The research of the susceptibility to antimicrobial medicines of Acinetobacter baumannii as pathogens of infectious complications in patients with hard burns

Abstract

Antibiotic-resistant strains of Acinetobacter baumannii has become yet recognized one of the most leading causative pathogens of infectious complications in patients with severe burns. This greatly complicates the treatment of such patients and requires in-depth study with a prognostic determination of the dynamics of antimicrobial efficacy of antibacterial agents. The aim — to study the susceptibility to antibiotics in clinical isolates of A. baumannii, pathogens of infectious complications in patients with hard burns. From patients (n=435) with burns of the 2ndb – 3rd degree, isolates of A.baumannii were received in early period after burn trauma before antibiotic therapy. Patients who participated in the study received standard surgical, complex general and local treatment in the required volume according to the protocols for the treatment of this disease. In total, 222 clinical strains of A.baumannii were isolated and identified during 2011–2016. The susceptibility of clinical strains A.baumannii to the following beta-lactam antibiotics: ampicillin-sulbactam, amoxicillin-clavulanate, piperacillin-tazobactam, cefoperazone-sulbactam, imipenem, meropenem, was determined by standard microbiological methods (qualitative disco-diffusion and quantitative double dilution methods). Using statistical methods, mathematical and analytical prognosis of the real sensitivity of A. baumannii strains to these antibiotics with the use of licensed computer programs “STATISTICA 7” was carried out; “Matlab 7.11”. The results of the study demonstrated a low susceptibility of clinical strains of A.baumannii to the studied beta-lactam antibiotics. The change in the antibiotic susceptibility profile of A.baumannii in 2011–2016 was established. Thus, the vast majority of strains were of low susceptibility to cefoperazone-sulbactam (55,6%), imipenem (57,1%) and meropenem (52,8%). In the dynamics, the prognostic decrease of the sensitivity in clinical isolates of Acinetobacteria to the antibiotics has been proved. The susceptibility of A.baumannii to amoxicillin-clavulanate was consistently low (less than 13,3%), and significantly decreased to cefoperazone–sulbactam (25,0%). The resistance of this pathogen to imipenem (up to 75,0%), meropenem (up to 84,3%) has been established to increase. At the same time, the gradual restoration of the susceptibility of A.baumannii to ampicillin–sulbactam (from 3,4% to 70,2%) was determined. The A.baumannii, pathogens of infectious complications in patients with burns, were characterized by a decrease in sensitivity to inhibitor-protected penicillins, carbapenems except ampicillin–sulbactam, that proved their low effectiveness against this pathogen.