Chapter 14: Host-microbe Disease Relationship and Disease Process

Question 1

Mutualism

Answer 1

Both organisms benefit

Question 2

Parasitism

Answer 2

One benefits, one is negatively impacted

Question 3

Commensalism

Answer 3

One is benefitted, one isn’t impacted

Question 4

Host invasion

Answer 4

Contamination: microbes are present
Infection: microbes multiply
Disease: microbes causes disruption of host function/health

Question 5

Pathogenicity

Answer 5

Capacity to cause disease

Question 6

Virulence

Answer 6

Intensity/ strength of disease

Question 7

Virulence factors

Answer 7

Physical feature or chemical produced by microbes that increases strength of disease

Question 8

Attenuation

Answer 8

Weakening of pathogen so it is no longer harmful or causes disease, but still capable of causing an immune response (idea behind vaccines)

Question 9

Resident microflora

Answer 9

Always present

Question 10

Transient microflora

Answer 10

Temporary

Question 11

Sterile body sites

Answer 11

Internal tissues and organs: 
- middle ear
- sinuses
- internal eye
- bone marrow
- muscles
- glands
- organs
- circulatory system
- brain and spinal cord
- ovaries and testes 
Body fluids: 
- blood
- cerebrospinal fluid
- saliva prior to secretion
- urine in kidneys and bladder
- semen prior to entry into urethra

Question 12

Opportunism

Answer 12

Microbes can cause infection if given the right conditions

• host defense failure (immunocompromised)
• microbes introduced to unusual locations
• microflora disturbances

Question 13

Infectious diseases

Answer 13

Caused by infectious agent

- bacteria, virus

Question 14

Non infectious disease

Answer 14

Caused by other sources like mutations

Question 15

Communicable disease

Answer 15

Contagious

Question 16

Non communicable

Answer 16

Not contagious

- ear infection

Question 17

Contagious

Answer 17

Easily spread

Infectious + communicable

Question 18

Disease process

Answer 18

1. Enter the host
2. Attach to host cell
3. Grow/colonize/multiply in host
4. Disrupt host health, may produce enzymes/toxins or invade tissues
5. Evade host immune system

Question 19

Adherence factor

Answer 19

Attachment polo, Fimbrae, glycocalyx

Question 20

Enzymes as virulence factors

Answer 20

Microbes may release damaging enzymes

• coagulase causes a clot around bacteria, streptokinase dissolved the clot
• hyaluronidase dissolves “glue” between cells

Question 21

Toxins

Answer 21

Poisonous substances that are categorized by how they’re released from the cell

Question 22

Endotoxins

Answer 22

Exist inside microbial cell, can cause fever, shock, possible host death
- G- bacteria have LPS in cell membrane (toxin released when cell dies)

Question 23

Exotoxins

Answer 23

Made to be secreted, very potent, usually proteins, often cause damage to specific tissues
- G+

Question 24

Leukocidin

Answer 24

Exotoxins that targets WBCs

Question 25

Hemolysins

Answer 25

Exotoxins that target RBCs

Question 26

Neurotoxins

Answer 26

Exotoxins that target nervous tissue

- very serious, often fatal ex. Botulism

Question 27

Enterotoxins

Answer 27

Exotoxins that target gut bacteria

- usually food poisoning

Question 28

Toxoid

Answer 28

Toxin that’s been neutralized so that it doesn’t cause disease but will mount an immune response
- tetanus vaccine

Question 29

Sign

Answer 29

Characteristic of a disease that can be observed by examining the patient

Question 30

Symptom

Answer 30

Characteristic of disease that can be observed or felt only by the patient

Question 31

Syndrome

Answer 31

Combination of signs and symptoms that occur together and are indicative of a particular disease or abnormal condition

Question 32

Sequelae

Answer 32

After effects of disease

Question 33

Acute disease

Answer 33

Develops rapidly and runs its course quickly

- measles and colds

Question 34

Chronic disease

Answer 34

Develops more slowly and is usually less severe, persists for a long indeterminate period
- tuberculosis and leprosy

Question 35

Subacute disease

Answer 35

Intermediate between acute and chronic

- gingivitis

Question 36

Patent disease

Answer 36

Periods of inactivity before signs and symptoms or between attacks
- herpes simplex

Question 37

Local infection

Answer 37

Confined to a specific area of the body

- boils, bladder infections

Question 38

Systemic infections

Answer 38

Affects most of the body & pathogens are widely distributed in many tissues
- typhoid fever

Question 39

Bacteriemia

Answer 39

Bacteria in the blood

Question 40

Viremia

Answer 40

Viruses in the blood

Question 41

Primary infection

Answer 41

Initial infection in a previously healthy person

- usually acute

Question 42

Secondary infection

Answer 42

Follows primary, especially in individuals weakened by primary infection
- someone weakened by cold (primary) may then get a middle ear infection (secondary)

Question 43

Superinfection

Answer 43

Secondary infection that results from the destruction of normal microflora and often follows the use of broad spectrum antibiotics

Question 44

Disease stages

Answer 44

Incubation: time between infection and appearance of signs and symptoms
Prodromal: short period where nonspecific, mild symptoms (headache) appear
Invasive: period where typical signs and symptoms are felt, disease is at acme
Decline: immune system and treatment overcome pathogen, microbes numbers drop, feel better
Convalescence: healing from tissue damage, body gains strength