Staphylococcus aureus | CMAC

Staphylococcus aureus

Genetic characteristics of Staphylococcus aureus strains isolated from an intensive care unit of an infectious diseases hospital during the COVID-19 pandemic

Objective. To provide a genetic characterization based on whole-genome sequencing (WGS) data of S. aureus isolates identified in one intensive care unit (ICU) during the COVID-19 pandemic. Materials and Methods. WGS on Illumina MiSeq was performed, generating twenty S. aureus sequences isolated from patients and environmental surfaces. Bioinformatic analysis included typing, identification of antimicrobial resistance (AMR) determinants, virulence factors, plasmid replicons, and phylogenetic analysis. Results. Significant genetic diversity was revealed, comprising four clonal complexes (CCs): CC15 – 6⁄20 (30%), CC8 – 3⁄20 (15%), CC22 – 2⁄20 (10%), and CC97 – 2⁄20 (10%); while 7⁄20 (35%) of isolates had an indeterminate CC.

Genetic determinants of antibiotic resistance in Staphylococcus aureus isolated from patients with chronic lung infection in cystic fibrosis

Objective. To investigate antibiotic resistance of S. aureus isolates from cystic fibrosis (CF) patients with chronic lung infection and to identify its genetic determinants. Materials and Methods. The antibiotic susceptibility of 629 S. aureus isolates from pediatric and adult CF patients was analyzed using the disk diffusion method and E-test in accordance with EUCAST guidelines. All strains were screened by PCR for the presence of the mecA and mecC genes.

Microbiological activity of bovhyaluronidaze azoximer against microbial biofilms

Objective. To evaluate the ability of bovhyaluronidaze azoximer to destroy biofilms formed by clinical strains of microorganisms. Materials and Methods. The study included 50 clinical strains of Staphylococcus aureus (n = 25), Staphylococcus epidermidis (n = 6), Enterococcus faecalis (n = 8), Escherichia coli (n = 9), Candida albicans (n = 2). Antimicrobial susceptibility testing was performed using broth microdilution method. Biofilm formation culturing in presence of antibiotics, or bovhyaluronidaze azoximer, or their combinations was assessed in Mueller-Hinton broth and brain heart broth in 96-well plates.

Ceftaroline fosamil – fifth-generation cephalosporin with anti-MRSA activity in the treatment of severe infections in pediatric practice

Сeftaroline fosamil is a fifth-generation cephalosporin and a unique β-lactam and the only currently registered in the Russian Federation cephalosporin with activity against MRSA. Сeftaroline is approved for use in pediatric practice for the …

Microbiological activity of thiamphenicol and thiamphenicol glycinate acetylcysteinate against clinically significant microorganisms and their biofilms

Objective. To determine the minimum inhibitory concentrations of thiamphenicol and thiamphenicol glycinate acetylcysteinate against clinically significant microorganisms and determine their efficacy against microbial biofilms. Materials and Methods. This study included 48 clinical strains isolated from the sputum of patients with respiratory tract infections (16 S. pneumoniae, K. pneumoniae and S. aureus strains). Antimicrobial susceptibility testing was performed using broth microdilution method. Biofilm formation culturing with antibiotics, N-acetylcysteine and their combinations was assessed in Mueller-Hinton broth and brain heart broth in 96-well plates.

Effects of bacteriophages on biofilms formed by Staphylococcus aureus isolated from patients with orthopedic infection

Objective. To study effects of bacteriophages on biofilm formation and formed biofilm by S. aureus isolated from patients with orthopedic infection. Materials and Methods. A total of 50 clinical strains of S. aureus were tested. Species identification was performed by MALDI-TOF MS, antibiotic susceptibility – in accordance with the EUCAST v21. Isolates susceptibility to bacteriophages «Sextafag» (Microgen, Russia) was determined by MPA medium. The antibacterial activity of phages against S.

The current view on betalactam resistance in Staphylococcus aureus

The review presents the current view on the different resistance mechanisms of Staphylococcus aureus to beta-lactams, which are ones of the main antibiotics of choice for the treatment of staphylococcal infections. Currently, there are several …

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.

Unresolved issues of antibiotic therapy of infections caused by Staphylococcus aureus

Staphylococcal infections are widespread among outpatients and hospitalized patients. Despite the apparent diversity of the “menu” of anti-staphylococcal drugs, treatment results in several patients are not good as expected. This is due to the …

Antimicrobial resistance of nosocomial Staphylococcus aureus isolates in Russia: results of multicenter epidemiological study «MARATHON» 2013-2014

The study included 418 of the 841 clinical isolates of S. aureus, which were regarded as nosocomial. These 418 clinical nosocomial S. aureus strains were isolated in 2013-2014 from patients hospitalized in 25 hospitals in 19 Russian cities. …