stuff from saskias Flashcards
fluorescence dilution
tracks non-replicating persisters
fluorescence dilution
tracks non-replicating persisters
lack of FD (fluorescence stays same) shows…
lack of replication of cells
persisters are produced by a …….. process
stochastic
persisters do not grow in the presence of …..
antibiotics
persisters are …….
genetically identical
phenotypic variants
antitoxins
unstable
degrade to liberate the toxin (toxin action can causes cell arrest)
HicA and HicB
HicA causes growth arrest in E.Coli
HicB restores growth
single-cell analysis
microscopy
flow cell & cytometry
microfluids
treating persisters
reduce concentration of antibiotics
turbidity
optical density of a fluid (cloudiness)
temperature dry weight is achieved at
100-108 degrees
dry weight is ……… of wet weight
20-30%
counter stains
produce contrasting background
e.g. safranin
immersion oil
increases resolving power
fermentation of sugars
lactic acid production
allows measure of pH change
Ampicillin
B-lactam
Kanamycin
aminoglycoside
heterofermentative
produces lactic acid and sugar (mannitol)
buffers maintain…
pH
osmolarity
MRS agar
favours growth of lactobacilli
Bromocresol is yellow at…
bromocresol is …… at >pH6.8
purple
how is MIC measured
broth dilution method
higher turbidity
more resistance
more bacteria/growth
ribose sugar is found in..
RNA
bacteriolytic
destruction of bacteria by antibiotic
macrolide binding site
large ribosomal subunit
upper part of nascent peptide exit tunnel
fluoroquinolones target
DNA gyrase
fluoroquinolones enter bacteria by…
diffusion into gram +ve bacteria
via outer membrane prions - gram -ve
fluoroquinolones are…
bacteriocidal
synthetic
cephalosporins are….
broad-spectrum semi-synthetic beta-lactam derived from mould cephalosporium similar to penicillins
cephalosporins interfere with…
bacterial cell wall synthesis
antivirulence strategies offer….
a reduced selection pressure for drug resistant mutations
UPEC
uropathogenic E.Coli
exfoliation of cells (UPEC)
clears infection and promotes dissemination
lack of FD (fluorescence stays same) shows…
lack of replication of cells
persisters are produced by a …….. process
stochastic
persisters do not grow in the presence of …..
antibiotics
persisters are …….
genetically identical
phenotypic variants
antitoxins
unstable
degrade to liberate the toxin (toxin action can causes cell arrest)
HicA and HicB
HicA causes growth arrest in E.Coli
HicB restores growth
single-cell analysis
microscopy
flow cell & cytometry
microfluids
treating persisters
reduce concentration of antibiotics
turbidity
optical density of a fluid (cloudiness)
temperature dry weight is achieved at
100-108 degrees
dry weight is ……… of wet weight
20-30%
counter stains
produce contrasting background
e.g. safranin
immersion oil
increases resolving power
fermentation of sugars
lactic acid production
allows measure of pH change
Ampicillin
B-lactam
Kanamycin
aminoglycoside
heterofermentative
produces lactic acid and sugar (mannitol)
buffers maintain…
pH
osmolarity
MRS agar
favours growth of lactobacilli
Bromocresol is yellow at…
less than pH5.2
bromocresol is …… at >pH6.8
purple
how is MIC measured
broth dilution method
higher turbidity
more resistance
more bacteria/growth
ribose sugar is found in..
RNA
bacteriolytic
destruction of bacteria by antibiotic
macrolide binding site
large ribosomal subunit
upper part of nascent peptide exit tunnel
fluoroquinolones target
DNA gyrase
fluoroquinolones enter bacteria by…
diffusion into gram +ve bacteria
via outer membrane prions - gram -ve
fluoroquinolones are…
bacteriocidal
synthetic
cephalosporins are….
broad-spectrum semi-synthetic beta-lactam derived from mould cephalosporium similar to penicillins
cephalosporins interfere with…
bacterial cell wall synthesis
antivirulence strategies offer….
a reduced selection pressure for drug resistant mutations
UPEC
uropathogenic E.Coli
exfoliation of cells (UPEC)
clears infection and promotes dissemination
T3SS and T6SS
inject proteins
manipulate actin cytoskeleton
genes in faecal extract inhibit
salmonella growth
synergistic drugs suppress…
susceptible populations more than single drug therapies do
stages of phage infection
1 - adsorption to receptor 2 - DNA injection (peptidoglycan degradation and pore formation) 3 - assembly of phage particles 4 - bacterial cell lysis 5 - virions released
increase in MIC =
resistance
if MIC is less than/equal to breakpoint then
bacteria is susceptible to antibiotic
narrow spectrum agent (re. MIC)
low MIC for only a few bacterial types
antibiotic resistance genes are present on…
plasmids and chromosomes
streptomycin
aminoglycoside
protein synthesis inhibitor - targets 30S subunit
what modifies streptomycin
phosphotransferase
RNS family
reactive nitrogen species
no drug efflux pumps
MRSA
SSCmec gene
competence proteins
mediate natural transformation
conjugation
resistant gene moves with replication plasmid
resistance gene integrated along with phage DNA
transduction
vertical transmission via..
mitosis
transfer via mature cells
horizontal transmission
cause of antibiotic resistance
horizontal transmission
mecA
variant penicillin binding protein has lower affinity for B-lactam
cause of B-lactam resistance
mecA protein causes lower affinity for b-lactam
mannose receptor
receptor for PRRs
mediates phagocytosis
no inflammatory response
what uses mannose receptor
virulent strains of mycobacterium tuberculosis
how do L.pneumophilia survive in macrophages
by not progressing past an early endosome
how do S.typhimurium survive in macrophages
by not progressing into phagolysosome
how do M.tuberculosis survive in macrophages
by not progessing into late endosome
TLRs recognise
bacteria in vesicles
NLRs have
nucelotide binding oligomerisation domain
LRRs
listeriolysin
virulence factor
helps listeria enter cells
allows listeria to escape phagosome to cytoplasm
Salmonella use TLRs to…
find protective niche
then secrete proteins to cause further damage
properties of M.tuberculosis phagosome
vacuolar H+ATPase
inefficient lumenal acidification
few mature lysosomal hydrolyses
T3SS in macrophages cause
cell death
pyroptosis
pyroptosis
inflammatory cell death
occurs after infection with intracellular pathogens
rapid cell membrane rupture
steps of autophagy
isolation membrane sac forms autophagosome forms (double membraned) outer membrane fuses with lysosome autolysosome degradation of contents
xenophagy
autophagy targeting intracellular pathogens
autophagy of damaged mitochondria
mitophagy
aggrephagy
autophagy of protein aggregates
LC3 gene is responsible for …
autophagy
recruits phagosomal membrane
what represses autophagy
T3SS
Burkholderia pseudomallei
gram -ve
rod-shaped
found in soil and water
causes melioidosis disease
listeria autophagy pathways
persistant infection
successful fusion with lysosome
listeria produces LLO
helps them enter cell and escape phagosome
virulence genes maintain integrity of ….
scv - salmonella containing vesicle
TLR signalling prevents acidification of …
scv
when pH of scv decreases
no salmonella replication
ubiquitination tags..
proteins for proteasomal degradation
Burkholderia autophagy
1 - phagosome and lysis
2 - phagosome builds tail and escapes
3 - phagosomal escape and autophagy starts again - lysis
shigella flexneri evades degradation by ….
inducing cell death
phagocytes present antigens to…
T helper cells
CD8 present to
MHC I
CD4 present to
MHC II
MHC I killing pathways
via perforin
CD95 pathway
perforin pathway
pores allow granzymes to enter
which molecules present longer peptides
MHC II molecules
co-stimulation needed for…
CD4 T cell recognition
Th1 produces cytokines
IL-2
IFN-gamma
TNF-alpha
perforin and CD95 pathways both lead to
apoptosis
cytokines activate
B cells
turn into plasma cells
B cells
turn into plasma cells
produce specific antiviral antibodies
naked DNA vaccine
DNA makes proteins after injection
examples of live vaccines
BCG
typhoid
yellow fever
smallpox
genetic plasticity
the ability of one genotype to produce more than one phenotype when exposed to different environments
