Universal versus targeted chlorhexidine and mupirocin decolonisation and clinical and molecular epidemiology of Staphylococcus epidermidis bloodstream infections in patients in intensive care in Scotland, UK: a controlled time-series and longitudinal genotypic study

Area of Science:

• Infectious Diseases
• Intensive Care Medicine
• Microbiology
• Antimicrobial Resistance

Background:

• Widespread use of biocide skin and mucous membrane decolonisation in intensive care units (ICUs) aims to prevent health-care-associated infections.
• Concerns exist that this practice may inadvertently select for multidrug-resistant pathogens.
• This study investigates the impact of reducing universal decolonisation to targeted decolonisation on Staphylococcus epidermidis bloodstream infections (SE-BSI).

Purpose of the Study:

• To evaluate the effects of de-escalating from universal to targeted skin and nasal decolonisation strategies.
• To assess the impact on Staphylococcus epidermidis bloodstream infections (SE-BSI), particularly meticillin-resistant S. epidermidis (MRSE-BSI).
• To analyze genotypic changes in S. epidermidis isolates associated with decolonisation practices.

Main Methods:

• Retrospective, before-after-control-impact time-series analysis and longitudinal genotypic study in two ICUs.
• Comparison of universal decolonisation (de-escalated to targeted) versus continuous targeted decolonisation.
• Analysis of bloodstream infection data, antimicrobial susceptibility, multilocus sequence typing, and whole-genome sequencing.

Main Results:

• No increase in overall bloodstream infections observed after de-escalation in the intervention ICU.
• Significant decline in MRSE-BSI incidence density and the probability of SE-BSI being MRSE-BSI following de-escalation.
• De-escalation associated with reduced proportion of multidrug-resistant SE-BSI and decreased carriage of resistance and biofilm genes.

Conclusions:

• De-escalating universal decolonisation to targeted decolonisation can reduce MRSE-BSI incidence in ICUs with low MRSA prevalence.
• This strategy may mitigate the selection of MRSE strains adapted for invasive and device-associated infections.
• Balancing the benefits of universal decolonisation against the risks of promoting antimicrobial resistance is crucial.