Molecular characterization of Mycoplasma pneumoniae infections in Moscow from 2015 to 2018

The aim of this study was to assess which Mycoplasma pneumoniae genotypes were present in Moscow during the years 2015-2018 and whether the proportion between detected genotypes changed over time. We were also interested in the presence of macrolide resistance (MR)Mycoplasma pneumoniae. We performed multilocus variable-number tandem-repeat (VNTR) analysis (MLVA), SNP typing, and mutation typing in the 23S rRNA gene from 117 M. pneumoniae clinical isolates. Our analysis suggests two major MLVA types: 4572 and 3562. In 2017-2018, MLVA type 4572 gradually became predominant. In general, the SNP type range is the same as described earlier for European countries. The analysis of MR mutations showed that 7% of the isolates had an A2063G mutation in the 23S rRNA gene with no isolates carrying an A2064G mutation. In 2017-2018, MLVA type 4572 (SNP type 1) begins to spread in Moscow, which was widespread globally, especially in Asian countries. SNP typing of our sample showed higher discriminatory power than MLVA typing.

[Antimicrobial susceptibility and molecular mechanisms of resistance to beta-lactams of gram-negative microorganisms--causative agents of nosocomial infections]

Profiles and mechanisms of resistance to beta-lactam antibiotics of isolates of Gram-negative microorganisms, which are causative agents of infections in Intensive Care Unit of hospital surgery department, were studied. Two hundred and ten clinical isolates were studied: Pseudomonas aeruginosa--86 strains (40.9%), Acinetobacter baummanii--45 strains (21.4%), Klebsiella pneumoniae--52 strains (24.8%), Escherichia coli--23 strains (11%), Enterobacter spp.--4 strains (1.9%). Profiles of antibiotic resistance were studied by the method of serial microdilutions; detection of most widespread and clinically significant genes of beta-lactamases of Gram-negative bacteria was performed by polymerase chain reaction. Carbapenems and cefoperazone/sulbactam were the most active antibiotics. Local features of distribution of beta-lactamase coding genes (TEM, SHV, CTX) in K. pneumoniae and E. coli isolates were revealed. Eleven strains of P. aeruginosa resistant to carbapenems and possessing genetic determinants of VIM-group, which codes metallo-beta-lactamases, were isolated. Obtained data allows to assess the parameters of resistance to beta-lactam antibiotics and to reveal the main mechanisms of such resistance in etiologic agents of nosocomial infections, that, in its turn, allows to choose preparations for etiotropic therapy.

[Resistance epidemiology of gramnegative nonfermenting pathogens of nosocomial infections in intensive care units and surgical departments]

Etiological structure, patterns and antibiotic resistance mechanisms of gramnegative nonfermenting pathogens of nosocomial infections isolated from patients in intensive care units and surgical departments were investigated. One hundred thirty one clinical isolates, including 86 (65.6%) isolates of Pseudomonas aeruginosa and 45 (34.4%) isolates of Acinetobacter baumannii were tested. Carbapenems and cefoperazone/sulbactam showed the highest activity against the tested isolates. Eleven carbapenem resistant strains of P. aeruginosa were detected. The strains were found to possess genetic determinants of the VIM group encoding metal beta-lactamases.

[Nosocomial infections: epidemiology, pathogenesis, etiology, antibacterial therapy, and prophylaxis]

The review deals with one of the most actual problems of modern medicine, i.e. nosocomial infections. Criteria, epidemiology, pathogenesis and etiology of nosocomial infections are discussed. Up-to-date approaches to prophylaxis and control of nosocomial infections are indicated with special attention to the advantages and disadvantages of some widely used methods. Data on structure of nosocomial infections and their specific features in multipurpose hospitals are indicated. General principles of antimicrobial chemotherapy of nosocomial infections are formulated. The importance on multicentre studies of resistance of hospital pathogens in accordance with internationally recognised methodology is emphasised.