Purpose: Urinary tract infections are the second most common children’s infections. The prevalence in Russian Federation is 18 cases in 1000. Also, spreading of antimicrobials resistance among children's UTI poses a high epidemiological threat.

Materials and methods: Retrospective analysis was performed with 163 sequentially collected midstream portion of urine. Samples were collected from patients of 4 weeks to 17 years in FSAI of the Ministry of Health of the Russian Federation «NMR Center for Children's Health» during 2019. Bacteriological tests were performed on URISELECT™ (Bio-Rad Laboratories, USA) medium. Species were determined by MALDI-TOF MS (Bruker Daltonics, Germany) and bacteriological analyzer Vitek 2 (BioMerieux, France). Antimicrobial susceptibility tests were performed using disc-diffusion method (Bio-Rad, USA) and E-tests (BioMerieux, France). DNA extraction was performed using «RIBO-prep» (AmpliSens, Russia). Detection of antimicrobial resistance gene determinants was performed using quantitative real-time PCR assays: «AmpliSens® MDR MBL-FL», «AmpliSens® MDR KPC-OXA-48-FL», «AmpliSens® ESBL CTX-M», «AmpliSens® MDR A.b.-OXA-FL», and «AmpliSens® MDR VRE-FL» (all Central Research Institute of Epidemiology, Russia).

Results and Discussion: Species of uropathogens were identified in 69 samples while others being classified as «gut flora» (n=14), «coccus flora» (n=10) or «mixed flora» (n=70). The most prevalent uropathogens were Escherichia coli (24.7%) and Enterococcus faecalice (20.3%). Genes of CTX-M-like group, including blaCTX-M-1-like, blaCTX-M-2-like, blaCTX-M-8-like, and blaCTX-M-9-like, were determined in 33%, blaVIM in 6%, blaIMP in 1%, blaNMD in 4%, and blaOXA-48-like in 3% of studied samples. No blaKPC genes were identified. In all 69 samples with identified species, antimicrobial resistance profile, determined by microbiological methods, was in accordance with found gene determinants, including resistance to penicillins, cephalosporins, carbapenems, and monobactams.

Conclusions: It is of great importance to introduce antimicrobial resistance genes determinants testing in clinical practice. It would provide the opportunity to determine correct in-time treatment for antimicrobials resistant bacteria infections.