This site is 100% ad supported. Please add an exception to adblock for this site.

Microbiology Lab

Terms

undefined, object
copy deck
What do Gram Positive cocci produce?
Endotoxins called hemolysins
Hemolysins are capable of what?
Destroying red blood cells and hemoglobins
What are three major types of Hemolysins?
Beta, Alpha and Y
What do Beta Hemolysins do?
Complete destruction of RBCs and hemoglobin. It results in a clearing of the medium around the colonies
What do Alpha Hemolysins do?
Partial destruction of RBCs and produces a greenish discoloration of the AGAR around the colonies
What do Y- Hemolysins do?
It is non hemolysis and appears as a simple growth with no change in the medium
The hemolysins produced by streptococci are called what?
Streptolysins
What are the two forms of streptolysins?
Streptolysin O and Streptolysin S
What is blood Agar especially useful for?
Detecting Hemolytic ability of Gram Positive Cocci and as a general purpse growth medium appropriate for fastidious and nonfastidious microogranisms alike
Describe the Streptolysin O
IT is oxygen-labile and expresses maximal activity under anaerobic conditions
Describe the Streptolysin S
It is oxygen-stable but expresses itself optimally under anaerobic conditions as well
How do you innoculate blood agar to make it favorable for streptolysins?
Streak-stab technique
How do the stabs encourage streptolysin activity?
because of the reduced oxygen concentraion of the subsurface environment
Why is snyder test medium formulated?
To favor the growth of oral bacteria and discourage the growth of other bacteria
What is Epidemiology?
the study of the causes, occurence, transmission, distribution, and prevention of diseases in a population
The snyder test is designed to meaure susceptibility to what?
Dental Caries
What is Dental Caries primarily caused by?
Lactobacilli and streptococci
Name three ways infectious diseases are transmitted
inhalation, direct skin contact, blood to blood contact
What is Common Source epdiemic?
When a disease is transmitted from an area such as a heating or cooling system of a building or contaminated water it infects many people all at once.
What is propagated transmission
a disease transmitted from person to person
The first case of such a disease is called te ____ ____
Index Case
How do you calcuate incidence rate
Number of new cases in a time period over size of at risk population at midpoint of time period X K
How is point Prevalence calculated?
Number of existing cases at a point in time over the total population X K
A
A

Deck Info

24

rhbronkhorst

permalink