Lecture 5 Pathogenesis, Role, Diagnosis, Drugs (E1) Flashcards

Question

Diptheria toxin (A-B)

Answer 1

Target Cell Receptor- Growth factor receptor precursor Biological Effects- Inhibition of protein synthesis, cell death

Answer 2

Target Cell Receptor- Tumor endothelial marker-8 (TEM-8); capillary morphogenesis protein 2 (CMG2) Biological Effects- EF + PA: increase in target cell cAMP level, localized edema; LF+PA: death of target cells and experimental animals

Answer 3

Target Cell Receptor- Polysialoganglio sides plus 15-kDa glycoprotein (co-receptors) Biological Effects- Decrease in neurotransmitter release from inhibitory neurons, spastic paralysis

Answer 4

Target Cell Receptor- Polysialogangliosides plus synaptotagmin (co-receptors) Biological Effects- Decrease in peripheral presynaptic acetycholine release, flaccid paralysis

Answer 5

Target Cell Receptor- Ganglioside (GM) Biological Effects- Activation of adenylate cyclase, increase in cAMP level, secretory diarrhea

Answer 6

Lipopolysaccharides in Gram Negative, Induces strong acute-phase response 1. Acute phase response- fever, leukocytosis/leukopenia, disseminated (all around body) intravascular coagulation (DIC), hypotension, Shock and death 2. FDA limit 3. Binding events: Lipid binding protein (LBP, serum) Transfers to CD14 (CR, cell membrane)- MD2 associated with TLR4 which then sends signal to interior cell (acute response Triggered Event(direct or indirect): Production of cytokines LPS activates macrophages to enhanced phagocytosis and cytotoxicity Activation of the complement cascade(C3a, C5a) Histamine, neutrophil chemotaxis (pus) Activation of the coagulation cascade (Factor XII)

Answer 7

Mycobacteria

Answer 8

Strptococci pyogenes, anti-M-protein (during inflammation B-cells attack, but we have similar heart protein so we attack ourselfs)

Answer 9

Chlamydia, Treponema, Borrelia, Streptococci

Answer 10

DIC thrombosis- Disseminated Intravascular coagulation (DIS)

Answer 11

Range of activity of an antimicrobial against bacteria. A broad-spectrum antibacterial drug can inhibit a variety of gram(+) and gram(-) bacteria, whereas a narrow-spectrum drug is active against a limited variety of bacteria

Answer 12

Discovered by Fleming Block cross-linking of peptidoglycan (Transpeptidase) All have Beta-lactam ring Different spectra of action Resistance due to bacterial Penicillinases; (beta-lactamases)

Answer 13

are a class of drugs used to manage and treat various bacterial infections. Azithromycin, clarithromycin, and erythromycin are commonly used to treat infections like pneumonia, sinusitis, pharyngitis, and tonsillitis

Answer 14

Binds 30S subunit of ribosome (irreversible?) Distorts the ribosome Errors translation Derived from Streptomycin and Micromonospora Neomycin (Neosporin Ointment) Relatively broad spectrum because they inhibit protein synthesis(good, still has toxicity problems)

Answer 15

Different ring structure and R groups than Penicillins Derived from Fungus Acremonium Block cross-linking of peptidoglycan All have beta-lactam ring (less susceptible to penicillinases) Different spectra of action (generations) Helps against G(-) outer membrane Broad-spectrum Cause fewer allergic reactions (penicillinases (hapten))

Answer 16

Binds 30S ribosome subunit Inhibit Protein Synthesis Blocks the A site on the ribosome (where the tRNA comes in) Prevents tRNA entry Reversible reaction Bacteriostatic Broad spectrum

Answer 17

Goal of antimicrobial drugs -Disrupt the cell processes or structure of bacteria, fungi, and protozoa -or Inhibit virus replication Most interfere with the function of enzymes required to synthesize or assemble macromolecules or destroy structures already formed Drugs should be Selectively Toxic- They kill or inhibit microbial cells without damaging host tissues (macromolecules, proteins, nucleic acid)

Answer 18

Combinations of antibiotics that may be used to (1) broaden the antibacterial spectrum for empirical therapy or the treatment of polymicrobial infections, (2) prevent the emergence of resistant organisms during therapy, and (3) achieve a synergistic killing effect

Answer 19

Combinations of two antibiotics that have enhanced bactericidal activity when tested together compared with the activity of each antibiotic alone

Answer 20

Combination of antibiotics in which the activity of one antibiotic interferes with the activity of the other (e.g. the sum of the activity is less than the activity of the most active individual drug)

Answer 21

Antibiotic that inhibits the growth of bacteria but does not kill

Answer 22

Antibiotic that kills bacteria

Answer 23

Determined by exposing a standardized suspension of bacteria to a series of antimicrobial dilutions. The lowest antibiotic concentration that inhibits the growth of the bacteria is the MIC- what we need to achieve

Answer 24

Determined by exposing a standardized suspension of bacteria to a series of antimicrobial dilutions. The lowest antibiotic concentration that kills 99.9% of the population is referred to as the MBC

Answer 25

An enzyme that hydrolyzes the beta-lactam ring in the beta-lactam class of antibiotics, thus inactivating the antibiotic. The enzymes specific for penicillins, cephalosporins, and carbapenems are the penicillinases, cephalosporinases and carbapenemases, respectively Degrades penicillin

Answer 26

Cell wall inhibitors- Block synthesis and repair of peptidoglycan Cell Membrane- Cause loss of selective permeability (Polymyxins, Daptomycin) DNA/RNA- Inhibit replication and transcription; Inhibit gyrase (unwinding enzyme) (Quinolones, Inhibit RNA polymerase, Rifampin)-Very few drugs Protein synthesis inhibitors acting on ribosomes (site of action 50s, 30s and both) Folic acid synthesis- Block pathways and inhibit metabolism (Sulfa drugs)

Answer 27

Ways microbes have built drug resistance Plasmid- Acquisition of entire new genes or sets of genes via transfer from another species (plasmids, called resistance (R) factors) Spontaneous mutations in critical chromosomal genes

Answer 28

Porins allow for the passive diffusion of water, ions, and other small molecules. They also help maintain osmolarity, transport nutrients and salts, and contribute to virulencePorin expression is regulated by several mechanisms, including β-barrel assembly machinery and lipopolysaccharide binding. Antibiotic resistance Adaptations that reduce the influx of compounds through porins can contribute to the emergence of antibiotic resistance

Answer 29

Crucially part of penicillin, screws up cross-linking in the cell wall

Answer 30

are transport proteins involved in the extrusion of toxic substrates (including virtually all classes of clinically relevant antibiotics) from within cells into the external environment. These proteins are found in both Gram-positive and -negative bacteria as well as in eukaryotic organisms.

Answer 31

1st Generation more gram positive 2nd 3rd 4th 5th Generation more gram negative

Answer 32

An enzyme specific the penicillinases

Answer 33

Inhibits cross-linkage of peptidoglycan layers

Answer 34

Methicillin-resistant Staphylococcus aureus (MRSA) infection is caused by a type of staph bacteria that's become resistant to many of the antibiotics used to treat ordinary staph infections

Answer 35

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a type of MRSA infection that can affect anyone, but some people are at higher riskMRSA infections in healthy people who have not been hospitalized or had a medical procedure (such as dialysis or surgery) within the past year

Answer 36

Inhibition of Nucleic Acid Synthesis -Prevent transcription by binding DNA-Dependent RNA polymerase This is a difficult target because the process is well conserved (similar process and enzymes for most life forms) Specific for bacteria- favorable therapeutic index Prevents elongation of transcript after initiation Useful drug for tuberculosis Resistance can develop quickly

Answer 37

an antifungal used to treat fungal infections in neutropenic patients, cryptococcal meningitis in HIV infection, fungal infections, and leishmaniasis binds sterols in cell membranes with a higher affinity toward ergosterol than mammalian cholesterol. As the concentration of the drug increases in organs such as the kidney, it begins to bind cholesterol in mammalian membranes, leading to nephrotoxicity

Answer 38

may cause decreased kidney function and liver problems. In addition, this medication may decrease bone marrow function. This serious, possibly life-threatening side effect may lead to a low number of blood cells such as red cells, white cells, and platelets. -used in combination with other medicine (eg, amphotericin B) to treat serious fungus infections, including Candida infections (eg, septicemia, endocarditis, urinary tract infections) or Cryptococcus infections (eg, meningitis, lung infections) enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA

Answer 39

Inhibition of Protein synthesis- Prevent polypeptide elongation at 30S ribosome Blocks the A site on ribosome (where tRNA comes in) Prevents tRNA entry REVERSIBLE reaction Bacteriostatic Broad spectrum

Answer 40

(Some people took for allergies/no tired) Large lactone ring with sugars attached relatively broad-spectrum Fairly low toxicity (heart arrythmyia with Seldane) Blocks protein synthesis by attaching to the 50S ribosome subunit Mycoplasma pneumonia, legionellosis, Chlamydia infections, pertussis, diphtheria

Answer 41

Using Rifampin, Binds to bacterial RNA polymerase mRNA sythesis

Answer 42

Disruption of cell wall- Inhibits mycolic acid synthesis

Answer 43

Often given with Trimethoprim, One of the primary treatments for Pneumocystis (carinii) Jiroveci pneumonia (PCP) in AIDS patients

Answer 44

Antimetabiolite- Inhibits dihydrofolate reductase and disrupts folic acid synthesis Sulfa drug THF is an important co-enzyme (we need but get in food, bacteria synthesize)- folic acid

Answer 45

DNA Replication- Few clinical drugs affect polymerization Mechanisms are conserved: lead to toxicity DNA gyrase inhibitors (DNA unwinders)

Lecture 5 Pathogenesis, Role, Diagnosis, Drugs (E1) Flashcards

Ch 14, 15, 16, 17