Mikrobiologi Flashcards
(116 cards)
1
Q
Granules
A
Reserve deposits for accumulation of nutrients (glycogen, phosphate, lipids etc.)
2
Q
Septum
A
Location in membrane where cell division takes place
3
Q
Peptidoglycan
A
Most important component in cell-wall: made up of NAG & NAM
4
Q
Gram positive cell wall
A
Thick layer of peptidoglycan (≈90% of cell wall)
Contains techoic acid and lipotheicoic acids. Only in G+ bacteria
5
Q
Gram negative cell wall
A
Thinner peptidoglycan.
Outer and inner membrane. Outer membrane contains phospholipid, LPS and proteins.
Periplasm: mellan outer och inner membrane, contains hydrolytic enzymes.
6
Q
LPS
A
Contains: Lipid A
Core polysaccharide
Antigen O
7
Q
Smooth swimming
A
Rotation CCW -> inward force -> linear movement
8
Q
A tumble
A
Rotation CW -> outward force -> tumble
9
Q
Taxis
A
Motile response to an environmental stimulus ex. chemicals, light, osmotic pressure etc.
10
Q
Chemotaxis
A
Bacteria can move toward chemically favourable environments
11
Q
Pili/Fimbriae
A
Present in G- and G+ bacteria.
Used for adhesion and recognition to specific receptors
12
Q
F-pilus
A
Function to transfer of DNA among bacteria (conjugation), F-pili
13
Q
Endospores
A
Differentiated cells very resistant to heat and not easily destroyed.
Has thick protein coat and components for regeneration & vegetative growth.
14
Q
SASPs
A
Small acid- soluable proteins made during sporulation. Binds to DNA and protects it from damage.
15
Q
Binary fission (Phases)
A
Asexual reproduction by bacterial division:
1 Lag phase
2 Exponential phase
3 Stationary phase
4 Death phase
16
Q
Generation time
A
Time to accomplish cell-cycle by exponential growth.
17
Q
Total cell count
A
Number of bacteria in square/ volume
18
Q
Viable count
A
Measures only alive bacteria
19
Q
Turbidity (optical density)
A
Alve & dead
20
Q
Gram staining
A
Gram + or -
21
Q
Giemsa staining
A
Mainly parasite and virus detection
22
Q
Organelle specific staining
A
Phalloidin- actin structures
23
Q
RFLP analysis
A
Restriction fragment length polymorphism.
Restriction sites: specific sites of ds cleavage by enzymes.
24
Q
Monocistronic operon
A
When it contains only one open reading frame
25
Polycistronic operon
When it contains more than one ORF
26
Operator
Regulation of gene expression is controlled
27
Promoter
RNAP binds
28
Terminator
Where transcription stops
29
Shine dalgarno
Ribosome binding site
30
Phase variation
ON/OFF expression
31
Recombination
Antigenic variation
32
Regulon
Several genes and or operons respond to same regualtory protein/ sigma factor
33
Stimulon
Group of genes and or operons that respond to the same signal but not the same pathway
34
Activator (co-activator)
Co-activator acts as dimer so binding is better and closer to consensus sequence
35
Repressor (co-repressor)
Block RNAP binding to promoter
36
Feric uptake regulator
Adjust iron levels inside bacterium.
*Fur repress expression of genes important for stress regulation and virulence factors
*Iron acts as co-repressor
37
MIC
MInimal inhibitory concentration
38
MBC
Minimal bactiercidal concentration
39
Broad spectrum antibiotic
POlymicrobial infection
40
Narrow spectrum antibiotic
Infection caused by single pathogen
41
Types of antibiotics (mechanisms)
1 Inhibition of cell wall synthesis
2 Inhibition of protein synthesis
3 Alteration of cell membranes
4 Inhibition of nucleic acid synthesis
5 Inhibition of folate synthesis
6 Increased protease activity
42
β-laktam
Interferes with peptidoglycan synthesis
43
Vancomycin
Disrupts peptidoglycan cross linkage
44
Aminoglycosides
Binds to 30S subunit proteins and changes its shape => mRNA is misread
45
Quinolones
Inhibits DNA gyrase required for supercoiling
46
Sulfonamides
Competes with p-aminobenzoic acid, preventing synthesis of folic acid
47
Trimetoprim
Inhibits synthesis of tetrahydrofolic acid, competing with DHF
48
Isoniazid
Against tuberculosis.
Inhibit mycolic acid synthesis, which interferes with cell wall synthesis.
49
Rifampicin
Affects RNA- synthesis, through binding to RNAP
50
Chloramphenicol
Binds at entrance to the peptide tunnel and inhibits formation of peptide bonds between amino acids.
51
Indifference
1+1 = 1
52
Additative effect
1+1 = 2
53
Synergistic effect
1+1 >2
54
Antagonistic effect
1+1 < 1
55
Intrinsic resistance
Bacterium not sensitive to antibiotic of choice
56
Acquired resistance
Resistance acquired via either uptake of gens or mutational vents in the genome
57
Transformation
Lysis of parent bacteria - release of naked DNA
58
Transduction
Incorporation of chromosomal parent DNA into bacteriophage
59
Conjugation
Physical contact between two bacterial cells via F-pilus
60
β-lactamase
Hydrolyse the β-lactam ring of the antibiotic
61
Prophages
When a phage has incorporated its genome in the bacterial chromosome
62
Plasmids
Genetic elements most often replicating autnomously of the core genome
63
Transposons
DNA that can jump between genetic locations on the chromosome
64
Episome
Plasmids that can be integrated into the genome
65
R-plasmids
Resistance plasmids: can carry genes that confers resistance to penicillins, chloramphenicol, kanamycin, tetracycline, streptomycin, sulfa
66
RTF
Resistance transfer factor ex. conjugative plasmid
67
R determinant
Resistance genes
68
Transposition
Movement of transposons (Tn5, Tn10), catalyzed by transposase
69
IS-elements
Insertion elements
70
Insertion sequences
Elements carry no other genes except those involved in transposition (IS1, IS2)
71
Non- replicative transposition
The transposon is cut out with the help of the transposase and then inserted at another place
72
Replicative transposition
The transposon duplicates and a copy is incorporated at another place
73
Integrons
Genetic elements often carrying antibiotic resistance genes. Most integrons originates from transposons.
Require:
1 Integrase IntI => allow incorporation of new genes
2 attI recombination site => where incorpration occur
3 Promoter => allow high expression of incorporated gene
74
Transformation
Bacteria take up naked DNA
75
Transduction mechanism
Transfer of DNA by bacteriohage.
Infection of host cells: T4
1 Adhesion: carried out by tail, reversible & specific. LPS surface proteins, pili, lipoproteins as receptor molecules
2 Attachment: irreversible, mediated by base plate
3 Penetration: sheath concentration, hollow tail fiber crosses bacterial envelopes
4 Genome injection: usually only genom pass through
76
Virulent phage
Can only multiply within the bacterium and kills the cell via lysis ex. T4
77
Temperate phage
Can either multiply within the bacterium or rest dormant in the genome of the bacterium ex. λ
78
Lysogen
Host cells containing a phage
79
Induction
When a lysogenic bacterium is exposed to adverse conditions the lysogenic phase may end
80
Generalized transduction
Infection
-> Phage replication, breakdown of host cell DNA
-> Release of new phages
-> Homologous recombination in new bacterium
81
Specialized transduction
Excision of the prophage
-> Replication and release of the phage
-> Infection of recipient
-> Lysogeny of recipient
82
Conjugative plasmids
Contains genes for transference ex. tra genes and oriT.
83
F'
Chromosomal excision of F plasmid, in process it acquires som extra genes
84
F' x F- crossing
Spread of chromosomal DNA among bacteria
85
Fungus
*Eukaryot
*Fakultativ anaerob eller obligatorisk aerob
*Kemotrop
*Cellvägg av kitin
86
Anti- fungala läkemedel
*Membranförstörande substanser
*Ergosterolsynteshämmare
*DNA-synteshämmare
*Förtrycker spindel (mitos)
*Glukansynteshämmare
*Kitinsynteshämmare
*Proteinsynteshämmare
87
Kutana svampinfektioner
Dermatofyter bryter ned keratin m.h.a keratinaser.
88
Orsak dermatofytos
Kontakt, trauma, fuktighet, trångboddhet, cellulär immunbrist.
89
Dermatofytos terapi
Håll huden ren och torr, lokal applicering, kroniska infektioner och nagel infektioner kräver systemisk medicinering
90
Histoplasmos
Systemisk mykos: Infektion av lungorna orsakas av histoplasma capsulation
91
Opportunistiska mykoser
Orsakande agens: saprofyter i naturen
kommensala
Värd: immunosupprimerad
Ytterligare faktorer: långvarig antibiotikabehandling, ålder
92
Kandidos
Orsakande agens: Candida albicans
ex. vaginala infektioner eller ytliga infektioner av huden eller munhålan.
93
Cryptococcus neoformans
Initial lunginfektion. Lunginflammation vid immunosupprimerade tillstånd.
94
Intestinal microbiota functions
Assist with digestion, synthesize vitamins, immune tolerance
95
Symbiosis
Relationship between 2 different kinds of living organisms that live together and depend on each other
96
Mutualism
Both bacteria and host benefit from the association
97
Commensalism
Bacteria benefits from the association, but this neither benefits nor causes harm to the host
98
Parasitism
Often the bacteria causes harm to the host
99
Bacterial pathogen
Bacterium capable of causing disease in host.
Any commensal bacterium has this potential.
100
Opportunistic pathogens
Bacteria which causes disease in compromised host which typically would not occur in healthy host.
Can be part of microbiota or a free living environmental bacteria
Do not cause harm in host unless opportunity arises by some compromise or weakness in host's anatomical barriers, tissue or immunity.
101
Infection process pathogenic bacteria
1 Reservoir
2 Gain entry, attach and colonize
3 Invade host cells
4 Gain access to nutrients and multiply
5 Evade host immune response: changing surface apparance, complement activation & phagocytosis, recognition etc.
6 Spread to other sites causing tissue damage
102
Actin polymerization
Generates movement to invade host cells => cell spreading
103
Antigenic shift
Major changes in the viral genome, genetic material from different strains is combined by reassortment
104
Antigenic drift
New mutations are continually introduced to genome cause enzyme is prone to mistakes
105
Endotoxins
Naturally occuring components of all bacteria
Release via bacterial cell lysis
Causes fever, changes in BP etc.
106
Exotoxins
Secreted toxins or enzymes, cause damage to cell by destroying cells or disrupting normal cellular metabolism.
107
Exotoxins types
Type I: cell surface, bind receptor, intracellular signalling
Type II: disrupt PM, channel-forming toxins, pore forming toxins modulate autophagy
Type III: intracellular toxins-> must be able to gain access to cytoplasm of target cell
Type IV: Breaks bond between proteins in connective tissue
108
Chlamydia
Gram negative, obligate intracellular bacteria, ability to import ATP
109
Avoidance of adaptive immunity syphilis
Unusual outer membrane: limited surface antigenicity, no LPS, very few outer membrane proteins, phase and antigenic variation
110
Mycoplasma pneumonia
No cell membrane -> not able to determine through Gram staining
111
Heliobacter pylori
H. pylori vidhäftar till celler med blodgruppsantigen
112
Heat stable toxin
Guanylatecyclaseactivated cGMP level increased => reduced uptake of water & ions
113
Heat labile toxin
Like cholera toxin. Adenylylcyclase activated cAMP level increased => increased secretion of water & ions
114
EPEC attachment
Type III secretion => translocates its own ligand-binding receptor "Tir" into the PM of host cells.
115
Vibrio cholera
Susceptible to stomach acids
116
Guillain Barré syndrome
An autoimmune disorder of PNS
