Microbiology Lecture 32: Host Parasite Relationships

Front 1

Humans have a lot of normal microflora.

The human body has BLANK cells and is comprised of BLANK microbes.

Normal flora consists of BLANK flora, more or less constant, and BLANK flora, which inhabit a specific spot for a short period of time.

Back 1

10^13; 10^14

resident; transient

Front 2

Antagonism of biocontrol are the basis of what?

This is how bacteria that are part of the “normal flora” provide the host with protection against potentially BLANK BLANK.

Probiotics are microorganisms in BLANK or BLANK that help stimulate the BLANK BLANK. It is an example of BLANK.

Back 2

Probiotics

pathogenic bacteria

dairy or yogurt; immune system; biocontrol

Front 3

Name examples of antagonism/biocontrol:
1. BLANK inhabit the vagina and help to keep the population of BLANK yeast low.

2. Use of antibiotics increases number of BLANK BLANK in the colon resulting in BLANK BLANK (PMC) which is fever, cramps, and diarrhea.

A. What toxins cause the problems in PMC?
B. How is it treated?

3. BLANK BLANK are used to control fungi in agricultural business.

Back 3

Ex:
1. Lactobacilli; Candida
2. Clostridium difficile; pseudomembranous colitis
A. Toxins A and B
B. Discontinue antibiotic therapy as treatment.

3. Beneficial bacteria

Front 4

An example of Synergism is where Enterococcus fecalis requires BLANK BLANK for growth and gets it from BLANK BLANK.

The BLANK produces BLANK which the lactobacilli needs.

Back 4

folic acid; Lactobacillus arabinosus

enterococci; phenyalanine

Front 5

What is the growth of microbes in tissues of the host called?

What is the result of an infecting microbe causing damage to the host called?

What are diseases transmitted from one host to the next called?

Back 5

Infection

Infectious disease

Communicable diseases

Front 6

What are microbial reservoirs?

What are examples of inanimate reservoirs? What microbes are found in each?

Back 6

Where infectious microbes can be found.

Inanimate reservoirs: soil, food, and water. Soil: anthrax spores. Food: E.coli in ground beef. Water: fecal coliforms.

Front 7

What is an animate reservoir called?

Describe the 3 types.

Back 7

Animate reservoirs are human beings

(1) healthy carriers: no visible signs of disease
(2) incubatory: before the clinical symptoms appear
(3) convalescent: recovered from disease with no symptoms, but still shed the agent.

Front 8

What is direct disease transmission? Name some examples.

Back 8

Pathogens transmitted directly to the host.
Ex:
1. syphilis and gonorrhea through person to person contact.
2. Anthrax through direct contact with infected animals

Front 9

What is an indirect disease transmission?

What are living organisms that indirectly transfer infectious agents like lice, fleas, ticks, dogs, cats, and rodents called?

Back 9

Pathogens transmitted via inanimate objects aka “fomites” such as dishes, clothing, needles and dust.

"Vectors"

Front 10

What are the portals of entry for pathogens to establish and spread into the host?

Back 10

nose, mouth, eyes, ears, genitourinary tract, cuts

Front 11

What are the 5 steps in the sequence of infectious diseases?

1. BLANK period
2. BLANK period: symptoms first appear.
3. BLANK period: symptoms reach their peak.
4. BLANK period: disease resolves.
5. BLANK period: patient recovers.

Back 11

1. Incubation period
2. prodromal period: symptoms first appear.
3. Acute period: symptoms reach their peak.
4. Decline period: disease resolves.
5. Convalescent period: patient recovers.

Front 12

The BLANK BLANK initially begins with a subclinical situation.

The microbe will grow and multiply and establish a BLANK of BLANK in the host.

Often no BLANK BLANK of disease.

Begins with exposure to the BLANK BLANK.

It is followed by the 4 steps of BLANK BLANK.

Back 12

Incubation period

focus of infection

clinical signs

etiological agent

Clinical illness

Front 13

BLANK BLANK lead to diseases that do not immediately produce detectable signs or symptoms.

Describe an example.

Some BLANK BLANK can cutoff BLANK system functions.

Back 13

Latent infections

Ex: Herpes simplex virus remains latent until stress causes it to grow. It otherwise remains dormant in host cells and is not totally eliminated by body’s host defense mechanisms.

Latent infections; immune.

Front 14

--Microbial Factors of Virulence: Mechanisms of Invasion--
Microbes must first BLANK then BLANK in the host tissues.

Most pathogens invade a specific tissue or organ. Name some examples and what they need to grow.

Some microbes adhere to specific tissues for invasion. Name an example.

What else aids in pathogenesis by microbes?

Back 14

survive then grow

Ex:
1. Shigella dysenteriae: colonizes the GI tract.
2. Brucella: grows in the placenta of infected animals and needs erythritol, a 4 carbon ROH, for growth.

Ex:
1. N. gonorrhoeae: possess pili to attach to urogenital mucosal epithelial cells.

Microbial enzyme

Front 15

What are microbial enzymes made by Streptococcus pyogenes that destroy RBC’s?

Describe the two types of this enzyme and what they do.

Back 15

Hemolysins

1. . Streptolysin O: is inactivated by oxygen; impacts RBC’s and WBC’s; with WBC’s it causes release of cytoplasmic granules.

2. Streptolysin S is oxygen stable; seen in lab.

Front 16

What does the microbial enzyme Streptokinase do?

Why is plasmin important for stroke patients within 4 hours?

Back 16

It is a protease that converts plasminogen in human serum to plasmin.

The plasmin dissolves blood clots and thus promotes disease spread.

Front 17

Capsules protect the microbe from what?

They are important in the virulence of what microbes?

Capsules are on the BLANK of gram negative microbes and outside BLANK BLANK of gram positive; gives a BLANK function.

What are capsules based on? How are capsule forming microbes treated?

Back 17

phagocytosis

Streptococcus pneumoniae, Klebsiella pneumoniae, Neisseria meningitidis, and Bacillus anthracis.

outside; cell wall; stealthy

Based on protein or carbs; use vaccines

Front 18

What are the 2 types of toxins produced by microbes?

Describe both.

Which type is released only upon death and lysis of the Gram negative cell?

Back 18

Exotoxins: a soluble protein released into the surrounding environment by the microbe during growth and metabolism.

Endotoxin: the lipopolysaccharide portion of the outer membrane. Lipid A is the toxic portion of the LPS molecule.

Endotoxin

Front 19

What is an exotoxin that impacts the small intestine?

What is an exotoxin that affects nerve tissue? Name an example and what it does.

What is an exotoxin that impacts all cells? Name an example.

Back 19

Enterotoxin; S. aureus impacts the small intestine.

Neurotoxin; Botulium toxin (1 mg could kill 1,000 people) blocks the release of acetylcholine.

Cytotoxin; Diphtheria toxin disrupts protein synthesis by knocking out EF2

Front 20

Exotoxins are converted to toxoids via BLANK BLANK.

Toxoids have lost their BLANK BLANK but are still BLANK, so will cause the production of an BLANK BLANK in humans.

Toxoids are the basis of BLANK like DPT.

Back 20

formaldehyde treatment

toxic activity; immunogenic; immune response

Vaccines

Front 21

--Endotoxin fact sheet!--

Bacterial source: ?
Location: ?
Toxic moiety: ?
Heat stability: ?
Toxicity: ?
Toxoid form produced: ?
Symptoms: ?
Detection: ?

Back 21

Bacterial source: Gram negative bacteria.
Location: lipopolysaccharide.
Toxic moiety: Lipid A.
Heat stability: 1 hr @ 121 C
Toxicity: low
Toxoid form produced: no
Symptoms: fever, inflammation, increased phagocytsis, rash, septic shock.
Detection: Limulus amoebocyte lysate assay (LAL) assay. Detects 10-12g (picogram) quantities of LPS.

Front 22

Endotoxins induce fever by causing the release of temperature elevating substances called BLANK BLANK from leukocytes.

Where do these substances act?

Endotoxins are usually from gram BLANK while exotoxins are from gram BLANK.

Back 22

endogenous pyrogens

At the hypothalamus

negative; positive

Front 23

--Endotoxins--
Septic shock is caused by an increase in BLANK BLANK, resulting in BLANK blood pressure.

Back 23

capillary permeability; reduced

Front 24

What host defense does not depend on prior exposure of the host to the invading organism?

Which host defense involves specific proteins, antibodies and white blood cells (T cells)? It is otherwise known as BLANK.

What are the 2 types of immunity? Describe them.

Back 24

Innate (nonspecific) resistance

Acquired (specific) resistance; Immunity

Immunity: humoral (antibodies, come from B cells) or cellular (T-cells).

Front 25

Nonspecific host resistance depends on what 5 things?

Back 25

1. Condition of the host
2. Physical barriers
3. Antimicrobial protection
4. Protective factors in the blood
5. Complement (C')

Front 26

--Nonspecific Host Resistance--
1. What are some conditions of the host?
2. What are some protections offered by physical barriers?
3. What are some antimicrobial protections? Describe them.

Back 26

1. factors such as sex, race, nutrition, stress and occupation.

2. A. Skin which is tightly packed epithelial cells.
B. Mucous membranes which line portals of entry like the respiratory tract.

3. A. lysozyme is produced in tears, saliva and nasal secretions and hydrolyzes cell wall peptidoglycan, resulting in cell lysis.
B. Interferon is an antiviral agent.
C. Sebaceous gland produces an oily substance to form a film on the skin’s surface called sebum.

Front 27

--Nonspecific Host Resistance--

4. What are some protective factors in the blood?
A. If the plasma is allowed to clot, the remaining fluid portion is called BLANK.
B. The serum contains different BLANK, BLANK, and BLANK. Antibodies interact with antigens.
C. Three major cellular components include: BLANK, BLANK, and BLANK.

5. What is complement (C')? Name an example.

Back 27

4. Plasma, a fluid portion, and a cellular portion.
A.serum
B.proteins, antibodies, and complement
C.erythrocytes (RBC), thrombocytes (platelets), and leukocytes

5. Series of cascading proteins. Ex: It allows lysis of a gram negative cell.

Front 28

What are the 3 cellular components of blood?

BLANK aka BLANK, contain BLANK and transport oxygen and CO2 in the circulatory system.

BLANK aka BLANK are involved in BLANK and the transport of serotonin.

BLANK lack BLANK differentiated into 5 types: BLANK, BLANK, BLANK, BLANK, and BLANK

Back 28

erythrocytes, thrombocytes (platelets), and leukocytes.

Erythrocytes aka RBC’s; hemoglobin

Platelets aka thrombocytes; coagulation

Leukocytes lack pigment; basophils, eosinophils, neutrophils, lymphocytes, and monocytes

Front 29

What leukocytes make up the granulocytes? How long do they live?

BLANK contain vasodilator BLANK, released during hypersensitive reactions and causes BLANK capillary permeability.

BLANK have an affinity for Ag-Ab (the bacteria is the antigen, etc.) complexes, which they BLANK.

BLANK, commonly called PMN’s, play a large role in BLANK, normally present in low numbers except during BLANK.

PMNs are BLANK.

Back 29

Basophils, eosinophils, and neutrophils; 2 weeks

Basophils; histamine; increased

Eosinophils; phagocytize

Neutrophils; phagocytosis; infections

polymorpho-neutrophils

Front 30

Agranulocytes are which Leukocytes? How long do they live?

BLANK are T cells which are BLANK BLANK or B cells which produce BLANK/BLANK

BLANK active in BLANK; macrophages are a differentiated form of them.

Back 30

Lymphocytes and monocytes; they do not contain cytoplasmic granules and are long living.

Lymphocytes; cellular immunity; immunoglobulins/antibodies

Monocytes; phagocytosis

Front 31

What two systems make up the primary defenses of the body? What is this system called?

BLANK BLANK consists of BLANK macrophages and BLANK macrophages.

BLANK BLANK is an interconnecting network of vessels that collects excess fluid called BLANK from the body’s tissues.

This fluid flows through small structures called BLANK BLANK, which contain BLANK and BLANK to help clear the lymph of pathogens.

Back 31

Reticuloendothelial system and the lymphatic system aka RES.

Reticuloendothelial system; wandering; stationary

Lymphatic system; lymph

lymph nodes; lymphocytes and macrophages

Front 32

What is the body’s nonspecific response to injury, irritation or infection called?

What is usually observed?

Back 32

Inflammation Response

Dilation and increased permeability of blood vessels which produces edema, erythema, pain, and heat.

Front 33

--Phagocytosis card 1--
What is phagocytosis?

Phagocytosis begins with BLANK and BLANK to the infectious agent.

BLANK BLANK released by pathogenic bacteria attract phagocytes.

Back 33

ingestion and digestion of foreign substances by cells, a part of the nonspecific defense in a host.

recognition and adherence

Chemotatic factors

Front 34

--Phagocytosis card 2--
Phagocytosis is reduced by the presence of BLANK BLANK, but is enhanced by the presence of BLANK.

BLANK are proteins that form a BLANK between BLANK of phagocytes and thus promote the process.

After BLANK, the phagocyte ingests the particle by extending BLANK around the object.

Back 34

bacterial capsules; opsonins

Opsonins; bridge between surfaces

attachment; pseudopods

Front 35

--Phagocytosis card 3--
Inside the cytoplasm it fuses with BLANK to form a larger structure a BLANK.

What helps to destroy the particle? (4)

Some bacterial pathogens inhibit phagocytosis like BLANK and BLANK.

What is Listeriosis?

Back 35

lysosomes; phagolysosome

Lysosomal enzymes, proteases, nucleases, lipases

listeria and mycobacteria

spontaneous abortion in pregnant females.