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Flashcards in bacteria: part 2 Deck (20)
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1

Normal 3 tpes of naceria

Cocci, bacilli, spiral

2

How does flagella and pili contribute to virulence

Flagella (movement, attachment) Pili (important adherence factors)

3

How does biofilms contribute to virulence. Examples

(organized agregrates of bacteria embedded in polysaccahride matricesi. e. Pseudomonas aeruginosa i.e. Staphylococcus epidermidis

4

Outline neurotoxin wiht examples

act on nerves or motor endplate i.e. Tetanus or Botulinum toxins

5

What is endotoxin released by

Only produced by Gram-negative bacteria

6

What is endotoxin

Not a protein but it's the the lipid A moiety of LPS

7

What is haemolytic-uraemic syndrome

triad of acute renal failure, hemolytic anemia and thrombocytopenia

8

What are E.coli strains which release shiga toxin known as

EHEC enterohemorrhagic E. coli

9

When does human infection with EHEC often occur

occurs through the inadvertent ingestion of fecal matter and secondary through contact with infected humans

10

Why can a shiga toxin bacteria infection affect gut microbiota

Bacterial ribosomes are also a substrate for StxA and this will result in decreased proliferation of susceptible bacteria might affect the commensal microflora in the gut

11

When are shiga toxins highly expressed

Toxins are highly expressed when the lytic cycle of the phage is activated (so that the gene can be taken up by lots of E coli)

12

What is the impact of AAF bunding to enterocytes with regard to human immune response

AAF stimulate a strong IL-8 response

13

What type of bacteria are TB and legionella pneumophilia

TB=gram +ve Legionella=gram -ve

14

List common bacterial STI

Chlamydia trachomatis infection Gonorrhoea Syphilis

15

What type of bacteria is each of Chlamydia trachomatis Neisseria gonorrhoeae Treponema pallidum

Gram neg

16

What cells does N gonorrhoeae interact with

Establishes infection in the urogenital tract by interacting with non-ciliated epithelical cells

17

Virulence factor of Campylobacter sp. mostly C. jejuni

Adhesion and Invasion factors, Flagella motility, Type IV Secretion system, Toxin

18

Important virulence factor with vibrio cholerae

type IV fimbria cholera toxin carried on a phages

19

How does the cholera toxin work

Binds to enterocyte Through b pentamer to the GM1 ganglioside receptor on enterocyte A/B cholera toxins cleves A1 domain from A2 domain, activating A1. A1 faragment enters cytosol, activates Gsa, continually stimulating AC to produce cAMP. High cAMP activates CFTR... efflux of ions (esp chloride) and water from infected enterocytes Leads to diarrhoea

20

How does listeria infect

Listeria can enter non-phagocytic cells and cross three tight barriers Intestinal barrier, Blood / brain barrier and Materno / fetal barrier