Bacteria are single celled organisms and as such do not have a nervous system to communicate messages to other bacteria.
Bacteria communicate by secreting their extracellular polymeric substances (EPS) also known as "slime" to facilitate communication via quorum sensing. Within this slime, bacteria can align their metabolism as a collective unit and share metabolic resources, shield themselves, and increase resistance to antimicrobials. Sometimes the biofilm layer can be quite thin, chemically hardened, and invisible to the naked eye.
Biofilms are most common in the presence of liquids and can be found in living tissue. One example of a biofilm is the plaque in your mouth. However, biofilms can also exist in the grain structure of metals, plastics and other non living materials. Biofilms can corrode their host. Portions of biofilms can detach from their original point of formation and move to new locations.
(Above) Atomic force microscopy image of a single bacterial cell and its associated EPS on a surface of AISI 316 stainless steel.
In commercial food production, biofilms can shield bacteria from chemicals and light physical contact. This includes culturing swabs and ATP lysing agents used in microbial detection. From a quality perspective, this can create false negatives in microbial testing of surfaces. Front line quality personnel may believe they are getting an intermittent signal from microbial testing, but what they might be measuring is a seemingly sanitary surface, yet beneath a biofilm are active pathogens. When these biofilm break away or are erroded, the "positive" signal returns, then disappears, reappears, ect.
Biofilms can resist chemical attack. Imagine wiping away on a surface with a bleach soaked cloth to no effect. This is what makes biofilms frustrating to those who do not realize they are dealing with a biofilm. It also supports the case for dry sanitizing where possible, but it is not always possible where moisture is neccessary for a process.
On large or difficult to reach surfaces, detection of biofilms can be achieved through optical methods, yet this is a new and specialized method that is best employed with professional assistance. Your United Sanitizing application specialist can help.
Eradication of biofilms requires an aggressive response, typically involving heating or polishing the grain structure where the bacteria are hiding. Some materials are more conducive to biofilm colonization than others and should be avoided if neccessary. Once the colony is suppressed, the focus is on eliminating root causes and using a more robust sanitizing strategy.
United Sanitizing helps clients improve brands through comprehensive sanitizing strategy. Your United Sanitizing application specialist is ready to address your specific needs and apply quality methodology and best practices of industry leaders. We listen, then deliver.