Introduction to Controlling Microbial Growth

in this video, we're going to begin our introduction to controlling microbial growth. And so it's actually really important for humans to be able to control the growth of microbes. And this is because controlling microbial growth is actually critical to human health and a wide variety of other processes. For example, the manufacturing of specific types of products and even specific types of foods that you may eat on a regular basis. And so uncontrolled microbial growth is actually a problem because it can lead to increased risk of disease and it can lead to the spoilage or the reduced quality of specific types of products. And so once again, it is really important for humans to be able to control microbial growth. And so it turns out that there are actually many different types of processes that humans can use to control or limit the growth of microbes and these processes that humans use to control or limit microbes. They can either be physical processes, yeah, chemical processes or they could be a combination of both physical and chemical processes. And so moving forward in our course, we're actually going to talk about a lot of different types of processes, both physical and chemical that humans can use control microbial growth. And so because there are so many different types of microbial growth control methods, it's also important that scientists know how to select a specific process of microbial growth. And selecting a process of microbial growth control depends on many variables, including the circumstances and the level of control that is required. And so later in our course will also get to talk more about the process of selecting the appropriate microbial control method. But if we take a look at our image down below, we can see a map of our lesson on the processes of controlling microbial growth. And so this image does serve as a map or an outline of our lesson, moving forward and so notice that the title here is microbial growth control methods. And immediately the growth control methods are broken up into being either physical methods such as temperature and filtration, or they're broken up into being chemical methods such as liquid chemicals and gas chemicals. And then what we have right in the middle here is irradiation, which is really a combination of both physical and chemical, since irradiation can lead to direct damage, but it can also lead to the formation of other chemicals that end up causing damage uh to the cells. And so we'll be able to talk a lot more about each of these different types of microbial growth control methods as we move forward in our course. And so in our course moving forward, we're going to explore the left most branches first. So we'll cover the physical methods of chemical control which include controlling temperatures such as using moist heat, dry heat or refrigeration uh And also filtration such as filtering liquids and also filtering air. Uh Then we'll get to talk about irradiation and the radiation is somewhat of a combination of physical and chemical methods since irradiation can cause direct damage or it could lead to the formation of chemicals and those chemicals end up causing the damage. And so um Irradiation is an example of something that would be considered a combination of physical and chemical control. And there are different types of a radiation that we'll get to talk about moving forward such as ionizing radiation as well as non ionizing radiation such as UV ultraviolet light. Which again we'll get to talk more about moving forward. Then after we cover the physical methods and irradiation we'll move on to talking about the chemical methods in our lesson, we'll talk about the liquid chemicals first and then we'll talk about the gashes chemicals. And so once again, this year is just our introduction to controlling microbial growth. And moving forward. We'll be able to talk a lot more about all of these different types of methods and we'll also talk about how to select the appropriate method. And so this year concludes our brief introduction and we'll be able to apply these concepts and learn more as we move forward. So I'll see you all in our next video.

Why is it important to human health and wellbeing that we control microbial growth?

• A. Uncontrolled microbial growth can lead to increased risks of disease and infection.
• B. Uncontrolled microbial growth can lead to spoilage of food products.
• C. Uncontrolled microbial growth can lead to contaminated experiments.
• D. All of the above.

Physical methods used to control microbial growth include all of the following except?

• A. Refrigeration.
• B. Air filtration.
• C. Liquid chemical disinfectants.
• D. Steam (moist heat).

So when it comes to controlling microbial growth, there's actually a lot of terminology that is used. And so in this video we're going to introduce some of the terminology of microbial growth control. And so there are several terms used in relation to controlling microbial growth, including these terms that we have listed down below, which are decontamination, sanitization, disinfection, sterilization and preservation. And so the first term on this list is decontamination. And decontamination is a really broad or a really general term that refers to the overall reduction of the number of pathogens or disease causing agents to a safe level. The next term that we have here is sanitization. And sanitization is a more specific term that refers to cleaning and reducing pathogens in order to specifically meet accepted public health standards in order to help minimize disease. And so when it comes to the term sanitization, what we've found is that things that have been sanitized are going to have the appearance of being clean. And so there's not going to be a lot of dirt or oil on something that has been sanitized, it's going to have the appearance of being clean and it's going to be reducing pathogen similar to decontamination, except sanitization is also going to be unique and that it is going to be meeting accepted public health standards. And so that means that it's going to be somewhat less toxic to humans in comparison to some of the other things that might be causing some of these other terms. So next, what we have on this list is disinfection, and disinfection is going to be the elimination of most, but not all pathogens. And again, pathogens are just disease causing agents. And so what this means is that through disinfection, because only most pathogens will be eliminated, it is possible for some viable or some living microbes to remain after disinfection. And so that's important to keep in mind because this is really what distinguishes it from sterilization. And that's because sterilization is a term that refers to the elimination of oh microbes except for prions, which prions are going to be these pro tenacious these protein infectious agents. Um but pretty much all other microbes such as microorganisms, viruses and even endo spores which tend to be resistant are going to be eliminated through sterilization. Whereas with disinfection again, most pathogens are eliminated but some viable microbes may remain, especially ones that are resistant such as endo spores for example. Uh And then the last time that we have on this list is preservation and preservation is the process of delaying rather than killing cells. It's the process of delaying the spoilage of perishable products usually by delaying the growth of microorganisms. And so perishable products are simply products or items that are likely to go bad quickly. And so preservation is just going to delay the spoilage process rather than eliminate the spoilage process. And so moving forward in our course will be able to talk about some methods of preservation. But if we take a look at this image down below, we can get a better understanding of each of these terms that we've discussed up above, starting with decontamination, which like I said before, is a really broad and general term that just refers to the reduction of the number of pathogens to a safe level. And so it can be used very broadly in many different scenarios. However, the terms that you see down below are a bit more specific terms that fall under decontamination. Uh sanitization is going to be reducing the number of pathogen specifically to meet public health standards and that's going to help minimize the spread of disease. And so notice that things that have been sanitized, like sanitized tables here are going to reduce the number of pathogens to public health standards. Therefore they're going to be less toxic to humans and they're going to have the appearance of being clean. And that's why we have these little sparkly clean, shiny uh in our image, just showing you that sanitized objects are going to have that appearance of being clean and meeting public health standards as pathogens are being reduced. The next time that we have here is disinfection and disinfection again is the elimination of most pathogens. And so notice here that we're, this scientist is using a disinfectant and the spray bottle here and notice that most pathogens are being eliminated here. However, some are still capable of surviving. And so uh disinfectants are going to be a little bit more toxic to humans in comparison to sanitizers. Um then what we have over here are is sterilization and sterilization refers to the elimination of all microbes except for prions of course, which are going to be very resistant. Pro tenacious infectious agents, but pretty much everything else is going to be eliminated through sterile ence or sterilization processes. And so here we're showing you specifically radiation being used as a sterilization techniques and notice that all of the microbes here have been eliminated. And so that is one difference between sterilization and disinfection. Disinfection again allows for the potential survival of some microbes, but sterilization pretty much kills all microbes. Now the last term that we have over here on the far right is preservation, which again refers to the delaying or just delaying spoilage of perishable products or products that are likely to go bad such as food for example. And one way to help preserve our foods, help them last longer is through the use of refrigerators and refrigeration. And so as we move forward. In our course, we're mainly going to be talking about methods of controlling microbial growth through disinfection as well as through sterilization. Those will be the two main types of methods that will talk about moving forward, but we will also talk a little bit about preservation techniques as well. And so this year concludes our brief introduction to some of the terminology of microbial growth control and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.

in this video, we're going to talk about the hierarchy of the microbial growth controlled terminology that we introduced in our last lesson video. And so notice on the left over here, we're showing you a pyramid. And these terms over here are focused on killing microbes or the elimination of microbes. And notice that decontamination is the very first term towards the top of this pyramid. And that's because we're called decontamination is a very broad or general term, which is why it's up here towards the top of our pyramid, showing that it is a broad term and it refers to the reduction of pathogens to a safe level. Next, what we have is sanitization, which is really a form of decontamination, but it is specifically going to allow for meeting public health standards and giving the appearance of the object being clean. And so because it's meeting public health standards, it is going to be somewhat of a more specific term than decontamination is. And so that's why it's given a more narrow region of the pyramid here because it's a more specific term. And then next, what we have is disinfection, which recall disinfection is going to eliminate most pathogens. However, it is possible for some pathogens to survive. And so notice that most pathogens are being eliminated or killed here. But some pathogens like this little guy over here may still survive after disinfection. And then the last time that we have here in this pyramid is sterilization and sterilization is going to eliminate all pathogens, all microbes except for prion. That's the only exception there. But everything else is going to be completely eliminated through sterilization techniques. And so you can see the percentage of microbes that survive is actually decreasing as we go from top to bottom in this pyramid. And so notice that with sterilization, because it's towards the bottom here, that there's going to be a very small percentage of microbes surviving practically 0% surviving uh through sterilization. Then notice that off to the right, what we have is uh processes that delay microbial growth. And so when we're talking instead of killing microbes, uh there's also the ability to delay the growth of those microbes. And really that is what preservation techniques are going to do uh instead of actually killing microbes, preservation techniques are going to delay the growth of microbes. And so hopefully this image here helps with your understanding of these microbial growth control terminology. And we'll be able to get some practice and learn more about these terms um and different microbial growth control procedures as we move forward. So I'll see you all in our next video.

What is the main difference between preservation and sterilization?

• A. Preservation does not kill microbes but delays microbial growth. Sterilization kills all microbes, except prions.
• B. Preservation preserves food by killing all microbes present in or on food. Sterilization kills most pathogenic microbes.
• C. Preservation reduces pathogens to meet health standards. Sterilization kills all microbes.  
• D. Preservation kills all microbes except prions. Sterilization kills all microbes, including prions.

in this video, we're going to talk about some different situations that warrant different levels of microbial growth control. And so the methods that are used for microbial growth control very greatly depending on the specific situation and depending on the specific level of microbial growth control that is needed. And so really the most important message that we're trying to communicate in this video is something that may seem pretty obvious and that is that the control measures that are used on a regular basis at your home may not be adequate enough for a surgery room in a hospital. And so once again, different situations or different scenarios are going to require different levels of microbial growth control. And so down below in our image, we're showing you five different situations or scenarios that can require different levels of microbial growth control. The first situation or scenario is going to be your daily life. And so things like washing using soaps and detergents and also cooking and refrigerating foods are all methods to be able to control microbial growth. And so you can see washing hands and doing laundry with soaps and detergents and cooking and refrigerating your foods are all methods that you can use at your home to control microbial growth. However, in a different setting such as a hospital setting, there are going to be different measures to control microbial growth. For example, sterilizing uh surgical equipment and operating rooms in order to avoid what are known as healthcare associated infections or H. A. I. S. For uh for short. And so healthcare associated infections or H. A. R. S. Are pretty much what they sound like. These are infections that a patient can get in a healthcare setting if the hospital does not control the microbial growth appropriately. And so it's really really important for hospitals to make sure that they create a sterile field for surgery and surgery rooms or operating rooms. And it is also important that they use um steam using instruments such as autoclaves to sterilize their surgical tools so that they don't accidentally cause a health care associated infection or an H. A. I. And a patient. And so the microbial growth control methods used in a hospital need to be a lot more stringent, a lot more rigid, a lot more powerful than the control methods that you may use in your daily life. Now, another setting that we have here is food production facilities that are going to use physical and chemical methods for food preservation, helping to delay the spoilage of perishable objects such as food products. And so here we're showing you an image of how pasteurization can be used in milk to kill microbes, found milk. And here we're showing you some vegetables that have been irradiated, some fruits and vegetables that have been irradiated or undergone radiation. And so this is a symbol here that represents uh food that has undergone irradiation. Uh And once again, the radiation may be something that you do not use in your typical daily life. So every scenario may require a different microbial control method. The 4th one that we have down here is going to be the water treatment facilities which are going to need to use specific disinfectants. uh and they will need to disinfect the drinking water to prevent waterborne illnesses. And so here is a water treatment plant uh and Deer Island. Uh And once again, the microbial control methods that they use in this water treatment plant may be different than the control methods that they use in any of these other situations. And then last but not least. The fifth scenario that we have here are going to be the laboratories and uh the laboratories such as scientific laboratories, microbiology laboratories, biology, laboratories. Um They also need to sterilize equipment uh In many scenarios they sterilize their equipment and they can use what is known as aseptic technique, which is a set of techniques that help to prevent contamination. And so down below here we're showing you a scientist and a covid 19 lab studying Covid 19, the virus that causes covid 19 and they're using PPE or personal protective equipment that protects the scientist. So notice that they have this coat and they're using gloves and they have a mask and goggles. Uh And so these are also ways to help you know uh control microbial growth to make sure that it's not being spread into other areas that it's being contained in a specific region. Uh And then over here what we're showing you is UV light ultraviolet light which can be used to help kill microbes in the lab and prevent contamination. And so basically what we've shown you here are five different situations that weren't different levels of microbial growth control. And so that is definitely going to be a consideration in selecting the appropriate control method. And so we'll be able to learn a lot more about selecting a microbial control method as we move forward in our course. But for now this year concludes our lesson and we'll be able to get some practice moving forward. So I'll see you all in our next video.

Which of the following concerning the varying levels of microbial control is false?

• A. We clean and sanitize our homes to reduce the number of microbial pathogens.
• B. Hospitals attempt to sterilize and kill all microbes in rooms and on tools to prevent infection.
• C. Pasteurization and irradiation are common microbial growth control methods used in food production.
• D. Laboratories sterilize media and tools to prevent contamination of their experiments.
• E. All of the above are true.