Human-Microbe Interactions

Front 1

Microorganisms are normal part of human body. (T/F)

Back 1

True

Front 2

What parts of the body have resident population of microorganisms

Back 2

Mucus membranes lining mouth, gut, excretory, and reproductive tracts

Front 3

Why do humans have microorganisms

Back 3

Beneficial and required to maintain health

Normal flora

Front 4

_____ number of microorganisms can ______ the human body and cause ______

Back 4

Small

Invade
Disease

Front 5

You are what you eat (research)

Back 5

Researchers recruited six men and four women between the ages of 21 and 33. For the first four days of the study, they ate their usually diets. For the next five days, they switched to eating either all plant-based on all animal-based foods. They when went back to their normal eating habitats before switching to the other diet.

The animal-based diet resulted in the biggest changes to gut bacteria. It spurred the growth of 22 species of bacteria, while only three bacterial species become more prominent in the plant-based diet.

Front 6

You are what you eat research publication

Back 6

The research, published Dec. 11 2013 in the journal Nature, showed that the number and kinds of bacteria -- and even the way the bacteria behaved -- changed within a day of switching from a normal diet to eating either animal - or plant-based foods exclusively

Front 7

What does the microbiome affect?

Back 7

Digestion

IBD

Oral disease

Skin infection
Metabolism/weight

Immune system/allergy

CNS development

Behavior/Mental health

Front 8

Define Pathogens

Back 8

Organisms living on or in a host organisms that cause damage are called parasites/pathogens

Front 9

Define pathogenicity of parasite

Back 9

The ability to cause damage to host

Front 10

What does pathogenicity of parasite depend on?

Back 10

Depends on resistance or susceptibility of host to parasite

Front 11

Where do infections frequently begins?

Back 11

mucous membranes

Front 12

Give examples of mucous membranes

Back 12

Mouth, pharynx, esophagus, urogenital, respiratory and gastroinstentinal tracts

Front 13

What does a mucous membrane consist of?

Back 13

Consists of tightly packed epithelial cells at surface

Front 14

What are mucous membranes frequently coated with?

Back 14

Protective layer of soluble glycoproteins - mucus

Front 15

What does a pathogen need to infect something?

Back 15

For a pathogen to infect at a mucosal surface, it needs to adhere to and penetrate the mucus layer (and sometimes the epithelial layer as well)

Front 16

Where are Microorganisms always found where?

Back 16

in regions exposed to environment

Front 17

What are body parts exposed to the environment?

Back 17

Skin, oral cavity, respiratory tract, intestinal tract, and urogenital tract

Front 18

Host-parasite interactions are not found where?

Back 18

Not found in organs, blood, lymph, or nervous system - unless infected! These fluids should be sterile!

Front 19

What does Pathogenesis begin with?

Back 19

Pathogenesis begins with adherence of microorganisms to host cells

Front 20

How do microorganisms invade?

Back 20

Invade through epithelium

Front 21

What follows colonization?

Back 21

Followed by colonization and growth resulting in tissue damage

Front 22

Human-Microbial Interactions (picture)

Back 22

Front 23

Where can infections begin?

Back 23

Infections can begin at breaks or wounds in skin or mucous membranes

Front 24

Infections adhere more strongly to what?

Back 24

to specific host

Front 25

A microorganism that infects humans will often not bind to rat tissue. (T/F)

Back 25

True

Front 26

What do fimbriae and pili bind to?

Back 26

Bind to host glycoproteins on surface, initiating attachment

Front 27

Strains with fimbriae and pili are known to cause what?

Back 27

More infections than strains without

Front 28

Example of organism that uses pili to help infections

Back 28

Neisseria gonorrheae

Pili prevent washing away in the lumen of the uretha

Front 29

Most pathogens must cross the ______ to establish infection

Back 29

Epithelium

Front 30

Some pathogens enter at small lesions. (T/F)

Back 30

True

Front 31

Where can pathogenic growth begin?

Back 31

Growth may begin on intact mucosal surfaces if the normal flora/microbiota has been altered

Front 32

Pathogen growth cannot occur away from the site of entry. (T/F)

Back 32

False. Pathogen growth can occur away from site of entry

Front 33

How can pathogen growth occur away from the site of entry?

Back 33

Move through the blood or lymphatic system

Front 34

Define colonization

Back 34

Organism multiplies after invasion

Front 35

What must an organism have before colonization occurs?

Back 35

Must have right nutrients and environmental conditions

Front 36

Not all nutrients are readily available. (T/F)

Back 36

True

Front 37

What types of nutrients can be limited?

Back 37

Sugars, amino acids, organic acids are limited

Front 38

Not all _____ and _____/_____ available in all tissues

Back 38

vitamins

growth/factors

Front 39

Is Staphylococcus aureus gram positive or negative? what shape?

Back 39

A gram-positive coccus

Front 40

What can Staphylococcus cause on the skin?

Back 40

Can cause a boil

Front 41

Why is S. aureus a growing problem?

Back 41

S. aureus is a growing problem due to resistance to antibiotics... called superbugs

Front 42

Define MRSA strains

Back 42

Methicillin-resistant Staphylococcus aureus

Front 43

What is MRSA resistant to?

Back 43

Resistant to all penicillins

Front 44

Where is MRSA commonly found?

Back 44

Particularly common in hospital-based Staph infections

Front 45

If infections spreads through the blood and lymph system what happens?

Back 45

If spreads through blood and lymph system can cause a systemic infection or (BSI)

Front 46

Define systemic infection

Back 46

Organisms are growing in multiple tissues through the body

Front 47

If bacterial growth in tissues is extensive what happens?

Back 47

Large numbers of organisms will enter the bloodstream

Front 48

What happens when organisms enter the bloodstream?

Back 48

Bacteremia

Almost always starts as a localized infection

Front 49

Define virulence

Back 49

is ability of a parasite to cause disease

Front 50

Define LD50

Back 50

Lethal dose 50

Number of organisms required to kill 50% of animals

Front 51

Pathogens kept in laboratory culture often lose their ______.

Back 51

Virulence

Front 52

What do you call a laboratory culture that lost its virulence?

Back 52

Said to be attenuated

Front 53

Non-virulent mutants may grow _____ - eventually ______ virulent organisms.

Back 53

faster

outgrow

Front 54

What are some attenuated strains for vaccines?

Back 54

Measles and mumps vaccines made from attenuated viruses (MMR vaccine)

Front 55

What are some of the toxins that Salmonelle secretes?

Back 55

Enterotoxin

Endotoxin
Cytotoxin

Front 56

What are factors that help enhance the invasiveness of Salmonella?

Back 56

O antigen, H antigen, fimbriae

Front 57

What are 3 Categories of Exotoxins

Back 57

1. Cytotoxins

2. A-B toxins

3. Superantigens

Front 58

Define Cytotoxins

Back 58

Enzymatically attack cell contituents. Lead to cell death/lysis

Front 59

Define A-B toxins

Back 59

2 covalently bound subunits

B component binds to cell surface receptor

Allows A to be transferred across membrane

Front 60

Define Superantigens

Back 60

Stimulate large numbers of immune response cells: excessive inflammatory reaction

Front 61

What do Cytolytic toxins act on?

Back 61

Act on animal cytoplasmic membrane causes cell lysis

Front 62

What are cytolytic toxins sometimes called?

Back 62

Hemolysins

Front 63

What do hemolysins do?

Back 63

Lyse red blood cells in the laboratory

Create zone of clearing around colonies streaked on blood agar plants

Front 64

Hemolysins _____ cells other too

Back 64

lyse

Front 65

Cytolytic toxins (picture)

Back 65

Front 66

What kind of assay do you use for hemolysins?

Back 66

Blood agar plate assay

Front 67

Blood agar plate assay hemolysis identification

Back 67

Alpha: incomplete

Beta: complete

Gamma: none

Front 68

What produces diphtheria toxin?

Back 68

Corynebacterium diphtheriae

Front 69

In A-B Toxins what does Fragment B do?

Back 69

Fragment B binds to host cell receptor

Front 70

In A-B toxins what does Fragment A do?

Back 70

Is cleaved and enters cells

Front 71

What does A-B Toxins ultimately do?

Back 71

Shuts down protein synthesis

Front 72

Diphtheria toxin is produced by what?

Back 72

Strains of C. diphtheriae that are lysogenized with phage B

Front 73

What carries the toxin encoding gene in diphetheria toxin?

Back 73

phage B

Front 74

Clostridium botulinum is a normal _____ organism

Back 74

Soil

Front 75

Clostridium botulinum grows in the body. (T/F)

Back 75

False. Doesn't grow in the body.

Front 76

Where does Clostridium botulinum grow?

Back 76

Grows in improperly preserved foods

Front 77

Clostridium botulinum is the most potent toxin know. (T/F)

Back 77

True

Front 78

Give examples of how lethal Clostridium botulinum can be

Back 78

1 mg can kill more than 1 million guinea pigs

One gram could kill 14,000 people if swallowed or 8.3 million if injected

Front 79

Botulinum toxin is encoded by what?

Back 79

Lysogenic bacteriophages

Front 80

What is a disease caused by botulinum toxin?

Back 80

Infant botulism

Front 81

What does Botulinum toxin bind to?

Back 81

Binds to presynaptic membranes on termini of stimulatory motor neurons - blocks release of acetylcholine

Front 82

What does Botulinum prevent?

Back 82

prevents muscle contraction - flaccid paralysis

Front 83

How does someone die of Botulinum toxin?

Back 83

Death occurs by respiratory failure and suffocation due to flaccid paralysis

Front 84

Why is Botulinum toxin impractical as a biological weapon?

Back 84

It cannot be absorbed through skin and, unlike anthrax, it is difficult to be inhaled

Front 85

How much Botulinium toxin do you need to kill a million people?

Back 85

A single gram

Front 86

In the 1991 Gulf War, what did Iraq possess?

Back 86

Possessed 19,000 liters of concentrated botulinum toxin - enough to kill the entire human population three times over

In December 1990 the Iraqis had filled 100 R-400 bombs with botulinum toxin, 50 with anthrax, and 16 with aflatoxin. In addition, 13 SCUD warheads were filled with botulinum toxin, 10 with anthrax, and 2 with aflatoxin. These weapons were delopyed in January 1991 to four locations to use against Coalition forces - but were never used...

Front 87

What botulinum called when it is used medically/cosmetically?

Back 87

Botox

Front 88

What are dilute doses of Botulinum toxin effective for?

Back 88

Dilute doses of the toxin are effective for medical uses because they cause only localized muscle relaxation as opposed to total muscle paralysis

Front 89

What the medical uses for dilute botulinum?

Back 89

Dilute botulinum toxin not only relaxes the face muscles that cause wrinkles, but it has also been used to prevent muscle spasms in stroke patients and relax the head and neck muscles that cause migraines

Front 90

Clostridium tetani - normal ______ organism

Back 90

Soil

Front 91

Where does Clostridium tetani grow?

Back 91

Grows in deep puncture wounds - anaerobic environment

Front 92

How is A-B toxin transported?

Back 92

Transported through motor neurons back to spinal cord

Front 93

What does A-B toxin bind to?

Back 93

Binds specifically to ganglioside lipids on inhibitory motor neurons

Front 94

What does A-B toxins prevent?

Back 94

Prevents release of inhibitory signal

Front 95

In A-B toxin infection muscles _____ contracted.

Back 95

Muscle

Front 96

Anthrax in the cold war

Back 96

In another international mystery of the Cold War era, Matt Meselson led a team to Russia in 1992 to determine the cause of a 1979 anthrax epidemic that killed more than 60 people in Sverdlovsk. For years, the Soviets blamed tained meat, which Meselson had described as plausible in Congressional testimony. But he insisted an on-site inquire was needed. Meselson and his wife, medical anthropologist Jeanne Guilleman, were allowed to lead a team to probe the cause of the epidemic. After many interviews with victim's families, it became clear that nearly all of the people who died worked or lived within a long narrow zone downwind of a military microbiological facility suspected of developing biological weapons. With meterological records, Meselson pinpointed the day the germs escaped.

Front 97

What is the Anthrax toxin produced by?

Back 97

Bacillus anthracis

Front 98

Define Enterotoxins

Back 98

A specific exotoxins that act on the small intestine

Front 99

What does Enterotoxins cause?

Back 99

Cause massive secretion of fluid into the intestinal lumen

Front 100

What can enterotoxins lead to?

Back 100

Leads to diarrhea and/or vomiting

Front 101

What is Enterotoxins produced by?

Back 101

A variety of bacteria

Front 102

Name some bacteria that can produce Enterotoxins

Back 102

Staphylococcus aureus, Clostridium perfringens, Bacillus cereus, Vibrio cholerae, E. Coli, Salmonella Enteritidis

Front 103

What is Cholera Toxin produced by?

Back 103

Produced by Vibrio cholerae - causes cholera

Front 104

What kind of toxin is Cholera Toxin?

Back 104

A-B toxin

Front 105

What does the B-subunit in Cholera Toxin bind to?

Back 105

Binds to epithelial lining of small intestine

Front 106

What does the A-subunit in Cholera toxin activate?

Back 106

Activates adenylate cylase

-cAMP produced from ATP

Front 107

Describe the London Cholera Outbreak

Back 107

On August 31, 1854 a cholera outbreak began in the Soho district of London that would ultimately claim over 600 lives

Through a combination of interviews and mapping, physician John Snow was able to pinpoint the source as a water pump on Broad Street (now Broadwick st.)

Snow was able to persuade local officials to restrict public access to the pump by removing the handle; officials later replaced the handle

It was later discovered that the Broad St. well had been dug three feet from an abandoned cesspit

Snow's work is considered the founding event of modern epidemiology

Front 108

How was Cholera Discovered?

Back 108

John Snow and the 1854 outbreak

Identified the source as a public water pump

The first study that used "epidemiology"

Front 109

Stats about Haiti cholera outbreak

Back 109

Since Haiti's cholera outbreak began in October 2010, it has sickened more than 600,000 people and killed more than 8,000

Front 110

What are other enterotoxins similar to cholera?

Back 110

Enteropathogenic E. Coli and Salmonella have enterotoxins similar to cholera toxin

Front 111

Describe the Salmonella outbreak in RI recently

Back 111

Salmonella outbreak tied to Zeppole and other baked goods - March 2011 issued a recall of all backed good from DeFusco's Bakery in Johnston

The 2011 Salmonella outbreak in RI involved 56 cases leading to 26 hospitalizations and one death; infections linked to contaminated pastries

Front 112

The __________ of Gram (-) organisms contain ______ (LPS) - called _____

Back 112

outermembrane

lipopolysaccharide

Endotoxin

Front 113

What does an endotoxin cause?

Back 113

Causes host cells to release endogenous pyrogens - cause fever

Causes death by hemorrhagic shock and tissue necrosis

Front 114

What symptoms can endotoxins cause?

Back 114

fever, diarrhea, decrease in lymphocyte, leukocyte, and platelet number

Front 115

How do endotoxins cause death?

Back 115

By hemorrhagic shock and tissue necrosis

Front 116

In an endotoxin Lipid A portion is _____

Back 116

Toxic

Front 117

In an endotoxin the polysaccharide portion makes it _____ soluble and _____

Back 117

water

immunogenic

Front 118

In Endotoxins both portions are necessary to cause the toxic effect ______/_____

Back 118

in/vivo

Front 119

Very small amounts of LPS will cause reactions in people. (T/F)

Back 119

True

Front 120

What is Menigococcal meninifitis caused by?

Back 120

Cause by the bacterium, Neisseria meningitidis, which causes the most severe form of bacterial meningitis.

Front 121

Define meningitis

Back 121

is an infection of the membranes covering the brain and spinal cord. It can also be found in the blood stream. This particular type of meningitis is very severe and can result in death if not treated promptly. Even in cases where treatment has been given, the fatality rate is around 15%

Front 122

What are the symptoms of meningitis

Back 122

Sudden onset fever, intense headache, nausea and vomiting, and red/purple rash