Formation of microbial biofilms preparing by: Assist. Lect. Aysar Ashour Khalaf There are many studies about bacterial and fungal biofilm which they were considered a very big problem now days ,because of that it was one of the most virulence factors which in turns increased resistant for antibiotics . Bacterial biofilms are complex surface attached communities of bacteria held together by self-produced polymer matrixs mainly composed of polysaccharides, secreted proteins, and extracellular DNAs Bacterial biofilms are complex surface attached communities of bacteria held together by self-produced polymer matrixs mainly composed of polysaccharides, secreted proteins, and extracellular DNAs A biofilm can consist of a single microbial species or a combination of different species of bacteria, protozoa, archaea, algae, filamentous fungi, and yeast that strongly attach to each other and to biotic or abiotic surfaces bacterial biofilm formation relies on the interaction between the bacterial cells, the substrates and the surrounding media . And the formation of bacterial biofilms is a multi-step process starting with reversible attachment to surfaces aided by intermolecular forces and hydrophobicity, and then progress to extracellular polymeric substances (EPS) production which enable the cells to permanently adhere to a surface there are five main phases involved in the biofilm formation process: reversible attachment irreversible attachment EPS production maturation of biofilm dispersal/detachment There are various methods to detect biofilm production like : The microtiter plate (also called 96-well plate) assay Tissue Culture Plate (TCP). Tube method (TM). Congo Red Agar method (CRA). bioluminescent assay. piezoelectric sensors. fluorescent microscopic examination.

1. preparing by:
Assist. Lect. Aysar Ashour Khalaf
Formation of microbial
biofilms

2. There are many studies about
bacterial and fungal biofilm
which they were considered a
very big problem now days
,because of that it was one of
the most virulence factors
which in turns increased
resistant for antibiotics .

3.  What is the Biofilm of microbes?
 A biofilm can consist of a single microbial species
or a combination of different species of bacteria,
protozoa, archaea, algae, filamentous fungi, and
yeast that strongly attach to each other and to
biotic or abiotic surfaces
 Bacterial biofilms are complex surface attached
communities of bacteria held together by self-
produced polymer matrixs mainly composed of
polysaccharides, secreted proteins, and
extracellular DNAs

4. bacterial biofilm formation relies on the interaction between the bacterial
cells, the substrates and the surrounding media . And the formation of
bacterial biofilms is a multi-step process starting with reversible
attachment to surfaces aided by intermolecular forces and hydrophobicity,
and then progress to extracellular polymeric substances (EPS) production
which enable the cells to permanently adhere to a surface.
 there are five main phases involved in the
biofilm formation process:
 reversible attachment
 irreversible attachment
 EPS production
 maturation of biofilm
 dispersal/detachment

7. PROPERTIES OF BIOFILMS:

8. PROPERTIES OF BIOFILMS:

9. Many the most important one is known as Quorum
sensing system and this system responsible of
regulating the density of bacterial cells in biofilm and
responsible of regulating the gene expression during
biofilm production operation
Factors influence the biofilm formation

10. Risks of Bacterial Biofilms
 Bacteria are able to colonize and form biofilms on virtually all kinds of
surfaces both natural and synthetic surfaces,
 Chronic and nosocomial disorders .
 Fouling of industrial tubing.
 Grain spoilage,
 marine and milk pollution and ship hull fouling,
 Healthcare Issues (Establish surfaces like catheters on surgical
devices,Heart pumps, rhyphemes, implants at the breast, contact
lenses.andCSF shunts .
 life-threatining and human diseases, such as CF, otitis medium,
periodontitis, bacterial endocarditis (IE), chronic disease and
osteomyelitis.
In plant, P. aeruginosa biofilm on the roots of Arabidopsis and Ocimum
Basilicum (sweet basil). Food safety and food industry Biofilms account for
nearly 60% of Outbreaks of foodstuffs Listeria monocytogenes, which can
induce abortions in pregnant women and other complications for
immunocompromised people, are the most common biofilm forming
foodborne pathogens and spoilage species.

12. Biofilm Formation inThe Lab.
There are various methods to detect biofilm production
like :
 The microtiter plate (also called 96-well plate) assay
 Tissue Culture Plate (TCP).
 Tube method (TM).
 Congo Red Agar method (CRA).
 bioluminescent assay.
 piezoelectric sensors.
 fluorescent microscopic examination.

13. A
B
C D
The Microtiter plate (also called 96-well plate) assay

14.  Tube method (TM).
 Congo Red Agar method (CRA).

15.  Congo Red Agar method (CRA).
 The effect of alcoholic extract of Punica granatum peels on the
gene expression of the gene ALS₁ of the yeast Candida albicans
which forming biofilm and isolated from mouth area
BHJB 37
Sucrose 50g
Agar – Agar 10g
DistilledWater 1000ml
8g of congo red stain in 100 ml of d.w.

17. The gene expression of the gene ALS₁ of the yeast
Candida albicans by RT-PCR