Chapter 20: Antimicrobial Medications
Chemicals used in the therapy of infectious diseases are called
antimicrobial medications
Chemotherapeutic agents that are used to treat microbial infections can be more specifically called
antimicrobial medications
The Kirby-Bauer disc diffusion test is routinely used to determine ______.
the susceptibility of a given bacterial strain to an assortment of antimicrobial drugs
What type of penicillin? Narrow-spectrum antibiotics produced by Penicillium chrysogenum.
Natural penicillins
Antibiotics that target which of the following would be effective against viruses? Folic acid biosynthesis Membrane synthesis Peptidoglycan synthesis 70S ribosome function None of the choices is correct.
None of the choices is correct
What is targeted by antiviral medications such as acyclovir, ribavirin, and AZT?
Nucleic acid synthesis
A patient has a urinary tract infection. Why is this a good example of an infection that can usually be treated well with bacteriostatic antimicrobials, e.g., sulfa drugs?
Once bacterial growth is stopped, urination can usually be counted on to flush the pathogens.
To treat a case where the patient's defenses are unlikely to clear an infection, which would be the more appropriate choice of an antimicrobial drug, one that is bactericidal or bacteriostatic?
One that is bactericidal
What protein synthesis medication is bacteriostatic against a variety of gram-positive bacteria; binds to the 50S ribosomal subunit, interfering with the initiation of protein synthesis; a relatively new class that is useful for treating infections caused by bacteria that are resistant to other options
Oxazolidinones
Which of the following statements about antibiotic resistance is FALSE? -Combination therapy reduces the likelihood of a bacterium developing resistance. -Patients should stop taking antibiotics as soon as they feel better, to avoid developing resistance. -Genes for antibiotic resistance are frequently found on plasmids. -Efflux pumps allow some bacteria to eject antibiotics. -A single mutation may be sufficient for a bacterium to develop resistance.
Patients should stop taking antibiotics as soon as they feel better, to avoid developing resistance.
What antibacterial medications inhibit folate biosynthesis?
Sulfonamides and trimethoprim
What antimicrobial medications bind to the 30S subunit of the bacterial 70S ribosome?
Tetracyclines Glycylcyclines Aminoglycosides
What protein synthesis medication is bacteriostatic against some gram-positive and gram-negative bacteria; bind to the 30S ribosomal subunit, blocking the attachment of tRNA?
Tetracyclines and glycylcyclines
When treating an infection with a combination of antimicrobials, why might a bacteriostatic drug be antagonistic when used with a bactericidal drug? -The two drugs will bind to each other rather than to the drug targets in the bacteria, rendering both useless. -The bactericidal drug relies on actively dividing cells to work; the bacteriostatic drug prevents cells from actively dividing. -The bacteriostatic drug will interfere with the excretion of the bactericidal drug, causing it to build up to potentially toxic levels. -The bacteriostatic drug will break down the bactericidal drug, rendering it useless. -The bacteriostatic drug will interact with the bactericidal drug; the combination can be toxic to the host.
The bactericidal drug relies on actively dividing cells to work; the bacteriostatic drug prevents cells from actively dividing.
After testing to determine the susceptibility of an organism to various drugs, what are important considerations when choosing a drug to use? -The drug should kill as many species of bacteria as possible. -The drug should act against the pathogen. -The drug should act against as few other bacteria as possible. -The drug should have a low therapeutic index.
The drug should act against the pathogen. The drug should act against as few other bacteria as possible.
True or False: Antiviral medications that interfere with genome integration will be useful against all animal viruses.
False
True or false: Susceptibility of a pathogen to a specific antimicrobial drug is almost always predictable.
False
True or false: Most antibacterial medications interfere with metabolic pathways.
False (relatively few antibacterial medications interfere with metabolic pathways. There are many more with other targets such as cell wall synthesis, ribosomes, and nucleic acid synthesis.)
What medication that inhibits nucleic acid synthesis is bactericidal against a wide variety of gram-positive and gram-negative bacteria; inhibit topoisomerases?
Fluoroquinolones
What antibacterial medications inhibit nucleic acid synthesis?
Fluoroquinolones (ciprofloxacin, moxifloxacin); rifamycins; metronidazole
Which of the following antimicrobials inhibit nucleic acid synthesis? -Fluoroquinolones, rifamycins, and metronidazole -β-lactams, chloramphenicol and tetracyclines
Fluoroquinolones, rifamycins, and metronidazole (β-lactams interfere with the synthesis of peptidoglycan cell walls and tetracylines and chloramphenicol interfere with the function of 70S ribosomes)
Changing an antibiotic so that it could pass through a porin protein would likely cause -Gram-negative cells to become sensitive to that medication. -Gram-negative cells to become resistant to that medication. -Gram-positive cells to become sensitive to that medication. -Gram-positive cells to become resistant to that medication. -viruses to become sensitive to that medication.
Gram-negative cells to become sensitive to that medication
What enzymes are inhibited by β-lactam antibiotics? Peptidoglycan synthases Penicillin-cleaving proteins β-lactamases Penicillin-binding proteins β-lactams
Penicillin-binding proteins
What type of penicillin? Developed in response to resistant Staphylococcus aureus.
Penicillinase-resistant penicillins
What family of Beta-lactam antibacterial medications has different groups that vary in their spectrum of activity and their susceptibility to beta-lactamase
Penicillins
What type of penicillin? Combination of agents, resistant to enzymatic destruction.
Penicillins + β-lactamase inhibitor
In 1928, Alexander Fleming noticed that colonies of Staphylococcus aureus growing near a contaminating mold looked as if they were dissolving. He identified the mold, which was producing the first discovered antibiotic, as a species of
Penicillium
Which of the following is the target of methicillin? Peptidoglycan synthesis 70S ribosomes 80S ribosomes Cytoplasmic membrane function Folic acid synthesis
Peptidoglycan synthesis
What protein synthesis medication is bacteriostatic against a variety of gram-positive bacteria; binds to the 50S ribosomal subunit, preventing peptide bonds from being formed; the only derivative currently approved for humans is for topical use only
Pleuromutilins
What medication that inhibits cell membrane integrity is bactericidal against gram-negative bacteria by damaging cell membranes; toxicity limits their use
Polymyxins
What medication that inhibits nucleic acid synthesis is bactericidal against gram-positive and some gram-negative bacteria; binds RNA polymerase, blocking the initiation of RNA synthesis?
Rifamycins
All of the following about the Kirby-Bauer test are true EXCEPT -the area in which no bacteria grow is called the zone of inhibition. -the zone size reflects in part an organism's sensitivity to a drug. -a drug concentration gradient develops around each disc. -each disc contains a known amount of antibiotic. -a large zone of inhibition indicates extreme sensitivity to a drug.
a large zone of inhibition indicates extreme sensitivity to a drug.
A broad-spectrum antimicrobial is most likely effective against ______. -a wide range of both Gram-positive and Gram-negative bacteria -only Gram-negatives but not Gram-positives -bacteria that are growing at high densities, rather than when just a few are present -a certain type of bacteria, for example, just those involved in respiratory tract infections -only Gram-positives but not Gram-negatives
a wide range of both Gram-positive and Gram-negative bacteria
When antimicrobials are used in combination, and their interaction is neither antagonistic nor synergistic, the combination is said to be
additive
What medication that inhibits folate biosynthesis is bacteriostatic against a variety of gram-positive and gram-negative bacteria; structurally similar to para-aminobenzoic acid (PABA) and therefore inhibit the enzyme for which PABA is a substrate?
Sulfonamides
Match each antibacterial medication with its appropriate mechanism of action. vancomycin fluoroquinolones daptomycin trimethoprim aminoglycosides
- Vancomycin - cell wall (peptidoglycan) synthesis - Fluroquinolones - Nucleic acid synthesis - Daptomycin - Cell membrane integrity - Trimethoprim - Metabolic pathways (folate biosynthesis) - Aminoglycosides - Protein synthesis
What does each class of antibacterial medication target? β-lactam drugs rifamycins polymyxin B sulfonamides tetracyclines
- β-lactam drugs - Cell wall (peptidoglycan) synthesis - Rifamycins - Nucleic acid synthesis - Polymyxin B - Cell membrane integrity - Sulfonamides -Metabolic pathways (folate biosynthesis) - Tetracyclines - Protein synthesis
Which of the following statements about antibiotics is FALSE? -Rifampicin binds bacterial RNA polymerase and inhibits initiation of transcription. -Streptomycin binds the small subunit of the 70S ribosome. -Chloramphenicol inhibits peptidyl transferase of the 70S ribosome. -Tetracycline blocks the binding of tRNA to the 70S ribosome. -Antibiotics prevent capsid formation during viral replication.
-Antibiotics prevent capsid formation during viral replication
Match the antifungal medications listed with the correct cellular target: -Griseofulvin -Echinocandins -Polyenes, Azoles, Allylamines -Flucytosine -Cell division -Plasma membrane synthesis and function -Nucleic acid synthesis -Cell wall synthesis
-Cell division: Griseofulvin -Plasma membrane synthesis and function: Polyenes, Azoles, Allylamines -Nucleic acid synthesis: Flucytosine -Cell wall synthesis: Echinocandins
Malarone is a synergistic combination of atovaquone and proguanil hydrochloride that interferes with mitochondrial activity. Given this information, which of the following statements are TRUE? -Given its mechanism of action, malarone would be effective in preventing viral entry into host cells -Given its mechanism of action, malarone would be effective against protozoa -The therapeutic effect of malarone is poorer than that of either atovaquone or proguanil hydrochloride -The therapeutic effect of malarone is better than that of either atovaquone or proguanil hydrochloride
-Given its mechanism of action, malarone would be effective against protozoa -The therapeutic effect of malarone is better than that of either atovaquone or proguanil hydro
Please select the four major mechanisms of antimicrobial resistance. Increase in elimination of a medication (uses special pumps to remove the medication from the cell). Utilizing the antimicrobial medication as an energy source. Decreased uptake of the medications. Altered target site, such that the antibiotic can no longer bind to the target. Producing drug-inactivating enzyme(s).
-Increase in elimination of a medication (uses special pumps to remove the medication from the cell). -Decreased uptake of the medications. -Altered target site, such that the antibiotic can no longer bind to the target. -Producing drug-inactivating enzyme(s).
Few medications are effective against Mycobacterium tuberculosis. Please check all the statements explaining why this situation exists. M. tuberculosis has a slow generation time. Mycobacteria do not have a peptidoglycan cell wall. The cell wall of M. tuberculosis prevents entry of medications. M. tuberculosis has developed resistance to many medications. M. tuberculosis undergoes frequent antigenic changes.
-M. tuberculosis has a slow generation time. -The cell wall of M. tuberculosis prevents entry of medications. -M. tuberculosis has developed resistance to many medications.
Please select all the different mechanisms by which antiviral medications work. Preventing viral cell wall synthesis Preventing entry of the virus into the host cell Directly disrupting viral capsids Blocking viral nucleic acid synthesis Preventing the maturation of viral particles Directly disrupting viral envelopes
-Preventing entry of the virus into the host cell -Blocking viral nucleic acid synthesis -Preventing the maturation of viral particles
All β-lactam antibiotics have the same target. Select two reasons why they vary in their spectrum of activity. -Some cannot pass through the outer membrane of Gram-negative bacteria. -Some bacteria have 70S ribosomes while others have 80S ribosomes. -Some bacteria have single-stranded DNA and others have double-stranded DNA. -Different groups of bacteria have different penicillin-binding proteins. -Some β-lactam antibiotics can only target actively dividing cells.
-Some cannot pass through the outer membrane of Gram-negative bacteria. -Different groups of bacteria have different penicillin-binding proteins.
Select the reasons that isoniazid, ethambutol and pyrazinamide are used as first-line drugs in treating tuberculosis -They are the most effective in targeting M. tuberculosis. -They are less toxic to the person than second-line drugs. -They target the lipopolysaccharide layer of M. tuberculosis -They are less effective but also less toxic than second-line drugs. -They interfere with processes unique to M. tuberculosis.
-They are the most effective in targeting M. tuberculosis. -They are less toxic to the person than second-line drugs. -They interfere with processes unique to M. tuberculosis.
Select the TRUE statements regarding antibiotics that target the cell wall. -β-lactam antibiotics such as amoxicillin have a high therapeutic index. -β-lactam antibiotics inhibit enzymes called penicillin-binding proteins. -Vancomycin is inactivated by extended-spectrum β-lactamases. -Carbapenems are effective only against Gram-negative bacteria. -Carbapenemases may inactivate carbapenems, penicillins, cephalosporins, and monobactams.
-β-lactam antibiotics such as amoxicillin have a high therapeutic index. -β-lactam antibiotics inhibit enzymes called penicillin-binding proteins. -Carbapenemases may inactivate carbapenems, penicillins, cephalosporins, and monobactams.
What protein synthesis medication is bactericidal against aerobic and facultative bacteria, binds to the 30S ribosomal subunit blocking the initiation of translation and causing the misreading of mRNA, toxicity limits the use?
Aminoglycosides
What antibacterial medications inhibit protein synthesis?
Aminoglycosides (streptomycin, gentamicin, tobramycin, neomycin); tetracyclines and glyccylcyclines; macrolides (erythromycinm clarithromycin, azithromycin); chloramphenicol; lincosamides (lincomycin, clindamycin); oxazolidinones (linezolid); pleuromutilins (Reptapamulin); and streptogramins (quinupristin)
Please choose the statement that correctly explains how an antibiotic that inhibits protein synthesis can be selective. -Eukaryotic cells inactivate these antibiotics. -Antibiotics bind to the 70S bacterial ribosomes but not to the 80S eukaryotic ribosomes. -Antibiotics prevent the synthesis of bacterial tRNAs but not eukaryotic tRNAs. -Antibiotics prevent the synthesis of bacterial mRNAs but not eukaryotic mRNAs. -Eukaryotic cells are impermeable to these antibiotics so the antibiotics can't enter them.
Antibiotics bind to the 70S bacterial ribosomes but not to the 80S eukaryotic ribosomes.
This term is used to describe the molecular method by which a compound might kill or inhibit a microbe.
Antimicrobial actioin
Explain how drug resistance develops in bacteria and ultimately limits the usefulness of all known antimicrobials. -Antimicrobials kill or inhibit sensitive organisms, providing a selective advantage to resistant strains; these strains spread in the population. -Microbes develop resistance in response to exposure to antimicrobials in order to survive; they then do better than those that do not. -Antimicrobials create resistant strains of bacteria that grow much better than susceptible strains and come to dominate the population. -Antimicrobials cause microbes to mutate their DNA to develop resistance; this advantage allows them to flourish.
Antimicrobials kill or inhibit sensitive organisms, providing a selective advantage to resistant strains; these strains spread in the population.
Please choose the class of antimicrobials that would have the most selective toxicity. -Antimicrobials that interfere with cell membrane structure and function. -Antimicrobials that interfere with nucleic acid structure and function. -Antimicrobials that inhibit cell wall synthesis. -Antimicrobials that inhibit protein synthesis. -All of the choices are correct.
Antimicrobials that inhibit cell wall synthesis.
How does Glycopeptide antibiotics interfere with peptidoglycan synthesis?
Binding to the amnio acid side chain of NAM molecules, bloocking formation of cross-links between adjacent glycan chains; used to treat serious infections caused by Gram-positive bacteria that are resistant to most other options (bactericidal against Gram-positive bacteria)
Antimicrobials that are effective against a wide range of bacteria are known as
Broad-spectrum antimicrobials
What type of penicillin? Active against penicillin-sensitive Gram-positive and many Gram-negative bacteria.
Broad-spectrum penicillins
A patient has meningococcal meningitis, an acute life-threatening disease caused by the bacterium Neisseria meningitidis. Which type of antibiotic would be the most appropriate to prescribe? -Narrow-spectrum, low therapeutic index -Narrow-spectrum, intermediate therapeutic index -Broad-spectrum, low therapeutic index -Broad-spectrum, high therapeutic index -Narrow-spectrum, high therapeutic index
Broad-spectrum, high therapeutic index
What family of Beta-lactam antibacterial medications have a broad spectrum of activity and are not destroyed by most beta-lactamases including extended-spectrum beta-lactamase, but are susceptible to carbapenemases?
Carbapenems
What family of Beta-lactam antibacterial medications have later generations that are generally more effective against Gram-negative bacteria and less susceptible to destruction by most beta-lactamase but susceptible to extended-spectrum beta-lactamase
Cephalosporins
What protein synthesis medication is bacteriostatic and broad-spectrum; binds to the 50S ribosomal subunit, preventing peptide bonds from being formed. Generally used only as a last resort for life-threatening infections
Chloramphenicol
What medication that inhibits cell membrane integrity is bactericidal against gram-positive bacteria by damaging the cytoplasmic membrane
Daptomycin
What antibacterial medications inhibit the cell membrane integrity?
Daptomycin and polynyxin
What medications are effective against Mycobacterium tuberculosis?
Ethambutol, Isoniazid, and pyrazinamide
What type of penicillin? Have greater activity against Pseudomonas aeruginosa.
Extended-spectrum penicillins
Most antibiotics come from species of bacteria and fungi that normally live _______.
In soils
How does beta-lactam antibiotics interfere with peptidoglycan synthesis
Inhibiting enzymes call penicillin-binding proteins (PBPs) that help from cross-links between adjacent glycan chains
How is ethambutol effective against TB?
Inhibits the synthesis of a component of the mycobacterial cell wall
How is isoniazid effective against TB?
Inhibits the synthesis of mycolic acids (a major component of the mycobacterial cell wall)
How is pyrazinamide effective against TB?
Interferes with a process that mycobacterial cells use to restart stalled ribosomes
Antibacterials like daptomycin and polymyxin B essentially make holes in the bacterial membrane. Why, in terms of the function of the membrane, is this deadly to bacteria? -It makes the membranes no longer selectively permeable. -It prevents the membranes from allowing substances across. -It makes the membranes more selectively permeable. -It forces the membranes to maintain a gradient of concentrations on either side. -It decreases the permeability of the membranes.
It makes the membranes no longer selectively permeable.
What protein synthesis medication is bacteriostatic against a variety of gram-positive and gram-negative bacteria; binds to the 50S ribosomal subunit, preventing the continuation of protein synthesis
Lincosamides
What protein synthesis medication is bacteriostatic against many gram-positive bacteria as well as the most common causes of atypical pneumonia; bind to the 50S ribosomal subunit, preventing the continuation of protein synthesis?
Macrolides
What medication that inhibits nucleic acid synthesis is bactericidal against anaerobes; activated by anaerobic metabolism and then binds DNA, interfering with synthesis and causing damaging breaks?
Metronidazole
What Beta-lactam antibiotic is primarily active against members of the family Enterobacteriacae, not inactivated by most beta-lactamases but susceptible to extended-spectrum beta-lactamases and some carbapenemases
Monobactams
Medically useful antimicrobial drugs exhibit _________, meaning they cause greater harm to microbes than to the human host
Selective toxicity
This term is used to describe compounds that cause greater harm to microbes than to the human host.
Selective toxicity
A patient is diagnosed with "walking pneumonia," caused by the bacterium Mycoplasma pneumoniae. Why should this patient NOT be given penicillin? -Some bacteria, such as Mycoplasma species, are intrinsically resistant to penicillin. -Other less toxic β-lactam medications would be more effective. -Mycoplasma bacteria are allergic to penicillin. -Penicillin causes lysogenic phages to reactivate, so the bacteria would produce toxins. People with pneumonia are susceptible to antibiotic-associated colitis.
Some bacteria, such as Mycoplasma species, are intrinsically resistant to penicillin.
This term is used to describe the range of different microbes that a compound can kill or inhibit.
Spectrum of activity
A researcher develops a new medication that acts by inhibiting microtubule formation (involved in mitosis). For diseases caused by which of the following pathogens would this medication NOT be used? Giardia species Taenia solium Plasmodium species Staphylococcus aureus Ascaris species
Staphylococcus aureus
What protein synthesis medication is a synergistic combination of two medications that bind to two different sites on the 50S ribosomal subunit, inhibiting distinct steps of protein synthesis; individually each medication of bacteriostatic, but together they are bactericidal; effective against a variety of gram-positive bacteria, but generally reserved for strains that are resistant to other antimicrobials
Streptogramins
What antimicrobial medications bind to the 50S subunit of the bacterial 70S ribosome?
Streptogramins Chloramphenicol Oxazolidinones Lincosamides Macrolides
Which of the following species are the four major producers of antibiotics? Histoplasma (fungus) Streptococcus (bacterium) Mycobacterium (bacterium) Cephalosporium (fungus) Streptomyces (bacterium) Aspergillus (fungus) Bacillus (bacterium) Penicillium (fungus)
Streptomyces and Bacillum (bacteria) Penicillium and Cephalosporium (fungi)
Penicillin, discovered by Alexander Fleming, was tested for the first time on a police officer with a life-threatening Staphylococcus aureus infection. The police officer died. Why? -There wasn't enough purified penicillin available to cure him completely -Staphylococcus aureus lacks peptidoglycan and is thus intrinsically resistant to penicillin. -Penicillin is used to cure fungal infections and S. aureus is a bacterium. -Penicillin is only effective against a small number of viruses. -The police officer was resistant to the penicillin.
There wasn't enough purified penicillin available to cure him completely.
Compared to conventional methods, commercial modifications of antimicrobial susceptibility testing offer what advantages? -They are less labor-intensive. -They are more effective at testing for anaerobic microorganisms. -They can test for microbes that cannot be tested via the other methods. -The results can be obtained more quickly.
They are less labor-intensive. The results can be obtained more quickly.
Effective antimicrobial drugs would need to demonstrate selective toxicity. What does this mean? -They target certain types of bacteria and not others. -They work only under certain conditions. -They cause greater harm to microbes than to the human host. -They work on either Gram-positive bacteria or Gram-negative bacteria, but not both. -They are effective against only a certain type of microbe, for example, bacteria or fungi or protozoa.
They cause greater harm to microbes than to the human host
There are a few antibacterial medications that interfere with cell membrane integrity. How do they lead to bacterial cell death? They prevent the assembly of the phospholipid bilayer. They cause the cells to leak. They degrade proteins embedded in the cell membrane. They prevent the cell from synthesizing new lipid membrane. They cause the phospholipids to reverse their orientation so that the polar head groups orient inward and the lipid tails point outward.
They cause the cells to leak
What is a special consideration when giving antimicrobials to patients who have kidney or liver dysfunction? -They may excrete or metabolize drugs more slowly, so their dosages should be adjusted accordingly to avoid toxic levels. -They are more likely to get infections in these organs, so their dose of antimicrobials should be increased to prevent this. -No special considerations are needed; individuals with kidney or liver dysfunction can take antimicrobials normally. -Their bodies will eliminate the drugs more rapidly, so a higher dose will be needed to maintain the proper level in the body to be effective.
They may excrete or metabolize drugs more slowly, so their dosages should be adjusted accordingly to avoid toxic levels.
What best explains why the first-line drugs are generally given in combination of two or more to patients who have active tuberculosis, caused by Mycobacterium tuberculosis? To reduce the chance that resistant mutants will develop. The drugs are relatively ineffective on their own, but together their action is synergistic. Mycobacterium are so resistant to antibacterials that it takes targeting at least two different processes to kill them. This avoids the need to determine whether or not the bacteria are resistant to the drug being used.
To reduce the chance that resistant mutants will develop
What medication that inhibits folate biosynthesis is often used with a sulfonamide for synergistic effect (a combination called a co-trimoxazole); inhibits the enzyme that catalyzes a step following the one inhibited by the sulfonamides
Trimethoprim
True or false: Compared to conventional methods of antimicrobial susceptibility testing, commercial modifications are less labor-intensive.
True
True or false: An antimicrobial medication is a chemical used to treat an infectious disease.
True (Medications are used to treat disease, and antimicrobial medications are used to treat infectious diseases)
Antimicrobial medications (also referred to as antimicrobial drugs or simply antimicrobials) are best defined as ______.
chemicals that inhibit the growth of or kill microorganisms
A group of medications called the _________ drugs are preferred for use against species of Mycobacterium, because they are the most effective as well as the least toxic.
first time
Among the most useful antibacterial medications that interfere with metabolic pathways are the ______ biosynthesis inhibitors: sulfonamides and trimethoprim.
folate
How does bacitracin inhibit cell wall synthesis?
interferes with the transport of peptidoglycan precursors across the cytoplasmic membrane; common ingredient in non-prescription antibiotic ointments (bactericidal against Gram-positive bacteria)
Certain bacteria are inherently resistant to the effects of some antimicrobials. Inherent resistance is called
intrinsic (or innate) resistance
The minimum inhibitory concentration (MIC) is the ______.
lowest concentration of a specific antimicrobial drug needed to prevent the growth of a given bacterial strain in vitro
The lowest concentration of a specific antimicrobial drug needed to prevent the growth of a given bacterial strain in vitro is known as the
minimum inhibitory concentration
first antibiotic discovered in 1928 by Alexander Fleming
penicillin
When certain bacteria are said to have intrinsic (innate) resistance, this means they have ______.
some inherent property that makes them generally more resistant to the effect of some antimicrobials
What antibacterial medications inhibit cell wall synthesis?
β-Lactam Antibiotics (Penicillins, Cephalosporins, Carbapenems, Monobactams); Glycopeptide antibiotics (Vancomycin); Bacitracin