In what settings do MRSA skin infections occur?
• MRSA skin infections can occur anywhere.
• Some settings have factors that make it easier for MRSA to be transmitted.
• These factors, referred to as the 5 Cs, are as follows: Crowding, frequent skin-to-skin Contact, Compromised skin (i.e., cuts or abrasions), Contaminated items and surfaces, and lack of Cleanliness.
CDC
By Allen Rathey
Cleaning is the removal of unwanted matter, including macro soil we can see: dirt, debris, and spills; and micro soil: harmful bacteria, viruses, spores, dust particles, and chemical substances below the threshold of human perception. Micro soils, with their ability to enter the human body, often have a major impact on health, and require critical emphasis during cleaning. How do you know when you have effectively removed these micro-soils that can endanger human health? In a word: measurement.
Following is an overview of three types of devices that can help validate a hygienic cleaning program focused on microbial and fungal micro-soil removal. Each device detects ‘markers’ that identify a certain micro-contaminant, for example, ATP testers determine the presence of adenosine triphosphate which is present in organic matter (bacteria, yeast, mold, food residue, etc.) to determine overall bio-soiling; biodetectors determine or utilize the presence of antibodies, enzymes, DNA, and other components of particular living organisms; and mold detectors detect fungal enzymes as indicators of the presence of mold.
ATP Devices
ATP is the most widely recognized and accessible marker, since it enables the broadest assessment of the presence of organic soils. According to Hygiena, a leading manufacturer of ATP testing devices:
“ATP (adenosine triphosphate) is present in ... organic material, and is the universal unit [or currency] of energy used in all living cells. ATP is produced and/or broken down in metabolic processes in all living systems. Processes such as photosynthesis in plants, muscle contraction in humans, respiration in fungi and fermentation in yeast are all driven by ATP. Therefore, most foods and microbial cells will contain some level of naturally occurring ATP. The [ATP device] uses bioluminescence to detect residual ATP as an indicator of surface cleanliness. The presence of ATP on a surface indicates … the presence of [bio]contamination, including food residue, allergens and/or bacteria … [and] potential for the surface to support bacterial growth.”
ATP results are inconsistent, however, when testing surfaces of organic nature (e.g., unfinished wood) because those surfaces have varying innate levels of ATP. “Background ATP levels can vary among building materials,” said Dr. Gene Cole, Professor of Environmental Health Sciences, Brigham Young University, “thus the method must be researched according to a specific cleaning approach, the materials and surfaces to be cleaned, and the desired outcome (i.e. acceptability), in order to enhance interpretation.”
Tiled restrooms, stainless steel and tiled foodservice areas, and laminated desktops as found in schools, are ideal for ATP testing since they have no inherent ATP to skew readings.
According to Forensic Sanitarian, Dr. Robert W. Powitz, who holds a Masters in Public Health, with a specialty in institutional practice, and a PhD in environmental health from the University of Minnesota: “The more I use ATP testing in my work, and the more I explain its operational capabilities and limitations to my clients, the greater is our collective level of comfort in using it to define and set reasonable guidelines and standards for cleanliness.”
ATP-based and/or Petri-film based cleaning protocols are currently in development by several industry consultants and KaiScience, supported by Kaivac (a leading backer of cleaning industry research), and will include:
1. Flat Surface Cleaning (FSC) Protocol (Above Floor)
2. Hard Floor Cleaning (HFC) Protocol
3. Uneven Surface Cleaning (USC) Protocol (Above Floor)
Preliminary results data based on the initial tested cleaning protocols are encouraging:
ATP Counts - Reported in Relative Light Units (RLUs)
Flat Surface Cleaning (FSC) Protocol (Above Floor)
Note: The FSC Protocol (using KaiFly, manufactured by Kaivac, Hamilton OH) was compared to MF (standard microfiber towel) in cleaning a flat surface (table).
FSC Protocol vs. Microfiber (MF) Towel
• FSC Protocol reduced a 6936 RLU count to 28 RLUs
• MF Towel reduced a 6907 RLU count to 768 RLUs
Hard Floor Cleaning (HFC) Protocol
Note: The HFC Protocol (using a spray-and-vac machine, manufactured by Kaivac, Hamilton OH) was compared to MF (standard microfiber mop).
HFC Protocol vs. Microfiber (MF) Mop
• HFC Protocol reduced a 7844 RLU count to 27 RLUs
• MF Mop reduced a 7267 RLU count to 1479 RLUs
Petri Film Counts – Reported in Colony Forming Units (CFUs)
Uneven Surface Cleaning (USC) Protocol (Above Floor)
Note: The USC Protocol (using KaiWipes, manufactured by Kaivac, Hamilton OH) was compared to standard cleaning Cloths.
Petri film was used to test for CFUs (colony forming units). The bacterial counts in CFUs for the USC Protocol vs. Cloths (both using identical disinfectant):
• Average CFU/ sq in after cleaning was 1.8 for USC vs. 6.3 for Cloth (Cloth left 3.5 times more bacteria than USC.)
FSC, HFC and USC protocols all show significant after-cleaning reductions in contamination compared to traditional methods, with labor savings. Other protocol data is being gathered.
Hand-held ATP meters enable on site results monitoring within minutes of completion of cleaning, and provide a more effective way to assess cleanliness than visual inspection; an important factor in sensitive environments such as schools and hospitals. Hospital Infection magazine (published by The Hospital Infection Society) stated in 2000:
“A four-part study assessing cleanliness on up to 113 environmental surfaces in an operating theatre and a hospital ward was reported. Surfaces were assessed visually, using microbiological methods and ATP bioluminescence … Using published microbiological and ATP specifications, 70 and 76% of … sites were unacceptable after cleaning. Visual assessment was a poor indicator of cleaning efficacy with only 18% considered unacceptable…”
Professor Mike Wren, biomedical scientist in clinical microbiology, University College London Hospital said: “Some of the most useful indicators of true cleanliness are ATP bioluminescence measurements…”
For the above reasons, ATP is a very promising marker for validating cleaning effectiveness. ATP devices are also becoming increasingly affordable, with costs for hand-held units and kits starting at less than $1,000.
Biodetectors
Biodetectors can detect specific germs, allergens and other organisms using ‘biological recognition’. These units range in size from desktop sized to hand-held, and use a variety of collection methods. The devices can use antibodies, living bacteria, single-celled organisms or tissues of higher organisms to detect the presence of unwanted substances based on a biological reaction. For example, if living cells inserted in the device react to certain antibodies, the biodetector can identify the specific bio-contaminant. Results can be delivered within 30-90 minutes.
Biodetectors developed to thwart bioterrorism may prove useful to the cleaning industry. These fall into three categories: those detecting a DNA sequence or protein that identifies the contaminant; living cells that react to specific agents and produce a measurable response; and mass spectrometry units that identify chemical components by molecular mass and cross-match them with biological agents of known molecular mass.
Portable DNA detection devices can now prepare and test samples within a very short time. The units basically break open bacterial spores and extract their DNA to identify the organism like a virtual "laboratory on a microchip". Procedures that used to take six hours in a lab can be done in the field in perhaps an hour or less. Northwestern University has developed a DNA-based biochip for identifying pathogenic microorganisms. Other units are being designed for anthrax identification.
The Autonomous Pathogen Detection System, or APDS, monitors the air like a smoke detector, and can detect and identify bacteria, viruses, and toxic substances. Costs and expertise required for most of these devices remain prohibitive for cleaning validation purposes (they were mainly designed for the military and medical sectors), but prices are expected to fall, and ease-of-use improve, as demand grows and biodetector technology advances.
Mold Detectors
Mold detectors are hand-held portable devices that detect fungal enzymes to determine total fungal biomass. Though the units cannot differentiate between types of mold, they can accurately determine on site within one hour the presence of fungi, and the effectiveness of mold remediation on surfaces including wood, grout, and various building materials.
“Our experience with [a mold detector] as the final clearance methodology for HVAC and mold remediation has been excellent… [it] documents the … efforts of our technicians,” said Tim Herbert, of Air Purification Specialists, Inc.
Mold detectors and test kits can be initially costly ($7,000+ each), but are especially useful for mold remediation verification, and can recoup costs over time (e.g., according to MycoMeter, a leading maker of mold detectors, 100 samples, charged at $75/sample, can generate fees sufficient to pay for the equipment purchase and kit supplies.)
Conclusion
According to Gene Cole: “Comparative research is necessary to identify optimum cleaning effectiveness measurement methods for specific target markers across different environments, materials and surfaces, and applications. Such research, conducted in a cooperative mode of effort, will serve to define the many aspects of ‘clean’, and help to establish consensus standards of care for ‘cleaning effectiveness’ within the industry.”
In short, science now provides us with technology-assisted ‘eyesight’ to detect generally invisible micro-soil, then remove it, and prove it. This helps us realize cleaning’s ultimate purpose and potential – to protect people from unseen environmental harm.
A 25-year veteran in the housekeeping and cleaning industry, Allen Rathey began his career by establishing a home and commercial cleaning service in the early 1980s. After 10 years of first-hand experience, he transitioned from cleaning to consulting, providing advice and marketing services through his communications company, now InstructionLink/JanTrain, Inc. (ILJT). ILJT helps a wide range of cleaning industry organizations from start-up businesses to Fortune 500 companies, develop credible marketing messages, medical and scientific advisory boards, scientific communications and related outreach. The goal? Refine and validate products and processes to produce better and healthier indoor environments, then effectively deliver best practice information to the public.
Rathey's passion for educating the marketplace about the life-enhancing, health and other benefits of effective cleaning and housekeeping, prompted him to start The Housekeeping Channel in 2004. The Housekeeping Channel provides consumers with better, faster and healthier housekeeping tips and in-depth information. The Housekeeping Channel's portfolio of best practice advice comes from a range of leading professionals, including cleaning experts, professional executive housekeepers and professional cleaning services, scientists and doctors, environmental specialists and organizational and time-management consultants. More than 50,000 unique visitors go to the Housekeeping Channel each month, many spending more than an hour per visit.
Rathey is also the president of The Healthy House Institute, an online resource for a better, safer indoor environments.
Allen has been tapped as a housekeeping expert by The New York Times, U.S. News and World Report, BrandWeek Magazine, Real Simple, WebMD, and other national media. He has written articles for more than two-dozen international trade and consumer magazines.
Popular Topics: MRSA | Staph | Norovirus | Flu | E. Coli | C. Difficile | Salmonella | Cleaning for Health | Nosocomial Infections | Disinfection | Bacteria | Viruses | Indoor Air Quality | Asthma | Allergies | Allergen | Mold
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Comment by Charles Gerba on March 28th, 2008 at 7:48am
The "Remove It and Prove It" article is a very good summary.
Chuck Gerba
Charles P. Gerba, Ph.D.
Professor of Environmental Microbiology,
Departments of Microbiology and Immunology,
and Soil, Water and Environmental Science,
University of Arizona
Comment by Jay Glasel on March 27th, 2008 at 6:38pm
An example of the first class of biodetectors mentioned above are ones that can detect specific bacteria, allergens (substances, usually proteins, that cause allergic reactions in humans) and even living organisms using ‘biological recognition’ by antibodies. The method depends on antibodies that recognize, and bind strongly and specifically to, substances on the surfaces of the biological samples to be detected. The antibodies are usually fixed to a surface within the detector. A sample containing suspected contaminants is washed over the fixed antibodies, and binding between an antibody and the specific substance it binds to is allowed to take place. The existence of the bound substances may then be determined by a number of different methods. Using arrays of different antibodies, each specific for a different species of bacteria or protein, can allow simultaneous detection of the components in mixtures of contaminants.
Jay Glasel
(Dr. Glasel is the Managing Member and Founder of Global Scientific Consulting, LLC. He is a Professor Emeritus in the Department of Microbial, Molecular and Structural Biology at the University of Connecticut.)
Comment by Jay Glasel on March 27th, 2008 at 6:31pm
ATP is an amazing substance - some scientists have called it the most important molecule in the biochemistry of life. Much of the energy contained in the food nutrients that all living things (including microbials and us) consume to stay alive is converted to ATP within the cells that make up each organism. The ATP is transported to all the places in the cell where energy is needed and the energy is liberated at those places by the conversion of ATP to an energy-depleted molecule. In a cyclical turnover process, these energy-depleted molecules return to sites within each cell where more nutrient molecules are used to produce more ATP for further use as energy. Processes such as photosynthesis in plants, brain activity and muscle contraction in humans, reproduction of bacteria, and respiration in fungi are examples of processes driven by ATP. Of special interest here, the light that fireflies produce in their tails as a mating signal is powered by the energy contained in ATP: The ATP energy is converted to light flashes in a special enzyme-catalyzed reaction.
The amount of ATP in a cell—whether it’s a single celled organism such as a microbe—or the cells in our bodies—is typically only sufficient to supply the cell’s energy needs for a few minutes (in the case of the human brain, only a few seconds) if its nutrient-requiring turnover is interrupted. The cyclical energy production of ATP is such that the cells in an average person at rest consume and regenerate a total amount of ATP at the rate of over 3 lbs per hour!
Along with living microbial cells, the cells in most undamaged vegetable and animal-derived foods continue to maintain some of their ATP. However, when any of these cells are damaged, the ATP contained within them can leak out and dry on surfaces. This ATP is chemically quite stable and can remain on surfaces unless rigorously removed by cleaning.
Scientists and engineers have learned how to use the firefly light-producing reaction to detect microbial contamination on surfaces indirectly by using the ATP contained in the microbial cells to produce light. For example, samples of surfaces may be obtained by swabbing a surface. Then any microbial cells in the sample can be chemically burst open (“lysed”) in the presence of the ingredients of the firefly reaction. A measurement of the intensity of the resulting quick flash of light by a photodetector can be used to estimate the number of microbials that were present in the sample. It is only an rough indirect estimate because microbial cells from different species have different amounts of ATP in them.
Indirect estimation of microbial contamination levels by ATP measurements using the firefly reaction can sometimes give inconsistent results, however. If undamaged animal or plant cells are taken up with the surface samples along with living microbial cells, the ATP within the animal and plant cells also makes a contribution to the burst of light and can cause an over-estimation of the actual microbial contamination. Also, if food or microbial cells on a surface have been damaged (for example, by disinfectants or mechanical disruption) they spill the ATP within them on the surface where it can dry. This ATP will be picked up when a surface sample is taken and also lead to an over-estimation of the live microbials on the surface. Wood surfaces, especially unfinished ones, are prone to this type of background contribution because the ATP from damaged or within dry dead cells can be deposited in the spaces between the wood fibers where ordinary cleaning doesn’t efficiently remove it.
A relatively simple method may be used to remove ATP backgrounds coming from ATP deposits on surfaces. An enzyme called “ATPase” that catalyzes the breakdown of ATP slowly may be applied to a part of the surface sample and allowed to eliminate all the non-cellular background ATP before bursting the intact cells in the sample and measuring the quick light flash. The intensity of this flash of light results from only the ATP within cells. Measuring the intensity of the light flash from the other part of the surface sample gives a measure of the total amount of ATP on the surface including that from both living and damaged cells.
Jay Glasel
(Dr. Glasel is the Managing Member and Founder of Global Scientific Consulting, LLC. He is a Professor Emeritus in the Department of Microbial, Molecular and Structural Biology at the University of Connecticut.)