Mircobiology

Question 1

What is a prion?

Answer 1

An infectious protein that has no DNA or RNa

Question 2

What do viruses consist of?

Answer 2

RNA or DNA (RNA is a retrovirus)
Protein coat
Sometimes a lipid capsule

Question 3

What are the components of a bacteria?

Answer 3

DNA or RNA
One double-stranded chromosome
Cell membrane
Cell wall (with or without a capsule)
Flagellae (movement)
Pili (adhesion)

Question 4

What are the 3 shapes of bacteria?

Answer 4

Coccus - round
Bacillus - rod-shaped
Spirochaetes - spirals

Question 5

What colour is a gram positive stain?

Answer 5

Purple

Positive purPle

Question 6

What colour is a gram negative stain?

Answer 6

Pink

Negative piNk

Question 7

Do gram positive or gram negative bacteria have a thick peptidoglycan wall?

Answer 7

Gram positive

Question 8

Do gram positive or gram negative bacteria have lipopolysaccharides?

Answer 8

Gram negative

Question 9

What is a pathogen?

Answer 9

A harmful organism

Question 10

What is a commensal?

Answer 10

An organism that is part of the normal flora

Question 11

What is an opportunistic pathogen?

Answer 11

An organism which will usually only cause infection in an immunocompromised individual

Question 12

What is a contaminant?

Answer 12

An organism that has got into a culture by accident

Question 13

What is pathogenicity?

Answer 13

The ability of a microorganism to produce disease

Question 14

What is virulence?

Answer 14

The degree of pathogenicity of an organism (how easily an organism can cause disease)

Question 15

What do bacteria require for growth?

Answer 15

Food
Moisture
Correct temperature
Correct pH

Question 16

What are the 3 main types of atmosphere for bacteria growth?

Answer 16

Aerobic - grow in presence of oxygen
Microaerophilic - atmosphere with reduced O and increased CO2
Anaerobic - no oxygen present

Question 17

What type of toxin does gram positive bacteria produce?

Answer 17

Exotoxin

Question 18

What type of toxin does gram negative bacteria produce?

Answer 18

Endotoxin

gram Negative eNdotoxin

Question 19

What are the two types of fungi?

How do they reproduce?

Answer 19

Moulds - produce spores

Yeasts - reproduce by budding

Question 20

Are streptococci or staphylococci classified by haemolysis?

Answer 20

Streptococci

Question 21

Are streptococci or staphylococci classified by coagulase?

Answer 21

Staphylococci

Question 22

Describe streptococcus

Answer 22

Aerobic gram positive cocci in chains

step, strip

Question 23

What are the 3 types of haemolysis or streptococci?

Answer 23

Alpha - partial haemolysis
Beta - complete haemolysis
Gamma - no haemolysis

Question 24

Which types of streptococcus cause alpha haemolysis?

Answer 24

Streptococcus pneumonia

Streptococcus viridans

Question 25

Which types of streptococcus causes beta haemolysis?

Answer 25

Group A strep (eg strep pyogenes) | Group B strep

Question 26

What is the most common group of non-haemolytic streptococcus?

Answer 26

Enterococci

Question 27

Describe staphylococcus

Answer 27

Aerobic gram positive cocci in clusters

Question 28

Which test is used to distinguish staphylococcus?

Answer 28

Coagulase

Question 29

What is the most common coagulase positive staphylococcus?

Answer 29

Staphylococcus aureus

Question 30

Where do coagulase negative staphylococcus tend to be found?

Answer 30

On the skin, eg staph epidermidis

Question 31

What is the treatment of choice for staphylococcus aureus infection?

Answer 31

Flucloxacillin

Question 32

What do gram negative cocci appear as on Gram film?

Answer 32

Diplococci (pairs)

Question 33

What are 2 examples of gram negative cocci?

Answer 33

Neisseria meningitides | Neisseria gonorrhoeae

Question 34

What are coliforms?

Answer 34

Species of gram negative bacilli that look like E.coli on gram film, and when cultured on blood agar

Question 35

What is clostridium?

Answer 35

Gram positive anaerobic bacilli

Question 36

What is bacteroides?

Answer 36

Gram negative anaerobic bacilli

Question 37

What is the first line treatment used for infections caused by anaerobes?

Answer 37

Metronidazole

Question 38

What is the gram stain of mycobacteria?

Answer 38

Nothing - they don't take up gram stain

Question 39

What bacteria causes tuberculosis?

Answer 39

Mycobacterium tuberculosis

Question 40

How does genetic variation occur in bacteria?

Answer 40

Mutation - failure of accurate replication of bacteria DNA Transformation - DNA released from dead bacteria and taken up by living bacteria Conjugation - transfer of plasmids Transduction - viruses infect bacteria can transfer bits of DNA from one bacterium to another

Question 41

What are the 5 ways any infection can spread?

Answer 41

``` Inhalation Ingestion Inoculation mother to Infant Intercourse ```

Question 42

What are the 5 moments for hand hygiene?

Answer 42

``` Before patient contact Before aseptic technique After body fluid exposure risk After patient contact After contact with patient surroundings ```

Question 43

What are the stages of viral replication?

Answer 43

``` Attachment Entry Nucleic acid and protein synthesis Assembly Release (by budding or lysis) ```

Question 44

By which mechanisms can antibiotics work?

Answer 44

Acting on bacterial cell wall Acting on the bacterial ribosome Acting on bacterial DNA directly

Question 45

Which antibiotics act on the bacterial cell wall?

Answer 45

Penicillins Cephalosporins Glycopepties

Question 46

What are the names of penicillins?

Answer 46

``` Penicillin Flucloxacillin Amoxicillin Temocillin Co-amoxiclav Piperacillin ```

Question 47

What are the names of the cephalosporins?

Answer 47

Ceftriaxone

Question 48

What are the names of the glycopeptides?

Answer 48

Vancomycin | Teicoplanin

Question 49

Which antibiotics inhibit protein synthesis?

Answer 49

Macrolides Tetracyclines Aminoglycosides Others

Question 50

What are the names of the macrolides?

Answer 50

Erythromycin Clarythromycin Azithromycin

Question 51

What are the names of the tetracyclines?

Answer 51

Doxycycline

Question 52

What are the names of the aminoglycosides?

Answer 52

Gentamycin

Question 53

What are the antibiotics that act on bacterial DNA?

Answer 53

Metronidazole Trimethoprim Fluoroquinolones

Question 54

What are the names of the fluoroquinolones?

Answer 54

Ciprofloxacin | Levofloxacin

Question 55

What are the 4 broad spectrum antibiotics?

Answer 55

Cephalosprins Co-amoxiclav Ciprofloxacin Clindamycin