Transfer of dry surface biofilm in healthcare environment: the role of healthcare worker's hands as vehicles (original) (raw)
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Transmission of Staphylococcus aureus from dry surface biofilm (DSB) via different types of gloves
Infection Control & Hospital Epidemiology, 2018
BackgroundPathogens can survive for extended periods when incorporated into biofilm on dry hospital surfaces (ie, dry-surface biofilm, DSB). Bacteria within biofilm are protected from desiccation and have increased tolerance to cleaning agents and disinfectants.ObjectiveWe hypothesized that gloved hands of healthcare personnel (HCP) become contaminated with DSB bacteria and hence may transmit bacteria associated with healthcare-associated infections (HAIs).Method Staphylococcus aureus DSB was grown in vitro on coupons in a bioreactor over 12 days with periodic nutrition interspersed with long periods of dehydration. Each coupon had ~107 DSB bacterial cells. Transmission was tested with nitrile, latex, and surgical gloves by gripping DSB-covered coupons then pressing finger tips onto a sterile horse blood agar surface for up to 19 consecutive touches and counting the number of colony-forming units (CFU) transferred. Coupons were immersed in 5% neutral detergent to simulate cleaning, ...
Journal of Microbiological Methods, 2015
The environment has been shown to be a source of pathogens causing infections in hospitalised patients. Incorporation of pathogens into biofilms, contaminating dry hospital surfaces, prolongs their survival and renders them tolerant to normal hospital cleaning and disinfection procedures. Currently there is no standard method for testing efficacy of detergents and disinfectants against biofilm formed on dry surfaces. Aim: The aim of this study was to develop a reproducible method of producing Staphylococcus aureus biofilm with properties similar to those of biofilm obtained from dry hospital clinical surfaces, for use in efficacy testing of decontamination products. The properties (composition, architecture) of model biofilm and biofilm obtained from clinical dry surfaces within an intensive care unit were compared. Methods: The CDC Biofilm Reactor was adapted to create a dry surface biofilm model. S. aureus ATCC 25923 was grown on polycarbonate coupons. Alternating cycles of dehydration and hydration in tryptone soy broth (TSB) were performed over 12 days. Number of biofilm bacteria attached to individual coupons was determined by plate culture and the coefficient of variation (CV%) calculated. The DNA, glycoconjugates and protein content of the biofilm were determined by analysing biofilm stained with SYTO 60, Alexa-488-labelled Aleuria aurantia lectin and SyproOrange respectively using Image J and Imaris software. Biofilm architecture was analysed using live/dead staining and confocal microscopy (CM) and scanning electron microscopy (SEM). Model biofilm was compared to naturally formed biofilm containing S. aureus on dry clinical surfaces. Results: The CDC Biofilm reactor reproducibly formed a multi-layered, biofilm containing about 10 7 CFU/coupon embedded in thick extracellular polymeric substances. Within run CV was 9.5% and the between run CV was 10.1%. Protein was the principal component of both the in vitro model biofilm and the biofilms found on clinical surfaces. Continued dehydration and ageing of the model biofilm for 30 days increased the % of protein, marginally decreased gylcoconjugate % but reduced extracellular DNA by 2/3. The surface of both model and clinical biofilms was rough reflecting the heterogeneous nature of biofilm formation. The average maximum thickness was 30.74 ± 2.1 μm for the in vitro biofilm model and between 24 and 47 μm for the clinical biofilms examined. Conclusion: The laboratory developed biofilm was similar to clinical biofilms in architecture and composition. We propose that this method is suitable for evaluating the efficacy of surface cleaners and disinfectants in removing biofilm formed on dry clinical surfaces as both within run and between run variation was low, and the required equipment is easy to use, cheap and readily available.
Letters in Applied Microbiology, 2019
Significance and Impact of the Study: Contamination of healthcare facilities surfaces has been shown to play a major role in transmission of pathogens. The findings of this study show that dry surface biofilms are widespread and can incorporate pathogens and multidrug-resistant organisms (MROs). Biofilms on highly touched surfaces pose a risk to patients, as dry surface biofilms persist for long period and microorganisms within biofilm have been shown to be transmitted. This study also provides a better understanding of microbial populations in hospital environments, reinforcing that pathogens and MROs are found incorporated into biofilm, which impacts the difficulty in cleaning/disinfection.
Bacterial transfer to fingertips during sequential surface contacts with and without gloves
Indoor Air
The transmission of infection has significant economic and societal implications, but quantifying or establishing how pathogens are transmitted is often challenging due to complex interactions between air and surfaces, variability in behaviors, and difficulty detecting viable pathogens in indoor environments. 1-3 The transmission of multidrug-resistant Gram-negative bacilli is a significant problem in UK and US hospitals, and from May 2018 to 2019, there were 24 879 Escherichia coli (E coli) bacteremia hospital-onset
The Journal of hospital infection, 2015
Microbes tend to attach to available surfaces and readily form biofilms, which is problematic in healthcare settings. Biofilms are traditionally associated with wet or damp surfaces such as indwelling medical devices and tubing on medical equipment. However, microbes can survive for extended periods in a desiccated state on dry hospital surfaces, and biofilms have recently been discovered on dry hospital surfaces. Microbes attached to surfaces and in biofilms are less susceptible to biocides, antibiotics and physical stress. Thus, surface attachment and/or biofilm formation may explain how vegetative bacteria can survive on surfaces for weeks to months (or more), interfere with attempts to recover microbes through environmental sampling, and provide a mixed bacterial population for the horizontal transfer of resistance genes. The capacity of existing detergent formulations and disinfectants to disrupt biofilms may have an important and previously unrecognized role in determining the...
Surveillance of bacterial colonisation on contact surfaces in different medical wards
Arhiv za higijenu rada i toksikologiju, 2017
This study was conducted to determine the bacterial colonization of some bacterial groups, including extended-spectrum β-lactamase (ESBLs) producers and methicillin-resistant Staphylococcus aureus (MRSA), on surfaces of the equipment and instruments in patient rooms and other workspaces in three different medical wards. The number of microorganisms on swabs was determined with the colony count method on selective microbiological mediums. The aerobic mesophylic microorganisms were found in 73.5 % out of 102 samples, with the average and maximum values of 2.6 × 102 and 4.6 × 103 colony forming units (CFU) 100 cm-2, respectively. Members of the family Enterobacteriaceae, coagulase positive staphylococci, coagulase-negative staphylococci, and enterococci were detected in 23.4, 31.4, 53.2, and 2.9 % of samples, respectively. The differences in bacterial counts on the surfaces of the psychiatric, oncology, and paediatric wards were statistically significant (P<0.001). About 40 % out of...
An investigation of contact transmission of methicillin-resistant Staphylococcus aureus
Journal of Hospital Infection, 2004
Hand hygiene is critical in the healthcare setting and it is believed that methicillin-resistant Staphylococcus aureus (MRSA), for example, is transmitted from patient to patient largely via the hands of health professionals. A study has been carried out at a large teaching hospital to estimate how often the gloves of a healthcare worker are contaminated with MRSA after contact with a colonized patient. The effectiveness of handwashing procedures to decontaminate the health professionals' hands was also investigated, together with how well different healthcare professional groups complied with handwashing procedures. The study showed that about 17% (9 -25%) of contacts between a healthcare worker and a MRSA-colonized patient results in transmission of MRSA from a patient to the gloves of a healthcare worker. Different health professional groups have different rates of compliance with infection control procedures. Non-contact staff (cleaners, food services) had the shortest handwashing times. In this study, glove use compliance rates were 75% or above in all healthcare worker groups except doctors whose compliance was only 27%.
Infection Control and Hospital Epidemiology, 2008
Chemical disinfectants and antiseptics. Virucidal quantitative suspension test for chemical disinfectants and antiseptics used in human medicine-test method and requirements (phase 2, step 1). 2005. 8. European Standard EN 13610. Chemical disinfectants. Quantitative suspension test for the evaluation of virucidal activity against bacteriophages of chemical disinfectants used in food and industrial areas-test method and requirements (phase 2, step 1). 1999. 9. Sehulster LM, Chinn RYW; Centers for Disease Control (CDC); Healthcare Infection Control Practices Advisory Committee (HICPAC). Guidelines for Environmental Infection Control in Health-Care Facilities. Recommendations from the CDC and the HICPAC.
Efficiency and novelty of using environmental swabs for dry surface biofilm recovery
Studies on the epidemiology of dry surface biofilms within healthcare has shown an almost universal distribution across frequently touched items. Despite a growing body of evidence for dry surface biofilms in hospitals little attention has been paid to the recovery capacity of techniques used to detect these microbial communities. Biofilms are inherently difficult to remove from surfaces due to adhesive substances within their matrix and may act as sources of infection but to what extent is largely unknown. In this study we evaluate the recovery efficiencies of commonly used environmental swabs against dry surface biofilms containing 7.24-Log10 Acinetobacter baumannii/cm2, using a drip flow reactor and desiccation cycle. Biofilm presence was visually confirmed using episcopic differential interference contrast microscopy combined with epifluorescence and quantified using sonicated viable plate counts. The swab materials used comprised of foam, viscose and cotton, all of which were ...