Molecular-Genetic Mechanisms of Resistance to Antibiotic of the Pathogens in Patients with Thermal Burns and Infection

Infectious complications caused by antibiotic-resistant strains in burn-injury patients account for 30–75% of all deaths. For optimal clinical control, it is important to know the susceptibility profile, the mechanisms of antimicrobial resistance, and the predominant genetic lineage. The aim of the study is to investigate the mechanisms of antibiotic resistance of the main causative agents of pyroinflammatory complications in patients with burns. In 2011–2017, 90 patients were examined with deep burns who were being treated at the Regional Clinical Hospital. Materials were investigated by a bacteriological method (MALDI-TOF). Antibiotic sensitivity was studied by disk-diffusion, PCR, E-test, and serial dilutions in Muller–Hinton broth methods. Genotyping and determination of resistance mechanisms were studied by PCR sequencing. The prevalence of a mixed flora of multi- and extremely resistant pathogens, representatives of the ESKAPE group, has been established. A total of 66.7% of P. aeruginosa strains ( n = 9) had blaVIM, and 22.2% had blaCTX-M. Fifty percent of A. baumannii strains ( n = 8) had blaOXA-24-like, 25% had blaOXA-23-like, and 100% had blaOXA-51-like ompA and adeR. Fifty percent of K. pneumonia strains ( n = 2) had blaTEM and blaCTX-M, and 100% had blaSHV, ompK36. MRSA PVL-isolates ( n = 10) belonging to the ST239, spa t037, SCCmecIIIA, tst variant had the aacA-aphD and aadD resistance genes; ermA; tetM; cat (2.5-kb plasmid); mutations were revealed in GyrA-Ser84Leu and GrlA- Ser80Phe, as well as in rpoB-His481Asn and Ile527Met. The distribution of P. aeruginosa , A. baumannii , and K. pneumoniae strains with carbapenemases and other mechanisms among patients with burns was revealed. MRSA strains were due to the resistance genes and the presence of mutations in chromosomal genes.