC 36 strain has genes for toxins, adhesins, protectins, and an iron uptake system. The obtained set of genetic and physiological characteristics allowed us to assume that this strain has a high pathogenic potential for humans.

Farm animals are a natural reservoir of commensal and pathogenic Escherichia coli strains with high zoonotic potential. Here, we present five complete genomes of E. coli strains isolated from healthy animals and animals with colisepticemia from farms in Russia. The strains contain diverse virulence-associated and antibiotic resistance genes and multiple plasmids.

Biofilms as a form of adaptation are beneficial for bacterial survival and may be hot spots for horizontal gene transfer, including conjugation. The aim of this research was to characterize the biofilm biomass, viable cell ratios and conjugative transfer of the pOX38 plasmid, an F-plasmid derivative, from the Escherichia coli N4i pOX38 strain (donor) into a uropathogenic E. coli DL82 strain (recipient) within dual-species biofilms with one of the following opportunistic pathogenic bacteria: Klebsiella pneumoniae, Enterococcus faecalis or Pseudomonas aeruginosa. Dual-species biofilms of E. coli with K. pneumoniae or P. aeruginosa but not E. faecalis were more massive and possessed more exopolysaccharide matrix compared to single-species biofilms of donor and recipient cells. Correlation between biofilm biomass and exopolysaccharide matrix was rs = 0.888 in dual-species biofilms. In dual-species biofilm with E. faecalis the proportion of E. coli was the highest, while in the biofilm with P. aeruginosa and K. pneumoniae, the E. coli was less abundant. The conjugative frequencies of plasmid transfer in dual-species biofilms of E. coli with E. faecalis and P. aeruginosa were reduced. A decrease in conjugative frequency was also observed when cell-free supernatants (CFSs) of E. faecalis and P. aeruginosa were added to the E. coli conjugation mixture. Further, the activity of the autoinducer AI-2 in the CFSs of the E. coli conjugation mixture was reduced when bacteria or CFSs of E. faecalis and P. aeruginosa were added to the E. coli conjugation mixture. Hence, the intercellular and interspecies interactions in dual-species biofilms depend on the partners involved.

OBJECTIVE:To improve perioperative algorithm of prevention of complications in patients with ventral and incisional hernias via differentiated choice of mesh implants and hernia repair technique.MATERIAL AND METHODS:The study included 144 patients with abdominal wall hernia, who were divided into two representative groups.RESULTS:Original algorithms for choosing the method of hernia repair depending on type and position of mesh implant, as well as methods of perioperative prevention of complications are proposed.CONCLUSION:These algorithms significantly reduced the incidence of postoperative wound complications after sublay hernia repair and posterior separation with TAR.

Commensal bacteriocin-producing Escherichia coli are of interest for possible use as probiotics to selectively control the spread of pathogenic bacteria. Here, we evaluated the biosafety and efficacy of two new bacteriocin-producing E. coli strains, Q5 (VKM B-3706D) and C41 (VKM B-3707D), isolated from healthy farm animals. The genomes of both strains were sequenced, and genes responsible for the antagonistic and colonization abilities of each strain were identified. In vitro studies have shown that both strains were medium-adhesive and demonstrated antagonistic activity against most enteropathogens tested. Oral administration of 5 × 108 to 5 × 1010 colony-forming units of both strains to rats with drinking water did not cause any disease symptoms or side effects. Short-term (5 days) oral administration of both strains protected rats from colonization and pathogenic effects of a toxigenic beta-lactam-resistant strain of E. coli C55 and helped preserve intestinal homeostasis. Taken together, these in silico, in vitro, and in vivo data indicate that both strains (and especially E. coli Q5) can be potentially used for the prevention of colibacillosis in farm animals.

Microbial contamination means that infectious agents are identified on objects in the hospital environment. This serious issue is the most significant for healthcare organizations. Covering abiotic surfaces with a thin polymer film can be a promising way to fight against microbial adhesion and colonization. This film acts as a depot of an antibacterial substance. In this study, our aim was to investigate antimicrobial effects of new water compositions of polyacrylamides (PAM) with CuSO4 and ZnSO4. We examined antibacterial activity of 5%-solutions of CuSO4 and ZnSO4 and their compositions with various PAM types in a concentration equal to 0.075 % against such reference cultures as Escherichia coli, Klebsiella pneumoniaе, Pseudomonas aeruginosa, and Staphylococcus aureus. We estimated use of PAM as a growth substrate as well as antimicrobial activity of the analyzed solutions and compositions in agar and liquid nutrient media. As a result, we established that bacterial cultures did not use PAM as sole nutrition source when growing in a liquid mineral medium and on PAM-films covering glass and plastic surfaces. More apparent inhibitory effects were produced on microorganisms cultivated on solid and liquid nutrient media by 5%-solution of ZnSO4. When PAM Praestol 857 and PAM Praestol were added to solutions of Cu2+ and Zn2+ cations, it resulted in an authentic increase in a diameter of a zone with inhibited bacterial growth in the agar medium. In the liquid medium, salts of both metals inhibited the growth and viability of all the analyzed microorganisms already in a concentration equal to 0.16 % or lower. Adding PAM Praestol 2530 led to a slight decrease in antibacterial efficiency of the examined metal salts whereas PAM Praestol 857 had practically no influence on bacteriostatic and bactericidal effects produced by them. Therefore, use of the obtained composite solutions where CuSO4 or ZnSO4, immobilized on a PAM matrix act as an antibacterial component seems a promising way to disinfect objects in the hospital environment. This can significantly reduce risks of hospital-acquired infections.

Strains of various bacterial species and their products, which are involved in the decomposition of complex substances, are used for the formation and maintenance of a balanced host’s gut microbiota. The biological properties (bacterial cell surface hydrophobicity, adhesion, antagonistic activity towards other strains and resistance to biological fluids) of two Escherichia coli strains, LEGM-18 (a natural strain, isolated from a healthy person) and ŽP (a genetically modified Nissle 1917 strain that harbors a conjugative plasmid with the ColE7 bacteriocin gene) were studied. The cell surface hydrophobicity of both investigated strains was relatively low. In the adhesion assays, the LEGM-18 strain exhibited a moderate adhesion to human erythrocytes, while the ŽP exhibited low adhesion. Both strains had significant antagonistic effect against E. coli O157, E. coli 643 and Shigella flexneri. LEGM-18, as well as ŽP, were resistant to pepsin and bile action. The data obtained indicate that LEGM-18 and ŽP have potential as new veterinary probiotics.

Cattle are a reservoir of pathogenic and potentially pathogenic Escherichia coli ( E. coli ) strains, which can pose a threat to human and animal health. The aim of the study was to evaluate the occurrence of 22 virulence-associated genes (VAGs), as well as the prevalence of antimicrobial drug resistance and three different bla -genes among 49 E. coli strains isolated from healthy cattle. The presence of VAGs that are common among diarrheagenic E. coli (DEC) strains and/or extraintestinal pathogenic E. coli (ExPEC) strains was determined by amplifying specific gene sequences by PCR. The following VAGs associated with DEC were found: east1 in 24.5 % of the studied E. coli strains, estI in 10.2 %, ehxA in 8.2 %, stx2 in 6.1 %, eltA in 4.1 %, estII and stx1 in 2.0 % of the studied strains. The prevalence of ExPEC VAGs was: fimH – 91.8 %, afa/draBC – 61.2 %, iutA – 44.9 %, flu – 32.7 %, sfaDE and hlyF – 30.6 %, iroN – 22.4 %, ompT and papC – 20.4 %, kpsMTII and hlyA – 18.4 %, iss – 14.3 %, usp – 2.0 %, cnf1 and iha were not detected among the studied strains. Based on the found co-occurrence of VAGs “classical”, hetero-pathogenic and hybrid-pathogenic E. coli strains were found. E. coli strains isolated from cows had a higher diarrheagenic potential, whereas E. coli strains isolated from calves more frequently contained genes associated with the ExPEC pathotype. Among the studied E. coli strains, 77.6 % were resistant to ampicillin, 49.0 % to tetracycline, 20.4 % to chloramphenicol, 16.3 % to cefoperazone, 16.3 % to ceftriaxone, 16.3 % to aztreonam, 14.3 % to cefepime, 10.2 % to norfloxacin, 10.2 % to ciprofloxacin, 6.1 % to levofloxacin and 2.0 % to gentamicin. All strains were sensitive to meropenem and amikacin. 32.7 % of the studied E. coli strains were found to be multidrug resistant, as they were resistant to at least three groups of antibiotics. With PCR, the bla TEM , bla SHV , and bla CTX-M genes were detected in 100, 31.6, and 26.3 %, respectively, of strains resistant to at least one of the beta-lactam antibiotics. Thus, it was shown that the studied faecal E. coli of healthy cows and calves had a high hetero-pathogenic potential, therefore in the future molecular genetic characterization of these bacteria shall be an important part of the epizootic monitoring.

Due to the spread of antibiotic-resistant bacteria, new alternatives to antibiotics and ways to prevent infections are being sought. Bacteriocin-producing bacteria are therefore attracting attention due to their probiotic potential as a safe alternative to antimicrobial drugs. The aim of this work was to determine the prevalence of bacteriocin-encoded genes among Escherichia coli strains from healthy farm animals and to characterize the presence of virulence-associated genes, the possibility of prophage induction, and hemolytic and bacterial antagonistic activity of the bacteriocin-producing E. coli in order to reveal their potential for application. It was found that 17 of 72 E. coli strains (23.6%) produced bacteriocins. Among them, 18 out of 30 bacteriocin genes were detected: the most prevalent genes were those for microcin M (58.8%), colicin E1 (52.9%), and colicin M (35.3%). Colicin Ia (29.4%), colicin E9, colicin Ib, colicin B (23.5%), and colicin E9 (17.7%) genes were also frequent, while the prevalence of genes encoding microcins V, B17, and H47 and colicins E3, K, N, U, Y, 5, and 10 did not exceed 11.8%. At least two different bacteriocin genes were detected in all 17 bacteriocinogenic strains; the highest number of different bacteriocin genes detected in one strain was seven genes. E. coli strains with combinations of colicin E1 and E or microcin M and colicin E1 genes were more prevalent than others (17.7%). Among the 17 bacteriocin-producing E. coli strains, 5.9% were hemolytic, 47.1% contained prophages, and 58.8% carried genes encoding toxins. Cell-free supernatants of bacteriocin-producing strains were shown to inhibit the growth of pathogenic E. coli strains belonging to the APEC, STEC, and ETEC pathotypes. Thus, among the studied bacteriocin-producing E. coli isolated from the gastrointestinal tract of farm animals, three strains with high antagonistic bacterial activity and the absence of pathogenicity genes, prophages, and hemolytic activity were identified and therefore have potential for application.

The increasing prevalence of antimicrobial resistant Enterobacteriaceae in poultry farm complexes is a serious problem, hence new treatment strategies and antimicrobial agents are searched for, among them probiotics. Genetically modified strains of Escherichia coli carrying conjugative plasmids with bacteriocin genes are a novel possibility of preventing and treating infections caused by antimicrobial resistant microorganisms. Two “kill”-“anti-kill” systems based on the bacteriocin colicin E7, a conjugative plasmid (pOX38 or R6K) and the E. coli Nissle 1917 strain were constructed and used in conjugation assays. In our assays, it was shown that direct delivery of the colicin E7 gene to the target bacterial cells via conjugation was efficient in killing the target cells. Based on the obtained results, it can be assumed that such systems have the prospect of being used as a new generation of probiotics and a possible alternative to antibiotics.

Conjugation is recognized as a mechanism driving dissemination of antibacterial resistances and virulence factors among bacteria. In the presented work conjugative transfer frequency into clinical uropathogenic Escherichia coli strains (UPEC) isolated from patients with symptomatic urinary tract infections was investigated. From 93 obtained UPEC strains only 29 were suitable for conjugation experiments with the plasmid pOX38, a well-known F-plasmid derivative. The study was focused on comparison of conjugation frequencies in plankton and biofilm, including comparison of conjugation frequencies in high and low biofilm biomass with their virulence potential. It was shown that the conjugation frequency depended on the biofilm biomass and was significantly higher in thin (OD580 < 0.3) than in thick biofilm (OD580 ≥ 0.3). Nonmetric multidimensional scaling analysis revealed that higher conjugation frequencies in plankton and biofilm were directly positively correlated with the sum of virulence-associated genes of the recipient strain and presence of multidrug antibiotic resistances. On the other hand, the sum of insensitivities to different bacteriocins was negatively correlated with an increase in the conjugative transfer level. Our results obtained hence indicate that the evolution of potentially more pathogenic strains via conjugation is depended on the strains' ability to be a "good" recipient in the conjugative transfer, possibly due to the ability to form thinner biofilms.

The biofilm formation by uropathogenic E. coli (UPEC) allows bacteria to avoid the influence of the host immune system that determines the pathogenesis of persistent urinary tract infections. The purpose of this work was to evaluate the mutual influence of neutrophils and biofilms formed by UPEC with different set of virulence-associated genes (VAGs). E. coli R11 and R32 strains with a wide range of virulence factors were characterized by low biofilm biomass that did not change after interaction with neutrophils. The biomass index decreased after interaction with neutrophils for strains with a limited set of pathogenicity factors (R33, R36, R45, and R44) and a "thick" biofilm. Bacterial cells and biofilm supernatants of all UPEC strains reduced viability (DiOC6(3)+/PI-) and stimulated early apoptosis (DiOC6(3)-/PI-) of neutrophils. The number of viable neutrophils was higher, while the number of apoptotic and necrotic (DiOC6(3)-/PI+) cells was lower under the action of supernatants of strains R44, R36, R45 in comparison with bacterial cells. Thus, modulation of the innate cell functions depends on the realization of the pathogenic potential of UPEC bacteria in urinary tract biofilms that determines the development of recurrent urinary tract infections.