Gram Negative Pathogens

Question 1

7 F’s of fecal transmission to mouth (gram negative mucosal pathogens):

Answer 1

1. Feces
2. Food
3. Fluids
4. Fingers
5. Flies
6. Fomites
7. Fornication

Question 2

For some bacteria, as few as ____ organisms is enough to cause disease. For other bacteria, millions of organisms are needed.

Answer 2

50-100

Question 3

There is only ____ layer(s) of epithelial cells separating the interior of the body from billions of microbes on mucosal surfaces.

Answer 3

1

Question 4

Natural anatomical/physiological properties that create physical barrier to microbes:

Answer 4

1. Acidity
2. Motility
3. Mucous layer and underlying glycocalyx
4. Tight junctions

Question 5

Secretory antimicrobial compound that cleaves beta 1,4-glycosidic linkages between NAN and NAG

Answer 5

Lysozyme

Question 6

Antimicrobial compound with bacteriostatic effects via sequestering iron

Answer 6

Lactoferrin

Question 7

Antimicrobial compound that disrupts bacterial membranes of Gram neg and positive (and fungi)

Answer 7

Cathelicidin

Question 8

Antimicrobial compound that creates pores in microbes

Answer 8

Defensins

Question 9

Microbes with _____ tend to be acid resistant.

Answer 9

Low infectious dose

Question 10

Bacterial structures that adhere to tissue to resist being shed

Answer 10

Fimbriae/Pili

Question 11

Recognize microbes via pattern recognition receptors to kill the microbes.

Answer 11

Macrophages

Question 12

Activation of pattern recognition receptors on macrophages also initiates the ______.

Answer 12

Inflammatory response

Question 13

The _____ macrophage receptor recognizes LPS on gram negative bacteria

Answer 13

TLR4

Question 14

Inflammatory cytokines like TNF-alpha can disrupt the _____ of epithelial cells (negative effect of mucosal inflammatory response to bacteria)

Answer 14

Tight junctions

Question 15

The adaptive immune response is generated in _____

Answer 15

Lymph nodes

Question 16

Invasive Bacteria Pathogens (cause disease by invading intestinal tissue)

Answer 16

1. Salmonella

2. Shigella

Question 17

Shigella spp. Distinguished by O antigen:

Answer 17

1. S. Dysenteriae
2. S. Flexneri
3. S. Boydii
4. S. Sonnei

Question 18

Shigella inoculum size is ____. Survives stomach by _____. Will multiply/colonize the ____.

Answer 18

Very small

Acid resistance

Colon

Question 19

Shigella enter ____ cells (phagocytic cells) via outer membrane proteins called _____ to reach the basal surface of the intestinal epithelium and infect it.

Answer 19

M

Invasion Plasmid antigens

Question 20

Intracellular spread of Shigella is facilitated by ____, an ATPase that causes actin polymerization.

Answer 20

IcsA

Question 21

This develops in the digestive system when invaded cells die and slough off. (From Shigella producing toxins)

Answer 21

Ulcer

Question 22

All bacterial species will induce an inflammatory diarrhea with ____ in the stool.

Answer 22

Leukocytes

Question 23

Causes invasive diarrhea and produces shiga toxin (kills intestinal cells, disrupts Na absorption).

Answer 23

S. Dysenteriae type 1

Question 24

Two species of Salmonella:

Answer 24

S. Bongori

S. Enterica/Typhimurium (medically important)

Question 25

Gastroenteritis is caused by Salmonella _____ and S. ____ serotypes.

Answer 25

Typhimurium Enteritidis

Question 26

Typhoid fever is caused by S. ____ and S. _____ serotypes

Answer 26

Typhi Paratyphi

Question 27

Low pH induces the expression of at least 40 proteins found on _____ of Salmonella

Answer 27

Pathogenicity islands on large virulence plasmids

Question 28

Enters into lymphatic system and replicates within macrophages throughout the body. Strictly a human pathogen. Asymptomatic carriers (colonized gall bladders).

Answer 28

Salmonella Typhi (Typhoid fever)

Question 29

Similarities and Differences between invasive enteric pathogens (Salmonella and Shigella)

Answer 29

Similarities: 1. Invasive 2. Respond to environmental changes Differences: 1. Inoculum size (acid sensitivity) 2. Bacteremia (Salmonella) 3. Species that cause severe disease very different

Question 30

Diagnosis/Treatment of invasive enteric pathogens:

Answer 30

1. Based on symptoms/stool 2. Oral rehydration 3. Antibiotics 4. Fluoroquinolones or surgical removal of gallbladder, Vaccine. (For Typhoid fever)