The Silent Threat: Why Bloodstream Infections Demand Attention

Bloodstream infections (BSIs) remain one of the most lethal clinical challenges worldwide, claiming countless lives and complicating medical advancements. In China, the rise of immunocompromised patients—due to cancer therapies, organ transplants, and chronic diseases—has intensified this threat. Among the pathogens responsible, Acinetobacter baumannii stands out as a notorious "hospital superbug," causing BSIs with mortality rates exceeding 60% and exhibiting alarming resistance to antibiotics. Despite its severity, large-scale genomic studies to unravel its evolution and spread have been scarce—until now.

Our latest study, published in Nature Communications (Title: Genomic epidemiology and phylodynamics of Acinetobacter baumannii bloodstream isolates in China. https://www.nature.com/articles/s41467-025-58772-9 ), leverages a decade of data from the Blood Bacterial Resistant Investigation Collaborative System (BRICS). This work reveals critical insights into how A. baumannii is adapting, evolving, and outsmarting our defenses. Here’s the story behind the science.

Building BRICS: A National Shield Against Bloodstream Infections with Precious Data

In 2013, Prof. Yonghong Xiao (State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University, China) initiated BRICS—a nationwide antimicrobial resistance surveillance network—under the guidance of Prof. Lanjuan Li (Academician of the Chinese Academy of Engineering, Laboratory Director of State Key Laboratory for Diagnosis and Treatment of Infectious Diseases). Designed to track pathogens isolated from sterile body fluids (e.g., blood, cerebrospinal fluid), BRICS has grown into a collaborative platform uniting more than 60 hospitals across 25 provinces in China. Over the past 12 years, it has amassed over 70,000 bacterial isolates, creating the largest epidemiological repository for BSIs in China.

BRICS operates on principles of "voluntary participation, open access, and data sharing." Beyond surveillance, it fosters interdisciplinary collaboration among microbiologists, infectious disease specialists, and clinicians. Through its more than 20,000-member WeChat Official Account, annual resistance reports, and academic forums, BRICS has become a cornerstone for combating antimicrobial resistance (AMR) in China.

Decoding a Decade of A. baumannii’s Secret Warfare 

Using BRICS’s repository, we analyzed 1,506 non-repetitive A. baumannii isolates in 11 years. Key findings reveal a dramatic shift in the pathogen’s landscape, driven by the rise of a “super-clone”: sequence type 208 (ST208). Within the globally dominant International Clone 2 (IC2), which accounted for 81.74% of isolates, ST208 emerged as the leading strain, displacing earlier variants like ST191 and ST195. This mirrors global trends, suggesting ST208’s evolutionary advantage. Its success is attributed to enhanced virulence, hyper-resistance, and disseminated through multiple interprovincial transmission events. The study also underscores A. baumannii’s genomic plasticity. This genetic flexibility enables rapid acquisition of resistance and virulence traits, accelerating a microbial “arms race” and intensifying its threat. Alarmingly, the data indicate a paradigm shift from multidrug resistance to hypervirulence, with emerging strains like ST208 evolving into highly virulent, pan-resistant pathogens capable of causing severe infections even in immunocompetent hosts. 

    These findings have immediate implications for global health. ST208’s transmission patterns highlight infection control hotspots requiring targeted interventions, while resistance gene profiles underscore the urgency of stricter antibiotic stewardship. Additionally, conserved virulence factors present potential targets for vaccine development. Looking ahead, BRICS aims to expand real-time genomic surveillance using AI-driven platforms, integrate multi-omics data (transcriptomics, proteomics) to predict outbreak trajectories, and strengthen global partnerships to combat antimicrobial resistance (AMR), a threat that transcends borders.

The Power of Collaboration

This study would not have been possible without the synergy of interdisciplinary collaboration. The BRICS network provided rigorously curated isolates and epidemiological data, forming the backbone of our research. Meanwhile, the bioinformatics expertise of Professor Huaiqiu Zhu’s team at Peking University was instrumental in enabling high-throughput genomic analysis and evolutionary modeling. Their methodologies were pivotal in unraveling ST208’s dominance. Our team represents a unique blend of expertise in infectious disease, clinical microbiology, bioinformatics, and computational biology. This cross-disciplinary approach has been critical to our success and highlights the power of collaboration in tackling complex global health challenges.

Looking Ahead: From Genomes to Global Health

Moving forward, we aim to expand our efforts through real-time genomic surveillance powered by AI-driven platforms. By integrating multi-omics data (transcriptomics, proteomics), we hope to predict outbreak trajectories and develop more effective interventions. We also plan to strengthen global partnerships to combat antimicrobial resistance (AMR), a threat that transcends borders.

    Our journey from the BRICS network to the genomic insights published in Nature Communications underscores the importance of collaboration, innovation, and perseverance. We are committed to advancing research at the intersection of genomics, epidemiology, and public health, and we invite the global scientific community to join us in this critical mission. Together, we can turn the tide against formidable pathogens and safeguard patient lives worldwide.