Microbiology: Methods Of Sterilization Quiz Questions!

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Microbiology: Methods Of Sterilization Quiz Questions! - Quiz

Do you know anything about microbiology methods of sterilization? Sterilization refers to any method that kills life forms, such as microorganisms such as fungi, bacteria, viruses, spores, and unicellular eukaryotic organisms. Sterilization can be accomplished in many ways, including heat, chemicals, contamination, high pressure, and filtration. Upon sterilization, an item is described as being sterile. If you choose to learn more about methods of sterilization in microbiology, try this quiz.

Questions and Answers

1.

Microbial contamination is the non-intended or accidental introduction of infectious substances such as bacteria, yeast, fungi, mould, viruses, prions, protozoa and their toxins and also by-products. Contaminated microorganisms come from various sources such as air, water, dust, equipment and also humans. The main products at risk of contamination are topical products (e.g. creams), oral products, multi-dose products (e.g. eye drops), intravenous drugs (IV), contact lenses and also prostheses (e.g. surgical implants). Contamination has a substantial effect on pharmaceutical products used in the treatment and diagnosis of disease, as they contain a wide range of ingredients. They are therefore required to meet good and current pharmaceutical manufacturing standards. For instance, if impurities in form of microbes or chemicals were to be exposed to products during the manufacturing, packaging or storage process, the presence of the contaminants may render it unfit for use or contribute to the quality of the product, as well as reduce the efficacy or the standards that it has to meet. Degradation of active pharmaceutical ingredients (API), may lead to reduced or complete loss of efficacy. Another consequence of contamination would be the alteration of the physical stability of a product, such as the presence of fungal growth, resulting in gritty textures of creams. Micro-organisms release metabolites such as sour fatty acids, and fishy amines, which give a disagreeable taste and smell to products. Therefore, contamination is undesirable. Humans are the biggest sources of microbial contamination, whether in a hospital setting or in a production unit in an industry or clean room setting. For instance, handling products with hands, products can easily get contaminated and develop the Staphylococcus aureus organism. The skin typically shed 5 x 10^8 skin scales per day, in which 90% of the flakes are contaminated with bacteria. Another way of contamination may arise through natural flora of the human body is through respiratory droplets or saliva, which is easily spread through coughing or sneezing. For instance, the Streptococci species is commonly found in the throat or skin, this can also contribute to contamination. Indigenous opportunistic pathogens such as the Candida or Clostridium species, can greatly affect the shell life stability and safety of products. In serious cases, contamination of pharmaceutical products may lead to severe illnesses or death of a patient. There are various ways to prevent and control contamination from occurring in the production process of pharmaceutical products. An example would be to practise proper hygiene and sanitation controls in every level of the manufacturing process. Using strong aseptic techniques in clean room settings, would also reduce the risk of microbial contamination developing in products, or by utilising airlocks or air extraction when required. Transient flora is associated with skin surface, oral cavity and throat etc. It's exposed to multiple environmental assaults (e.g. soaps, detergents & antiseptics). Resident flora of the skin is found in deeper locations, such as sweat glands and pores in the skin, and it's not exposed to fluctuating conditions. It's produced by modulins produced by Staph epidermis, and may play a role in host defences (innate). These type of microbes contribute to contamination through direct contact or through contaminated environmental surfaces. A study performed by Rahman, 2002 on the microbial contamination of preservative-free eyedrops, concluded that preservatives significantly reduce the likelihood of contamination of eyedrops, and expert intervention reduced contamination. This suggests that preservatives are also good ways to prevent or reduce contamination. Another study based on the outbreak of neonatal deaths in Brazil associated with intravenous fluids, by Garret DO, et al, 2002, showed that endotoxin-contamination of intravenous liquids lead to neonatal deaths of 36 people. This indicated that sanitation controls in every level of manufacturing processes should be practised, in order to reduce microbial contamination. Humans as operators contribute to contamination through activity, clothing and behaviours. To monitor contamination levels, contact plates and the finger dabs test can be utilised in order to reduce contamination levels. To control contamination, hygiene and protective clothing should be utilised thoroughly, by hand washing, wearing clean room approved clothing (PPE), having appropriate training to carry out the task, have good general health and by also using good work procedures/practises.
2.

Disinfection is the destruction of microorganisms, it may not kill all microorganisms, but reduce it to a level acceptable for defined purpose. For instance, a level that is deemed as unharmful to health or the quality of products. Disinfectants work by destroying the cell wall of microbes or by interfering with their metabolism. Bacterial endospores are most resistant to disinfectants, although some viruses and bacteria possess some tolerance. They are extensively used in medical and health care, pharmaceutical industry, domestic and institutional areas and also for consumer products. There are many types of disinfectants such as quaternary ammonium compounds (QAC), biguanides and alcohols which are all non-oxidizing agents, they therefore attack all cellular material and prevent the microorganism from functioning. Chlorine, iodine and oxygen releasing compounds, are all known as oxidizing agents. These agents act by oxidizing the cell membrane of micro-organisms, resulting in the loss of structure; leading to cell lysis and potentially death. Disinfectants act on microorganism in two ways, by growth inhibition (bacteriostatic) or by lysis (bactericidal). The lethal effects are the desired outcome, as it suggests that the organism has been destroyed. The 3 main factors that influence antimicrobial effectiveness of disinfectants are: microbial, chemical and physical factors. Microbial factors include intrinsic resistance, acquired resistance and microbial susceptibility. Intrinsic resistance is the chromosomally mediated natural property of the organism. It occurs due to the differences in permeability of the outer cell layers. An example of this is the Pseudomonas aeruginosa bacterium, as it has natural resistance against drugs such as tetracycline, chloramphenicol and sulfonamides. It lacks uptake resulting from the inability of antibodies to achieve effective intracellular concentrations. Such natural insensitivity can be used to innate production of enzymes that inactivate the disinfectant. Acquired resistance results from a genetic change in the micro-organism, which may involve mutation or horizontal gene transfer via transformation, transduction or conjugation. An example of physical factors is temperature, which includes the reaction it has on the disinfectant. The activity of disinfectants increases as the temperature also increases. Temperature is ideally active over a wide range 5 to 55 degrees, it also affects the rate of reaction. Too much increase in temperature causes the disinfectant to degrade and weakens its bactericidal activity, and therefore may produce a potential health hazard. Chemical factors include: concentrations/dilution of disinfectant, pH, water hardness and also time. In terms of concentration, the higher the concentration, the longer it will take to kill microbes. For instance, Quaternary ammonium compounds (QACs) have concentration exponents of 1 and have an increased time factor of 2x when the concentration is ½. An increased pH level improves the antimicrobial activity of some disinfectants e.g. QACs but decreases the antimicrobial activity by altering the disinfectant molecule or the cell surface. Water hardness reduces the rate of kill of certain disinfectants because divalent cations e.g. magnesium and calcium in the hard water, interact with the disinfectant to form insoluble precipitates. Exposure of contact time must be within 5 minutes, and should increase by the use of alternative application methods The disinfectant must bind, traverse microbial cell wall and reach the target site.
3.

Which of the following is the best way of controlling contamination in a clean room?
- A.
  
  Hand washing and good working practices
- B.
  
  Hand washing, clean room clothing and clean room behaviour
- C.
  
  Hand washing, clean room clothing, clean room behaviour and good working practices
- D.
  
  Hand washing , clean room clothing and good work practices
- E.
  
  Hand washing, clean room behaviour and good working practices
Correct Answer
C. Hand washing, clean room clothing, clean room behaviour and good working practices

Explanation
The best way of controlling contamination in a clean room is by implementing a combination of hand washing, clean room clothing, clean room behavior, and good working practices. Hand washing helps to eliminate any potential contaminants on the hands, while clean room clothing helps to prevent the introduction of external contaminants into the clean room environment. Clean room behavior, such as avoiding unnecessary movements and minimizing the generation of particles, also helps to minimize contamination. Additionally, good working practices, such as following standard operating procedures and maintaining cleanliness, further contribute to contamination control in a clean room.

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4.

Which of the following is most correct regarding alcohol hand rubs?
- A.
  
  Removes dirt, active against all bacteria and active against all spores
- B.
  
  Removes dirt, not active against all bacteria and not active against all spores
- C.
  
  Does not remove dirt, not active against all bacteria and active against all spores
- D.
  
  Does not remove dirt, not active against all bacteria and not active against all spores
- E.
  
  Does not remove dirt, active against all bacteria and not active against all spores
Correct Answer
B. Removes dirt, not active against all bacteria and not active against all spores

Explanation
Alcohol hand rubs are effective in removing dirt from the hands, but they are not active against all bacteria and spores. While alcohol-based hand sanitizers can kill many types of bacteria, they may not be effective against certain strains or spores. Therefore, the statement "Removes dirt, not active against all bacteria and not active against all spores" accurately describes the properties of alcohol hand rubs.

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5.

Which of the following groups of organisms produce endospores?
- A.
  
  Penicillium and Aspergillus species
- B.
  
  Staphylococcus and Streptococcus species
- C.
  
  Clostridium and Bacillus species
- D.
  
  Gram negative bacteria
- E.
  
  Sporothrix species
Correct Answer
C. Clostridium and Bacillus species

Explanation
Clostridium and Bacillus species produce endospores. Endospores are a dormant form of bacteria that are highly resistant to harsh environmental conditions. They are formed within the bacterial cell and can survive for extended periods of time until favorable conditions for growth are present. Clostridium and Bacillus species are well-known for their ability to produce endospores, which allows them to survive in various environments and makes them difficult to eradicate.

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6.

For an aseptically dispensed product, which of the following are critical control points as defined by HACCP principles
- A.
  
  Hand washing procedures
- B.
  
  Clean room clothing
- C.
  
  Working in appropriate isolators
- D.
  
  Hygienically designed clean room
- E.
  
  All of the above
Correct Answer
E. All of the above

Explanation
All of the options listed (hand washing procedures, clean room clothing, working in appropriate isolators, hygienically designed clean room) are critical control points for an aseptically dispensed product. These control points are necessary to maintain the cleanliness and sterility of the product throughout the dispensing process, in accordance with HACCP principles.

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7.

Which of the following is an eukaryotic micro-organism?
- A.
  
  Burkholderia cepacia
- B.
  
  Candida albicans
- C.
  
  Helicobacter pylori
- D.
  
  Salmonella typhimurium
- E.
  
  Bacteriodes fragilis
Correct Answer
B. Candida albicans

Explanation
Candida albicans is an eukaryotic micro-organism because it is a type of fungus. Eukaryotes are organisms that have cells with a nucleus and other membrane-bound organelles, and fungi are one of the main groups of eukaryotes. Burkholderia cepacia, Helicobacter pylori, Salmonella typhimurium, and Bacteriodes fragilis are all prokaryotic micro-organisms, meaning they lack a nucleus and other membrane-bound organelles.

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8.

Which of the following is most correct when referring to types of contamination in a clean room?
- A.
  
  Only one type of contamination: viable (e.g. bacteria, viruses)
- B.
  
  Only one type of contamination: non-viable (e.g. dust, hair)
- C.
  
  Viable (e.g. bacteria, viruses) and non-viable (particulate or chemical)
- D.
  
  Non-viable (particulate not chemical) and viable (bacteria, fungi)
- E.
  
  Viable (viruses, fungi) and non-viable (chemical not particulate)
Correct Answer
C. Viable (e.g. bacteria, viruses) and non-viable (particulate or chemical)

Explanation
The correct answer is "Viable (e.g. bacteria, viruses) and non-viable (particulate or chemical)". This answer is the most correct because it includes both types of contamination that can be found in a clean room. Viable contamination refers to living organisms such as bacteria and viruses, while non-viable contamination refers to non-living particles such as dust or hair, as well as chemicals. This answer covers all the possible types of contamination that can be present in a clean room.

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9.

When should the identification of micro-organisms discovered during monitoring be identified:
- A.
  
  In all cases
- B.
  
  Once a week
- C.
  
  When limits are exceeded
- D.
  
  After limits are exceeded on more than one occasion
- E.
  
  Randomly
Correct Answer
A. In all cases

Explanation
Micro-organisms discovered during monitoring should be identified in all cases because identification helps in determining the type of micro-organism present and its potential impact on the system being monitored. This information is crucial for taking appropriate actions to control or mitigate any potential risks associated with the presence of the micro-organisms. Identifying them consistently ensures that any changes or trends in the microbial population can be detected and addressed promptly, maintaining the safety and quality of the system.

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10.

Members of the human microbiome are a significant problem/concern in contamination control as
- A.
  
  Quality assurance protocols for pharmaceutical products do not always select for these microorganisms.
- B.
  
  Quality assurance protocols for pharmaceutical products take into account the presence of the human microbiome.
- C.
  
  All members of the human microbiome cause disease in humans.
- D.
  
  All members of the human microbiome decrease the stability of the product.
- E.
  
  All of the above
Correct Answer
A. Quality assurance protocols for pHarmaceutical products do not always select for these microorganisms.

Explanation
The correct answer is "Quality assurance protocols for pharmaceutical products do not always select for these microorganisms." This means that quality assurance protocols may not always specifically target or detect the microorganisms present in the human microbiome. This suggests that the presence of the human microbiome may not be considered a significant concern in contamination control for pharmaceutical products, as the protocols do not always account for these microorganisms.

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11.

Select the cell envelope component that is a pyrogenic endotoxin
- A.
  
  Lipoprotein
- B.
  
  Lipolysaccharide
- C.
  
  Phospholipid
- D.
  
  Polysaccharide
- E.
  
  Lipoteichoics
Correct Answer
B. Lipolysaccharide

Explanation
Lipolysaccharide is the correct answer because it is a major component of the outer membrane of Gram-negative bacteria and is known to induce fever and inflammation in the body. It is a pyrogenic endotoxin, meaning it can cause fever when released into the bloodstream. Lipoprotein, phospholipid, and polysaccharide are not specifically known to have pyrogenic properties. Lipoteichoic acids are found in the cell walls of Gram-positive bacteria and do not have pyrogenic effects.

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12.

Which of the following statements regarding contamination is true?
- A.
  
  A drop of potassium chloride 0.9% is viable, E.coli is viable
- B.
  
  A drop of potassium chloride 0.9% is non-viable, E.coli is non-viable
- C.
  
  A drop of potassium chloride 0.9% is non-viable, E.coli is viable
- D.
  
  A drop of potassium chloride 0.9% is viable, E.coli is non-viable
- E.
  
  None of the above
Correct Answer
C. A drop of potassium chloride 0.9% is non-viable, E.coli is viable

Explanation
This answer is true because the statement implies that the drop of potassium chloride 0.9% does not support the survival or growth of E.coli, making it non-viable. However, E.coli is stated to be viable, meaning it can survive and grow in other conditions.

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13.

Which of the following groups of organisms produce endospores?
- A.
  
  Penicillium and Aspergillus species
- B.
  
  Staphylococcus and Streptococcus species
- C.
  
  Clostridium and Bacillus species
- D.
  
  Gram negative bacteria
- E.
  
  Sporothrix species
Correct Answer
C. Clostridium and Bacillus species

Explanation
Clostridium and Bacillus species are known to produce endospores. Endospores are a dormant, tough, and non-reproductive structure formed by certain bacteria as a response to unfavorable environmental conditions. These endospores allow the bacteria to survive harsh conditions such as high temperatures, desiccation, and exposure to chemicals or radiation. Clostridium and Bacillus species are both Gram-positive bacteria that are capable of forming endospores, making them resistant to adverse conditions and allowing them to persist in the environment for extended periods.

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14.

Which of the following lists of organisms produce endotoxins/pyrogens?
- A.
  
  S. typhimurium
- B.
  
  E.coli
- C.
  
  P.aeruginosa
- D.
  
  A, B and C
- E.
  
  S.aureus
Correct Answer
D. A, B and C

Explanation
The organisms S. typhimurium, E.coli, and P.aeruginosa are known to produce endotoxins/pyrogens. Endotoxins are a type of toxin that is released when the bacterial cell is damaged or destroyed, and they can cause fever and other inflammatory responses in the body. These organisms are commonly associated with infections and can cause various diseases in humans. Therefore, the correct answer is A, B, and C.

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15.

Which of the following areas of the body will possess the highest numbers of microbial cells?
- A.
  
  Hair
- B.
  
  Intestinal tract
- C.
  
  Urino-genital tract
- D.
  
  Skin
- E.
  
  Respiratory tract including oro-pharynx
Correct Answer
B. Intestinal tract

Explanation
The intestinal tract is home to a diverse and abundant population of microorganisms, known as the gut microbiota. This is because the intestines provide an ideal environment for microbial growth, with a constant supply of nutrients and a warm temperature. The gut microbiota plays a crucial role in digestion, nutrient absorption, and immune function. It is estimated that the number of microbial cells in the intestinal tract is in the trillions, making it the area of the body with the highest numbers of microbial cells.

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16.

The most widely used, effective, economical and reliable method of sterilization used in the health care setting is:
- A.
  
  Ethylene oxide
- B.
  
  Gas plasma
- C.
  
  Nuclear fusion
- D.
  
  Peracetic acid
- E.
  
  Steam
Correct Answer
E. Steam

Explanation
Steam is the most widely used, effective, economical, and reliable method of sterilization used in the healthcare setting. Steam sterilization, also known as autoclaving, uses high-pressure steam to kill microorganisms and spores on medical equipment and supplies. It is highly effective in eliminating a wide range of pathogens and is suitable for heat-resistant materials. Steam sterilization is cost-effective as it does not require the use of expensive chemicals or gases. Additionally, it is a reliable method as it can penetrate porous materials and has a shorter sterilization cycle compared to other methods.

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17.

Resident skin bacteria are best described as
- A.
  
  Located deep in epidermis
- B.
  
  Part of innate defence
- C.
  
  Effective removal by antiseptic scrub
- D.
  
  Washing may cause increase in numbers
- E.
  
  All the above
Correct Answer
E. All the above

Explanation
Resident skin bacteria are best described as being located deep in the epidermis, being part of the innate defense system, being effectively removed by antiseptic scrub, and potentially increasing in numbers due to washing.

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18.

Which of the following is the accepted Sterility Assurance Level (SAL) for pharmaceutical products?
- A.
  
  1 x 10⁶
- B.
  
  1 x 10^-6
- C.
  
  6 x 10⁶
- D.
  
  1 x 10^-16
- E.
  
  1 x 10^-60
Correct Answer
B. 1 x 10^-6

Explanation
The accepted Sterility Assurance Level (SAL) for pharmaceutical products is 1 x 10-6. SAL is a measure of the probability of a viable microorganism being present on a product after sterilization. A SAL of 1 x 10-6 means that there is a one in a million chance of a viable microorganism being present on the product. This level of sterility is considered acceptable for pharmaceutical products to ensure patient safety and prevent contamination.

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19.

A pharmaceutical product contains 1 x 10¹² cfu/mL, how many decimal reductions are required to reach the accepted SAL?
- A.
  
  18
- B.
  
  180
- C.
  
  0.18
- D.
  
  10
- E.
  
  1.8
Correct Answer
A. 18

Explanation
To calculate the number of decimal reductions required to reach the accepted SAL (Sterility Assurance Level), we need to convert the given concentration of 1 x 10^12 cfu/mL to a decimal form. The decimal form of the concentration is 0.000000000001 cfu/mL. Since the accepted SAL is typically 10^-6, we can calculate the number of decimal reductions by dividing the initial concentration by the accepted SAL. In this case, 0.000000000001 / 0.000001 = 1,000,000. Therefore, 18 decimal reductions are required to reach the accepted SAL.

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20.

If a microorganism has a D₆₀ of 0.5 minutes, for how long would you have to heat a suspension the microorganism at 60^OC to achieve 8 decimal reductions of the cell population?
- A.
  
  10
- B.
  
  14
- C.
  
  4
- D.
  
  40
- E.
  
  8
Correct Answer
C. 4

Explanation
If a microorganism has a D60 of 0.5 minutes, it means that it takes 0.5 minutes for the population of microorganisms to decrease by 1 log (or 90%). To achieve 8 decimal reductions, we need to decrease the population by 8 logs (or 99.999999%). Since each log reduction takes 0.5 minutes, it would take 4 minutes (8 x 0.5) to achieve 8 decimal reductions of the cell population.

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21.

Which of the following statements about low temperature gas plasma sterilisation is correct?
- A.
  
  Uses fourth state of matter as a sterilising agent
- B.
  
  Generates free radicals from gases
- C.
  
  Plasma glow emits Ultra violet light
- D.
  
  Used to sterilise surfaces of medical equipment
- E.
  
  All the above
Correct Answer
E. All the above

Explanation
Low temperature gas plasma sterilization utilizes the fourth state of matter, plasma, as a sterilizing agent. This process generates free radicals from gases, which are effective in killing microorganisms. The plasma glow emitted during this sterilization process does not emit ultraviolet light. Additionally, low temperature gas plasma sterilization is commonly used to sterilize the surfaces of medical equipment. Therefore, the correct answer is "All the above."

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22.

Which of the following describes the Gram positive cell envelope structure?
- A.
  
  Thin layer of peptidoglycan and teichoic acids
- B.
  
  Thin layer of peptidoglycan and lipopolysaccharides
- C.
  
  Thick layer of peptidoglycan, periplasm and lipopolysaccharides
- D.
  
  Thick layer of peptidoglycan and lipoteichoic acids
- E.
  
  Thick lipopolysaccharide layer and thin layer of peptidoglycan
Correct Answer
D. Thick layer of peptidoglycan and lipoteichoic acids

Explanation
The Gram positive cell envelope structure is characterized by a thick layer of peptidoglycan and lipoteichoic acids. This structure provides rigidity and protection to the cell. The peptidoglycan layer is responsible for the cell's shape and prevents osmotic lysis. Lipoteichoic acids are anchored in the cytoplasmic membrane and extend through the peptidoglycan layer, providing additional support and playing a role in cell adhesion and host-pathogen interactions. This structure is different from Gram negative cell envelopes, which have a thin layer of peptidoglycan and an outer membrane containing lipopolysaccharides.

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23.

Which of the following is a eukaryotic micro-organism?
- A.
  
  Burkholderia cepacia
- B.
  
  Helicobacter pylori
- C.
  
  Candida albicans
- D.
  
  Salmonella typhimurium
- E.
  
  Bacteroides fragilis
Correct Answer
C. Candida albicans

Explanation
Candida albicans is a eukaryotic microorganism because it is a type of fungus. Eukaryotic organisms have cells that contain a nucleus and other membrane-bound organelles, and they can be single-celled or multicellular. Candida albicans is a single-celled fungus that is commonly found in the human body, particularly in the mouth and genital areas. It can cause infections, especially in individuals with weakened immune systems.

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24.

Which of the following statements is false?
- A.
  
  Endospores are produced in response to unfavourable conditions
- B.
  
  Endospores are survival and dispersal structures produced by Pseudomonas aeruginosa
- C.
  
  Bacillus cereus produces endospores
- D.
  
  Endospores are produced by Clostridium difficile
- E.
  
  Endospores can be inactivated by hypochlorite disinfectants
Correct Answer
E. Endospores can be inactivated by hypochlorite disinfectants

Explanation
Endospores are highly resistant structures that are produced by certain bacteria, such as Bacillus cereus and Clostridium difficile, in response to unfavorable conditions. They are not easily inactivated by disinfectants, including hypochlorite disinfectants. Therefore, the statement "Endospores can be inactivated by hypochlorite disinfectants" is false.

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25.

Which of the following organisms is an opportunistic pathogen that has been associated with contaminated eye drops and ointments
- A.
  
  Clostridium species
- B.
  
  Pseudomonas aeruginosa
- C.
  
  Erwinia species
- D.
  
  Salmonella meunchun
- E.
  
  Chromobacter species
Correct Answer
B. Pseudomonas aeruginosa

Explanation
Pseudomonas aeruginosa is an opportunistic pathogen that has been associated with contaminated eye drops and ointments. This bacterium is known for its ability to infect the eyes and cause severe eye infections, especially in individuals with compromised immune systems. It can contaminate eye care products during manufacturing or due to improper storage and handling, leading to infections when these products are used. Therefore, Pseudomonas aeruginosa is the correct answer in this case.

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26.

Which of the following are the obligatory test organisms in BSEN 1276?
- A.
  
  S. aureus, S, typhimurium, E. coli, P. aeruginosa
- B.
  
  P. aeruginosa, E. coli, E. hirae, S. aureus
- C.
  
  E. coli, S. aureus, P. aeruginosa, A. niger
- D.
  
  E. coli, Enterobacter cloacae, S. typhimurium, P. aeruginosa
- E.
  
  E. hirae, C. albicans, A. niger, S. aureus.
Correct Answer
B. P. aeruginosa, E. coli, E. hirae, S. aureus

Explanation
The correct answer is P. aeruginosa, E. coli, E. hirae, S. aureus. These organisms are considered obligatory test organisms in BSEN 1276, which is a standard for evaluating the antimicrobial activity of disinfectants and antiseptics. They are commonly used in testing because they represent different types of microorganisms, including Gram-negative bacteria (P. aeruginosa, E. coli), Gram-positive bacteria (E. hirae, S. aureus), and both environmental and pathogenic bacteria. By using these organisms in testing, it allows for a comprehensive evaluation of the effectiveness of disinfectants and antiseptics against a wide range of microorganisms.

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27.

Which of the following is an example of an oxidising disinfectant
- A.
  
  Gluteraldehyde
- B.
  
  Peracetic acid
- C.
  
  Benzoic acid
- D.
  
  Chlorhexidine
- E.
  
  Propranol
Correct Answer
B. Peracetic acid

Explanation
Peracetic acid is an example of an oxidising disinfectant because it has strong oxidizing properties. It can break down organic matter and kill microorganisms by oxidizing their cell walls and proteins. This makes it an effective disinfectant for a wide range of applications, including medical and industrial settings.

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28.

Which of the following is a definition of disinfection?
- A.
  
  The destruction of all viable micro-organisms
- B.
  
  Reduction of viable micro-organisms to an appropriate level but not usually bacterial endospores
- C.
  
  Prevention of growth of all viable organisms
- D.
  
  Inactivation of all micro-organisms including spores
- E.
  
  Removal of all viable organism
Correct Answer
B. Reduction of viable micro-organisms to an appropriate level but not usually bacterial endospores

Explanation
Disinfection is the process of reducing the number of viable micro-organisms to a level that is considered safe and appropriate. This process does not usually eliminate bacterial endospores, which are highly resistant to disinfection methods. Therefore, the correct definition of disinfection is the reduction of viable micro-organisms to an appropriate level but not usually bacterial endospores.

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29.

Which of the following is/are included in the bactericidal disinfectant test (BSEN 1276) to simulate the presence of interfering substances?
- A.
  
  Bovine serum albumin
- B.
  
  Inactivator
- C.
  
  Water of standard hardness
- D.
  
  Ovine blood
- E.
  
  Glucose solution
Correct Answer
A. Bovine serum albumin

Explanation
Bovine serum albumin is included in the bactericidal disinfectant test (BSEN 1276) to simulate the presence of interfering substances. This is because bovine serum albumin is a common protein found in blood and other bodily fluids, and its presence can affect the efficacy of disinfectants. By including bovine serum albumin in the test, it allows for a more realistic simulation of real-life conditions where interfering substances may be present.

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30.

Which of the following lists of organisms are sources of endotoxic pyrognes?
- A.
  
  E. coli, E.hirae, S.aureus
- B.
  
  E. coli, S.aureus, P.aeruginosa, A.niger
- C.
  
  E. coli, Enterbacter cloacae, Streptococcus pyogenes
- D.
  
  S. typhimurium, E.coli, P.aeruginosa
- E.
  
  C. albicans, A.niger, S.aureus.
Correct Answer
D. S. typHimurium, E.coli, P.aeruginosa
31.

Which of the following is true of viruses?
- A.
  
  Capable of growth in pharmaceutical products, may produce toxins and release pyrogens
- B.
  
  Capable of growth in pharmaceutical products, sensitive to heat and radiation
- C.
  
  Incapable of growth in pharmaceutical products, sensitive to radiation and heat.
- D.
  
  Incapable of growth in pharmaceutical products, may produce resistant cysts
- E.
  
  Incapable of growth in pharmaceutical products, but can release heat resistant pyrogenic toxins
Correct Answer
C. Incapable of growth in pHarmaceutical products, sensitive to radiation and heat.

Explanation
Viruses are incapable of growth in pharmaceutical products because they require a host cell to replicate. They are also sensitive to radiation and heat, which can be used to destroy or inactivate them.

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32.

Which of the following is the best description of chlorhexidine?
- A.
  
  Clean surface disinfectant
- B.
  
  Quaternary ammonium compound used as a preservative for eye drops
- C.
  
  An aldehyde used for instrument disinfection
- D.
  
  An ester used for preservation of oral and topical products
- E.
  
  A biguanide disinfectant used for clean instrument disinfection and preservation of eye drops and lens solutions
Correct Answer
E. A biguanide disinfectant used for clean instrument disinfection and preservation of eye drops and lens solutions

Explanation
Chlorhexidine is a biguanide disinfectant that is used for clean instrument disinfection and preservation of eye drops and lens solutions. It is not a quaternary ammonium compound used as a preservative for eye drops, an aldehyde used for instrument disinfection, or an ester used for preservation of oral and topical products.

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33.

Which of the following describes acquired antimicrobial resistance?
- A.
  
  Chromosomally mediated natural property of the organism
- B.
  
  Due to inherent differences in the permeability of the outer cell layers
- C.
  
  Occurs due to a genetic change through mutation or genetic transfer
- D.
  
  Innate natural resistance of the organism
- E.
  
  Both B and D
Correct Answer
C. Occurs due to a genetic change through mutation or genetic transfer

Explanation
Acquired antimicrobial resistance refers to the development of resistance to antimicrobial drugs in microorganisms through genetic changes. This can occur through mutations in the organism's genes or through the transfer of resistance genes from other microorganisms. This process is not a natural property of the organism or due to inherent differences in cell permeability. Therefore, the correct answer is "Occurs due to a genetic change through mutation or genetic transfer."

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34.

Which of the following list of organisms are in the sequence from least susceptible to most susceptible to disinfectants?
- A.
  
  Mycobacteria, Trophozoites, Fungi, Lipid enveloped viruses
- B.
  
  Lipid enveloped viruses, Gram positive bacteria, Fungi, Cysts, Endospores
- C.
  
  Gram positive bacteria, small non enveloped viruses, Mycobacteria, Fungi
- D.
  
  Spores, Coccodia, Large non enveloped viruses, Gram positive bacteria, fungi
- E.
  
  Spores, Mycobacteria, Cysts, Gram negative bacteria, Fungi, Lipid enveloped viruses
Correct Answer
B. Lipid enveloped viruses, Gram positive bacteria, Fungi, Cysts, Endospores

Explanation
The correct answer is Lipid enveloped viruses, Gram positive bacteria, Fungi, Cysts, Endospores. This sequence is based on the susceptibility of organisms to disinfectants. Lipid enveloped viruses are the least susceptible as their outer lipid layer can be easily disrupted by disinfectants. Gram positive bacteria are next in line as they have a thick peptidoglycan layer that provides some resistance. Fungi are less susceptible than bacteria due to their unique cell wall composition. Cysts, which are dormant forms of certain parasites, are more resistant than fungi. Finally, endospores, which are highly resistant structures formed by some bacteria, are the most resistant to disinfectants.

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35.

Where human error is identified as the cause of a deviation, it is not necessary to consider if the error was influenced by the lack of a procedure to control the activity
- A.
  
  True
- B.
  
  False
Correct Answer
B. False

Explanation
This statement is false because even if human error is identified as the cause of a deviation, it is still necessary to consider if the error was influenced by the lack of a procedure to control the activity. The absence of a procedure can increase the likelihood of human error and therefore should be taken into account when analyzing the cause of the deviation.

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36.

Cleanrooms are measured for particulate counts at three different states: 'as-built', 'at rest' and 'in-operation'
- A.
  
  True
- B.
  
  False
Correct Answer
A. True

Explanation
Cleanrooms are indeed measured for particulate counts at three different states: 'as-built', 'at rest', and 'in-operation'. These three states represent different conditions of the cleanroom and help in assessing its cleanliness and effectiveness in controlling particulate contamination. The 'as-built' state refers to the initial state of the cleanroom after construction or renovation. The 'at rest' state refers to the condition of the cleanroom when it is not in use but is operational, with all equipment and systems in place. The 'in-operation' state refers to the condition of the cleanroom during normal operations, with personnel and equipment in motion. By measuring particulate counts in these different states, the cleanliness and performance of the cleanroom can be evaluated.

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37.

Starting material labels should include at least the following information:
- A.
  
  The designated name of the product and the internal code reference where applicable
- B.
  
  A batch number given at receipt
- C.
  
  Where appropriate, the status of the contents (e.g. in quarantine, on test released, rejected)
- D.
  
  All the above
- E.
  
  None of the above
Correct Answer
D. All the above

Explanation
Starting material labels should include at least the following information: the designated name of the product and the internal code reference where applicable, a batch number given at receipt, and where appropriate, the status of the contents (e.g. in quarantine, on test released, rejected).

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38.

Cleanroom Total Particulate Count measurement 'At rest' requires:
- A.
  
  Installation is cleaned and not operational (including equipment and HVAC) and no operating personnel are present
- B.
  
  Installation is installed and operating, complete with production equipment, but with no operating personnel present
- C.
  
  Installation is installed and HVAC operating with no operating personnel present
Correct Answer
B. Installation is installed and operating, complete with production equipment, but with no operating personnel present

Explanation
The correct answer is "Installation is installed and operating, complete with production equipment, but with no operating personnel present." This means that the cleanroom is fully set up and functioning, including all production equipment, but there are no people present in the area. This condition is necessary to accurately measure the total particulate count in the cleanroom when it is in a state of rest.

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39.

What is a clean room?
- A.
  
  An enclosed space in which airborne particulates, contaminants and pollutants are kept within strict limits. Within the pharmaceutical industry, clean rooms are used in the manufacture, industrial product or scientific research of products.
- B.
  
  They remove pollutants, particles and contaminants from outside ambient air. Outside air is initially circulated to a filter system. The filters (either HEPA or ULPA), then clean decontaminate the outside air according to their specifications. The filtered air is then forced into the clean room. Contaminated air within the clean room is forced outside the room vertically or re-circulates back into the filter, and the process starts again. Its an on going cycle.
Correct Answer
A. An enclosed space in which airborne particulates, contaminants and pollutants are kept within strict limits. Within the pHarmaceutical industry, clean rooms are used in the manufacture, industrial product or scientific research of products.

Explanation
A clean room is an enclosed space that maintains strict limits on airborne particulates, contaminants, and pollutants. It is commonly used in the pharmaceutical industry for manufacturing, industrial production, and scientific research of products. Clean rooms remove pollutants, particles, and contaminants from outside ambient air by circulating it through a filter system. The filters, either HEPA or ULPA, clean and decontaminate the outside air according to their specifications. The filtered air is then forced into the clean room, while contaminated air is either forced outside the room or recirculated back into the filter. This process continues in an ongoing cycle.

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40.

Cleanroom environments and PPE
- A.
  
  In cleanroom environments, humans are the primary source of contamination. 80 - 90% of normal microbial flora identified in a cleanroom environment, is generated by humans. Therefore, the use of PPE should be thoroughly utilised and good cleanroom procedures must be followed accordingly, in order to minimise microbial contamination.
- B.
  
  The use of barriers (e.g. sterile gloves / masks etc), equipment preparation, environmental controls are important guidelines to follow within the industry.
Correct Answer
A. In cleanroom environments, humans are the primary source of contamination. 80 - 90% of normal microbial flora identified in a cleanroom environment, is generated by humans. Therefore, the use of PPE should be thoroughly utilised and good cleanroom procedures must be followed accordingly, in order to minimise microbial contamination.

Explanation
The primary source of contamination in cleanroom environments is humans, as they generate 80 - 90% of the normal microbial flora found in these environments. Therefore, it is crucial to use personal protective equipment (PPE) and follow proper cleanroom procedures to minimize microbial contamination. This includes using barriers such as sterile gloves and masks, preparing equipment properly, and implementing environmental controls.

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41.

What is microbiological analysis?
- A.
  
  It helps to keeps under control the proliferation of viruses, bacteria and other microorganisms which may cause contamination and disease. It's the use of biological, molecular or chemical methods for the detection and identification of microorganisms in a material. It is often applied to disease causing and spoilage microorganisms.
- B.
  
  There are many factors affecting the microbiological analysis of pharmaceutical products, for instance: contamination, cross-contamination and contamination control processes.
Correct Answer
A. It helps to keeps under control the proliferation of viruses, bacteria and other microorganisms which may cause contamination and disease. It's the use of biological, molecular or chemical methods for the detection and identification of microorganisms in a material. It is often applied to disease causing and spoilage microorganisms.

Explanation
Microbiological analysis is the use of biological, molecular, or chemical methods to detect and identify microorganisms in a material. It helps to control the proliferation of viruses, bacteria, and other microorganisms that can cause contamination and disease. This analysis is often applied to disease-causing and spoilage microorganisms. Factors such as contamination, cross-contamination, and contamination control processes can affect the microbiological analysis of pharmaceutical products.

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42.

Sterility
- A.
  
  Sterility of a product suggests that it has complete absence of micro-organism.
- B.
  
  Sterility of a product can only be assured through a robust programme known as 'contamination control' this includes: terminal sterilisation and aseptic processing.
Correct Answer
A. Sterility of a product suggests that it has complete absence of micro-organism.

Explanation
Sterility refers to the complete absence of micro-organisms in a product. This means that the product has been thoroughly sterilized and is free from any potential contaminants. Achieving sterility requires a comprehensive contamination control program, which includes methods such as terminal sterilization and aseptic processing. These measures ensure that the product is safe for use and will not cause any harm or infection to the user.

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43.

4 potential contaminants affecting the sterility of a product
- A.
  
  Living / viable microorganisms = causes dangerous disease and can derive from normal flora.
- B.
  
  Inert / non-viable microorganisms = can be used to transport airborne organisms, it will therefore need to be tightly controlled in facilities such as cleanrooms.
- C.
  
  Pyrogens = are produced by bacteria and derive from endotoxins or lipopolysaccharides. They induce fever.
- D.
  
  Chemicals = occurs due to the improper removal or incorrect use of cleaning and disinfection agents. Its the mix up of raw materials.
Correct Answer
A. Living / viable microorganisms = causes dangerous disease and can derive from normal flora.

Explanation
Living/viable microorganisms can contaminate a product and affect its sterility. These microorganisms can cause dangerous diseases and can come from the normal flora present in the environment. It is important to control and prevent the presence of these microorganisms to ensure the safety and sterility of the product.

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44.

How to ensure sterility
- A.
  
  Quality control (QC), which s the approval of specifications for the release of raw materials and products, its utilised to ensure that all pharmaceutical products are sterile and meet required standards.
- B.
  
  Contaminants such as particles can also have a great impact on the sterility of a product as they are easily obtained. Particles can derive from dust, human flora (e.g. skin flakes), rubber, glass and also fibres from clothing. HEPA filters are then used to remove 99.97% of particles at 0.3 microns or larger.
Correct Answer
A. Quality control (QC), which s the approval of specifications for the release of raw materials and products, its utilised to ensure that all pHarmaceutical products are sterile and meet required standards.

Explanation
Quality control (QC) is an essential step in ensuring sterility and meeting required standards for pharmaceutical products. It involves approving specifications for raw materials and products, which helps to identify and eliminate potential contaminants that can affect sterility. Particles, such as those derived from dust, human flora, rubber, glass, and clothing fibers, can easily contaminate a product. To address this, HEPA filters are used to remove 99.97% of particles at 0.3 microns or larger, further ensuring the sterility of the pharmaceutical products.

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45.

What is disinfection?
- A.
  
  The destruction of microorganisms, not bacterial spores. It may not kill organisms but reduce it to a level deemed as acceptable nor harmful to health or products
- B.
  
  Biocide = chemical agents that kills microorganisms
- C.
  
  Antiseptics = a product with disinfectant properties used on the skin - it must be non- toxic and non- irritant.
- D.
  
  Preservative = included in pharmaceutical products to prevent growth and spoilage.
Correct Answer
A. The destruction of microorganisms, not bacterial spores. It may not kill organisms but reduce it to a level deemed as acceptable nor harmful to health or products

Explanation
Disinfection refers to the process of destroying microorganisms, excluding bacterial spores. While it may not completely eliminate organisms, it aims to reduce them to a level that is considered acceptable and not harmful to health or products. This process is different from sterilization, which aims to completely eradicate all forms of microorganisms, including bacterial spores. Disinfection is commonly achieved using biocides, which are chemical agents that have the ability to kill microorganisms. Antiseptics, on the other hand, are products with disinfectant properties that are specifically used on the skin and must be non-toxic and non-irritant. Preservatives are substances included in pharmaceutical products to prevent the growth and spoilage of microorganisms.

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46.

Definitions
- A.
  
  Fermentation = the alteration or production of products with the help of microorganisms.
- B.
  
  Non oxidising = QAC's (benzalkonium chloride), Biguanides (chlorhexidine) + Alcohols (ethanol)
- C.
  
  Oxidising = Chlorine, Iodine and Oxygen releasing compounds
- D.
  
  Sterility = condition of being sterile - lack of viability, no growth or reproduction
- E.
  
  Microbiologically = Complete absence of viable cells, spores and viruses - cells could be present as long as they are completely dead
- F.
  
  Aseptic = object/product that will not cause sepsis
Correct Answer
A. Fermentation = the alteration or production of products with the help of microorganisms.

Explanation
The correct answer defines fermentation as the process of altering or producing products with the assistance of microorganisms. This process typically involves the breakdown of sugars into alcohol or acids by yeast or bacteria. Fermentation is commonly used in the production of various food and beverages such as bread, beer, wine, and yogurt. It is an important process in the food industry as it helps to enhance flavors, preserve food, and produce certain desired products.

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47.

Definitions
- A.
  
  D value (decimal reduction time) = time taken at a fixed temperature or radiation dose required to achieve a 90% reduction in viable cells.
- B.
  
  Z value = the increase in temperature needed to reduce the D value of an organism by 90%
- C.
  
  Inactivation Factor (IF) = standard used post sterilisation *IF = 10^t/d
- D.
  
  Methods of sterilisation = Moist heat, Dry heat, Filtration, Radiation and Chemical/Gaseous
- E.
  
  Moist heat = solutions, dressings, glass/metal instruments + gloves Dry heat = dressings, glass/metal instruments Filtration = solutions, air/gases Radiation = dressings, needles/syringes + disposable instruments
Correct Answer
A. D value (decimal reduction time) = time taken at a fixed temperature or radiation dose required to achieve a 90% reduction in viable cells.

Explanation
The D value, also known as the decimal reduction time, is a measure of the time taken at a fixed temperature or radiation dose to achieve a 90% reduction in viable cells. It is used to assess the effectiveness of sterilization methods. The Z value, on the other hand, refers to the increase in temperature needed to reduce the D value by 90%. The inactivation factor (IF) is a standard used post-sterilization, and it is calculated as 10^t/d. The answer provided correctly explains the D value as the time required to achieve a 90% reduction in viable cells at a fixed temperature or radiation dose.

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Microbiology: Methods Of Sterilization Quiz Questions!

Which of the following is the best way of controlling contamination in a clean room?

Which of the following is most correct regarding alcohol hand rubs?

Which of the following groups of organisms produce endospores?

For an aseptically dispensed product, which of the following are critical control points as defined by HACCP principles

Which of the following is an eukaryotic micro-organism?

Which of the following is most correct when referring to types of contamination in a clean room?

When should the identification of micro-organisms discovered during monitoring be identified:

Members of the human microbiome are a significant problem/concern in contamination control as

Select the cell envelope component that is a pyrogenic endotoxin

Which of the following statements regarding contamination is true?

Which of the following groups of organisms produce endospores?

Which of the following lists of organisms produce endotoxins/pyrogens?

Which of the following areas of the body will possess the highest numbers of microbial cells?

The most widely used, effective, economical and reliable method of sterilization used in the health care setting is:

Resident skin bacteria are best described as

Which of the following is the accepted Sterility Assurance Level (SAL) for pharmaceutical products?

A pharmaceutical product contains 1 x 1012 cfu/mL, how many decimal reductions are required to reach the accepted SAL?

If a microorganism has a D60 of 0.5 minutes, for how long would you have to heat a suspension the microorganism at 60OC to achieve 8 decimal reductions of the cell population?

Which of the following statements about low temperature gas plasma sterilisation is correct?

Which of the following describes the Gram positive cell envelope structure?

Which of the following is a eukaryotic micro-organism?

Which of the following statements is false?

Which of the following organisms is an opportunistic pathogen that has been associated with contaminated eye drops and ointments

Which of the following are the obligatory test organisms in BSEN 1276?

Which of the following is an example of an oxidising disinfectant

Which of the following is a definition of disinfection?

Which of the following is/are included in the bactericidal disinfectant test (BSEN 1276) to simulate the presence of interfering substances?

Which of the following lists of organisms are sources of endotoxic pyrognes?

Which of the following is true of viruses?

Which of the following is the best description of chlorhexidine?

Which of the following describes acquired antimicrobial resistance?

Which of the following list of organisms are in the sequence from least susceptible to most susceptible to disinfectants?

Where human error is identified as the cause of a deviation, it is not necessary to consider if the error was influenced by the lack of a procedure to control the activity

Cleanrooms are measured for particulate counts at three different states: 'as-built', 'at rest' and 'in-operation'

Starting material labels should include at least the following information:

Cleanroom Total Particulate Count measurement 'At rest' requires:

What is a clean room?

Cleanroom environments and PPE

What is microbiological analysis?

Sterility

4 potential contaminants affecting the sterility of a product

How to ensure sterility

What is disinfection?

Definitions

Definitions

A pharmaceutical product contains 1 x 10¹² cfu/mL, how many decimal reductions are required to reach the accepted SAL?

If a microorganism has a D₆₀ of 0.5 minutes, for how long would you have to heat a suspension the microorganism at 60^OC to achieve 8 decimal reductions of the cell population?