Exam - Pathogenic Organisms Flashcards
Name 4 pathogenic organisms
Bacteria, Viruses, Fungi, Protozoa
What is a pathogenic organism?
An organism capable of causing disease
What makes an effective pathogen?
Simple lifecycle
Rapid reproduction/replication
Small
Mutate - can change shape easily
Give characteristics of bacteria
Can be parasitic Can produce endospores Replicate by binary fission Single-celled Lack nuclear membrane Contain plasmids Flagellum Pilli Slime capsule
What is the function of the: a) slime capsule b) flagellum c) pilli of bacterial cells?
a) protective barrier
b) facilitates movement
c) Attachment to other cells and DNA transfer
Describe the different shapes of bacterial cells
Rods (bacilli)
Spherical (cocci) - can be single, in groups or chains
Spiral
Describe Leptospirosis and give 2 examples
Gram -ve cell wall, spirochete morphology, zoonotic disease usually contracted through infected urine.
- Leptospira canicola - causes nephritis
- Leptospira icterohaemorrhagia - causes hepatitis
What is the causal agent of Campylobacteriosis?
Campylobacter
What is the causal agent of MRSA?
Methicillin resistant staphylococcus aureus
Give characteristics of Viruses
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
Describe viral replication
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.
What is a retro virus? Give an example
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)
What is a bacteriophage?
A bacteria-eating virus
Give characteristics of Protozoa
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
Give an example of a protozoa
Toxoplasma gondii causes Toxoplasmosis
Name two types of fungi
Moulds and Yeasts
Give characteristics of yeast and an example
Unicellular round fungi grow anaerobically Larger than a bacterial cell reproduce by budding
e.g. Candida albicans
Give characteristics of mould and an example
Multicellular
Filamentous
Grow anaerobically
reproduce by budding
e.g. Microsporum canis - causes ringworm
Define Zoonosis
Disease that affects both animals and humans
What are endospores?
Resistant form of a bacteria that reactivates in the correct conditions
Describe how bacteria can be identified
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
What are the 6 steps of the Chain of Infection
- Causal agent - what is the pathogen?
- Reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Susceptible host
Give an example of Leptospirosis Chain of Infection
- Leptospira canicola
- Rats
- Excreted in urine
- Indirect contact by contacting infected Urine
- Ingestion
- Animal or human host
Describe the measures to prevent the spread of rabies into the UK
Quarantine and isolation (mandatory)
Vaccination
Pet passport
Euthanasia of infected animals
What are 3 routes of transmission for MRSA and what would they cause?
Urinary catheter - UTI
IV cannula - septicaemia
Open wound - Wound infection
What prophylactic treatments could be used to prevent infection?
Vaccination Probiotics Worming and flea treatments Education of clients Infection control methods
Give an example of airbourne transmission
Cat Flu
Disease affecting the respiratory tract of cats
Respiratory secretions are released into air and breathed in by other cats
What is a nosocomial infection?
Hospital acquired infection
How would you reduce the occurrence of toxocariasis in children?
- 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
How would you reduce the risk of a pregnant women contracting toxoplasmosis
- don’t handle litter trays
- wash veg
- thoroughly cook meat
- wear gloves when gardening
Name 3 ways infection can be reduced
- client education
- prophylactic treatment
- infection control procedures
Explain the role of nutrition, prophylactics and stress reduction in disease prevention
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.
