Microbiology Exam II

Explain the difference between -static and -cidal or -cide physical and chemical methods of microbial control.

-cide means to kill -static means to inhibit growth

Describe how these chemical preservatives work, their common uses, and limitations. a. sorbic acid b. propionic acid c. benzoic acid

All change the pH and Inhibit microbial growth and prevent spoilage a) Sorbic acid inhibit cellular enzymes b) Propionic acid inhibit cellular enzymes and decrease intracellular pH c) Benzoic acid decreases intracellular pH, interferes with oxidative phosphorylation, and prevents uptake of certain amino acids

Describe the role these play in host immune system evasion: a. capsules b. proteases c. M protein d. mycolic acid e. coagulase f. kinases g. antigenic variation

Avoiding immune system response a) The composition of the capsule prevents immune cells from being able to adhere (stick) and then phagocytose (ingestion of bacteria) the cell and grow b) Proteases combat antibody-mediated killing and clearance by attacking and digesting the antibody molecules c) Produced by Streptococci and stops phagocytosis by blocking the binding of the complement molecules that assist phagocytes in ingesting bacterial pathogens d)Produced by Mycobacterium tuberculosis and The protective mycolic acid coat enables the bacterium to resist some of the killing mechanisms within the phagolysosome-- when phagosome and lysosome fuse e) Produced by Staphylococcus aureus ---Fibrinogen-to-fibrin (helps form a clot) cascade is triggered in the absence of blood vessel damage Protects the bacterium from phagocytic blood cells f) Produced by Staphylococcus aureus and Streptococcus pyogenes Dissolve fibrin clots g) Alteration of surface proteins so that a pathogen is no longer recognized by the host's immune system

Define bacterial toxins and list the two types.

Biological poisons that assist in their ability to invade and cause damage to tissues two types Exotoxin Endotoxin

Compare and contrast endotoxins and exotoxins.

Endotoxins- Only produced by gram negative bacteria Lipid A released from Gram negative bacterial cell wall (heat stable not broken down by heat) Exotoxins- produced by both Gram positive and Gram negative pathogens more usually made of protein molecules more specific in effect and may require very low amounts to be toxin break down in heat

Define Drug Resistance and list the factors that contribute to it.

Several important factors can accelerate the evolution of drug resistance. These include the overuse and misuse of antimicrobials, inappropriate use of antimicrobials, subtherapeutic dosing, and patient noncompliance with the recommended course of treatment.

Explain the purpose of and list the body's portals of entry.

eye nose mouth ear anus urethra placenta- portal to infect the fetus vagina Parenteral route: Pathogens enter through a breach in the protective barriers of the skin and mucous membranes examples: insect bite broken skin needle

Explain how these exotoxins increase invasion of and damage to host tissues. a. cholera toxin b. botulinum neurotoxin c) Diphtheria Toxin d) Tetanus toxin

a) (exotoxin) intracellular targeting toxin that is able to target the digestive track when Activation of adenylate cyclase in intestinal cells, causing increased levels of cyclic adenosine monophosphate and secretion of fluids and electrolytes out of the cell, causing diarrhea dehydrates you and doesn't allow to absorb fluids causing diarrhea--- dehydration--- then death b) stops the release of the neurotransmitter acetylcholine from neurons, resulting in flaccid paralysis, stops muscle contraction difficulty seeing, hard to swallow, c) Diphtheria toxin- stopping of protein synthesis, causing cellular death d) Stops the release of inhibitory neurotransmitter in the central nervous system, causing spastic paralysis stops uncontrollable muscle contraction

Chapter 15 Define and differentiate between: a. infection and disease b. signs and symptoms

a) ---Infection: the successful colonization of a host by a microorganism ---Disease: any condition in which the normal structure or functions of the body are damaged or impaired b) ---Signs: objective and measurable, and can be directly observed by a clinician ---Symptoms: are subjective they are felt or experienced by the patient, but they cannot be clinically confirmed or objectively measured

For these physical protocols, indicate methods used, whether it sterilizes, is sporicidal, and common uses: a. sonication b. air HEPA filtration c. liquid membrane filtration

a) -High frequency ultrasound waves -Disrupts cell structures -Cleans surgical instruments, lenses, and other objects -Does not sterilize b/c) Physically separates microbes from sample - Can sterilize depending on the sample

Define: a. syndrome b. asymptomatic or subclinical c. zoonotic disease

a) A specific group of signs and symptoms characteristic of a particular disease b) meaning they do not present any noticeable signs or symptoms c) not transmitted between humans directly but can be transmitted from animals to humans

Explain the purpose of the body's portals of exit and list their secretions and excretions.

eye- tears nose- secretions mouth- saliva ear- ear wax anus- poop urethra- urine, semen placenta- transmission to infect the fetus vagina- blood, secretions skin- flakes broken skin- blood needle- blood mammary glands (boobs)- milk, secretions

Chapter 13: Define fomite

inanimate objects that can transmit disease

Define the term selective toxicity and why there are many antibacterial drugs.

meaning that it selectively kills or inhibits the growth of microbial targets while causing minimal or no harm to the host. Most antimicrobial drugs currently in clinical use are antibacterial because the prokaryotic cell provides a greater variety of unique targets for selective toxicity

Define logarithmic growth/exponential growth. Explain how the population count is calculated.

the cells are actively dividing by binary fission and their number increases exponentially.

Describe how virulence is related to pathogenicity.

Pathogenicity: ability of a microbial agent to cause disease Virulence: degree to which an organism is pathogenic

Explain how Biofilms can positively and negatively impact human health.

◦ Catheters ◦ Joint replacements ◦ Dental plaque ◦ Contact lenses

Explain the four steps of Koch's postulates

---(1) The suspected pathogen must be found in every case of disease and not be found in healthy individuals. ---(2) The suspected pathogen can be isolated and grown in pure culture. ---(3) A healthy test subject infected with the suspected pathogen must develop the same signs and symptoms of disease as seen in postulate 1 . ---(4) The pathogen must be re -isolated from the new host and must be identical to the pathogen from postulate 2 .

Discuss the risk associated with using broad-spectrum antimicrobials (include term superinfection.)

--Can lead to a superinfection in some individuals --Secondary infection in those already having an infection --Pseudomembranous colitis caused by Clostridium difficile leads to diarrhea

Name and briefly explain the five periods of disease

1) Incubation period: (Asymptomatic) Been exposed, microbes attached to person and infecting that person, but hasn't caused enough damage to make that person show symptoms depends on immune systems, overall health, pathogen itself 2) Prodromal period: Pathogens increasing in amounts and starting to show negative effects on body where you can notice; First sign of symptoms begin to show 3) Period of Illness: When you are sick the most, feeling the worst, have the most pathogens 4) Period of Decline: Start to feel a little better, pathogen amounts start to decrease 5) Period of Convalescence: Clear all pathogens from the body and all symptoms disappear

Define and explain the importance of using a chemostat system.

A chemostat is used to maintain a continuous culture in which nutrients are supplied at a steady rate. A controlled amount of air is mixed in for aerobic processes. Bacterial suspension is removed at the same rate as nutrients flow in to maintain an optimal growth environment.

List the 4 levels of biosafety and provide examples of how microbes are to be handled at each level

BSL-1: Microbes are not known to cause disease in healthy hosts and pose minimal risk to workers and the environment. Personal protective gear not really needed, but used for extra precautions (E. coli) BSL-2: Microbes are typically indigenous and are associated with diseases of varying severity. They pose moderate risk to workers and the environment. Definitely need personal protective gear. (S. aureus) BSL-3: Microbes are indigenous or exotic and cause serious or potentially lethal diseases through respiratory transmission. (TB) BSL-4: Microbes are dangerous and exotic, posing a high risk of aerosol-transmitted infections, which are frequently fatal without treatment or vaccines. Few labs are at this level. (Ebola)

Discuss how septicemia can lead to shock and death

Bacteria are both present and multiplying in the blood, this condition is called septicemia Patients with septicemia are described as septic Can lead to shock , a life-threatening decrease in blood pressure (systolic pressure < 90mm Hg) that prevents cells and organs from receiving enough oxygen and nutrients Can lead to death

Describe the relationship between salinity, osmotic pressure, and food preservation.

Decreasing the water content of foods by drying, as in jerky, or through freeze-drying or by increasing osmotic pressure, as in brine and jams, are common methods of preventing spoilage.

Differentiate between moist and dry heat sterilization. Explain which one is more efficient and why

Dry Heat Sterilization -Burning or incineration -Dry oven 170˚C for at least 2 hours Moist Heat Sterilization -Autoclave -Brings temperature of water to 121˚C to boil using increased pressure -Can kill all vegetative cells, endoscopes, and destroy all viruses -Boiling water at 100˚C does not kill endoscopes

Distinguish between median infectious dose (ID50) and median lethal dose (LD50).

ID50: the number of pathogen cells or virions required to cause active infection in 50% of inoculated animals LD50: the number of pathogenic cells, virions, or amount of toxin required to kill 50% of infected animals

Explain how the Microbial Death Curve and the Decimal Reduction Time are used to evaluate microbial control protocols.

Microbial Death Curve: Tracks decline (death) of population and Not all cells die at the same time Decimal Reduction Time: -Time to reduce population ten-fold on a log scale (90% on an arithmetic scale) -Depends on amount of starting population -Depends on temperature or concentration of chemicals -Depends on organic matter present

Describe the Bacterial Growth Curve in a Closed (Batch) Culture. Name the four phases and state what occurs in each one.

Microorganisms grown in closed culture (also known as a batch culture), in which no nutrients are added and most waste is not removed, follow a reproducible growth pattern referred to as the growth curve. An example of a batch culture in nature is a pond in which a small number of cells grow in a closed environment 1) Lag Phase: The initial phase of the growth curve is called the lag phase, during which cells are gearing up for the next phase of growth. The number of cells does not change during the lag phase; however, cells grow larger and are metabolically active, synthesizing proteins needed to grow within the medium. If any cells were damaged or shocked during the transfer to the new medium, repair takes place during the lag phase. 2) Log Phase: the cells are actively dividing by binary fission and their number increases exponentially; show constant growth rate and uniform metabolic activity; the relationship between time and number of cells is not linear but exponential. The stage where bacteria are the most susceptible to the action of disinfectants and common antibiotics that affect protein, DNA, and cell-wall synthesis. 3) Stationary Phase: The total number of live cells reaches a plateau referred to as the stationary phase. In this phase, the number of new cells created by cell division is now equivalent to the number of cells dying; thus, the total population of living cells is relatively stagnant. As growth slows, so too does the synthesis of peptidoglycans, proteins, and nucleic-acids; thus, stationary cultures are less susceptible to antibiotics that disrupt these processes. 4) Death/Decline Phase: Soon, the number of dying cells exceeds the number of dividing cells, leading to an exponential decrease in the number of cells called the Death Phase. Many cells lyse and release nutrients into the medium, allowing surviving cells to maintain viability and form endospores.

Discuss the role of agar in culture media.

Nutrient agar is popular because it can grow a variety of types of bacteria and fungi, and contains many nutrients needed for the bacterial growth.

Define endotoxin and discuss our body's response to it.

Only produced by gram negative bacteria Lipid A released from Gram negative bacterial cell wall High concentrations of endotoxin in the blood can cause an excessive inflammatory response, leading to a severe drop in blood pressure, multi-organ failure, and death

Describe how temperature affects proteins and lipids and what is meant by the minimum, maximum, and optimum growth temperatures

The lowest temperature at which the organism can survive and replicate is its minimum growth temperature. The highest temperature at which growth can occur is its maximum growth temperature The growth rates are the highest at the optimum growth temperature for the organism.

Define thermal death point and thermal death time and explain the significance of these numbers.

Thermal Death Point: Lowest temperature to kill all microbes within a 10 minute period Thermal Death Time: Amount of time it takes to kill all microbes at a particular temperature

Describe the dangers of: multiple drug resistant microbes (MDRs)

They are a problem. There are different bacteria out there that have resistance to one or more antimicrobials antibiotics which makes it harder to treat these diseases

Briefly discuss these stages of pathogenesis: a. exposure b. adhesion (include terms adhesions, biofilms) c. invasion (include role of virulence factors) d. infection

a) An encounter with a potential pathogen portal of entry b) The pathogen adheres (sticks) at the portal of entry Adhesins are found on the surface of certain pathogens and bind to specific receptors (glycoproteins) on host cells Fimbriae Flagella Glycocalyx c) Invasion involves the dissemination of a pathogen throughout local tissues or the body d) Local infection: confined to a small area of the body, typically near the portal of entry Staphylococcus aureus Focal infection: a localized pathogen, or the toxins it produces, can spread to a secondary location Streptococcal species Systemic infection: an infection becomes disseminated throughout the body Chickenpox Primary infection the initial infection caused by one pathogen Influenza Secondary infection: infection that occurs after a primary infection due to a compromised immune system Haemophilus influenzae

Briefly explain the significance in testing the effectiveness of antimicrobials of these: a. Kirby-Bauer Disk Diffusion Susceptibility test (include term zone of inhibition) b. Minimum Inhibitory Concentration (MIC)

a) Bacteria swabbed on the plate or disk, use different antibiotics or synthetic antimicrobials on that bacteria, if there is a clear zone, zone of inhibition, around the drug/antibiotic point then measure the diameter to see how sensitive or effective it is against the bacteria and if not then the microbe (bacteria) is resistant to drug/antibiotic b) Have a series of broth tubes with the same amount and kind of media in all the tubes. Then add the same amount of the same kind of bacteria to each test tube. The only difference is the amount of the chemotherapeutic agent. 2, 4, 8, 16, & 32 µg/mL. If it is turbid (cloudy) then the microbes are growing and that the levels do not prevent growth. If it doesnt look cloudy then have to verify with spectrophotometer. Then if there is truly no growth then the minimal inhibitory concentration is 8 or the lowest concentration that doesn't have growth.

Define: a. Bacteriostatic b. Bactericidal

a) Bacteriostatic: bacteria can't grow when chemical present but can grow if it is removed b) Bactericidal: bacteria killed

Chapter 9 Define: a. binary fission b. generation time c. culture density

a) Cell replication process in prokaryotes b)the time it takes the newly formed cell for the process of dividing and growing again More than just the time to physically divide but Varies depending on species and growth conditions Calculating the number of cell: Nn = N0 2n -Nn is the number of cells at any generation n, N0 is the initial number of cells, and n is the number of generations. c)The culture density is defined as the number of cells per unit volume. In a closed environment, the culture density is also a measure of the number of cells in the population.

Define these physical and/or chemical microbial control protocols: a. sterilization b. sterilant c. aseptic technique

a) Complete removal of all microbes including vegetative cells, endospores, and viruses b) Chemicals that can sterilize if used properly c) Techniques to maintain sterility or prevent contamination

Indicate the role these exoenzymes play in host cell invasion: a. hyaluronidase b. proteases

a) Degrades hyaluronic acid that cements cells together to promote spreading through tissues b) Degrades collagen in connective tissue to promote spread

Describe these methods to estimate Bacterial Count in a culture. State whether the method is Direct or Indirect. a. microscopic cell count (Petroff-Hausser Chamber) b. Coulter counter c. serial dilution & viable plate count d. membrane filtration e. most probable number (MPN) f. turbidity (Spectrophotometer)

a) Direct. Using a calibrated slide, a Petroff-Hausser Chamber, and light microscope to directly count cells. Known volume added to counter and cells are tallied in a given area of squares. ◦ Calculations help determine cell number, Error rate high but quick and easy to use b) Direct. Cells move through system and electronic sensor changes used to count cells ◦ Fast and accurate as long as concentration of cells not too high c) Direct. Colony forming unit: Living cell that can divide to give rise to a visible colony ◦ Sample must be diluted first ◦ Keep track of dilution, volume plated, and number of colonies ◦ Amount can be put into equate to determine living number of cells ◦ N = C / DV (N = number of viable cells, C = number of colonies, D = dilution factor, and V = volume plated) ◦ Not accurate if over 300 colonies on plate d) not on slides e) Direct. Good for dilute samples of bacteria ◦ Often used for coliform water testing the MPN method evaluates detectable growth by observing changes in turbidity or color due to metabolic activity. f) Indirect. measure the turbidity (cloudiness) of a sample of bacteria in a liquid suspension ◦ Use spectrophotometer ◦ Light scattered the more cells in a sample ◦ Electrode detects and provides transmission or optical density data

1. Discuss the oxygen requirements of these groups of organisms: a. obligate aerobes b. obligate anaerobes c. facultative anaerobes d. aerotolerant anaerobes e. microaerophiles

a) Does use oxygen to grow b) Oxygen kills the microbes c) Can grow with or without oxygen but grows better with oxygen d) Don't use oxygen but can tolerate it e) Grows best with a little less oxygen, doesn't grow with oxygen

Define these radiation protocols and indicate the types, strength, how they kill, whether they are sporicidal, common uses: a. ionizing radiation b. nonionizing radiation

a) Examples: X-rays, Gamma rays, High energy electron beams How it works: Damages DNA Ionizes water to make Reactive Oxygen Species Uses: Sterilize materials that can't be autoclaved Sterilize tissues and drugs Food preservation (lower microbial counts) b) Examples Microwaves (heat) UV light How it works: Microwaves generate heat, UV light damages DNA but not endospores Uses: -Water purification but not sterilize just kills some microbes -Germicidal lamps (when not using areas turn on these lights to kill microbes) -Biological safety cabinets

For these pressure protocols, indicate methods used, whether it is sporicidal, common uses, and limitations: a. pascalization b. hyperbaric oxygen therapy

a) Exposure to high pressure kills many microbes, lower microbial growth, not to sterilize, used in food industry (pet food) b) Patient breathes pure oxygen at higher pressure -Increases oxygen content in blood -Increases immune activity -Increases Reactive Oxygen Species which can damage strict anaerobes causing infection

For these cold protocols, indicate the temperature used, how it works, whether it is sporicidal, common uses, and limitations: a. refrigeration b. freezing

a) Good a slowing down reactions and microbial growth, preventing microbes from growing, preserving for the long return b) Good a slowing down reactions and microbial growth, preventing microbes from growing, preserving for the long return, might kill some microbes

Indicate how these contribute to Influenza viral virulence: a. adhesions b. antigenic drift c. antigenic shift

a) Hemagglutinin which allows virus to attach to host attachment site-- intestinal cells b) a mutation that takes place in the genome of the virus,,, antigenic drift leads to small changes in the virus Influenza is an RNA and segmented virus c) can lead to pandemic situations two versions of the virus infects the same host which can come out of that host a totally different virus reassortment of the genome and not a just a simple mutation giving a very different version it is a antigenic shift

Define and differentiate between these diseases: a. infectious and noninfectious b. communicable, contagious, and noncommunicable c. iatrogenic and nosocomial

a) Infectious disease: any disease caused by the direct effect of a pathogen Noninfectious diseases: not caused by pathogens b) Communicable: capable of being spread from person to person through either direct or indirect mechanisms Contagious diseases: easily spread from person to person Noncommunicable disease: not spread from one person to another c) Iatrogenic diseases: contracted as the result of a medical procedure are known as iatrogenic diseases Nosocomial diseases: acquired in hospital / healthcare settings

Differentiate between these types of infection: a. local b. focal c. systemic d. primary/secondary

a) Local infection: confined to a small area of the body, typically near the portal of entry Staphylococcus aureus b) Focal infection: a localized pathogen, or the toxins it produces, can spread to a secondary location Streptococcal species c) Systemic infection: an infection becomes disseminated throughout the body Chickenpox d) Primary infection the initial infection caused by one pathogen Influenza Secondary infection: infection that occurs after a primary infection due to a compromised immune system Haemophilus influenzae

Explain and differentiate between these items and the required microbial control protocols: a. critical items b. noncritical items c. semicritical items

a) Medical equipment that must be sterile b) Need to be clean but not highly disinfected c) Highly disinfected but not necessarily needing to be sterile

Explain the temperature requirements of these groups of organisms: a. mesophile b. psychotroph c. psychrophiles d. thermophiles e. hyperthermophiles

a) Mesophiles are adapted to moderate temperatures b) Psychotrophs prefer cold environments (cold) c) Psychrophiles are cold loving (very cold) d) Thermophiles are heat loving (hot) e) Hyperthermophiles survive very hot temperatures

Explain the special growth requirements of these groups of organisms: a. halophiles b. halotolerant organisms

a) Microorganisms called halophiles ("salt loving") actually require high salt concentrations for growth. b) do not need high concentrations of salt for growth, they will survive and divide in the presence of high salt.

For these heat protocols, indicate time and temperature used, whether it is sporocidal, common uses, and limitations. a. boiling water b. incineration c. oven d. autoclave e. high-temperature short-time pasteurization (HTST) f. ultra-high-temperature pasteurization (UHT)

a) Moist heat sterilization b) Dry heat sterilization c) Dry heat sterilization Dry oven 170˚C for at least 2 hours d) Moist heat sterilization -Brings temperature of water to 121˚C to boil using increased pressure -Can kill all vegetative cells, endoscopes, and destroy all viruses -Boiling water at 100˚C does not kill endoscopes e) used to increase shelf life and kill pathogenic microbes. Uses high temperatures for a short time (milk 72˚C for 15 sec) f) used to increase shelf life and kill pathogenic microbes. Uses higher temperatures for a shorter time and kills off more organisms. (Milk 138˚C for 2 sec)

Explain the pH requirements of these groups of organisms: a. Neutrophils b. acidophiles c. alkalinophiles

a) Most bacteria are neutrophiles, meaning they grow optimally at a pH within one or two pH units of the neutral pH of 7 b) Microorganisms that grow optimally at pH less than 5.55 are called acidophiles. c) alkaliphiles, microorganisms that grow best at pH between 8.0 and 10.5.

Define these types of antimicrobial drugs: a. narrow-spectrum b. broad-spectrum

a) Narrow spectrum: only targets a specific group of microbes b) Broad spectrum: targets a variety of microbe types --Can lead to a superinfection in some individuals --Secondary infection in those already having an infection --Pseudomembranous colitis caused by Clostridium difficile

Explain how these scientists played a role in the development of antimicrobial drugs: a. Paul Ehrlich b. Gerhard Domagk c. Alexander Fleming d. Dorothy Hodgkin

a) Paul Ehrlich's compound 606 -arsenic-containing compounds -for treatment of syphilis b) Gerhard Domagk and others discovered prontosil -Breaks down into sulfanilamide in the body -Used to treat Streptococcal and Staphylococcal infections -Sulfanilamide is a synthetic antimicrobial (not naturally made) c) Alexander Fleming discovers penicillin -Discovered by accident -Used to treat Streptococci, Staphylococci, Meningococci, and diphtheria -Penicillin is a natural antibiotic (naturally produced) d) Dorothy Hodgkin determined chemical structure of penicillin -Allowed for modification of penicillin to make semisynthetic antimicrobials

For each chemical group listed, indicate the mode of action of microbial control and whether it is sporicidal. For each example, list its common uses and limitations. a. Phenolics: bisphenol hexachlorophene and triclosan b. Heavy Metals: mercury, silver, copper, and zinc c. Halogens: iodine, chlorine, and fluorine d. Alcohols: ethyl alcohol and isopropyl alcohol

a) Phenolics -Lister first use clinical (carbolic acid) -Work by denaturing proteins and disrupting membranes Common Examples: Lysol, Triclosan, pHisoHex b) Heavy metals Used early in history: Mercury to treat syphilis, Silver nitrate droplets to protect newborn eyes, Copper prevents algae growth, Nickel and Zinc also have antimicrobial properties -Work by binding to proteins and denaturing enzymes, prevent microbial growth -Common examples: Mostly clinical settings (mercuric chloride disinfectant), Silver in bandages, Zinc oxide in diaper rash cream, and dandruff shampoo c) Halogens: iodine, chlorine, and fluorine How they work: -Iodine and chlorine act as oxidizing agents and Damage organic molecules -Fluorine incorporated into tooth enamel to Strengthen it and also can accumulate in bacteria Disrupting their metabolism -Common examples: Betadine, Bleach (chlorine), Various toothpastes, mouthwash, and municipal Water (fluorine) d) Alcohols: 70% isopropyl and 70% ethanol -Also form tinctures when combined with other antimicrobials (iodine) How they work: -Denature proteins -Disrupt cell membranes -Lead to cell lysis Common Examples: Alcohol based hand sanitizer, Alcohol pads

Define and describe these types of pathogens: a. primary b. opportunistic

a) Primary Pathogen: can cause disease in a host regardless of the host's resident microbiota or immune system ---Examples: food borne pathogens This means that it doesn't matter if you are at your best health or not it will cause disease ---Primary pathogen- perfectly healthy to start and a new microbe is introduced to your body and if it infects you then it causes disease b)Opportunistic Pathogens: can only cause disease in situations that compromise the host's defenses, such as the body's protective barriers, immune system, or normal microbiota ----This means that you are not at your best health and there is an opportunity for the pathogen to cause disease ----Usually caused by a microbe that's your normal flora or a microbe that starts as a primary pathogen and then takes an opportunity to go elsewhere in the body to get other diseases

Define drug resistance mechanisms of action and describe these examples: a. Drug modification or inactivation b. Cellular uptake prevention or efflux c. Target modification d. Target overproduction e. Enzymatic bypass f. Target mimicry

a) Resistance genes may code for enzymes that chemically modify an antimicrobial, thereby inactivating it, or destroy an antimicrobial through hydrolysis. b) Microbes may develop resistance mechanisms that involve inhibiting the accumulation of an antimicrobial drug, which then prevents the drug from reaching its cellular target. This strategy is common among gram-negative pathogens and can involve changes in outer membrane lipid composition, porin channel selectivity, and/or porin channel concentrations. c) Because antimicrobial drugs have very specific targets, structural changes to those targets can prevent drug binding, rendering the drug ineffective. Through spontaneous mutations in the genes encoding antibacterial drug targets, bacteria have an evolutionary advantage that allows them to develop resistance to drugs. This mechanism of resistance development is quite common. d/e) When an antimicrobial drug functions as an antimetabolite, targeting a specific enzyme to inhibit its activity, there are additional ways that microbial resistance may occur. First, the microbe may overproduce the target enzyme such that there is a sufficient amount of antimicrobial-free enzyme to carry out the proper enzymatic reaction. Second, the bacterial cell may develop a bypass that circumvents the need for the functional target enzyme. f) ​A recently discovered mechanism of resistance called target mimicry involves the production of proteins that bind and sequester drugs, preventing the drugs from binding to their target.

For these antimicrobial drugs, describe the mode of action and the microbes they are used against: (Antimicrobial Drugs) a. vancomycin b) polymixins c) Antimetabolites: sulfonamides d) Izoniazid

a) Somehow interfering in the peptidoglycan cell wall --a cell wall targeting antimicrobial, but does have more potential side effects issues (MRSA) --on it for extended periods time then might lead to kidney damage b) a plasma membrane targeting antimicrobial - used as ointments--- putting it on cuts and scrapes doesn't cause harm to human host since on the outer skin c) Metabolic pathways this blocks Folic acid synthesis humans don't produce folic acid but get it from diet d) Metabolic pathways this blocks Mycolic acid synthesis from producing enough of that waxy coating so that it can penetrate to harm the microbe

Describe the types of media listed below and when each is used: a. General purpose media b. chemically defined c. complex d. enriched e. selective f. differential

a) Supports the growth of a wide variety of organisms such as TBS, TSA, NB, NA... b) When the complete chemical composition of a medium is known c) At least one ingredient is not chemically defined d) Contains growth factors, vitamins, and nutrients to support growth of microbes who can't make them on their own (fastidious) e) Contains ingredients to inhibit growth of certain bacteria to allow others to grow f) Colonies of bacteria or area around colonies looks different to help you tell organisms apart

Chapter 14: Define these terms: a. chemotherapy b. antimicrobial drugs

a) chemotherapy is actually a broader term that refers to any use of chemicals or drugs to treat disease b) typically work by destroying or interfering with microbial structures and enzymes, either killing microbial cells or inhibiting of their growth.

Briefly explain how these methods are used to evaluate the effectiveness of disinfectants and antiseptics: a. Disk-diffusion method b. use-dilution test c. in-use test

a) have nutrient agar plate and swab the entire surface with bacteria that is being tested, then place filter paper disks on agar plate. As the "lawn" of bacteria grows, zones of inhibition of microbial growth are observed as clear areas around the disks. ---larger zones typically correlate to increased inhibition effectiveness of the chemical agent b) The use-dilution test is commonly used to determine a chemical's disinfection effectiveness on an inanimate surface. Take used disinfectant solution and put it in a broth with an inactivator and then take drops and put it on an agar plate and see how many grow into colonies and if it grows into 5+ colonies then it says the disinfectant solution wasn't being that good as a disinfectant c)An in-use test can determine whether an actively used solution of disinfectant in a clinical setting is microbially contaminated

Compare the duration of the illness period for these diseases: a. acute diseases b. chronic diseases c. latent diseases

a) pathologic changes occur over a relatively short time (e.g., hours, days, or a few weeks) and involve a rapid onset of disease conditions (go through stages--> get sick, then really sick, then you get better) Examples: Influenza, colds, etc. b) pathologic changes can occur over longer time spans (e.g., months, years, or a lifetime) c) pathogen goes dormant for extended periods of time with no active replication (Herpes virus infection) disease is still in your body (not 100% gone) but dormant

For these Antifungal drugs, describe the mode of action and the microbes they are used against: (Antifungal Drugs) a) polyoxins

a) they have a cell wall made of chitin so target that inhibit chitin synthesis

Describe the purpose of: a. thioglycolate media b.anaerobic jars/chambers

a) thioglycolate medium containing a low percentage of agar to allow motile bacteria to move throughout the medium. Thioglycolate has strong reducing properties and autoclaving flushes out most of the oxygen. b) The most common approach is culture and is an enclosed box from which all oxygen is removed.

Describe the Mechanism of Action and the viruses inhibited for these drugs: a) Acyclovir b) Etravirine c) Ritonavir d) Raltegravir e) Enfuviritide f) Olsetamivir (Tamiflu)

a) used for Nucleoside analog inhibition of nucleic acid synthesis clinical uses: HIV infections b) used for Non-Nucleoside noncompetitive inhibition clinical uses: HIV infections c) used for the inhibition of protease clinical uses: HIV infections d) used for the inhibition of integrase clinical uses: HIV infections e) used for the inhibition of membrane fusion clinical uses: HIV infections f)used to inhibit neuraminadase clinical uses: infections with influenza virus

For these Antihelminthic Drugs, describe the mode of action and the microbes they are used against: a) Niclosamide

a) used to inhibit ATP production Clinical uses: intestinal tapeworm infections

For these Antiprotozoan Drugs, describe the mode of action and the microbes they are used against: a) Sulfonamide (specific drug name: Sulfadiazine) b) Metronidazole

a) used to inhibit folic acid synthesis clinical uses: malaria and toxoplasmosis and can be transmitted from undercooked meats and cats b) used to inhibit DNA synthesis clinical uses: infections caused by Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis

Define: Membranes disrupting Toxins a) hemolysins b) Leukocidins c) Phospholipases: d) Superantigens

a)Disrupt red blood cell membranes b) form pores in white blood cell membranes c)enzyme but acting as a toxin disrupt phospholipids lysing cell membranes d) trigger an excessive, nonspecific stimulation of immune cells to secrete cytokines causing too many cell signals can cause high fevers low blood pressure, multiorgan failure, shock, and death

1. Define: a. CFU's b. biofilm c. Extracellular Polymeric Substances (EPS) d. planktonic cells e. sessile cells f. autoinducer g. quorum sensing

a)colony-forming units-- rather than cells per milliliter because more than one cell may have landed on the same spot to give rise to a single colony b) complex and dynamic ecosystems that form on a variety of environmental surfaces c) Extracellular polymeric substances (EPSs) are natural polymers of high molecular weight secreted by microorganisms into their environment d) Free-floating microbial cells that live in an aquatic environment are called planktonic e) sessile cells are cells attached to a surface f)enables microorganisms to detect their cell density through the release and binding of small, diffusible molecules called autoinducers g) The mechanism by which cells in a biofilm coordinate their activities in response to environmental stimuli Quorum sensing—which can occur between cells of different species within a biofilm—enables microorganisms to detect their cell density through the release and binding of small, diffusible molecules

Define these physical and/or chemical microbial control protocols: d. asepsis e. sepsis f. disinfection/disinfectant

d) preventing contamination of the patient with microbes and infectious agents e) Body wide infection causing systemic inflammation, high fever, increased heart and respiratory rates, shock, and potentially death f) Not sterile, heat or chemicals kill many microbes on formite surfaces.

For each chemical group listed, indicate the mode of action of microbial control and whether it is sporicidal. For each example, list its common uses and limitations. e. Surfactants: soaps, quaternary ammonium detergents (quats) f. Bisbiguanides: chlorhexidine and alexidine g. Alkylating agents: formaldehyde & formalin; Glutaraldehyde, o-phthalaldehyde (OPA), and ethylene oxide

e) Surfactants: -Lower surface tension of water -Help remove microbes from surfaces How they work: -Interact with nonpolar areas in oil and grease to form emulsions (help things mix better) -Loosen and lift away dirt and microbes -QUATS (quaternary ammonium salts)insert into membrane disrupting it Common examples: Soaps and detergents, QUATs added to Lysol, QUATs added to skin antiseptics, oral rinses, and mouthwash f) Bisbiguanidies: chlorhexidine and alexidine -Cationic molecules with antiseptic properties How they work: -Disrupts cell membrane -Causes congealing of cytoplasmic contents Common examples: Chlorhexidine in surgical soaps, topical antiseptics, and oral rinses g) Alkylating agents: ---Strong disinfectants that can sterilize How they work: Inactivate enzymes and nucleic acids Cross links proteins examples: Formaldehyde: embalming solution Ethylene oxide: sterilization of heat sensitive items β-Propionolactone: sterilization agent for tissue graft and vaccines

Define these physical and/or chemical microbial control protocols: g. antisepsis/antiseptic h. degerming i. sanitization

g) Not sterile, chemicals safe to lower microbial counts on living tissues such as skin and mucus membranes h) Removing microbes from living tissues with the help of scrubbing i) Cleaning fomites so they are safe for the general public

For each chemical group listed, indicate the mode of action of microbial control and whether it is sporicidal. For each example, list its common uses and limitations. h. Peroxygens: hydrogen peroxide, peracetic acid, benzoyl peroxide, ozone gas i. Supercritical Carbon dioxide (scCO2) j. Enzymes: Lysozyme and Prionzyme

h) Peroxygens: -Strong oxidizing agents that can be used as disinfectants, antiseptics, and in high concentration as gaseous sterilizing agents How it works: Produces free radicals that damage organic molecules (ROS) (could get rid of endospores) Common examples: Hydrogen peroxide, Benzoyl peroxide, Carbamide peroxide (toothpaste), Ozone gas (treats water or air) i) Supercritical Carbon dioxide (scCO2) -CO2 brought to pressure 10 x atmosphere -Physical properties between liquid and gas -Can penetrate to sterilize while being nontoxic, nonreactive, and nonflammable How it works: Penetrates cells and forms carbonic acid lower cell's pH Uses: Treat foods Treat tissues before transplant Pest control j) not on slides

Describe the various routes of administration for antimicrobial drugs.

oral- pill form or liquid form depending if you can't swallow pills - lowest concentration that takes the longest time Intramuscular (IM)- an injection in the muscular tissue -next highest concentration takes a longer time Intravenous (IV)- an injection into the veins (blood) - highest plasma concentration of the drug in the shortest amount of time