Mic 201 - Third Midterm

Front 1

What is the term for a microorganism occupying and multiplying in the body?

Back 1

Colonization

Front 2

When does an opportunistic pathogen cause disease?

Back 2

When host defenses are down.

Front 3

What is the term for enhancing virulence in vivo and weakening virulence in vitro?

Back 3

attenuation

Front 4

What are four common portals of entry?

Back 4

Parenteral
Ingestion
Inhalation
Sexual Transmission

Front 5

Punctures, injections, bites, cuts, wounds, etc are examples of what portal of entry?

Back 5

Parenteral

Front 6

What are two common ways that bacterial pathogens cause disease?

Back 6

Bacterial Colonization
Production of toxins.

Front 7

What is ID50?

Back 7

It is the number of microorganisms required to cause infection in 50% of infected animals or humans.

Front 8

What is LD50?

Back 8

Lethal dose to kill half of animals experimentally inoculated.

Front 9

Which organism is more virulent? One that has an LD50 = 2 or LD50 = 20,000

Back 9

LD50 = 2 is more virulent.

Front 10

What are three factors that influence the manifestation of disease in a pathogen-host interaction?

Back 10

Virulence, Infectious dose, and immune status.

Front 11

What is a necessary stem for pathogenicity in bacteria?

Back 11

Adherence

Front 12

What do bacteria use for adherence?

Back 12

Adhesins or ligands located on pilli, fimbriae, flagella, or glycocalyx.

Front 13

Do both Gram positive and Gram negative bacteria have adhesins?

Back 13

Yes

Front 14

What does the binding of a pathogen trigger?

Back 14

Signal Transduction in both host and pathogen.

Front 15

What allows bacteria to resist phagocytosis?

Back 15

Their Capsules, or glycocalyx.

Front 16

In what bacterium does the M protein play a major virulence factor?

Back 16

Streptococcus pyogenes

Front 17

Name some of the bacterial enzymes that allow bacteria combat the immune system.

Back 17

Coagulase, kinase, hyaluronidase, collagenase, IgA protease.

Front 18

How does invasion take place in a bacteria?

Back 18

Invasins allow the rearrangement of cytoskeleton.

Front 19

What trace element is required for growth of most pathogenic bacteria?

Back 19

Iron

Front 20

What are toxins?

Back 20

poisonous substances that damage host cells

Front 21

What are the two pathways of toxins?

Back 21

Excreted directly, or released during bacterial lysis.

Front 22

What is the term that measures a bacterias capacity to produce toxins?

Back 22

Toxigenicity

Front 23

What is the term for toxins transported by the blood?

Back 23

Toxemia

Front 24

In which type of bacteria are exotoxins found? (Gram + or -?)

Back 24

Found in both G+ and G-

Front 25

What are exotoxins?

Back 25

They are toxins directly excreted from the bacteria to the host.

Front 26

How does the body respond to exotoxins?

Back 26

Creates antitoxins to combat these toxins.

Front 27

What type of toxin binds to the host cell surface but do not alter the cell?

Back 27

Type I

Front 28

What type of toxin is an A-B toxin? And which part of the protein has a toxic effect?

Back 28

Type III, the A portion has a toxic effect.

Front 29

What type of toxin acts on cell membranes to cause host cell death?

Back 29

Type II

Front 30

What type of bacteria can produce endotoxins? (G+ or G-)?

Back 30

Gram negative only.

Front 31

What are endotoxins?

Back 31

They are part of the LPS in gram- cell walls. Lipid A is toxic

Front 32

What is pyrogenic?

Back 32

Fever inducing

Front 33

What is shock?

Back 33

It is any life-threatening loss of blood pressure.

Front 34

What is septic shock?

Back 34

It is shock caused by reproducing bacteria in the blood

Front 35

What it it called when high levels of LpS, LTA, or peptidoglycan was found in the blood stream

Back 35

Systemic reaction.

Front 36

What is an acellular infectious agent consisting of nucleic acid enclosed in a protein coat?

Back 36

A virus

Front 37

What is a virus called with no additional covering other than a capsid?

Back 37

A naked virus

Front 38

Where does the viral envelope originate in an enveloped virus?

Back 38

The host cell's nuclear membrane.

Front 39

What are the four different types of viral nucleic acid makeups?

Back 39

Dbl Stranded DNA, dbl stranded RNA, Single Stranded DNA, Single Stranded RNA

Front 40

Do all viruses insert themselves into hosts genome?

Back 40

No

Front 41

Why are viruses considered non-living?

Back 41

They have no cell membrane, no metabolic activity, no ribosomes, and they cannot reproduce on their own.

Front 42

How are viruses classified?

Back 42

Morphology, Type of Nucleic Acid, and Presence of an envelope.

Front 43

Which viral species often cause epidemics/pandemics?

Back 43

Those that "Jump species"

Front 44

What determines the specificity of viruses?

Back 44

Specific attachment receptors and the availability of cellular factors for viral replication.

Front 45

What is the capsid made of?

Back 45

Protein Coat

Front 46

What is the viral envelope made of?

Back 46

Lipid Bilayer w/ proteins and carbohydrates

Front 47

What are spikes made of?

Back 47

Glycoproteins

Front 48

What functions do spikes serve on viruses?

Back 48

Serve to attach virus to specific receptors on host cells.

Also serve for evasion of immune response of host.

Front 49

What are the four basic capsid structures?

Back 49

Helical
Polyhedral
Enveloped
Complex

Front 50

What is an example of a helical virus?

Back 50

Ebola

Front 51

What is an example of a polyhedral virus?

Back 51

Adenovirus

Front 52

What is an example of an enveloped virus?

Back 52

Influenzavirus

Front 53

What is an example of a complex virus?

Back 53

Bacteriophage

Front 54

Parvoviridae, Papovaviridae, Adenoviridae, Herpesviridae, Hepadnaviridae, and poxviridae have which nucleic acid in common?

Back 54

DNA

Front 55

Reoviridae, Retroviridae, orthomyxoviridae, and paramyxoviridae all have what type of Nucleic acid in common?

Back 55

RNA

Front 56

What part of the bacteriophage enters the bacterial cell?

Back 56

Only the nucleic acid.

Front 57

In an animal cell, which part of the virus enters the cell?

Back 57

The whole virus enters by endocytosis or fusion of envelope.

Front 58

What are the five main stages of the viral life cycle?

Back 58

Attachment,
Penetration,
Viral Synthesis,
Assembly and packaging,
Virus release

Front 59

Where does replication usually take place in DNA viruses?

Back 59

In the host nucleus. (Exception is Poxviruses)

Front 60

Where do RNA viruses usually replicate?

Back 60

In the cytoplasms (Except for Influenza Virus)

Front 61

Which type of bacteriophage will lyse the cell after replication?

Back 61

Lytic Phages

Front 62

Which type of bacteriophage will not kill the cell?

Back 62

Lysogenic Phages

Front 63

How are viral plaques formed?

Back 63

They form from the lysed infected bacterial cells.

Front 64

Can lysogenic phages transform into a lytic phage?

Back 64

Yes

Front 65

Can cells be reinfected with the same phage?

Back 65

No

Front 66

What is a prophage?

Back 66

It is the viral DNA incorporated into the hosts chromosome.

Front 67

What two things must a virus replicate for survival?

Back 67

Viral DNA/RNA, and Viral Proteins

Front 68

What is the main difference in animal virus lifestyle with that of the bacteriophage?

Back 68

Uncoating must occur in animal viruses in between penetration and viral synthesis.

Front 69

Which viruses have higher rates of mutation?

Back 69

RNA Viruses

Front 70

Which strand of RNA can host machinery translate?

Back 70

+ strand only

Front 71

What is - strand RNA used for?

Back 71

It serves as the template for the creation of the + strand RNA

Front 72

List the characteristics of the influenza virus.

Back 72

Enveloped, Single Stranded, Segmented, RNA

Front 73

List the characteristics of HIV virus.

Back 73

Enveloped, single stranded, + segmented RNA virus

Front 74

List the characteristics of the Herpes virus.

Back 74

Enveloped, double stranded DNA virus.

Front 75

What are the two surface proteins that the flu virus is named from?

Back 75

Hemaglutinin, and Neuraminidase.

Front 76

Where does RNA replication and mRNA synthesis occur with the Influenza A virus?

Back 76

Nucleus

Front 77

What is the term with the recombination of genes between different viruses?

Back 77

Antigenic Shift

Front 78

What is the term for mutations in viral genome that allow for changes of the antigen?

Back 78

Antigenic drift

Front 79

Who is the natural host for all influenza A viruses?

Back 79

Birds

Front 80

How are viruses grown that are produced for vaccines?

Back 80

In eggs

Front 81

Which enveloped RNA virus reproduces via a DNA intermediate?

Back 81

HIV

Front 82

What are normal genes that if altered can make normal cells cancerous?

Back 82

Proto-oncogenes

Front 83

What is an already altered gene that can produce a protein that can make a cell cancerous?

Back 83

Oncogene

Front 84

What is an oncogenic Virus?

Back 84

A virus that is capable of inducing tumors.

Front 85

What is a prion?

Back 85

It is an incorrectly folded protein that is acquired through contaminated food.

Front 86

Mad cow disease, Creutzfeldt-Jakob disease, sheep and goat scrapie, kuru, Gerstmann-Straussler-Scheinker syndrome and fatal familial insomnia all result from which infectious agent?

Back 86

Prions

Front 87

What is a viroid?

Back 87

A single piece of RNA

Front 88

What is a viroids main host?

Back 88

Plants

Front 89

What is the term for the cause of disease?

Back 89

etiology

Front 90

What baseline is used to determine if a particular pathogen causes a disease?

Back 90

Koch's Postulates

Front 91

What is an exception to Koch's first postulate?

Back 91

Some pathogens are found in both healthy and sick hosts. Like Helicobacter pylori

Front 92

What is an exception to Kochs second postulate?

Back 92

Not all pathogens can be grown in vitro on a pure culture. For example Mycobacterium leprae.

Front 93

What is an endemic disease?

Back 93

A disease that is constantly present.

Front 94

What is the fraction of the population contracting a disease per time period?

Back 94

Incidence

Front 95

What is the fraction of the population having a disease as a specific time?

Back 95

Prevalence

Front 96

What is a subclinical infection?

Back 96

One that does not cause any noticeable illness (carrier)