Introduction to Microbes

Question 1

What broad types of microbes are there?

Answer 1

Bacteria, viruses, fungi and parasites

Question 2

What are prions?

Answer 2

Proteins which are able to make copies of themselves and spread from person to person

Question 3

What are some features of a virus?

Answer 3

Protein coat, envelope, nucleic acid (can be DNA or RNA), spikes for attachment

Question 4

What are bacteriophages?

Answer 4

Viruses that parasitises a bacterium by infected it and reproducing inside it

Question 5

What is the difference between endotoxin and exotoxin?

Answer 5

Endotoxin = part of bacterial structure
Exotoxin = proteins secreted by the bacteria that go out to surrounding blood/tissue

Question 6

For example, what is an exotoxin that acts on the bowel called?

Answer 6

Enterotoxin

Question 7

What layer do gram negative bacteria have that gram positive bacteria do not?

Answer 7

Lipopolysaccharide (LPS)

Question 8

What colour does the presence of LPS result in the Gram negative bacteria staining?

Answer 8

Pink/red

Question 9

What shapes can bacteria come in?

Answer 9

Coccus, spiritus, bacillus (also known as rods)

Question 10

How can cocci be arranged?

Answer 10

Clusters or chains

Question 11

What are the colours for a Gram positive/negative?

Answer 11

Positive = Purple
Negative = Red

Question 12

True or False:

Aerobes can survive in the presence of oxygen but obligate aerobes require oxygen for survival

Answer 12

True

Question 13

True or False:

Obligate anaerobes can survive without oxygen but this isn’t essential

Answer 13

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

Question 14

What are some examples of Gram positive cocci bacteria?

Answer 14

Staph aureus, 
coagulate negative staph, 
alpha haemolytic streptococci,
beta-haemolytic streptococci,
Streptococcus pneumoniae
Enterococcus faecalis

Question 15

What are some examples of Gram negative cocci bacteria?

Answer 15

Neisseria meningitidis,
Neisseria gonorrhoeae,
Moraxella catarrhalis,
Acinetobacter baunammii

Question 16

What are some examples of Gram positive bacilli bacteria?

Answer 16

Listeria monocytogenes,
Bacillus anthracis,
Bacillus cereus

Question 17

What are some examples of Gram negative bacilli bacteria?

Answer 17

Escherichia coli,
Klebsiella pneumoniae,
Proteus species,
Salmonella typhi,
Pseudomonas aeruginosa,
Haemophilia influenzae

Question 18

What are the mechanisms of bacterial pathogenesis?

Answer 18

Virulence factors (host entry, adherence to host cells, invasiveness, iron sequestration)

Toxins (exo and endo)

Question 19

What are some examples of single-called yeasts?

Answer 19

Candida albicans, cyptococcus neoformans, pneumocystis jiroveci

Question 20

What are some examples of multicellular moulds?

Answer 20

Aspergillosis species, dermatophytes

Question 21

What are some examples of single-called protozoa?

Answer 21

Giardia lamblia, cryptosporidium parvum, plasmodium falciparum, trypanosoma Cruz

Question 22

What are some examples of helminths?

Answer 22

Roundworms (eg enterobius vermicularis)
Tapeworms
Flukes