Related Experiment Video
Updated: Jan 12, 2026
Microtiter Dish Biofilm Formation Assay
Published on: January 30, 2011
Enterococcus spp. ability to form a dry surface biofilm: a route to persistence on environmental surfaces
R Harsent1, V Cattoir2, M Pascoe1
1School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK.
Background:
Healthcare-associated infections (HAIs) present a significant global burden, with resistant pathogens such as vancomycin-resistant enterococci (VRE) being of particular concern. Dry surface biofilms (DSBs) have recently emerged as critical reservoirs for multi-drug-resistant organisms in healthcare environments, yet little is known about enterococcal DSB formation and persistence.
Aim:
This study aimed to evaluate the ability of various Enterococcus species and clinical isolates to form DSBs on healthcare-relevant materials, assess their long-term survival, and explore factors influencing DSB culturability.
Methods:
Multiple enterococcus strains, including epidemic and vancomycin-resistant isolates, were cultured using a standardized DSB formation model on a range of surfaces and materials commonly found in healthcare settings. Culturability was assessed through serial dilutions and colony enumeration. Structural characterization was performed via scanning electron microscopy (SEM), confocal microscopy and flow cytometry.
Findings:
All enterococcus strains formed DSBs on stainless steel and other clinical materials. DSBs maintained high culturability (5-6 log10) for up to 84 weeks at 20 °C and 55% relative humidity. VRE strains exhibited lower culturability compared with non-VRE. No correlation was found between DSB formation and surface roughness or hydrophobicity. SEM, confocal imaging and flow cytometry confirmed heterogeneity in DSB structure and viability across surfaces.
Conclusion:
Enterococcus spp. can form persistent, viable DSBs on diverse healthcare surfaces, contributing to the environmental persistence of pathogens. The combination of mechanical removal with an effective disinfectant remains at present the best approach for DSB control on hard surfaces. As such, enhanced cleaning and disinfection might be, for the time being, the best approach to control DSBs on hard surfaces.
Insights
Enterococcus species form persistent dry surface biofilms (DSBs) on healthcare surfaces for over 84 weeks. Enhanced cleaning and disinfection are currently the best methods to control these resilient pathogen reservoirs.
Area of Science:
- Microbiology
- Infectious Diseases
- Environmental Health
Background:
- Healthcare-associated infections (HAIs) are a major global health concern, exacerbated by multidrug-resistant organisms like vancomycin-resistant enterococci (VRE).
- Dry surface biofilms (DSBs) are emerging reservoirs for pathogens in healthcare settings, but their formation and persistence by enterococci are poorly understood.
Purpose of the Study:
- To investigate the capacity of various Enterococcus species to form DSBs on common healthcare materials.
- To assess the long-term viability and culturability of these enterococcal DSBs.
- To explore factors influencing DSB formation and persistence.
Main Methods:
- A standardized DSB model was used to culture multiple enterococcus strains, including VRE, on various healthcare surfaces.
- Culturability was determined by serial dilutions and colony counts.
- Scanning electron microscopy (SEM), confocal microscopy, and flow cytometry were employed for structural and viability analyses.
Main Results:
- All tested enterococcus strains successfully formed DSBs on stainless steel and other clinical materials.
- DSBs remained highly culturable for up to 84 weeks under controlled conditions (20°C, 55% RH).
- VRE strains showed reduced culturability compared to non-VRE strains; no correlation was found between DSB formation and surface properties.
Conclusions:
- Enterococcus species form persistent and viable DSBs on diverse healthcare surfaces, contributing to pathogen environmental persistence.
- Mechanical removal combined with effective disinfection is the current optimal strategy for controlling enterococcal DSBs on hard surfaces.
Related Concept Videos
01:29Biofilms
01:18Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...