Biofilms: A Common Enemy To Public Health Medication

BIOFILM is a community of cells irreversibly attached to either a biotic or abiotic surface embedded in a self-produced exopolymeric substance (EPS).
The formation of biofilm begins when free-living (planktonic) bacteria first reversibly attach and then irreversibly attached to a surface, divide, and recruit additional planktonic cells that are attached to the cells already on the surface, which gives rise to a biofilm. The emerging biofilm can be a single species bacterium or a combination of composed of different species. Single species bacterium is rarely found in a natural environment. More frequently, biofilms are composed of different species of bacteria, yeast, fungi, algae, and protozoa. They anchor themselves more permanently using cell adhesion structures such as pili, fimbriae,cillia, and flagella. Bacterial biofilm may contain spoilage bacteria such as Pseudomonas and Enterocccus spp. as well as pathogens such as Listeria moncytogenes, Staphylococcus aureus, and Escherichia coli 0157:H7 or Salmonella.
Any surface that contains abundance of moisture and nutrients is susceptible to biofilm formation if microorganisms are present. A wide variety of surfaces including living tissues, indwelling medical devices, industrial or potable water system piping and natural aquatic systems support biofilm formation. Biofilm formation is a survival strategy microbe adopt to enable them survive unpredictable environmental conditions such as temperature change, desiccation, ultralviolet radiation, cleansing agents such as biocides and disinfectant, and pressure. Biofilms are present almost everywhere and impact all aspects of our lives. In many cases their presence leads to prosthesis colonization, product contamination, biofouling, and equipment damage. According to the National Institutes of Health (NIH) and the Center for Disease Control (CDC) 90% of infections in humans and 65% of nosocomial infections are caused by biofilms. Biofilms are responsible for plaque formation on teeth, gum disease, ear infection in children, fibrosis, legionnaire disease, among others. Biofilms contaminate many household surfaces such as toilets, sinks, and cutting boards. In industrial settings, biofilms adversely impacts many processes leading to a decrease in process efficiency and end-product purity. Biofilms also contaminate water source and cause pipe plugging e.g. Helicobacter pylori, an organism responsible for gastric ulcer, has been found in drinking water systems.
Biofilms implication on public health
Biofilms have been implicated in different nosocomial infections associated with medical devices, hospital equipment, and other hard surfaces. It has been estimated that biofilms are associated with 65 percent of nosocomial infections.
In addition, fruits and vegetables, household and workplaces surfaces such as sinks,countertops, toilets, cutting boards and water pipes can all act as vehicles for the transfer of biofilm-associated infections to man.
Food borne biofilms and food safety
Generally, food has been identified to be a very efficient vehicle which brings a large number of people into contact with a potential hazard. Food-borne exposure may be the most critical pathway for transfer of biofilm-associated infections to humans. Fruits and vegetables are particularly noted in this regard as high risk because most of them are eaten raw or minimally processed.
Multispecies biofilms including human pathogens attach to plant surfaces from the soil and environment before harvest. This biofilm form on plant tissue so firmly that they are not easily removed with simple washing techniques. Consumption of fresh fruits and vegetables or when partially processed could be responsible for food-borne illness.
Cantaloupe melons are excellent source of beta carotene and vitamin A and B, but on many occasions, melons contaminated with Salmonella enterica has been medically linked with Salmonellosis outbreaks. Symptoms include abdominal cramping, diarrhea and fever. Although, most victim recover without treatment. Infection usually last for 4-7 days.
Apple juice or apple cider contaminated with E. coli0157:H7 during industrial process or harvest has been associated with Escherichia coli infections. Symptoms are usually mild and frequently involve severe stomach cramp, diarrhea, and vomiting. Some victims suffer more severe complications.
Many individuals rely on consumption of fresh salad for slimmer physiques. Pre-packaged salads and minimally processed leafy greens may be important for a reduced calorie (fat).
Recently, they have also been the most frequent source of food-borne illness. The U.S. Food and Drug Administration have linked 18 outbreaks of E. coli 0157:H7 to lettuce and one to spinach, basil, cabbage, green onions and parsley are also responsible for recent occurrences of food borne illness.
Biofilms and medical device-associated infections
Microorganisms commonly attach to indwelling medical devices e.g., urinary catheter, central venous catheter, medical heart valve etc and form biofilms. Scanning of medical device and transmission electron microscopy has shown that virtually all indwelling central venous catheters are colonized by microorganisms embedded in a biofilm matrix. These organisms may be acquired from the skin of patient or health care workers, tap water to which ports of devices are exposed, or other sources in the environment. Colonization of these devices can occur within 24 hours and may be a function of the host conditioning films e.g. lipid, protein, plasma etc. As a result of biofilm formation, 10 to 50% of patients undergoing short-term urinary catheterization (7 days) and patients undergoing long-term catheterization (less than 28 days) become infected. The types of organisms that develop biofilms are quite broad and a number of pathogenic bacteria and fungi.
Biofilm poses a serious problem for public health because of the increased resistance of biofilm associated organisms to antimicrobial agents and the ability for these organisms to cause infections in patients with indwelling medical devices. Naturally, microorganisms exist primarily by attaching themselves to and growing on living and non-living surfaces. These surfaces include those found in soil and aquatic system, those on the spectrum of indwelling medical devices, and those on living tissues such as tooth enamel, heart valve or lung, and middle ear.
The common feature of this attached growth is that the cells develop a biofilm. Biofilm have a great significant on public health, because biofilm-associated microorganism’s exhibit decreased susceptibility to antimicrobial agents. This susceptibility may be intrinsic (as a natural outcome of growth in the biofilm) or acquired (due to transfer of extrachromosomal elements to susceptible organisms in the biofilm).
Prevention and control
Toothpaste with antibacterial ingredient such as triclosan and mouthwash with chlorhexidine or mixture of essential oils in alcohol are effective in reducing dental plaque and gingivitis.
Effective cleaning of potential growth site, equipment design, temperature control, and reduction of nutrient and water are essential for biofilm control in the food industry.
Disinfectants such as chlorine, chloramines, and ozones are commonly used for treating biofilm forming microbes in water.
The use of sanitizer and detergent such as quaternary ammonium compound, acid-based sanitizer and hydrogen peroxide are effective against wild arrays of microorganisms.