Micribial Diseases of the Cardiovascular and Lymphatic Systems

Question 1

Name the 2 lymphocytes that foreign microbes encounter when entering the lymph nodes

and their functions

Answer 1

1. B Cells
   
   • • Stimulated to become plasma cells that produce humoral antibodies
2. T Cells
   
   • • Differentiate into effector T cells that are essential to the cell-mediated immune system

Question 2

List the signs and symptoms of sepsis

Answer 2

Fever, chills and accelerated breathing and heart rate.

Sepsis can result in a drop in blood pressure and dysfunction of at least one organ

Question 3

Differentiate Gram (-) sepsis, Gram (+) sepsis and puerperal sepsis

Answer 3

1. Gram (-) Sepsis
   a. Septic shock is most likely caused by Gram (-) bacteria
   b. Endotoxins released by these bacteria when lyzed can cause a severe drop in blood pressure
   c.

Question 4

Differentiate Gram (-) sepsis, Gram (+) sepsis and puerperal sepsis

Answer 4

1. Gram (-) Sepsis
   a. Septic shock is most likely caused by Gram (-) bacteria
   b. Endotoxins released by these bacteria when lyzed can cause a severe drop in blood pressure
   c. See another slide for further info
2. Gram (+) Sepsis
   a.

Question 5

Progression stages of sepsis

Answer 5

a. Sepsis – Release and circulation of Cytokines
b. Severe sepsis
c. Septic shock – when low blood pressure can no longer be controlled by addition of fluids

Question 6

Treatment of Gram (-) sepsis:

a. Why is it uneasy to treat?
b. What drug to use

Answer 6

a. Early symptoms of Gram (-) sepsis are relatively nonspecific and not esp. alarming
b. The progression to lethal stages is rapid and generally impossible to treat effectively
c. The administration of antibiotics at this stage may even aggravate the condition by causing the lysis of large #s of bacteria that will release more endotoxins

d. An effective drug: drotrecogin alfa (Xigris)
- - GM version of human activated protein C, functioning as an anticoagulant to prevent organ damage.

Question 7

What is Lymphangitis?

Answer 7

Inflamed lymph vessels visible as red streaks under the skin, running along the arm or leg from the site of infection, ending at a lymph node
– Often accompanied by Sepsis

Question 8

Treatment of Gram (-) sepsis:

a. Why is it uneasy to treat?
b. What drug to use

Answer 8

a. Early symptoms of Gram (-) sepsis are relatively nonspecific and not esp. alarming
b. The progression to lethal stages is rapid and generally impossible to treat effectively
c. The administration of antibiotics at this stage may even aggravate the condition by causing the lysis of large #s of bacteria that will release more endotoxins

d. An effective drug: drotrecogin alfa (Xigris)
- - GM version of human activated protein C, functioning as an anticoagulant to prevent organ damage.

Question 9

Treatment of Gram (+) sepsis

Answer 9

Use of antibiotics such as Penicillin, vancomycin, etc

Question 10

Explain the cause of Gram (-) Sepsis

Answer 10

Endotoxins released by Gram (-) bacteria when lyzed can cause a severe drop in blood pressure

Question 11

Explain the cause of Gram (+) Sepsis

Answer 11

a. The cause is not known with certain

b. Possible cause: due to various fractions of the Gram (+) cell wall or even bacterial DNA

Question 12

What is endocarditis?

Answer 12

a. An inflammation of the endocardium; a layer lining the heart muscle itself and covers the valves

Question 13

Cause of subacute bacterial endocarditis

Answer 13

1. Caused by alpha-hymolytic streptococci such as are common in the oral cavity
2. Microbes are released by tooth extractions or tonsillectomies, enter the blood, and find their way to the heart

Question 14

Cause of acute bacterial endocarditis

Answer 14

1. Usually caused by S. aureus; released by tooth extractions etc.
2. Penicillin is sometimes used prophylactically to prevent endocarditis during procedures such as tooth extractions and tonsillectomies, but w/ minimal effectiveness

Question 15

Rheumatic fever

Answer 15

1. Autoimmune complications of S. pyogenes infections
2. In about 1/2 of persons affected, an inflammation of the heart, probably from a misdirected immune reaction against Streptococcal M protein, damages the heart valves.

Question 16

Tularemia

Answer 16

1. A zoonotic disease transmitted by contact w/ infected animals, most commonly rabbits and ground squirrels. Best known as rabbit fever
2. Pathogen: Francisella tularensis - Gram (-) bacillus
   3.

Question 17

Brucellosis (undulant fever)

Answer 17

1. Brucella: very small Gram (-) aerobic rods
   – Most common species:
   Brucella abortus (infect livestock, wild elk and bison)
   Brucella suis (infect swine and cattle)
   Brucella melitensis (infect goats, sheep and camels)
2. Symptoms: chills, fever and malaise
   - - Undulant fever: spike to about 40oC each evening
3. Mammals excrete the bacteria in their milk, most commonly transmitted by unpasteurized milk of cattle or goat
4. Once in the body, they are ingested by Macrophages, in which they multiply and travel via the lymphatic system to the lymph nodes; then transported to the liver, spleen or bone marrow.

Question 18

Anthrax

Answer 18

1. Bacillus anthracis, endospore forming bacillus, aerobic, Gram (+)
2. Once in the body, taken up by Macrophages and start to multiply and eventually kill the macrophages.
3. Virulence: due to Two exotoxins.
   a. Edema toxin: causing local edema and interfering w/ phagocytosis by macrophages
   b. Lethal toxin: targeting and killing macrophages
4. Capsule: not polysaccharide but is composed of AA resudues, so immune response is not stimulated
5. Affect humans in 3 forms:
   a. Cutaneous anthrax
   b. GI anthrax
   c. Inhalational anthrax

Question 19

Cutaneous anthrax

Answer 19

1. Results from contact w/ material containing anthrax endospores
2. Endospores enter at some minor skin lesion
3. In most cases, the pathogen does not enter the bloodstream, and other symptoms are limited to a low-grade fever and malaise

Question 20

GI anthrax

Answer 20

1. Caused by ingestion of undercooked food containing anthrax endospores.
2. Symptoms: nausea, abdominal pain and bloody diarrhea. Ulcerative lesions occue in the GI tract ranging from the mouth and throat to the intestines
3. Mortality rate: more than 50%

Question 21

Inhalational (pulmonary) anthrax

Answer 21

1. Most dangerous form of anthrax
2. ENdospores inhaled into the lung and enter the bloodstream
3. Early symptoms: mild fever, coughing and some chest pain. If antibiotics are administered at this stage, the disease can be arrested. Once the bacteria enter the bloodstream and proliferate, the mortality rate is approaching 100%

Question 22

Gangrene

Answer 22

1. Clostridium perfringens: most commonly involved in gangrene
2. Bacteria ferment carbohydrates in the tissue and produce gases that swell the tissue.
3. Enzymes produced by the bacteria degrade collagen and proteinaceous tissue, facilitating the spread of the disease.
4. The surgical removal of necrotic tissue and amputation are the most common medical treatments for gas gangrene.
5. Infected in the abdominal cavity, can be treated in a hyperbaric chamber
6. Penicillin is effective against C. perfringens

Question 23

Lyme disease

Answer 23

1. Cat-scratch disease

2. Pathogen: Bartonella henselae - aerobic, Gram (-)

Question 24

Plague

Answer 24

1. Known as Black Death in the Middle ages - due to dark blue areas of skin caused by hemorrhage
2. Pathogen: Yersinia pestis – Gram (-) rod
3. Disease is transmitted b/w rats by rat flea, Xenopsylla cheopis.
4. From a flea bite, bacteria enter the human’s bloodstream and proliferate in the lymph and blood.
5. If left untreated, mortality rate for bubonic plague is 50-75%
6. Pneumonic plague: mortality rate is 100% (die w/i 3 days)
7. Antibiotics: streptomycin and tetracycline are effective

Question 25

Define bubonic plague, septicemia plague and pneumonic plague

Answer 25

1. Bubonic plague: the lymph nodes in the groin and armpit become enlarged, and fever develops as the body’s defenses react to the infection. Such swellings are called buboes.
2. Septicemia plague: When the bacteria enter the blood and proliferate, causing septic shock
3. When the bacteria are carried by the blood to the lungs, it’s Pneumonic plague

Question 26

Relapsing fever

Answer 26

1. ALL members of the spirochete genus Borrelia, except Bartonella henselae (cause Lyme disease)
2. Transmitted by soft ticks that feed on rodents
3. Symptoms: fever, jaundice, and rose-colored skin spots.

Question 27

Lyme Disease (Lyme Borreliosis)

Answer 27

1. Pathogen: P653

Question 28

Typhus

Answer 28

1. Caused by rickettasias