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149 terms

Micro Exam 2 Questions

STUDY
PLAY
Microbiological contaminants are best described as
any and all microbes present on or in a substance.
Physical agents for controlling microbial growth include all the following except
hydrogen peroxide.
Which of the following microbial forms have the highest resistance to physical and chemical controls?
fungal spores
The process that destroys or removes all microorganisms and microbial forms including bacterial endospores is
sterilization.
The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is
sanitization.
The use of a physical or chemical process to destroy vegetative pathogens is
disinfection.
The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is
antisepsis.
Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is
sterilization.
Which of the following types of control agents would be used to achieve sterility?
bactericide
Which is correct regarding the rate of microbial death?
only older cells die in a culture
Sterilization is achieved by
flash pasteurization.
Dry heat
includes tyndallization.
Endospores can be killed by
dry heat at 170° C for 2 hours.
The minimum sterilizing conditions in a steam autoclave are
71.6° C for 15 seconds.
The shortest time required to kill all the microbes in a sample at a specified temperature is called the
None of the choices are correct.
Disinfection of beverages such as apple juice, milk, and wine, is optimally achieved by
boiling water.
Electrons are ejected from atoms in cells when organisms are exposed to
ethyl alcohol.
Which of the following items are typically irradiated in order to kill microbes?
human tissues such as heart valves and skin
HEPA filters are used to remove microbes from
air.
Which of the following does not contain a heavy metal?
zinc
All of the following are phenols or phenolics except
hexachlorophene.
The easiest microbial forms to kill or inhibit are
endospores.
Which control method would not be a suitable choice for killing mycobacteria in a capped culture tube?
ultraviolet (germicidal) light
All of the following pertain to hypochlorites except
found in iodophors.
Which of the following is not used as an antiseptic?
aqueous glutaraldehyde
Iodophors include
Betadine.
The compound that is an organic base containing chlorine and two phenolic rings, and is used increasingly for wound degerming, neonatal washes, handscrubbing, and prepping surgical skin sites is
chlorhexidine.
Alcohols
All of the choices are correct (denature proteins when in a 50 - 95% alcohol-water solution, disinfect items soaked in alcohol, are skin degerming agents, at 50% or higher concentrations dissolve cell membrane lipids)
Which is mismatched?
Merthiolate - silver
All of the following are correct about iodophors except
this formulation allows a quick release of free iodine.
The sterilizing gas used in a special chamber is
ethylene oxide.
The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to O2 gas is
Cidex.
All the following are correct about detergents except
they are active in the presence of organic matter.
Ethylene oxide is
sporicidal.
Which of the following is being used to replace hypochlorites in treating water because of the possibility of cancer-causing substances being produced?
chloramines
Which of the following chemicals is a disinfectant for soft contact lenses?
hydrogen peroxide
Which of the following is officially accepted as a sterilant and high-level disinfectant?
glutaraldehyde
All of the following are correct about food irradiation except
no irradiated food can be sold without clear labeling.
All of the following are benefits of food irradiation except
it makes the food less nutritious.
All of the following are methods of disinfection or sterilization except
lyophilization.
Historically, which of the following was instilled into the eyes of newborn infants to prevent gonococcal infections?
silver nitrate
Which common hospital pathogen is able to grow abundantly in soap dishes?
Pseudomonas
All of the following are correct about the autoclave except
It is effective for sterilizing powders, oils, and waxy substances.
Which of the following types of agents targets protein conformation?
alcohol
Paracoccidioides is
endemic to regions of Central and South America.
Which is mismatched?
tinea capitis - ringworm of the beard
Transmission of tineas include
All of the choices are correct (human to human, animal to human, soil to human, fomites to human)
Entamoeba histolytica is acquired by
All of the choices are correct (ingestion of cysts of the pathogen, contaminated food, contaminated water, anal-oral sexual contact)
Amebiasis is a disease of the
intestines and often the liver.
Human asymptomic carriers are common in
amebiasis and trichomoniasis.
Diseases transmitted by vectors include
trypanosomiasis and leishmaniasis.
The large intestines of pigs are the primary reservoir of the pathogen that causes
balantidiasis.
Which of the following is a large ciliate?
Balantidium coli
Which of the following has four pairs of flagella?
Toxoplasma gondii
Which of the following is an apicomplexan parasite?
Toxoplasma gondii
Which of the following is a sexually transmitted disease?
trichomoniasis
Which of the following causes serious congenital disease from transplacental transmission?
toxoplasmosis
All of the following can be transmitted by drinking contaminated water except
babesiosis.
Amebiasis symptoms include
bloody, mucus-filled stools, fever, diarrhea, and weight loss.
The symptoms that occur in cyclic 48 to 72 hour episodes in a malaria patient are
chills, fever, and sweating.
Most cases of toxoplasmosis in patients that are not immunocompromised have the following symptoms:
sore throat, low grade fever, and swollen lymph nodes
Trichomonas vaginalis
All of the choices are correct (does not produce cysts, in males causes urethritis, in females causes vaginitis with a foul-smelling discharge, has four flagella and an undulating membrane)
Giardiasis involves
symptoms of abdominal pain, flatulence, and diarrhea.
African sleeping sickness is caused by
Trypanosoma brucei.
Chagas disease involves transmission of the pathogen by the
tsetse fly.
Transmission of the pathogen of leishmaniasis is by the
phlebotomine (sand) fly.
The vector involved in African sleeping sickness is the
tsetse fly.
The large, fully formed developmental stage of a hemoflagellate is called the
trypomastigote.
Which is incorrect about malaria?
merozoites enter and multiply in liver cells
This is a zoonosis, caused by an apicomplexan, that is introduced to humans by the bite of a hard body tick
toxoplasmosis
Outbreaks of this apicomplexan disease have been associated with fecal-contaminated imported raspberries, and also fresh greens and drinking water
cryptosporidiosis
Toxoplasmosis includes all the following except
intrauterine infectious are generally mild with very little damage to fetal tissues.
Symptoms of cryptosporidiosis include
headache, sweats, vomiting, severe abdominal cramps, and diarrhea.
Parasitic helminthes have the following characteristics except
have developmental forms that include cysts
Which is mismatched?
roundworm - trematode
Ascaris lumbricoides
All of the choices are correct (is an intestinal roundworm, spreads to humans by ingestion of Ascaris eggs in food, larvae penetrate into lymphatics and capillaries around intestines, larvae migrate to the pharynx, get swallowed and return to intestines to mature)
Enterobius vermicularis is
an intestinal worm that easily contaminates fingers and fomites.
Hookworms
All of the choices are correct (include Necator americanus, include Ancylostoma duodenale, have filariform larvae in soil that get transmitted into bare feet, have oral cutting plates by which they anchor to the intestines)
Strongyloides stercoralis
immunosuppressed patients can die from disseminated disease.
Trichinosis includes all the following except
All of the choices are correct (encysted larvae get ingested, associated with undercooked pork or bear meat, migrate from intestines to blood and various body tissues, coiled larvae encyst in skeletal muscle)
Elephantiasis includes all the following except
helminth is transmitted by black fly vectors.
River blindness is
a disease in which worms can invade the eyes.
Schistosomiasis involves
All of the choices are correct (a blood fluke, eggs from humans enter water and develop into miracidium, snails allow development into cercaria, cercaria enter hair follicles and pass to the blood and then the liver)
Fasciola hepatica is a
liver fluke.
All of the following pertain to tapeworms except
one proglottid segment will have either female or male reproductive organs.
Which is mismatched?
Echinococcus granulosus - poultry
The form lacking a free flagella in the developmental stage of a hemoflagellate is called the
amastigote.
All of the following will kill Giardia except
chlorine in typical drinking water.
Which of the following is not an effective way to minimize human contact with parasitic helminths?
These are all effective ways.
Which is not correct about trichinosis?
Only a few cases occur each year in the U.S.
Which parasite is carried by Cyclops, an arthropod commonly found in still water?
Dracunculus medinesis
Pregnant women should never change cat litter due to the risk of contracting
toxoplasmosis.
Which is not correct about kala azar?
Chemotherapy with chloroquine is usually effective.
The usual definitive host for Echinococcus granulosus is
dogs.
The larval forms of certain Taenia species, which typically infest muscles of mammalian intermediate hosts is also called a
cysticerci.
Trichinella spiralis is a/an _________ that invades the __________.
roundworm, intestine
Infection occurs when
pathogens enter and multiply in body tissues.
All infectious diseases
are caused by microorganisms or their products.
Endogenous infectious agents arise from microbes that are
the patient's own normal flora.
All of the following genera are considered resident flora of skin sites except
Escherichia.
Resident flora of the intestines include
None of the above (Streptococcus, Haemophilus, Staphylococcus)
The chemical found in tears and saliva that hydrolyzes the peptidoglycan in certain bacterial cell walls is
lysozyme.
The body region where a ciliary escalator helps to sweep microbes trapped in mucus away from that body site is the
respiratory tract.
Virulence factors include
All of the above (capsules, exotoxin, exoenzymes, endotoxin)
Someone who inconspicuously harbors a pathogen and spreads it to others is a
carrier.
An animal, such as an arthropod, that transmits a pathogen from one host to another is a
vector.
Which of the following is an example of vertical transmission?
a mother transmitting larva of roundworm to her fetus
A laboratory technologist splashed a blood specimen onto his face, eyes, nose, and mouth. This specimen was from an HIV positive patient. If this blood exposure leads to HIV infection in the technologist, the transmission route is
vehicle
The dried residues of fine droplets from mucus or saliva that harbor and transmit pathogen are
droplet nuclei.
Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are
biological vectors.
The ability of a fungus to grow as a yeast or a mold depending on its environmental temperature is called
dimorphism.
The routes of entry for most fungi into the body are
respiratory and cutaneous.
Amphotericin B, nystatin, and the imidazoles are all
antifungal drugs.
All of the following are dimorphic, true fungal pathogens except
Candida.
The terms used for the four levels of fungal infection include the following except
bloodborne.
Characteristics of Histoplasma capsulatum include
it grows in moist soil, rich in nitrogen from bird and bat guano.
The highest incidence of histoplasmosis in the United States occurs in the
East and Midwest.
Which is incorrect about histoplasmosis?
chronic cases have symptoms similar to tuberculosis
All of the following pertain to coccidioidomycosis except
the pathogen grows best in soil with bird and bat guano.
Blastomyces dermatitidis
favors forest soil, high in organic matter.
Paracoccidioides is
endemic to regions of Central and South America.
Which is incorrect about Sporothrix schenckii?
causes superficial cutaneous infection
Chromoblastomycosis and phaeohyphomycosis are
caused by saprobes with dark-pigmented mycelia and spores.
Mycetoma is
a subcutaneous infection that looks like a tumor.
Dermatophytoses are
All of the choices are correct (fungal infections of the skin, hair, and nails, also called ringworm, also called tineas, often time-consuming to eradicate completely)
Microsporum, Trichophyton, and Epidermophyton
reservoirs are humans, animals, and soils.
All of the following pertain to Candida albicans except
has a large capsule.
Candidiasis includes
All of the choices are correct (intertriginous infection of skin sites, vulvovaginal infection, oral cavity and esophageal infections, skin and nail infections)
Cryptococcus neoformans has the following characteristics except
commonly found in the human mouth, intestines, and genitalia
Cryptococcosis can include
All of the choices are correct (pulmonary infection, septicemia, meningitis, bone infection)
Oral thrush is caused by
Candida albicans.
This opportunist is the most frequent cause of life-threatening pneumonia in AIDS patients:
Pneumocystis (carinii) jiroveci
Aspergillosis includes all the following except
there are no effective drugs to treat the infection.
Serious mycoses treated with amphotericin B include all the following except
Pneumocystis pneumonia.
Decaying vegetation, such as piles of leaves and compost heaps, allows growth and transmission of
Aspergillus.
This organism commonly contaminates grains, corn, and peanuts and produces a potent mycotoxin called aflatoxin:
Aspergillus flavis
Pneumocystis (carinii) jiroveci
All of the choices are correct (has protozoan and fungal characteristics, lacks ergosterol in its plasma membrane, is an obligate parasite, causes serious infection in elderly, premature infants, and AIDS patients)
Ergotism is caused by
ingesting alkaloids from Claviceps purpurea on rye plants.
Menthol and camphor (VicksTM) are effective treatments against
ringworm.
All of the following areas are subject to intertriginous infections except
chest.
Which of the following is a rare mycosis caused by a mold commonly found in soil, in dairy products and on the human body?
sporotrichosis
All of the following are fungal allergies except
thrush.
Which of the following is incorrect about Sporotrichosis?
It is also known as Valley fever.
The primary portal of entry for fungal infections is
the respiratory tract.
Which antifungal drug inhibits cell division of the fungus?
griseofulvin
Which of the following are likely to predispose patients to fungal infections?
All of the choices are correct (cancer, AIDS, tuberculosis, malnutrition)
Alternative names for Blastomyces dermatitidis include
Gilchrist's disease.
Which is incorrect about chromoblastomycosis?
treatment is with pentamidine
Acanthamoeba differs from Naegleria fowleri in that only Acanthamoeba
enters typically through broken skin or the conjunctiva.