1.1 Introduction

Question 1

microorganisms are present in the environment and can cause contamination

Answer 1

germ theory of disease

Question 2

Koch’s postulates:

• organism is ________ in the lesions of the disease
• organism can be __________ on artificial media
• inoculation of this pure culture produces __________ in experimental animals
• organism can be ________ from the lesions in these animals

Answer 2

• regularly found
• isolated in pure culture
• similar disease
• recovered

Question 3

the 5 types of infectious agents?

Answer 3

1. prions
2. viruses (acellular)
3. bacteria (prokaryotic)
4. fungi (eukaryotic)
5. parasites (eukaryotic)

Question 4

• have primitive nucleus
• bacteria
• small (1 micron in diameter)
• rigid peptidoglycan cell wall

Answer 4

prokaryotes

Question 5

• have true nucleus
• protozoa, fungi, plants, animals
• 5-30 microns in diameter
• evolved from fusion of prokaryotic cells
• membrane bound organelles (nucleus and mitochondria/chloroplasts contain DNA)
• animal cells lack cell wall, fungal and plant cell walls are chemically different

Answer 5

eukaryotic

Question 6

bacterial species must have greater than ________ % identity in 16S rRNA, isolates share many characteristics

Answer 6

97

Question 7

Linnean binomial system is ______ first then _______

Answer 7

genus, species

Question 8

microorganism in symbiotic relationship with host

Answer 8

commensal

Question 9

ability of a microorganism to persist and multiply

Answer 9

colonization

Question 10

colonization with commensal microorganisms

Answer 10

normal flora

Question 11

microorganism that can cause disease

Answer 11

pathogen

Question 12

degree of pathogenicity

Answer 12

virulence

Question 13

colonization by a pathogen

Answer 13

infection

Question 14

result of infectious process leading to host damage

Answer 14

disease

Question 15

factors and mechanisms of disease spread

Answer 15

epidemiology

Question 16

limited to small number of isolated cases (meningitis, relapsing fever)

Answer 16

sporadic

Question 17

continually prevailing in a region (malaria)

Answer 17

endemic

Question 18

outbreak (listeriosis, salmanellosis)

Answer 18

epidemic

Question 19

a worldwide outbreak (cholera, HIV/AIDS)

Answer 19

pandemic

Question 20

from acquisition of microorganism to disease onset

Answer 20

incubation period

Question 21

nonspecific symptoms

Answer 21

prodrome

Question 22

characteristics of clinical manifestations

Answer 22

specific illness

Question 23

after resolution of symptoms to complete recovery, there can be complications such as chronic carriers, latent infections, permanent tissue damage after elimination of pathogen

Answer 23

convalescence

Question 24

the number of microorganisms needed to infect 50% of host population

Answer 24

infectious dose, ID50

Question 25

number of microorganisms needed to kill 50% of host population

Answer 25

lethal dose, LD50

Question 26

virulence is _______ proportional to ID/LD

Answer 26

inversely

Question 27

portals of entry?

Answer 27

skin, soft tissue (trauma_

• skin, bloodstream (arthropod bite)
• respiratory (inhalation)
• GI (ingestion)
• genital (Sexual transmission)
• transplacental

Question 28

hand hygience, procedure appropriate PPEs (gloves, gowns, masks, etc)

Answer 28

standard precautions

Question 29

gloves and gowns, private rooms (diarrhea due to C diff or norovirus)

Answer 29

contact precautions (direct or indirect)

Question 30

masks/respirators for staff/patient, closed room, for influenze or N meningitidis

Answer 30

direct precautions (<3 ft)

Question 31

N95/PAPR respirators, airborne infection, isolation room, ex measles or M tuberculosis

Answer 31

airborne precautions (>3ft)

Question 32

airborne + contact + eye protection, ex SARS, avian/pandemic influenza

Answer 32

full barrier precautions