The activity of ceftazidime-avibactam against gram-negative bacteria – pathogens of wound burn infection

Abstract

Introduction.The most common mechanism for the resistance of gram-negative bacteria to various classes of antimicrobial agents, including carbapenems, is the production of beta-lactamases, enzymes that destroy the beta-lactam ring.Purpose of the study.To analyze the activity of ceftazidime/avibactam against pseudomonads and Klebsiella isolated in patients with severe thermal injury.Materials and methods.We analyzed 2553 isolates – pathogens of wound burn infection in patients with thermal injury treated in 2018–2019. Results and discussion. Phenotypically, 72,8% of the analyzed P. aeruginosa were resistant to carbapenems, while 56,3% of carbapenemresistant strains produce group Vim metal-beta-lactamases. Analysis of the effectiveness of ceftazidime/avibactam against P. aeruginosa showed its high efficiency, more than half of the strains (55,3%) were sensitive to the drug. The studied K. pneumoniae phenotypically in 63,1% were carbapenem-resistant. Among K. pneumoniae resistant to carbapenems, 89,3% of the strains revealed genes of serine KPC or OXA-48 like carbapenemases. In vitro ceftazidime/avibactam was active against two-thirds (72,7%) of K. pneumoniae strains.Сonclusions.1. Gram-negative microorganisms occupy 30,2% of the etiological structure of a wound burn infection. 2. Phenotypically 72,8% of Pseudomonas aeruginosa are resistant to carbapenems, 56,3% of them produce metal beta-lactamases. 3. 63,1% of Klebsiella pneumoniae isolated in patients with thermal injury are resistant to carbapenems, 89,3% of them carry cattle or OXA-48 genes like carbapenemases. 4. Ceftazidime / avibactam in vitro showed activity against P. aeruginosa and K. pneumoniae, with 55,3% and 72,7% of the strains, respectively, being sensitive.