ABSTRACT
In 2003-2023, amid 5,436 Acinetobacter baumannii isolates collected globally through the Multidrug-Resistant Organism Repository and Surveillance Network, 97 were ST19PAS, 34 of which carbapenem-resistant. Strains (n = 32) sampled after 2019 harboured either bla OXA-23, bla OXA-72, and/or bla NDM-5. Phylogenetic analysis of the 97 isolates and 11 publicly available ST19 genomes revealed three sub-lineages of carbapenemase-producing isolates from mainly Ukraine and Georgia, including an epidemic clone carrying all three carbapenemase genes. Infection control and global surveillance of carbapenem-resistant A. baumannii remain important.
Subject(s)
Acinetobacter Infections , Acinetobacter baumannii , Bacterial Proteins , Microbial Sensitivity Tests , beta-Lactamases , beta-Lactamases/genetics , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/enzymology , Humans , Acinetobacter Infections/microbiology , Acinetobacter Infections/epidemiology , Bacterial Proteins/genetics , Ukraine/epidemiology , Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , Phylogeny , Drug Resistance, Multiple, Bacterial/genetics , Georgia (Republic)/epidemiology , Multilocus Sequence TypingABSTRACT
OBJECTIVE: The aim: To study the influence of chemical, physical factors on the biofilm forming activity of P. aeruginosa, A. baumannii. PATIENTS AND METHODS: Materials and methods: Biofilm forming activity of P. aeruginosa (10 isolates) and A. baumannii (10 isolates) was studied in nutrient media of different composition. There was used the method in 96-well crystalline violet staining plates with spectrophotometry (STAT FAX®4300, wavelength of 620 nm). RESULTS: Results: Results showed that in standard medium (trypto-soy broth), strains of P. aeruginosa (90%) and A. baumannii (60%) obtained high biofilm forming activity. A. baumannii formed biofilms even in sterile water. Biofilm forming activity of urease positive P. aeruginosa increased in the medium with 1.0% urea. Both Acinetbacteria and Pseudomonas intensively produced their biofilms in the presence of 5% serum or sub-bacteriostatic concentrations of levofloxacin in the media. High concentrations of sodium chloride inhibited their biofilm activity. CONCLUSION: Conclusions: Isolates of Acinetobacter and Pseudomonas obtain the protective biofilm-forming ability under such adverse environmental conditions as insufficient nutrients, high osmotic pressure, the presence of antibiotics but at high concentrations sodium chloride biofilm-formation is stimulated only in the first bacteria and suppressed in the second one.
