Virulence factors of Bacteria that
cause disease
Submitted By :
Nesren alkakhrass
Supervised By:
Dr. Abedelraouf A. Elmanama
Ph.sc Microbiology (
TheMechanisms of Bacterial
Pathogenecity
EXAMPLES OF SPECIFIC ATTACHMENTS OF
BACTERIA TO HOST CELL OR TISSUE SURFACES
Bacterium
Streptococcus
pyogenes
Enterotoxigen
ic E. coli
Adhesin
Receptor
Attachment
Disease
site
Protein F
Amino
terminus of
fibronectin
Pharyngeal Sore throat
epithelium
Type-1 SpeciesIntestinal
fimbriae specific
epithelium
carbohydra
Diarrhea
te
Bordetella
pertussis
Fimbriae
Galactose
Respirator
("filament on sulfated y
ous
glycolipids epithelium
hemaggluti
nin
Whooping
cough
M PROTEIN STRUCTURE
SOME EXTRACELLULAR BACTERIAL PROTEINS THAT
ARE CONSIDERED INVASINS
Invasin
Bacteria
Involved
Activity
Hyaluronidase Streptococci, Degrades hyaluronic of
staphylococci connective tissue
and clostridia
Collagenase
Clostridium
species
Neuraminidas Vibrio
e cholerae and
Shigella
dysenteriae
Dissolves collagen
framework of muscles
Degrades neuraminic acid
of intestinal mucosa
Salmonella
(
Cell invasion by GFP-expressing
Salmonella-induced actin rearrangement
Apoptosis as Bacterial virulense factor
programmed cell death: activation of
apoptosis to destroy cells,
utilization of apoptosis to initiate
inflammation
• The induction of apoptosis by Bordetella
pertussis adenylate cyclase hemolysin
•P. aeruginosa can induce apoptosis by producing
exotoxin
Quorum Sensing as a virulence
factor

An important factor in the pathogenesis of some
infections is a bacterial cell-to-cell signaling
mechanism, referred to as "quorum sensing",
which enables bacteria to coordinately turn on
and off specific virulence genes through the
production of autoinducer molecules.
•Interference or blocking of quorum-sensing
systems lead to inhibition of a variety of virulence
factors.
Genomics and Bacterial Pathogenesis

Complete knowledge of an organism's genetic
makeup allows exhaustive identification for
virulence genes, vaccine and antimicrobial
targets, and diagnostics.

The genomes of at least 13 pathogenic bacteria
have been sequenced
Strategies To Block Bacterial Adhesion
used as new treatment