microbio chapter 20 (G-)

Question 1

Gram - Bacteria

Answer 1

• constitute largest group of human bacterial pathogens
• due in part to lipid A on outer membrane
• most grow at mesophilic conditions

Question 2

Neisseria gonorrhoeae (gonococcus)

Answer 2

• also called gonococcus
• causes gonorrhea
• gonococci attach to genital, urinary, and digestive tract

Question 3

Gonorrhea in men

Answer 3

painful urination and pus filled discharge

Question 4

Gonorrhea in women

Answer 4

often asymptomatic but can trigger pelvic inflammatory disease
- infection in children can occur during childhood

Question 5

Common case of Gonorrhea

Answer 5

occurred in Colorado when people were having sex for drugs

Question 6

How can Gonorrhea stick in our urinary tract when urine runs through it?

Answer 6

Gonorrhea cells contain Opa which is an intimate attachment outer membrane protein that allows it to adhere to our urinary tract

Question 7

What is the function of Opa and in which bacteria is it found?

Answer 7

Opa is an intimate attachment outer membrane protein that allows gonorrhea cells to adhere to the urinary tract

Question 8

What is the significance of gonorrhea adhering in the urinary tract?

Answer 8

• it is a hard place to get antibiotics to stick and an immune response to occur
• antibiotics do NOT stick well so they are not effective
• this allows a good environment for bacteria to grow

Question 9

What is the best antibody for gonorrhea?

Answer 9

slgA

Question 10

What does gonorrhea have to combat slgA

Answer 10

gonorrhea has proteases that cleave the antibody

Question 10

LOS in gonorrhea

Answer 10

• outer membrane lipopolysaccharide
• inhibits C3b binding on to bacterial membrane
• limits C5 convertase production
• limits C3b binding to surface (does not bind to CR1)
• triggers inflammation

Question 10

Diagnosis of gonorrhea

Answer 10

Gram- diplococci in pus from inflamed penis
- if asymptomatic genetic probes can be used

Question 11

Treatment of gonorrhea

Answer 11

broad spectrum antimicrobial drugs

Question 12

Prevention of gonorrhea

Answer 12

sexual abstinence

Question 13

Communal immunity of gonorrhea

Answer 13

• little to no long-term immunity due to changing surface proteins
• infection can occur in same individual many times
• fairly communal

Question 14

Enterobacteriaceae

Answer 14

• in the intestinal microbiota of most animals and humans
• ubiquitous in soil, water, and decaying systems
• most common Gram-pathogens of humans

Question 15

Escherichia coli

Answer 15

• coliform opportunistic Enterobacteriaceae
• most common and important of the coliforms
• virulent strains have virulence plasmids
• gastroenteritis is a common disease
• common cause of non-nosocomial urinary tract infection

Question 16

E. coli 0157:H7

Answer 16

• pathogenic strand
• most prevalent in developed countries
• causes diarrhea, hemorrhaging, hemolytic uremic syndrome
• ~2100 hospitalizations per year
• undercooked meat is the problem

Question 17

Jack n the Box E. coli

Answer 17

they served undercooked burgers to many children, and they went to the hospital
- many died
- many had irreversible kidney damage
- occurred in 1993

Question 18

E. coli toxins

Answer 18

• has a Shiga like toxin from Shigella
• believed to be passed through transduction
• contains SLT gene

Question 19

SLT gene

Answer 19

• an A-B toxin
• A= modifies rRNA in ribosomes bringing translation to a halt
• causes diarrhea/vomiting

Question 20

Truly pathogenic Enterobacteriaceae

Answer 20

• salmonella
• shigella
• yersinia
• almost always pathogenic due to virulence factors
• produce a type 3 secretion system

Question 21

Type 3 secretion system

Answer 21

• introduce proteins that inhibit phagocytosis, rearrange cytoskeleton, or induce apoptosis
• acts as a syringe to push in A-H protein

Question 22

Type 3 secretion system process

Answer 22

1. A-H protein is put into cell and cell is tricked into taking it in
   - A-H protein modifies membrane of phagosome with bacteria
2. phagosome cannot bind with lysosome
3. a separate type 3 secretion releases more A-H protein
4. cell with salmonella has to die in order to release bacteria
5. adjacent cell can uptake salmonella that is released from dying cells

Question 23

Salmonella exposure

Answer 23

Salmonella is constantly exposed to our immune system as it is released from cell to cell

Question 24

Salmonella

Answer 24

- ~2M cases/year - very low death rate - Gram -, motile bacilli - can be found in intestines and feces of birds, reptiles, and mammals - most human infections are due to consuming food with animal feces contamination - poultry and eggs are a common source - causes salmonellosis and typhoid fever

Question 25

Salmonella in our cells vs test tube

Answer 25

when salmonella A-H protein cells are grown in human cells, many proteins expressed in humans that do not appear in test tubes

Question 26

Salmonellosis

Answer 26

1. salmonella cells attach to epithelial cells in small intestine 2. bacteria triggers endocytosis 3. A-H protein prevents binding to a lysosome so bacteria grows in phagosome 4. salmonella kills host cell which induces fever, diarrhea, and cramping 5. bacteria can move into bloodstream

Question 27

Salmonella's O side chain

Answer 27

- has a longer O side chain that affect MAC complex - it signals MAC complex away from inner membrane - binds to C9 to disrupt completion of MAC - MAC can bind to O-side chain but it is too far to make holes in the membrane

Question 28

Mary Mallon cook

Answer 28

- asymptomatic carrier of Salmonella - was a cook and would pass on infection to others - was quarantined but found work again - eventually quarantined until her death in 1938 - confirmed to cause 55-122 typhoid fever cases

Question 29

Yersinia

Answer 29

normal pathogen of animals 1. Yersinia enterocolitica 2. Yersinia pseudotuberculosis 3. Yersinia pestis

Question 30

Yersinia enterocolitica

Answer 30

causes inflammation of the intestinal tract

Question 31

Yersinia pseudotuberculosis

Answer 31

similar to enterocolitica but less severe

Question 32

Yersinia pestis

Answer 32

causes bubonic and pneumonic plague - nearly 75% mortality rate - killed 1/3 of European population in 14th century

Question 33

Transmission of Y. pestis

Answer 33

1. natural hosts pass on disease to an amplifying 2. either host would make direct contact with a human through biting 3. human would become infected with bubonic plague or pneumonic plague - people with pneumonic plague could pass it as an airborne condition

Question 34

Great fires of London

Answer 34

Destroyed many hay houses and people resorted to bricks. This limited the number of areas for rodent hosts to live.

Question 35

Buboe

Answer 35

- causes by Y. pestis - causes high fever with painful swollen lymph nodes - caused by sub-cutaneous hemorrhaging and death of tissue (gangrene) - death often within a week

Question 36

Why is the bubonic plague also called the black death?

Answer 36

It causes lymph nodes to swell and hemorrhage. This creates blockages in the lymphatic system that hold blood up. Blood eventually begins to turn black causes blackening of the skin.

Question 37

Virulence factors of Y. pestis

Answer 37

1. virulence plasmids confer a Type 3 secretion that inject YopE and YopH which inhibit phagocytosis by degrading actin filaments 2. YopM: inhibits recruitment of additional phagocytes 3. Fra1: glycocalyx capsule makes it harder to engulf 4. Pla: degrades C3b to decrease phagocytosis and C5a so decreased number of phagocytes in area - decreases opsonization and anaphylatoxin

Question 38

Diagnosis of Yersinia pestis

Answer 38

characteristics symptoms - diagnosis and treatment must be rapid to avoid death

Question 39

Treatment of Yersinia pestis

Answer 39

many antimicrobial drugs are effective

Question 40

Bubonic plague

Answer 40

first biological welfare