Micro Bio Ch 14

Front 1

Symbiosis/Relationship

The relationship is really a spectrum of interactions

Back 1

• Mutualism

• Commensalism

• Parasitism

Front 2

Symbiosis/Relationship

: both benefit– Highly evolved and stable relationship– Termites and protozoa –wood

Back 2

:Mutualism

Front 3

Symbiosis

:-one benefits and otherunaffected

Back 3

:Commensalism

Front 4

– Normal flora- housed and fed

– Microbial antagonism (Collectively prevent infection by pathogen)

• Long lasting and stable relationship

• Result of long term evolution

Back 4

commensalism

Front 5

One benefits at expense of other

Back 5

Parasitism

Front 6

• Pathogen-causes disease

• Metabolically unstable relationship

• Host dies or eliminates pathogen

• Most successful parasites– maintain life processes without severelydamaging host

Back 6

Parasitism

Front 7

Sequence of Conditions

:Organisms present but no harm done(Inanimate & animate objects)/short time periodColonization: present on tissues: (Static or Growing)

Back 7

Contamination :

Front 8

Sequence of Conditions

:- multiplies and invades tissueMay have no observable effectsOr may have Signs & Symptoms of disease

Back 8

Infection:

Front 9

Sequence of Conditions

:- disrupts state of health, homeostasis isdisrupted.

Back 9

:Disease

Front 10

Capacity to produce disease

Back 10

Pathogenicity

Front 11

Pathogenicity

Capacity to produce diseaseFactors Include:

Back 11

– Adherence, Multiply on host, Ability to invade host or cause damage, Avoid being damaged by host’ defenses

Front 12

Intensity of disease produced

Back 12

virulence

Front 13

microorganism becomes more virulentwith each transfer through same/host species

Back 13

animal passage

Front 14

For example:

– influenza- first person usually milder, then more severe.

– organism better able to produce damage

– eventually reaches height of virulence

– population acquires immunity

Back 14

animal passage

Front 15

– some usually mild; others fatal

– greater from infected person than a carrier

– Infective dose: # of organisms required to cause clinical disease

Back 15

virulence

the intensity increases

Front 16

Weakening of disease producing ability ofpathogen

Back 16

Attenuation

Front 17

– pathogen passed to new host species and passedseveral times within that species

– eventually microorganism adapts to new hostand can’t cause disease in original host

– Pasteur & rabies vaccine-passed virus thoroughrabbits; became harmless to humans

Back 17

Transposal of virulence

Front 18

*Weakening of disease producing ability ofpathogen

*Transposal of virulence

– pathogen passed to new host species and passedseveral times within that species

– eventually microorganism adapts to new hostand can’t cause disease in original host

– Pasteur & rabies vaccine-passed virus thoroughrabbits; became harmless to humans

Back 18

Attenuation

Front 19

1 x10 13 body cells with 1 X1014 bacterial cell

– 10 times more microorganisms than cells

– Majority in colon

Back 19

Normal Flora (resident flora) Human body

Front 20

Viruses, fungi, protozoa not found in high #s

Back 20

Normal Flora/Human Body

Front 21

:always present

– Areas always exposed to or communicate with externalenvironment

– Usually do not cause disease

– Adapted to prevailing conditions

Back 21

Resident flora:

Front 22

– Acquired rapidly during & after birth

– Changes continuously through out life

– Reflects age, nutrition, & environment of person

Back 22

resident flora

Front 23

all normal flora are known as

Back 23

opportunists

Front 24

• Usually cause no disease

• Conditions allow them to cause disease

– Failure of host’s normal defenses

• Immunocompromised• Radiation or chemotherapy• Advance age or youth• Malnutrition• Other disease

Back 24

Opportunists(all normal flora)

Front 25

Presence of microorganisms, multiplication butno invasion– Normal flora– Transient flora

Back 25

colonization

Front 26

skin, colon, upper respiratory tract

Back 26

have micro organisms

Front 27

Most tissues & organs of the body are

Back 27

free of microorganisms

Front 28

normal flora can block/stop other organisms from taking up space

Back 28

microbial antagonism

example:

– Via competition for nutrients, space etc.– Produce harmful substances : toxins– pH in vagina maintained by bacteria 3.5-4.5• Prevents C. albicans from growing• Antibiotics allow yeast to grow and cause infection, change inpH

Front 29

• Ensures normal development of immune system

• Prevent over growth of harmful organism:

Back 29

Advantage of Normal Flora

:microbial antagonism

Front 30

Disadvantage of Normal FloraPotential for spread into sterile parts ofbody

Back 30

• Intestine may perforate• Skin broken• Extraction of tooth• Perianal skin flora enters urinary tract

Front 31

1• Adherence: glycoproteins/receptors

2• Colonization: growth on tissue surface

3• Invasion of Tissues: MolecularEnhancement Factors

Back 31

Sequence of Infection at the CellularLevel

but really we focus on 2 starting and then 3

Front 32

enzyme destroys hyaluronicacid(holds cells together) skin as the portal ofentry

its substrate is hyalmronic acid

coarum sysening* is what is happening here

Back 32

Hyaluronidase

Front 33

accelerates blood coagulation

*a growth medium

Back 33

Coagulase

Front 34

dissolves clots

*the blood clots reach a certain density they turn on this

Back 34

Streptokinase

Front 35

destroy neutrophils & macrophages

*destroy white blood cells, they are toxins

Back 35

Leukocidins

Front 36

are enzyme exotoxins that lyseRBCs

*destroy rbc's

Back 36

Hemolysins

Front 37

– partial breakdown ofhemoglobin

Back 37

Alpha (α) hemolysin

Front 38

- complete breakdown ofhemoglobin

Back 38

Beta hemolysin

Front 39

- No breakdown of RBC’s

Back 39

Gamma hemolysis

Front 40

is a substance poisonous to otherorganisms.

Back 40

A toxin

Front 41

is an altered toxinthat is used to produce antibodies

Back 41

A toxoid

Front 42

– soluble substances secreted intohost tissues

Back 42

Exotoxins

Front 43

– part of the cell membrane (G-)released during cell division or lysis.

Back 43

Endotoxins

Front 44

Clinical Presentation of DiseaseSigns, Symptoms, and Syndromes

observable disease characteristic

Back 44

sign

Front 45

Clinical Presentation of Disease Signs, Symptoms, and Syndromes

– disease characteristic felt only bythe patient. (pain, nausea, malaise)

Back 45

Symptom

Front 46

Clinical Presentation of Disease Signs, Symptoms, and Syndromes

– combination of signs andsymptoms indicative of a particular disease.

Back 46

Syndrome

Front 47

• Inherited• Congenital• Degenerative• Nutritional Deficiency• Endocrine• Mental• Immunological

Back 47

Noninfectious Diseases

Front 48

Noninfectious Diseases: Terms

- Some are caused by viruses

Back 48

Neoplastic*

Front 49

Noninfectious Diseases: Terms

-caused by any medical procedures,(sub-set of Nosocomial Infections)

Back 49

Iatrogenic

Front 50

Noninfectious Diseases: Terms

-unknown cause

Back 50

Idiopathic

Front 51

Types of Infectious Diseases:Caused by Infectious Agents

:diseases develop rapidly and run their coursequickly.

Back 51

Acute:

Front 52

Types of Infectious Diseases: Caused by Infectious Agents

:diseases develop more slowly and persist forlong time.

Back 52

Chronic:

Front 53

Types of Infectious Diseases: Caused by Infectious Agents

: agent remains inactive for a time andlater becomes active

Back 53

Latent diseases:

Front 54

Types of Infectious Diseases: Caused by Infectious Agents

:are confined to a specific area of thebody

Back 54

Local infections:

Front 55

Pathogens are widely distributed in :

Back 55

:many tissues in systemic infections.

Front 56

Types of Infectious Disease

(talking about acute here)

– initial infection in ahealthy person

Back 56

Primary (1degree) infection

Front 57

Types of Infectious Disease

– another infection inpeople weakened by the 1degree infection.

Back 57

Secondary (2degree) infection

Front 58

Types of Infectious Disease

: is caused by the distruction ofnormal microflora from broad-spectrumantibiotics

Back 58

A superinfection:

Front 59

Back 59

Front 60

Stages of Disease

- time between initialinfection and first appearance of Sighns and symptoms period

Back 60

Incubation period

Front 61

stages of disease

Patient is contagiousFactors:– Dependent upon virulence of organism– #s of organisms (infective dose)– Resistance of host– Site of entry into body

Back 61

Incubation period

Front 62

• Short period–only in some diseases, mildnon-specific symptoms.• Patient is contagious

Back 62

Prodromal Period

is in some diseases and not in others

Front 63

• Period of illness-most acute/very intense

Back 63

Invasive Period

Front 64

• The time when the S &S are intense • Overt signs and symptoms • Cough – Damage to mucosal cells by microbes – Excess mucous released – Neural centers elicit coughing

Back 64

Invasive Period

Front 65

The time when the S &S are at their greatest intensity is called

Back 65

Acme

Front 66

S & S subside• Host defenses & treatment overcome thepathogenRegain strength & recovery• Tissues repaired• Healing

Back 66

decline

Front 67

Secondary infections may occur in this phase

will not happen before, has to happen in this phase if at all

Back 67

decline

Front 68

• In some diseases, effects remaining after thedisease are called Sequelae• Examples: scarring, heart or kidney damage• In some cases sequelae are more harmfulthan the disease; (blindness after shingles)

Back 68

Convalescence Period

(make sure you know how to spell convalescence)

Front 69

In some diseases, effects remaining after the disease are called

Back 69

Sequela

a lot of times its worse than the disease.

Front 70

stages of a acute disease

Back 70

incubation period, prodromal phase, invasive phase, acme,decline, convalescence period