Exam - Pathogenic Organisms

Question 1

Name 4 pathogenic organisms

Answer 1

Bacteria, Viruses, Fungi, Protozoa

Question 2

What is a pathogenic organism?

Answer 2

An organism capable of causing disease

Question 3

What makes an effective pathogen?

Answer 3

Simple lifecycle
Rapid reproduction/replication
Small
Mutate - can change shape easily

Question 4

Give characteristics of bacteria

Answer 4

Can be parasitic
Can produce endospores
Replicate by binary fission
Single-celled
Lack nuclear membrane
Contain plasmids
Flagellum
Pilli
Slime capsule

Question 5

What is the function of the:
a) slime capsule
b) flagellum
c) pilli
of bacterial cells?

Answer 5

a) protective barrier
b) facilitates movement
c) Attachment to other cells and DNA transfer

Question 6

Describe the different shapes of bacterial cells

Answer 6

Rods (bacilli)
Spherical (cocci) - can be single, in groups or chains
Spiral

Question 7

Describe Leptospirosis and give 2 examples

Answer 7

Gram -ve cell wall, spirochete morphology, zoonotic disease usually contracted through infected urine.

1. Leptospira canicola - causes nephritis
2. Leptospira icterohaemorrhagia - causes hepatitis

Question 8

What is the causal agent of Campylobacteriosis?

Answer 8

Campylobacter

Question 9

What is the causal agent of MRSA?

Answer 9

Methicillin resistant staphylococcus aureus

Question 10

Give characteristics of Viruses

Answer 10

They are particles, not cells
Lack organelles
Need another cell to replicate (obligate parasites)
Smaller than a bacterial cell
Have a core of nucleic acid and a protein capsid
Can be helical or icosahedral

Question 11

Describe viral replication

Answer 11

Virion attaches to host and injects nucleic acid which then takes over the host’s metabolism and causes it to produce viral components. Full infective viral particles then released.

Question 12

What is a retro virus? Give an example

Answer 12

A virus that has a reverse method of replication. It is capable of transforming RNA to DNA which makes it very difficult to treat.

E.g. FIV (feline immunodeficiency virus)

Question 13

What is a bacteriophage?

Answer 13

A bacteria-eating virus

Question 14

Give characteristics of Protozoa

Answer 14

Larger than bacteria
Similar in structure to bacteria, but do possess a nucleus
Feed off other organisms
Have food vacuole and waste vacuole
parasitic to replicate (depend on host)
single-celled

Question 15

Give an example of a protozoa

Answer 15

Toxoplasma gondii causes Toxoplasmosis

Question 16

Name two types of fungi

Answer 16

Moulds and Yeasts

Question 17

Give characteristics of yeast and an example

Answer 17

Unicellular
round fungi
grow anaerobically
Larger than a bacterial cell
reproduce by budding

e.g. Candida albicans

Question 18

Give characteristics of mould and an example

Answer 18

Multicellular
Filamentous
Grow anaerobically
reproduce by budding

e.g. Microsporum canis - causes ringworm

Question 19

Define Zoonosis

Answer 19

Disease that affects both animals and humans

Question 20

What are endospores?

Answer 20

Resistant form of a bacteria that reactivates in the correct conditions

Question 21

Describe how bacteria can be identified

Answer 21

Gram Stain - negative or positive cell wall, will or wont retain the stain.
Culture - see what is resistant to
Examination under microscope to look a morphology
See if grows in aerobic or anaerobic conditions

Question 22

What are the 6 steps of the Chain of Infection

Answer 22

1. Causal agent - what is the pathogen?
2. Reservoir
3. Portal of exit
4. Mode of transmission
5. Portal of entry
6. Susceptible host

Question 23

Give an example of Leptospirosis Chain of Infection

Answer 23

1. Leptospira canicola
2. Rats
3. Excreted in urine
4. Indirect contact by contacting infected Urine
5. Ingestion
6. Animal or human host

Question 24

Describe the measures to prevent the spread of rabies into the UK

Answer 24

Quarantine and isolation (mandatory)
Vaccination
Pet passport
Euthanasia of infected animals

Question 25

What are 3 routes of transmission for MRSA and what would they cause?

Answer 25

Urinary catheter - UTI
IV cannula - septicaemia
Open wound - Wound infection

Question 26

What prophylactic treatments could be used to prevent infection?

Answer 26

Vaccination
Probiotics
Worming and flea treatments
Education of clients
Infection control methods

Question 27

Give an example of airbourne transmission

Answer 27

Cat Flu
Disease affecting the respiratory tract of cats
Respiratory secretions are released into air and breathed in by other cats

Question 28

What is a nosocomial infection?

Answer 28

Hospital acquired infection

Question 29

How would you reduce the occurrence of toxocariasis in children?

Answer 29

• wash hands after playing outside or with puppies/kittens
• encourage clients to pick up and dispose of faeces quickly and hygienically
• don’t allow pets to toilet near areas where children play

Question 30

How would you reduce the risk of a pregnant women contracting toxoplasmosis

Answer 30

• don’t handle litter trays
• wash veg
• thoroughly cook meat
• wear gloves when gardening

Question 31

Name 3 ways infection can be reduced

Answer 31

• client education
• prophylactic treatment
• infection control procedures

Question 32

Explain the role of nutrition, prophylactics and stress reduction in disease prevention

Answer 32

Good nutrition = healthy animal = proteins to repair tissues etc, = less likely to contract infection
Prophylactic = vaccination etc
Stress reduction = stress reduces immune system function and makes animal more susceptible to infection so reducing stress increases the immune system efficiency.