1. Physico-chemical resistance
As illustrated in Figure 1, the biofilm mucous matrix (extracellular polymeric substance) has several functions including:
- providing protection
- acting as a filter
- acting as an electrostatic barrier
- preventing the penetration of disinfectants into the centre of the biofilm
In addition, when in a biofilm, the bacteria activate genes which are responsible for the synthesis of specific proteins called "resistance proteins".
Bacteria deep inside the biofilm have a slower metabolism compared to those in the outer parts. They also have a less permeable membrane and are more difficult to access, making them more resistant to many disinfectants.
2. Extra-chromosomal resistance
Bacterial resistance to disinfectants is higher when bacteria are in suspension (planktonic bacteria). This is due to the acquisition of specific resistance genes carried by plasmids (circular periplasmic chromosomes). In a biofilm, the plasmids are transferable between bacteria in intercellular bridges (Figure 2). Thus, the acquired resistance can be quickly spread to all bacterial species via horizontal transfer.
Epidemiological consequences of biofilms
Numerous bacterial species and genera that cause infections in animals and which may or may not have zoonotic potential, can form biofilms. Some examples are:
- Salmonella
- Camplyobacter
- E. coli
- Pseudomonas
- Staphylococcus
- Streptococcus
In animal husbandry, contamination of surfaces, air conditioning and ventilation systems, and water distribution systems with biofilms is a huge problem. Biofilms harbour pathogenic microorganisms which contribute to the continuous spread of infections in animals. But several of these species also have an impact downstream in animal production and food industries, because of their ability to cause infections or food poisoning in humans.
Biofilms are therefore a constant threat to biosecurity because of their ability to diffuse into the environment and colonize all kinds of media. Their resistance to extreme conditions, including disinfection procedures in livestock houses only makes matters worse.
Solutions from Huvepharma
Biofilms increase bacterial resistance to antibiotics, disinfectants, and the immune response of the host. Huvepharma, through its expertise in the areas of biosecurity and animal health, provide a range of products to prevent biofilm development.
Before the disinfection step, it is imperative to carry out a cleaning step with a surfactant to dissolve and eliminate both the visible organic deposits and most of the protective matrix of the biofilm. Adherence to this procedure guarantees increased effectiveness of the disinfectant, decreasing contamination of the surfaces before placing a new flock or herd in the building.
For more information about our range of hygiene products, please contact [email protected].
