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Flashcards in Microbiology Deck (35)
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1
Q

What is endospores?

A

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

2
Q

Resistance of endospores is due to…?

A
Layered structure 
Dehydrated state
Low metabolic activity
High levels of small acid-solubleproteins 
High content of dipicolinic acid
3
Q

How is endospores produced?

A

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

4
Q

Function of capsule?

A

Protection
Increase adherence
Antiphagocytic
Antigenic

5
Q

Function of cell wall?

A
Layer of Peptidoglycans
Protects from mechanical damage
Protects from osmotic lysis
Influence pathogenicity
Influence staining propertiesq
6
Q

Cell wall in gram+ Bacteria

A

Thick layer of pepridoglycans
No outer membrane
Stains blue

7
Q

Cell wall in gram- bacteria

A

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

8
Q

Cell Wall in mycoplasms

A

No cell wall only membrane

9
Q

Flagella

A

“Tail” of protein confers motility

10
Q

Pili

A

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

11
Q

Monotrichous flagella

A

One flagella

12
Q

Lophotrichous flagella

A

Several flagella on one end

13
Q

Amphitrichous flagella

A

One flagella in each end

14
Q

Peritrichous flagella

A

Flagella all over

15
Q

Curve of bacterial growth

A

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

16
Q

Mesophiles

A

Grow in body temperature

17
Q

Psychrophiles

A

Grow in cold temperatures

18
Q

Termophiles

A

Grow in warm temperatures

19
Q

Aerobes

A

Needs oxygen

20
Q

Capnophiles

A

Needs CO2

21
Q

Anaerobes

A

Needs no oxygen

22
Q

Facultative anaerobes

A

Can grow both with/without oxygen

23
Q

Microaerophils

A

Requires low amount of oxygen

24
Q

Preservation of microorganisms

A

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

25
Q

Endogenous infections

A
From inside body
Damaged epithelial barriers
Weakened immune system
Microbial imbalance 
Access to where normally not present
26
Q

Exogenous infections

A
From outside body
Ingestion
Inhalation
Infusion/transplant
Sexual
Congenital
27
Q

Stages of infectious disease

A

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

28
Q

Colonization strategies

A

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

29
Q

Exotoxins

A
Produced by live bacteria, both gram+ and -
Proteins
Heat labile 
Potent toxins
Not pyrogenic 
Highly antigenic
Extrachromosomally determined synthesis
30
Q

Endotoxins

A
Component of cell wall in gram- bacteria
Lipopolysaccharide
Heat stable
Moderate non-specific toxins
Pyrogenic
Not antigenic
Encoded in chromosome
31
Q

Acute infection

A

Short severe clinical course

Cleared from body (or death)

32
Q

Chronic infection

A

Host fails to eliminate pathogen
Persistent shedding
Long lasting/ongoing

33
Q

Latent infection

A

Presence of pathogen without shedding

34
Q

What is an antibiotic?

A

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

35
Q

What is an antimicrobial agent?

A

Includes both antibiotics and synthetic compounds with antimicrobial activity