Module 5

Question 1

transient microorganisms

Answer 1

pass through host without causing harm or establishing residence

Question 2

commensal

Answer 2

established residency in host but do not cause harm, may be beneficial
- normal flora

Question 3

physical and mechanical barriers of host

Answer 3

epithelial cells

• skin: inhabits bacterial and fungal growth
• Gi/GU: mucous membranes trap microorganisms and remove them
• respiratory tract: mucociliary system sweeps organisms up and out

Question 4

biochemical barriers of host

Answer 4

acidic environment
acid in stomach
antimicrobial chemcials

Question 5

impaired immune system can be due to

Answer 5

immunosuppressive drugs
inflammatory disorders
poor nutrition
young or old age
chronic illness

Question 6

Pathogen characteristics

Answer 6

adherence and invasion
bacterial endotoxin
bacterial exotoxin
evasion of immune cells 
antimicrobial resistance

Question 7

Endotoxin

Answer 7

in cell well, gram negative. lipopolysaccharides released when cell is destroyed.

Question 8

exotoxin

Answer 8

toxin secreted by bacteria, gram positive

released during bacterial growth

Question 9

evasion of immune cells

Answer 9

coating on surface prevents phagocytosis

biofilm: bacteria uses host to create capsule and hide.

Question 10

bacteria

Answer 10

singe-celled, rigid-walled organisms with no internal organs

Question 11

shapes of bacteria

Answer 11

cocci: spherical (clusters, chains, pairs, tetrads)
bacilli: rod shaped
spiral

Question 12

sprochetes

Answer 12

bacteria that possess motile spiral filament

Question 13

mycoplasma

Answer 13

smallest bacteria, no rigid wall and pleomorphic

Question 14

Rickettsia:

Answer 14

intracellular parasites with variety of shape

Question 15

chlamydia

Answer 15

intracellular parasite with complex life cycle

Question 16

gram positive

Answer 16

thick cell wall, peptidoglycan layer. stains purple

Question 17

gram negative

Answer 17

thin cell wall

Question 18

nutritional requirements of bacteria

Answer 18

anaerobic

aerobic

Question 19

colonization of bacteria

Answer 19

require adhesion: limits sites where bacteria can colonize.

Question 20

fungi

Answer 20

eukaryotic microorganisms with complex structures and thick, rigid cells walls. Do have organelles.

Question 21

dermatophytes

Answer 21

fungi in skin, hair, and nails

Question 22

deep fungal infections

Answer 22

life threatening due to similar make up to host cells. Medications also kill host cells.

Question 23

parasites

Answer 23

range from small unicellular protozoan to large worms.

Question 24

4 families of parasites

Answer 24

protozoa: single celled
nemathelminths: round worms
platyhelminths: flat worms
arthropoda: invertebrate with jointed appendages.

Question 25

parasite transmission

Answer 25

vector

• mosquitoes
• water/food
• oral

Question 26

viruses

Answer 26

smalles infectie angents
consist of:
- protein shell: capsid
- core genetic material (RNA or DNA)
- some have protective envelope encircling capsid

Question 27

classification of viruses

Answer 27

DNA or RNA
Double or single stranded
Retrovirus: contains enzyme reverse transcriptase

Question 28

reverse transcriptase

Answer 28

converts RNA to DNA

Question 29

obligate intracellular parasite

Answer 29

viruses require host

Question 30

zoonotic

Answer 30

animal reservoir of virus

Question 31

CCR5- delta 32 gene

Answer 31

natural immunity to HIV, especially with both genes mutated

Question 32

chain of transmission of microorganism

Answer 32

Reservoir: human animal insect soil
Portal of exit: nasal mucosa, oral mucosa
Mode of transmission: insect bite, nasal droplets, semen
Portal of entry: nasal mucosa, oral mucosa, skin abrasion, skin puncture, sex
Susceptible victim: malnourished, unimmunized, immune compromised.

Question 33

bacteria classified by (2) and then further differentiated by (3)

Answer 33

morphology and gram staining

nutritional requirements, colony characteristics, resistance patterns

Question 34

HIV p24 contains 2(blank) and 3 enzymes

Answer 34

RNA
protease
integrase
reverse transcriptase

Question 35

gp120 and gp41

Answer 35

Have similar characteristics to MHC, immune system does not recognize them.

Question 36

pediatric Dx of HIV

Answer 36

personal hx, viral culture, clinical manifestations.

- CNS is particularly vulnerable: developmental delays, impaired brain growth, motor deficits.