Biofilm formation

1.  Source https://www.immunology.org/public-information/bitesized-immunology/pathogens-and-
disease/biofilms-and-their-role-in

2.  Bacterial association in biofilm is one way
found to protect themselves from the hostile
environmental conditions and promote
symbiotic relations.
Source https://ib.bioninja.com.au/options/untitled/b3-
environmental-protection/biofilms.html

3.  Stainless steel, especially on abraded or
scratched surfaces, to polypropylene.
 Biofilms may form in hard-to-reach areas,
such as the undersides of conveyor belts and
seals.
 For this reason, it is necessary to regularly
inspect and change equipment parts such as
gaskets, O-rings and piping.

4.  Extended production (longer runs)
 The lack of stringent cleaning regimes
 pH extremes and high contact-surface
 Temperatures that denature proteins,
facilitating the formation of a conditioning
layer
 A low fluid flow rate and nutrient availability.
 Dairy industry problem is very common

5.  Biofilm formation depends on an interaction
between three main components:
 The bacterial cells
 The attachment surface
 The surrounding
source : https://cmjournal.biomedcentral.com/articles/10.1186/s13020-019-0232-2

6.  The formation of biofilms typically involves
four steps:
 Biofilms are the product of a microbial
developmental process. The process is
summarized by five major stages of biofilm
development.
 Initial attachment
 Irreversible attachment
 Maturation I
 Maturation II
 Dispersion

7.  As the colony continues to attach, there is
production of extracellular
 Polysaccharides and changes in cell morphology.
Extracellular polysaccharide formation aids
adhesion of the cells in the film and protects the
bacterial layer against cleaners and sanitizers.
The polysaccharide will also trap other cells and
debris.
 The extracellular polysaccharide material forms
a bridge between bacteria and the conditioning
layer with a combination of electrostatic and
covalent bonds.
 Development and growth, without removal
intervention, results in the

8.  Film becoming irreversibly attached to a
substratum, interface or to each other,
embedded in a matrix of extracellular substance
that they have produced.
 Mature film reaches an equilibrium that delivers
oxygen, food and nutrients while carrying away
fermentation products and sloughed cells.
 The outermost slime layer of film serves as a
snare that traps additional contaminants and
acts as a protectant, sealing the bacteria within
so that the protected bacteria can be up to 100
times more resistant to sanitizer.

10.  Properties
 Biofilms are usually found on solid substrates submerged in or
exposed to an aqueous solution, although they can form as
floating mats on liquid surfaces and also on the surface of
leaves, particularly in high humidity climates.
 Given sufficient resources for growth, a biofilm will quickly
grow to be macroscopic (visible to the naked eye).
 Biofilms can contain many different types of microorganism,
e.g. bacteria, archaea, protozoa, fungi and algae; each group
performs specialized metabolic functions.
 However, some organisms will form single-species films under
certain conditions. The social structure
(cooperation/competition) within a biofilm depends highly on
the different species present

11.  In produce, microorganisms attach to the
surfaces and biofilms develop internally.
During the washing process, biofilms resist
sanitization and allow bacteria to spread
across the produce. This problem is also
found in ready-to-eat foods, because the
foods go through limited cleaning procedures
before consumption Due to the perishability
of dairy products and limitations in cleaning
procedures, resulting in the buildup of
bacteria, dairy is susceptible to biofilm
formation and contamination.

12.  One bacteria that can be found in various
industries and is a major cause of food borne
disease is Salmonella Large amounts of
salmonella contamination can be found in
the poultry processing industry as about 50%
of salmonella strains can produce biofilms on
poultry farms. Salmonella increases the risk
of foodborne illnesses when the poultry
products are not cleaned and cooked
correctly.

13.  Salmonella spp is also found in the seafood
industry where biofilms form from seafood
borne pathogens on the seafood itself as well
as in water. Shrimp products are commonly
affected by salmonella because of unhygienic
processing and handling techniques The
preparation practices of shrimp and other
seafood products can allow for bacteria
buildup on the products.

14.  1)The buildup of biofilms can affect the heat
flow across a surface and increase surface
corrosion and frictional resistance of fluids.
These can lead to a loss of energy in a
system and overall loss of products
 2)Economic loss.
 3)Health Risk: from 1996 to 2010 the Center
for Disease Control and Prevention
estimated 48 million foodborne illnesses per
year. Biofilms have been connected to about
80% of bacterial infections in the United
States.

15.  Example: Rapid surface adhesion capacity,
combined with biotransfer potential
throughout the stages of biofilm formation,
make L. monocytogenes a potential risk to the
food industry. Once present in the raw
material, L.monocytogenes will adhere rapidly
to the surface of stainless steel equipmentand
utensils, being able to multiply, forming
mature biofilms quickly. Biotransfer potential
combined with survival and multiplication
capacity in different substrates will cause this
bacterium to rapidly reach infecting doses.

20.  Chemical methods:
 A wide range of chemical disinfectants is available
and can be broadly divided into three groups:
 1. Oxidizing agents (chlorine-based compounds,
hydrogen peroxide, ozone, etc.).
 2. Surface-active compounds (including quaternary
ammonium compounds and acid anionic compounds).
 3. Iodophores.The efficacy of these is influenced by
pH, temperature of the contact surface,
concentrations of cleaning and sanitizing agents,
contact time, etc.
 Disinfectants are less effective around food residues

21.  Physical methods.:
 Ionizing radiation, atmospheric plasma
inactivation, ultrasound, electric fields, etc.,
have been developed and studied as
alternatives for chemical disinfectants used
in the food industries.
 These techniques appear to be effective
against biofilms and on microorganisms.
However, the applicability of these
techniques should be examined with
consideration of their cost and regulatory
aspects

22.  Dry clean:scraping, brushing, vacuuming,
sweeping or shoveling to remove large
particles.
 Potable rinse. :120-130-O c
 Apply detergent:chlorinated
detergent+oxidative detergent
 Final warm water rinse. :140o c
 Sanitize.

23.  ARS has already determined that a strong
negative electrostatic charge to biofilms on
stainless steel may reduce bacterial surface
contamination.
 strains of lactic acid bacteria can inhibit
growth of Listeria in a biofilm over extended
time. The lactic acid bacteria did not grow at
39 ºF but did produce an anti- Listerial
metabolite to keep levels of Listeria low

24.  1)Facility and equipment should be
hygienically designed so bacteria cannot find
harborage sites that protect them from
cleaning and disinfection.
 2) Additionally, the removal of biofilms is
greatly affected by the application of
mechanical force, such as brushing and
scrubbing, to the surface during cleaning.

25.  Hurdle technology: the combination of
sodium hypochlorite (NaClO) with UV
irradiation, NaClO with hydrogen peroxide
(H2O2), and ultrasound with enzyme had
better results than a single treatment.
 Development and plan cleaning and
disinfection programmes

26.  The hygienic design of equipment and
utensils.
 Identify biofilm-prone areas in existing
process lines and systematically monitor
organic and microbial load in these areas.
 Invest in research on the efficacy of cleaning
agents and disinfectants