Common bacterial infections

Question 1

This level of immunity is non-specific ie. has no memory

Answer 1

innate immunity

Question 2

Types of innate immunity

Answer 2

Physical barrier
Phagocytic cells

Question 3

Physical barrier criteria

Answer 3

a. Intact skin
b. Mucous membranes eg. Respiratory tract
c. Blood-brain barrier- tight junctions inhibit entry of organisms
via uninflamed tissues

Question 4

Phagocytic cells criteria

Answer 4

a. Macrophages, Neutrophils, Natural killer cells
b. These cells produce proinflammatory cytokines. Eg. TNF,
IL-1, IL-6
c. Acute phase reactants are produced- eg. CRP

Question 5

Types of adaptive immunity

Answer 5

Active and passive

Question 6

Active vs. passive immunity

Answer 6

Passive immunity- preformed antibodies eg. Breast milk, serum globulin
Active immunity- exposure to an organism via direct exposure or a vaccine

Question 7

B-cells and T-cell funtions

Answer 7

i. B cells produce antibodies- neutralize toxins, lyse bacteria, opsonization of bacteria
ii. T cells- cytotoxic destruction, activates macrophages, help B cells produce antibodies

Question 8

Pathogenic vs. Opportunistic organisms

Answer 8

Pathogenic organism: Those in which cause disease
Opportunistic pathogen: Might cause disease if the conditions are right
Eg. Immunocompromised

Question 9

What is a carrier state?

Answer 9

a person may have an asymptomatic infection, but serve as a reservoir for an infectious organism given to other individuals

Question 10

Mycoplasma have ____, so cannot be classified with a gram stain

Answer 10

no cell wall

Question 11

If bacteria do not have these enzymes, they cannot live in oxygen

Answer 11

superoxide dismutase, peroxidase, and catalase

Question 12

_____ is used in the absence of oxygen to produce ATP.

Answer 12

Fermentation

Question 13

T/F Bacterial species vary in the amounts of oxygen they are able to tolerate

Answer 13

T

Question 14

_____- require oxygen to
grow, and uses the Krebs cycle

Answer 14

Obligate aerobes

Question 15

______- aerobic bacteria that use oxygen if present, but use fermentation if oxygen is not present

Answer 15

Facultative anaerobes

Question 16

_____- thrives in an environment with low oxygen

Answer 16

Microaerophilic

Question 17

______- unable to grow in
the presence of oxygen

Answer 17

Obligate anaerobe

Question 18

_____ - Chlamydia and Rickettsia lack ability to produce ATP

Answer 18

Obligate intracellular

Question 19

Characteristic symptoms of an anaerobic bacteria infection

Answer 19

Foul smelling discharge
Gas in the tissue
Necrotic Tissue

Question 20

Bacteria structure

Answer 20

● unicellular prokaryotic cells measuring about 0.2 to 5 µm.
● Lack a nucleus- single circular DNA strand called a nucleoid
● 70S ribosomes
● Bacterial ribosomes contain a 50S and 30S subunit
● Human cells have 80S ribosomes made up of 60S and 40S subunits
● Lack organelles (eg. Absent mitochondria)
● Cell wall (eg. Human cells have no cell wall)
● May contain plasmids
● Some are motile by means of their flagella
● Some bacteria are spore forming

Question 21

The lipopolysaccharide (LPS) layer of gram negative bacteria is an
_____

Answer 21

endotoxin

Question 22

Mycobacterium (eg. M. tuberculosis) are unique in that they contain layers of _____. These bacteria cannot be gram stained, so an ____ stain is used.

Answer 22

mycolic acid; acid-fast

Question 23

_____ are secreted by both gram positive and gram negative bacteria. These toxins are responsible for the symptoms and unique features of the illness which occur via the multitude of illnesses.

Answer 23

Exotoxins

Question 24

Gram positive bacteria cell wall

Answer 24

2 layers-
● Inner cytoplasmic membrane
● Thick outer peptidoglycan layer
● Teichoic acid

Question 25

Gram negative bacteria cell wall

Answer 25

3 layers ● Inner cytoplasmic membrane ● Periplasmic space ● Very thin middle peptidoglycan layer ● Outer membrane with LPS ● Contains no Teichoic acid

Question 26

Bacteria have multiple _____ which help them colonize, spread, and/or evade the immune system

Answer 26

virulence factors

Question 27

_____- loops of DNA which can replicate separately to the bacterial chromosome

Answer 27

Plasmids

Question 28

____- short strands or filaments that act as adhesins, allowing them to adhere to certain tissue

Answer 28

Pili

Question 29

______- gelatinous covering of the cell, allows resistance to phagocytosis. Responsible for the different serotypes within a bacteria species. This is used for identification of the bacteria and as a target of vaccines. eg. Pneumonia vaccine (PCV), N. meningitidis vaccine

Answer 29

Capsules

Question 30

_____- allows for bacteria to be motile, allowing movement towards a nutrient source

Answer 30

Flagella

Question 31

_____- “glycocalyx” layer allows adherence to surfaces. eg. Skin, teeth (plaque), heart valves (endocarditis), prosthetic joints, catheters. P. aeruginosa is a common problematic species in nosocomial infections. Difficult for antibiotics to penetrate.

Answer 31

Biofilms

Question 32

_____- form in response to adverse conditions ie. reduced nutrients. A keratin like coating is formed which protects the DNA, and the cell from heat, dehydration and chemicals and antibiotics

Answer 32

Spores

Question 33

______- Bacteria produce several types of enzymes that contribute to their pathogenicity. Including increased ability to invade tissues, form clots, deactivate IgA and IgG, and antibiotic resistance. eg. collagenase, hyaluronidase, coagulase, immunoglobulin protease

Answer 33

Enzymes secretion

Question 34

______ - Function as part of the cell wall of gram negative bacteria. Genes lie in the bacterial chromosome itself and are less toxic than exotoxins, but can produce fever and hypotensive shock, leading to septic shock. These toxins bind to receptor surfaces on macrophages

Answer 34

Endotoxins

Question 35

Example categories of exotoxins

Answer 35

● Pyrogenic toxin- cytokine release leading to fever, rash, toxic shock syndrome eg. S. aureus, Strep pyogenes ● Enterotoxin- act on the GI tract leading to infectious diarrhea and/or food poisoning ● Neurotoxin- directed at nerves and their motor end plates leading to paralysis or in certain toxins, causes tetanus

Question 36

_____ are secreted by both fram positive and negative bacteria. Genes can be found on plasmids or bacteriophages. Often have an A (toxicity) and B (binding site) fragments. Extremely toxic

Answer 36

Exotoxins