Antibiotic-resistant bacteria can pose a major health threat throughout Asia

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

Over a three-month period in 2021, the experts conducted extensive genomic surveillance at the ICU in Hangzhou, which revealed that 80.9% of A. baumannii bacteria found in patients were CRAB, with ST164 responsible for 40.2% of samples.

Publish their findings in Nature communication, 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 previous research by the team at Hangzhou ICU in 2019, which found that almost a third of patients were infected with CRAB.

The latest research shows that one strain type (GC2) among CRAB isolates has decreased from 99.5% in 2019 to 50.8% in 2021. The remaining population consisted mainly of ST164 isolates that have evolved since mid-2020 and have twice as much measurable resistance to carbapenems. that the GC2 strains have.

Co-author Professor Alan McNally, from the University of Birmingham, commented: “We believe ST164 is becoming well established in intensive care units and may spread widely across Asia. Although ST164 caused fewer infections than GC2 during the study period, the high levels of ST164 antibiotic resistance indicate that careful monitoring is needed.

“CRAB poses a serious risk to hospitalized patients and can cause serious illness, including pneumonia, urinary tract infection, bacteremia, meningitis and soft tissue infections. Continued IPC measures are critical to controlling the spread of these bacteria within hospitals and further research is needed to understand how these bacteria spread. strains evolve in hospital environments.”

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

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

Antibiotic-resistant infections pose a major threat to global public health. CRAB infections are found worldwide with very limited treatment options, leading 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 impact outcomes for patients, healthcare systems and public health worldwide. In the absence of new therapeutic agents, effective CRAB IPC strategies are vital if we want to limit 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.