Personal Experience

Cefazolin inoculum effect among methicillinsusceptible Staphylococcus aureus isolated from patients with skin infections

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.

Local microbiological monitoring as a basis for determining etiological significance of conditional pathogens: data from a burn intensive care unit

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.

In vitro activity of thiamphenicol against Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes clinical isolates

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.

Methodological approaches to fluoroquinolone susceptibility testing of Salmonella

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.

Effect of 23S rRNA gene mutations in Mycoplasma pneumoniae on severity of communityacquired pneumonia in young adult patients treated at the Smolensk militar y hospital

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.

Impact of healthcare workers’ cell phones on the spread of multidrugresistant microorganisms

Objective. To study the possibility of transferring multidrug resistant microorganisms through healthcare workers’ cell phones between medical institutions in Khabarovsk. Materials and Methods. It was a comparative prospective study to assess contamination of cell phones with multidrug-resistant microorganisms in a population (n = 30) and among intensive care unit (ICU) physicians (n = 60) in medical institutions. Antimicrobial susceptibility testing was performed by disc-diffusion method. A total of 514 healthcare workers from medical institutions of Khabarovsk were interviewed.

Etiology of community-acquired pneumonia and prevalence of comorbidities in elderly patient population

Objective. To investigate the mortality rate, comorbidity prevalence, and etiology of community-acquired pneumonia (CAP) in elderly patient population. Materials and Methods. Hospitalized elderly patients with CAP were distributed into the following age groups: 65–74 years (group I), 75–84 years (group II) and 85–94 years (group III). The patients’ medical records were used for determining comorbidities and mortality rate. In order to determine etiology of CAP, sputum or BAL samples were collected.

Clinical and microbiological characteristics of periprosthetic hip and knee infections

Objective. To characterize periprosthetic joint infection in patients undergoing a total hip and knee joint replacement. Materials and Methods. A total of 77 patients with periprosthetic infection following hip and knee joint replacement hospitalized in Grodno City Clinical Hospital were studied over the period of 2014-2018. Wound discharge, tissue samples, and fistula’s wall swab were used for microbiological tests. The analysis of surgical treatment of patients with deep periprosthetic knee and hip joint infection has been performed.

Appraisal of the domestic kit «MICMICRO » for antimicrobial susceptibility testing by serial microdilution method

Objective. To assess efficiency of the “MIC-MICRO” kit developed in the Department of New Technologies of the Saint-Petersburg Pasteur Institute, on reference strains and clinical bacterial isolates. Materials and Methods. In order to assess the “MIC-MICRO” kit, several options of its execution were used, including different groups of antibiotics: aztreonam, amikacin, gentamicin, colistin, meropenem, nitrofurantoin, chloramphenicol, cefotaxime, ceftriaxone, ciprofloxacin, erythromycin. In order to determine the range of antibiotic values, the EUCAST-2020 database was used.

Experience with the use of microbiological analyzer BactoSCREEN in a routine practice of clinical microbiology laboratory

Objective. Assessment of bacterial identification effectiveness in clinical microbiology laboratory using the MALDI-MS based system BactoSCREEN. Materials and Methods. Bacteriological testing was done by the cultivation on Сolumbia agar with 5% of sheep blood (at 37°C for 24 hours). Colonies for identification were selected based on their growth pattern, type of hemolysis, morphology and consistency. The species identification was done by the MALDI-MS using the microbiology analyzer BactoSCREEN. Apart from MALDI-MS, we used morphology and biochemical methods for species identification when necessary.