Microbial Mechanisms Flashcards
Provide microorganisms with the capacity to avoid host defenses and damage host cells, tissues and organs in a number of ways
MICROBIAL VIRULENCE FACTORS
are virulence factors that allow bacteria to attach to host cells.
Adhesins
Adehesin
- Streptococcus mutans
Glycocalyx
Adhesin
- Streptococcus pyogenes
• M protein
Adhesin
- Neisseria gonorrhoeae
• Opa protein
Adhesin
- Treponema pallidum
• Tapered end
2 types of toxin
Endo
Exo
- are produced inside mostly gram positive bacteria as part of their growth and metabolism.
They are then secreted or released following lysis into the surrounding medium.
Exotoxin
- are part of the outer portion of the cell wall of gram negative bacteria. They are liberated when the bacteria die and the cell wall breaks apart.
Endotoxin
ENZYMES
• - coagulate blood
• - Digest fibrin clots
• - hydrolyses hyaluronic acid
• - hydrolyzes collagen
Coagulase
Kinase
Hyaluronidase
Collagenase
TOXINS
• - ability to produce toxins
• - presence of toxin in host’s blood
• - antibodies against a specific toxin
Toxigenicity
Toxemia
Antitoxin
Study of disease
Pathology
Study of the cause of disease
Etiology
Development of disease
Pathogenesis
Pathogenic colonization of the body
Infection
An abnormal state in w/c the body is not normally functioning
Disease
NORMAL MICROBIOTA
• Transient microbiota
• Normal microbiota
• Opportunistic microbiota
SYMBIOSIS
Both organism benefit
One organism benefits, and the other is unaffected
One organism benefits at the expense of the other
Mutualism
Commensalism
Parasitism
Pathogens limited to a small area of the body
Local infection
An infxn throughout the body
Systemic infx
Systemic infxn that began as a local infection
Focal infx
Bacteria in the blood
Bacteremia
Growth of bacteria in blood
Septicemia
Disease-causing microorganisms
Pathogens
shelters and supports the growth of pathogens
Host
Disease-causing microorganisms
pathogen
invasion or colonization of the body by pathogenic microorganisms
Infection
Change in the state of health; abnormal state in which a part or the whole body is not properly adjusted or nor functioning properly
Disease
• Science that studies when and where diseases occur and how they are transmitted in populations
Epidemiology
Acute infxn that causes the initial illness
Primary infx
Opportunistic infn after a primary infection
Secondary infx
No noticeable S/S symptoms (inapparent infection)
Subclinical disease
BENEFICIAL EFFECTS of the
NORMAL MICROBIOTA:
• prevent growth of pathogens by occupying niches that pathogens might occupy
• produce growth factors such as folic acid and vitamin K
• Probiotics
- microorganisms that establish permanent colonies inside or on the body without producing disease
Normal microbiota
- microbes that are present for various periods then disappear
Transient microbiota
