Healthcare Hygiene magazine August 2020 | Page 33

Here is what a microbial jungle might look like: The CDC’s list of ESKAPE Pathogens can be accessed at: View list of ESKAPE Pathogens Biofilms Biofilms are densely packed communities of microbial cells that grow on living or inert surfaces and surround themselves with secreted polymers. Many bacterial species form biofilms, and their study has revealed them to be complicated and diverse. The structural and physiological complexity of biofilms has led to the idea that they are coordinated and cooperative groups, analogous to multicellular organisms. Current research and studies conducted by scientists at Cardiff University, Dr. Katarzyna Ledwoch and professor Jean-Yves Maillard, introduce us to the latest in another type of biofilm, dry surface biofilms (DSB). DSB are complex microbial communities formed and grown in dry habitats. SEM image of DSB containing mixed hospital culture grown on stainless steel disc. Much less attention has been paid to dry biofilms compared to most commonly researched wet/hydrated biofilms. DSB colonize various materials from textile (chair), hard surfaces including plastic (PVC, PP), lacquered wood, wood, metal (stainless steel) to many others. DSB have been isolated from diverse environmental conditions: low moisture, varying temperature and nutrient levels. Biofilm is the invisible film that is present and growing on almost all surfaces in hospitals, restaurants, cruise ships, entertainment venues, hotels, and homes. It is the accumulation of microorganisms and their numerous chemical components. Whenever people are, they add to the already existing jungle of germs. Real-world hospital testing for dry biofilm presence and removal was most notably conducted by Ledwoch, et al., scientists at the School of Pharmacy and Pharmaceutical Sciences at Cardiff University and published is three articles: Candida auris Dry Surface Biofilm (DSB) for Disinfectant Efficacy Testing (2018); Beware biofilm! Dry biofilms containing bacterial pathogens on multiple healthcare surfaces: a multicenter study (2018): and Artificial dry surface biofilm models for testing the efficacy of cleaning and disinfection (2019). The results shared by Ledwoch, et al. as to the efficacy of various microfiber wipes and wipers by EVS staff categorically documented the effectiveness and superiority of Healthcare-Grade Ultrafine Microfiber (H-GUM) in the physical removal of dry biofilm. This type of microfiber was the only beneficial cloth to effect physical disruption of biofilm, be it wet or dry. H-GUM is constructed of split bi-component fibers and split to such fine triangular filaments. It disrupts the physical condition of biofilm to such an extent that the biofilm is removed. Bacteria itself contribute to the microbial jungle through waste products. Bacterial waste products are endotoxins, exotoxins, cellular debris, proteins, lipids (fats), and mucopolysaccharides (known in the microbiological trade as germ snot!). If the jungle floors of Central and South America were casually looked at, they would appear similar, yet they are vastly different. They are different because of the variety of flora and fauna living and dying there and are teeming with organic waste and infinite microbes and bacteria. One would also find moist and dry surface biofilm (DSB) serving as a festering microbial breeding ground and germ graveyard, the equivalent of the sludge found in septic tanks. Just as jungles from different parts of the world are different, the “jungles” found in hospitals are different because of where they are. Get the picture? Planktonic (1) Attachment to surface Why DSB Can Be a Problem ●DSB are widespread on surfaces in hospitals ●DSB contribute to pathogens survival and HAIs despite cleaning and disinfection ●DSB cannot be detected by swabbing or contact plates ●All biofilms harbor Gram-positive bacteria, including pathogens associated with HAIs ●DSB regrow within one day when provided with nutrients How to solve the problem: (5) Detachment and reversion to planktonic growth, starting new cycle (2) Formation (3) Microcolony ➜ of monolayer ➜ formation, ➜ and production multi-layer of matrix Biofilm (4) Mature biofilm, with characteristic “mushroom” formed of polysaccharide View Why DSB Problem ●Improved hand hygiene ●Improved cleaning with Healthcare Grade Ultrafine Microfiber (HGUM)© ●Disinfectants targeting DSB ●Improved monitoring of contamination levels Know the Enemies The complexity of the healthcare-associated microbial jungle requires accurate, reliable reproducible testing. The key to effective testing requires a standardized sample collection and testing procedure. The results acquired represent a precise picture of www.healthcarehygienemagazine.com • august 2020 33