MCB Final Exam Study Guide
What cells structures/functions do bactericidal drugs tend to target as compared to bacteriostatic drugs?
Bacteriostatic drugs target bacterial protein synthesis and metabolic pathways like folic acid production (things for growth growth) Bactericidal drugs target cell walls, cell membranes, or nucleic acids (to kill)
Know the features of B cells. (Be able to select the true and/or false statements about them form a list)
-humoral branch adaptive immunity mediated -include plasma cells (activated B cells that make antibodies) -mature in the bone marrow -found mainly in lymphatic tissues -B cell receptors, which are secreted as antibodies following B cell activation -do not require antigen presenting cell to become activated -memory cells made after activation -MHC1 and 2 present on cell surface -considered an antigen presenting cell
Know the features of eukaryotic extracellular and intracellular structures
-plasma membrane -glycocalyx -Rough ER -Nucleus -Smooth ER -Mitochondrion -Ribosome -Lysosome -Centrisome -Cytoplasm -Golgi apparatus -Flagellum
Know the features of T cells. (Be able to select the true and/or false statements about them form a list)
- cellular branch of adaptive immunity include: -T helper cells (CD4+ or TH) stimulate B cells and other leukocytes -T cytotoxic (CD8+ and TC) cells: seek and destroy cancer cells and other cells infected with intracellular pathogens -mature in the thymus -found mainly in lymphatic tissues -antigen recognition receptors are TCRs -require antigen presenting cell to become activated -memory cells made after activation -MHC 1 proteins present -not an antigen presenting cell
Know the features of prokaryotic extracellular and intracellular structures
- nucleoid -ribosomes -capsule or slime layer -cell wall -plasma membrane -pillus (mobility) -cytoskeleton -Flagellum -fimbriae
What is hemolytic disease of the newborn and in what scenario may it develop?
A disease in which an Rh+ baby's red blood cells are lysed in response to maternal anti-Rh antibodies that cross the placenta; the lysis induces a severe and possibly fatal anemia in the baby.
Understand the features of rifamycins
A group of bactericidal drugs that were originally isolated from bacteria. They are now mainly produced as synthetic and semisynthetic compounds. Rifampin is a key example. it inhibits transcription by binding to RNA polymerase, broad spectrum, Gram positive and gram negative. Useful to combat mycobacterial species when challenging to get drugs across rich waxy mycolic-acid enriched cell wall. often administered as part of combination therapy. take care because its presence inhibits a number of drugs.
What is the definition of a true pathogen?
A pathogen that does not require a weakened host to cause disease.
Understand how the Gram stain works
A staining procedure that allows us to classify bacteria as either Gram-positive or Gram-negative; Following the Gram staining procedure, Gram-positive cells appear purple while Gram-negative bacteria appear pink; the final outcome of the Gram stain is based on the cell wall properties of the stained cells.
Know what makes for a compatible versus incompatible blood transfusion--be able to tell what sort of blood type a given patient could receive as a successful transfusion.
AB+: universal recipient, AB-: cannot have Rh (+) A+: Cannot have B A-: cannot have B or Rh (+) B+: cannot have A B-: cannot have A or Rh (+) O+: cannot have A or B O-: only O-, universal donor
What is/are the main difference(s) between anaerobic and aerobic respiration?
Aerobic cellular respiration uses oxygen as the final receptor, while anaerobic cellular respiration does not. Aerobic respiration is a set of metabolic reactions that take place in the presence of oxygen, occurring in a cell to convert chemical energy into ATPs. Anaerobic respiration is a process of cellular respiration where the high energy electron acceptor is neither oxygen nor pyruvate derivatives
What drugs are used to treat malaria?
Antimalarial drugs such as Chloroquine, Quinine, and artemisinin-based combination therapies (ACT) are used to treat malaria. Tetracyclines can be used to prevent malaria.
How are agglutination tests used to determine blood type?
Agglutination will only occur if antibodies interact with antigens on the red blood cell surface. By adding antibodies that detect A or B antigens, a person's red blood cell antigens can be determined.
Understand what happens in the Krebs cycle and the major energetic benefit of the Krebs cycle.
Also called citric acid cycle or the tricarboxylic acid cycle; this cycle is a series of redox reactions and decarboxylation reactions that begins with the formation of citric acid from oxaloacetic acid and the acetyl-CoA made in the intermediate step; the Krebs cycle produces some ATP and a lot of the reduced cofactors NADH and FADH2.
Understand how antigenic shift contributes to pandemics.
Antigenic shift is a major genetic reassortment that dramatically changes the virus; often leads to viral strands with new features. This contributes to pandemics because people will have no residual immune protection from prior vaccinations. limited preexisting immunity.
Understand what narrow spectrum drugs are versus broad spectrum drugs.
Broad spectrum drugs are affective against both Gram negative and Gram positive bacterial cells. Narrow spectrum drugs target a limited range of bacteria. cause less disruption to the normal microbiota than broad spectrum drugs.
Understand the following terms as they relate to viruses: broad tropism, narrow tropism, broad host rang, narrow host range.
Broad tropism: a broad preference of a pathogen for a specific host or tissue. Narrow Tropism: specific tissue or host that a pathogen targets Broad Host range: the collection if species that a pathogen can infect is broad; many Narrow host range: pathogen can only infect certain species
Know the various bacterial shapes and arrangements.
Coccus (circular) single, diplo (2), Strep (chain), Staph (cluster) Baccilus (rod) Single, diplo(2), Strep (chain), Pallsades (cluster)
Know what DNA replication is and when do cells perform it.
DNA replication is the process by which a cell copies its genome before it divides.
Compare and contrast DNA to RNA.
DNA is the genetic material in all cells; made of repeating subunits called nucleotides and exists as a double stranded helical molecule. Cells have this. RNA is a nucleic acid made of repeating subunits called nucleotides, which are made up of a phosphate, a sugar (ribose), and one of 4 possible nitrogen bases (A,U,G,or C). Viruses can have DNA or RNA.
What are DNA microarrays and what can they reveal?
DNA microarrays are a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome.
Understand the features of endosymbiotic theory to include the evidence that supports the theory.
Describes the evolution of eukaryotes as a series of sequential, cell-merging events between an ancient eukaryotic ancestor and certain prokaryotes. Evidence shows that eukaryotes evolved from prokaryotes based on mitochondria and chloroplasts seeming to have once been independent prokaryotic lifeforms (they have their own DNA, double membrane structure.
Know the various modes of direct and indirect infection transmission
Direct: person to person (saliva, touching, sex), Animal bite or scratch, Environment (swimming), Vertical (in utero, vaginal delivery, breast milk) Indirect: airborne (respiratory droplets), vehicle (contact with contaminated objects), biological vector (mosquito, tick, flea bite), Mechanical vector (pathogen hitches a ride fly or cockroach)
Understand the oxygen conditions under which a facultative anaerobe can grow. Under what oxygen concentrations would such a microbe grow best?
Facultative anaerobes are a group of microbes that spans both aerobic and anaerobic environments; can use oxygen for their metabolism, but if needed, they can perform anaerobic metabolism when oxygen is absent. show better growth when oxygen is present, but can grow without it.
Thoroughly compare and contrast Gram-positive and Gram-negative bacteria--to include knowing which structural features you would see in Gram-positive versus Gram-negative bacteria
Gram Positive: appear purple, thick layer of peptidoglycan Gram Negative: appear pink, thin layer of peptidoglycan
Based on how penicillin works, what class of bacteria would you expect to be more susceptible to penicillin's effects?
Gram positive bacteria
What is herd immunity and how does it protect populations from disease outbreaks
Herd immunity is communal immunity that occurs when a pathogen won't find enough susceptible people in the community to persist, even if a small number remain unvaccinated.
How does adaptive immunity differ from innate immunity?
Innate immunity (non-specific immunity) is an inborn, ancient protection existing in one form or another in all eukaryotic organisms; these generalized responses don't vary based on the pathogen being fought. Adaptive immunity (specific immunity) or acquired immunity are our 3rd and final line of defense. responses mature over time and are tailored to pathogens that are encountered and may exhibit immunological memory.
Understand the bacterial growth curve and what is occurring at each stage in the curve.
Lag: cells adjust to their environment Log: exponential cell growth Stationary: number of cells dividing = number if cells dying Death: cells die as waste accumulates and nutrients are depleted
Understand what is meant by the terms natural, synthetic, and semisynthetic antimicrobial compounds.
Natural: naturally occurring antimicrobial compounds Synthetic: antimicrobials that are wholly manufactured by chemical processes Semisynthetic: naturally occurring antibiotics that can be chemically modified to improve their pharmacological actions and/or stability
Describe the various portals of pathogen entry.
Otic: ear Ocular: eye Skin:bore through skin Respiratory mucosa Parenteral: bites cuts injections GI mucosa: fecal/oral Urogenital/reproductive system: sex Transplacental: mom to baby
What are the pros and cons of an inactivated vaccine?
PROs: stable at room temperature, easy to ship and store, safe for immunocompromised patients CONs: lack if infectivity means they are quickly cleared from the body, which limits exposure to the antigens and necessitates booster doses to achieve full immunity.
Understand the features of quinolones as well as their pros and cons.
Quinolones are synthetic antimicrobials that target DNA replication enzymes, namely DNA gyrase and topoisomerase. These drugs are not usually used in first line therapies, and instead reserved for treating infections that show antimicrobial resistance. Pro: fluroquinolones are broad spectrum, can be taken orally, and have a relatively ling half-life. They are excellent in situations where they're isn't time to identify the pathogen. Cons: side affects are gastrointestinal upset (nausea, diarrhea, vomiting), headache dizziness, insomnia (resolve upon finishing drug course). Also associated with serious side effects such as nerve damage, tendonitis, and possible tendon rupture.
Know the basic shortcomings of the following drug classes: phenicols, lincosoamides, aminoglycosides, tetracyclines, and macrolides
Shortcomings of: Phenicols: narrow therapeutic index and is associated with bone marrow toxicity Lincosamides: clindamycin has an antimicrobial agent that is commonly associated with pseudomembranous colitis caused by C Diff Aminoglycosides: poor adsorption through intestines and their short half-life of 2 to 3 hours. Non-topical ahminoglycosides are known to cause hearing loss, nephrotoxicity Tetracyclines:increased risk of C Diff, photosensitivity, and in children under 8 it detrimentally effects bones and teeth Macrolides: broad spectrum; no shortcomings listed :(
Thoroughly compare and contrast prokaryotic and eukaryotic cells--to include what organelles each has as well as extracellular features.
Similarities: both have a cell membrane, DNA, ribosomes, and cytoplasm Differences: Prokaryotic Cell: reproduce by binary fission, DNA in circular form. Features are cell wall, cell membrane, capsule, ribosome, DNA, flagellum, pilli (rotary motion) Eukaryotic Cell: Multicellular, larger, membrane bound nucleus, linear DNA with histones. sexually reproduce by mitosis. Features are nucleus, mitochondrion, smooth ER, Rough ER, Golgi apparatus, peroxisome, lysosome, Flagella (wavelike motion)
Understand the various types of mutations and their potential consequences (e.g., insertion, deletion, base substitution, etc.)
Substitution: mutations that occur when an incorrect nucleotide is added. Consequences: silent, nonsense (change leads to a stop signal instead of an amino acid), or missense (a new codon encodes the iron amino acid) Insertion: mutations that occur earn a cell adds one or more nucleotides to its genome sequence. Deletion: mutations that occur when one or more nucleotides are removed from a DNA sequence Insertions and deletions can shift the mRNA reading from and lead to drastic changes in the resulting protein
What is the purpose of the streak plate technique?
Technique that helps to isolate a specific species of microbe for study, accomplished by spreading the sample thinly enough on an agar plate, so that the various cells in the sample are sufficiently separated and can give rise to individual colonies.
Understand the structural and functional features of endospores and state why endospores are problematic in clinical settings
The capacity to make endospores allows dangerous pathogens to survive for for extended periods on surfaces, even in healthcare settings that work hard to eradicate them.
Understand what a primary immunodeficiency is and how it differs from an acquired immunodeficiency.
The lack of a properly functioning immune system can be primary (inborn) or secondary (acquired)
Right now COVID-19 disease is considered "reportable"...this is true for a list of other diseases too. If a healthcare provider makes a confirmed diagnosis for a reportable disease, to whom are they legally required to report the case?
The state health department
Understand how vaccines trigger immune responses for longer term protection.
The vaccine elicits a strong adaptive immune response that specifically recognizes the pathogen and induces long-term immunological memory.
Understand the features of beta-lactam drugs as well as their pros and cons...and be able to name the key beta-lactam subgroups.
This superfamily of antibacterial drugs work by blocking cell wall construction; includes penicillins, cephalosporins, carbapenems, and monobactams. Features: 4 sided beta lactam ring as part of their chemical structure, bind to transpeptidase enzymes that are central to building peptidoglycan. Pro: most bacterias have cell walls consisting of peptidoglycan so this group would work to combat it Cons: many bacteria make beta lactamases which are enzymes that inactivate beta lactam drugs, so inhibitors have to be coadministered
What is the main goal of the first line of immune defenses?
To prevent the pathogen from ever entering the body.
Understand the features of the four types of hypersensitivities and what immune system factors (e.g. cell type or antibody type/s) govern each type of hypersensitivity.
Type 1: Allergies. driven by IgE interacting with soluble antigens, not associated with autoimmunity Type 2: Cytotoxic (often but not exclusively so), driven by IgG ir IgM interacting with non-soluble antigens on cell surface. drugs can trigger a response and it is associated with autoimmunity Type 3: Immune Complex, driven by IgG or IgM interacting with soluble antigens, drugs can trigger a response, associated with autoimmunity, autoimmune disorders Type 4: Delayed hypersensitivity, driven by T cells interacting with soluble or cell or matrix bound antigens, drugs can trigger the response, associated with autoimmunity. skin reactions and certain autoimmune disorders.
Understand the acid-fast stain--how it generally works and what it detects.
acid fast staining distinguishes between cells with and without waxy mycelia acid cell walls. The most common acid-fast staining procedure is the Ziehl-Neelsen method. Acid-fast bacteria appear pink and non-acid-fast bacteria are blue.
What are sulfa drugs and why do they not target mammalian cells?
among the first synthetic antimicrobials used to combat bacterial infections; competitive inhibitors of folic acid production, are bacteriostatic, and have broad spectrum action. They do not target mammalian cells because mammals cannot produce their own folic acid, thus they do not have the enzyme these drug targets.
What is and adjuvant and why would it be added to a vaccine?
an adjuvant is a pharmacological additive that enhances the body's natural immune response to an antigen. These are added to encourage antigen uptake and processing by antigen-presenting cells.
Understand the steps in animal virus replication and which steps differ (and how they differ) for naked versus enveloped viruses.
animal virus replication have 6 general steps: attachment, penetration, uncaring, replication, assembly, and release. Naked viruses attach to host cell membranes through capsid proteins. enveloped viruses use spikes. In uncaring, enveloped viruses fuse to the cell membrane, while naked viruses are engulfed into the vesicle.
Why are attenuated vaccines typically considered strong stimulators of the immune response?
attenuated vaccines contain active virus of live bacterium rendered nonpathogenic. These vaccines are the closest to the actual agent encountered in nature and tend to stimulate a potent immunological response accompanied by long-lived memory.
Describe conjugate vaccines and state what antigens they tend to be most useful against? Can you give an example of a conjugate vaccine?
conjugate vaccines are vaccines created by linking polysaccharides to a protein antigen to stimulate an immune response. examples of conjugate vaccines are bacterial meningitis, pneumococcal vaccines against Streptococcus pneumonia, Hib vaccines that prevent infections by Haemophilus influenzae type B bacteria.
What is the primary difference between a disinfectant and an antiseptic
disinfectants are germicides used to treat inanimate objects, antiseptics are a class of germicides applied to living tissue such as skin.
Know the key difference between lytic and lysogenic bacteriophage replication cycles.
in Lytic replication, there is attachment, penetration, replication, assembly, and release. In Lysogenic replication, there is attachment, penetration, integration, cell division, and then it enters back into the lytic cycle for replication, assembly, and release. With the cell division, multiple cells not carry the phage genome.
Understand the following terms: mortality, morbidity, endemic.
mortality: An epidemiological measure of association that indicates the number of deaths during a specific time period. morbidity:Presence of a disease in a population. endemic: Describes infections that are routinely detected in a population or region.
Know the types of symbiotic relationships.
mutualism: symbiotic relationship that helps the host Parasitism: symbiotic relationship that hurts the host Commensalism: symbiotic relationship that has no perceived cost to benefit to the host
What is mycolic acid and what bacteria have it in their cell wall?
mycelia acid is a substance in the waxy cell walls of acid fast bacteria. Nocardia and Mycobacterium are the best known examples of acid fast bacteria.
How do polypeptide drugs work?
polypeptide drugs overcome the selective outer membrane of Gram negative cells. They interact with lipopolysaccharide and destabilize the outer membrane of the Gram negative cell wall. they can further destabilize the plasma membrane to cause cytoplasmic leakage and cell lysis.
What is RT-PCR and what does it help us detect?
reverse transcription PCR is useful in detecting RNA in a sample, such as the genome of an RNA virus.
What does the term metabolism mean?
the chemical reactions that organisms use to break down substances to release energy, as well as reactions that use the released energy to build new substances.
What is an attenuated pathogen?
term applies to pathogens they lose virulence factors needed ti cause disease; they are still infectious, but weakened to the point that they don't cause diseases in an immune competent host; may be used to formulate certain vaccines.
What is a pandemic?
worldwide outbreak of disease
