Epidemiological characteristics of multidrug-resistant Acinetobacter baumannii ST369 in Anhui, China.

is of growing concern for global health owing to its ability to evade the immune system and develop resistance to antibiotics. We analyzed using the National Center for Biotechnology Information (https://www.ncbi.nlm.nih.gov/pathogens) database and observed that the ST369 strain isolated in China constituted over 50% of the globally prevalent ST369 clones. This finding highlights the significant impact of ST369 on public health in China. In this study, we examined eight strains of multidrug-resistant ST369 isolated from a provincial hospital in China. We conducted whole-genome sequencing, comparative genomic analysis, and phenotypic experiments, and used the infection model to achieve a comprehensive understanding of the organism. In our study, we identified two mutations, G540A and G667D, on the gene of ST369 that can potentially affect bacterial virulence and viscosity. We also verified the impact of these mutations on virulence and resistance. In addition, we examined two proteins, AB46_0125 and AB152_03903, which may play a role in virulence. These findings establish a foundation for future studies on clinical ST369 isolates harboring such mutations. IMPORTANCE is a major health threat due to its antibiotic resistance and ability to cause nosocomial infections. Epidemiological studies indicated that the majority of globally prevalent ST369 clones originated from China, indicating a significant impact on public health in the country. In this study, we conducted whole-genome sequencing, comparative genomics, and infection model on eight ST369 isolates collected from a provincial hospital in China to comprehensively understand the organism. We identified two mutations (G540A and G667D) on the gene that can affect bacterial virulence and viscosity. We confirmed their impact on resistance and virulence. We also investigated the potential involvement of AB46_0125 and AB152_03903 proteins in virulence. This finding provides a theoretical reference for further research on ST369 clinical isolates with similar mutations.