Microbes 1 and 2 Flashcards
(32 cards)
Lipopolysaccharide is found on the outer membrane of the cell wall in a gram ___ bacteria, which causes:
gram negative bacteria, causes a strong inflammatory response. IL-1, TNF, NO induction, causes fever and hypotension.
Complement causes neutrophil recruitment, hypotension.
TF –> coagulation cascade.
if stains red, it is gram ____ and has ____.
if stains purple, it is gram ____ and has ____ acids
red= negative = Lipopolysaccharide purple = positive = peptidoglycan and lipoteichoic acid
gram positive cocci in a clump or cluster
staphyloCOCCUS aureus
gram positive cocci in pairs and chains
streptoCOCCUS– S. pneumonia, s..pyogenes, enterococcus
gram positive bacilli that forms SPORES
clostridium, bacillus
gram positive bacilli that DO NOT form spores
listeria
corynebacterium
T/F CDif produces spores
true. it is a gram positive bacilli.
Gram negative cocci/diplococci
neisseria (N. gonorrhoea, N. meningitides)
Gram negative bacilli
E. coli/eterobacteriales. salmonella, shigella, yersinia.
pseudomonas aeruginosa bacteria fragilis (normal gut flora)
CURVED gram NEGATIVE bacilli
campylobacter
h. pylori
vibriocholeae
species that poorly gram stain
mycobacterium
spirochetes (syphilis, Lyme disease)
All Bacilli are Gram negative except the gram positive ones (ABCDLMNOP)
Actinomyces Bacillus Clostridium (spores, gram positive) Diptheria/Corynebacterium Listeria (no spores, but gram positive) Mycobacterium (no stain) Nocardia Oh no, what's the last one Propionibacterium
All cocci are gram positive except the gram negative ones NMV
Neisseria
Moaxellla
Veillonella
is clostridium anaerobic
yes
primary pathogen
one that regular causes disease even in an INTACT immune defence system.
commensal pathogen
organisms that are part of the normal human flora or environment that do not usually cause infection
opportunistic pathogen
organisms that have the ability to cause an infection when the immune defences are impaired.
superantigen
Non-specific stimulation of T cells uncontrolled cytokine release (IL- 1, TNF)
i.e. Toxic Shock Syndromes of Group A Streptococcus, S.aureus
type of exotoxin
ways of overtly overcoming our immune system
-overwhelmign it through toxin and enzymes, T cell infection
ways of covertly overcoming our immune system
- immune modulation
- capsules: some pathogens have such a large capsule its hard to eat them. Disables phagocytosis.
- biofilm production
- antigenic variation: modifying their antigens so immune system cannot recognize them. or like mimicry (ex/ schistosome H. Adult worm in the host venous system coats itself wit host antigens to evade the immune response)
what type of bacteria takes the longest to culture
mycobacteria. (10d-7weeks).
most gram positive and negative bacteria takes 18-48 hours to culture
what is susceptibility testing
determines whether a pathogen is susceptible or resistant to a panel of antibiotics
minimum inhibitory concentration
minimum concentration of an antibiotic required to inhibit microbial growth
MIC ≤ 0.06 ug/ml are sensitive MIC = 0.12-0.5 ug/ml is intermediate MIC ≥ 1 ug/ml are resistant
differences between IgM, IgG.
What is window period and seroconversion?
IgM: usually indicates an acute infection
IgG: indicates a past infection or immunity.
Window Period: patient is infected, but antibody levels not developed to levels detectable.
Seroconversion: patient’s serology changes from negative to positive.
