so we are talking about chapter six which is all about infection welcome to the video lecture so chapter six um first we to talk about microorganisms kind of what that is um just basically very small living forms um you should know it's a need to know the four types of microorganisms they are bacteria fungi viruses protozoa um big focus on what causes most infections for us humans is going to be bacteria or viruses uh we can grow them in an artificial culture medium that's how we do cultures looking for bacteria growth and then figuring out what antibotic they might be sensitive to that sort of thing um and they kind of have two categories technically non-pathogenic um usually don't cause disease but we'll talk about non-pathogenic means doesn't mean they can't cause a disease um part of our normal Flora we'll talk about that definition um and often that bacteria is beneficial your best example is that is that um we have tons of different types of bacteria that live in our gut in our large intestine the small intestine that help us digest our food and process waste and those would be called normal flora and they usually don't cause infection but they can pathogens would be microorganisms that are disease causing um this is a chart that's on the breakdown this chart is just B basically talking about the types of microorganisms and what their shape their cellular shape looks like this is not something you need to know this is definitely more uh of a very indepth disease pathology here I don't think we're at that need where we need to know all this stuff but you'll see some of these the caucuses like stre of caucus basilis staff strapo right you can see the different shapes and and kind of what their functionality is basically their shape and how they attach cells and how they reproduce is kind of the difference in microorganisms so first the kind of King of the castle with this is bacteria um there's some classifications to bacteria um Pro carot types and ecotypes proar types um is where is is like basically a cellular shape bacteria fall in the category of proar types um they have no membrane around their n um they have no nucleus they reproduce they the what's difference with bacteria they have a very complex cell wall structure typically and a lot of bacteria do not require living tissue like they don't have to have the host to survive so right now there could be bacteria on your your countertops in your kitchen and animate objects living and thriving they don't necessarily have to have a living host or living tissue to survive and they have very a lot of variations in shape and size um spores a little sidebar here some bacteria produce spores um your big your biggest example in healthcare is a bacterium called claustrum defil or shorthand CI uh forms some uh spores basically are a dormant latent form of the bacteria and these spores are basically like not dead bacteria but just a latent non reproducer form that can live on inanimate surfaces for minutes hours days even um long period of time survival and then highly resistant to heat and disinfectant so there if you seen in the hospital there's thing called bleach wipes that we use sometimes this is bleach wipes are the only thing are going to kill the Spore that SEI forms um or classic uh hand hygiene with soap and water not alcohol so very resistant um and that's why it makes C diff so easy to spread uh so viruses they're much smaller they're more of intracellular parasites basically viruses do come in shapes and sizes but uh small shapes and sizes um but they're a lot smaller than bacteria that's their main difference um and V viruses are basically categorized um on what kind of their what kind of nucleic acid they use so they might use um DNA and RNA to kind of make up their structure um it depends on that how they're classified but that also depends that'll dictate how a virus replicates um so what viruses do is they attach to our host cells where bacterium will maybe take over a host cell or destroy it take its place viruses are much smaller in about penetrating our cells and um basically messing with our cell genetic makeup and with in through the cell the viral DNA or RNA takes control they basically kind of pure Guist you know for lack of better viruses kind of poltergeist our cells and take them over and then use all the our cellular functions to produce more viruses so they basically take our processes to make protein and manage our cell and they're going to make new viruses or more of themselves from that and then they get released basically by causing lces causing cell destruction of the host cell or by attaching to other cells and moving across the membrane so there viruses are infectious um and very very powerful this is kind of showing viral replication if you want to summarize it virus attaches and penetrates our cell wall gets to our nucleus um basically takes over the RS um takes control of our host C DNA and then uses those mechanisms to make copies of itself make new viruses and then release them and that's where you get an infection so Laten viral infection so talk about what Laten kind of means um this means that a virus potentially we get infected with a virus it enters the cell it's producing its its proteins um it may stimulate a immune response but they NE necessarily don't so they may this latent viral infection means we get a viral infection that can stay with us uh but doesn't always cause an immune response all the time because if it's more latent and not as active but has like active moments and flare ups and then there will cause an immune response the the herpes virus is this way herpes zoster is technically what we get from chickenpox and then it stays dormant for a long time and then when we get older it starts to rear its head again or imun response and that's where you get shingles so there's some viruses that are latent viral infections or dormant they can stay once we get it will have it forever it may not always cause symptoms but it will cause like flareups um the thing with viruses too that make them so hard to treat is that they mutate often because they're basically just a small uh molecule that needs a host to live they're always their their DNA or RNA structure is always mutating and so in that that respect keep in mind that some viruses can mess with the host cell's DNA and therefore it could cause mutation in our DNA which could lead to cancer development so certain viruses are known to be more uh hard harder on our own host cell DNA on our cell's DNA and then lead to greater risk of certain types of cancer in the future so viruses are tricky tricky bugs um fungi they're UK carot organism that means they contain a nucleus um the other bacteria don't contain a nucleus um you're going to find fungi throughout our environment it's going to live on animals uh certain plants and some foods you know technically mushrooms fit in that category um it could be kind of a mold infection a yeast infection would be fungi um only a few guy are generally pathogenic or um causing infection basically um typically there's a couple that are going to cause usually primary skin or mucous membrane infections um typically you're only going to see I think the need to know from fungi just to say that typically you're not going to see a systematic like a whole systemic response to a fungal infection like a fullon pneumonia or something like that unless that particular individual is had their immune system suppressed or compromised for some reason um typically we live and breede you know fungi all day every day we coexist fine um typically not a always a pathogenic agent um some examples uh Tina petus aaia Pettis or petus is athletes foot fungi that happens and fungi like moist environments um and they're usually again what we would call opportunistic I'll mention that in a second but uh candida um Can calls this citis citis is a localize yeast infection again most of the time you're not going to see fungal infections unless someone's been had a bacterial infection that were just hammering them with um lots of antibiotics sometimes this can cause fungal infections to rear up kind of take the place of the bacteria we've killed because we've killed off some good bacteria um and that would be what you call OPP T un istic this is a picture of oral citis this is also known as thrush have you ever heard of thrush this is a very common development of again cantis a yeast type fungi that lives in her mouth normally doesn't cause any problems um but it can cause some ulcerations and some sores called thrush if we had extensive antibiotic treatment kind of throwing that all off um other agents of disease technically this is not one of the big four um helmets or helminths um these are round worms flat worms um they are parasites um and they enter their body through usually indigestion or other things this is usually going to be really odd different foreign um foods that are kind of riddled with parasites uh drinking water that's unclean that has parasites that sort of stuff um infection can be life-threatening but some people can live with these flat worms or round worms and not even know it if their immune system is working okay um so just to kind of categorize the helmouth um diseases you got pin worms hookworms tapeworms some of us have probably heard tapeworms before but um pin worms are in dust and like really um terrible breathing living condition places children more susceptible hookworms um uh you're going to think like fecal contaminated soil so hookworms might come from manure and stuff like that and then tapeworms are usually from uncooked pork uncooked Meats so think of the helmouth think of hell because they're worms and that's carry as hell I guess if you want to think of it that way um so resident flora what does this mean so like typically this term is what I mentioned before normal Flora we have normal microorganisms especially bacteria that hang out in our body like in our gestive tract especially mucus membranes mouth nose and they do a job for us I mean they um help um must promote and they digest things that our body can't digest and help us get rid of waste and that sort of thing um and this is a normal thing so think of skin nasal cavity mouth or gut so all the GI track basically urethra technically vagina for women um are going to have a a what's called a termed a normal flora Flora just being like variety of microorganism is what Flora is talking about so that's a need to know you need to hear normal flora and kind have a general idea what's talking about there um principles of infection again kind of infection in general is an organism some kind some kind of microorganism is able to get into the body and reproduce in our body's tissues um we can again have that normal floor around but as soon as it starts multiplying inside of one of our tissues that's now an infection um and then some names with this we talked about this in chapter one you have sporadic endemic epidemic pandemic is kind of the sporadic means there's just single cases happening around an area endemic means that um there's a certain population like a community that has had a disease uh epidemic means that it's just higher than normal like if I compare again epidemic would be like if I look at Middle Tennessee and I say there was a you know I'm just making up numbers but there was a 100,000 people that got the flu last year and now this year in 202 five or you know 2024 or whatever there's 125,000 uh maybe that's not the best I mean 150,000 so that could be uh epidemic like scale of um um uh transmission of a disease and then pandemic would be multiple regions across the globe would be pandemic so how do we trans transmit this infection from person to person well some names some terms that are worth highlighting so a lot of these terms are going to be neat to know guys okay so terms are going to be need to know so you have Reservoir so you have Reservoir this is where the infection starts the source of infection this could be a person that has an active infection this can be a person who is asymptomatic but whoever started this is a reservoir a carrier the difference is the Carri carer is a person who may never develop the disease but is still a carrier for it so they are the source of infection but they didn't have an active infection at all they just happen to be someone that carries this disease that is communicable that is transferable basically subclinical signs they don't really have any signs of infection at all not necessarily asymptomatic they just don't they don't have anything at all that indicates disease um and some people will have this some viruses act this way so how do we uh transmit infectious agents so basically when we talking about this it gets all Espionage and and cool so talking because we talked about an agent is whatever microorganism is causing the infection again Reservoir environment or person that contains this infecting agent so the environment the soil the food uh or the infected person or animal um is the reservoir for the agent and so they may show no signs or symptoms of disease or they may show no signs of sympt disease so I best I think just stick with reservoir for now as kind of that will progress the transmission the transmission process so Reservoir starts may have symptoms may not they're uh someone that has a disease port portal of exit means that that's how it left the reservoir so if I cough something like that that would be the portal of exit for this uh transmission of this pathogen or the portal of exit is how it left my body so if it left for my ma my mucus membrane my mucus secretions that would be portal of exit Moto transmission is the method in which that infection infectious communal agent reaches the next person so if it got to them by water or air like I from the air that I was breathing and they got close to me they got it or if they drink after me water direct contact like physical touch sexual intercourse uh and then food would be the mode of Transport or Transportation excuse me a mode of transmission of a pathogen so you have like kind of fall in the path you have you have someone that's um right you starting of your Reservoir you've got someone that's a portal of exit meaning how did it leave the reservoir motor transmission is how did it get to the next person portal of entry is how did it access the new host it went through their Airway it went through their scan it was through their GI track what's the portal of entry and then susceptible hosts it just means someone that is susceptible susceptible means likely to um catch a particular disease and this depend a lot on their age their nutrition level health status how functioning is their immune system that kind of thing so if we break down modes of transmission and we just take that subset about water air food that sort of stuff modes of transmission of how we got pathogen to um someone else how would we break that down we'd have direct contact means there's nothing in between us so this has to be touching sex activity contacted with infected blood bodily secretions direct contact indirect means there's intermediate object or organism in between this so contaminate a hand just because a hand that's no open wounds or anything that hand is on exterior of the body um food um fomite is technically a word it's not a stressful word to know about it just means an animate object so if it's ctive Spore it's on the counter no one cleaned the they didn't clean the blood pressure cuff after using it on a CIF patient that has the spores on it now the blood pressure machine has become a vector for a transmission of disease and it's an inanimate object it's a fomite then that's how that's an indirect contact so other things these are the need to know from this mode of transmission these are going to be the most um uh compatible with you working in hospital settings something like that so because these relate to how you treat a patient and that sort of stuff so you have droplet transmission so droplet transmission is uh directly from someone's respiratory salivary track respiratory tract saliva direct secretions are expelled so like if you don't notice if you're going to watch this slow-mo video when we talk to each other we're spitting all the time so if I'm in front of room talking to you guys unfortunately you're probably getting some micro drops of my spit on you just sitting in the front row you're welcome I know that's gross but that is true when we have close conversations with people transmission is going to be droplets of our mucus and spit saliva and that could transfer so droplet transmission aerosol means that it's in small small microscopic particles in the air and this is comes through the respiratory tract but it's in the air and moves that way so this can go further than droplet precaution so aerosol means it can go further this is where you need an n95 respirator uh distancing that sort of stuff and then Vector born means there's a vector or something that carried it uh so it's basically an intermediate host so an insect or animal so Vector born example is malaria and mosquito um tick born illnesses uh with deer and other animals like that that's a vector born ill this rabies Vector born um no uh excuse me noomi no soomal infections are basically occur in healthc care facilities so nomial infections occur in healthc care facilities this is need to know no soomal infection Health Care Facility infection not great again Health Care Facility what does that mean hospital nursing home doctor's office dental office anywhere that performs Healthcare chiropractor you know whatever uh 10 to 50% of all patients acquire infection uh in in a nomial infection in this way basically especially in a hospital setting there is a lot of microbes because there's a lot of sick people um there's also patients there with undiagnosed infectious diseases a shared environment especially in nursing homes with maybe double rooms that sort of thing uh and then a lot of treatments we do May weaken or suppress someone immune system which makes them more susceptible to infection and many healthcare workers and fomites and add objects like that blood pressure machine are going to act as reservoirs for um the infection especially we're not following proper procedures so factors that decrease host resistance um age always think opposite ends of the spectrum if we're talking about newborn huge risk really underdeveloped immune system older adult huge risk um really declining immune system productivity pregnancy it takes a lot of energy to grow a baby a lot of things are going on so pregnancy is going to make you more susceptible just genetic immuno deficiency if they have a disease that causes their immune system to weaken or they're taking medications that affect their immune system um poor nutrition any chronic illness diabetes hypertension um heart failure heart disease um so severe emotional stress or PTSD physical stress you know severe workouts military training stuff like that inflammation or anything that messes with inflammatory responses are going to be it so think really young really old pregnancy chronic diseases is probably your big three from this factors so again young old pregnancy uh chronic diseases and then impaired immune system response so when it says the resistance of host to infections which of the following factors is not typically considered a contributor to decreased host resistance so what would not be a contributing factor so I give you a second to think about that if you answer number one you're right it's inadequate nutrition that typically is a factor so adequate nutrition would not be so again those those not questions to get you sometimes control of transmission basically there's two approaches you have to have you have to have standard precautions for everybody so this is used in most Healthcare settings at this time standard precaution means we use the same type of precautions with any client any patient you come in contact with so basically you treat everybody in healthcare setting like you're going to come in contact with fluid that can be a vector for transmission of disease so even if I'm going in there to just you know put some ice in the patient's water uh picture or whatever wear gloves hand hygiene before and leaving the room these are standard precautions that have been hardcore proven to limit the transmission of disease um specific precautions would be those diagnosed with a particular disease this would be things like I talked about droplet precautions is one airborne precautions droplet would mean wearing a mask um airborne mean they may need a pressure pressurized room um that has positive air pressure they may need we may need to wear n95 respirators that sort of stuff and then the other thing the way that we kind of prevent the spread again control transmission is we got to break the cycle basically um find the reservoir whether that's a fomite or whether that's a person um isolate them um figure out where the the source is um and then other things we do restrict access to contaminated Foods contaminated water reduce the contact between infected people block those exit entry portals so keep it in mind what could be an exit point for someone's um someone could be a a vector for find the exit and make sure the entry for other people's protective mess with those modes of trans uh transmission by following un uh standard precautions and then make sure we're practicing good health care nutrition health care support immunizations Wellness checks that sort of stuff at other things that are fairly obvious adequate cleaning of the surroundings um disinfectants antiseptics bacterial sprays the hand soap washing your hands all these sort of stuff kind of wrapping up here the physiology of infection um this was talked about I think earlier one of the chapters but it's good to note again we have an incubation period incubation so these are neat to know incubation period is the time between the organism kind of point of entry into the body and then the until we have a signs of the disease varies very differently depending on the microorganism at work here so that's incubation time we become uh now um basically for the disease um until we show symptoms predal is going to start having symptoms that are pretty consistent I feel malaise I feel off fatigue anorexia headache and then acute period is infectious disease develops fully so full symptoms that are consistent with whatever disease it is um that's an acute period but for a lot of um [Music] microorganisms the incubation period can still be transmitted to another host and so that's why some infections get spread so far um other signs and symptoms of infection local inflammation there's your pain swelling redness drainage maybe um systemic it's your fever Mala headache maybe some nausea um elevated white blood count possible and how do we diagnose well we could do a a culture of urine of blood to look to see what organisms grow um there's drug sensitivity test um blood test that would really tell us about infection is going to be our white blood cell count so lucco cytosis these are need to know for blood test lucco yosis um means elevated white blood count typically you're going to see this a lot with bacterial infections lucenia means a lower white blood cell count you likely see this more viral infections as they infect host cells again we can do a bunch of counts on the immature white blood cells that sort of stuff tells the doctors a lot of information and then C reactive protein and ESR are in line with measuring systemic inflammation which could kind of go yes again inflammation could have it but if I think I have an infection if I have tests that come back for systemic effects of inflammation then I'm probably confirming an infection right um there's also immunological testing identifying antigens um looking for antibodies for a specific disease and seeing if you're immune to it that sort of stuff so that would be chapter six about infections now we're moving on to chapter seven which is about our immunity and again these all chapters five six and seven are all very very closely related here so hang in there uh we're going to move on