Decoding the genome of Acinetobacter baumannii from a urinary tract infection case: A comprehensive analysis of...

Acinetobacter baumannii is an opportunistic multidrug-resistant (MDR) pathogen frequently associated with healthcare-associated infections, including urinary tract infections in critically ill patients. In this study, a carbapenem-resistant A. baumannii (CRAB) isolate, SGK_8A, obtained from an ICU patient, was subjected to whole-genome sequencing (WGS) to explore its genomic features. Species identification and antimicrobial susceptibility testing using the VITEK^® 2 system confirmed resistance to multiple antibiotics, while susceptibility to tigecycline and colistin was retained. WGS was performed using the Illumina NovaSeq 6000 platform, followed by de novo assembly and functional annotation using Unicycler, RAST, PATRIC, CARD, VFDB, and antiSMASH. The draft genome consisted of 3,939,487 bp with a GC content of 38.95% and an N50 value of 77,016 bp. Genome annotation identified 281 functional subsystems associated with cellular metabolism, stress response, and defense mechanisms. Phylogenetic analysis indicated close relatedness to reference strains ATCC 17,978, SDF, and AB30. Resistance gene analysis detected several β-lactamase genes, including bla_OXA- 23, bla_OXA- 51, and bla_OXA- 144, along with multiple additional antimicrobial resistance determinants. The genome also contained genes associated with adhesion, biofilm formation, and other virulence-related functions. Prophage analysis identified five phage regions, including a high-coverage contig that may represent a mobile genetic element (MGEs). Additionally, biosynthetic gene clusters and simple sequence repeats were identified within the genome. Overall, these findings provide a genomic overview of antimicrobial resistance determinants, virulence-associated genes, and MGEs present in the CRAB isolate SGK_8A. The results contribute to the growing genomic data on A. baumannii and may support future comparative and functional studies.