Microbiological characteristics of pathogenic flora in children with acute and chronic pyelonephritis

The study of dynamically changing antibiotic sensitivity of uropathogenic strains in children with pyelonephritis is of great scientific and practical interest, since the course and outcome of the disease and the success of cure depend on it. Objective of the study: to study the microbial landscape of urine and antimicrobial sensitivity of pathogens in children with acute (AP) and exacerbation of chronic pyelonephritis (CP) for timely correction of empirical antibacterial (AB) therapy. Materials and methods of research: a prospective open non-randomized controlled singlecenter study to study the microbial landscape of urine and antimicrobial sensitivity of pathogens in children with AP and CP was conducted at the Speransky Children's City Clinical Hospital No. 9. Inclusion criteria: compliance with the diagnostic criteria for the onset of AP and CP, age from 1 to 14 years, the possibility of assessing the microbiological spectrum of urine before starting AB therapy, determination in urine cultures of strains producing extended spectrum betalactamases (ESBL) and/or carbapenemases (CP-CRE). Results: 552 results of urine bacteriological tests were analyzed. Bacteriuria was detected in 68,3% (n=376) patients, of which 161 (42,8%) were diagnosed with AP, 215 (57,2%) with CP. The structure of pathogens was dominated by gram-negative flora (53,8–70,8%), among which enterobacteria prevailed (79,5%), the dominant microorganism was E. coli (48%). Gram-positive microflora was represented by Enterococcus faecalis (35%). Among enterobacteriaceae, there was a statistically significant increase (p<0,05) in the number of ESBL and/or CP producers, as well as their associations, from 8,8% in 2016 to 25% in 2019–2020 with a peak increase of up to 31% in 2018. A study of resistograms noted that E. coli retains high levels of sensitivity to amoxicillin/clavulanate, however, since 2019, a high frequency of ceftriaxone-resistant strains has been recorded, and in 2020, the detection rate of resistant strains has increased to cefotaxime of E. coli strains. The highest and most stable activity against E. coli ESBL was shown by meropenem and ertapenem. There is a tendency towards a decrease in the sensitivity of Kl. pneumoniae to amoxicillin/clavuanate, fosfomycin and amikacin. The emergence in 2020 of strains of Enterococcus faecalis resistant to amoxicillin/clavuanate and a tendency to a decrease in sensitivity to gentamicin while maintaining a high sensitivity to amikacin were recorded. Conclusion: the results obtained indicate the importance of monitoring the AB-sensitivity of uropathogenic strains in order to increase the effectiveness of empiric therapy and reduce the prescription of inactive antibacterial drugs in children with AP and CP.