Genomic epidemiology and phylodynamics of Acinetobacter baumannii bloodstream isolates in China
Qixia Luo, Mengru Chang, Ping Lu, Qian Guo, Xiaoqing Jiang, Tingting Xiao, Haoyu Zhang, Yingying Ma, Yan Zhang, Wei Yu, Erjia Zhang, Yunbo Chen, Ping Shen, Jinru Ji, Chaoqun Ying, Zhiying Liu, the BRICS Working Group, Yonghong Xiao, Yunbo Chen, Jinru Ji, Zhiying Liu, Chaoqun Ying, Qing Yang, Haishen Kong, Jiangqin Song, Hui Ding, Yanyan Li, Yuanyuan Dai, Haifeng Mao, Pengpeng Tian, Lu Wang, Yongyun Liu, Yizheng Zhou, Jiliang Wang, Yan Jin, Donghong Huang, Hongyun Xu, Peng Zhang, Xinhua Qiang, Hong He, Lin Zheng, Junmin Cao, Zhou Liu, Ying Huang, Yan Geng, Haiquan Kang, Dan Liu, Guolin Liao, Lixia Zhang, Fenghong Chen, Yanhong Li, Baohua Zhang, Haixin Dong, Xiaoyan Li, Donghua Liu, Qiuying Zhang, Xuefei Hu, Liang Guo, Sijin Man, Dijing Song, Rong Xu, Youdong Yin, Kunpeng Liang, Aiyun Li, Zhuo Li, Qiang Liu, Guoping Lu, Jinhua Liang, Qiang Liu, Yinjiao Dong, Jilu Shen, Shuyan Hu, Liang Luan, Jian Li, Ling Meng, Dengyan Qiao, Xiusan Xia, Bo Quan, Dahong Wang, Chunhua Han, Xiaoping Yan, Fei Li, Shifu Wang, Huaiqiu Zhu, Yonghong Xiao
Abstract
In recent decades, Acinetobacter baumannii has become a major global nosocomial pathogen, with bloodstream infections (BSIs) exhibiting mortality rates exceeding 60% and imposing substantial economic burdens. However, limited large-scale genomic epidemiology has hindered understanding of its population dynamics. Here, we analyzed 1506 non-repetitive BSI-causing A. baumannii isolates from 76 Chinese hospitals over a decade (2011–2021). We identified 149 sequence types (STs) and 101 K-locus types (KLs), revealing increased population diversity. International clone (IC) 2 accounted for 81.74% of isolates, with a notable shift in prevalent STs: ST208 increased while ST191 and ST195 declined, aligning with global trends. ST208 exhibited higher virulence, greater antibiotic resistance, enhanced desiccation tolerance, and more complex transmission patterns compared to ST191 and ST195. Its genomic plasticity drives its adaptation and spread. Using the high-resolution Oxford MLST scheme, this study uncovered greater diversity and genetic factors behind ST208’s rise. A. baumannii is evolving from a low-virulence, multidrug-resistant pathogen to a more virulent one, highlighting the urgent need to address its growing threat. These findings have critical implications for infection control and public health policies. The genomic epidemiology of Acinetobacter baumannii, which is rising in virulence and multidrug resistance, was explored. This study examined bloodstream infection isolates from Chinese patients in 2011–2021, revealing increased genetic diversity and dominance of highly virulent ST208.