Microbiology And Infection

Question 1

Classification of microbes

Answer 1

Viruses, bacteria , fungi, parasites ( Protozoa)

Question 2

What is relative size of microbes?

Answer 2

Bacteria = 1 micron 
Viruses = small + need electron microscope to see it
Protozoa = occupies mostly all cell

Question 3

What is 5 kingdom system?

Answer 3

Animalia 
Fungi 
Plantae
Protista 
Monera

Question 4

What is 3 domain system?

Answer 4

Bacteria
Eukarya
Archaea

Question 5

What are distinctive biological characteristics?

Answer 5

All organisms are cell except viruses 
Membranes 
Cellular + genome organisation
Single cells 
Multiple stages - life cycle 
Multicellular -parasites

Question 6

What is Linnaean classification?

Answer 6

Domain, kingdom, phylum, class, order, family, genus, species, strain, isolate

Question 7

What is sub species classification?

Answer 7

Differentiate pathogenic + non pathogenic strains

-> different disease patterns + clinical outcomes

Question 8

What is size of viruses?

Answer 8

20-300 nm

Question 9

Describe the structure of virus?

Answer 9

DNA/RNA genome
Linear , segmented , single or double stranded
Genome size = 9kb -300kb
Protein nucleocapsid -individual capsomeres
Helical, cubic or complex arrangement
No cytoplasm
Enveloped or non enveloped
Obligate intracellular organism => only grows + replicate inside other cells

Question 10

What is size of bacteria?

Answer 10

Size = 0.5 um - 3um

Question 11

Describe the structure of bacteria?

Answer 11

Prokaryotic 
Haploid DNA, circular genome 
No nucleus 
Usually have rigid cell wall outside cytoplasmic membrane 
No mitochondria 
Binary fission

Question 12

What is classification criteria for bacteria?

Answer 12

Morphology 
Gram stain
Growth requirements 
Biochemical reactions 
Serotype groups 
Antibiotics resistance 
rRNA sequencing 
Genome sequencing 
MLST or RFLP typing

Question 13

What is size of fungi- mycoses ?

Answer 13

Size = over 2 um

Question 14

Describe the structure of fungi?

Answer 14

Eukaryotic 
Haploid or diploid DNA 
Single or multiple nuclei 
Rigid chitinous cell wall outside cytoplasm 
Single or multicellular => e.g. Yeast

Question 15

Classifying fungi

Answer 15

Easier to consider by type of infection
Superficial mycoses = skin, nail, hair + mucous membrane
Cutaneous mycoses = e.g. ringworm - Tanea
Systemic mycoses= e.g. Histoplasmosis

Question 16

Give examples of fungal infections

Answer 16

Athlete’s foot
Ringworm
Tinea Ungurium

Question 17

What is parasite?

Answer 17

Term applied to any microbe that lives in or another animal host causing it harm

Question 18

What is size of Protozoa?

Answer 18

Single cell => size= 5-300um

Question 19

Describe the structure of Protozoa?

Answer 19

Single or multiple nuclei
Haploid DNA
Morphology varies throughout life cycle
May have flagella

Question 20

What are 3 groups of parasites?

Answer 20

Cestodes= tapeworms 
Trematodes= flatworms or flukes
Nermatodes= roundworms