Disco-diffusion Method Research Articles

Study of the sensitivity of methicillin-resistant <i>Staphylococcus aureus</i> to antibiotics and bacteriophage preparations

Objective. To evaluate the sensitivity of methicillin-resistant Staphylococcus aureus strains to antibiotics and therapeutic and prophylactic preparations of bacteriophages. Materials and methods. The antibiotic sensitivity of strains of methicillin-resistant S.aureus was studied by the disco-diffusion method, the determination of the minimum inhibitory concentrations of vancomycin and linezolid by broth microdilution method, and ceftaroline by E-tests. The sensitivity of methicillin-resistant S.aureus to bacteriophage preparations was studied. Results. It has been established that linezolid and vancomycin are quite active drugs against methicillin-resistant S.aureus (MRSA), however, resistance to them begins to develop. MRSA resistance to fluoroquinolones and cefoxitin was the highest of all antibiotics tested; the results obtained with cefoxitin can be interpreted for other cephalosporins (except ceftaroline) and all penicillins. Only 67.9% of MRSA strains retained sensitivity to ceftaroline, but ceftaroline-resistant strains had low levels of minimal inhibitory concentration. The preparations of the bacteriophages “Sextaphage” and “Piobacteriophage Phagio” showed their lytic activity only in relation to 35.8% and 18.9% of MRSA isolates, respectively. Conclusion. Monitoring the development of antibiotic resistance in methicillin-resistant S.aureus is an important part of the strategy of rational antibiotic therapy for staphylococcal infections. Only taking into account the preliminary step-by-step determination of the phage sensitivity of the causative agent of the disease, bacteriophage preparations can be considered as a completely possible alternative to antibiotics for the treatment of purulent inflammatory diseases caused by MRSA.

Antibiotic resistance and phage sensitivity of topical listeriosis pathogens

Relevance. The problem of listeriosis infection continues to be relevant in epizootology and epidemiology. Resistance to eradication of Listeria spp. due to the ability of the bacterium to adapt and persist in various environments, as well as its intracellular location and weak intracellular diffusion of some antibiotics. Listeriosis refers to saprozoonoses, listeria often seed food products. As a pathogen of animal origin, Listeria is of concern not only from the point of view of public health and biosafety of products, but also as a causative agent of animal disease, leading to serious economic losses. The haphazard use of antibiotics to combat listeriosis has led to a change in the background of drug sensitivity. The aim of the work was to determine the antibiotic resistance of topical listeria strains and their sensitivity to bacteriophages to substantiate the prospects of phage treatments in the fight against listeriosis infection.Methods. The methodology is based on routine bacteriological studies, spot tests and sensitivity determination by the disco-diffusion method with 132 Listeria spp pathogens.Results. Multiple antibiotic resistance to fosfomycin, meropenem, cefotaxime, bacitracin, tylosin, cephalexin, polymyxin-B, lincomycin, benzylpenicillin, cefpirom, cefaclor and other drugs was noted. Listeria phagolysis was established by bacteriophages of our collection Lm1 (97.70%), Lm2 (96.20%). These bacteriophages are deposited in the collection of the Federal Scientific Centre VIEV. Thus, the aim of the study was to expand knowledge about listeriosis bacteriophages and their use as an effective method of prevention, treatment and control of listeriosis infections in the food and livestock industry.

The prevalence of antibiotic resistance genes of carbopenemases of the metallo-β-lactamase group in enterobacteria strains isolated from patients of a multidisciplinary hospital in a region with a developed petrochemical industry

The research work included strains of Klebsiella pneumonaie (n = 128) isolated from patients of a multidisciplinary hospital in a large industrial city. The antibiotic sensitivity of the isolated pure cultures was studied in relation to the most popular antibacterial drugs in clinical practice (in the amount of 21), by the standard disco-diffusion method. Identification of resistance genes was carried out by PCR using commercial reagent kits «AmpliSens MDR-MBL-FL», «AmpliSens MDR-KPC/OXA-48‑FL». The results of determining the sensitivity of isolates isolated from the lower respiratory tract revealed low activity of amoxicillin/clavulanic acid, cephalosparins of the III and IV generation (ceftazidim, cefotaxime, cefepim). 86.7 % of isolates are resistant to the aminoglycoside group — amikacin, and 100 % are resistant to gentamicin. Meropenem was the most active of the carbapenem group — 26.6 %, about 7 % are sensitive to ertapenem. From the group of fluoroquinolones, the sensitivity varied from 20 to 30 %. The greatest activity of all drugs was shown by ticarcillin / clavulanate — 33.3 %. A high proportion of strains of Kl. pneumoniae with a phenotype of multiple resistance has been established. The identification of resistance genes made it possible to establish their diversity in antibiotic-resistant isolates, a high proportion (26.6 %) of multi-resistant strains with the absence of the studied genes, and the combination of VIM + NDM + OXA-48 genes, identified in every second studied strain, prevails. Thus, the analysis of the prevalence of antibiotic resistance genes of carbopenemases of the metallo- β-lactamase group in enterobacteria strains isolated from patients of a multidisciplinary hospital in a region with a developed petrochemical industry showed the predominance of isolates (53.9 %) with the production of a combination of three antibiotic resistance genes (VIM + NDM + OXA-48). Isolates containing two genes simultaneously (NDM + OXA-48 and VIM + OXA-48) identified in 7.8 and 6.3 %. Isolates containing a single gene (carbapenemase Kl. Pneumoniae) amounted to 5.4 %.

Profile of antibiotic resistance of Staphylococcus aureus isolated from patients and bacterial carriers of the Astrakhan region as the basis for the selection of bacteriophage producing strains for further combined phage therapy

Staphylococcus aureus has a high level of antibiotic resistance and is a common cause of nosocomial infections, which primarily requires development of new therapeutic strategies.Aim of the study was to investigate the level and spectrum of antibiotic resistance of S. aureus isolates for further isolation of virulent bacteriophages.Material and methods. The study used samples of clinical material obtained on the basis of the City Clinical Hospital No. 3 named after S.M. Kirov (Astrakhan). Bacterial strains isolated from patients were identified on the basis of morphological, cultural, biochemical and molecular genetic characteristics. The determination of the resistance of the isolated cultures was carried out by the disco-diffusion method using standardized commercial discs with antibiotics, in accordance with the guidelines.Results. Evaluation of antibiotic resistance of Staphylococcus aureus isolated during the study of clinical material from patients and analysis of sensitivity level of isolated strains of S. aureus allow us to conclude that all S. aureus isolated from patients are resistant to at least one antibiotic, and most strains are characterized by multidrug resistance to antibiotics.Conclusions. The presence of multi-resistant strains indicates the need to search for new approaches in the treatment of staphylococcal infection and to develop effective means for combination therapy based on virulent staphylococcal bacteriophages.

The results of studying the contents of the uterus in endometritis of cows

The etiological factor in the occurrence of endometritis should be considered pathogenic and conditionally pathogenic microflora that penetrates into the uterus if the rules of asepsis and antiseptics are not followed. Bacterial contamination of the uterine cavity occurs more often in cows after calving or artificial insemination. The presence of clinical endometritis depends on the balance between microbes, the body’s resistance and a number of other factors. To study the uterine contents in endometritis in cows, the samples of N.A. Flegmatov, V.S. were used. Dyudenko and Katerinova, as well as the species composition of microorganisms and their sensitivity to antibiotics were determined by the disco diffusion method. The results of the research showed that the microflora of the contents of the uterus is mainly represented by bacteria of the E. coli group, opportunistic microflora and pathogenic fungi more sensitive to ciprofloxacin and levofloxacin.

Устойчивость к противомикробным препаратам изолятов Staphylococcus aureus, выделенных из пищевой продукции на территории республики Казахстан

Foodborne diseases are the serious public health problem. One of the most common food pathogens in the world is Staphylococcus aureus, which is second only to salmonellosis in terms of the frequency of cases. Materials and methods. We studied 146 antimicrobial-resistant S. aureus isolates isolated from ready-to-eat (RTE) food products in the territory of the Republic of Kazakhstan from 2018 to 2019 and from 2021 to 2022. The taxonomic position of the bacteria was identified by MALDI-TOF mass spectrometry. The phenotypic sensitivity of bacteria was determined to 45 antimicrobial drugs by the method of minimum suppressive concentration (MSC) and the disco diffusion method (DDM). Antimicrobial resistance genes in S. aureus multidrug-resistant isolates (MDR) were determined using genome-wide sequencing (WGS). Results. The comprehensive study of the profile of antibiotic sensitivity of S. aureus food isolates was conducted, in which phenotypic sensitivity to antibiotics and the presence of resistance determinants were characterized. As far as we know, this is the first epidemiological study of S. aureus cultures of food origin using WGS in the territory of the Republic of Kazakhstan. The results revealed that the studied S. aureus isolates belong to seven different sequence types based on multilocus sequence typing (MLST), with the predominance of sequence type ST22. The studied isolates may pose a threat to public health, since 33% of S. aureus isolates were resistant to methicillin (MRSA), and the mecA gene associated with a high level of nosocomial MRSA infections was found in 45% of S. aureus isolates. Conclusion. Since food products represent one of the key routes of transmission and distribution of resistance genes, it is necessary to further monitor food products and food raw materials for the presence of antimicrobial-resistant Staphylococcus spp. Key words: Staphylococcus aureus, antimicrobial resistance, WGS

Prediction of antimicrobial activity of a food peptide and evaluation of its effectiveness in vitro

Food antimicrobial peptides are increasingly relevant in the treatment of bacterial infections and have a number of advantages in comparison with drugs: slower emergence of resistance in bacterial strains, high activity against antibiotic films and immunomodulatory properties. The physico-chemical properties causing antimicrobial properties include: cationic charge, hydrophobicity, molecular weight and amino acid sequence. Promising sources of antimicrobial peptides are milk proteins, in particular, cow colostrum proteins. The aim of the work is to extract a peptide from the pepsin hydrolysate of cow colostrum, predict its antimicrobial activity using a bioinformatic approach and confirm its effectiveness in vitro. The molecular mass distribution of the peptide was evaluated by mass spectrometric method. The analysis of mass spectra was carried out using the Mascot program, the Peptide Fingerprint option – using the Protein NCBI database. Microsequencing was performed using a MiSeq sequencer. Modeling of the spatial structure of the isolated peptide was carried out using the Schrodinger Maestro molecular modeling program. The antimicrobial activity of the peptide was studied by the disco-diffusion method on gram-positive and gram-negative bacteria. The peptide has been isolated from the pepsin hydrolysate of cow colostrum, which is absent in the known proteomic bases Protein NCBI and AVPdb and, accordingly, its biological activity and functions have not been studied. The resulting peptide belongs to linear alpha-helical peptides consists of 11 amino acid sequences ANRKLRANKSR with a molecular weight of 8.2 kDa, an isoelectric point at 12.79, a charge of +5 (cationic), hydrophilicity (hydrophobicity) +20.84 Kcal*mol-1. As a result of in vitro studies, it was found that the isolated peptide has antimicrobial activity against E. coli ATCC 25922 and B. subtilis and antimicrobial action against C. albicans.

To study the sensitivity of field strains of <i>Str. agalactiae</i> and <i>Str. uberis </i>— causative agents of cow mastitis to a drug based on marbofloxacin

An increase in the number of resistant strains of mastitis pathogens Str. agalactiae and Str. uberis is one of the causes of massive subclinical and clinical mastitis in cows. The aim of the study was to study the sensitivity of field strains of Str. Agalactiae and Str. uberis to the drug based on marbofloxacin «Marboflocin 10%» (LLC «AleksAnn»), as well as to a number of the most commonly used antibacterial drugs (ABP). Sensitivity to marbofloxacin was determined by the method of serial dilutions, to other antibacterial drugs — by the disco-diffusion method. 15 samples of breast secretions from cows with a clinical form of mastitis were examined, from which 15 cultures of streptococci were isolated, including Str. agalactiae and Str. uberis — in 53.3% of the samples. All isolated cultures of Str. Agalactiae and Str. uberis were susceptible to marbofloxacin. The mean value of the minimum inhibitory concentration (MIC) of marbofloxacin for cultures of Str. uberis is 0.50 µg/ml, and for Str. agalactiae — 0.44 ± 0.13 µg/ml. To other antibacterial drugs, the studied cultures of Str. uberis and Str. agalactiae showed different sensitivity, resistance to amoxicillin was revealed, incl. with clavulanic acid, tylosin

Antibiotic Sensitivity of Escherichia Coli Museum Strains After Long-Term Storage in a Lyophilized State at Moderately Low Temperatures

Sensitivity of microbial cultures to antibiotics was determined using disco-diffusion method, broth serial dilution and agar serial dilution. Restored viability and detection of antibiotic resistance in the museum Escherichia coli strains stored for a lasting time in a lyophilized state indicates that freeze-drying in combination with moderately low temperatures for subsequent long-term storage is an eff ective method of maintaining collection microorganism strains in a functionally stable state, including preservation of their antibiotic resistance. It was found that one of the 21 studied strains was resistant to ampicillin, ampicillin-sulbactam, cephalosporins of the I–III generations, two strains were resistant to chloramphenicol, and four strains were insensitive to tetracycline. Detection of the resistance to cephalosporins and protected penicillins in E. coli strain isolated in 1963, long before the discovery and use of these antibiotics in clinical practice, confirms that antibiotic resistance is a phenomenon associated rather with the general mechanisms of adaptation of pathogens to adverse external environmental factors than with the widespread use of antimicrobial drugs.

Analysis of the structure of bacteremia and sensitivity to antibiotics of microorganisms isolated in intensive care units in an emergency hospital in the period from 2003 to 2021: a retrospective observational study

INTRODUCTION: Creation of protocols for effective empiric antimicrobial therapy is impossible without the analysis of current antibiotic susceptibility data. OBJECTIVE: Analysis of changes in the etiological significance of the leading pathogens of bacteremia in the ICU (intensive care unit) in the period from 2003 to 2021, and their sensitivity to antibiotics; study of the types of carbapenemases in the most relevant pathogens — Klebsiella pneumoniae and Acinetobacter baumannii. MATERIALS AND METHODS: The analysis included all microorganisms isolated from the blood of patients who were in the medical 12-bed ICU in the emergency hospital of Moscow in the period from 2003 to 2021. Identification of microorganisms and determination of antibiotic sensitivity were carried out with an automatic PHOENIX analyzer and a standardized disco diffusion method. Detection of carbapenemases was carried out by PCR (polymerase chain reaction). RESULTS: In the period from 2003 to 2021, 17 034 blood samples were examined, from which 6372 microorganisms were isolated. During this period, the proportion of Gram-negative microorganisms increased from 21.0 to 52.8 %, mainly due to K. pneumoniae from 1.0 to 24.5 % and A. baumannii from 0 to 9.1 %. The resistance of these microorganisms to carbapenems increased significantly from 2008 to 2021: K. pneumoniae from 2.3 % to 70.3 %, A. baumannii — from 7.5 to 99.5 %. K. pneumoniae produced the following types of carbapenemases: OXA-48 (73.8 %), KPC (6.2 %), NDM 1.5 %, NDM + OXA-48 (15.4 %), KPC + OXA-48 (3.1 %). All A. baumannii strains produced OXA-40 type carbapenemase. OXA-48 carbapenemase producers were resistant to colistin and tigecycline in 14.6 and 44.8 %, and to ceftazidime/avibactam in 4.2 %. CONCLUSIONS: The increased level of antimicrobial resistance in recent years among Gram-negative microorganisms isolated from blood is a very significant problem in the ICU. Most K. pneumoniae strains are characterized as multi-drug resistant, about 10 % of the strains were categorized as extremely-drug resistant (XDR) or pan-drug resistant. All strains of A. baumannii belong to the category of XDR.

Sensitivity of microbiota of bioaerosol and surfaces of boxes for holding animals in veterinary clinics to antimicrobial drugs

The formation of antibiotic resistance in microorganisms in veterinary medicine clinics is considered a severe problem not only for veterinary medicine but also for the public because the circulating microflora contaminates the clinic's environment and the veterinary staff, patients' animals, their owners, and their homes. The work aimed to determine the sensitivity of microorganisms isolated from bioaerosol and the surfaces of boxes for keeping animals in veterinary clinics to antimicrobial drugs. Collection of washings from the inner surfaces of the boxes was carried out with the help of disposable sterile tampons of industrial production with an average area of 100 cm2. Identification of isolated microorganisms was carried out according to morphological, cultural, biochemical properties, and signs of pathogenicity, which are described in Bergey's identifier of bacteria. The sensitivity of bacteria to antibiotics was performed on the Muller-Hinton medium according to the classical Bauer-Kirbi disco-diffusion method. It was established that gram-positive bacteria isolated from bioaerosol and the surface of boxes for keeping sick animals in veterinary clinics were sensitive in 66.7–100 % of cases to antibiotics used in these clinics. At the same time, the high bactericidal activity of antimicrobial drugs of the groups: cephalosporins, fluoroquinolones, and nitrofurans was found. Since the sensitivity of Acinetobacter baumani, Enterobacter spp., Escherichia coli, and Pseudomonas aeruginosa was from 80 to 100 % of the cultures tested. In addition, antibiotics of the penicillin series, macrolides, and azalides, practically did not act on these bacteria because they naturally resisted them. Therefore, to effectively use antimicrobial drugs to treat chronic infections, it is necessary to determine the sensitivity of the isolated microflora. Therefore, based on the study results, it can be concluded that in veterinary clinics, bioaerosols, and equipment, the pathogens of nosocomial infections of gram-negative and gram-positive bacteria resistant to antimicrobial drugs may circulate, provided that antibiotics are prescribed without determining their sensitivity to antibiotics.

Изучение биологических свойств и антибиотикорезистентности пробиотических бактерий из Кореи и Японии

The scope of the study is to study the biological properties of dietary supplements line: LactoBalance multiprobiotic, Neobiotic Lactobalance and Neobiotic Lactobalance Baby/Lactobalance Baby, isolation and generic identification of probiotic microorganisms from samples, confirmation of their growth properties and study of their antibiotic resistance. Materials and methods. The study confirmed that the number of probiotic microorganisms in the Lactobalance product line corresponds to those declared by the manufacturer. From biologically active food additives, probiotic microorganisms were isolated, identified and classified according to GOST R 56139-2014, MU 2.3.2.2789-10 [6, 7] and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). Isolation and cultivation of bifidobacteria strains and thermophilic streptococcus were carried out on a nutrient medium for the cultivation and isolation of bifidobacteria (FBSI SSC PMB, Obolensk, Russia), lactobacilli strains – on a nutrient medium MRS (HiMedia Laboratories Pvt. Limited, India). The growth properties of isolated probiotic microorganisms were studied by passaging them on nutrient media and their resistance to the most clinically significant antibiotics (Amoxicillin + clavulanic acid, Cefixime, Ciprofloxacin, Azithromycin, Clarithromycin, Levofloxacin, Oxacillin) and to the antiprotozoal and antimicrobial substance Metronidazole was determined using 2 methods: disco-diffusion method (DDM) and minimum inhibitory concentration (MIC) using strips. The studies used antibiotic discs and MIC strips manufactured by HiMedia Laboratories Pvt. Limited (India), Liofilchem srl. (Italy). Results. From the studied samples of dietary supplements, probiotic bacteria were isolated and identified (11 strains of bifidobacteria, 7 strains of lactobacilli and 1 strain of thermophilic streptococcus, which corresponds to those declared by the manufacturers). The number of living probiotic microorganisms was determined and their growth properties were confirmed. When studying the bacteria included in Lactobalance, almost all isolated strains and, in general, consortia of bacteria had resistance or low natural sensitivity to cefixime and ciprofloxacin, oxacillin. All lactobacilli were naturally resistant to metronidazole. Among bifidobacteria, the B. longum strain was resistant to metronidazole. All bacteria were highly sensitive to levofloxacin, amoxicillin with clavulanic acid, azithromycin and clarithromycin. As part of Neobiotic Lactobalance and Neobiotic Lactobalance Baby/Lactobalance Baby, 84% of the isolated bacteria, as well as the consortium of bacteria, were resistant or had low sensitivity to ciprofloxacin, cefixime, metronidazole and oxacillin. B. bifidum was resistant to azithromycin and clarithromycin. All isolated bacteria showed sensitivity to amoxicillin with clavulanic acid and levofloxacin, but the consortium of bifidobacteria showed high sensitivity only to amoxicillin with clavulanic acid. The decrease in sensitivity to other antibiotics is associated with the synergy of the properties of individual strains. Conclusion. Based on the results of in vitro studies, it can be concluded that the probiotic bacteria included in the Lactobalance dietary supplement line correspond to the declared species and their quantity and retain their growth properties. When taking all dietary supplements in the Lactobalance line while taking antibiotic therapy with cefixime, ciprofloxacin and oxacillin, as well as taking metronidazole, there is a possibility of colonization of the intestinal mucosa with probiotic strains included in their composition. When taking Neobiotic Lactobalance and Neobiotic Lactobalance Baby/Lactobalance Baby, there is a possibility of colonization of the intestinal mucosa with probiotic strains while taking cefixime, metronidazole, ciprofloxacin, oxacillin, azithromycin and clarithromycin. Key words: probiotics, bifidobacteria, lactobacilli, thermophilic streptococcus, natural antibiotic resistance, minimum inhibitory concentration of antimicrobial drugs

ОБОСНОВАНИЕ АНТИБАКТЕРИАЛЬНОЙ ХИМИОТЕРАПИИ В ПАРОДОНТОЛОГИИ НА ОСНОВАНИИ ОЦЕНКИ АНТИБИОТИКОРЕЗИСТЕНТНОСТИ ПО ДАННЫМ РАЗНЫХ МЕТОДОВ ИССЛЕДОВАНИЯ

The aim of the study was to establish the prevalence of strains of microorganisms resistant to antibacterial drugs isolated from subgingival dental plaques of periodontitis patients in the acute and remission stages. Materials and methods of research։ For the study, were recruited 90 patients who were diagnosed with chronic periodontitis (K05.3) because of clinical examination and subsequent treatment. The research methods included culture (disco-diffusion method) and molecular biological technologies (PCR), which allows identifying resistant strains of bacteria isolated from subgingival biofilm. Results։ Our results confirm that periodontopathogenic anaerobic bacteria, in contrast to sanitary-significant microbes of the ESCAPE pathogen group, were not found to be resistant to doxycycline and ciprofloxacin in the phenotypic test (disk method). The data obtained regarding the detection of genetic markers of resistance to betalactam antibiotics are generally consistent with the results of studies obtained in Western Europe (Spain, Italy, Greece). At the same time, in relation to genetic markers of resistance to tetracyclines and fluoroquinolones, significantly lower levels of detection of resistant strains were established than in studies by foreign authors. Perhaps this is due to the widespread use of these drugs in these years. On the other hand, closer results for tetracycline and fluoroquinolone resistance markers are from researchers in the People's Republic of China. Conclusion։ The results obtained allow us to justify the return to treatment regimens using doxycycline, as one of the most adequate domestic tetracycline drugs.

Study of the activity of sunflower honey against a mixed microbial association isolated from bees with signs of dyspepsia in laboratory conditions

Beekeeping is one of the essential branches of agriculture in Ukraine, the main activity of which is aimed at breeding bees and obtaining honey and other products beneficial for human health. Maintaining the physiological state of bee colonies at the proper level is one of the essential tasks of veterinary medicine doctors and beekeepers. Compliance with veterinary and sanitary requirements at bee farms is the basis of preventing infectious pathologies in bee colonies. Since the body of insects has a fast metabolism, any infectious pathology quickly acquires a massive manifestation. One indicative symptom of infectious damage to the “gut” of bees is dyspepsia. Diarrhea, anorexia, and loss of productivity are observed in bees in this condition. The market of means to prevent such pathological manifestations in beekeeping is relatively narrow. The healing and favorable properties of honey, manifested in pain-relieving, antimicrobial and anti-inflammatory effects, have been known since ancient times. Sunflower honey differs from other types in a wide range of components, particularly phytoncides, which inhibit the growth of pathogenic microorganisms. Therefore, the main goal of the experiment was a laboratory study of the effect of different concentrations of sunflower honey sieve on the mixed microbial association isolated from bees with signs of dyspepsia. The activity of sunflower honey in laboratory conditions was studied by the disco-diffusion method in Petri dishes on MPA medium (meat-peptone agar). To obtain syrup from sunflower honey, sunflower honey was diluted with distilled water in a ratio of 1:1, working solutions were prepared from sunflower honey syrup in dilutions of 1:2, 1:4, 1:10, 1:100. The data analysis indicates the bacteriostatic activity of the syrup from sunflower honey in all studied concentrations concerning the mixed microbial association. Moreover, the largest diameter of the growth inhibition zone of the studied microorganisms was noted when the syrup from sunflower honey was diluted in a ratio of 1:10 (19.2 ± 0.42 mm). In turn, the antagonistic effect of the syrup from sunflower honey was observed in all dilutions concerning the mixed microbial association, where the largest diameter of the antagonism was 19.6 ± 0.27 mm when the disc was impregnated with the native working solution. Thus, it is promising to accumulate and identify a pure culture antagonist concerning a mixed culture of bacteria isolated during bee diarrhea to further create a pharmacological agent for preventing infectious pathologies of bees in unhealthy apiaries.

Synovial microflora of large joints in patients of a multidisciplinary hospital

Relevance. There is no doubt that microorganisms participate in occurrence and development of septic process in joints. However, the issue of etiological significance of each agent remains controversial, because, in spite of the general trends, indicating the participation of numerous microorganisms in the development of articular pathology, each result of microbiological analysis concerns only a specific case in the territorial and clinical aspects. The aim of the study - microbiological research of synovial fluid obtained from knee joint during synovitis after its aspiration in patients of various departments of the Stavropol Regional Clinical Hospital. Materials and Methods . There were studied 198 samples of synovial fluid. Primary inoculation of puncture was performed with subsequent isolation, identification of the cultures by mass spectrometry and assessment of their antibiotic sensitivity by discodiffusion method. Results and Discussion . 11 cultures of bacterial pathogens were isolated. Gram-positive cocci - 82 %, of which 77.8 % - microorganisms of Staphylococcus genus (44.4 % S.aureus , 33.4 % S.epidermidis ), 22.2 % - other gram-positive cocci: one strain of each, Enterococcus faecium and Streptococcus mitis . Gram-negative pathogens are represented by K.neumoniae and P.aeruginosa with a total content of 18 %. Highly virulent microorganisms S.aureus , K.neumoniae and P.aeruginosa are isolated from the synovial fluid of patients of the surgical departments (orthopedotraumatological No. 1, No. 2) and the rheumatological department. Microorganisms with low virulence E.faecium , S.mitis and S.epidermidis are isolated from synovial fluid of patients of various departments. No obvious resistance of isolated pathogens to antimicrobial drugs has been registered. Conclusion . The presence and species affiliation of the microorganisms identified in synovial fluid allows predicting their etiological significance in development of septic process in joints. Their role as causative agents of nosocomial infections typical for a medical institution is not excluded. The presence of articular pathology in each of the examined departments dictates the need for a clear understanding of the importance of timely and high-quality joint aspiration followed by microbiological examination in almost all patients with damage of large joints, including patients without clinical signs of septic arthritis. Such an approach that makes it possible to identify a greater number of causative agents of septic arthritis and quickly evaluate the dynamics of their antimicrobial resistance should become an obligatory part of a comprehensive research and treatment of a patient with arthritis in multi-fi eld hospitals.

ИССЛЕДОВАНИЕ ВОЗДЕЙСТВИЯ ИМПУЛЬСНОГО МАГНИТНОГО ПОЛЯ НА БИОЛОГИЧЕСКУЮ АКТИВНОСТЬ 1,1-БИС(1H-ИМИДАЗОЛ-1-ИЛ) МЕТАНИМИНА

The paper is devoted to the study of pulsed magnetic field impacting at the biological activity of a newly synthesized antifungal drug based on the imidazole 1,1-Bis(1H-imidazole-1-il)metanimine. Two experimental methods were consistently used for the study like as the treatment of an antifungal drug through installation of electromagnetic pulse emission and analysis of the results of treatment with the disco-diffusion method. During the experiments, the hypothesis of an increase in the antimycotic activity of an antifungal drug under the influence of a pulsed magnetic field was tested. The monitoring objects of the experiment were strains of the Penicillium adametzoides and the Aspergillus flavus. The antifungal drug was treated on the magnetic-pulse installation at the electromagnetic field strength H=(0.09÷0.27)∙106 A/m at frequency f=40 kHz with the number of pulses n=1. The analysis of experimental results has shown that the pulsed magnetic field has an effect on the antifungal drug, during which there is an inhibition of the growth of the colony of Aspergillus flavus by 71%. At the same time, in the process of studying the effect of the unirradiated antifungal drug impact at the grown colonies of the Aspergillus flavus, were not recorded the lysis zones increasing. Studying of the effect of the irradiated antifungal drug impact at the inhibition of the growth of the colony of the Penicillium adametzioides, there was not recorded lysis zones significant increasing. At the same time, during the experiment on the research of effect of the antifungal drug that was treated with a pulsed magnetic field at the grown colonies of the fungus Penicillium adametzioides, the maximum significant increase in lysis zones by 13% was discovered.

INVESTIGATING SENSITIVITY OF TYPICAL STRAINS AND CLINICAL ISOLATES OF STAPHYLOCOCCUS SPP. TO DECASAN, CHLORHEXIDINE AND IODOPHERE BY DISCA-DIFFUSION METHOD EUCAST

Antibiotic resistance is a global challenge, whose emergence is associated with the irrational and uncontrolled use of antimicrobial drugs, or the use of antibiotics to prevent local and systemic complications during the surgical operations. Therefore, the number of failed outcomes of the planned treatment of infectious and inflammatory processes with antibiotics has increased. Given this fact, it is important to study the potential of antiseptic drugs, which usually do not cause the microorganism resistance and thus are more advantageous over antibiotics. Objective of this study is to compare the effects of antiseptics Decasan, Chlorhexidine and Iodoform on clinical and typical strains of microorganisms using the disco-diffusion method according to the EUCAST. Materials and methods: Typical strains of Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 14990 were used as the studied cultures of microorganisms. Clinical isolates of the microorganisms Staphylococcus aureus, Staphylococcus epidermidis were collected from patients with postextraction complications, who took treatment at surgical departments of Poltava. Identification of isolated cultures was performed using an automatic bacteriological analyzer Vitec-2 compact bioMarieux (France). The antibacterial effect of antiseptic drugs Dekasan, Chlorhexidine, Iodoform was studied. Given that iodoform is poorly soluble in water, we used its 5% alcohol solution, which was prepared ex tempore. The susceptibility of the studied strains to antiseptics was determined by disco-diffusion method according to the EUCAST committee. The determination was performed by using Mueller-Hinton medium (HIMEDIA, India) with standard sterile disks, which were not impregnated (HIMEDIA, India). Then we impregnated them with solutions of Decasan, Chlorhexidine and 5% alcohol solution of iodoform. We used a microbial inoculum equivalent to according to the McFarland turbidity standard. Prepared Petri dishes containing impregnated paper disks were incubated overnight at 35-36 °C, after which the results were determined. Results and discussion: The study has shown that the antiseptic Decasan has a greater antistaphylococcal effect on typical strains and clinical isolates of staphylococci compared to other antiseptics, which are often used in dentistry. The lowest antistaphylococcal effect on the studied microorganisms has been found by applying 5% alcohol solution of iodoform, Chlorhexidine has demonstrated the moderate effect on the strains under the study.

The prospects of finding new treatments for acne

An important role in the development of acne is played by the activity of the skin microflora (namely the bacteria Propionibacterum acnes) and members of the genus Staphylococcus. In the schemes of complex treatment of patients with this disease, antibiotics from among macrolides or lincosamides are mainly used. It is of interest to study the current state of susceptibility of staphylococci and propionic bacteria to these drugs, as well as to other antimicrobial agents in order to determine the prospects for expanding the arsenal of methods for treating acne. The aim of the study was to study the susceptibility of microorganisms involved in the development of acne to antimicrobials and antagonistic effects of probiotic strains of lactobacilli. We conducted a bacteriological study of the content of rash elements in 60 patients with acne. The biological characteristics of 40 strains of Staphylococcus spp. and 15 strains of Propionibacterum acnes isolated and researched. The sensitivity of microorganisms to antibiotics and antiseptics was determined by the disco-diffusion method and the method of serial double dilutions of drugs in a liquid nutrient medium. Determination of the sensitivity of acne pathogens to the antagonistic effect of lactobacilli was performed by the method of two-layer agar by reducing the number of microorganisms. The results of the study made it possible to establish that the isolated strains of bacteria show a low level of sensitivity to antimicrobials, which in medical practice are most often used for topical therapy of acne. Only 17.5 % of isolated staphylococcal strains were sensitive to erythromycin, only 45.0 % of strains of this species were sensitive to clindamycin. Strains of Propionibacterum acnes showed a higher level of sensitivity to antibiotics than staphylococci. However, the established indicators do not allow to consider highly effective means for treatment of acne on their basis. At the same time, a high level of sensitivity of acne pathogens to antiseptic drugs decamethoxine and Aeroplysinin 1 and antagonistic effect of Lactobacillus acidophilus was established. Thus, the strains of Propionibacterum acnes and Staphylococcus spp., involved in the development of acne, are characterized by high levels of resistance to erythromycin, clindamycin, chloramphenicol, benzoyl peroxide, which are now the basis of the arsenal of topical therapy for patients with this disease. There is a need to find new effective drugs for the etiotropic therapy of acne.

Efficacy of Photodynamic Inactivation against the Major Human Antibiotic-Resistant Uropathogens

Photodynamic inactivation (PDI) is considered to be an effective method of prevention of postoperative complications of urolithiasis. The present study shows a complex approach to assess the efficacy of PDI of drug resistant bacteria associated with renal calculi. Bacterial strains associated with renal calculi were isolated and identified using standard methods of bacteriological analysis and tested for drug resistance to 10 antibiotics by the disco-diffusion method. Uropathogenic bacterial strains present in 78.7 ± 5.2% of the infected samples from the total number of analyzed calculi. The most frequent representatives belonged to the genera Staphylococcus, Escherichia, and Enterococcus. All tested strains showed high antibiotic resistance. Representatives of the most common bacterial genera in the calculi were used as models for the selection of PD exposure modes. It was found that the maximum time of photosensitizer accumulation depends on the structure of the bacterial cell wall: 30 min for Gram-negative strains and 60 min for Gram-positive ones. Optimal modes of PD exposure to antibiotic-resistant uropathogenic microorganisms were selected: 50 µg/mL Fotoditazin and 150 mW laser power. The maximal bactericidal activity of PDI against uropathogenic microorganisms was shown for Enterococcus faecalis, and Staphylococcus aureus. The bacteriostatic effect was found against Escherichia coli and Proteus mirabilis.

ANTIBIOTIC SENSITIVITY ISOLATION EVALUATION OF MAJOR MICROORGANISMS IN PERIODONTAL TISSUE PATHOLOGY

Relevance of research The loss of effectiveness and activity of antibiotics is caused by their irrational and inappropriate use (especially in self-medication). The risk of antibiotic-resistant mikrobiom potentially be associated not only with time proceeding systemic antibacterial component in the protocol complex treatment of periodontitis but with specific combinations of different used drugs duration, efficiency previously performed mechanical treatment by open or closed curettage, especially the dosing of selected antibiotics middlemen. In – depth study and development of or personalized approaches to treatment is relevant periodontitis by individualizing the choice of appropriate antibiotics for incorporation into the algorithm of complex therapy, or universal approaches, the possibility of implementation of which depends on arguing the effectiveness of a particular combination of antibacterial agents for the vast majority of patients according to studies with sufficient samples. Study Goal is to assess the levels of antibiotic resistance and antibiotic sensitivity of isolates of major microorganisms in periodontal tissue pathology. Materials and methods of research. The research was conducted on the basis of the University Dental Clinic and private dental clinics in Uzhhorod. Determination of levels antibiotic sensitivity was carried out using a disco-diffusion method with the advice and algorithm identified by order MOH Ukraine 05.04.2007 № 167 "On Approval of guidelines" Determination of the sensitivity of microorganisms to antibiotics and in accordance with the recommendations EUCAST (Eurepean Committee on Antimicrobial Susceptibility Testing). During the testing, standard sets of discs with antibiotics and appropriate test cultures were used, which were seeded with microorganisms obtained from patients with generalized periodontitis of varying severity. Research results and their discussion. During the microbiological analysis of smears obtained from periodontal pockets of whole patients study group, microorganisms were identified, which were characterized by relatively high levels of prevalence, among them: P. gingivalis, T. forsythia, F. nucleatum, P. intermedia, A. actinomycetemcomitans, K. pneumoniae, E. coli, E. cloaceae, S. aureus, S. haemolyticus, S. viridans, S. pyogenes. A detailed analysis of the distribution of mean levels of prevalence of antibiotic sensitivity and antibiotic resistance among the analyzed isolates was performed. The results of antibioticograms differ depending on the qualitative and quantitative composition of the isolated microorganisms, their levels of antibiotic sensitivity and antibiotic resistance. This distribution of results indicates the feasibility of a patient-centered approach to treatment, based on the preliminary identification of microorganisms isolated from periodontal pockets of patients, as well as determining the levels of their antibiotic sensitivity and antibiotic resistance. Conclusion. The application of the approach with preliminary determination of antibiotic sensitivity to microorganisms cultured from the oral cavity is characterized by the relevant biological principles of conducting. Prospects for further research. The analysis of the effectiveness of adjuvant antibiotic therapy in the process of complex treatment of periodontal patients and the development of personalized approaches to the treatment of periodontitis are promising.