Microbiology

Question 1

What is endospores?

Answer 1

Dormant highly resistant bodies formed by some bacteria in adverse environmental conditions
Produced inside bacterial cell

Question 2

Resistance of endospores is due to…?

Answer 2

Layered structure 
Dehydrated state
Low metabolic activity
High levels of small acid-solubleproteins 
High content of dipicolinic acid

Question 3

How is endospores produced?

Answer 3

DNA replication
Cytoplasmic membrane invaginates creating forespore=first membrane
Cytoplasmic membrane engulfs forespore=second membrane
Calcium and dipicolinic add deposited btw membranes
Maturation=completion of spore coat
Release

Question 4

Function of capsule?

Answer 4

Protection
Increase adherence
Antiphagocytic
Antigenic

Question 5

Function of cell wall?

Answer 5

Layer of Peptidoglycans
Protects from mechanical damage
Protects from osmotic lysis
Influence pathogenicity
Influence staining propertiesq

Question 6

Cell wall in gram+ Bacteria

Answer 6

Thick layer of pepridoglycans
No outer membrane
Stains blue

Question 7

Cell wall in gram- bacteria

Answer 7

Thin layer of peptidoglycans
Outer membrane with lipopolysaccharides (endotoxic)
Stains pink

Question 8

Cell Wall in mycoplasms

Answer 8

No cell wall only membrane

Question 9

Flagella

Answer 9

“Tail” of protein confers motility

Question 10

Pili

Answer 10

Protein covering cell body
On gram- bacteria
For attachment or conjugation

Question 11

Monotrichous flagella

Answer 11

One flagella

Question 12

Lophotrichous flagella

Answer 12

Several flagella on one end

Question 13

Amphitrichous flagella

Answer 13

One flagella in each end

Question 14

Peritrichous flagella

Answer 14

Flagella all over

Question 15

Curve of bacterial growth

Answer 15

Lag phase-no initial growth, constant number
Exponential growth-high growth, number increases
Stationary phase-constant number
Decline phase-growth decreases, numbers decreases

Question 16

Mesophiles

Answer 16

Grow in body temperature

Question 17

Psychrophiles

Answer 17

Grow in cold temperatures

Question 18

Termophiles

Answer 18

Grow in warm temperatures

Question 19

Aerobes

Answer 19

Needs oxygen

Question 20

Capnophiles

Answer 20

Needs CO2

Question 21

Anaerobes

Answer 21

Needs no oxygen

Question 22

Facultative anaerobes

Answer 22

Can grow both with/without oxygen

Question 23

Microaerophils

Answer 23

Requires low amount of oxygen

Question 24

Preservation of microorganisms

Answer 24

Cryovials-freezing in liquid nitrogen
Lyophilization-freeze drying
Active culture- kept alive providing nutrients etc

Question 25

Endogenous infections

Answer 25

``` From inside body Damaged epithelial barriers Weakened immune system Microbial imbalance Access to where normally not present ```

Question 26

Exogenous infections

Answer 26

``` From outside body Ingestion Inhalation Infusion/transplant Sexual Congenital ```

Question 27

Stages of infectious disease

Answer 27

Host infection Colonization and growth Dissemination of pathogens in host Tissue damage

Question 28

Colonization strategies

Answer 28

Iron-chelating compounds (taking iron from transferrin/lactoferrin) Erythrocyte lysis (taking iron from Hb) Must tolerate micro environmental conditions Avoid immune system

Question 29

Exotoxins

Answer 29

``` Produced by live bacteria, both gram+ and - Proteins Heat labile Potent toxins Not pyrogenic Highly antigenic Extrachromosomally determined synthesis ```

Question 30

Endotoxins

Answer 30

``` Component of cell wall in gram- bacteria Lipopolysaccharide Heat stable Moderate non-specific toxins Pyrogenic Not antigenic Encoded in chromosome ```

Question 31

Acute infection

Answer 31

Short severe clinical course | Cleared from body (or death)

Question 32

Chronic infection

Answer 32

Host fails to eliminate pathogen Persistent shedding Long lasting/ongoing

Question 33

Latent infection

Answer 33

Presence of pathogen without shedding

Question 34

What is an antibiotic?

Answer 34

Microbial metabolites that kill or inhibit growth of bacteria Bactericidal-kills Bacteriostatic-inhibit growth

Question 35

What is an antimicrobial agent?

Answer 35

Includes both antibiotics and synthetic compounds with antimicrobial activity