Bacteria Flashcards
1
Q
Is E Coli gram -ve or +ve?
A
-ve
2
Q
Is MRSA gram +ve or gram -ve?
A
+ve
3
Q
Which cells are PMNs?
A
Basophils, eosinophils and neutrophils
4
Q
What is a regulon?
A
Operons regulated together
5
Q
What kind of DNA do bacteria have?
A
dsDNA circular
6
Q
Where are bacterial ribosomes?
A
Filling the cytosol
7
Q
What kind of mRNA do bacteria have?
A
polycistronic unstable
8
Q
What is the default bacterial shape?
A
Sphere
9
Q
Which actin homologue controls cell shape to produce a rod?
A
MreB
10
Q
Which tubulin ancestor localises at the midcell to form a ring?
A
FtsZ
11
Q
How many proteins does the flagellum contain?
A
40-50
12
Q
Which kind of bacteria have a periplasm?
A
Gram -ve
13
Q
Where are the beta lactamases found?
A
The periplasm
14
Q
Where are porin and LPS found?
A
Outer membrane
15
Q
What is removed in the Sec pathway?
A
N-terminal export signal
16
Q
Which kind of bacteria need additional transport pathways?
A
-ves
17
Q
Which kind of bacteria have TolC exit ducts?
A
-ves
18
Q
Which are the three lipopolysaccharides in gram -ves?
A
O-antigen, lipid A, core polysaccharide
19
Q
Which of the lipopolysaccharides are variable?
A
O-antigen
20
Q
What is the O-antigen important for defence against?
A
Complement and macrophages
21
Q
Which TLR recognises lipid A?
A
TLR4
22
Q
What crosslinks does peptidoglycan have vertically and horizontally?
A
Oligopeptide
23
Q
What acids do gram +ve bacteria have?
A
Teichoic
24
Q
What is the signal to produce endospores?
A
Lack of amino acids
25
What is the structure of an endospore?
Core and cortex
26
Where are the bacterial chemoreceptors?
"Nose"
27
Which way does the propeller rotate to move forwards?
Counter clockwise
28
What happens if the propeller goes clockwise?
Tumbles for random reorientation
29
What are His-Asp pathways?
Membrane signal transduction pathways which modulate operon networks
30
In high cell density, what are the virulence genes against?
Different strains
31
How do bacteria recognise a quorum?
Secrete a signal molecule and then sense its concentration using a positive feedback loop
32
Where are quorum genes switched on?
When there is enough of a bacterium's own type
33
What do adhesins bind to?
Host cells or the tissue matrix
34
What molecule do adhesins bind to?
Carbohydrates of glycolipids
35
Where are adhesins found?
The end of the pili
36
How are pili assembled?
From the inside out
37
What happens to pili subunits in the periplasm?
Bind to the chaperone
38
Which complex do adhesins bind to in order to start the pilus?
Usher
39
Which substances are used to form biofilms?
Adhesins and polysaccharides
40
Do pedestals or adhesins form tighter adhesions?
Pedestals
41
In pedestals, what delivers effector proteins into the host cell?
Needles
42
Which receptors are induced in pedestals?
Tir
43
What binds to Tir to promote actin polymerisation to form the pedestal?
Intimin
44
What is the zipper mechanism?
Receptor-mediated endocytosis
45
In the zipper mechanism, what mimics eukaryotic ligands?
Invasins
46
What do invasins do?
Bind integrins
47
What is the trigger mechanism?
Bacterium remains in vacuole
48
How does the bacterium promote endocytosis in the trigger mechanism?
Uses internalins
49
Which mechanism shows "ruffles"?
Trigger
50
What forms an actin tail to push the cell forwards?
ActA
51
How many genes do pathogenic bacteria have?
5000
52
Which bacterium has less genes?
Chlamydia - intracellular
53
What is the speed of mRNA turnover?
Fast
54
Which genes contain transposons contain?
Toxins/heavy metal resistance
55
What picks up transposons?
Extra-chromosomal plasmids
56
Where are most virulence genes found?
Pathogenicity islands
57
How do pathogenicity islands evolve?
Horizontal gene transfer
58
What is transduction?
Phage
59
What is conjugation?
Sex pilus then local lysis
60
What is transformation?
Natural uptake of DNA from dead lysed bacteria
61
What inhibits bacterial growth in the GI tract?
Gastric acid and bile salts
62
What breaks down peptidoglycan?
Lysosome
63
What is iron sequestered by to reduce bacterial growth?
Lactoferrin and transferrin
64
What binds to the bacterial cell membrane to form a pore?
Defensins
65
Which TLR does flagellin activate?
TLR5
66
Which TLR does peptidoglycan activate?
TLR2
67
Which TLR does unmethylated DNA activate?
TLR9
68
Which TLR does LPS activate?
TLR4
69
Which complement pathway does LPS activate?
Alternative
70
What does CRP bind to when acting as a PRR?
Phosphocholine
71
Which kind of bacteria is the MAC effective against?
Gram -ves
72
What is the C3b receptor?
CR1
73
Which proteins react with cardiac cells and contribute to autoimmune disease?
Streptococcal M proteins
74
What structure do macrophages use to kill?
Phagolysosomes
75
What do macrophages bind to?
Lectins
76
What do phagolysosome granules contain?
Lactoferrin and NADH peroxidase
77
Which pigment does myeloperoxidase have?
Haem
78
Where is myeloperoxidase found?
Neutrophil lysosome
79
What causes the green appearance in neutrophil-rich secretions?
Myeloperoxidase
80
Are CTLs important during induced immunity?
No
81
What does Th1 activate in induced immunity?
Macrophages
82
What does Th2 cause production of during induced immunity?
Igs
83
What activates classical complement?
Pre-existing antibody binds C1q or CRP
84
What does the lectin complement pathway recognise?
Mannose
85
What does mannose activate?
MASP
86
Which kind of bacteria have capsules?
Those causing pneumonia
87
What does the O-antigen prevent formation of?
MAC
88
How do bacteria change the O-antigen to mimic the host?
Attach a sialic acid to it
89
By which mechanism do bacteria switch surface antigens?
Phase variation
90
Which bacteria use enzymes to spread?
Staph and strep
91
Which bacteria cause endemic mastitis?
Staph and strep
92
Which enzymes break down connective tissue?
Collagenase and hyaluronidase
93
What do siderophores do?
Bind iron and reimport it into the cell
94
How can bacteria inhibit chemotaxis?
Use a peptidase to cleave C5a
95
Where do proteases cleave IgA?
Near the hinge
96
What do cytolysins do to the host cell membrane?
Degrade phospholipids or form pores
97
What is the A of an AB toxin?
Active
98
What is the B of an AB toxin?
Receptor binding
99
What do AB toxins do to single polypeptides?
Cleave them into fragments
100
What is the structure of AB toxin?
Either have disulphide bridges or are multimeric
101
How do AB toxins enter the cell?
Receptor mediated endocytosis and retrograde transport
102
What do superantigens bridge?
The TCR and MHC
103
What cytokines do superantigens cause a storm of?
IL-1, IL-2, TNF
104
What are the two kinds of bacterial toxins?
Cytolysins and enzymatic intracellular toxins
105
Which body part do bacteria causing meningitis colonise?
Nasopharynx
106
What are meningitis-causing bacteria capsulated with?
Sialic acid
107
Which protease do meningitis-causing bacteria secrete?
IgA
108
What do penicillin-resistant bacteria cleave penicillin to?
Penicilloic acid
109
Which subunit does chloramphenicol bind to?
50S
110
Which enzymes does chloramphenicol inhibit?
Peptidyl transferase
111
Which subunit do aminoglycosides alter?
16S rRNA
112
Which processes do aminoglycosides inhibit?
tRNA selection and peptide elongastion
113
What enzymes do bacteria resistant to aminoglycosides produce?
Acetyltransferases
114
Which subunit does tetracycline bind to?
30S
115
Which process does tetracycline inhibit?
Aminoacyl tRNA binding
116
Which proteins do bacteria produce to dislodge tetracycline?
Ribosomal Protection Proteins
117
What are RPPs similar to?
Translocation elongation factors
118
Which enzymes do fluoroquinolones inhibit?
Topoisomerases
119
Which resistance protein blocks topoisomerase and prevents antibiotic binding?
Qnr
120
Which enzymes does vancomycin block access to?
Transpeptidase
121
Which enzymes do vancomycin-resistant bacteria encode?
PBPs (variant transpeptidases)
122
What is vitamin B9?
Folate
123
What does sulphonamide compete with?
pABA
124
Which enzyme does sulphonamide inhibit?
DHPS
125
Which enzymes does trimethoprim inhibit?
DHFR
126
How is the affinity different in R-plasmid encoded versions?
Lower
127
What is the source of energy for transporting the antibiotic through the periplasm?
ATP hydrolysis
128
Which enzyme does clavulanic acid inhibit?
Beta-lactamase
129
Which toxins do Shigella produce?
ShET1 and ShET2
130
What can haemophilus influenzae cause?
Pneumonia and meningitis
131
Which strep pyogenes protein binds C1q?
Endopeptidase O
132
Which bacteria cause meningitis?
E. Coli, Strep pneum, Neisseria m and pharyngis, H. influenza
133
Which bacteria cause pneumonia?
Strep pneum, haem influenzae
134
Which kind of bacteria cause meningitis?
Encapsualted
135
Which toxins does E. Coli produce?
Haemolysins, CDTs, cytotoxic necrotizing factor
136
What do CDTs do?
DNAse genotoxin
137
What does cytotoxic necrotizing factor do?
Deamidase, targets GTPases, disrupts actin cytoskeleton
138
Which toxins do UPEC produce?
haemolysin, cytotoxic necrotizing factor
139
Which toxin does EHEC produce?
Shiga-like toxin (N-glycosidase to modify rRNA, block translation, break down vascualture)
140
Which toxin does ETEC produce?
Labile Toxin (cholera-like enterotoxin)
141
Which toxin does salmonella produce?
CDT
142
Which toxin does salmonella typhi produce?
CDT
143
Which toxins does vibrio cholera produce?
AB (for receptor mediated endocytosis) and fixes Gs on
144
Which toxins does helicobacter produce?
VacA (ion channel) and CagA (cell proliferation)
145
Which toxin does C. tetani produce?
AB
146
Which toxin does C/ botulinum produce?
AB
147
Which toxin does C. difficile produce?
Glucosylase (glycosylate and inhibit Rho/Ras GTPases causing cytokeleton and tight junction destruction)
148
Which inactivate IgA protease?
Neisseria, strep pneum. E. Coli, H. influenzae
149
Which siderophore does pseudomonas aeruginosa produce?
Pyoverdin
150
Which toxin does staph aureus produce?
Alpha-toxin
151
Which toxins do strep pyogenes produce?
Streptolysins O and S, C5a peptidase, DNAse
152
Which iron binding sideophore does strep. equi produce?
Equibactin
153
Which bacteria is anti-complement?
Strep. pyogenes
154
Which toxins does Shigella produce?
Shiga toxin, SHET1 and SHET2
155
What does Yersinia "yops" do?
Subvert macrophages
156
Which toxins does Strep. pneum. produce?
Pneumolysin,
157
What effector protein facilitates lysis in M. tuberculosis?
ESAT6
158
Which toxins does Corynebacterium diphtheriae produce?
AB DTX, one to ADP-ribosylate EF2 and prevent translation,
159
Which toxins does bordetella pertussis produce?
Multimeric AB, ADP-ribosylates adenyl cyclase regulators, adenylate toxin homologues
160
Which toxins does bacilla anthracis produce?
Multimeric AB, adenylate cyclase homologue
161
Which toxin does Campylobacter produce?
CDTs
162
Which toxins does Corynebacterium ulcerans/pseudoTB produce?
AB, one which ADP-ribosylates EF2
163
Which bacteria ADP-ribosylate EF2?
Corynebacteria
164
Which membrane has TolC?
Outer
165
Which enzyme does ciprofloxacin inhibit?
DNA-dep RNA pol
166
Is H pylori gram positive or negative?
Negative
167
What does Shiga-like toxin cause in children?
Uraemic syndrome
168
Are bacteria haploid?
No
169
What do salmonella pathogenicity islands contain?
SPI-1 and SPI-2
170
Which receptor does lipid A activate macrophages by?
Cd14
171
How many genes has chlamydia got?
900
172
Which bacteria have LPS?
Negative only
173
Which bacteria lack a cell wall?
Chlamydia and Mycoplasma
174
How do anaerobes gain energy?
Fermentation using electron acceptors such as iron
175
How long are insertion sequences?
A few hundred BP
176
Which nucleotides differ in pathogeniity islands?
CG
177
What do SPI-1 do?
Determines entry into non-phagocytic cells
178
What does SPI-2 do?
Survival in macrophages
179
Which bacteria forms plaque on teeth?
Strep. mutans
180
Which bacteria colonise catheters?
Staph
181
Which bacteria colonise contact lenses?
Pseudomonas aeruginosa
182
Which condition predisposes to to P.aeruginosa biofilm in the lungs?
Cystic fibrosis
183
Which eukaryotic ligands do trigger proteins mimic?
SipA, SipC, SptP
184
What does YopT do?
Targets GTPases to disrupt cytoskeleton
185
What does YopP do?
Acetyltransferase that inhibits signalling triggering apoptosis
186
Whcih transcription factor represses C. diff gene expression when bound by iron?
DtxR
187
What is receptor for DTX?
HB-EGF
188
Which host protease nicks the DTX polypeptide?
Furin
189
Which Lancefield group is S. equi?
C
190
Where does C perfringens germinate from?
Spores in pre-heated foods
191
Which bacteria remains in a membrane bound vacuole?
Salmonella
192
Where are S.typhi bacteria shed?
Bile
193
Which C difficile toxins are produced?
TcdA and TcdB
194
What do C difficile toxins do?
Glycosylate GTPases
195
Which bacteria can be live attenuated?
Salmonella
196
Which drug are meningitis E coli becoming resistant to?
Ciprofloxacin
197
What does chloramphenicol inhbit?
Peptidyl transferase
198
What does aminoglycosides inhibit?
tRNA selection adn polypeptide elongation
199
Resistance to tetracycline?
RPP to dislodge it
