Unit 4: Infection and Bacterial Invasion

Question 1

_____ are foreign, infectious microbes that cause sickness and disease.

Answer 1

Pathogens

Question 2

_____ is the scientific study of disease.
* concerned with:
- _____ (cause)
- _____ (development)
- effects of the disease

Answer 2

Pathology

• etiology (cause)
• Pathogenesis (development)
• effects of the disease

Question 3

Invasion and growth of pathogens in the body

Answer 3

Infection

Question 4

Abnormal state in which part or all of the body is incapable of performing normal functions.

Answer 4

Disease

Question 5

Is an organism that shelters and supports the growth of pathogens.

Answer 5

Host

Question 6

_____ : A collection of different microbes in an environmental system.

_____: types of organisms present in a specific environmental habitat

Answer 6

Microbiome
Microbiota

Question 7

Relationships with the Host

• _____: prevent pathogens from causing infection.
• _____: living together

Answer 7

Microbial antagonism
Symbiosis

Question 8

The three types of Symbiosis

1. _____: one organism benefits, and the other is unaffected.
2. _____: both organism’s benefit
3. _____: one organism benefits and one is harmed. (One organism benefits at the expense of the other).

Answer 8

1. Commensalism
2. Mutualism
3. Parasitism

Question 9

Human Microbiome

Answer 9

Mouth
Skin
Digestive
Urogenital

Question 10

Examples of each Symbiosis

1. Commensalism
   _____ bacteria on the skin.
2. Mutualism
   _____ bacteria in the large intestine.
3. Parasitism
   _____ on a host cell (green).

Answer 10

1. Staphylococcus epidermidis bacteria on the skin.
2. E. coli (red) bacteria in the large intestine.
3. Influenza viruses (orange) on a host cell (green).

Question 11

_____Measurable changes which a physician uses to make a diagnosis (Identification of the disease).

_____ Subjective changes in body functions.

Answer 11

Sign
Symptom

Question 12

Types of Diseases

_____: A specific group of symptoms or signs that always accompanies a specific disease.

_____: transmitted directly or indirectly from one host to another.

_____: a very communicable disease that is capable of spreading easily and rapidly from one person to another.

_____: caused by microorganisms that normally grow outside the human body and are not transmitted from one host to another.

Answer 12

Syndrome
Communicable diseases
Contagious disease
Non-communicable diseases

Question 13

Classifying Infectious Diseases

Answer 13

1. Occurrence of disease
2. Severity or duration of a disease
3. The extent of host involvement

Question 14

Classifying Infectious Diseases

1. Occurrence of disease:
   * Disease occurrence is reported by:

_____: number of people contracting the disease during a specific time.

_____: number of people with the disease in a defined population, in a specified time.

Answer 14

Incidence (new cases)
Prevalence (all existing cases)

Question 15

Level of Diseases

Answer 15

SEEP

Sporadic
Endemic
Epidemic
Pandemic

Question 16

Classifying Infectious Diseases

2. Severity or duration of a disease:
   _____ (measles)
   _____ (herpes simplex)
   _____ (hepatitis B.)
   _____ (subacute sclerosis pan encephalitis)

Answer 16

Acute Infection
Latent Infection
Chronic Infection
Slow Virus Infection

Question 17

Presence of immunity to a disease in most of the population

Answer 17

Herd Immunity

Question 18

Classifying Infectious Diseases

3. The extent of host involvement:

• _____ affects a small area of the body
• _____ is spread throughout the body via the circulatory system.

Answer 18

Local infection
Systemic infection

Question 19

Infections and It’s Definition

_____ infection
acute infection that causes the initial illness.

_____ infection
occur after the host is weakened from primary infection.

_____ infection
does not cause any signs or symptoms of disease in the host.

Answer 19

Primary Infection
Secondary Infection
Subclinical or inapparent Infection

Question 20

Is one that makes the body more susceptible to disease or alters the course of a disease

Answer 20

Predisposing Factors

Question 21

_____ period (no signs or symptoms)

_____ period (mild signs or symptoms)

Answer 21

Incubation period
Prodromal period

Question 22

_____ A continual source of infection

Answer 22

Reservoirs of Infection

Question 23

SPREAD OF INFECTION

Reservoirs of Infection
* A continual source of infection.

_____: People who have a disease or are carriers of pathogenic.

_____: Zoonoses are diseases that affect wild and domestic animals and can be transmitted to humans.

_____ soil and water.

Answer 23

Human Reservoirs
Animal Reservoirs
Non-living Reservoirs:

Question 24

Modes of Infectious Disease Transmission

Answer 24

General Transmission
Human to Human Transmission

Question 25

General Transmission Abiotic environmental factors _____, _____, _____, _____ Animal Vectors _____ (Malaria, Dengue) _____ (Bubonic plaque)

Answer 25

Abiotic environmental factors - Wind - Water - Inhalation of spores - Entry into skin Animal Vectors - mosquitoes (Malaria, Dengue) - Fleas (Bubonic plaque)

Question 26

Human to Human Transmission _____ - Pathogen survives best inside the body Eg: HIV, Herpesviruses, Ebola _____ - Pathogen survives harsh environment - Pick up pathogen from surface or air Eg Influenza, norovirus _____ - Pathogens are in droplets, but do not survive long this way. Eg: Ebola, Bordetella pertussis _____ - Pathogens aerosolized and stay infective Eg: Influenza, Tuberculosis _____ Through contaminated water or food Eg: Cholera, Norovirus, Shigella

Answer 26

Direct Contact Indirect Contact Droplets Airborne Fecal - Oral

Question 26

Selected Zoonoses VIRAL Disease: Influenza (some types) Causative Agent: _____ Reservoir: _____ Transmission Due To: _____ Disease: Rabies Causative Agent: _____ Reservoir: _____, _____, _____, _____, _____ Transmission Due To: _____

Answer 26

Disease: Influenza (some types) Causative Agent: Influenzavirus Reservoir: Swine, birds Transmission Due To: Direct contact Disease: Rabies Causative Agent: Lyssavirus Reservoir: Bats, skunks, foxes, dogs, raccoons Transmission Due To: Direct contact (bite)

Question 27

Selected Zoonoses BACTERIAL Disease: Leptospirosis Causative Agent: Leptospira spp. Reservoir: _____ Transmission Due To: Direct contact with _____,_____,_____. Disease: Salmonellosis Causative Agent: Salmonella enterica Reservoir: _____ Transmission Due To: _____

Answer 27

Disease: Leptospirosis Causative Agent: Leptospira spp. Reservoir: Wild mammals, domestic dogs and cats Transmission Due To: Direct contact with urine, soil, water Disease: Salmonellosis Causative Agent: Salmonella enterica Reservoir: Poultry, reptiles Transmission Due To: Ingestion of contaminated food and water and putting hands in mouth

Question 28

Selected Zoonoses PROTOZOAN Disease: Malaria Causative Agent: Plasmodium spp. Reservoir: _____ Transmission Due To: _____

Answer 28

Disease: Malaria Causative Agent: Plasmodium spp. Reservoir: Monkeys Transmission Due To: Anopheles mosquito bite

Question 29

Selected Zoonoses HELMINTHIC Disease: Tapeworm (pork) Causative Agent: _____ Reservoir: _____ Transmission Due To: Ingestion of undercooked contaminated pork Disease: Trichinellosis Causative Agent: _____ Reservoir: _____ Transmission Due To: Ingestion of undercooked contaminated mea

Answer 29

Disease: Tapeworm (pork) Causative Agent: Taenia solium Reservoir: Pigs Transmission Due To: Ingestion of undercooked contaminated pork Disease: Trichinellosis Causative Agent: Trichinella spiralis Reservoir: Pigs, bears Transmission Due To: Ingestion of undercooked contaminated meat

Question 30

Infections patients acquire while receiving treatment for other conditions at a health care facility, or in-home health care environment.

Answer 30

nosocomial infections

Question 31

HAI Microorganisms in healthcare associated environment Compromised host Chain of transmission

Question 32

Microorganisms Involved in Healthcare-Associated Infections * _____ Bloodstream * _____ Surgical wound * _____ Diarrhea after abdominal surgery * _____ Bloodstream * _____ Urinary tract infections * _____ Urinary tract infections (most common cause) * _____ Urinary tract and pneumonia * _____ All sites * _____ All sites * Enterobacter spp. All sites * Acinetobacter baumannii All sites

Answer 32

* Coagulase-negative staphylococci Bloodstream * Staphylococcus aureus Surgical wound * Clostridium difficile Diarrhea after abdominal surgery * Enterococcus spp. Bloodstream * Candida spp. (fungus) Urinary tract infections * Escherichia coli Urinary tract infections (most common cause) * Pseudomonas aeruginosa Urinary tract and pneumonia * Klebsiella pneumoniae All sites * Enterobacter spp. All sites * Acinetobacter baumannii All sites

Question 33

Standard precautions

Answer 33

- Hand hygiene - Use of protective equipment - cough etiquette - disinfection of patient- care equipment

Question 34

Trasmission-based precautions

Answer 34

Contact Droplet Airborne

Question 35

Occurrence of Disease Several Factors: 1. The Preferred Portal of Entry • Many microorganisms can cause infections _____

Answer 35

only when they gain access through their specific portal of entry.

Question 36

Occurrence of Disease Several Factors: 2. Numbers of Invading Microbes • Virulence can be expressed as: • _____: = lethal dose for 50% of the inoculated hosts • _____ = infectious dose for 50% of the inoculated host

Answer 36

LD50 ID50

Question 37

Occurrence of disease Several Factors: 3. Adherence _____(ligands): • surface projections on a pathogen adhere to complementary receptors on the host cells • can be glycoproteins or lipoproteins and are frequently associated with fimbriae

Answer 37

Adhesins

Question 38

Occurrence of Disease Several Factors: 3. Adherence _____: alternative lifestyle • provide attachment and resistance to antimicrobial agents

Answer 38

Biofilms

Question 39

_____: A mixture of polysaccharides, proteins, and nucleic acids that bind the cells together ATTACHMENT GROWTH DISPERSAL

Answer 39

MATRIX

Question 40

How bacterial pathogens penetrate host defenses? 1. _____ • prevent them from being Phagocytized. 2. ______ • Proteins in the cell wall can facilitate adherence or prevent a pathogen from being phagocytized • _____: heat resistant and acid resistant produced by Streptococcus pyogenes.

Answer 40

1. Capsules 2. Cell wall components - M protein

Question 41

How bacterial pathogens penetrate host defenses? 3. _____: digest materials between cells and form or digest blood clots • _____ are bacterial enzymes that coagulate (clot) the fibrinogen in the blood into fibrin (threads). • _____ are bacterial enzymes that break down fibrin and thus digest clots formed by the body to allow more rapid diffusion of infectious bacteria. • _____ destroy IgA antibodies

Answer 41

Enzymes Coagulases Kinases IgA proteases

Question 42

How bacterial pathogens penetrate host defenses 4. _____ • Some microbes vary the expression of antigens, thus avoiding the host’s antibodies. 5. _____ • Bacteria may produce proteins that alter the actin of the host cell’s cytoskeleton, allowing bacteria into the cell.

Answer 42

Antigenic Variation Penetration into the Host

Question 43

4 Basic Ways 1. By using the host’s nutrients. 2. By causing direct damage in the immediate vicinity of the invasion. 3. By producing toxins, transported by blood and lymph, that damage sites far removed from the original site of invasion. 4. By inducing hypersensitivity reactions

Question 44

1. Using the Host’s Nutrients: Siderophores ◦ Bacteria get IRON from the host using _____ 2. Direct Damage • Host cells can be destroyed when pathogens metabolize and multiply inside the host cells

Answer 44

siderophores

Question 45

_____ ◦ Antigens that provoke the release of CYTOKINES (produced by host T cells): ◦ regulate immune response and mediate cell-to-cell communication ◦ High levels cause fever, nausea, and other symptoms.

Answer 45

Superantigens:

Question 46

_____ stimulate macrophages to RELEASE CYTOKINES in very high concentrations causing fever and shock (decrease in blood pressure).

Answer 46

Endotoxins