A virulent strain of antibiotic-resistant bacteria causing severe disease could sweep across Asia and become a serious global public health issue in the form of a new study, scientists warn. As part of their study of how bundled infection prevention and control (IPC) measures can impede the spread of Carbapenem-resistant Acinetobacter baumannii (CRAB), researchers stumbled upon the ST164 variant of CRAB in a Chinese intensive care unit (ICU). For 80.9%, the A. baumannii found in the ICU in Hangzhou throughout three months in 2021 was CRAB with ST164 accounting for 40.2% of samples.
According to the research published in Nature Communications, suggested that other hospital wards and transferred patients may serve as sources for new CRAB strains entering the ICU. The team’s previous research at the Hangzhou ICU in 2019 found that almost one-third of the patients were infected by CRAB.
According to the latest research, one strain type (GC2) of CRAB isolates fell from 99.5% in 2019 to 50.8% in 2021. Among the remaining population resides a set of ST164 isolates evolving since mid-2020 and with twice the level of measurable resistance to carbapenems than the GC2 strains measure. “We suspect ST164 is becoming established in ICU settings and is spreading widely in Asia,” commented Professor Alan McNally, co-author from the University of Birmingham. The levels of antibiotic resistance in ST164 mean it is something to watch because it infected fewer people than GC2 during this time of the study.
CRAB is a serious potential risk to hospitalized patients, leading to very severe diseases including pneumonia, urinary tract infection, bacteremia, meningitis, and soft tissue infections. “Controlling these bacteria’s spread within hospitals requires ongoing IPC measures, and we also need further research to understand how these strains evolve in hospital environments,” said Kawasaki. In this study, we used high-resolution whole genome sequencing and a comparative analysis of CRAB isolates.
CRAB can remain on hospital surfaces and equipment for long periods and can colonize patients in as few as 48 hours following admission—aided by hospital bed staff, shared equipment, ventilation, and plumbing. Addressing CRAB outbreaks requires interventions or even changes needed in infrastructure that impose clinical, logistical, and financial burdens.
CRAB infections are a global concern with extremely limited treatment options. The World Health Organization (WHO) classifies the CRAB as a priority organism which requires new therapeutics. The health implications of CRAB are extensive, including the ST164 clone, which has a profound impact on patient outcomes, health care systems, and public health globally, according to co-author Professor Willem van Schaik of the University of Birmingham.
In the absence of new therapeutic agents that tightly control the succession of CRAB IPC, our only defense becomes effective CRAB IPC strategies that limit morbidity and mortality from the bacteria in hospitals. Our study also shows how genomic surveillance can be used to trace the spread of this drug-resistant clone.
Reference: Liu H, Moran RA, Doughty EL, et al. Longitudinal genomics reveals carbapenem-resistant Acinetobacter baumannii population changes with the emergence of highly resistant ST164 clone. Nature Communications. 2024;15(1). doi: https://doi.org/10.1038/s41467-024-53817-xÂ
