Micro 2 Lecture 19

Front 1

Of the Gram + Bacilli, what genera are spore formers?
Of these, which is an obligate anaerobe?

Back 1

Bacillus & Clostridium
Clostridium is an obligate anaerobe

Front 2

Describe the Bacillus genus:

Back 2

Gram +
Catalase +
Endospore forming
Motile
aerobic or facultative anaerobes

Front 3

What is the habitat for the bacillus genus:

Back 3

The primary habitat is the soil

Front 4

Bacillus is a source of:

Back 4

antibiotics

Front 5

two Bacillus species of medical importance are:

Back 5

Bacillus anthracis & Bacillus cereus

Front 6

Are there any anaerobic Bacillus?

Back 6

No, they are either aerobes or facultative anaerobes.

Front 7

All Bacilli are Catalase ___

Back 7

All Bacilli are Catalase +

Front 8

Bacillus are aerobes or facultative anaerobes and Catalase +, while Clostridium are ___________ and Catalase ___.

Back 8

Clostridium are always ANAEROBES and Catalase negative.

Front 9

Many antibiotics that we use came from the genus:

Back 9

Bacillus

Front 10

Describe Bacillus anthracis...
shape:
spore location:
virulence factors:
Habitat:

Back 10

-large, block shaped rods
-spores are in the center of the cell
-virulence factors: Capsule & exotoxins
-lives in the soil

Front 11

The exotoxins that Bacillus anthracis releases cause:

Back 11

cell death or necrosis

Front 12

Describe how one gets infected with Bacillus anthracis:

Back 12

Bacillus anthracis lives in the soil. Spores enter into the human and germinate into a vegetative cells. The vegetative cells produce their exotoxins that cause necrosis.

Front 13

What are the 3 types of anthrax and how they enter the body:

Back 13

Cutaneous anthrax: spores enter through cut or break in the skin.
Pulmonary anthrax: spores are inhaled.
Gastrointestinal anthrax: spores are ingested.

Front 14

The black lesions of tissue necrosis caused by cutaneous anthrax are called:
Are they painful?

Back 14

Eschar lesions; reported as not being very painful.

Front 15

How is Cutaneous anthrax treated?

Back 15

get rid of necrotic tissue and treat aggressively with antibiotics.

Front 16

Can Pulmonary and Gastrointestinal anthrax be treated?

Back 16

They are almost always fatal.

Front 17

Describe what happens when you treat an anthrax patient with antibiotics:

Back 17

The antibiotics kill the vegetative cells, but the exotoxins remain for a few days.

Front 18

Is there an anthrax vaccine?

Back 18

yes, it is given to military, first responders, and animals.

Front 19

Describe Bacillus cereus..
habitat:
how it infects:
virulence factors:

Back 19

-Common in the environment (soil microbe)
-Grows in foods, spores and toxins survive cooking & reheating
-Enterotoxins cause food intoxication.

Front 20

Enterotoxins are ____ toxins that cause __________.

Back 20

Enterotoxins are EXOTOXINS that cause GASTROENTERITIS.

Front 21

What is relatively unusual about Bacillus cereus food intoxication events?

Back 21

That B. cereus likes to infect rice and potato dishes which is rare. Also infects meat though.

Front 22

Describe the Clostridium genus:

Back 22

-Ovoid, Terminal spores (spores form at the end as opposed to the center)
-Gram +
-Catalase Neg.
-Anaerobic

Front 23

Describe the habitat of the Clostridium genus:

Back 23

Found in the soil, some are commensals.

Front 24

Commensal means?

Back 24

that the bacteria is a part of the natural flora of some organism.

Front 25

Can Clostridium spores germinate in the presents of oxygen?

Back 25

No, they will only germinate in anaerobic conditions.

Front 26

What kinds of infections does Clostridium usually cause?

Back 26

Wound infections
Tissue infections
Food intoxication

Front 27

What are some Clostridium species of medical importance?

Back 27

-Clostridium perfringens (causes gangrene)
-Clostridium difficile (causes gastroenteritis)
-Clostridium tetani (causes tetanus)
-Clostridium botulinum (causes botulism)

Front 28

Describe Clostridium perfringens infection process, what toxins are released?

Back 28

spore from the soil enters through a wound. The spores only germinate in anaerobic wounds. Vegetative cells release gas & alpha toxin.

Front 29

What does alpha toxin do?

Back 29

alpha toxin causes tissue necrosis and also kills RBCs.

Front 30

Gangrene is painful because:

Back 30

the gas forces tissue cells apart.

Front 31

Describe the treatment of Clostridium perfringens:

Back 31

get rid of necrotic tissue and treat aggressively with antibiotics. Hyperbaric chamber can also be used because he is an anaerobe.

Front 32

Describe Clostridium difficile habitat:

Back 32

-Normal resident of human colon, in low numbers.

Front 33

What does Clostridium difficile cause?

Back 33

anti-biotic associated colitis

Front 34

Describe an infection by Clostridium difficile:

Back 34

Clostridium difficile is a normal resident of the human colon in low numbers. Anti-biotic treatment can cause a superinfection. In high numbers, he begins to release enterotoxins that first cause gastroenteritis, but can then cause necrotic lesions to form. These lesions can then lead to perforations in the bowels.

Front 35

If a broad spectrum anti-biotic is used, one of the most likely of the gut bacteria to survive would be:

Back 35

Clostridium difficile because he can form spores.

Front 36

Who is at most risk for Clostridium difficile infection?

Back 36

Nursing home patients

Front 37

Describe Clostridium tetani reservoir:

Back 37

-Common resident of soil & animal GI tracts

Front 38

Describe tetanus infection:

Back 38

Clostridium tetani spores enter through a puncture wound and germinate in anaerobic tissue. The vegetative cells begin to release an exotoxin that blocks muscle relaxation.

Front 39

The exotoxin released by Clostridium tetani is called:

Back 39

Tetanospasmin toxin

Front 40

Tetanus is most common around the world in:

Back 40

Newborns

Front 41

How do all these newborns end up with tetanus?

Back 41

It is common in many places to treat the umbilical stump with something; dirt, dung, etc. which can contain Clostridium tetani of course.

Front 42

The death rate for tetanus even with treatment is:

Back 42

50%

Front 43

The tetanus vaccine is called:

Back 43

the TDaP; which is a Tetanus toxoid vaccine

Front 44

Describe Clostridium botulinum reservoir:

Back 44

Common in soil & animal's GI tract

Front 45

The exotoxin released by Clostridium botulinum is called:

Back 45

botulinum toxin

Front 46

What does the botulinum toxin do?

Back 46

it causes flaccid paralysis by blocking ACh release. Thus, muscles never receive signal from nerves and cannot contract.

Front 47

What are the three types of infection with Clostridium botulinum?

Back 47

-food poisoning
-infant botulism
-wound botulism

Front 48

The most common form of infection from botulism is:

Back 48

food poisoning from improper canning techniques.

Front 49

Describe how food poisoning from Clostridium botulinum occurs:

Back 49

improper canning techniques fail to kill the Clostridium botulinum spores. The anaerobic environment inside the canned goods is perfect for the vegetative cells. They then produce the botulinum toxin.

Front 50

What is the most potent toxin known to man?

Back 50

the botulinum toxin.

Front 51

Describe infant botulism:

Back 51

Infant ingests spores that germinate and release botulinum toxin. Infants lack the immune system and flora needed to protect them. Botulism is not harmful if ingested by adults.

Front 52

Infant botulism is also called:

Back 52

floppy baby syndrome

Front 53

Describe the Clostridium botulinum infection caused by entering through a wound:

Back 53

Clostridium botulinum spores enter through a puncture wound and and germinate in the anaerobic environment. The Vegetative cells then release botulinum toxin.

Front 54

What is Botox?

Back 54

it is an inactivated form of the botulinum toxin that is diluted.

Front 55

The spore forming Bacilli are:

Back 55

Bacillus and Clostridium

Front 56

How do Bacillus and Clostridium differ?

Back 56

Bacillus are aerobes or facultative anaerobes and Catalase +
Clostridium are strict anaerobes and Catalase ⊝

Front 57

Describe Listeria monocytogenes..
morphology:
Spores?
reservoir:

Back 57

-Gram +, regular shaped bacilli
-Non-spore forming
-Primary reservoir is soil & water

Front 58

Describe the heartiness of Listeria monocytogenes:

Back 58

Resistant to cold, heat, salt, pH extremes, and bile

Front 59

Describe Listeria monocytogenes infection:

Back 59

infection results in food poisoning particularly after refrigeration of dairy products, poultry, & meats.

Front 60

Listeria monocytogenes infection is called:

Back 60

Listeriosis

Front 61

How does a Listeria monocytogenes infection affect animals?

Back 61

it causes still births

Front 62

Listeria has been associated particularly with the consumption of:

Back 62

unpasteurized dairy products

Front 63

Can Listeria monocytogenes grow in the fridge?

Back 63

yes, it grows well in the fridge.

Front 64

Besides, unpasteurized dairy products, what else has Listeria monocytogenes been particularly associated?

Back 64

Processed Deli meats: cold cuts

Front 65

Describe Corynebacterium diptheriae:

Back 65

-Gram +, irregular shaped Bacilli (dogbone, or pleomorphic)

Front 66

Corynebacterium diphtheriae causes a disease called:

Back 66

diphtheria

Front 67

The diphtheria infection is transmitted through:
It is now thought to also be transmitted through:

Back 67

airborne droplets exhaled from host and inhaled by subject.

through infected milk.

Front 68

What are the two stages of diphtheria?

Back 68

Local infection & systemic infection

Front 69

Describe the local diphtheria infection:
Symptoms?

Back 69

The local diphtheria infection causes an Upper respiratory tract infection. The symptoms are: sore throat, swollen lymph nodes, fever and pseudomembrane formation.

Front 70

Describe the pseudomembrane caused by the local diphtheria infection:

Back 70

a thick, gray, leathery membrane on the back of the tongue that can grow large enough to cause asphyxiation. Is very hard to remove.

Front 71

Describe why Corynebacterium diphtheriae causes a systemic infection:

Back 71

Corynebacterium diphtheriae only causes a systemic infection when he has been infected by a bacteriaphage.

Front 72

Describe the Corynebacterium diphtheriae systemic infection:
Toxins?

Back 72

If a patient is infected with Corynebacterium diphtheriae that has been infected by a bacteriaphage, he produces diphtherotoxin. The diphtherotoxin enters the blood stream causing toxemia and damage to multiple organs, usually the heart and nerves which can be deadly.

Front 73

Describe the Mycobacterium genus:

Back 73

-Gram +, irregular Bacilli
-Acid-fast (has mycolic acid)
-often long and filamentous
-Strict aerobes
-Grow slowly

Front 74

Two medically important species in the Mycobacterium genus are:

Back 74

Mycobacterium tuberculosis & Mycobacterium leprae

Front 75

Describe Mycobacterium tuberculosis:
Transmission:
Growth:
Virulence factors:

Back 75

-Transmitted by fine, airborne respiratory droplets
-Grows in characteristic "chords"
-Produces no exotoxins or enzymes as virulence factors.
-Contains complex waxes & chord factors

Front 76

If you inhale airborne droplets with Mycobacterium tuberculosis, you get ___________ tuberculosis.

Back 76

If you inhale airborne droplets with Mycobacterium tuberculosis, you get PRIMARY tuberculosis.

Front 77

Describe the Mycobacterium tuberculosis infection process:

Back 77

Bacteria is inhaled in airborne droplets. Alveolar macrophages phagocytize the bacterial cells, but are not able to kill it. Mycobacterium tuberculosis grows inside the macrophages. Weeks later, other immune cells respond and surround the alveolar macrophage that contains the living Mycobacterium tuberculosis cell forming a tubercle.

Front 78

What is a tubercle?

Back 78

A mass of immune cells surrounding & attacking the infected macrophage.

Front 79

Describe secondary tuberculosis:

Back 79

Tubercles expand and produce inflammatory fluid which drains into the bronchial tubes & upper respiratory tract. Gradually the patient experiences more severe symptoms.

Front 80

What are the symptoms of secondary tuberculosis?

Back 80

Chills & sputum production

Front 81

Describe Extrapulmonary TB:

Back 81

Sometimes, during secondary TB, the Bacilli begin to spread to other areas of the body. Usually the kidneys, bones, brain, or genitals. Very high mortality rate.

Front 82

Recap the stages of TB:

Back 82

Primary TB: Bacteria is inhaled, macrophages ingest it but can't kill it. Tubercles form around macrophages.
Secondary TB: Tubercles expand and release inflammatory fluids.
Extrapulmonary TB: Bacilli spread to other areas of the body. Very high mortality rate.

Front 83

What stage do symptoms of TB begin to appear?

Back 83

Secondary TB.

Front 84

Mycobacterium Leprae is also called:

Back 84

Hansen's Bacillus

Front 85

Describe Mycobacterium Leprae:

Back 85

-Not very contagious
-Strict parasite: (never been grown on artificial media or tissue cultures)
-slowest growing of all species
-multiplies inside of host cells

Front 86

What are the only two reservoirs that Mycobacterium Leprae grows?

Back 86

Humans & the footpads of armadillos

Front 87

Mycobacterium Leprae causes the disease:

Back 87

Leprosy

Front 88

Describe Leprosy..
Prevalence:
Transmission:

Back 88

-Endemic to regions throughout the world
-Spread through direct contact (but not very contagious)

Front 89

Describe the infection process of Leprosy:

Back 89

Once infected, Mycobacterium Leprae will multiply in the macrophages in the skin and spread to the nerves.

Front 90

Are most patients symptomatic?

Back 90

No, most patients clear the infection without ever showing symptoms. Others clear the infection after showing symptoms.

Front 91

What are the two different forms of Leprosy?

Back 91

Tuberculoid & Lepromatous

Front 92

Describe Tuberculoid Leprosy:

Back 92

Tuberculoid Leprosy is a superficial infection without skin disfigurement. It damages nerves and results in a loss of pain perception.

Front 93

Describe the temperature relationship between Mycobacterium Leprae and the human body:

Back 93

Mycobacterium Leprae prefers a temperature that is slightly cooler than the human body, so he grows in the cooler spots of the human body. He likes the nerves because they are cooler than the rest of the body.

Front 94

Describe Lepromatous Leprosy:

Back 94

Nodular infections that cause severe disfigurement of the face & extremities. Nodules can block circulation and cause the loss of the tips of fingers and nose.