Hygiene and disinfection

Question 1

What is the importance of hygiene practices around a farm?

Answer 1

• Prevent, contain, eliminate and reduce spread of infectious diseases around the environment
• Reducing disease challenge, the overall risk and severity of infectious disease reduce
• Reduce need for antibiotics
• Require veterinary input

Question 2

What is the most important step of hygiene practices around a farm?

Answer 2

Thorough cleaning and washing of surfaces is the most important step

Question 3

What are the 3 steps of cleaning and disinfection?

Answer 3

• Cleaning: removes 90-99% of bacteria
• Select an appropriate disinfectant for purpose
• Apply the disinfectant: correct method and concentration

Question 4

Describe the importance of air hygiene and ventilation

Answer 4

• reduced pathogen load
• dries environment so less supportive of microorganisms
• regulates the thermal environment

Question 5

How can pasture hygiene be maintained?

Answer 5

• Crop rotations
• Reseeding
• Different forage crops
• Resting pasture
• Stocking rates
• Not mixing age groups
• Putting younger animals on fresh grazing

Question 6

What are the welfare code industry guidelines regarding stocking rates?

Answer 6

• Age groups (older animals pass disease to younger)
• Batching of animals (all in all out)
• Cleaning out between batches
• Spreading disease within farm from one group to another e.g farm workers

Question 7

What is a biocide?

Answer 7

General term applies to substances used to control, prevent, or destroy harmful microorganisms (i.e., bacteria, viruses, or fungi)

Question 8

Give 4 examples of biocides

Answer 8

• Sanitisers
• Antiseptics
• Disinfectants
• Sterilisers

Question 9

How effective and saniters?

Answer 9

Do not destroy or eliminate all bacteria but reduce the number of microbial contamination on inanimate surfaces to levels that are considered safe from a public health standpoint

Question 10

What is sterilisation?

Answer 10

Refers to the process, either physical (i.e. extreme heat) or chemical (i.e. ethylene oxide), that destroys or eliminates all forms of life

Question 11

Compare a disinfectant and an antiseptic

Answer 11

Disinfectant = a product applied directly to an inanimate object. It destroys or irreversibly inactivates most pathogenic microorganisms, some viruses, but not usually spores
Antiseptic = applied to the surface of living organisms or tissues to prevent or stop the growth of microorganisms by inhibiting the organism or by destroying them

Question 12

What is a detergent?

Answer 12

Disperse and remove soil and organic material from surfaces allowing a disinfectant to reach and destroy microbes within or beneath the dirt

Question 13

Name some examples of chemical disinfectants

Answer 13

• Aldehydes
• Alkalis
• Acids
• Alcohols
• Halogens
• Phenols
• Oxidising agents

Question 14

What are some physical disinfection methods?

Answer 14

• Heat: steam cleaning, sterilisation
• Light
• Radiation

Question 15

Why are gram -ve bacteria more resistant to antiseptics and disinfectants?

Answer 15

The outer membrane of gram-negative bacteria acts as a barrier that limits the entry of many chemically unrelated types of antibacterial agents

Question 16

How do bacteria acquire resistance?

Answer 16

• mutation

- acquisition of genetic material in the form of plasmids or transposons