EP196 INTEGRATING WHOLE-GENOME SEQUENCING DATA AND MICROBIOLOGICAL PROFILE OF MULTIDRUG-RESISTANT ACINETOBACTER BAUMANNII INFECTIONS IN SKIN ULCERS.

Aim: Acinetobacter baumannii is a leading nosocomial pathogen worldwide and a significant threat in skin ulcer. The therapeutic options are limited due to high rates of antibiotic resistance and virulence factors. This study investigates the clinical impact of A. baumannii isolates in patients with chronic leg ulcers. Method: Antibiotic resistance, a comprehensive bioinformatic analysis, and the biofilm-forming ability of 18 A. baumannii isolates were examined. Results: Most of the isolates were resistant to fluoroquinolones (66.7%), aminoglycosides (55.5%), and carbapenems (44.4%). In addition, many genes encoding for virulence factors, (adeF, bfmS, bfmR, and bau) and iron uptake, were highly prevalent in A. baumannii isolates. Moreover, genes responsible for fimbriae production (csu), early adhesion (ompA), and biofilm formation (pgaB, pgaC, pgaD, ageG, adeH, and bap) were reported in more than 89% of the strains. Sequence type (ST) 2 was the most prevalent (44.4%). It was associated with high rates of antimicrobial resistance, low biomass production, and poor adhesion than other STs and A. baumannii ATCC 19606. The median MIC90 values for these isolates were 0.5 μg/mL (0.25-32 μg/mL) for colistin and 1.0 μg/ mL (0.125--4 μg/mL) for cefiderocol. In contrast, the minimal biofilm eradication concentration (MBEC90) for cefiderocol and colistin was 2 μg/mL (0.25-64 μg/mL) and 2 μg/mL (0.25-128), respectively. Conclusion: This study provides significant information about the genetic determinants and virulence factors of A. baumannii isolates to optimize antibiotic prescribing and stewardship programs and to improve the treatment of these infections among patients with chronic leg ulcers. [ABSTRACT FROM AUTHOR]