Principles of Infection

Question 1

define pathogen

Answer 1

microorganisms that cause disease

Question 2

reproduction for bacterial cells

Answer 2

binary fission (grow rapidly until theyve used all the growth resources then they stop growing)

Question 3

define gram stain

Answer 3

a method of staining bacteria for microscopy that allows them to be classified by the structure of their plasma membranes / cell walls

Question 4

how do you perform a gram stain

Answer 4

take some bacteria and fix them on a slide
Then add crystal violet dye, then iodine
Wash with alcohol- some things will retain the purple dye and some wont
Apply a counter stain (safranin) - since some things dont take up the purple stain

Question 5

What type of bacteria stains purple?

Answer 5

gram positive bacteria

Question 6

what type of bacteria stain red?

Answer 6

gram negative bacteria

Question 7

which type of bacteria (gram) has a thick cell wall?

Answer 7

gram positive bacteria

Question 8

which type of bacteria (gram) is harder to treat with antibiotics?

Answer 8

gram negative bacteria

Question 9

cocci bacterial shape

Answer 9

spherical bacteria

Question 10

bacili bacterial shape

Answer 10

rod shaped bacteria

Question 11

spirilla bacterial shaped

Answer 11

spiral

Question 12

vibrio bacterial shaped

Answer 12

curved

Question 13

aerobic bacteria

Answer 13

live in the presence of oxygen

Question 14

anaerobic bacteria

Answer 14

live without oxygen

Question 15

what type of bacteria can live in both environments?

Answer 15

facultative bacteria

Question 16

steps for viral reproduction

Answer 16

Attachment: virus attaches to specific molecules on the cell surface
Once the virus has docked on the attachment protein, it can enter the cell
Penetration: the virus is endocytosed into the cell
Uncoating: the virus’ outer protein coat is removed, exposing the nucleic acid generated
Replication: The nucleic acid captures the cells reproductive mechanisms and replicates its nucleic acids and synthesis new protein coats
Assembly and Release: virus is assembled into a little endosome full of viruses, which go to the cell surface and are then released

Question 17

fluids found on the surface of epithelia contain the bodys natural antibiotics known as?

Answer 17

anti-microbial peptides

Question 18

define innate immunity

Answer 18

non-specific defence system that is against all pathogens

Question 19

type of immunity that involves white blood cells

Answer 19

cell- mediated immunity

Question 20

define anatomical barriers

Answer 20

physical and chemical defences

Question 21

define humoral immunity

Answer 21

involves structures present in body fluids

Question 22

antimicrobial peptides can directly kill microorganisms by?

Answer 22

creating electrostatic interaction (theyre charged), which can rupture bacterial membranes breaking them down or potentially inhibiting their function

Question 23

antimicrobial peptides can either? (function)

Answer 23

directly kill microbes or modulate host immunity

Question 24

how can antimicrobial peptides modulate host immunity?

Answer 24

chemotactic- recruit or activate immunocytes
TLR response- neutralise bacterial products to suppress inflammation
- enhance nucleic acid recognition to promote auto-inflammation

Question 25

where do white blood cells come from?

Answer 25

bone marrow, where we stem cells

Question 26

cells of adaptive immune system

Answer 26

B cells- memory and plasma cell T cells- Helper T cell and cytotoxic T cell

Question 27

Cells of innate immune system

Answer 27

Mast cell, Basophil, Eosinophil, Neutrophil, Macrophage, Dendritic cell, Natural killer cells

Question 28

Examples of Granulocytes

Answer 28

Basophil, Eosinophil, neutrophil

Question 29

Examples of Phagocytes

Answer 29

Neutrophil, Macrophage , dendritic cell, Natural killer cell

Question 30

Define adaptive immune system

Answer 30

Pathogen-specific immune system developed after exposure to pathogen or vaccine

Question 31

Time frame frame for adaptive immunity

Answer 31

Acts slowly over hours to days

Question 32

T cells can either be?

Answer 32

cytotoxic cells - kill the bacteria Helper cells - help cascade the reaction

Question 33

B cells can either be?

Answer 33

Plasma cells - Make the antibodies Memory cells - important in vaccines and our long term resistance to infection

Question 34

Antibodies can neutralise viruses how?

Answer 34

Surround the virus and inactivate it, presenting it from attaching to other healthy cells

Question 35

Define neutralising antibodies

Answer 35

Antibodies that bind to inactivate viruses and toxins

Question 36

antibodies can also recruit things called?

Answer 36

complement

Question 37

Explain the antibacterial property of complement

Answer 37

cascades and escalates the inflammatory process, and also tag bacteria for phagocytosis

Question 38

what activates the complement system and what is triggered?

Answer 38

Antigen - antibody complexes triggering the antibacterial activity

Question 39

Define microbiota

Answer 39

all microorganisms living in and on a human

Question 40

define microbiome

Answer 40

All of the genes of these organisms

Question 41

How can we share our microbiota?

Answer 41

talking, moving, touching, breathing, clothes