Flashcards in Test 3 Deck (81):
Chemotherapeutic agents that target bacterial cell wall synthesis work only on cells that are metabolically active and
A drug that only kills or inhibits a limited number of pathogens is said to be ___________, whereas those that are effective against many pathogens are _____________.
narrow spectrum, broad spectrum
If an antibiotic kills a bacterial pathogen, it is said to be ___________; if it only inhibits the growth of the bacterial pathogen, it is considered to be _____________.
Lipopolysaccharide, a component of _________________ bacteria cell walls, is release upon call wall destruction and can cause systemic infections in humans
____________ are antimicrobial chemicals that are made naturally by certain microorganisms.
Indiscriminate use of antibiotics can lead to the destruction of our resident microbiota and allow overgrowth of non-bacterial microbiota such as __________ ___________.
_______________ is the lowest temperature that will kill all of the cells (sterilize) in a broth culture in 10 minutes.
Thermal death point
______ heat is more effective in killing microbes than ____ heat.
Formaldehyde gas is commonly used as a 37% solution called __________.
The minimum amount of time required to sterilize a set volume of liquid at a set temperature is known as ______________________.
Thermal death time
_____________ is a process in which microbes are quickly frozen then dried.
When all organisms, as well as any endospores have been removed, a specimen is classified as __________.
If an antimicrobial agent is bacteriostatic:
multiplication of microorganisms will resume after removal of the agent
Which of the following is an example of sanitization?
A public toilet is treated with disinfectants. A surgeon washes his hands before surgery. Heat is used to kill potential pathogens in apple juice. An autoclave is used to prepare nutrient broth. All of these are examples of sanitization.
A public toilet is treated with disinfectants.
Antimicrobial agents that interfere with nucleic acids would also have a direct effect on_________.
Which of he following would have the highest resistance to physical and chemical control?
Bacterial vegetative cells, bacterial endospores, protozoan cysts, fungal sexual spores, or enveloped viruses.
Which of the following affects the elimination of bacteria from an object?
Number of bacteria present, host/host material, concentration of the antimicrobial agent, temperature and pH, or all of the above
all of the above
Extremely high temperatures exceeding the maximum are ___________, whereas temperatures below the minimum tend to have ____________ effects.
In controlling microbial growth, cold temperatures generally
The temperature-pressure combination for an autoclave is
121 degrees C and 15 psi
An effective method for sterilizing heat-sensitive liquids is
The type of antimicrobial drug that would be least toxic to humans is a drug that
inhibits synthesis of the cell wall
It is inappropriate to prescribe antibacterial agents to treat cold or flu because
These diseases are cause by viruses.
Which of the following is the ultimate means of sterilization?
autoclaving, radiation, incineration, desiccation, or none of these
Which statement is NOT an aim of the use of drugs in antimicrobial chemotherapy?
selective toxicity, active even in high dilution, insoluble in body fluids, microbicidal, all of these are important in antimicrobial therapy
insoluble in body fluids
Penicillin and other beta-lactams kill bacteria by affecting
The cell wall
Streptomycin and tetracycline kill bacteria by affecting
B-lactam antibiotics have an effect on which of the following type(s) of cells
What is the mode of action of erythromycin?
Inhibit protein synthesis.
Erythromycin is particularly effective for treating diseases due to viruses and fungi.
Antibiotic abuse encourages the development of antibiotic resistant strains such as MRSA.
Antibiotics can always be taken without risk or worry about side effects on the body.
A "broad spectrum" antibiotic would be one that attacks many different microbial cell sites.
Whenever an organism grows in a host, it causes disease
The number of microorganisms that must be taken into the body for disease to occur is essentially the same for all infectious agents.
An opportunistic pathogen can invade and cause disease in persons whose host defenses are compromised.
Autoclaving and pasteurization are two processes that are very effective for sterilization.
The best description of the relationship we have with our resident microbiota is
In a commensal relationship
one benefits, and one is neither harmed nor benefited.
The human body typically begins to be colonized by its normal microbiota
during and immediately after birth
The body site with resident microbiota that produces beneficial body products including vitamin K and other vitamins is the
Infection occurs when
Pathogens enter and multiply in body tissues
Normal microbiota may be found in all the following environments except:
The stomach, the pharynx, the vagina, the upper respiratory tract, or the large intestine
The relationship between the body and its normal microbiota
is an example of symbiosis
Fungi and yeasts are not members of the normal microbiota.
The predominant organisms of our normal microbiota in lung alveoli are viridans streptococci.
subjective characteristics of a disease that can only be felt by the patient
Growth of Lactobacillus on the surface of teeth is an example of __________.
normal microbiota becoming opportunistic pathogens
A toxin able to induce septic shock, fever, and pain due to cell wall degradation of the gram negative Pseudomonas aeruginosa in the blood is
what is the correct sequence of events in infectious disease?
incubation, prodromal period, illness, decline, convalescence
Virulence factors include all of the following except:
capsules, exoenzymes, endotoxins, ribosomes, or exotoxins
Microbial hyaluronidase, coagulase, and streptokinase are examples of
According to the CDC, what would be classified as a Class 4 microorganism?
The total number of deaths in a population due to a disease is the
Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are
An example of a fomite is
a contaminated utensil
After walking through a field, your feet have picked up fungal spores and pathogenic bacteria. Your feet are
Hospital acquired infections are called
Lipopolysaccharide consists of lipid A and O antigen and, as a component of Gr - bacterial cell walls, is released upon cell lysis and causes systemic infections in humans. This component is classified as a(n)
A positive antibody test for HIV would be a ________ of infection.
Present more or less continuously in a particular location
Occurs occasionally or in scattered incidences
attacks many people at same time in same place
spread of an epidemic across continents
Condition in which pathogenic microbes penetrate and multiply in the tissues of a host
several agents establish at the same site at same time
Condition which spreads to several body sites and tissue fluids
condition in which agent leaves local site and moves to another tissue
condition which remains confined to a specific tissue
progress slowly, persist of long periods of time
rapid onset, severe effects, short duration
cause by normal microbiota; typically follows an infection by a true pathogen
Yes, it would indicate infection because there are no normal microbiota that should live in the urinary tract except for in the urethra.
Yes, it would indicate infection because there should be no microbiota living in the lower respiratory tract.
Yes, it would indicate infection because there should not be anything in the CSF. It should be a sterile environment.
No it does not indicate infection because there are normal microbiota that can be found in the throat that are not causing an infection.
No, because there are normal microbiota that are found in the large intestine and can be seen in stool.
Yes, because there should not be any bacteria found in the blood. Blood is supposed to be sterile, and any bacterial growth would indicate infection.
A new bacterium has been secretly engineered and released by aerosol into the population of a large metropolitan city as part of a terrorist scheme. This bacterium produces a lethal neurotoxin, several horrific enzymes, grows rapidly, and has a capsule. After several days, no unusual illnesses have been reported and the terrorists scheme has failed. What factors could the terrorist bioengineers have overlooked?
1. Dehydration of the bacterium due to the aerosol release causing dry capsules and easier digestion by lysosomes.
2. Too high or low optimum growth temperature
3. Neurotoxins may not bind to human cell receptor sites