Pre-session slides 4PY008 Sterility & Asepsis.

Question 1

what is microbiological contamination?

Answer 1

Microbiological contamination refers to the
non-intended or accidental introduction of
infectious material like bacteria, yeast,
mould, fungi, virus, prions, protozoa or
their toxins and by-products

Question 2

Why do we as healthcare
professionals should be aware of this
problem?(4 reasons)

Answer 2

Contamination is undesirable
* Contamination may or may not lead to
Infection
Potential Infection Hazard!
*Contaminants may degrade the active
ingredients
*Contaminants may alter the physical
stability of product.
Why study contamination

Question 3

what does the degradation of API lead to?

Answer 3

Leads to reduced efficacy or complete
loss of efficacy

Question 4

Alter Physical Stability: Contaminants may alter…..?

Answer 4

Alter Physical Stability: Contaminants may alter the physical
stability of the product by changing the appearance, colour,
texture etc

Question 5

impact of Microbial
Contamination
on Medicinal Products

Answer 5

Major financial setback for manufacturer as batches are withdrawn/recalled
* Threat of litigation!
* Spread of disease rather than preventing or treating it.
* Common culprit: Pseudomonas spp.

Question 6

what’s a Opportunistic Organisms?

Answer 6

an organism that exists harmlessly as part of
the normal human body environment and does not become
a health threat until the body’s immune system fails

Question 7

Bacteria and yeast colonise more in the

Answer 7

moist areas of the skin such
as armpits

Question 7

On an average the skin sheds

Answer 7

the skin sheds 5 x 10 8 cells per day of which 90% are infected or colonised

Question 8

What is the composition of the plasma membrane according to the fluid mosaic model?

Answer 8

The plasma membrane is composed of a bilayer of amphipathic phospholipids. The outer surface consists of hydrophilic heads, while the inner surface consists of hydrophobic tails.

Question 9

How do hopanoids contribute to the structure and function of bacterial cell membranes?

Answer 9

Hopanoids are molecules similar to cholesterol found in eukaryotes. They regulate membrane rigidity and act as a permeability barrier, preventing the entry of hydrophilic and charged molecules.

Question 9

What role does the plasma membrane play in regulating the entry of molecules into bacterial cells?

Answer 9

The plasma membrane serves as a permeability barrier, preventing the entry of hydrophilic and charged molecules into bacterial cells. This selective barrier is essential for maintaining cellular homeostasis and protecting the cell from external substances.

Question 9

How does the fluid mosaic model describe the arrangement of molecules in the plasma membrane?

Answer 9

The fluid mosaic model suggests that the plasma membrane is a dynamic structure composed of various molecules, primarily phospholipids, arranged in a bilayer. This model highlights the fluidity and mosaic-like nature of the membrane due to the diverse array of embedded proteins and other molecules.

Question 9

What are the primary functions of the bacterial cell wall?

Answer 9

The bacterial cell wall functions to maintain cell shape and rigidity, protect the cell from osmotic lysis and toxic substances, and is essential for cell viability.

Question 10

What is the function of the hydrophilic heads and hydrophobic tails in the plasma membrane?

Answer 10

The hydrophilic heads form the outer surface of the plasma membrane, interacting with aqueous environments. The hydrophobic tails, on the other hand, face inward, shielding themselves from water and forming the core of the membrane.

Question 11

Why is the bacterial cell wall crucial for the survival of bacteria?

Answer 11

The cell wall is essential for bacteria to maintain their shape, resist osmotic pressure changes, and protect against harmful substances, thus ensuring their viability and survival.

Question 12

How does the bacterial cell wall protect against osmotic lysis?

Answer 12

The cell wall forms a rigid structure that prevents the bacterium from bursting due to changes in osmotic pressure in the surrounding environment.

Question 13

What impact do sterilization or disinfection processes have on bacterial cells with intact cell walls?

Answer 13

Sterilization or disinfection processes can damage bacterial cells by disrupting the integrity of the cell wall, leading to cell death.

Question 14

Describe the appearance of bacteria under a scanning electron microscope based on their shape.

Answer 14

Bacteria can appear as round ‘cocci’ (spherical) or rod-shaped ‘bacilli’ when viewed under a scanning electron microscope.

Question 15

What are bacterial endospores?

Answer 15

Bacterial endospores are dormant cells formed within a mother cell in response to environmental stress, such as nutrient limitation.

Question 16

How do bacterial endospores form?

Answer 16

Bacterial endospores form as a survival mechanism in response to unfavorable conditions, allowing the bacterium to enter a dormant state.

Question 17

What triggers the formation of bacterial endospores?

Answer 17

Environmental stresses like nutrient limitation can trigger the formation of bacterial endospores.

Question 18

Describe the structure of a bacterial endospore.

Answer 18

A bacterial endospore consists of a core surrounded by various protective layers.

Question 19

Where are bacterial endospores typically located within the cell?

Answer 19

Bacterial endospores can be located centrally, close to one end (sub-terminal), or at the terminal end of the cell.

Question 20

What makes bacterial endospores highly resistant?

Answer 20

Bacterial endospores are extremely resistant to heat, UV irradiation, chemical disinfectants, and desiccation due to their protective layers and dormant state.

Question 21

How do bacterial endospores contribute to bacterial survival?

Answer 21

Bacterial endospores enable bacteria to survive harsh environmental conditions until more favorable conditions return, allowing them to germinate and grow again.

Question 22

What is the purpose of sterilisation, disinfection, and preservation in controlling microorganisms?

Answer 22

They are used to prevent spoilage, foodborne illness, degradation, toxicity, and infection in food, medicines, cosmetics, surgical instruments, and surfaces to curb the spread of infection.

Question 23

Why is controlling microbial growth important in food?

Answer 23

: It prevents spoilage and reduces the risk of foodborne illnesses.

Question 24

How does sterilisation help prevent infection in medical settings?

Answer 24

By ensuring surgical instruments and equipment are free from microorganisms, reducing infection risks during medical procedures.

Question 25

What role does disinfection play in hospitals and kitchens?

Answer 25

Disinfection eliminates harmful microorganisms from surfaces, preventing the spread of infections.

Question 26

How does preservation of medicines and cosmetics contribute to safety?

Answer 26

It prevents microbial degradation and contamination, ensuring efficacy and safety for consumers.

Question 27

Why is disinfecting hands important for patients and staff?

Answer 27

It reduces the transmission of pathogens, protecting against infections spread via hand contact.

Question 28

What methods have been used for thousands of years to prolong the shelf life of food?

Answer 28

Refrigeration/freezing, smoking/salting, drying in sunlight, pickling, preserves/jams, and pasteurisation.

Question 29

Who is known as the Father of Bacteriology?

Answer 29

Louis Pasteur

Question 30

What significant theory did Louis Pasteur disprove?

Answer 30

He disproved the theory of spontaneous generation, showing that microbes could not develop without contamination

Question 31

Who is known as The Father of Modern Surgery?

Answer 31

Joseph Lister

Question 32

define STERILISATION?

Answer 32

s defined as a process of complete
destruction or elimination of all viable
microorganisms in or on a substance being sterilised.

Question 33

define disinfection

Answer 33

is defined as ‘the destruction of
microorganisms, but not usually bacterial spores; it
may not kill all microorganisms but reduces them to
a level which is neither harmful to health nor the
quality of perishable goods’

Question 34

what does the Latin term “sterilis” mean in the context of sterilisation?

Answer 34

The Latin term “sterilis” means “unable to produce offspring,” which reflects the goal of sterilisation to make an object or medium incapable of supporting microbial reproduction.

Question 35

Define a sterile object.

Answer 35

A sterile object is one that is entirely free of microorganisms that can reproduce, including bacteria, fungi, viruses, and spores.

Question 36

What is the recommended Sterility Assurance Level (SAL) for sterilisation processes?

Answer 36

The recommended Sterility Assurance Level (SAL) is 1 x 10^-6 and preferably less.

Question 37

what are the factors affecting sterilisation

Answer 37

ØInherent resistance exhibited by a genus, species,strain
ØPhysiological state of cells
ØEnvironmental factors induced by exposure before heat treatment, during heat treatment and after heattreatment.

Question 38

Define asepsis.

Answer 38

Complete absence of pathogenic
microorgansisms

Question 39

What does sterility imply microbiologically?

Answer 39

Microbiologically, sterility means the complete absence of viable cells, spores, and viruses. This condition ensures that no living microorganisms capable of growth or reproduction are present.Cells etc. could be present as long as they
are completely dead

Question 40

How can contamination from humans be prevented or limited in a manufacturing setting?

Answer 40

Contamination from humans can be reduced and contained by implementing strict hygiene protocols, including proper handwashing, wearing appropriate protective clothing (such as gloves and masks), and minimizing direct contact with products.

Question 41

What measures can be taken to prevent contamination from the environment in a manufacturing facility?

Answer 41

To prevent contamination from the environment, it’s important to control airflow and filtration systems to prevent the ingress of contaminants. Regular cleaning and maintenance of the facility and equipment also help to minimize build-up of environmental contaminants.

Question 42

How can contamination from ingredients be mitigated during production?

Answer 42

Contamination from ingredients can be addressed by carefully managing storage and handling practices to prevent cross-contamination. This includes using dedicated storage areas and equipment for different ingredients. Additionally, ensuring proper packaging techniques can further prevent contamination during production processes.

Question 43

What is the purpose of sterility testing in pharmaceutical or medicinal products?

Answer 43

Sterility testing is conducted to determine the presence or absence of living (viable) microorganisms in a sterilized pharmaceutical or medicinal product.

Question 44

Describe the two main approaches used in sterility testing.

Answer 44

terility testing involves two main approaches:

Looking for the growth of microorganisms themselves.
Detecting products or parts of microorganisms.

Question 45

What are the 3 limitations of sterility testing?

Answer 45

ØDestructive
ØFalse negatives
ØViruses not detected

Question 46

What is the Decimal Reduction Time (D-Value)?

Answer 46

The Decimal Reduction Time (D-Value) is defined as the time required at a specific temperature (or radiation dose) to achieve a 90% reduction in the number of viable microorganisms.

Question 47

What does the term Z-Value represent?

Answer 47

The Z-Value represents the increase in temperature required to decrease the D-Value of an organism by 90%.