CMB1003/L08 Infectious Disease Flashcards
How do pathogenic microbes cause disease?
Gaining a foothold in a particular niche
Which part of the respiratory tract is typically devoid of microbes?
Lower respiratory tract
Give 2 mechanisms by which Mycobacterium tuberculosis becomes drug resistant.
Cell wall structure and efflux
How is Mycobacterium tuberculosis transmitted?
Respiratory expulsion
How does Legionella pneumophila survive inside immune cells?
Generates a protective vacuole
Why is Legionella pneumophila described as an amino acid auxotroph?
Promotes proteasomal degradation to gain nutrients
Give 3 causes and infectious characteristics of gastroenteritis.
Bacterial - ingestion, faecal-oral, contamination
Viral - vomiting bugs
Parasitic - water-bourne
What is the difference between InPEC and ExPEC E. coli?
Intestinal vs extraintestinal
What is the most common serotype of E. coli?
O157:H7
Associated with beef and leafy greens
What are the effects of the Shiga Toxin encoded by E. coli?
Causes HUS
What is the result of phage-encoded CTX produced by Vibrio cholerae?
Massive fluid loss
Give 2 examples of pathogens that can cause UTIs.
E. coli
P. mirabilis
P. aeruginosa
K. pneumoniae
C. freundii
A. baumanii
Define ‘opportunistic pathogen’.
An organism that causes disease in the absence of normal host resistance
Define inflammation.
A nonspecific reaction driven by neutrophil accumulation
Define bacteraemia.
Presence of bacteria in the bloodstream
Define sepsis.
Extreme, system-wide inflammatory response to blood poisoning
Define systemic shock.
Systemic drop in blood pressure leading to mass organ failure
What kind of E. coli lives harmlessly in the gut?
UPEC
How does enrichment media differ from general media? (2)
Supplement media with sheep’s blood
For fastidious bacteria
Describe selective media.
Represses growth of unwanted pathogens
Describe differential media.
General purpose with chromogenic substrate additives
Tests for presence/absence of enzymes for diagnosis
Describe selective/differential media. (3)
Contains bile salts and crystal violet that inhibits Gram +ve bacteria
pH indicators allow fermentation of sugars to be monitored
Contains lactose
