Introduction to microbes

Question 1

the microbial world

Answer 1

4 major groups

• Virus’
• Bacteria
• Fungi

• Parasites

Question 2

sizes of micro-organisms

Answer 2

smallest

• prions
• proteins
• mycoplasma
• mitochondria
• bacteria
• eukaryotic cells (yeast, protozoa, human cells)
• Worms

largest

Question 3

prions are

Answer 3

self replicating proteins

• Some features of microbes
• No nucleic acid
• E.g. BSC (mad cow)

Question 4

mitochondria

Answer 4

technically bacteria

Question 5

endosymbiosis and mitochondria

Answer 5

mitochondria are the result of endocytosis of aerobic bacteria

Question 6

virus’ require

Answer 6

a host tissue to replicate

Question 7

structure of a virus

Answer 7

Nucleic acid (DNA or RNA) covered into a protein coat and envelop with glycolipids on the surface (recognition).

Question 8

how can virus’ be classified

Answer 8

Baltimore classfication

a virus classification system that groups viruses into families, depending on their type of genome (DNA, RNA, single-stranded (ss), double-stranded (ds), etc..) and their method of replication.

Question 9

virus’ can have ………. or……….. DNA

Answer 9

single stranded or double stranded DNA

Question 10

Enveloped single stranded DNA

Answer 10

parovirus 19 (affects platelets and RBC)

Question 11

non-enveloped double stranded Virus’

Answer 11

• Adenovirus
• BK virus
• Human papilloma virus (cervical cancer)
• JC virus

Question 12

enveloped doubled stranded virus’

Answer 12

• Herpes
• Hep B
• Molluscum contagiousness

Question 13

viral RNA can be…

Answer 13

single stranded (posiitive or negative strand)

double stranded

Question 14

positive stranded RNA virus’

Answer 14

• Icosahedral or helical
• Enveloped
  
  • HIV
  • Hep C
  • Rubella
  • Encephalitis
  • Yellow fever virus
  • West Nile virus

Question 15

negative stranded RNA virus’

Answer 15

• Helical
• Enveloped
  
  • Ebola
  • Lassa
  • Marburg
  • Measles
  • Mumps
  • Influenza
  • Parainfluenza
  • Respiratory syncytial virus

Question 16

double stranded RNA virus’

Answer 16

• Icosahedral or helical
• Enveloped
  
  • HIV (Double positive-sense strand)
  • Hep C

Question 17

the tree of life

Answer 17

the tree of life is a metaphor which expresses the idea that all life is related by common descent. it is divided into:

• Eubacteria
• Eukaryotes
• Archaebacteria

Question 18

some bacteria are

Answer 18

obligate (replicate intracellularly e.g. mycobacterium tuberculosis)

Question 19

bacteria often carry

Answer 19

plasmids

Question 20

plasmids

Answer 20

• Carry virulence factors
• Antibiotic resistance (can be transferred between diff species)

Question 21

bacterial shapes

Answer 21

coccus

bacillus (rod)

spirillus

Question 22

arrangement of cocci

Answer 22

clusters- staph

chains- strep

Question 23

Gram staining

Answer 23

Is a common technique used to differentiate two large groups of bacteria based on their different cell wall constituents

Question 24

outline gram staining

Answer 24

(fans can intimidate dad sadly)

1. Fixation
2. crysrtal violet
3. iodine treatment
4. decolorisation
5. counter stain with safranin

Question 25

gram positive

Answer 25

purple

Question 26

gram negative

Answer 26

pink

Question 27

linnaean taxonomy

Answer 27

genus and species Staphylococcus aureus

Question 29

mecically important bacteria (big list just read)

Answer 29

Question 30

mechanisms of bacterial pathogenesis

Answer 30

- virulence factors - toxins

Question 31

bacterial virulence factors

Answer 31

o Host entry (e.g. polysaccharide capsule) o Adherence to host cells (e.g. pili and fimbriae) o Invasiveness (e.g. enzymes such as collagenase) o Iron sequestration (siderophores)

Answer 32

o Exotoxins (e.g.diphtheria toxin) * secreted o Endotoxins (lipopolysaccharide) * on surface recognised by host immune system

Question 33

oxygen tolerance: aerobes

Answer 33

* can survive in the presence of oxygen

Question 35

obligate aerobes

Answer 35

require oxygen for surivival

Question 36

oxygen tolerance: anaerobes

Answer 36

can survive in absence of oxygen

Question 37

obligate anaerobes

Answer 37

require oxygen-free environment for survival (unless able to form spores)

Question 38

difference between prokaryotes and eukaryotes table

Answer 38

Question 39

fungi can be divided into

Answer 39

yeast and moulds

Question 40

yeasts

Answer 40

single-celled organisms e.g. * Candida albicans * Cryptococcus neoformans * Pneumocystis jiroveci

Question 41

moulds

Answer 41

multicellular * Aspergillosis * Dermatophytes (ringworm, athletes foot)

Question 42

parasites can be divided into

Answer 42

protozoa and helminths

Question 43

protozoa

Answer 43

single-celled * Giardia lamblia * Trypanosoma cruzi

Question 44

## Footnote **Helminths**

Answer 44

**worms, multi-cellular** * Roundworms (e.g. enterobius vermicularis) * Tapeworms (e.g. taenia saginata) * Flukes (e.g. schistosoma mansoni)