Chapter 6 HW- Microorganisms

Question 1

What are the types of microorganisms?

Answer 1

Bacteria, fungi, protozoa, and viruses

Question 2

List the basic structures of bacteria

Answer 2

a. Cell wall (gram-positive or gram-negative)
b. Cell membrane
c. External capsule or slim layer
d. Flagella
e. Pili or Fimbriae
f. Cytoplasm
g. Toxic substances (toxins – exotoxins and
endotoxins, and enzymes)
h. Endospores (latent form of the bacterium)

Question 3

How do bacteria reproduce?

Answer 3

By binary fission, the single DNA cell duplicates and divides the single cell divides into 2 identical daughter cells, each daughter cell then continues to divide.

Question 4

What are the limiting factors for bacterial growth?

Answer 4

a. insufficient nutrients and oxygen
b. the effects of increased metabolic wastes in the
area
c. changes in pH or temperature

Question 5

Penicillin is used to fight bacteria with which type of cell wall?

Answer 5

Gram-positive

Question 6

What is the meaning of nonpathogenic?

Answer 6

They do not usually cause disease

Question 7

What are nonpathogenic microorganisms and give examples?

Answer 7

Many microorganisms are classified as nonpathogenic because they do not usually cause disease; in fact, they are often beneficial.
Example: Staphylococcus and Candid found on skin, Lactobacillus acidophilus found in the intestines Escherichia coli found in the large and small intestines

Question 8

Compare three characteristics of a bacterium and a virus

Answer 8

a. Bacteria has a cell wall, virus does not
b. Bacteria reproduce through binary fission, Viruses
through attaching themselves to a host cell, which
injects its genetic material into the host cell, the
host cell uses the genetic material to produce more
viruses
c. Bacteria do not require a living host, viruses do
d. Uses an antibacterial drug to treat bacteria and an
antiviral drug to treat a virus
e. Viruses are smaller in size than bacteria

Question 9

Why are viruses so hard to control?

Answer 9

They can hide inside human cells and they lack their own metabolic processes or structures that might be attacked by drugs. They multiply rapidly and can become drug resistant. Can Mutate.

Question 10

Microbes or parasites reproduce in or on the body’s tissue is_________?

Answer 10

Infection

Question 11

Disease causing microorganisms “germs”

Answer 11

Pathogens

Question 12

Name three types of fungal infections

Answer 12

Tinea pedis (athlete’s foot), Candida (thrush), Histoplasma

Question 13

Name three types of diseases caused by protozoa.

Answer 13

Trichomoniasis, malaria, and amebic dysentery.

Question 14

Explain the benefits of resident flora and give examples of resident flora.

Answer 14

a. Benefits: in the intestinal tract, resident flora help in the synthesis of vitamin K and other digestive processes, helps prevent other organisms from establishing a colony
b. Examples: Gould p.98 and 99 1)Streptococci, haemophilous and staphylococci are found in the upper respiratory tract 2)staphylococcus and candida occur on the skin

Question 15

Name 3 organs of the body that do not contain resident flora and should be sterile.

Answer 15

lungs, bladder, kidneys, uterus, fallopian tubes, ovary, blood and cerebrospinal fluid

Question 16

Infections caused as a result of the body’s defenses being impaired, if resident flora from one area reaches another area it is not supposed to or the balance of the resident flora is not maintained.

Answer 16

Opportunistic infection

Question 17

Describe the modes of transmission for infection

Answer 17

a. Direct—no intermediary, touching an infectious lesion,
sexual intercourse
b. Indirect—has an intermediary, contaminated hand,
food, instruments, bed linens, etc. that carry
organisms.
c. Droplet—(oral or respiratory), when respiratory or
salivary secretions containing pathogens are expelled
from body and are inhaled directly by someone else
nearby or fall on nearby objects to be transmitted
indirectly. (ex. tuberculosis bacteria)
d. Aerosol(airborne)—smaller particles than droplets so
can stay suspended in the air for longer periods of
time, travel through air currents, infecting any new
hosts who inhale the particles. (Also, TB)
e. Vector-borne—When an insect or animal serves as an
intermediary host in a disease such as malaria.

Question 18

What are infections acquired in a healthcare facility (hospitals, nursing homes, doctor’s offices)

Answer 18

Nosocomial

Question 19

List some reasons 10% - 15% of patients acquire an infection in the hospital.

Answer 19

1) the increased presence of microorganisms in these settings
2) patients have contagious diseases
3) there is overcrowding
4) use of contaminated instruments
5) immunocompromised and weakened patients
6) chain of transmission through staff, diagnostic procedures, equipment, therapeutic aids and food trays. 7) also many microorganisms in healthcare settings are resistant to drugs

Question 20

List 4 of the most common types of nosocomial infections and which one of these four is the MOST common?

Answer 20

1) urinary tract infections
2) pneumonia
3) diarrhea,
4) surgical wound infection urinary tract infection is the most common, pneumonia is the most lethal.

Question 21

List 5 factors that decrease host resistance.

Answer 21

1) Old age or very young age
2) Genetic susceptibility
3) Immunodeficiency of any type
4) Malnutrition
5) Chronic disease
6) Impaired inflammatory response due to long term
use of glucocorticoid steroids.

Question 22

Explain why it is important to take the complete course of antimicrobial medication prescribed.

Answer 22

The complete course of medication should be taken because if all microbes are not eradicated, infection may recur. In addition, microbes mutate after drug exposure and become drug-resistant.

Question 23

Explain why viral infections are difficult to treat

Answer 23

Viral infections are difficult to treat because they are more difficult to culture and identify, and viruses exist inside host cells. Moreover, antiviral drugs can reduce replication, but they do not destroy the virus. Also in some cases drugs are effective only against actively replicating viruses, not against those in the latent stage.

Question 24

Why must a new influenza vaccine be developed every year?

Answer 24

Viral strains undergo frequent mutations, changing antigens, so cannot maintain a long-term immunity

Question 25

All blood, body fluids, and wastes are considered “infected” in any patient regardless of the patient’s apparent condition and therefore proper precautions should be taken.

Answer 25

Universal Precautions

Question 26

List 3 techniques that can be used when treating radiation therapy patients to reduce the likelihood of transmitting infectious agents.

Answer 26

1) adequately clean surroundings
2) Use disinfectants on inanimate objects after used/touched by patient such as the “O” ring, head rest, table, wingboard, etc.
3) sterilize fomites (brachytherapy instruments)
4) use antiseptics when appropriate.
5) gloving
6) wash hands properly and use alcohol based hand sanitizer when can’t wash hands
7) Properly dispose of needles

Question 27

What is the benefit of narrow spectrum drugs over broad spectrum drugs.

Answer 27

They are less likely to upset the balance of resident flora in the body which could lead to opportunistic infections.

Question 28

What are the local and systemic signs of bacterial infection.

Answer 28

a. Local—inflammation (pain, swelling, redness, warmth), purulent exudate. Also site dependent (coughing and sneezing if in the respiratory tract) (vomiting and diarrhea if in the digestive tract)
b. Systemic—fever, fatigue, weakness, headache, nausea. Even confusion, seizures or loss of consciousness if severe infection.

Question 29

Congestion in the lungs or a solidification of lung tissue due to fluids and solids rather than gas that normally fills the lungs.

Answer 29

Consolidation

Question 30

List 3 reasons drugs are not always necessary to treat an infection

Answer 30

1) Because the body’s own defenses are often adequate
to limit the infection.
2) Also many microbes are self-limiting.
3) If overuse, then microbes can become drug resistant.

Question 31

Can antibacterial drugs be used to treat viral infections? Why or Why not?

Answer 31

Antibacterial drugs block synthesis of a bacterial cell wall or interfere with bacterial metabolism, but viruses lack these components so antibacterial drugs have no effect on them.

Question 32

How is the influenza virus transmitted and what are the signs and symptoms of the virus?

Answer 32

a. Transmission—directly by respiratory droplet or
indirectly by contact with a contaminated object.

b. Signs/symptoms—sudden acute onset with fever and
chills, malaise, headache, muscle aching, sore throat,
nasal congestion, and unproductive or dry cough.