Comprehensive Genomic Analysis of PSU9449 Isolated from a Clinical Case in Thailand.

is one of the most significant multidrug-resistant bacteria. It poses considerable challenges in terms of treatment and causes hospital-acquired infections that lead to high morbidity and mortality. Colonization by in a patient without clinical signs of infection is a concern in hospital settings, as it is an opportunistic pathogen and can potentially be a multidrug-resistant strain. The objective of this study was to characterize and provide a detailed genomic analysis of this strain of the PSU9449 genome, an isolate obtained from a patient at Songklanagarind Hospital, Thailand. : Whole-genome sequencing (WGS) and bioinformatics analysis were employed to examine the genomic features of PSU9449. We performed sequence type (ST) determination through multilocus sequence typing (MLST), identified antimicrobial resistance genes (ARGs), virulence factor genes (VFGs), and analyzed the presence of mobile genetic elements (MGEs). Additionally, we compared the PSU9449 genome with strains from neighboring countries to understand its phylogenetic relationship. : The PSU9449 genome contained five insertion sequences and several ARGs, including , , , and . It also harbored VFGs related to flagella (, , and ), the type 6 secretion system (, , and ), and the type 3 secretion system (, , and ). MLST identified PSU9449 as ST3777, which was reported in Thailand for the first time. Phylogenetic analysis based on core gene SNPs revealed that PSU9449 was closely related to HW001G from Malaysia and MyJU45 from Myanmar, forming a distinct clade. : This study presents a comprehensive genomic analysis of PSU9449, shedding light on its genetic characteristics, antimicrobial resistance profile, and virulence potential. Interestingly, ST3777, the novel STs from the published genomes of in Thailand, were assigned in this study. The findings enhance valuable insights into the expanding knowledge of PSU9449 and highlight the importance of ongoing surveillance of its genetic diversity.