Question | Answer |
What is a biofilm? | Group of the same or different microorganisms adhering to a surface and each other |
Name four reasons microbes form biofilms: | Protection, fixes bacteria in nutrient rich locations, allow bacteria to live closely associated, strength in numbers! |
What two things does a biofilm protect bacteria against? | physical forces and predators |
What is an ecosystem? | The interaction of environment and organisms as a functional unit |
What is ecology? | the study of the interrelationships between organisms and their environments |
What is soil composed of? (5) | Inorganic mineral matter, air, water, organic matter, and living organisms |
What is microbial ecology? | study of microorganisms in their environment |
Where do microbes in soil grow? | On soil particles and on plant roots |
What is the Rhizosphere? | the soil that surrounds plant roots |
Why are microbes so important for soil? | They are important for soil fertility |
Name the three layers of soil in descending order: | Layer of undecomposed plant material, surface soil, subsoil |
Which layer of soil has the most microbial activity? | Middle level - surface soil |
Who is Selman Waksman? | An undergraduate student who 100 years ago counted how many bacteria where in the soil |
What is the main task of microbes in the soil? | decomposers |
What is composting? | a natural microbial process where microbes decompose organic materials into a dark, crumbly, earthy smelling soil conditioner |
How can composting save money? | reduces fertilizer and water use |
How is composting good for the environment? | reduces volume of garbage |
Does composting increase or decrease the temperature? | increase |
Why is it important to turn your compost pile? | Composting is an aerobic process |
What is the built environment? | includes all the physical parts of where we live and work |
What is an indoor ecosystem? | The microbial ecology of buildings |
What is the human microbiome? | the collective sum of all microbes, bacteria archaea, fungi, other eukaryotics, and viruses living on humans |
Why did scientists expect to find more genes when mapping the human genome? | because the rest of the excess genetic material was from the human microbiome |
Which is more likely to resemble each other: the microbial population of your mouth and your vagina or your mouth and someone else's mouth? | mouth and mouth |
How can people have different populations of microbes? | the microbial metabolic functions matter more than the species of the microbes providing them |
When does the microbiome first originate? | usually after birth but microbes have been found in utero |
why are cesarean babies more susceptible to disease? | They do not receive the same microbes as babies that exit the birth canal |
Why does the diversity of vaginal bacteria change in the first semester of pregnancy? | lactobacillus johnsonii becomes the dominant species because this microbe will aid the baby in the digestion of milk |
What is eradication? | reduction of an infectious disease's prevalence in the global host population to zero |
Why is it more dangerous to be isolated from microbes? | It raises the risk of infection and disease because a diverse microbiota in early life is required to have a proper immune system |
What is a probiotic? | a live microorganism that may confer a health benefit |
What is a prebiotic? | a non-digestible food ingredient that promotes the growth of beneficial microorganisms in the intestines |
What is a synbiotic? | nutritional supplements combining probiotics and prebiotics |
Who was Elie Metchnikoff? | The first person to observe the positive role of bacteria in the gut |
When was the term "probiotics" first used? | 1953 - to contrast antibiotics |
What is an antibiotic? | chemical substance produced by microorganisms and have the capacity to inhibit the growth and destroy other microorganisms |
What are antibodies? | blood proteins produced in response to a foreign substance they specifically recognize and mark for destruction |
What is a dietary supplement? | a product intended for ingestion that contains a "dietary ingredient" intended to provide nutritional value (not FDA approved) |
Is there clinal evidence that probiotics work? | no |
What is a chemostat? | a bioreactor where organisms are constantly fed and some culture liquid is removed to keep volume constant under controlled conditions |
What is a huge problem in dietary supplement testing? | contamination |
How can you deliver a diverse population of gut microbes straight to the gut? | fecal transplant |
What is sterilization? | the killing or removing of all viable organisms |
What is decontamination? | the treatment of an object to make it safe to handle |
What is disinfection? | removal of pathogens - not necessarily all microorganisms |
What is antisepsis? | removal or inhibition of microorganisms on body surface/ living tisse |
What is heat sterilization? | a widely used method to sterilize media and equipment |
What is pasteurization? | reduces the microbial load in heat sensitive liquids - does not kill all microbes |
What kind of radiation can reduce or eliminate microbes? | gamma rays |
What is the most important group of antibiotics? | B-Lactam |
What is the problem with antiviral drugs? | viruses only use host machinery (ribosomes) so it is difficult to target viruses only |
What is the problem with antifungal drugs? | fungi are eukaryotes like us so they are hard to target |
What do fungi cells have that human cells don't? | a cell wall |
What is the problem with antimicrobial drugs? | some organisms are naturally resistant to a given antimicrobial |
What is epidemiology? | branch of medicine dealing with the control of diseases and other factors relating to health |
What is a host? | any organism harboring a pathogen |
what is a pathogen? | organisms living on or in the host causing disease |
What is disease? | damage or injury to the host caused by a pathogenic microbe |
What is infectious disease? | disease caused by a pathogenic microbe |
What is pathogenicity? | the ability of a pathogen to inflict damage on the host |
What is virulence? | measure of pathogenicity; the ability of a pathogen to cause disease |
What is infection? | situation in which a microbe is established and growing in a host |
What is microbial/ bacterial pathogenesis? | The manner of development of a disease |
What is specific adherence? | surface molecules on a pathogen bind specifically to complementary surface receptors on cells of certain host tissues |
What is non-specific adherence? | bacterial adherence is facilitated by a slime layer or capsule |
Can pathogens form biofilms? | yes |
What are invasins? | virulence factors, bacteria proteins that aid in invasion and promote colonization |
Why do invasins prevent blood from clotting? | protects pathogen from host immune response |
What is bacteremia? | presence of bacteria in the bloodstream |
What is septicemia? | bloodborne systematic infection |
What is toxicity? | the ability to cause disease by means of a toxin that inhibits or kills host cells |
What is a toxin? | a microbial substance able to cause damage to the host |
What is an exotoxin? | proteins released from the pathogen cell as it grows; leaves the site of the initial infection |
What is an endotoxin? | endotoxins are portions of the outer membrane of cell wall released when the bacteria die and the cell wall breaks apart |
What is susceptibility? | lack of resistance to a disease |
What is immunity? | ability to ward off diseases |
What is innate immunity? | defense against any pathogen |
What is adaptive immunity? | immunity or resistance to a specific pathogen |
What is a compromised host? | one or more resistance mechanisms are inactive and so the probability of infection is increased |
What is the first line of defense? | Physical and chemical barriers |
What is the second line of defense? | Inflammatory respinse, antiviral proteins, antibacterial proteins in the blood |
What is the third line of defense? | The adaptive immune system is a pathogen specific, systemic and has memory |
What is humoral/antibody immunity? | b-cells encounter antigens and produce antibodies against them |
What are antigens? | substances that can mobilize the immune system and provoke an immune response |
What are antibodies? | proteins produced by the immune system in response to an antigen . antibodies inactivate antigens and tag them for destruction |
What is cellular or cell-mediated immunity? | t-cells recognize and destroy cells infected with a pathogen |
What are the two types of adaptive immunity? | naturally acquired active immunity and artificially acquired active immunity (vaccinations) |
What are the two things that vaccines do? | spare us the symptoms of diseases and use weakened antigens to stimulate an immune response |
What are autoimmune diseases? | the loss of the immune system's ability to distinguish self from nonself. The body produces antibodies that destroy its own tissues. |
Who is Robert Koch? | A scientist who in 1876 proved that specific microbes cause specific diseases |
What are the Koch postulates? | the suspected pathogen must be present in all cause of the disease and be absent from healthy animals |
What are infectious diseases? | a clinically evident illness resulting from the infection, presence, and growth of a pathogen in a host. Some infections do not cause diseases |
What are communicable diseases? | a disease that is spread from one host to another |
What is a contagious disease? | a disease that is easily spread from from one host to another |
What is a non-communicable disease? | a disease that is not transmitted from one host to another |
What is the morality of a disease? | the incidence of death in a population from the disease |
What is the morbidity of a disease? | The incidence of disease including fatal and nonfatal diseases |
What is the incidence of a disease? | the number of new cases of the disease in a given period of time |
What is the prevalence of a disease? | The total number of new and existing cases in a population in a given time |
What is the outbreak of a disease? | occurs when a number of cases of a disease are reported in a short period of time |
What is an endemic disease? | constantly present in a population usually at low incidences |
What is an epidemic? | occurs in large numbers of people in a population at the same time |
What is the difference between a host-to-host transfer and a common source transfer? | Host-to-host is when people spread the viruses between them and common source is when it is spread through food and water |
What is a pandemic? | widespread - usually world wide |
What is an emerging disease? | an infectious disease that has appeared in a population for the first time or that may have existed previously but is rapidly increasing in incidence or geographical range |
How does the modern world encourage the transfer of viruses? | modern transportation, expanding human settlement, and public health failure? |
What is an infection? | the organisms invades and colonizes the host |
What is the incubation period? | the time between infection and onset of symptoms |
What are symptoms? | changes from normal noticed by the patient that indicate the presence of disease |
What is the acute period? | The disease at the height |
What is the decline period? | When the disease symptoms are subsiding |
What is the convalescent period? | the patient retains strength and returns to the normal mode of transmission |
What is direct host-to-host transmission? | passed from person to person |
What is indirect host-to-host transmission? | transmission is facilitated by living or nonliving facilitator |
What are living agents called? | vectors |
What are nonliving agents called? | fomites |
What are the two ways that arthropods spread pathogens? | mechanical transmission and biological transmission (pathogens replicate in a living agent) |
What is zoonosis? | a disease that primarily infects animals and is occasionally transmitted to humans |
What is a reservoir? | sites (animate or inanimate) in which infectious agents remain viable and from which infection of individuals can occur |
What is a carrier? | a pathogen infected individual showing no signs of clinical disease. Carriers are potential sources of infection and are reservoirs |
What is a HAI | A hospital associated infection |
How are HAI acquired? | as a result of a hospital stay |