Ch. 12: Principles of Antimicrobial Therapy
When a patient is prescribed erythromycin, which of following could reasonably occur?
Bacterial cells resistant to erythromycin because of an alteration in their ribosomal structure would be selected for, giving rise to an entire population of resistant cells.
Why has the United States and Europe banned the use of human drugs in animal feeds?
Because it contributes to the growing drug resistance problem.
Identify the active part of the penicillin structure. Phenol Beta-lactam ring Thiazolidine Benzene
Beta-lactam ring
Which of the following enzymes secreted by certain bacteria cleaves the beta-lactam ring of penicillins and provides for resistance against the antibiotic? Beta-lactamase Gamma interferon Lipase DNA polymerase Lactase Penicillinase
Beta-lactamase Penicillinase
Which of the following describes the cephalosporins? Most taken orally Broad-spectrum Most resistant to penicillinase Most injected into a muscle or a vein Most administered parenterally Narrow-spectrum
Broad-spectrum Most resistant to penicillinase Most injected into a muscle or a vein Most administered parenterally
One approach to deal with microbes known to be drug resistant is to do which of the following?
Combined therapies
Which type of inhibition of an enzyme occurs when the enzyme is blocked from action after a substance that mimics the normal substrate binds to the active site?
Competitive
Resistance factors are shared among bacteria by which of the following processes? Transfection Conjugation Transduction Transformation
Conjugation Transduction Transformation
Antibiotics that disrupt nucleic acid synthesis do so by targeting components of which processes? DNA replication Translation Transcription Folic acid pathway Cell wall synthesis
DNA replication Transcription
Which antimicrobic does not inhibit cell wall synthesis? Vancomycin Gentamicin Cephalosporins Penicillins Clavamox
DO NOT: Gentamicin DO: Ampicillin Vancomycin Cycloserine Penicillins
________ is the most active sulfone and is usually given in combination with rifampin and clofazimine.
Dapsone
What is a major side effect of tetracyclines?
Deposition in hard tissues. Reason: Gastrointestinal disruption and the staining of teeth (hard tissues) are the main side effects of tetracycline.
Which of the following is a macrolide antibiotic that is composed of a lactone ring?
Erythromycin
Which two of the following antibiotics are used to treat tuberculosis? Ethambutol Bacitracin Neomycin Penicillin G or V Isoniazid
Ethambutol Isoniazid
Antimicrobial drugs that block bacterial protein synthesis could also affect which of the following in the host cell?
Eukaryotic mitochondria
An antibiotic that was "pharmed" directly from a microorganism is considered semisynthetic. T/F
F
Ciprofloxacin is used to treat viral respiratory infections. T/F
F
True or false: Most cephalosporins are administered orally.
F
True or false: Natural selection for drug-resistant forms of bacteria is rare.
F
True or false: Drug resistance only arises from an organism gaining the genetic information for the resistance from another organism.
F It can also happen from sponntaneous mutations
True or false: Aminoglycosides are very narrow-spectrum antibiotics.
F Reason: These were the first broad-spectrum antibiotics, targeting the ribosomal subunit to inhibit protein synthesis.
A narrow-spectrum antimicrobial would be an appropriate choice to treat an abscess caused by several different microbe species, including both gram-negative and gram-positive bacteria. T/F
False
How does the practice of routinely feeding antibiotics to farm animals to make them grow more rapidly and become larger contribute to antibiotic resistance?
Farm animals mutate faster than humans so resistance will grow much more rapidly.
Which of the following cephalosporins are considered broad-spectrum antibiotics? First-generation Second-generation Fourth-generation Third-generation
Fourth-generation Third-generation
Which of the following cephalosporins are considered broad-spectrum antibiotics? Fourth-generation First-generation Third-generation Second-generation
Fourth-generation Third-generation
Which of the following are aminoglycosides that insert on sites of the 30S subunit and cause the misreading of the mRNA? Gentamicin Streptomycin Penicillin Tetracyclines
Gentamicin Streptomycin
Which of the following are aminoglycosides that insert on sites of the 30S subunit and cause the misreading of the mRNA? Penicillin Tetracyclines Gentamicin Streptomycin
Gentamicin Streptomycin
Rifampin is used mainly to treat infections caused by which of the following? Fungi Gram-negative bacteria Protozoa Gram-positive bacteria
Gram-positive bacteria
Clarithromycin controls infections and ulcers caused by which of the following bacteria?
Helicobacter pylori
Advantages of semisynthetic penicillins over natural penicillins include which of the following? Increased spectrum Increased movement across gram-negative cell walls Increased susceptibility to penicillinases Decreased allergic reactions
Increased spectrum Increased movement across gram-negative cell walls
Which two semisynthetic penicillins can be used against Gram-negative bacteria? Nafcillin Ampicillin Dicloxacillin Amoxicillin
Ampicillin Amoxicillin
Which of the following antibiotics inhibit bacterial cell wall synthesis? Streptomycin Ampicillin Vancomycin Erythromycin Cycloserine
Ampicillin Vancomycin Cycloserine
Which of the following is a substance produced by natural metabolic processes of some microorganisms that can inhibit or kill other microorganisms?
Antibiotic
___________ chemotherapy is the use of chemotherapeutic drugs to control infections and diseases caused by many types of microorganisms.
Antimicrobial
Erythromycin blocks protein synthesis by which method?
Attaching to the 50S subunit of the ribosome clindamycin also does this
Which of the following are synthetic antimicrobial drugs? Azoles Quinolones Streptomycin Quinines Penicillins
Azoles Quinolones Quinines
Polymyxins are derived from a species of which of the following?
Bacillus
Which of the following is a bacterial cell wall inhibitor found in over-the-counter antibacterial ointments? Ciprofloxacin Tetracycline Amoxicillin Bacitracin Streptomycin
Bacitracin
Neosporin is an antibiotic ointment composed of which three antibiotics? Streptomycin Clindamycin Bacitracin Neomycin Polymixin
Bacitracin Neomycin Polymixin
Which of the following semisynthetic penicillins are useful in treating infections caused by penicillinase-producing bacteria? Nafcillin Penicillin G Streptomycin Piperacillin Cloxacillin Erythromycin
Nafcillin Cloxacillin
Which term describes the process of some microbes dying while others live in the presence of antimicrobial agents?
Natural selection
Which of the following occurs when antibiotics interact in ways that enhance or magnify each other?
Synergism
What is the term for an antimicrobial drug that is chemically synthesized in the laboratory?
Synthetic
A semisynthetic antibiotic is a drug which is chemically modified in the laboratory after being isolated from natural sources. T/F
T
One of the ideal characteristics of a good antimicrobial drug is that it complements or assists the immune response of the host. T/F
T
Resistance factor plasmids are transferred to other bacterial cells during transformation, transduction, and conjugation. T/F
T
Species of Bacillus produce bacitracin and the polymyxins. T/F
T
True or false: Damage to the bacterial cell membrane can disrupt metabolism or lyse the cell. True false question.
T
The major side effects of quinolones involve which system?
Nervous
___________ ________ serves as the parent compound for all "-cillin" drugs.
Penicillin G
Which of the following is a natural fermentation product of Penicillin chrysogenum?
Penicillin G
Resistance to this drug typically results from a plasmid-encoded protein that pumps that drug out of the cell.
Tetracyclines Penicillins Reason: The effects of penicillin occurs external to cells so a "pump" is not required.
Which bacteria are the most susceptible to antibiotics that target the cell wall?
young, growing
Molds
Penicillium and Cephalosporium
Sulfisoxazole is not the preferred drug for treating which of the following diseases?
Tuberculosis and leprosy
Fosfomycin trimethamine is frequently used to treat which of the following?
UTI
Trimethoprim and sulfamethoxazole are used in combination to treat which of the following conditions? Urinary tract infections Otitis media Heart valve infections Tuberculosis Pneumocystis pneumonia Staphylococcal infections
Urinary tract infections Otitis media Pneumocystis pneumonia
Aztreonam is used to control which of the following conditions? Gastroenteritis Urinary tract infections Tuberculosis Pneumonia Septicemia
Urinary tract infections Pneumonia Septicemia
Sulfisoxazole is the best antimicrobial for treating which of the following diseases?
Urinary tract infections Shigellosis
The cell walls of most bacteria are composed primarily of which of the following?
Peptidoglycan
Which of the following is not a characteristic of an ideal antimicrobial drug?
Replaces host's own defenses
Which of the following would not help limit drug resistance of microorganisms? Multiple choice question. Research should focus on longer course antibiotics that are more effective at lower doses. Patients must comply with physicians guidelines when taking antibiotics. Physicians should prescribe antibiotics carefully by choosing narrow-spectrum agents when possible. Research should focus on developing shorter term, higher-dose antibiotics.
Research should focus on longer course antibiotics that are more effective at lower doses.
Two major problems for treatment with penicillin are that some patients experience which of the following? Intestinal bleeding Drug toxicity Aplastic anemia Resistant strains of pathogens Allergic responses
Resistant strains of pathogens Allergic responses
Protein synthesis inhibiting drugs affect the activity of which of the following?
Ribosomes
Which of the following drugs inhibits transcription?
Rifampin
_________ is the recommended antibiotic for prophylaxis in Neisseria meningitidis.
Rifampin
Identify the major side effects of quinolones. Renal failure Risk of aortic aneurysms Damage to tendons Seizures Liver damage Stomach ulcers Allergic reaction
Risk of aortic aneurysms Damage to tendons Seizures
Which of the following ointments is prescribed for treatment of eye infections?
Silver sulfadiazine
Antibiotics are derived from all the following except Cephalosporium. Staphylococcus. Streptomyces. Bacillus. Penicillium
Staphylococcus
A great number of antibiotics are derived from which of the following bacterial genera?
Streptomyces Bacillus
Which of the following genera produce aminoglycosides?
Streptomyces Micromonospora
Which of the following aminoglycosides is still the antibiotic of choice for treating bubonic plague and tularemia?
Streptomycin
Which of the following are antimicrobials that block the folic acid pathway in bacteria?
Sulfonamides
Resistance to which of the following drugs develops when microbes deviate from the usual pathway that leads to the production of folic acid? Erythromycin Sulfonamides Cephalosporins Trimethoprim Aminoglycosides
Sulfonamides Trimethoprim
Which of the following interfere with folate metabolism? Amphotericin B Sulfonamides Gentamicin Chloramphenicol Trimethoprim
Sulfonamides Trimethoprim
Ampicillin, amoxicillin, mezlocillin, and penicillin G all have -an expanded spectrum of activity. -All of the choices are correct. -a semisynthetic nature. -resistance to the action of penicillinase. -a beta-lactam ring.
a beta-lactam ring.
Why are antibiotics that attack the cell wall considered bactericidal?
a weakened cell wall leads to cell lysis
Patients taking penicillin may experience ________ reactions.
allergic
Antibiotics are made primarily by aerobic spore-forming ________ and __________.
bacteria fungi
Most antimicrobial drugs are derived from which two bacterial and which two fungal genera?
bacteria: bacillus, streptomyces fungal: penicillium, cephalosporium
Amoxicillin, a semisynthetic variant is effective at crossing the outer membrane of gram negative bacteria. This feature makes amoxicillin a _______ anitibiotic
broad spectrum
Tetracycline is an example of which type of drug?
broad spectrum
Antimicrobics effective against a wide variety of microbial types are termed
broad-spectrum drugs.
The production of beta-lactamases is responsible for which of the following?
drug inactivation Reason: The "ase" ending indicates an enzyme which in this case, inactivates the beta-lactam ring of penicillin.
The tolerance of an antimicrobial agent at a level which would normally be inhibitory is called which of the following?
drug resistance
One mechanism by which microbes can become resistant to a drug is to produce a(n) _______ that alters the structure of the drug.
enzyme
The macrolide, __________, is a useful substitute for dealing with penicillin-resistant Streptococci
erythromycin
The antimicrobial silver sulfadiazine is prescribed for the treatment of which of the following? Eye infections Kidney infections Ringworm Pneumocystis pneumonia Athletes foot Burns
eye infections burns
Which antimicrobic does not inhibit with protein synthesis fluoroquinolones tetracylines macrolides chloramphenicol aminoglycosides
fluoroquinolones
Resistance to sulfonamides and trimethoprim develops when microbes use an alternative pathway for __________ acid synthesis.
folic
Urinary tract infections caused by enteric bacteria
fosfomycin
Bacteria
gentamycin bacitracin streptomycin tetracycline
The primary target of fluoroquinolones in Gram-negative bacteria is the enzyme, DNA _________
gyrase
The goal of antimicrobial chemotherapy is to ______ the infective agent without harming the _________.
kill host
Sulfones are used to treat which of the following conditions?
leprosy
_________ analogs are structurally similar to the natural substrate and compete with it for the active site on the enzyme.
metabolic
Which of the following is not a primary site for action of antimicrobial drugs in bacteria?
mitochondria
Drug resistance occurs with spontaneous ________ or gene transfer from another species.
mutations
Isoniazid works by interfering with the synthesis of __________ acid.
mycolic
An antibiotic that is only effective against a limited array of different microbes is called a(n) ___________ spectrum antibiotic.
narrow
Bacitracin is an antibiotic with which spectra of activity?
narrow
Antimicrobics effective against only gram-positive bacteria would be termed
narrow-spectrum drugs
The outer membrane of some Gram- _______ bacteria act as natural barriers to some drugs.
negative
Polymyxins work well on Gram-________ cells and daptomycin shows selectivity for Gram-_________ cells.
negative positive
Rifampin disrupts the formation of which macromolecules? Nucleic acids Proteins Lipids Carbohydrates
nucleic acids
The ________ ________ of the cell wall of certain gram-negative bacteria is a natural blockade against some penicillin derivatives.
outer membrane
Cephalosporins are given orally, when poorly absorbed from the intestine they must be administered _________________.
parenterally (injection into the body, could be in the muscle)
Which of the following is an example of drug that blocks bacterial cell wall synthesis and exhibits excellent selective toxicity?
penicillin
The cephalosporins closely resemble which group of antibiotics in terms of structure and function? Penicillins Aminoglycosides Tetracyclines Macrolides Sulfonamides
penicillins
The mode of action of chloramphenicol is to block the formation of which of the following bonds?
peptide cuz it prohibits the 50S ribosome, which helps create protein that has peptide bonds
Polymyxins interact with which of the following membrane component(s), causing leakage of cellular contents?
phospholipids
Fosfomycin trimethamine is a _________ acid agent against enteric bacteria.
phosphoric
A resistance factor is a ________ that confers drug resistance and is often shared among bacteria by conjugation.
plasmid
Trimethoprim is used in combination with sulfamethoxazole to treat caused by Pneumocystis jiroveci.
pneumonia UTI Otitis media
Which is the only antibiotic that targets bacterial cell membranes though it can only be used externally due to kidney toxicity?
polymyxin
Daptomycin is a lipopeptide directed mainly against Gram-_________ bacteria.
positive
Penicillin targets the bacterial cell wall making it effective against gram ________ organisms
positive
A patient who has recently undergone a total joint replacement surgery is given antibiotics prior to dental procedures.
prophylaxis
The use of a drug to prevent imminent infection of a person at risk is called which of the following?
prophylaxis
Resistance to tetracycline typically results from plasmid-encoded proteins that ____________ that drug out of the cell.
pump
Drug ________ of microbes to specific drugs can increase as a result of genetic based changes in the target site (receptor) that the drug binds to.
resistance
Which is descriptive of L-forms?
resistant to penicillin This is because penicillin blocks the formation of the cell wall
Which cell wall inhibitor is typically used to treat staphylococcal infections that are resistant to penicillin and methicillin? Amoxicillin Streptomycin Erythromycin Vancomycin
vancomycin
Which of the following diseases is controlled by clindamycin? -Intestinal infections caused by anaerobes -Drug-resistant tuberculosis -Drug-resistant staphylococcal infections -Acne
-Intestinal infections caused by anaerobes -Drug-resistant staphylococcal infections -Acne
Which of the following are strategies that can help limit drug resistance of microorganisms? -Research should focus on longer course antibiotics that are more effective at lower doses -Physicians should prescribe antibiotics carefully by choosing narrow-spectrum agents when possible -Research should focus on developing shorter term, higher-dose antibiotics -Patients must comply with physicians guidelines when taking antibiotics -Physicians should prescribe antibiotics to combat illness immediately
-Physicians should prescribe antibiotics carefully by choosing narrow-spectrum agents when possible -Research should focus on developing shorter term, higher-dose antibiotics -Patients must comply with physicians guidelines when taking antibiotics
Please select the five major mechanisms of antimicrobial resistance.
-enzymatic inactivation of the antibiotic -antibiotic efflux pumps the antibiotic out of the cell -altered target site, such that the antibiotic can no loner bind to the target -microbe uses an alternative pathways to circumvent the blocked pathway -decreased permeability to the antibiotic
Please select the five primary modes of actions of antimicrobial drugs.
-inhibition of cell wall synthesis -disruption of cell membrane structure or function -inhibition of protein synthesis -blocking key metabolic pathways -disruption of structure or function of nucleic acids (DNA/RNA)
How does a bacterial cell acquire resistance genes?
-plasmid genes -conjugation from other bacteria -chromosomal genes from other bacteria -transduction via viruses
Please select the strategies that can be used to reduce the level of antimicrobial drug resistance. -prescribing antibiotics ONLY for accurately diagnosed bacterial infections prescribing antibiotics ONLY for accurately diagnosed bacterial infections -instructing patients to discontinue taking the antibiotic as soon as they are symptom free -using antibiotics to treat colds and the flu restricting use of newly-developed antibiotics to those situations when the etiologic agent has been shown to be resistant to more traditional antibiotics -limiting the use of antibiotics in animal feed
-prescribing antibiotics ONLY for accurately diagnosed bacterial infections -restricting use of newly-developed antibiotics to those situations when the etiologic agent has been shown to be resistant to more traditional antibiotics -limiting the use of antibiotics in animal feed
Erythromycin and clindamycin resistance is associated with an alteration of the drugs target on the organism's __________.
50S ribosomal subunit
Approximately what percent of infections involve biofilms?
60%
This % of infections involves biofilms, complex communities of microorganisms growing within an extracellular matrix.
60%
These antibiotics are amino sugars linked to 6-carbon rings.
Aminoglycosides
Which of the following is the consequence of exposure of a bacterium to an antibiotic that inhibits cell wall synthesis?
Cell lysis
Which of the following are primary sites for action of antimicrobial drugs in bacteria? Golgi apparatus (bodies) Cell wall Ribosomes Nucleic acids Mitochondria Cell membrane
Cell wall Ribosomes Nucleic acids Cell membrane
Cell wall inhibitors like penicillins and cephalosporins interfere with enzymes responsible for which of the following?
Cell wall construction
Which of the following antibiotics contain the beta-lactam ring? Cephalosporins Tetracyclines Penicillins Quinolones
Cephalosporins Penicillins
Which of the following antibiotics attaches to the 50S subunit of the ribosome in a way that prevents the formation of peptide bonds and blocks protein synthesis?
Chloramphenicol
Which of the following antibiotics attaches to the 50S subunit of the ribosome in a way that prevents the formation of peptide bonds and blocks protein synthesis? Streptomycin Penicillin Gentamicin Chloramphenicol
Chloramphenicol
Which of the following broad-spectrum antibiotics has limited use because it can lead to aplastic anemia?
Chloramphenicol
Which of the following is limited to treating rickettsial and chlamydial infections when an alternative therapy is unavailable?
Chloramphenicol
_______ is a broad-spectrum antibiotic that blocks peptide bond formation during protein synthesis and is solely synthetic.
Chloramphenicol
Which is mismatched? Fleming-penicillin Florey and Chain-penicillin Ehrlich-tetracycline Domagk-sulfonamide
Ehrlich-tetracycline
Synercid is effective against members of which genera? Enterococcus Pseudomonas Streptococcus Staphylococcus Enterobacter Proteus
Enterococcus Streptococcus Staphylococcus
Microbes can inactivate drugs by producing which of the following that change the structure of the drug to a nontoxic form?
Enzymes
Which of these drugs is used to treat cases of tuberculosis?
Isoniazid
Polymyxin B and E are toxic to which organ?
Kidneys
What term is used to describe bacteria lacking cell walls?
L-forms
Rifampin figures most prominently in the treatment of which two of the following diseases? Leprosy Ulcers Lyme disease Tuberculosis MRSA
Leprosy Tuberculosis
This is a synthetic drug of the class oxazolidinones that inhibit protein synthesis. It is being used to control MRSA and VRE infections.
Linezolid
Linezolid is effective in the treatment against which of the following? HIV SARS MRSA VRE
MRSA VRE
Clarithromycin and azithromycin belong to which group of drugs?
Macrolides
Which of the following are characteristics of an ideal antimicrobial drug? Replaces host's own defenses Microbicidal Inexpensive Longevity Selective toxicity to infecting agent
Microbicidal Inexpensive Longevity Selective toxicity to infecting agent
Which of the following genera produce aminoglycosides? Neisseria Micromonospora Bacillus Streptomyces
Micromonospora Streptomyces
Which of the following diseases can be treated with tetracyclines such as doxycycline and minocycline? Bubonic plague Mycoplasma pneumonia Cholera Tuberculosis Rocky Mountain spotted fever
Mycoplasma pneumonia Cholera Rocky Mountain spotted fever
Which of the following are quinolones?
Norfloxacin Ciprofloxacin
Which of the following are antifungal antibiotics? Tetracyclines Nystatin Vancomycin Amphotericin B Streptomycin
Nystatin Amphotericin B
Antimicrobial drugs that damage cell membrane function usually do so by creating leaks in the membrane that disrupt which of the following? Communication with other cells Osmotic tolerance Genetic expression Cell metabolism
Osmotic tolerance Cell metabolism
Trimethoprim and sulfamethoxazole are used in combination to treat which of the following conditions? Heart valve infections Otitis media Urinary tract infections Staphylococcal infections Pneumocystis pneumonia Tuberculosis
Otitis media Urinary tract infections Pneumocystis pneumonia
Resistance to aminoglycosides can result from changes in cell permeability caused by mutations in proteins in which of the following? Folic acid pathway Outer membrane Krebs cycle Ribosome Transport system
Outer membrane Transport system
Sulfonamides compete with __________ for the active site of the enzyme that synthesizes the folic acid precursor.
PABA
Aztreonam is often used by patients who are allergic to which antibiotic? Penicillin Erythromycin Tetracycline Streptomycin Chloramphenicol
Penicillin
Tetracyclines inhibit which of the following?
Protein synthesis (Tetracyclines bind to the small subunit of the ribosome, thus interfering with protein synthesis.)
The ending -floxacin is used for which category of drugs?
Quinolones
Biofilms are best known to do which of the following?
Reduce drug efficacy
Identify the mode of action of the polyene antifungal antibiotics. They bind to the DNA and prevent transcription. They form complexes with fungal sterols in their cell membranes causing seepage of small ions. They attach to the 70S ribosome inhibiting protein synthesis. They cause a breakage in the peptidoglycan.
They form complexes with fungal sterols in their cell membranes causing seepage of small ions.
Which of the cephalosporins is effective for treating infections by enteric bacteria that produce beta-lactamases? First-generation Third-generation Fourth-generation Second-generation
Third-generation
Which tetracycline is being used in hospitals to treat MRSA infections?
Tigecycline a new strain of tetracycline
What is the overall goal of antimicrobial chemotherapy?
To destroy the infective agent without harming the patient To provide the patient with immunity against future infections by the microbe Reason: The goal is to kill the microbe with the drug To boost the patients immune response in order to destroy the infective agent Reason: The goal is to kill the microbe with the drug
Which of the following inhibits folic acid synthesis?
Trimethoprim
True or false: Microorganisms that produce antibiotics in their natural habitat may have a selective advantage over neighboring microbes.
True
True or false: Tetracyclines can be used to treat infections caused by mycoplasmas.
True Reason: These are broad-spectrum antibiotics that can be used to treat a variety of bacteria (gram - &+, rods, cocci, aerobic, anaerobic, mycoplasmas, rickettsias, spirochetes) including mycoplasmas. doxycycline and minocycline are tetracyclines
Which of the following is an inclusive term for any drug used to fight infection, regardless of its causative agent?
antimicrobial
Sulfonamides
are metabolic analogs of PABA and block folic acid synthesis.
Multi-drug-resistant tuberculosis
bedaquiline
Which "formation" is produced by some microbes which in turn makes them resistant to some antimicrobial compounds and the shear force of moving liquids?
biofilm
Bacteria that form ________ are difficult to control because the buildup of cells makes it difficult to for the antibiotic to reach a majority of the cells.
biofilms
An antibiotic that is effective against a wide variety of microbial types is called a(n) ________ spectrum antibiotic.
broad
Which describes the spectrum of activity of the tetracyclines?
broad
Which describes the spectrum of the highly potent fluoroquinolones?
broad
Clindamycin is a _________ - spectrum antibiotic derived from ___________.
broad lincomycin
An antimicrobial drug that is effective against a very diverse array of bacteria is described as __________ spectrum, whereas a drug that is very selective for a just a few different types of bacteria is described as __________ spectrum.
broad narrow
What is the cellular target of daptomycin?
cell membrane function
Which of the following structures in bacteria protect the cell from lysis (rupture) in hypotonic environments?
cell wall
Organisms resistant to penicillins and ____________ often produce beta-lactamases that hydrolyze the beta-lactam ring structure of the antibiotic.
cephalosporins
The _______ are similar in structure to penicillins and interfere with cell wall synthesis.
cephalosporins
Which drug is any agent used in the treatment, relief, or prophylaxis of a disease?
chemotherapeutic
The drug that can cause aplastic anemia, and is used to treat typhoid fever and brain abscesses is
chloramphenicol.
A chemical that inhibits beta-lactamase enzymes is
clavulanic acid
The drug used against intestinal anaerobic bacteria, that can also alter normal microbiota causing antibiotic-associated colitis is _________
clindamycin.
The use of two or more drugs to treat one infection or disease is called __________ therapy.
combination
A patient infected with HIV usually takes several different anti-HIV medications, including a reverse transcriptase inhibitor, one or more protease inhibitors, and an integrase inhibitor.
combined therapy
Systemic infections caused by gram-positive bacteria
daptomycin
The broad-spectrum quinolones inhibit which of the following?
helicase
Which of the following are representative of the quinolone group of antimicrobials?
inhibit DNA gyrase and topoisomerase -interfere with DNA replication and transcription -includes norfloxacin and criprofloxacin
The property of an antimicrobial agent to be highly toxic against its target microbe while being far less toxic to the cells of the host organism is called _______ toxicity.
selective
The ability of an antibiotic to kill or inhibit the growth of microbes without simultaneously damaging host tissues is considered _____ ______.
selective toxicity
The most common approach to drug production is the _________ method, which combines both natural and synthetic methods.
semisynthetic
Which of the following is an antimicrobial drug isolated from natural sources and then chemically modified in the laboratory?
semisynthetic
Erythromycin, the first macrolide antibiotic, was discovered in 1949 when scientists at Eli Lilly isolated the natural product from the culture broth of the soil-dwelling fungus Saccharopolyspora erythrea. Chemical modifications in its structure were needed due to being unstable under acidic conditions, giving rise to side effects such as stomach pain. Select which category of antimicrobial drugs erythromycin belongs to?
semisynthetic drugs
What is a major side effect of tetracyclines
staining of teeth
Alexander Fleming discovered the compound penicillin in 1928 after his observations on the antibacterial effects of the mold Penicillium chrysogenum on which of the following microbes?
staphylococcus aureus
Sulfonamides, ___________ or drugs, are synthetic antimicrobial drugs that interfere with essential metabolic processes of bacteria and some fungi.
sulfa
Broad-spectrum drugs that disrupt the body's normal microbiota often cause ________
superinfections.
Endocarditis and surgical infections caused by Staphylococcus and Enterococcus species
synercid
In a recent study, the drug sanguinarine demonstrated a strong activity against gram-positive and gram-negative bacteria, while streptomycin was active against gram-negative strains, and EDTA had only bacteriostatic activity. Interestingly, the three-drug combination strongly reduced almost all the strains studied, as well as the effective doses needed. Based on these results, what would be the name of this type of drug strategy?
synergy
Trimethoprim and sulfamethoxazole are often used together because they inhibit two successive steps in the folate biosynthetic pathway and this inhibition is greater than when either drug is used alone.
synergy
Respiratory tract infections caused by macrolide-resistant bacteria
telithromycin (ketolide)
Please select all of the antimicrobial drugs that block protein synthesis.
tetracycline chloramphenicol amikacin erythromycin
The staining of teeth is one side effect of the antibiotic group known as the
tetracyclines
All of the following pertain to cephalosporins except -they are synthetic drugs. -they have a beta-lactam ring. -many administered by injection not orally. -greater resistance to beta-lactamases. -newer generations have activity against gram negatives.
they are synthetic drugs
Synercid binds to ribosomes inhibiting the process of _______
translation
The antibiotic ____________ is non-beta-lactam cell wall inhibitor that is usually restricted to the most serious and life-threatening conditions.
vancomycin
