Microbio Ch 12

Microbiology Chapter 12 - drugs, microbes, host - the elements of chemotherapy

antibiotic producing microbes include =

Streptomyces, Bacillus, Penicillium, and Cephalosporium

destabilize the formation of the cell wall causing bacterial cells to lyse; inhibits transpeptidase - activity of which drug?

penicillin

vancomycin and bacitracin are what type of drug with what mode of action?

non beta-lactam cell wall inhibitors

interact with phospholipids of the outer membrane- serious side effects; particularly affects gram negative - activity of what drug?

polymixin

aminoglycosides examples

streptomycin and gentamicin

are metabolic analogs of PABA and block folic acid synthesis =

sulfonamides

nitrogenous base + sugar =

nucleoside

disrupt DNA and RNA replication and cause point mutations

nucleotide analogs

enzyme that digests or breaks down protein

protease

drug that treats AIDS by blocking the production of protease, a proteolytic enzyme that helps create new viral pieces for HIV

protease inhibitor

proteins (cytokines) secreted by T cells and other cells to aid and regulate the immune response; second line of defense

interferons

helps release virions from the host cell after replication and assembly

neuraminidase

telitromycin (Ketek), new drug with different ring structure from Erythromycin; used for infection when resistant to macrolides

ketolides

linezolid (Zyvox); synthetic antimicrobial that blocks the interaction of mRNA and ribosome

Used to treat methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus (VRE)

Oxazolidinones

common metabolic products of aerobic bacteria and fungi that inhibit other microbes

antibiotics

antibiotics can inhibit and/or kill bacteria in the genera _____ and _____

streptomyces, bacillus

antibiotics can inhibit and/or kill mold in the genera _____ and _____

penicillium, cephalosporium

drugs that inhibit or kill microbial cells without simultaneously damaging host tissues are described as =

selectively toxic

cell wall inhibitors, cell membrane, DNA/RNA, protein synthesis inhibitors acting on ribosomes, and metabolic pathways and products are all examples of drug _____

mechanism of action

decrease in the prevalence of infectious disease is the direct effect of _____

antibiotics

a drug’s _____ is its range of activity

spectrum

drugs that are effective on a small range of microbes are described as =

narrow-spectrum

_____ drugs target a specific cell component that is found only in certain microbes =

narrow-spectrum

drugs that are effective on a large range of microbes are described as =

broad-spectrum

_____ drugs target cell components common to most pathogens (ribosomes)

broad-spectrum

_____ and _____ block synthesis of peptidoglycan, causing the cell wall to lyse

penicillins, cephalosporins

penicillins and cephalosporins block synthesis of _____, causing the cell wall to luse

peptidoglycan

penicillins that do not penetrate the outer membrane are less effective against _____ bacteria

gram-negative

broad spectrum penicillins and cephalosporins can cross the cell walls of _____ bacteria

gram-negative

beta-lactam antimicrobials primary mode of action is =

interfere with cell wall synthesis

_____ antimicrobials primary mode of action is to interfere with cell wall synthesis

beta-lactam

greater than half of all antimicrobial drugs are _____

beta-lactam

_____ _____ _____ of all antimicrobial drugs are beta-lactams

greater than half

the most prominent beta-lactams are _____ and _____

penicillins, cephalosporins

the most prominent _____ are penicillins and cephalosporins

beta-lactams

enzyme that inactivates penicillins

penicillinase

all penicillins consist of 3 structurally similar parts: _____, _____, _____

thiazolidine ring, beta-lactam ring, variable side chain

cephalosporins account for _____ of all antibiotics administered

one third

_____ account for one third of all antibiotics administered

cephalosporins

cephalosporins have a synthetically altered _____ structure

beta-lactam

_____ are relatively broad-spectrum, resistant to most penicillinases, and cause fewer allergic reactions

cephalosporins

4 generations of _____ exist, each more effective against gram-negatives than the one before, with improvised dosing and fewer side effects

cephalosporins

_____ generations of cephalosporins exist, each more effective against _____ than the one before, with improvised dosing and fewer side effects

4, gram-negatives

first generation of cephalosporins is most effective against =

gram-positive cocci, few gram-negative

Second generation of cephalosporins is most effective against =

gram-negative bacteria

Third generation of cephalosporins is most effective against =

enteric bacteria with beta-lactamases

Fourth generation of cephalosporins is most effective against =

widest range, gram-negative and gram positive

vancomycin is _____, most effective against _____, is _____ and _____ to administer

broad-spectrum, staphylococci, toxic, hard

_____ is broad-spectrum, most effective against staphylococci, is toxic and hard to administer

vancomycin

_____ is narrow-spectrum, produced by a strain of bacillus subtilis, used topically in ointment

bacitracin

bacitracin is _____, produced by a strain of _____ _____, and is used _____ _____ _____

narrow-spectrum, bacillus subtilis, topically in ointment

polymyxin mode of action

cell membrane

polymyxins interact with _____ and cause _____ particularly in _____ bacteria

phospholipids, leakage, gram-negative

_____ interact with phospholipids and cause leakage, particularly in gram-negative bacteria

polymyxins

amphotericin B and nystatin form _____ _____ _____ on _____ membranes, which cause _____

complexes with sterols, fungal, leakage

_____ and _____ form complexes with sterols on fungal membranes, which cause leakage

amphotericin B, nystatin

amphotericin B and nystatin mode of action

cell membrane

drugs that block protein synthesis can also damage the _____ _____

eukaryotic mitochondria

drugs that block _____ could also damage the eukaryotic mitochondria

protein synthesis

_____ cause misreading of mRNA by changing the A-site conformation, blocking protein synthesis

aminoglycosides

aminoglycosides cause misreading of _____ by changing the _____ _____, blocking protein synthesis

mRNA, A-site conformation

aminoglycoside mode of action

protein synthesis

_____ block attachment of tRNA on the A acceptor site and stop further protein synthesis

tetracyclines

tetracyclines block _____ _____ _____ on the _____ _____ _____ and stop further _____ _____

attachment of tRNA, A acceptor site, protein synthesis

tetracycline mode of action

protein synthesis

STDs, rocky mountain spotted fever, lyme disease, typhus, acne, and eukaryotic parasites are all conditions/microbes that can be treated with which antimicrobial drug?

tetracycline

tetracycline spectrum =

broad, gram-positive and gram-negative

drugs that block metabolic pathways by competing with normal substrate for enzyme’s active site =

competitive inhibition

drugs that block metabolic pathways by having a more powerful effect in combination with each other than the sum of the effects of the individual drugs

synergistic effect

sulfonamides and trimethoprim mode of action

block metabolic pathways

sulfonamides and trimethoprim spectrum

narrow-spectrum

shigellosis, UTI, protozoan infections, burns, eye infections, PCP are all conditions/microbes that cam be treated with what drug(s)?

sulfonamides and trimethoprim (metabolic pathway inhibitors)

drugs that affect nucleic acid synthesis may block synthesis of _____, inhibit _____, or stop _____

nucleotides, replication, translation

antibacterials, antivirals, and antiprotozoan drugs are examples of drugs that affect _____ _____ synthesis

nucleic acid

chloroquine binds and cross-links the _____ _____ to treat _____ infections

double helix, malaria

_____ binds and cross-links the double helix to treat malaria infections

chloroquine

quinolones do what

inhibit DNA helicases

quinolones mode of action

nucleic acid synthesis

chloroquine mode of action

nucleic acid synthesis

one complication of antiviral chemotherapeutic agents is that _____ _____ is almost impossible due to the fact that viruses are obligate intracellular parasites

selective toxicity

why can’t antiviral chemotherapeutic agents be selectively toxic?

viruses are obligate intracellular parasites

actions of what type of drug include blocking penetration into host cell, blocking replication, transcription, or translation of viral genetic material via nucleotide analogs, inhibit proteases, and prevent maturation of viral particles?

antiviral chemotherapeutic agents

many _____ _____ mimic the structure of nucleotides and compete for sites on replicating DNA

antiviral agents

many antiviral agents mimic the structure of _____ and compete for sites on _____ _____

nucleotides, replicating DNA

acyclovir is an example of what

antiviral agent

_____ is the first drug aimed at treating AIDS, and is a thymine analog

Azidothymidine (AZT)

Azidothymidine (AZT) is the first drug aimed at treating _____, and is a _____ _____

AIDS, thymine analog

drugs that are human-based glycoproteins produced primarily by the second line of immune defense - made my fibroblasts and leukocytes =

interferons (IFN)

therapeutic benefits of _____ include: reduced healing time, reduced complications of some infections, prevents or reduces symptoms of cold and papillomavirus, slows progression of certain cancers, leukemias, and lymphomas, treats hepatitis C, genital warts, and kaposi’s sarcoma

interferons (IFN)

amantadine, rimantadine, relenza, and tamiflu are drugs used to treat _____

influenza

amantadine and rimantadine are restricted almost exclusively to _____ infections, and prevent _____

influenza A, fusion of virus with cell membrane

_____ and _____ are restricted almost exclusively to influenza A infections, and prevent fusion of virus with cell membrane

amantadine, rimantadine

relenza and tamiflu are _____ _____ drugs which block _____ in influenza A and B

broad-spectrum, neuraminidase

_____ and _____ are broad-spectrum drugs which block neuraminidase in influenza A and B

relenza, tamiflu

ketolides and oxazolidinones are newly developed _____ _____ _____

classes of antimicrobials

ketolides are most effective against gram-_____ infections in the _____ _____

positive, respiratory tract

_____ are most effective against gram-positive infections in the respiratory tract

ketolides

_____ are synthetic, broad-spectrum antimicrobials that block the interaction of mRNA and ribosome

oxazolidinones

oxazolidinones are synthetic, _____ _____ antimicrobials that block the interaction of _____ and _____

broad-spectrum, mRNA, ribosome