Chapter 12: drugs microbes host

Identify the active part of the penicillin structure.

Beta-lactam ring

"formation" is produced by some microbes which in turn makes them resistant to some antimicrobial compounds and the shear force of moving liquids?

Biofilm

Which of the following are quinolones?

Ciprofloxacin Norfloxacin

Which of the following are side effects associated with antimicrobial drugs?

Damage to host tissues due to toxicity Disruption of normal microflora Allergic reactions

True or false: Natural selection for drug-resistant forms of bacteria is rare.

False It is fairly common

True or false: Drug resistance only arises from an organism gaining the genetic information for the resistance from another organism.

False, Reason: It can also arise from a spontaneous mutation within the chromosomes.

True or false: The most effective drugs that treat infections caused by flukes, tapeworms, and roundworms eradicate the adult stages of the organisms.

False, Reason: They typically block metabolism at all stages of the life cycle rather than eradicate the adult worms.

Interferon is produced primarily by ___ and _____ in response to various immune stimuli.

Fibroblasts and leukocytes

Amphotericin B is considered highly versatile in that it is effective in treating most infections caused by which of the following?

Fungi

Which of the following bacteria are normally not tested for drug susceptibility?

Group A streptococci

Which of the following is not a side effect associated with antimicrobial drugs?

Host cell metabolism of drug

Advantages of semisynthetic penicillins over natural penicillins include which of the following?

Increased movement across gram-negative cell walls Increased spectrum

_____chemotherapy is the use of chemotherapeutic drugs to control infections and diseases caused by many types of microorganisms.

Antimicrobial

Which are antiviral drugs used to treat influenza?

Tamiflu Relenza Xofluza

If the bacterium causing a sore throat is Streptococcus pyogenes, a physician can normally prescribe the antibiotic,___.

Penicillin

True or false: Antiviral drugs prevent penetration into a host cell, block transcription and translation, and prevent maturation of viral particles

True: Reason: Antiviral drugs prevent the replication of viral particles.

Aztreonam is used to control which of the following conditions?

Urinary tract infections Pneumonia Septicemia

Which anti-influenza medication blocks the initiation of viral RNA synthesis?

Xofluza

Direct examination of body fluids, sputum, and stool can provide a rapid detection method for which of the following?

bacteria and fungi

Tetracycline is an example of which type of drug?

broad spectrum

Use of which type of antibiotic can have far reaching affects on beneficial resident species?

broad spectrum

The tolerance of an antimicrobial agent at a level which would normally be inhibitory is called which of the following?

drug resistance

The most effective drugs used to treat infections caused by flukes, tapeworms, and roundworms inhibit ______ at all stages of the life cycle rather than eradicating the adult worms.

metabolism

Drug therapy may fail because the infection is caused by a ____ culture (more than one species)

mixed

Drug resistance occurs with spontaneous _____ or gene transfer from another species.

mutations

An antibiotic that is only effective against a limited array of different microbes is called a ____ spectrum antibiotic.

narrow

Bacitracin is an antibiotic with which spectra of activity?

narrow

Which term describes the process of some microbes dying while others live in the presence of antimicrobial agents?

natural selection

The outer membrane of some Gram- _____ bacteria act as natural barriers to some drugs.

negative

Aztreonam is often used by patients who are allergic to which antibiotic?

penicillin

Which of the following is an example of drug that blocks bacterial cell wall synthesis and exhibits excellent selective toxicity?

penicillin

When these two drugs are used in combination nephrotoxic effects are increased

penicillins and cephalosporins

Which of the following antibiotics contain the beta-lactam ring?

penicillins and cephalosporins

The cell walls of most bacteria are composed primarily of which of the following?

peptidoglycan

Tetracyclines inhibit which of the following?

protein synthesis

A viral enzyme that converts single-stranded RNA into double-stranded DNA is called ________.

reverse transcriptase

The tetracyclines bind to which of the following structures?

ribosome

Approximately what percent of infections involve biofilms?

60%

Which of the following bacteria are routinely tested for drug susceptibility?

Aerobic Gram-negative enteric bacilli Enterococcus faecalis Staphylococcus sp.

Which two semisynthetic penicillins can be used against Gram-negative bacteria?

Amoxicillin Ampicillin

Synercid binds to ribosomes inhibiting the process of _____.

Elongation

_____analogs are structurally similar to the natural substrate and compete with it for the active site on the enzyme.

Metabolic

Identify the three major modes of action of antiviral drugs.

Preventing virus maturation Blocking virus transcription and translation Barring virus penetration into host cell

The ending -floxacin is used for which category of drugs?

Quinolones

Which of the following are the three factors that should be known before selecting an antimicrobial drug?

The nature of the infecting agent The overall health of the patient The sensitivity of the infecting agent

What is the overall goal of antimicrobial chemotherapy?

To destroy the infective agent without harming the patient

True or false: Microorganisms that produce antibiotics in their natural habitat may have a selective advantage over neighboring microbes.

True

True or false: Most tissues are susceptible to adverse effects caused by the use of antimicrobial therapy.

True

True or false: The nature and sensitivity of the microorganism need to be considered before antimicrobial treatment begins.

True

Which of the following is a hypersensitive response to a particular substance by the immune system?

allergy

Which of the following is a substance produced by natural metabolic processes of some microorganisms that can inhibit or kill other microorganisms?

antibiotic

An antibiotic that is effective against a wide variety of microbial types is called a _____ spectrum antibiotic.

broad

Which of the following structures in bacteria protect the cell from lysis (rupture) in hypotonic environments?

cell wall

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

Reverse transcriptase is a retroviral enzyme that does which of the following?

converts RNA to DNA

The inability of a drug to _____ into a body compartment, such as the brain or joints, will render the drug ineffective.

diffuse

An allergy is caused by a hypersensitive response from which system?

immune

Which groups of people may have greater risks to antimicrobials?

infants, elderly, pregnant women

Which of the following is a normal human glycoprotein produced in response to immune stimuli and can be used therapeutically to fight viruses and cancer?

interferon

Nephrotoxic drugs are toxic to which of the following?

kidneys

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

Synercid is effective against members of which genera?

staphylococcus, enterococcus, streptococcus

When antimicrobial therapy destroys beneficial resident microbes and allows an overgrowth of drug-resistant microorganisms, it is called which of the following?

superinfection

Amphotericin B is one of the few drugs that can be injected to treat _____ fungal infections such as cryptococcus meningitis.

systemic