Download Molecular Biology of Bacterial Disease: Key Concepts and Mechanisms and more Exams Biology in PDF only on Docsity!
Infection |- |correct |answer |✔colonization |of |the |body |by |an |organism |capable |of |causing |disease Disease |- |correct |answer |✔infection |that |causes |symptoms Colonization |- |correct |answer |✔bacteria |occupies |and |multiplies |in |the |human |body Carrier |- |correct |answer |✔infection |is |asymptomatic Virulence |- |correct |answer |✔ability |of |bacteria |to |cause |disease Virulence |factor |- |correct |answer |✔gene/protein |required |for |disease Koch's |Postulates |- |correct |answer |✔1) |The |microbe |must |be |consistently |shown |to |be |present |in |the |diseased |tissue |and |not |in |healthy |tissue.
- |The |microbe |must |be |isolated |and |grown |in |culture |in |pure |form.
- |The |pure |culture |must |be |shown |to |induce |the |disease |anew.
Issues |with |Koch's |postulates |- |correct |answer |✔1) |sometimes |there |are |asymptomatic |carriers; |Typhoid |Mary
- |It |can |be |difficult |to |culture |some |organisms
- |This |relies |on |animal/cell |culture |model. |Some |diseases |may |only |affect |humans. "Improved" |Koch's |postulate |- |correct |answer |✔1) |genes |must |be |present |in |pathogen |that |is |not |in |avirulent |strains.
- |Removal |of |virulence |gene |in |pathogen |creates |an |avirulent |phenotype.
- |Expression |of |virulence |gene |or |genes |in |an |avirlent |organism |should |result |in |a |virulent |phenotype. Genetic |approach |to |isolate |and |Characterise |InvA |mutant |- |correct |answer |✔1) |grow |mammalian |epithelial |cells |on |petri |dish |then |add |bacteria.
- |Incubate |to |allow |bacteria |to |bind/internalize
- |add |antibiotic |that |kills |(inv-) |salmonella |but |cannot |enter |epithelial |cells. |
- |Remove |media |and |destroy |epithelial |cells |with |a |detergent |that |doesn't |harm |bacteria. |then |Count |cells |present.
- |Grow |strain |on |agar |for |isolatin invA |- |correct |answer |✔a |gene |that |allows |Salmonella |cells |to |invade |epithelial |cells |through |an |Injectisome. |Making |them |inv+. Inv- |- |correct |answer |✔salmonella |cells |that |do |not |have |invA |gene, |therefore |cannot |pass |through |epithelial |cells. |They |can |only |attach |to |the |cell |surface. |can |still |be |as |virulent |as |inv+ |if |injected |past |the |epithelial |membrane
Major |Functions |of |the |Complement |system |- |correct |answer |✔1) |Phagocytosis |via |FC |receptor/C3b |receptor
- |Recruitment |via |chemotaxis
- |Lysis |via |membrane |attack |complex MHC-I |(Major |Histocompatibility |Complex) |- |correct |answer |✔Adaptive |immunity |pathway. |It |displays |antigens |on |cell |surface |when |bacteria |has |infected |the |inside |of |the |cell. |The |T |cells |response |to |this |display |is |to |kill |the |host |cell. MHC-II |(Major |Histocompatibility |Complex) |- |correct |answer |✔Also |adaptive |immunity |pathway. |It |displays |antigens |on |cell |surface |from |bacteria |that |are |phagocytized. |The |T-cells |respond |to |this |display |by |producing |antibodies CD-1 |- |correct |answer |✔Antigen |display |of |glycolipids. |it |can |activate |either |the |T-helper |cell |(antibody |production) |or |the |cytotoxic |T |cell |(lysis). Superantigens |- |correct |answer |✔secreted |proteins |made |by |bacteria |that |cause |T |cell |receptor |to |interact |with |empty |MHC-II |proteins. |This |causes |T-cells |to |produce |cytokines. |Same |as |SEPSIS. Diptheria |toxin |- |correct |answer |✔B |subunit |makes |hole |in |host |cell |and |A |subunit |enters |cell.It |then |takes |ADP-ribose |from |NAD |and |binds |it |to |EF-2. |this |inactivates |EF-2 |and |stops |protein |synthesis. Shiga |toxin |- |correct |answer |✔Also |A |and |B |subunits. |Toxins |RNA |glycosidase |cleaves |adenine |base |of |the |ribosome |which |inhibits |tRNA |binding |to |ribosome |for |protein |synthesis
Anthrax |- |correct |answer |✔Also |A |and |B |subunits. |Lethal |factor |is |released |into |the |cytoplasm |and |inactivates |MAPKK. |Inactive |MAPKK |impaires |both |innate |and |adaptive |immunity, |supresses |inflammation, |Endothelial |cell |apoptosis Botulism |toxin |and |Tetanus |- |correct |answer |✔Blocks |neurotransmitter |release |which |results |is |paralysis. Outer |membrane |vesicles |- |correct |answer |✔Produced |by |all |Gram-negative |bacteria |and |is |formed |from |the |outer |membrane |of |the |cell. Outer |membrane |vesicle |functions |- |correct |answer |✔1) |promote |biofilm |formation
- |Export |of |enzymes
- |Removal |of |unfolded |proteins |from |the |periplasm
- |Vesicles |used |as |decoy |target |for |immune |recognition
- |Mediate |DNA |transport
- |Environment |for |folding |proteins
- |Export |of |virulence |factors |to |host |cells |and |tissues Horizontal |gene |transfer |- |correct |answer |✔Bacteria |gaining |new |DNA. |It |allows |resistance |genes |to |be |spread |among |bacteria |following |the |introduction |of |an |antibiotic Horizontal |gene |transfer |mechanisms |- |correct |answer |✔1) |Plasmids |spread |by |Conjugation |(tunnel |between | 2 |cells) |
Alanine-lactate |- |correct |answer |✔makes |up |the |end |of |the |peptide |in |peptidoglycan |instead |of |the |D-ala-D-ala. |So |the |target |that |vancomyosin |binds |to |has |changed. Tetracycline |- |correct |answer |✔antibiotic |that |stops |protein |synthesis |by |binding |to |ribosome |subunit. Efflux |Pumps |- |correct |answer |✔tetracycline |resistant |protein |that |pumps |the |antibiotic |out |of |the |cytoplasm. |Active |transport, |typically |replacing |tetracycline |with |ion. TolC/chunnel |- |correct |answer |✔can |pump |tetracycline |out |of |both |the |outer |and |inner |memrbanes Cationic |peptides |and |collistan |- |correct |answer |✔short |peptides |on |macrophages |that |contain |positive |charged |amino |acids |that |detect |negative |charged |molecules |(lipid |A |of |bacteria) |They |form |pores |in |bacterial |membrane MCR-1 |- |correct |answer |✔a |gene |in |bacteria |that |evade |macrophage |detection |by |neutralizing |their |negative |charges |of |their |LPS's |with |positive |charge. ICE |- |correct |answer |✔Integrative |conjugative |element, |they |can |transfer |through |cell-cell |contact |and |integrate |into |the |chromosome |of |the |new |host |cell. SXT |- |correct |answer |✔an |ICE |element |in |V.cholerae
SetCD |- |correct |answer |✔activates |transcription |of |SXT SetR |- |correct |answer |✔a |repressor |of |SXT |by |binding |to |the |setCD |promotor SOS |response |- |correct |answer |✔response |to |cell |damage |to |try |to |repair |cell. |It |alleviates |the |SetR |repressor |to |allows |transcription |of |SXT. RecA |- |correct |answer |✔The |protein |that |senses/binds |to |single |stranded |DNA. |This |inactivates |the |LexA |repressor |which |turns |on |the |SOS |response. LexA |repressor |- |correct |answer |✔represses |the |genes |for |the |SOS |response. |It |only |allows |transcription |of |the |SOS |response |once |RecA |has |inactivates |this |repressor. Mitomyocin |C |- |correct |answer |✔produces |damage |in |the |cell |to |induce |the |SOS |response |which |promotes |SXT |transcription |when |SetR |is |present |in |the |bacteria |. Does |SXT |movement |require |RecA? |- |correct |answer |✔Yes, |bc |cell |damage |needs |to |be |recognized |inorder |to |induce |the |SOS |response |that |elevates |the |SetR |repressor.
