94 Questions
Which statement accurately distinguishes between antibiotics and antimicrobial drugs?
Antibiotics are produced by microbes and harm other microbes, while antimicrobial drugs can be synthetic and suppress microorganisms.
Which best describes narrow-spectrum antibiotics?
They are less preferred due to their limited activity.
What is one of the main challenges mentioned in the text regarding antimicrobials?
Organisms that do not respond to any available drugs.
How have modern antimicrobial agents impacted morbidity and mortality?
Reduced both morbidity and mortality from infections.
What sets broad-spectrum antibiotics apart from narrow-spectrum antibiotics?
Broad-spectrum antibiotics can target a wide variety of microbes.
Why is continued progress needed in antimicrobial therapy according to the text?
As a response to evolving microbial resistance and limitations posed by certain drugs.
What is the first rule of antimicrobial therapy?
Match the drug with the infecting organism
Which technique is described as the quickest, simplest, and most versatile for identifying microorganisms?
PCR test
When should positive identification of an infecting organism be established?
As soon as possible
What is the primary consideration when prescribing an antimicrobial drug according to the text?
Considering host defenses and infection site
What is the most common indication for using multiple antibiotics?
Initial therapy of severe infection with unknown etiology
In antimicrobial therapy, what does an additive response mean?
The effect of combination is equal to sum of individual effects
Why might treatment with more than one antibiotic be required for an infection?
When infectious microbes differ in drug susceptibility
What is a potentiative interaction in antimicrobial therapy?
When effect of combination is greater than sum of individual effects
Why should dosages be adjusted in antimicrobial therapy?
To produce drug concentrations greater than MIC for the infection
What new method can detect very low titers of bacteria and viruses according to the text?
PCR test or nucleic acid amplification test
What is the primary cause of the gradual increase in resistance in microbes?
Spontaneous mutations in the microbe's DNA
In the process of conjugation, what constitutes an R factor?
Two unique DNA segments: one for drug resistance mechanisms and one for DNA transfer
How do antibiotics create selection pressure favoring the growth of drug-resistant organisms?
By eliminating sensitive organisms
Which type of antibiotics are most effective in facilitating the emergence of drug-resistant organisms?
Broad-spectrum antibiotics
What is a superinfection as described in the text?
An infection that occurs during treatment for a primary infection due to overuse of antibiotics
Why are superinfections more likely to occur in patients receiving broad-spectrum antibiotics?
Because broad-spectrum antibiotics kill more normal flora than narrow-spectrum drugs
What is the significance of hospitals as sites of intensive antibiotic use?
Hospitals promote the emergence of extremely drug-resistant organisms
Which mechanism of drug resistance involves decreasing the concentration of a drug at its site of action?
Decreasing active uptake of drugs
What is the primary concern associated with acquired resistance to antibiotics?
Clinical crisis due to ineffective drugs
Which gene codes for a powerful form of β-lactamase that can inactivate various β-lactam antibiotics?
NDM-1 gene
Which drug class disrupts specific biochemical reactions leading to a decrease in the synthesis of essential cell constituents?
Antimetabolites
What is the main impact of drugs that cause nonlethal inhibition of bacterial protein synthesis?
Slowing microbial growth
Which drug is known for increasing the permeability of bacterial cell membranes, causing leakage of intracellular material?
Amphotericin B
Which enzyme does most drugs that suppress viral replication inhibit?
DNA polymerase
What is one of the ways microbes resist certain drugs like tetracyclines and gentamicin?
Decreasing active uptake of drugs
What is the characteristic outcome of drugs that inhibit bacterial cell wall synthesis?
Promotion of bacterial lysis and death
Which drug directly binds to nucleic acids or interacts with enzymes required for nucleic acid synthesis?
Rifampin
What is one of the drawbacks of using multiple antibiotics according to the text?
Possible antagonism of antimicrobial effects
Which of the following is NOT mentioned as an approved indication for antimicrobial prophylaxis?
Treatment of viral infections
Why are serum drug levels monitored during antimicrobial therapy?
To avoid toxicity from excessive levels
Which antibiotics belong to the beta-lactam family according to the text?
Penicillins and cephalosporins
What is the principal adverse effect of penicillins according to the text?
Allergic reactions
Why do bacteria take up excessive amounts of water and rupture when exposed to penicillins?
Because penicillins cause them to burst
What is an important clinical indicator of success in antimicrobial therapy according to the text?
Reduction of fever and resolution of signs and symptoms related to the affected organ system
Why must antimicrobial prophylaxis be carefully considered before administration?
To weigh the benefits against risks like toxicity and allergic reactions
Why are penicillins considered practically ideal antibiotics according to the text?
They are active against a variety of bacteria and have low direct toxicity
What common misuse of antibiotics is highlighted by the CDC?
Treatment for viral infections
Which penicillin has the broadest antimicrobial spectrum among the ones mentioned in the text?
Piperacillin
What is the main reason for the broadened spectrum of penicillins against gram-negative bacilli?
Enhanced ability to penetrate the gram-negative cell envelope
Which organism is NOT susceptible to piperacillin according to the text?
Staphylococcus aureus
What is the primary difference between amoxicillin and ampicillin in terms of acid stability?
Amoxicillin is more acid stable
Which drug can cause bleeding secondary to disrupting platelet function?
Piperacillin
In the United States, which beta-lactamase inhibitor is NOT used as a fixed-dose combination with a penicillin?
Doripenem
What are the three primary factors determining bacterial resistance to penicillins?
Inability of penicillins to reach PBPs, inactivation by bacterial enzymes, and production of PBPs with low affinity for penicillins
What role does the β-lactam ring play in the antibacterial action of penicillins?
Being essential for antibacterial action
What pathogen has developed two distinct types of MRSA over the years?
Staphylococcus aureus
Which type of MRSA is more prevalent between health care-associated MRSA and community-associated MRSA?
Health care-associated MRSA
Which type of penicillins are classified as antipseudomonal penicillins?
Extended-spectrum penicillins
Which bacterium is not susceptible to the antibacterial action of Penicillin G?
Escherichia coli
What is the principal concern associated with the use of Penicillin G?
Allergic reactions
What is the term used to describe the complete antigen that stimulates antibody formation?
Hapten-protein
Why is skin testing important for patients with a history of penicillin allergy?
To determine the likelihood of anaphylaxis
Which characteristic differentiates penicillin V from penicillin G?
Acid stability
Why are cephalosporins avoided in patients with a history of anaphylaxis to penicillin?
Due to the risk of cross sensitivity
What is the primary benefit of desensitization schedules when administering penicillin?
Reduced risk of allergic reactions
What should be readily available during penicillin desensitization procedures to manage potential risks?
Epinephrine
Which drugs are specifically mentioned as effective and safe alternatives for patients with penicillin allergy?
Vancomycin, erythromycin, and clindamycin
What is the primary reason for avoiding penicillinase-resistant penicillins in infections caused by non–penicillinase-producing staphylococci?
Lower efficacy compared to penicillin G
Why are ampicillin and amoxicillin classified as broad-spectrum penicillins?
They cover a wide range of bacterial species
What is the significance of altering the side chain of penicillins by pharmaceutical chemists?
Resistance to beta-lactamases
Which of the following drugs should be used with caution in patients taking other drugs that prolong the QT interval?
Telavancin
What is the mechanism of action of fosfomycin against bacteria?
Disruption of peptidoglycan synthesis
Which of the following bacteria is NOT susceptible to aztreonam?
Staphylococcus aureus
What is the primary reason for the minimal cross-allergenicity of aztreonam with penicillins and cephalosporins?
Little structural resemblance
Which of the following adverse effects is NOT commonly associated with aztreonam?
Vaginitis
How does aztreonam primarily exert its antimicrobial effect?
Inhibition of cell wall synthesis
Why are most first-generation cephalosporins destroyed by β-lactamases?
They lack an extended side chain.
What distinguishes cefiderocol from other cephalosporins mentioned in the text?
It lacks a β-lactam ring.
Why are third-generation cephalosporins considered the most prescribed from the generations mentioned?
They have the broadest antimicrobial spectrum.
Which drug mentioned in the text is specifically tailored for MDR gram-negative infections?
Ceftolozane
What contributes to the highly resistant nature of fifth-generation cephalosporins?
Extended-spectrum beta-lactamases production
What distinguishes second-generation cephalosporins from first-generation ones regarding resistance to β-lactamases?
They possess an extended side chain.
What is the most common adverse reaction seen with cephalosporins according to the text?
Alcohol intolerance
Which cephalosporin is specifically mentioned as being used for surgical prophylaxis?
Cefazolin
Which organisms are primarily targeted by second-generation cephalosporins?
Haemophilus influenzae
Which characteristic sets third-generation cephalosporins apart from the first and second generations?
Gram-negative coverage
In which type of infection are fourth-generation cephalosporins like cefepime particularly effective?
Hospital-acquired pneumonia
Which carbapenem antibiotic is specifically mentioned as not being active against MRSA?
Ertapenem
What makes imipenem unique in terms of its antimicrobial spectrum compared to other antibiotics?
Broad activity against Gram-negative bacilli
What is the mechanism of action of vancomycin against bacterial cells?
Inhibits cell wall synthesis
Why is vancomycin not effective against gram-negative bacteria?
Lacks penetration through gram-negative cell walls
What is the primary adverse effect of telavancin therapy?
Taste disturbance and foamy urine
When should vancomycin dosage be reduced to minimize the risk of renal toxicity?
When serum creatinine level increases by 50%
Which organism is NOT listed as susceptible to vancomycin in the text?
"White man"
What is the primary difference in the approved indications between vancomycin and telavancin?
Telavancin for skin infections, Vancomycin for respiratory infections
What differentiates telavancin from vancomycin in terms of mechanism of action?
"Telavancin binds to bacterial cell membrane"
"Red man syndrome" associated with vancomycin is primarily characterized by:
"Flushing and rash"
"Red man syndrome" associated with vancomycin can be caused by:
"Rapid infusion"
This quiz provides an overview of anaphylactic reactions, focusing on penicillin allergy. Learn about the incidence and development of allergies to small molecules like penicillin. Explore how small molecules trigger antibody formation.
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