Researchers discovered the carbapenem-resistant Acinetobacter baumannii (CRAB) variant ST164 in a Chinese intensive care unit (ICU) as part of their study on how combined infection prevention and control (IPC) measures affected the spread of CRAB.

Over a three-month period in 2021, experts conducted extensive genomic surveillance, within the Hangzhou ICU, and revealed that 80.9% of bacteria or A. baumannii found in patients were CRAB, and ST164 represented 40.2% of the samples.

Publish your findings on nature communications, Researchers from the University of Birmingham and Zhejiang University reveal that other hospital wards and transferred patients could be sources of new CRAB strains entering the ICU.

The study follows the team’s previous research in Hangzhou ICU in 2019, which showed that almost a third of patients were infected with CRAB.

Latest research shows that one type of strain (GC2) among CRAB isolates fell from 99.5% in 2019 to 50.8% in 2021. The remaining population was mainly composed of ST164 isolates that have been evolving since mid-2020 and have twice the levels of measurable resistance to carbapenems. that the GC2 strains have.

Co-author Professor Alan McNally, from the University of Birmingham, commented: “We believe that ST164 is becoming established in ICU settings and may be spreading widely across Asia. While ST164 caused fewer infections than GC2 during the study period, its highs levels of antibiotic resistance indicate that it needs careful monitoring.

“CRAB poses a serious risk to hospitalized patients and can cause serious illnesses, such as pneumonia, urinary tract infection, bacteremia, meningitis and soft tissue infections. Ongoing IPC measures are vital to control the spread of these bacteria within of hospitals and more research is needed to understand how these bacteria evolve in hospital environments.

The research was funded by the Medical Research Council and the National Natural Science Foundation of China. The study involved high-resolution whole-genome sequencing and comparative analysis of CRAB isolates.

CRAB can persist for prolonged periods on hospital surfaces and medical equipment and colonize patients within 48 hours of admission, all facilitated by hospital staff, shared equipment, airflow, and pipes. CRAB outbreaks may require interventions or infrastructure changes that impose clinical, logistical, and financial burdens.

Antibiotic-resistant infections are a major threat to global public health. CRAB infections are found worldwide with very limited treatment options, prompting the World Health Organization to designate CRAB as a priority organism for which new therapies are urgently needed.

Co-author Professor Willem van Schaik, from the University of Birmingham, added: “The health implications of CRAB, especially the ST164 clone, are profound and affect patient outcomes, healthcare systems and public health across the world. In the absence of new therapeutic agents “Effective CRAB IPC strategies are vital if we want to limit the morbidity and mortality caused by the bacteria in hospitals. “Furthermore, our study illustrates the power of genomic surveillance to map the emergence and spread of this drug-resistant clone.”