Clostridium difficile - Gram-positive microorganism and the frequent causative agent of colitis associated with the use of people with broad-spectrum antibiotics. The developing imbalance of the representatives of the normal flora of the large intestine promotes reproduction of the pathogen and is accompanied by the production of protein toxins - single-chain multi-domain toxins TcdA and TcdB and binary toxin CDT. After penetration of TcdA, TcdB and CDT into eukaryotic cells by receptor-mediated endocytosis, the enzymatic domains of TcdA and TcdB modify the regulatory GTPases of the Rho family by monoglucosylation, while the A-subunit of the toxin CDT ADP-ribosylated monomeric molecules, Modification of target proteins leads to their inactivation and the development of a wide range of cellular disorders with signs of inflammatory lesions of the mucous membrane of the colon. Due to the particularly important role of toxins in the pathogenesis of differential infection, these pathogenicity factors are considered as the main components of therapeutic, preventive and diagnostic drugs. On the other hand, the use of C. difficile toxins in the scientific search tools allows obtaining fundamental data on the mechanisms of physiological and pathological processes in eukaryotic cells.

Clostridium difficile, recently renamed to Clostridioides difficile is the main cause of nosocomial diarrhea in developed nations. In recent years the appearance of so called “hypervirulent” strains like ribotype 027 (RT027) originating from North America has shaped the epidemiology in many parts of the world posing a huge burden on the healthcare system. These hypervirulent strains among others (e. g. RT017) are associated with resistance towards several antibiotics (e. g. fluoroquinolones) favoring their selection. In Europe, Israel and the American continent RT027 seems to have become the most prevalent strain, while in other parts of the world other RTs dominate. In Far East Asia, RT017 is the predominant strain, while in Australia RT014/020 and RT002 are mostly prevalent. However, for most parts of the world the C. difficile world map is rather incomplete, such as in most African countries, Middle East Asia, South Asia but also Eastern Europe including the Russian Federation. Multi-center studies are therefore needed to assess the impact of this pathogen including its molecular epidemiology and corresponding resistance.

Aim: to evaluate antagonistic properties of Lactobacilli against clinically relevant Clostridium (Clostridioides) difficile strains. Materials and methods: we assessed antagonistic properties of 21 Lactobacilli strains isolated from the patients’colon biotope against 31 clinically relevant C. difficile strains isolated from faeces of the patients with C. difficile-associated diarrhea by means of a double-step culturing in the combined cultivation system. Results: Lactobacilli strains isolated from the patients’colon biotope had selective antagonistic properties against C. difficile. Lactobacilli strains had different spectrum and intensity of antagonistic activity that showed no correlation neither with species, nor with natural population size. We isolated Lactobacilli strains with high antagonistic activity (L. paracasei 101, L. gasseri 341/2, L. paracasei 340/1). We isolated bacteriocins from Lactobacilli cultures. The influence of bacteriocins on C. difficile strains correlated with antagonistic activity of Lactobacilli; bacteriocins suppressed C. difficile growth in dose-dependent manner. Conclusion: evaluation of Lactobacilli antagonistic activity is a prospective approach to struggle against nosocomial infection caused by resistant strains, particularly using Lactobacilli autostrains for suppression of toxigenic C. difficile strains growth.

Aim. To evaluate the IgA, IgM and IgG to lipoteichoic acids (LPA) of Clostridium difficile (C. difficile) in inflammatory bowel disease (IBD). Materials and Methods. We prospectively included 147 patients with IBD [92 with ulcerative colitis (UC) and 55 with Crohn’s disease (CD)] and 30 healthy volunteers. The concentration of IgA, IgM and IgG to C. difficile LPA in blood was determined by enzyme immunoassay method. Results. The level of IgA to LPA of C. difficile was higher in active IBD - 0,12 [0,06; 0,19] mkg/ml, p<0,05) and in remission (0,12 [0,07; 0,18] mkg/ml) compared with in control group - 0,009 [0,005; 0,01] mkg/ml. In active CD the studied IgA were higher than in control group (p<0,01). The level of IgM to LPA of C. difficile was higher in IBD exacerbation (4,75 [2,48; 7,45 mkg/ml; p<0,001), in remission (4,69 [2,65; 7,85] mkg/ml; p<0,05) than in healthy volunteers (2,4 [1,5; 4,08] mkg/ml; p<0,01). The changes in UC and CD were identical. The studied IgG was higher in active IBD (4,17 [1,34; 6,55] mkg/ml; p<0,0001) and in remission (3,39 [1,42; 5,81] mkg/ml; p<0,01) than in control group (1,0 [0,89; 1,94] mkg/ml). The changes were similar in UC and CD. The levels of studied IgA and IgG in healthcare workers among our control group was higher than in the persons not related to medicine. Conclusions. The levels IgA, IgM and IgG to C. difficile LPA in IBD was significant increase compared with in healthy volunteers. The increase of antibodies was characteristic for active and inactive IBD.

Aim. Determine the etiological structure of antibiotic-associated diarrhea in Russia. Materials and methods. The study included 746 patients in inpatient treatment. 502 patients were examined at the stage of admission and discharge from the hospital, and 305 patients with the clinical picture of Clostridioides difficile-associated infection (CDI), among them 163 (46.6%) men and 142 (53.4%) women. The age of the patients was 48-67 years. All patients were examined luminal feces upon admission to the hospital, upon discharge from the hospital and in the case of a clinical picture of CDI. Results. Analysis of the etiological factor of clostridial infection showed that in 253 (83.2%) cases, the causative agent of antibiotic-associated diarrhea was C. difficile. Other types of clostridia were found in almost all CDI cases (97.7%). At the same time, C. perfringens remained the dominant type of clostridia in the same way as in patients upon admission to the clinic. The average dissemination of C. difficile was higher (p <0.05) compared with the value of the indicator in patients on admission and was 10 * 7 CFU / g; the titer of dissemination with other types of clostridia remained at the level of 10 * 5 CFU / g. - 10 * 7 CFU / g., Median 10 * 6 CFU / g. Analysis of the clinical picture of clostridial colitis revealed its similarity, regardless of the etiologically significant microorganism being detected. In 52 (16.8%) of 305 patients, the clinical picture was due to other members of the genus Clostridium (Clostridium perfringens, C. paraputrificum, C. tertium, C. novyi). Also, as with CDI, diarrhea syndrome occurred in 100% of cases, hyperthermia occurred in 82%, flatulence in 42%, vomiting in 13%, and abdominal pain in 11%. The severity of Clostridium spp. Diarrhea varied widely. So, in 26 (50%) of 52 patients with preserved anal defecation, the median stool frequency was 10 (5; 14) times / day, which is comparable with the data obtained in colitis caused by C. difficile. Conclusions. An analysis of the etiological factor in the development of CDI showed that, in addition to the known etiological factor of antibiotic-associated diarrhea - toxigenic C. difficile with the leading virulence factor production of toxin B, in 52 (16.9%) cases, other representatives of this genus were an etiological factor of diarrhea (Clostridium perfringens, C. paraputrificum, C. tertium, C. novyi). The development of antibiotic-associated diarrhea, caused by representatives of other types of clostridia, must be considered when prescribing therapy for clostridial colitis.

Aim. To study the distribution of Clostridioides difficile strains resistant to antibacterial drugs in patients with antibiotic-associated diarrhea. Materials and methods. The study included 102 strains of Clostridioides difficile, isolated from 118 patients with a clinical picture of antibiotic-associated diarrhea. Isolation and identification of microorganisms was carried out by standard bacteriological methods. Results. Of the total number of isolated strains of C. difficile, 7.6% were resistant to vancomycin and metronidazole. 21.9% of C. difficile strains were resistant to metronidazole. The level of resistance to vancomycin in strains isolated from patients with antibiotic-associated diarrhea, according to our data, has increased from 4% to 9.6% over the past 2 years. More than half of C. difficile strains (51.3%) were resistant to rifaximin. 2 strains of C. difficile were resistant to fidaxomycin. Conclusions. The analysis of C. difficile resistance to the main drugs recommended as etiotropic therapy for clostridial colitis showed that it was 9.6% for vancomycin and 21.9% for metronidazole in a Russian coloproctology hospital. The obtained data confirm the need to monitor the spread of resistance among strains of C. difficile, the etiological factor of antibiotic-associated infection.

Aim: to imply a method of Clostridium (Clostridioides) difficile-associated infection treatment based on lactobacilli autostrains. Materials and methods: Toxin-producing vancomycin-resistant C. difficile and three types of lactobacilli in different titers were isolated from the translucent feces of a patient with recurrent C. difficile-associated infection. According to the results of the study, the strain Lactobacillus zeae was detected, which showed high antagonistic activity against C. difficile. Within 48 hours, biomass of L. zeae was accumulated. The patient was administered a suspension of lactobacilli per rectum (in the form of microclysters) every other day. Results: in a patient with severe pseudomembranous colitis, a persistent remission of the underlying disease was achieved against the background of regular injections of a suspension of Lactobacillus zeae autostrains with a high antagonistic activity against C. difficile, isolated in this patient. Conclusion: Lactobacillus transplantation is an effective and promising treatment for recurrent clostridial infection resistant to antibiotic therapy.

Aim. Study of the dynamics of changes in the intestinal microbiota of patients with Clostridioides difficile-associated infection. Materials and methods. The study included 746 patients in inpatient treatment. 502 patients were examined at the stage of admission and discharge from the hospital, and 305 patients with the clinical picture of Clostridioides difficile-associated infection (CDI), among them 163 (46.6%) men and 142 (53.4%) women. The age of the patients was 48-67 years. The qualitative and quantitative composition of translucent feces was investigated. Results. Analysis of the study of the qualitative and quantitative composition of the fecal microbiota of patients treated in a coloproctology hospital and patients with a clinical picture of Clostridioides difficile-associated infection showed the dynamics of changes in the colonic microbiota in patients upon admission to hospital and the development of the clinical picture of antibiotic-associated diarrhea. Upon admission to the hospital, patients with diseases of the colon showed a decrease in the titer of lactobacilli (median 10 * 5 CFU / g., Fluctuation range 10 * 4 CFU / g; 10 * 6 CFU / g). With colitis caused by Clostridioides difficile and other members of the genus Clostridium spp., A significant decrease in the amount of lactobacillus in the luminal feces was observed (p <0.01). There were no significant differences in the level of contamination of the luminal feces with enterobacteria in all groups of patients examined. Conclusions. Development of CDI is characterized by a pronounced decrease auhtonnoy microflora, especially lactobacilli. The degree of microbiota changes in patients with CDI is ambiguous for each member of the microbial community of colonic microbiocenosis.

Aim. To assess etiologic factor of Clostridium genus associated infection and its influence on the disease clinical course. Materials and methods. 549 in-hospital patients participated in the study. We evaluated clinical and biochemical parameters of blood, stool frequency or stoma function intensity, feces volume per day and length of in-hospital stay. We performed stool sampling three times: during 48 hours after admission, in case of diarrhea and prior discharge. We evaluated glutamate-dehydrogenase (GDH) and Clostridium difficile toxins A and B by means of immunological assays. All samples underwent cultivation in anaerobic conditions. Results. Analysis of clostridial infection ethiologic factor has revealed 38 (17,9%) cases of clostridial diarrhea associated with another Clostridium species. We discovered Clostridium perfringens in 32 (84%) cases, Clostidium novyi in 5 (13%) cases and Clostidium hathewayi in 1 (3%) patient. Diarrhea severity, clinical and laboratory inflammation markers did not differ significantly depending on the isolated etiological agent of clostridial infection and its titer. Clostridial infection significantly increased in-hospital post-surgery length of stay by 4 days (p < 0,01). Conclusions. Symptoms C. difficile-associated infection could occur not only in case of persisting C. difficile but also in cases of other Clostridium species. Clinical manifestation of C. difficile-associated infection increase in-hospital stay.

Aim: to develop and to evaluate a method for Clostridium (Clostridioides) difficile antioxidant activity (AOA) assessment via chemiluminescent (CL) analysis. Materials and methods: we investigated ten C. difficile strains, obtained from patients with antibiotic-associated diarrhea that were cultured for two days. AOA was assessed on the first and second day of cultivation by means of CL assay based on 2,2’-azo-bis (2-amidinopropane) dihydrochloride-luminol system. Results: our method for AOA estimation is characterized by high reproducibility and reliability (the average coefficient of variation between parallel samples is 2.0-18.2%, the calibration curve coefficient of determination is 80.5-89.4%). C. difficile AOA after the first day of cultivation is 6.95-9.93 units; it increases to 9.86-13.27 units after the second day (p <0.01). A negative correlation (η = -0.3, p <0.05) is shown between the initial AOA level and its growth rate during cultivation. Conclusion: we propose a simple and reliable method for C. difficile AOA assessment that is suitable for routine use in clinical bacteriology. Length of C. difficile culturing is associated with increase of its AOA.

Aim of the review. To study and consolidate recent data on Clostridium (Clostridioides) difficile antibacterial resistance mechanisms. Key points. There is objective data about the spread of antimicrobial resistant Clostridium (Clostridioides) difficile strains. Mechanisms of antimicrobial resistance in bacteria determined by genetic resistance or metabolic pathways are described. Spread of antimicrobial resistance in clinically relevant С. difficile is aggravated by its ability to form biofilms. Moreover, being a spore-forming bacterium, С. difficile can resist microbicidal action staying in the form of spore. After antibiotic cessation С. difficile returns to vegetative state and causes recurrence of thee disease. Understanding of С. difficile antibacterial resistance mechanisms is one of the key points in disease prevention strategy. Besides antibiotic stewardship, monitoring for the С. difficile antibacterial resistance spread is needed. We argue that the research on С. difficile antibacterial resistance and on the development of novel antibacterial agents effective against С. difficile must be continued.

In recent decades, against the background of widespread and, often, unfounded antibiotic therapy, an increase in Clostridium difficile infection (CDI) due to hypervirulent strains has been observed. According to international CDI treatment protocols, metronidazole and vancomycin are starting therapy for patients with newly diagnosed infections, even though the likelihood of a relapse is about 65%. In addition, the increased interest in CDI is associated with the need to develop and use alternative strategies aimed at preventing and increasing the effectiveness of treatment. In this regard, we first transplanted fecal microflora for this group of patients in Russia. This alternative method of treatment removes the spores of C. difficile, replenishes the normal intestinal flora, reduces the level of vegetative forms of C. difficile in the intestines, and supports the patient’s own immune response.

Staphylococci are now the most common cause of infective endocarditis (IE). The onset of staphylococcal endocarditis (SE) is acute, with high fever, severe intoxication, and therefore, during the initial visit to the doctor, there is an erroneous assumption of influenza, meningitis, hepatitis and other acute diseases. Sometimes the cause of the development of SE remains unclear, the initial clinical manifestations are characterized by high activity of the process, severe general condition of patients, hectic fever, stunning chills, sweats, yellow staining of the skin and mucous membranes, vomiting with blood, leukocytosis, anemia. A clinical case of gastrointestinal SE debut is described with signs of hepatitis and gastric ulcer. Hemorrhages and necrosis of the mucous membrane led to the formation of erosions and ulcers in the antrum and pyloric regions of the stomach, which was manifested by the sudden appearance of severe pain in the abdomen, vomiting with blood. Gastrointestinal manifestations of necrotic vasculitis at the beginning of the SE complicated its timely diagnosis. Hemorrhagic rash was characterized by extensive lesions with the transition to necrosis or suppuration. Cerebral embolism led to multiple brain abscesses, the symptoms of which became leading in the clinical picture. Coronary emboli caused the formation of myocardial abscesses. The use of a chemotherapeutic combination of vancomycin, amikacin and rifampicin with a highly virulent pathogen was ineffective: signs of severe heart damage with perforation of the coronary valve of the aortic valve developed. Progressive multi-organ failure has been fatal.

Asthenic syndrome is characteristic of chronic gastroduodenitis, while age-related features of asthenic syndrome in HP-associated chronic gastroduodenitis are not well understood. Objective: to describe the features of asthenic syndrome in adolescents with HP-associated chronic gastroduodenitis. Materials and methods. The study of the frequency and severity of asthenic syndrome was carried out by questioning 121 patients suffering from morphologically verified chronic gastroduodenitis (children 5-12 years old, adolescents 13-17 years old, and adults 18-60 years old. adults, there were headaches, tearfulness, but less often - attention disorder. There was a positive correlation between the attention disorder and age (r = 0.81, p <0.05). Differences may be associated with egetativnoy nervous system in adolescence and with a higher frequency and vegetososudistoy ENT diseases in this age group.