Infection Control And Microbiology

Question 1

What is a virion?

Answer 1

A virus particle

Question 2

Structure of a virus

Answer 2

Nucleocapsid - central core & capsid
Envelope- encases everything (only some)

Question 3

4 shapes of viruses

Answer 3

1. Helical
2. Icosahedral
3. Complex
4. Composite
   (5. Spherical)

Question 4

3 main animal virus shapes

Answer 4

1. Helical enveloped
2. Icosahedral enveloped
3. Icosahedral naked

Question 5

Virus replication

Answer 5

1. Virus attaches to host cell receptors
2. Virus enters host cell - phagocytosis or fuses to cell membrane
3. Virus DNA/RNA alters host cell metabolism to follow instructions
4. Virus replicates & instructs host cell to make more virions
5. New virions assembled & released by rupturing &destroying cell or exiting through the cell membrane

Question 6

Virus transmission,

Answer 6

Direct- physical contact, inhalation
Indirect- ingestion, vectorbourne

Question 7

Virus incubation

Answer 7

Lag time between infection & clinical symptoms developing
Takes time as virus has to invade, multiply & infect more cells

Question 8

How to diagnose viroinfections

Answer 8

Clinical signs & patient Hx
Election microscope to identify clumps (post Mortem)
Serology - detect antibodies & antigens
PCR

Question 9

Treatment of viral infections

Answer 9

IVFT
Nutrition
Anti bacterials to prevent secondary infection
Antivirals (human- Cascade)

Question 10

Prevention of viral infection

Answer 10

Border policies & requirements
Ventilated accommodation
Disinfectants to kill virus
Vaccinations

Question 11

Dog vaccinations

Answer 11

Parvovirus
Distemper
Rabies
Hepatitis
Kc

Question 12

Cat vaccinations

Answer 12

Calicivirus
FelV
Cat flu

Question 13

Rabbit vaccinations

Answer 13

Myxomatosis
Rabbit VHD

Question 14

Bacteria shapes

Answer 14

Cylindrical- bacilli, curved= vibrios
Spherical- cocci
Spirochaetes- spiral

Question 15

What are endospores?

Answer 15

Dormant bacteria that can survive in unfavourable conditions
Sporulation
E.g. tetanus, botulism, anthrax

Question 16

How can endospores be killed?

Answer 16

Heat, autoclave, steaming repeatedly

Question 17

What conditions do bacteria need to grow and reproduce

Answer 17

Temp
pH
Nutrients
Water
Correct gaseous environment

Question 18

3 types of bacteria gaseous requirements

Answer 18

Obligate aerobe- need O2
Obligate anaerobe- absence of O2
Facultative aerobe- grow when o2 but can function anaerobically

Question 19

How do bacteria reproduce

Answer 19

Binary fission - asexual reproduction
2 identical daughter cells

Question 20

What is conjugation

Answer 20

DNA passing from donor bacteria cell to recipient bacteria cell through a sex pilus

Question 21

What colour does gram positive bacteria stain

Answer 21

Purple

Question 22

What colour does gram negative bacteria stain

Answer 22

Pink

Question 23

How to identify bacteria

Answer 23

Microscopy
Culture & sensitivity- ID bacteria and antibacterial
Respiratory requirements

Question 24

Endotoxin vs exotoxin

Answer 24

Endotoxin- gram negative
Releases when cells die
Less toxic
Exotoxin- gram positive
When cells metabolise
Highly toxic and potent
Antitoxins neutralise (heat, chemical) = toxoid

Question 25

Bacterial diseases

Answer 25

Salmonella, campylobacter
Bordertella bronchiseptica
Leptospirosis
Staphylococcus spp
Clostridium tetani

Question 26

Treatment of bacterial infections

Answer 26

Antibiotics - narrow range , broad if infection
Anti inflammatories
IVFT
Gut flora meds

Question 27

2 types of fungi that affect animals

Answer 27

Moulds - multicellular
Yeasts - monocellular