Burkholderia in ICU – a combined epidemiologic, genomic and engineering investigation
Vivian Leung1,2,3, Matthew Richards1, Elizabeth Orr1, Christopher MacIsaac4,5, Adam Steegstra6, Caroline Marshall1,2,3
1Infection Prevention and Surveillance Service, Royal Melbourne Hospital, Parkville, Victoria, Australia
2Victorian Infectious Diseases Services, Royal Melbourne Hospital, Parkville, Victoria, Australia
3Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
4Intensive Care Unit, Royal Melbourne Hospital, Parkville, Victoria, Australia
5Department of Critical Care, The University of Melbourne, Parkville, Victoria, Australia
6Facilities Management, Royal Melbourne Hospital, Parkville, Victoria, Australia
Introduction
Burkholderia species are known environmental pathogens which can cause significant illness, particularly in hospitalized immunocompromised populations and intensive care settings. We describe a combined epidemiologic, genomic and engineering investigation of intermittent clusters of Burkholderia from clinical and environmental samples in the intensive care unit (ICU) of Royal Melbourne Hospital.
Methods
All ICU patients with Burkholderia identified in clinical samples from microbiology records between April 2017 and December 2022 were investigated. Environmental samples were collected from faucets in ICU after Burkholderia was detected in a patient. Burkholderia isolates underwent molecular and whole genome sequencing. Taps where Burkholderia was isolated underwent thermal disinfection. The existing chlorination program was reviewed.
Results
Twenty-nine patients were Burkholderia positive, with isolates from respiratory samples (n=19, 65%) most common. A total of 275 environmental samples were collected across all ICU pods, of which 37 (13%) grew Burkholderia. Molecular sequencing identified diverse sequence types across clinical and environmental samples. One probable episode of environment to patient transmission was identified. Variable water chlorine levels within ICU were detected, ranging from acceptable to non-detectable.
Conclusion
Isolation of Burkholderia from tap water in all ICU pods suggests presence of biofilm that intermittently releases organisms into the water. Dispersal of organisms from taps to patient can occur through a variety of mechanisms. It is unknown if low chlorine levels are associated with presence of organisms in the tap water. Combining epidemiology and genomic data to identify the source of potential contamination is important for risk mitigation and prevent further Burkholderia cases.
Biography
Matt is a clinical nurse consultant employed with the Infection Prevention and Surveillance Service at the Royal Melbourne Hospital, Melbourne. He has been working with the IPSS team since 2007 and has led the HAI surveillance program since then, building solid connections with key stakeholders and leading to positive outcomes for patients. More recently, he has taken up a role with the University of Melbourne one day a week providing expert infection control advice for a research project: Preparing Fiji for pathogens with critical antimicrobial resistance.