1/31/17 Mulvey Genetics 2 Pathogenesis TEST #1

Question 1

What are the three mechanisms of Horizontal Gene Transfer?

Answer 1

• Bacterial Transformation
• Bacterial Transduction
• Bacterial Conjugation

Question 2

What is Bacterial Transformation?

Answer 2

-DNA is taken up directly by cells

Question 3

If bacteria are able to take up DNA they are said to be what?

Answer 3

-Competent

Question 4

What are some naturally competent bacteria?

Answer 4

• Bacillus subtilis

- Streptococcus pneumoniae

Question 5

Which strain of Streptococcus pneumoniae is virulent?

Answer 5

-Smooth strain because of capsule

Question 6

What is transduction?

Answer 6

-Transfer of DNA mediated by bacteriophages

Question 7

Where do viruses replicate is Transduction?

Answer 7

-Within bacteria

Question 8

What are the two life cycle phases of the phage?

Answer 8

• Lytic

- Lysogenic

Question 9

What carries important fitness and virulence determinants in the phage life cycle?

Answer 9

-Prophage in the lysogenic cycle

Question 10

What is bacterial conjugation?

Answer 10

-Bacterial sex when one bacteria can make a pilus to grab onto another bacteria

Question 11

What type of plasmid contains tra genes for transfer and are capable of conjugation and result in the expression of sex pili?

Answer 11

-Fertility F-Plasmids

Question 12

What type of plasmid contains genes that code for bacteriocins and some of these are also toxic to host cells?

Answer 12

-Col plasmids

Question 13

What type of plasmid encodes virulence factors and can convert a bacterium into a pathogen?

Answer 13

-Virulence plasmids

Question 14

What type of plasmids contain genes that provide resistance against antibiotics or poisons?

Answer 14

Resistance (R) plasmids

Question 15

What are Transposable elements?

Answer 15

-DNA elements that move from one place in bacterial DNA to another

Question 16

What can transposable elements transfer and disrupt?

Answer 16

-Genes to a new location or disrupt genes when they insert

Question 17

T/F Transposable elements do not carry virulence and antibiotic resistant genes

Answer 17

• False

- They can carry virulence and antibiotic resistant genes

Question 18

How are pathogenicity islands acquired?

Answer 18

-Horizontal Gene Transfer

Question 19

When the host receives goods and services while bacteria may receive shelter, nutrients, transport and other things what is that known as?

Answer 19

-Mutualistic symbiosis

Question 20

What is commensalism?

Answer 20

-Bacteria benefit while host is unaffected

Question 21

What is it known as when damages directly or indirectly affect the host by stimulation of host inflammatory responses?

Answer 21

-Disease

Question 22

What is an organism which, under normal circumstances does not cause disease but can be pathogenic under some conditions?

Answer 22

• Opportunists

- Pathobionts

Question 23

What microbiota is the largest and most studied in the body?

Answer 23

-Gastrointestinal

Question 24

T/F You have increasing number and diversity of microbiota as you descend the GI tract

Answer 24

True

Question 25

T/F Gastrointestinal microbiota helps to extract energy and nutrients from food we eat

Answer 25

True

Question 26

What is colonization resistance?

Answer 26

-Microbiota inhibits colonization by newcomers

Question 27

T/F If you take an antibiotic you can kill some of the bacteria in you gut leaving space for other more pathogenic bacteria to grow.

Answer 27

True

Question 28

Is clostridium difficle gram positive or negative and anaerobic or aerobic?

Answer 28

-Gram positive anaerobe

Question 29

What does clostridium difficile cause pathogenesis?

Answer 29

-Only following antibiotic treatment that depresses the rest of the microbiota of the gut

Question 30

What are two antibiotics that clostridium difficile are associated with?

Answer 30

- Clindamycin | - Fluoroquinolones (Cipro)

Question 31

What are three symptoms of Clostridium difficile and Pseudomembranous colitis?

Answer 31

- Diarrhea - Abdominal pain - Fever

Question 32

What are three reasons that C. difficile can survive antibiotics?

Answer 32

- Resistance genes - Biofilm formation - Spore formation

Question 33

When do clostridium difficile spores form?

Answer 33

- When there is a shortage of nutrients | - Antibiotic treatments

Question 34

What do the spores multilayered protective coat consist of?

Answer 34

- Cell membrane - Thick peptioglycan mesh - Another cell membrane - Wall of Keratin like protein - Exosporium

Question 35

How do you kill spores?

Answer 35

-Autoclaves

Question 36

T/F Most antibiotics, hand sanitizer, isopropanol/ethanol will not kill spores

Answer 36

True

Question 37

What are two medically important spore forming bacteria?

Answer 37

- Clostridium spp | - Bacillus spp.

Question 38

What type of bacteria has nosocomial infections from bacterial spores?

Answer 38

-C. difficile

Question 39

T/F the ability to outcompete commensals at many stages facilitate bacterial infection and survival within a host

Answer 39

True

Question 40

T/F The attachment to host cells and tissues via adhesions increase the odds of not getting a bacterial infection

Answer 40

False | They facilitate bacterial infection and survival

Question 41

What do some bacteria possess that prevent the uptake and destruction by phagocytes?

Answer 41

-Virulence factors

Question 42

T/F Bacteria try to survive in the extracellular environment by having the ability to vary surface exposed antigens that allows outgrowth of antigenically novel clones (antigenic variation, phase shifting).

Answer 42

True

Question 43

What are three ways that bacteria can survive within extracellular environments?

Answer 43

- Capsule - Antigenic variation - Secretion of molecules that interfere with host defenses

Question 44

Is Listeria monocytogenes a gram positive or gram negative anaerobe?

Answer 44

-Gram positive

Question 45

What are toxins?

Answer 45

-Virulence factors that may or may not be excreted that are toxic to human, animal, or plant cells

Question 46

What do toxins cause in the host?

Answer 46

-Aberrant activation of host inflammatory responses

Question 47

What do A-B type toxins include?

Answer 47

-Single chain and multi subunit toxins

Question 48

What can LPS cause?

Answer 48

-Septic Shock

Question 49

Super antigens are what type of toxin?

Answer 49

-Exotoxin

Question 50

What do super antigens bind to?

Answer 50

-MHC class II

Question 51

When the super antigen forms a bridge between the APC and T cells what does that result in?

Answer 51

-Massive outpouring of cytokines

Question 52

What is the most infamous pathogen associated with super antigens?

Answer 52

-Staphylococcus aureus

Question 53

What does staphylococcus aureus cause?

Answer 53

- Food poisoning - Bacteremia/sepsis - Toxic shock syndrome - Abscesses - Cellulitits

Question 54

T/F Together Hospital acquired MRSA and Community acquire MRSA are responsible for more deaths in US than HIV?

Answer 54

True

Question 55

What is the A subunit responsible for in A/B toxins?

Answer 55

-Enzymatic activity

Question 56

What is the B subunit responsible for in A/B toxins?

Answer 56

-Mediates binding to a specific receptor and transfer of the A subunit across the membrane