Microbiology Study Guide PDF

Questions to Answer: What is microbiology? ○ The study of microorganisms How did the study of microbiology originate ○ Originated with the invention of the microscope What is the comparison between bacteria and our red blood cells? ○ Our red blood cells are ex...

Questions to Answer: What is microbiology? ○ The study of microorganisms How did the study of microbiology originate ○ Originated with the invention of the microscope What is the comparison between bacteria and our red blood cells? ○ Our red blood cells are exceedingly larger than the size of our bacteria. ○ We have singular cells. Bacteria additionally have singular cells but there can be multiple singular cells in one of our cells. What is spontaneous generation/abiogenesis? ○ The belief that life develops from nonliving matter What did proponents and opponents of abiogenesis believe? ○ Proponents supported the idea that life develops from nonliving matter because they saw maggots appear from spoiled food. ○ Opponents opposed this belief. How was the controversy over abiogenesis resolved? ○ The controversy of abiogenesis was resolved through the swan-necked boiled broth experiment conducted by Louis Pasteur. What is bacteria growth characterized by? ○ Bacteria growth is characterized by turbidity, which is the cloudiness of a liquid. What is pasteurization? ○ Heating for a particular combination of temperature and time kills MOST microorganisms and prolongs shelf life.  What is sterilization? ○ The process that kills ALL microorganisms. There are several ways to achieve sterilization such as using the autoclave, UV light, radiation, filtration, chemicals, etc. What is the germ theory of disease? ○ Suspicion that microorganisms cause not only spoilage and decay but also infectious disease What were important discoveries associated with the germ theory of disease? ○ Childbirth deaths linked to dirty hands of physicians ○ Linked maternity infections to contamination of hands ○ Expanded protocols with aerosol disinfection What did Robert Koch investigate? ○ Anthrax What are Koch’s postulates? ○ The causative agent (microbe causing the disease) must be present in every animal with the disease. ○ The microbe can be isolated and grown in pure culture Microbes are bunched together meaning to find the particular causative agent you must isolate them from each other ○ The cultured microorganism must induce the same disease in inoculated animals Inoculate (put the microbe into a healthy individual) to see if an individual gets sick ○ The same microorganisms must then be isolated from the inoculated animal If the healthy individual gets sick from the microbe that was isolated in pure culture then you know that that microorganism was the one causing the disease  How did the vaccination of smallpox come to be? While this was a widespread issue, Edward Jenner noticed there was a group of individuals who appeared to be unaffected. These were the individuals who worked with the cows that experienced pox similar to humans. This shows the importance of epidemiology. ○ Early vaccine development by Edward Jenner from cowpox scabs. He took cowpox scabs and inoculated them into people. Cowpox scabs were not like humans and allowed a cross-reaction immune response to aid against the smallpox people were facing. ○ He proved that immunity against smallpox could be achieved through vaccination. What is a prokaryote, with examples? ○ No membrane-bound organelles, such as a nucleus (pro, before; karyon, nucleus) Examples: Bacteria What is a eukaryote, with examples? ○ With membrane-bound cell organelles, Has a Nucleus Examples: Algae, Fungi, and Protozoans What are viruses? ○ Viruses: particles composed of nucleic acid (DNA or RNA) and a protein coat. They are NOT capable of carrying out any biosynthetic function and depend on their host machinery. What are prions? ○ Prions: (proteinaceous infectious particles) are misfolded proteins with the ability to misfold other proteins. With microorganisms everywhere, why are we not sick all the time? ○ Immune system defense ○ Beneficial microorganisms ○ Pathogen Exposure (not always disease-causing)  How can organisms interact with one another? ○ mutualism: both organisms benefit ○ commensalism: one organism benefits; the other is not affected ○ by parasitism: one organism benefits at the expense of the other. Intent to harm What is microbiome? ○ Microbiome or Normal Flora: Microorganisms that are usually found at given anatomical sites in a healthy human body without causing infection or disease What areas of the human body are sterile? ○ Blood, lymph, cerebrospinal fluid, and internal organs have no microbiome in them. What is a biofilm and where can it develop? ○ Biofilm: a community of microorganisms encased in a matrix. Many surfaces can support biofilm formation including: Tissues Teeth Medical devices What are the health risks associated with biofilms? ○ Growing of bacterial communities ○ Compromising the integrity or function of the device ○ Increased antibiotic resistance What are examples of microorganisms commonly associated with biofilm on medical devices? ○ Staphylococcus Aureus bacteria ○ Candida Albicans yeast What are pathogens? ○ Pathogens: biological entities that cause disease  What factors have lowered the mortality rate caused by infectious agents? ○ Aseptic technique Such as using alcohol to sterilize or using encased tools ○ Antimicrobial drugs Class of medicine Includes antibiotics and antivirals Even if there is a particular antibiotic, pathogens can develop resistance ○ Immunization Vaccination to prevent disease What are examples of food and water-borne diseases, their mode of transmission, and symptoms associated with the disease? ○ E-Coli Transmission: transmits through uncooked meat or other food contaminated by fecal material; swimming in contaminated water Symptoms: severe bloody diarrhea and abdominal cramps ○ Salmonella Transmission: transmits through contaminated poultry, eggs, and meat, fecal-oral route Symptoms: Gastroenteritis, enteric fever, septicemia ○ Hepatitis A Transmission: contaminated food, water contaminated with human feces Symptoms: fever, anorexia, nausea, abdominal discomfort What are examples of airborne diseases, their mode of transmission, and symptoms associated with the disease? ○ Influenza Transmission: Aerosols Symptoms: fever, chills, headache, muscle aches ○ Tuberculosis Transmission: Aerosols Symptoms: Range from asymptomatic to fever, cough, fatigue, lack of appetite, weight loss, pulmonary hemorrhage ○ Common cold Transmission: Aerosols Symptoms: Slight fever, headache, sore throat, coughing, sneezing, nasal discharge  What are examples of microorganisms that can make food? Yogurt Live and active culture Group of bacteria Bread From yeast ○ Alcoholic beverages Wine Beer From yeast What is important to know about prokaryotic and eukaryotic cells and how do they compare to each other? ○ Prokaryotic Cell One chromosome No nucleus None of the developed structures of a cell ○ Eukaryotic cell Multiple One or more nucleus The developed structures of a cell Some Eukaryotic cells can have just one cell - for example: yeast and protozoa.  What are the similarities between prokaryotic and eukaryotic cells? ○ Methods of reproduction by cell division ○ Presence of DNA and RNA for protein synthesis ○ Cellular metabolism is organized into specific metabolic pathways Cellular metabolism = functions Metabolic pathways = process of the function being ○ Key Principle: ALL CELLS HAVE LEARNED TO RESPOND TO THEIR ENVIRONMENT An environment can be the temperature, PH, nutrient levels This is essentially the same as humans being in a harsh environment, they learn to respond to what is happening around them One thing that cells do to react to harsh environments is to help themselves by becoming a spore which is essentially a protective cocoon When a cell becomes a spore it is gaining the ability to withstand that harsh environment they are in until the conditions are good again ○ THINK SLEEPING BEAUTY; sleeping until she found the right conditions Spores can wait for extended periods until they determine that the conditions are right for them What is the basic structure of the phospholipid bilayer? ○ Physophilipid bilayer consists of proteins, lipids, and carbohydrates ○ With the lipids, it is the main component and adds flexibility and proteins are in it for structure. ○ Form dictates function - this is apparent when considering the structure of a cell, its formation, and the function that contributes to the functions that can be fulfilled. What are the two examples of membrane proteins? ○ There are two ways in which proteins give structure to the cell. This is integral (vertically through the cell integrated into the membrane) and peripheral (horizontally through the cell).  What are the functions of plasma proteins? ○ Structural Support ○ Transport of molecules across the membrane THINK OF INTEGRAL MEMBRANE WHICH GOES VERTICALLY ○ Receptors for hormones and other regulatory substances Signals are being sent and received to know what to do There needs to be receptors to get the message to relay the information to the molecules in the cell to carry out a function ○ Surface antigens (Immunological Recognition) This is the recognition of bacteria from cells to attack the bacteria to sustain itself. What is glycocalyx and what is its function? ○ Some cells have glycocalyx or capsules. These capsules are made out of sugar and surround bacteria or animal cells. ○ Bacteria use their glycocalyx capsule to communicate and additionally help the cells get sticky. THINK MELTED JELLY BEANS. The glycocalyx capsule allows for the bacteria to be sticky. The bacteria wants to be sticky to stay in the body to cause infection. Our body has natural defenses to try and get rid of bacteria such as sneezing, coughing, urinating, and defecating. However, when sticky it stays and becomes difficult to get rid of and then can cause an infection. Bacteria want to form a biofilm layer to protect themselves further than just having the glycocalyx capsule. Glycocalyx capsule is one particular method that bacteria use to get sticky to stay in the body to cause infection but there are other ways. ○ Glycocalyx capsule is essentially a literal and figurative sugar coating to trick the immune system into evading detection. What are the virulence factors of bacteria? ○ Many virulence factors Having a capsule Difficulty in detection Sticky Slippery (sly)  What are some important things to know about Klebsiella pneumoniae? ○ This is a part of our microbiome (meaning it is fine in the right place and right proportion) ○ This is a bacteria that has a Glycocalyx capsule. ○ It is located in the intestines, but when misplaced can give you deadly pneumonia. ○ Easily contaminated within healthcare facilities ○ Found typically in an individual’s stool ○ Can easily create biofilm and resistant to antibiotics Do animals have cell walls? ○ No cell wall because it would hinder activities & functions What is a bacteria cell wall made of? ○ Bacteria cell wall is made of peptidoglycan What is peptidoglycan made of and what does the structure look like? ○ Peptidoglycan is a cross-bridge structure of sugars and proteins A thick peptidoglycan layer is associated with positive or negative gram staining? ○ Positive Gram Staining, meaning it is easier to see with a microscope A thin peptidoglycan layer is associated with positive or negative gram staining? ○ Negative Gram Staining, meaning it is harder to see with a microscope Why are the differences in the cell wall composition important in selecting the appropriate antimicrobial drug? ○ Differences help healthcare workers identify microbes so they can properly combat them. This is done so by the differences in the cell wall that provide clues of what medicine should be used to combat it.  What is pathogen load and why is it important? ○ Pathogen load refers to the quantity or concentration of pathogenic microorganisms (such as bacteria, viruses, fungi, or parasites) present in a host organism, environment, or specific system. The concept is important in understanding disease dynamics, infection severity, transmission, and host immune responses. For a thick peptidoglycan layer is the periplasmic space large or small? ○ Periplasmic space is small because it is less complex. The small periplasmic space makes it easier for antibiotics to penetrate to work faster. For a thin peptidoglycan layer is the periplasmic space large or small? ○ Periplasmic space is large because it is more complex. This makes it harder to penetrate, making it difficult for antibiotics to enter and this contributes to antibiotic resistance.  What are lipopolysaccharides and which gram staining is it associated with? ○ What is it? Lipopolysaccharide (LPS) is a large, complex molecule found in the outer membrane of Gram-negative bacteria. It plays a key role in the structure and function of the bacterial cell wall and interactions with the host immune system. LPS is also known as endotoxin because it can trigger strong immune responses in animals, including humans. ○ Where is it located? Outer Membrane of Gram-negative Bacteria: LPS is a major component of the outer leaflet of the outer membrane in Gram-negative bacteria, where it contributes to the barrier function of the membrane and protects the bacteria from harmful substances. ○ What is its function? Structural Integrity: LPS provides structural stability to the outer membrane of Gram-negative bacteria, helping to protect the cell from physical damage and harmful substances such as antibiotics and detergents. Barrier Function: It acts as a protective barrier, limiting the entry of toxic substances, including bile salts and certain antibiotics, into the bacterial cell. What is more complex gram-negative or gram-positive? ○ Gram-negative bacterial cells are more complex due to the thin peptidoglycan and the LPS. Thin peptidoglycan has a larger periplasmic space making penetration of antibiotics harder additionally, LPS acts as a barrier to protect against antibiotics. What are surface appendages of bacteria used for? ○ Surface appendages of bacteria are primarily used for movement to react to their environment.  What is bacterial flagella and what is important to know about it? ○ What is it Flagella (singular: flagellum) are long, whip-like appendages that protrude from the surface of many prokaryotic and eukaryotic cells. They are primarily used for locomotion, allowing cells to move through liquid environments. Flagella are especially important in bacteria and certain single-celled eukaryotes, such as protists and sperm cells. ○ Where is it They are anchored in the cell membrane and cell wall through a complex of rings and a hook that allows them to rotate. Can be arranged in various ways ○ What is its function The primary function of flagella is movement. Cells use flagella to swim toward favorable environments (such as nutrient sources) or away from harmful stimuli (such as toxins) in a process called chemotaxis. What are taxis and what are the two patterns associated? ○ Patterns of mobility Runs (swims) A run (or swim) is a smooth, straight movement in which the bacterium moves in a single direction. Tumbles A tumble is an abrupt, random reorientation of the bacterium. This occurs when the flagella rotates clockwise (CW), causing the bundle of flagella to break apart and spin independently. ○ This run-tumble behavior is a fundamental and efficient survival strategy for bacteria to find food, avoid danger, and optimize their living conditions in dynamic environments.  What is pili, where is it located, and what is its function? ○ What is it Hair-like appendages are found on the surface of many bacterial cells. They are composed of a protein called pilin and are primarily found in Gram-negative bacteria. Contributes to the bacteria’s interaction with the environment ○ Where is it located On the outer surface of the bacteria ○ What is its function Attachment: Pili play a crucial role in allowing bacteria to adhere to surfaces, including host tissues, which is essential for colonization and infection. Conjugation: Specialized pili, called sex pili, are involved in a process called bacterial conjugation, where genetic material (usually plasmids) is transferred from one bacterium to another. This can spread antibiotic resistance or other traits among bacteria. Motility: Some types of pili, such as type IV pili, help bacteria move by a process called twitching motility, allowing them to crawl along surfaces. What is cilia, where is it located, and what is its function? ○ What is it Cilia are microscopic, hair-like structures found on the surface of eukaryotic cells. They are composed of microtubules arranged in a specific pattern and are covered by the cell’s plasma membrane. Cilia are present in both single-celled organisms (such as some protists) and multicellular organisms (such as humans). ○ Where is it located Cilia are found on the surface of many types of eukaryotic cells. In humans, they are particularly common in the respiratory tract, reproductive system, and other specialized tissues. ○ What is its function? In multicellular organisms, cilia move fluids or mucus across the cell surface. For example, in the human respiratory tract, cilia help clear mucus and trapped particles out of the lungs, aiding in protection against infections.  What is the positive use of biofilms? ○ Bioremediation Petroleum-digesting bacteria Using microbes to clean up oil spills that kill bacteria What is the cytoplasm? ○ What is it The cytoplasm is a gel-like substance inside the cell, composed primarily of water, salts, and proteins. It encompasses everything within the cell membrane, excluding the nucleus in eukaryotic cells. The cytoplasm contains all the organelles and cellular components necessary for the cell's function. ○ Where is it the cytoplasm is located inside the cell membrane, filling the entire interior of the cell. In eukaryotic cells, it surrounds the cell organelles and the nucleus. ○ What is its function Support and Shape: The cytoplasm gives the cell its shape and helps keep organelles in place. The cytoskeleton within the cytoplasm is a network of fibers that provides structural support and aids in movement. Transport: It allows the movement of materials, such as nutrients, waste, and organelles, within the cell. Site of Protein Synthesis and Metabolism  What are lysosomes and why are they important? ○ What is it Lysosomes are membrane-bound organelles found in eukaryotic cells, particularly in animal cells. They contain a variety of digestive enzymes that break down different types of biological molecules such as proteins, lipids, carbohydrates, and nucleic acids. ○ Where is it Lysosomes are located in the cytoplasm of eukaryotic cells. ○ What is its function Lysosomes are specialized organelles in eukaryotic cells responsible for breaking down waste, recycling cellular components, and defending against pathogens. They are essential for maintaining cellular health and proper function. What are the four biosafety levels of a laboratory? ○ Biosafety level one (considered the safest) ○ Biosafety level two (next level up in danger within the lab) ○ Biosafety level three ( third level up in danger within the lab) ○ Biosafety level four (most dangerous)  What are hospital associated infections and why are they important? ○ These are infections that patients acquire during their stay in a healthcare setting. These infections typically occur 48 hours or more after admission and are unrelated to the patient's original reason for hospitalization. ○ HAIs can lead to severe complications or death, especially in patients with compromised immune systems, the elderly, or those undergoing invasive procedures. ○ Infections can prolong hospital stays, delay recovery, and increase morbidity. For example, surgical site infections can extend recovery time, increase pain, and require further interventions. ○ Many HAIs are caused by antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). These infections are harder to treat because they do not respond to standard antibiotic therapies, leading to higher morbidity and mortality rates. What does OSHA stand for and what do they do? ○ OSHA stands for the Occupational Safety and Health Administration. It is a U.S. federal agency under the Department of Labor that was created to ensure safe and healthy working conditions for employees by enforcing standards and providing training, outreach, education, and assistance.  What does HHS stand for and what do they do? ○ HHS stands for the U.S. Department of Health and Human Services. It is a federal agency responsible for protecting the health of all Americans and providing essential human services, especially for those least able to help themselves. What are examples of organisms for biosafety level 1? ○ Ecoli ○ Lactobacillus spp. ○ Chicken Pox What are examples of organisms for biosafety level 2? ○ Salmonella ○ Staphylococcus aureus ○ Streptococcus pyrogens ○ Influenza ○ All forms of hepatitis What are examples of organisms for biosafety level 3? ○ Anthrax ○ Tuberculosis What are examples of organisms for biosafety level 4? ○ Smallpox ○ Ebola  What are MSDSs within laboratories? ○ MSDSs (now referred to as SDSs or Safety Data Sheets) are detailed documents that provide critical information about the properties, hazards, handling, storage, and disposal of chemicals used in laboratories and workplaces. What are examples of safety issues within healthcare facilities? ○ Bloodborne pathogens ○ Biological hazards ○ Potential chemical and drug exposure ○ Waste products