Introduction Flashcards
What is a pathogen?
A microbe that causes disease in normal healthy humans
Who was Edward Jenner?
Cow-pox vaccine guy (vacca = cow)
Who was John Snow?
The guy with the well in London
Pasteur findings:
1) Microbes cause fermentation
2) Microbes does not spontaneously show up
Kochs postulates:
Overall - when can you say that a pathogen causes a disease
1) The organism is present always when there is disease
2) It can be isolated in cultivated in vitro
3) Inoculation of culture should cause disease
4) The organism can be reisolated from new host.
aseptic
seperation of steriale materials from materials with microbes.
Alexander flemming:
Discoverer of penicilin.
Obligate parasite
A parasite that depends on humans
Obligate pathogens
A pathogen that need to cause disease to spread
Fomite
Inanimate object that can transmit infection
Exogenous infection
One that arrives from a microorganism not already present in us
Prevalence
Total number of cases in a predefined population at particular time
Incidence
New number of cases within a time period
Carl Woese
sRNA opdager
LUCA
Last Universal common ancestor
The two basic bacterial shapes:
1) Spherical (cocci)
2) Rod (bacillus)
Subdivision of Bacillus
1) Vibrio (comma shaped)
2) Spirillum (spiral shaped)
3) Actinomyces (filamentious)
What is an inclusion body?
E.g. a spore - a big cytoplasmic structure used for storage of some kind.
Ribosomes in bacteria
70 S (30 and 50 S)
Ribosomes in eukaryotes
80 S (40 and 60 S)
Where is LPS found
Mostly in the outer membrane of gram negative bacteria
What is endotoxin?
LPS especcially the lipid center of LPS creates inflammatory response
3 extracellular polysaccharide structures:
1) capsule (can be seen in microscope)
2) microcapsule (cannot be seen but can be found using serological tests)
3) Loose slime (not as closely associatedd with the bacterial envelope)
Interacts swith external environment (e.g. anti phago, extreme conditions)
Genera that form spores
1) Bacillus
2) Clostridium
Germination
Reactivation of spores
Difference between exo and endospores
Where they are produced and carried by the organism
Virion
Basic infectious particle of the virus
Capsid
Protein surrounding genetic material virus (can have host-drevied plasma membrane envelope)
Cladistic
An evolutionary way of looking at bacterial classification
Phenetic
A phenotypic way of looking at bacterial classification
Name the 4 classical DNA based classification tools:
1) DNA composition (GC)
2) DNA homology (hybridisation)
3) 16s Sequencing
4) WGS
Name the 6 important phylums of bacteria mentioned in the book
1) Actinobacteria (Gram+)
2) Firmicutes (gram+ coccus)
3) Proteobacteria (bram- both coccus and bacillus)
4) Bacteroidetes (gram-)
5) Spirochaetes (gram-)
6) Chlamydiae
Name the most important ways of identifying bacteria
1) Microscopy
2) cultural characteristics
3) Biochemical reactions
4) MALDI-TOF MS
5) Nucleotide based
6) Antigenic characterisation
Panmitic
When are specific species undergoes a lot of genome changes so colonies are very diverse
clonal
Opposite of panmitic
A strain
A population of bacteria assumed to arrive from the same bacteria
An isolate
A sample of primary culture
typing
Figuring out which strain of bacteria there is in an isolate
PAMP
Pathogen associated molecular pattern
Lyzosym
Protein that degrades peptidoglycan - part of innate immune system - in macrophages, neutrophils and fluids.
Acute phase proteins
Proteins that are measured upon infection - e.g. c-reactive protein that binds phosphocholin in some bacterial membranes.
Types of baccterial pathogens
1) Opportunustic
2) Primary (causes disease in helthy intact patients)
3) Zoonoses
Virulence determinants
The proteins that a pathogen has that causes its mode of action.
Name the most common modes of adhesion (in context of pathogenic invasion)
1) Adhesion by fimbrial adhesion (through the fimbria)
2) non-fimbrial adhesion (Usually protein, polysaccharide on surface or excreted)
3) binding to connective tissue proteins
Invasion
Some pathogens need to invade the cells in the body. This is done by passing the plasma membrane - usually through receptor contact.
Mention the most important staging in pathogenic infection:
1) Colonisation (e.g. adhesion)
2) Invasion
3) Survival and multiplication
4) Avoidance of host defence
