A QUT-led pilot study has shown the use of a relatively simple and cost-effective method of monitoring the presence of infectious disease-causing bacteria in intensive care units and their sites of transmission.
New technique to sample high-touch areas and identify pathogens
Study found the method reveals 'hot spots' for dangerous hospital infection transmission
The method is money-saving and indicates improved infection control and cleaning of risk areas
The collaborative project between QUT, University of Southern Queensland, University of Queensland and St Vincent's Private Hospital in Toowoomba has demonstrated the power of academia and hospitals working together to address the critical problem of hospital-acquired infections.
Professor Kirsten Spann (pictured) from QUT's School of Biomedical Sciences said the researchers studied the use of plate sweeps to sample areas in a newly built eight-bed ICU in Toowoomba before and after patients were introduced to the area.
First author, research assistant Aasha McMurray-Jones said plate sweeps could help hospitals identify hidden risks and transmission hotspots early, enabling proactive measures to prevent outbreaks of dangerous, drug-resistant infections.
"A plate sweep is the process by which we swab high-touch hospital surfaces, such as door handles and medical equipment, and then grow the bacteria on the swab in shallow round dishes which contain a jelly-like substance that helps them grow," Ms McMurray-Jones said.
"Then we scrape everything off the dish and extract DNA from this mixed sample for sequencing and identification."
Professor Spann said healthcare-associated infections in Australia had almost doubled in recent years with antibiotic resistance making them harder and more expensive to treat.
"Hospitals need regular and rigorous surveillance of their environmental microbiome and pathogen transmission, particularly in ICUs where patients are more vulnerable, to help prevent these dangerous infections with improved infection control and cleaning processes," she said.
"We sampled from 78 sites in the ICU area both before and after the first patients arrived in patients' rooms.
"This included communal surfaces in reception, the laundry trolley and door handles; and plumbing-related areas – sinks, toilets, showers and drains."
Dr Leah Roberts said that after patients were introduced the ICU environment had changed completely - new bacterial species had appeared, including pathogens like Pseudomonas, Klebsiella, and Staphylococcus, and antimicrobial resistance genes had increased significantly.
"We found plumbing was the major source for bacteria and the plate sweep information allowed us to identify shared bathrooms as hotspots for ongoing bacterial transmission around the ICU," she said
"This study shows that plate sweeps can provide a practical approach to cultivating a wide range of bacteria to capture more species diversity than a single colony pick, without the high sequencing costs."
Dr Roberts said this technique could be used to identify areas at risk of causing hospital-acquired infections.
"Implementing this type of surveillance is cost effective and accurate enough for routine use to identify target areas for additional infection control measures before an outbreak occurs," she said.
Director of Intensive Care at St Vincent's Private Hospital Toowoomba, Dr Jeremy Fernando, said the hospital was presented with a rare opportunity in November 2023 with the opening of the new ICU to have the QUT team assess how a new unit changed with normal clinical activity after its opening.
"Given that it was a new ICU, we thought it was a unique opportunity to have QUT study what happens with the inevitable build-up of environmental microbiomes and pathogens," Dr Fernando said.
"We know that around the world – and we're no different – that no matter how diligent a hospital is with its cleaning, increasingly ICUs are seeing more infectious disease-causing bacteria which is drug-resistant which can be serious for patients.
"Ideally this study will add to the body of knowledge around how ICUs could change their processes and can help to inform how they are managed."
The research team comprised Professor Spann and Aasha McMurray-Jones from QUT; Professor Prasad Yarlagadda from the University of Southern Queensland; Dr Jeremy Fernando from St Vincent's Private Hospital Toowoomba; and Dr Leah Roberts from QUT and The University of Queensland.
The study, Environmental Surveillance of Bacteria in a New Intensive Care Unit using Plate Sweeps, was published in Microbial Genomics.
