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Whole-genome sequencing shows that patient-to-patient transmission rarely accounts for acquisition of Staphylococcus aureus in an intensive care unit
journal contribution
posted on 2023-06-08, 18:18 authored by James R Price, Tanya Golubchik, Kevin Cole, Daniel J Wilson, Derrick W Crook, Guy E Thwaites, Rory Bowden, A Sarah Walker, Timothy E A Peto, John Paul, Martin LlewelynMartin LlewelynBACKGROUND Strategies to prevent Staphylococcus aureus infection in hospitals focus on patient-to-patient transmission. We used whole-genome sequencing to investigate the role of colonized patients as the source of new S. aureus acquisitions, and the reliability of identifying patient-to-patient transmission using the conventional approach of spa typing and overlapping patient stay. METHODS Over 14 months, all unselected patients admitted to an adult intensive care unit (ICU) were serially screened for S. aureus. All available isolates (n = 275) were spa typed and underwent whole-genome sequencing to investigate their relatedness at high resolution. RESULTS Staphylococcus aureus was carried by 185 of 1109 patients sampled within 24 hours of ICU admission (16.7%); 59 (5.3%) patients carried methicillin-resistant S. aureus (MRSA). Forty-four S. aureus (22 MRSA) acquisitions while on ICU were detected. Isolates were available for genetic analysis from 37 acquisitions. Whole-genome sequencing indicated that 7 of these 37 (18.9%) were transmissions from other colonized patients. Conventional methods (spa typing combined with overlapping patient stay) falsely identified 3 patient-to-patient transmissions (all MRSA) and failed to detect 2 acquisitions and 4 transmissions (2 MRSA). CONCLUSIONS Only a minority of S. aureus acquisitions can be explained by patient-to-patient transmission. Whole-genome sequencing provides the resolution to disprove transmission events indicated by conventional methods and also to reveal otherwise unsuspected transmission events. Whole-genome sequencing should replace conventional methods for detection of nosocomial S. aureus transmission.
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Publication status
- Published
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- Published version
Journal
Clinical Infectious DiseasesISSN
1058-4838Publisher
University of Chicago PressExternal DOI
Issue
5Volume
58Page range
609-618Department affiliated with
- Global Health and Infection Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2014-09-15First Open Access (FOA) Date
2016-03-22First Compliant Deposit (FCD) Date
2016-11-10Usage metrics
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