Name 3 of the 6 major contributors to microbiology introduced to you in lecture 1
Robert Hooke, Antoni Van Leeuwenhoek, Ignaz Semmelweis, Loius Pasteur, Joseph Lister or Robert Koch
100
What is the difference between a mixed and pure culture and which one do we want to achieve?
MIXED CULTURE: many different bacterial species are growing in/on the media
PURE CULTURE: only one species is growing in/on the media
WE WANT PURE CULTURE ie we want to isolate ONLY our bacteria of interest
100
What is a virulence factor
Traits/Structures that collectively give the microbe the ability to cause disease
100
What is the difference between 'obligate' and 'facultative'?
Obligate: MUST have
Facultative: with or without
200
What do Koch's Postulates describe?
The Germ Theory of Disease
200
How do we achieve single colonies?
Streaking out... a dilution process
200
Dental plaque is an example of a....
Bacterial Bioilm
200
What are the growth conditions of a mesophile and why are they clinically relevant for humans?
Growth 10 to 45ºC, optimum = 37ºC
37ºC ... the temperature of the human body!!
300
Who was the first person to introduce hand washing or 'antisepsis' into clinical practice?
Ignaz Semmelweis
300
GENERALLY when temperature for what time do we incubate our agar plates to grow bacteria?
Plates incubated at 35-37°C for 18-24 hrs
300
What are the 2 types of bacterial toxins and what is the difference?
Endotoxins: released upon cell death as cell disintergrates ie is a structural component of the cell (LPS in cell wall of gNeg)
Exotoxins: is produced and secreted by a living bacterial cell ie an exoenzyme (mostly gPos)
Abiogenesis: the theory of spontaneous generation
... we now know that matter (or more correctly mass) cannot be created or destroyed, only transferred from one state to another (The Law of Conservation)
400
What is the difference between SELECTIVE and DIFFERENTIAL media?
SELECTIVE MEDIA only allow certain bacteria to grow while inhibiting others (ie you can use it to isolate a specific bacteria by using it's growth requirements ie fungi on SAB)
DIFFERENTIAL MEDIA contain substances that will allow different bacteria to be distinguished (ie it will behave in a certain way when certain bacteria are grown on it ie heamolysis on blood agar)
400
Name and describe the 3 types of haemolysins
Alpha - partial lysis of RBC - green/grey zone
Beta - completely clear zone around colonies
Gamma- Non-haemolytic
400
What are the 3 categories relating to pH?
Acidophiles– prefer acidic pH , optimum pH 0 - 5.5
Alkalophiles– prefer basic pH, range pH 8.5 - 11.5
Neutrophiles– prefer close to neutral pH, optimum pH 7.2 - 7.6