Gram Negative Pathogens Flashcards Preview

D1S U1 Microbiology > Gram Negative Pathogens > Flashcards

Flashcards in Gram Negative Pathogens Deck (30):
1

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

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

2

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

50-100

3

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

1

4

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

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

5

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

Lysozyme

6

Antimicrobial compound with bacteriostatic effects via sequestering iron

Lactoferrin

7

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

Cathelicidin

8

Antimicrobial compound that creates pores in microbes

Defensins

9

Microbes with _____ tend to be acid resistant.

Low infectious dose

10

Bacterial structures that adhere to tissue to resist being shed

Fimbriae/Pili

11

Recognize microbes via pattern recognition receptors to kill the microbes.

Macrophages

12

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

Inflammatory response

13

The _____ macrophage receptor recognizes LPS on gram negative bacteria

TLR4

14

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

Tight junctions

15

The adaptive immune response is generated in _____

Lymph nodes

16

Invasive Bacteria Pathogens (cause disease by invading intestinal tissue)

1. Salmonella
2. Shigella

17

Shigella spp. Distinguished by O antigen:

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

18

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

Very small

Acid resistance

Colon

19

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

M

Invasion Plasmid antigens

20

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

IcsA

21

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

Ulcer

22

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

Leukocytes

23

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

S. Dysenteriae type 1

24

Two species of Salmonella:

S. Bongori

S. Enterica/Typhimurium (medically important)

25

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

Typhimurium

Enteritidis

26

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

Typhi

Paratyphi

27

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

Pathogenicity islands on large virulence plasmids

28

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

Salmonella Typhi (Typhoid fever)

29

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

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

30

Diagnosis/Treatment of invasive enteric pathogens:

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