Microbiology: Chapter 12

Which of the following drugs is used to treat influenza infections? Amantadine Acyclovir AZT Fuzeon Indinavir

Amantadine

The antibiotics listed here all have similar minimum inhibitory concentrations. Choose the antibiotic that would be the best option for treatment. Antibiotic W Therapeutic Index = 5 Antibiotic X Therapeutic Index = 20 Antibiotic Y Therapeutic Index = 100 Antibiotic Z Therapeutic Index = 10

Antibiotic Y Therapeutic Index = 100

Which of the following is a bacterial cell wall inhibitor found in over-the-counter antibacterial ointments.

Bacitracin

________ is an anti-HIV drug that inhibits viral attachment to host cells.

Enfuvirtide

Metronidazole is used to treat which three of the following protozoan pathogens? Candida albicans Entamoeba histolytica Plasmodium Giardia lamblia Trichomonas vaginalis

Entamoeba histolytica Giardia lamblia Trichomonas vaginalis

True or False: Drugs that are selectively toxic kill the host cells without harming the microbial cells.

False

True or False: Sulfonamides are derived from fungi.

False

True or False: Drug resistance can occur when a patient's immune system becomes reactive to a drug.

False....drug resistance can occur when a bacterium stops being susceptible to an antibiotic

True or False: Antimicrobial drug damage is always permanent.

False....it can be short-term and reversible or permanent

True or False: Most antiviral agents work by destroying active viruses

False....most antiviral agents work by blocking an essential viral activity

True or False: Sulfonamide drugs work by disrupting protein synthesis.

False...sulfonamide drugs work by disrupting folic acid synthesis

________ generations of cephalosporins exist, and each exhibit varying levels of antibacterial activity.

Five

Which of the drugs mentioned inhibits DNA polymerase? Foscarnet Protease inhibitors Amantadine Interferon

Foscarnet

Select which non-beta-lactam phosphoric acid agent is used today as an alternative treatment for urinary tract infections caused by enteric bacteria. Fosfomycin Tetracycline Penicillin Iripenem

Fosfomycin

Of all the antiviral drugs mentioned, which is actually produced by the host? Interferon AZT Foscarnet Amantadine

Interferon

The _______ ________ technique is an agar diffusion test to determine antibiotic susceptibility of a particular bacterial strain. therapeutic index Kirby-Bauer southern blot Sanger method

Kirby-Bauer

Which two of the following statements regarding multidrug resistance (MDR) pumps are correct? MDR pumps are located in the periplasmic space MDR pumps work by active transport MDR pumps are powered by ATP hydrolysis MDR pumps are encoded on plasmids

MDR pumps work by active transport MDR pumps are encoded on plasmids

Select the statements that reflects problems that have led to the worldwide problem of managing antimicrobial drugs. Many prescriptions are given to control upper respiratory infections typically caused by viruses physicians use a "shotgun" approach to treat minor infections drugs are prescribed without susceptibility testing narrow-spectrum drugs are used to treat most illnesses

Many prescriptions are given to control upper respiratory infections typically caused by viruses physicians use a "shotgun" approach to treat minor infections drugs are prescribed without susceptibility testing

Determining which antimicrobial agent is most effective against an infectious microbe is essential when the infection is caused by bacteria that commonly show resistance, such as (choose two): Listeria Neisseria Penicillium Staphylococcus Bacillus

Neisseria Staphylococcus

During which stage of viral replication does amantadine exert its inhibitory effect? Synthesis of capsid proteins Viral assembly Penetration and uncoating Synthesis of nucleic acids

Penetration and uncoating

Choose the antimicrobial category that is most selectively toxic. Sulfonamides that inhibit folic acid synthesis Aminoglycosides that inhibit protein synthesis Penicillins that inhibit cell wall synthesis Polymyxins that interfere with cell membrane structure and function Fluoroquinolones that interfere with nucleic acid structure and function

Penicillins that inhibit cell wall synthesis

Class of treatments with an example

Prebiotic - fructans encourage the growth of Bifidobacterium and discourage potential pathogens Probiotic - used to replace microbiota lost during antimicrobial chemotherapy

_____ are preparations of live microbes used as a preventative or therapeutic measure to displace or compete with potential pathogens.

Probiotics

Determining which antimicrobial agent is most effective against an infectious microbe is essential when the infection is caused by bacteria that commonly show resistance, such as (choose two): Streptococcus pneumoniae Streptomyces species Enterococcus faecalis Pseudomonas aeruginosa Thermus aquaticus

Streptococcus pneumoniae Enterococcus faecalis

Tube Dilution Test What do the X symbols in the circles represent? The dose at which the organisms will grow The minimum dose at which that drug inhibits that organism The maximum dose at which that drug inhibits that organism The minimum dose at which that drug inhibits any organism

The minimum dose at which that drug inhibits that organism

Resistance to which of the following drugs develops when microbes deviate from the usual pathway that leads to the production of folic acid?

Trimethroprim Sulfonamides

True or False: An R factor is a type of plasmid that confers antibiotic resistance.

True

True or False: An antibiotic that disrupts the host's normal biota can cause a superinfection.

True

True or False: Biofilms are difficult to treat and do not always respond to antibiotics.

True

True or False: Drug resistance is where microbes begin to tolerate an antimicrobial agent at a level which would normally be inhibitory.

True

True or False: Vancomycin is more widely used to treat gram-positive bacteria that have become resistant to methicillian, a problem especially in hospitals and the community at large.

True

True or False: Anaphylaxis is the pronounced allergic reaction to antigen that leads to severe respiratory and cardiac complications

True

True or False: One goal of antimicrobial drug therapy is to inhibit the replication of the microbe.

True

When AZT is present, which enzyme is inhibited? Viral protease Host RNA polymerase Viral reverse transcriptase Host DNA polymerase

Viral reverse transcriptase

Microbial resistance to drugs is acquired through conjugation transformation transduction all of these

all of these

Patients taking penicillin may experience _______ reactions.

allergic

Which of the following needs to be considered when selecting an antimicrobial? allergies patient's birthplace other medications being taken age of the patient patient's health history

allergies other medications being taken age of the patient patient's health history

Which two of the following statements concerning global transport and the spread of resistant microbes are correct?. an air traveler w drug resistant TB can spread it on other continents in a short time food products are sterilized before shipping to avoid transfer of microbes around the world drug resistance is primarily a problem in the developing countries of Africa Bacterial, viral, fungal, and protozoal diseases are all showing an increase in drug resistance worldwide

an air traveler w drug resistant TB can spread it on other continents in a short time Bacterial, viral, fungal, and protozoal diseases are all showing an increase in drug resistance worldwide

The consequence of the body metabolizing penicillin to form the byproduct benzylpenicilloyl is the development of

an allergy

A particular microbe produces a substance that kills another microbe in its environment. This is an example of ______.

antagonism

A profile of antimicrobial sensitivity is called a(n)

antibiogram

A compound synthesized by bacteria or fungi that destroys or inhibits the growth of other microbes is a/an synthetic drug antibiotic interferon competitive inhibitor

antibiotic

A(n) _____ 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 organisms.

antimicrobial

______ is an all-inclusive term for any drug used to fight an infection, regardless of its origin or type.

antimicrobial

Actinomycetes are a group of filamentous, fungus-like _____

bacteria

Which two of the following statements are correct regarding the use of bacteriophage to treat infections? bacteriophages have been shown to be active against microbes in biofilms bacteriophages are effective against bacteria and fungi bacteriophages are specific to a single species of microbe bacteriophages cannot infect antibiotic resistant microbes

bacteriophages have been shown to be active against microbes in biofilms bacteriophages are specific to a single species of microbe

Which statement is not an aim in the use of drugs in antimicrobial therapy? The drug should have selective toxicity be active even in high dilutions be broken down and excreted rapidly be microbicidal

be broken down and excreted rapidly

Drugs that prevent the formation of the bacterial cell wall are quinolones beta-lactams tetracylines aminoglycosides

beta-lactams

Cephalosporins are ________-spectrum antibiotics.

broad

Fluoroquinolones are ________-spectrum drugs.

broad

Mebendazole and albendazole are _________-spectrum drugs used to treat several roundworm intestinal infections

broad

An antimicrobial drug that is effect against a very diverse array of bacteria is described as _______ spectrum, whereas a drug that is very selective for just a few different types of bacteria is described as ____ spectrum. broad, narrow long, short effective, ineffective wide-range, limited

broad, narrow

Organisms resistant to penicillin and _____ often produce beta-lactamases that hydrolyze the beta-lactam ring structure of the antibiotic

cephalosporins

A ______ drug is an agent used in the treatment, relief, and prophylaxis of a disease.

chemotheraputic

Order the steps involved in testing a microbe for susceptibility to antibiotics. inoculate a series of tubes with a uniform sample of the culture incubate the tubes, then examine them for growth dilute the antibiotic in a series of tubes

dilute the antibiotic in a series of tubes inoculate a series of tubes with a uniform sample of the culture incubate the tubes, then examine them for growth

Which two of the following sources of information may contribute to an "informed best guess" for beginning antimicrobial therapy? direct examination of body fluids culture of the infecting microbe antibiotics susceptibility of the infecting microbe analysis of patient symptoms

direct examination of body fluids analysis of patient symptoms

Which three types of information are important to consider when choosing an antibiotic for a patient?

drug allergies underlying liver disease possibility of pregnancy

The production of beta-lactamases is an example of which mechanism of drug resistance? increased drug permeability altered internal metabolic pathway increased drug binding sites drug inactivation

drug inactivation

Natural selection is a process in which ________ factors, such as drugs present, place pressure on organisms; traits that improve survival tend to spread within the population.

environment

The antibiotic group tetracyclines are named for their regular group of _____ rings.

four

Most antibiotics are common metabolic products of ____ and _____.

fungi and bacteria

Select which statements reflect factors in modern day society that directly contributes to the development of drug resistant microorganisms. prudent use of antibiotic and antiviral drugs global transportation misuse of universal precautions in hospital settings use of antibiotics in animal feed export of drugs to developing countries where usage is not strictly monitored culture and sensitivity testing used on all patient specimens

global transportation misuse of universal precautions in hospital settings use of antibiotics in animal feed export of drugs to developing countries where usage is not strictly monitored

Which two of the following statements concerning global transport and the spread of resistant microbes are correct? global travel means that drug resistance can spread rapidly drug resistance is increasing in Asia, but not in the western hemisphere food products often carry microbes from their places of origin bacterial diseases, but not fungal or protozoal diseases, are showing an increase in drug resistance

global travel means that drug resistance can spread rapidly food products often carry microbes from their places of origin

Which of the following are NOT primary sites for action of antimicrobial drugs in bacteria? cell membrane ribosomes nucleic acids gogli apparatus (bodies) mitochondria cell wall

gogli apparatus (bodies) mitochondria

Which of the following microbes are regularly treated with tetracyclines? gram-negative rods and cocci mycobacterium mycoplasmas gram-positive rods and cocci spirochetes rickettsias

gram-negative rods and cocci mycoplasmas gram-positive rods and cocci spirochetes rickettsias

High selective toxicity yields a low TD50 value and therefore a low TI high TD50 value and therefore a high TI low TD50 value and therefore a high TI high TD50 value and therefore a low TI

high TD50 value and therefore a high TI

An antimicrobial drug with a ___ therapeutic index is a better choice than one with a ___ therapeutic index. low, high high, low

high, low

Protease inhibitors ____. inhibit processing of long polypeptide chains inhibit synthesis of interferons inhibit reverse transcriptase inhibit DNA polymerase inhibit processing of long polypeptide chains

inhibit processing of long polypeptide chains

Which of the following is NOT a general mechanism of antimicrobial drug actions? inhibiting protein synthesis inhibiting electron transport systems interference of cell membrane function and structure inhibiting cell wall sythesis inhibiting nucleic acid structure or function

inhibiting electron transport systems

Fungi have three mechanisms for becoming antibiotic-resistant: interfering RNA biofilm formation genetic drift spontaneous mutation horizontal transfer quorum sensing

interfering RNA spontaneous mutation horizontal transfer

_________ is a normal human glycoprotein produced in response to immune stimuli and can be used therapeutically to fight viruses and cancer

interferon

Polymyxin B and E are toxic to the _______

kidney

Which of the following is NOT a clinical problem associated with tetracyclines? diarrhea discoloration of tooth enamel enterocolitis kidney damage reactions to sunlight

kidney damage

Rifampin is important in treating which two infectious diseases? bubonic plaque leprosy Rocky Mountain spotted fever impetigo tuberculosis

leprosy tuberculosis

Quinine, a drug derived from cinchona trees, is used to treat

malaria

Which two factors contribute to the spread of antibiotic resistant genes in the hospital environment? many pathogens are found in hospitals potted plants and soils bring microbes into the hospital hospital pharmacies dispense many types of antibiotics not all hospital workers follow infectious control guidelines

many pathogens are found in hospitals not all hospital workers follow infectious control guidelines

Polyenes bind to fungal DNA polymerases membranes cell wall components ribosomes

membranes

The lowest concentration of a drug that visibly inhibits growth is called the _________ _________ ________ or MIC.

minimum inhibitory concentration

Many bacteria possesses _______ that actively transports drugs out of the cells. multidrug resistant (MDR) pumps antibiotic binding (ABC) transporters permeability receptors

multidrug resistant (MDR) pumps

An antimicrobial that is effective against a limited array of microbial types is called a ________ spectrum drug.

narrow

Antibiotics that affect _________ __________ synthesis specifically affect the processes of replication and transcription

nucleic acid

Acyclovir is an example of an antiviral agent that mimics the structure of nucleotides peptidoglycan reverse transcripte proteases

nucleotides

The ______ _________ of a cell envelope of certain gram-negative bacteria is a natural blockade against some penicillin derivatives.

outer membrane

A _____ is an enzyme secreted by certain bacteria that cleaves the beta-lactam ring of penicillin and cephalosporin and thus provides resistance against the antibiotic. (choose two) penicillinase beta-lactamase lipase DNA polymerase

penicillinase beta-lactamase

Cephalosporins closely resemble which group of antibiotics in terms of structure and function? macrolides penicillins tetracyclines aminoglycosides sulfonamides

penicillins

The cell wall is a rigid structure found in bacteria that is made of _____ and lies just outside the cell membrane.

peptidoglycan

Phage therapy is a technique that uses chemicals to destroy phages infecting human cells. chemicals to foster the growth of beneficial phages in the body. phages to foster the growth of normal biota phages to target pathogenic bacteria in the body.

phages to target pathogenic bacteria in the body.

Some drugs interact with sunlight resulting in a skin inflammation called __________.

photodermatitis

R factors are _______ that contain a code for _________. genes, replication plasmids, drug resistance transposons, interferon plasmids, conjugation

plasmids, drug resistance

Aztreonam is used to control pneumonia septicemia gastroenteritis urinary tract infections tuberculosis

pneumonia septicemia urinary tract infections

Bacillus polymyxa is the source of

polymyxins

_______ are nutrients used to stimulate the growth of favorable biota in the intestine.

prebiotics

Which of the following modes of action would be most selectively toxic? interrupting ribosomal function dissolving the cell membrane preventing cell wall synthesis inhibiting DNA replication

preventing cell wall synthesis

Fecal transplants represent an adapted use of GMOs prebiotics antibiotics probiotics

probiotics

The use of a drug to prevent imminent infection of a person at risk is called _______

prophylaxis

Tetracycline inhibits _____ synthesis.

protein

Tetracyclines inhibit replication of DNA protein synthesis cell formation folic acid

protein synthesis

Which of the following drugs was the principal treatment once used for malaria? metronidazole amphotericin B chloramphenicol fuzeon quinine

quinine

Erythromycin resistance is associated with an altercation of an organism's 50S ________ subunit.

ribosomal

The fusion of a natural microbial product with a preselected molecule results in the formation of a(n) _____ antibiotic.

semisynthetic

______ antibiotics are drugs that, after being naturally produced by bacteria, fungi, or other living sources, are chemically modified in the lab.

semisynthetic

The MIC is the ______ of a drug that is required to inhibit growth of a microbe. largest concentration standard dose smallest concentration lowest dilution

smallest concentration

Aminoglycosides are composed of one or more amino acids alcohols sugars

sugars

A(n) ____ is an infection occurring during antimicrobial therapy that is caused by an overgrowth of drug-resistant microorganisms.

superinfection

Antibiotic ______ is a process that occurs when antibiotics interact in ways that enhance or magnify each other.

synergism

An antimicrobial drug that is chemically synthesized in the laboratory is called a ______ drug.

synthetic

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

systemic

Be able to identity common antibiotics and their metabolic targets targets the cell wall targets protein synthesis targets folic acid synthesis targets DNA or RNA targets cell membrane

targets the cell wall - Penicillins (penicillin G, ampicillin, amoxicillin) Cephalosporins (cefotaxime, defaclor) Carbapenems (Aztreonam) Bactracin, Isoniazid, Vancomycin targets protein synthesis - Aminoglycosides (streptomycin) Tetracyclines, Glycylcyclines, Macrolides (Erythromycin, Azithromycin) targets folic acid synthesis - Sulfonamides (Trimethropin) targets DNA or RNA - Fluoroquinolones (ciprofloxacin, trovafloxacin) Rifamycin (rifampin) targets cell membrane - Polymyxins (Daptomycin, polymyxins B and E)

Which two antibiotics should not be prescribed with oral contraceptives, as they can abolish the contraceptive's effects? tetracycline rifampin penicillin aminoglycosides isoniazid

tetracycline rifampin

Glycylcyclyines are newer derivatives of

tetracyclines

Which of the following drugs are linked to the development of superinfections? tetracyclines acyclovir penicillin cephalosporin

tetracyclines penicillin cephalosporin

Why is drug testing in fungal infections unnecessary? there are no good antifungals available to test the best antifungal agents target all fungi most fungi are susceptible to antibiotics fungi don't grow well on agar in Petri dishes

the best antifungal agents target all fungi

The addition of DNase to biofilms can help with antibiotic penetration because DNase prevents the biofilm bacteria from taking up the DNA by transformation the biofilm extraceullar matrix includes DNA from lysed cells certain antibiotics act as competitors of DNase and bind its active site

the biofilm extraceullar matrix includes DNA from lysed cells

When interferon from one cell attaches to a second cell, the recipient cell is able to kill bacteria the recipient cell makes enzymes that prevent cell metabolism the recipient cell makes enzymes that degrade mRNA and prevent viral protein synthesis the second cell now makes interferon and saves itself

the recipient cell makes enzymes that degrade mRNA and prevent viral protein synthesis

Which of the following are the categories of major drug side effects? toxic damage to tissue autoimmune reactions normal flora disruption allergic reactions

toxic damage to tissue normal flora disruption allergic reactions

The therapeutic index is the ratio of the _____ dose of the drug to its ____ dose that is used to assess the safety and reliability of the drug.

toxic, effective

Select the types of horizontal transfer that can allow for bacteria to acquire antibiotic resistance genes. Check all that apply. conjugation cavitation transposition replication transformation transduction

transformation conjugation tranposition transduction

Synercid binds to ribosomes inhibiting the process of _______.

translation

True or False: Drugs that are effective against fungi have a strong possibility of being toxic to humans because both organisms are eukaryotes.

true

Most antihelminthic drugs function by weakening the worms so they can be flushed out by the intestine inhibiting worm metabolism blocking the absorption of nutrients inhibiting egg production

weakening the worms so they can be flushed out by the intestine or inhibiting worm metabolism