Personal Experience

Objective. To develop a technology for freezing and long-term storage of mycobacteria cultures and implement into a microbiological laboratory routine practice. Materials and Methods. For comparison between different condition, the media for freezing mycobacteria containing 0.9% NaCl or Middlebrook’s 7H9 medium with the addition of glycerol at various concentrations: 0%, 4.0%, 20.0%, 50.0% (by final volume) was evaluated. To freeze suspensions of cultures, two methods were used: one – using a cryo-freezer (cooling rate of 1°C/min), the second – direct placement in a deep freeze at a temperature of -80°C.

Objective. To determine functional anti-LPS specific serum bactericidal antibody (SBA) and opsonophagocytic killing antibody (OPKA) activities in mice immunized with a pentavalent candidate vaccine against Shigella flexneri 1b, 2a, 3a, 6, Y (PF). Materials and Methods. (CBA x C57 B1/6) F1 mice were immunized with a PF. 14 days after the reimmunization, serum samples were collected and the level of specific IgG in them was determined by ELISA. The sera of mice immunized with individual modified lipopolysaccharides (mLPS), which are part of PF, were used for positive control.

Objective. To study pathogenic factors (adhesion and biofilm formation) in F. solani isolated from skin of patients Materials and methods. A total of 86 strains of F. solani isolated from the skin of patients with a diagnosis of L30.3 “Infectious dermatitis” were selected. The reference strain F. solani F-819 was used for quality control. Samples were collected using a sterile cotton swab from an area of 5 × 5 cm.

Objective. To review and summarize literature data in studies of safety of the drug products used for the pathogenetic treatment of COVID-19. Materials and Methods. As the first stage of monitoring the drug’s safety, which are used in the treatment of COVID-19 in Russia, a systematic review of studies of the drug’s safety profiles was carried out: mefloquine, hydroxychloroquine, azithromycin, lopinavir/ritonavir, favipiravir, tocilizumab, olokizumab, baricitinib in the international databases Medline, PubMed, ClinicalTrials.

Objective. To improve stool sample culture and isolation of anaerobic flora, including Clostridioides difficile in the routine microbiological laboratory practice at the children’s oncology hospital. Materials and Methods. A total of 517 stool samples collected from patients in children’s oncology hospital from 2013 to 2015 were studied. All samples were analyzed by ELISA for C. difficile toxins and by culture according to dedicated 5 schemes for isolation of anaerobic bacteria, including C.

Objective. To evaluate frequency and intensity of cefazolin inoculum effect among methicillin-susceptible staphylococci isolated from patients with skin infections. Materials and Methods. A total of 80 methicillin susceptible isolates of Staphylococcus aureus were identified by cefoxitin disk-diffusion test and negative results of real-time PCR for mecA gene. Inoculum effect was measured by broth microdilution test with two inocula with concentrations of 5 × 105 CFU/mL and 5 × 107 CFU/mL.

Objective. To assess the etiology of infections, microbial associations and antimicrobial resistance in a burn intensive care unit. Materials and Methods. A microbiological study of 1322 biological samples from 195 patients with extensive burns included 479 blood samples, 82 respiratory samples, 326 urine samples, and 435 wound samples. Antimicrobial susceptibility testing was performed, and coefficients of constancy and associativity (CA), as well as the Jaccard coefficient were calculated. Results. The etiology of infections was represented by: Pseudomonas aeruginosa – 23%, Acinetobacter baumannii – 19.

Objective. To determine in vitro activity of thiamphenicol and other clinically available antimicrobials against clinical isolates of Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes. Materials and Methods. We included in the study 875 clinical isolates from 20 Russian cities during 2018–2019. Among tested strains, 126 were H. influenzae, 389 – S. pneumoniae, 360 – S. pyogenes. Antimicrobial susceptibility testing was performed using broth microdilution method according to ISO 20776-1:2006. AST results were interpreted according to EUCAST v.

Objective. To evaluate effectiveness of the various approaches to fluoroquinolone susceptibility testing of Salmonella, including S. typhi, taking into account molecular resistance mechanisms. Materials and Methods. The MIC values of ciprofloxacin were compared with the inhibition zone for pefloxacin disc, 5 mg (310 isolates) and nalidixic acid, 30 mg (420 isolates). MIC of ciprofloxacin was determined by gradient diffusion test and broth microdilution method. Muller – Hinton agar and Muller – Hinton broth, antibiotic discs and MICE-tests (Oxoid, UK) were used.

Objective. To evaluate effect of 23S rRNA gene mutations in Mycoplasma pneumoniae on severity of community-acquired pneumonia (CAP) in young adult patients. Materials and Methods. A total of 42 case histories of young adult patients with CAP treated at the Smolensk military hospital over the period of 25 October 2017 to 25 December 2019 were reviewed. «AmpliSens® Mycoplasma pneumoniae/Chlamydophila pneumoniae-FL» real-time PCR kit was used to detect M. pneumoniae from nasopharyngeal swabs collected prior to antimicrobial therapy.