exam 3

which term refers to the study of the geographic distribution of disease and its transmission.

epidemiology

tetanus, which is caused by Clostridium tetani, is an example of which type of disease?

sporadic

Malarial disease in brazil is an example of which type of disease?

endemic

Robert Koch was the first to conclusively determine the causative agent of what disease

anthrax

what most specifically describes a notifiable disease?

any disease of public health importance

what is not a notifiable disease?

MRSA because it is so common and isn’t severe.

John snow developed a detailed map (the “ghost map” to investigate the etiology of what disease?

cholera

Which of the following is not an example of evidence used by John Snow to determine that

cholera was being transmitted by water in London in the 1800s?

A. a high frequency of cholera cases located near a water pump on Broad Street

B. beer workers not contracting cholera because they drank beer rather than water

C. microscopic examination of water

D. waste and sewage being dumped into the Thames River

C. microscopic examination of water

Which researcher required that surgeons should use a 5% carbolic acid solution to clean surgical tools as a way to prevent the spread of disease?

Joseph Lister

which type of studies gathers data from past cases to study present-day cases?

retrospective studies

how long does rhinovirus survive outside physiological fluids

less than a day

mary mallon, aka Typhoid Mary, was which type of carrier

asymptomatic

who traced the typhoid outbreak of 1900-1915 to mary Mallon?

george soper

Listeria monocytogenes, the causative agent of listeriosis, can pass through the blood-

placenta barrier to infect a fetus. This type of transmission to the fetus is what

vertical direct contact

sexually transmitted diseases between sexually active partners are most commonly transmitted by what method?

horizontal direct method

which of the following is not a fomite

1. catheter

2. nurse

3. scalpel

4. syringe

nurse

tuberculosis is typically transmitted via which of vthe following

1. air

2. food

3. sexual activity

4. water

air

a fruit fly lands on cow feces and then flies over to a bowl of watermelon being surved at a farm picnic. the fruit fly in this example is which of the following

1. biological vector

2. fomite

3. mechanical vector

4. vehicle

mechanical

which agency monitors notifiable diseases in the United States

CDC- centers for disease control and prevention

SARS first occured in _____, before becoming an _______ disease.

china, pandemic

what is the transmission mechanism for west nile virus

vector

the tsetse fly transmits what disease

african sleeping sickness

Which of the following is true about modern emerging diseases?

A. Malaria is an example of an emerging disease.

B. They are diseases that increase in frequency after a period of decline.

C. They are diseases that the WHO has classified as being poorly understood.

D. They occur in both developing and developed countries.

D. they occur in both developing and developed countries

Which of the following statements about quarantine is false?

A. Patients may be released from quarantine if preventive treatment can be administered.

B. Public health authorities can quarantine patients for any diseases.

C. Quarantine facilities can be equipped with special air-handling methods such as HEPA

filters.

D. Quarantine times depend on the incubation period of the disease.

b. public health authorities can quarantine patients for any diseases

The prevalence of HIV is generally higher than its incidence

true

etiology is the study of the transmission of diseases

false

all etiologic agents are pathogens

false

nosocomial infections can be acquired in hospital settings

true

in the 1800s, nosocomial diseases were prevalent

true

in experimental epidemoiological studies, study subjects are manipulated in some manner

true

humans can be reservoirs for pathogens

true

an individuals with HPV who has genital wart can transmit HPV to their partner via kissing on the lips

false

The WHO only monitors the prevalence of infectious diseases around the world

false

Match the outbreak to its proper description.

A. endemic

B. epidemic

C. pandemic

D. sporadic

i. a disease occurs relatively rarely, without a geographic focus

ii. a disease produces more cases vthan expected withkn a short time in a localized area

iii. a disease occurs at a relatively constant and often low level within a population

iv. a disease increases in frequency worldwide.

a. iii

b. ii

c. iv

d. i

a. common-source spread

b. continuous-source spread

c. intermittent-source spread

d. point-source spread

e. propagated spread

i. transmitted from a single source to all individuals infected

ii. transmitted from a common source that operates for longer than the incubation time for a pathogen

iii. occurs through direct or indirect person to person contact

iv. transmitted from a common source that operates for less than the incubation time of a pathogen

v. transmitted from a common source that operates sporadically

a. i

b. ii

c. v

d. iv

e. iii

Match the pathogen to the disease it causes.

A. Borrelia burgdorferi

B. Plasmodium falciparum

C. Rickettsia rickettsii

E. Yersinia pestis

i. african sleeping disease

ii. lyme disease

iii. malaria

iv. plague

v. rocky mountain spotted fever

a. ii

b. iii

c. v

d. i

e. iv

Of 100,000 individuals exposed to a particular bacterial pathogen, 500 develop disease. Of the 500 individuals who develop the disease, 100 die. The morbidity rate is ________ cases per 100,000 people.

500

Of 100,000 individuals exposed to a particular bacterial pathogen, 500 develop disease. Of the 500 individuals who develop the disease, 100 die. The mortality rate is ________ per 100,000 people.

100

John snow’s work on cholera showed that a water pump on broad street served as a ________ for the spread of infectious disease.

common source

_____ epidemiological studies are one in which data are gathered from study participants through measurements

observational

A health-care provider who does not have signs or symptoms of disease and is not infected but transmits a pathogen from one patient to another is said to be a(n) ________ carrier.

passive

ransmission of pathogens via water, food, and/or air is known as ________ transmission.

vehicle

What does the field of epidemiology cover?

epidemiology is the study of infectious disease distribution, timing, and transmission

morbidity is dependent upon what two aspects of a disease

prevalence and incidence

what is the difference between morbidity and mortality

morbidity refers to the state of being diseased, whereas mortality refers to death

what is a cross-sectional observational study?

A cross-sectional study compares individuals affected by a disease or condition at a single point in time with those unaffected at the same point in time.

what is a double-blind study?

A study in which neither the participants nor the researchers know what treatment (if any) was given.

Which of the following is not an example of a fomite?

1. catheter

2. doorknob

3. mosquitoes

4. towels

3. mosquitoes

Bacteria is most commonly reproduced using what method?

binary fission

which structure separates new daughter cells in binary fission

the division septum

what is another term for generation time

doubling time

what best describes culture density

the number of cells per unit volume

what is the correct order of phases of growth in the growth curve of a batch culture

lag phase —→ log phase —→ stationary phase —→ death/decline phase

what is not a common way bacteria divides?

sporulation

what is the term for free-living bacteria

planktonic

what is not a reactive oxygen species

atmospheric oxygen

which microbial pathogen has an unusually long doubling time?

mycobacterium leprae

the initial cells added to a batch culture are called what

the inoculum

what best describes bacterial growth during the log phase of the growth curve

exponential

what best defines the term persisters

cells with relatively slow metabolic rates that survive longer than others during the death phase and can cause chronic infections

what type of system is used to maintain bacteria in a relatively constant environment, allowing them to stay in the log phase of growth?

chemostat

what is an indirect method of measuring numbers of bacterial cells

turbidity measurements

what best describes why extracellular polymeric substances are important?

they are components of a biofilm secreted by the microbes present

Which of the following is not a common step in preparing a pour plate to make a count of microbial numbers?

A. A serial dilution is performed.

B. Bacteria are spread across the agar, using a sterile spreader.

C. Bacteria are mixed with warm agar and poured onto a Petri plate, then swirled.

D. The sample is allowed to grow, then colonies are counted.

B. bacteria are spread across the agar, using a sterile spreader

what media is commonly used to determine the oxygen requirements of a bacteria species

thioglycolate medium

what best describes how a microaerophile would grow in a thioglycolate tube culture?

a short distance below the top of the medium, but not at the top

A candle jar is used to grow what type of bacteria

capnophiles

what is the most common category of bacteria

neutrophiles

human pathogens are generally which type of microbe

mesophiles

food spoilage is caused by which microbe

psychtrotophs

what type of microbes thrive in the great salt lake

extreme halophiles

what range of the electromagnetic spectrum is considered photosynthetically active radiation

from visible light to near infrared

in batch culture, how long does the log phase of the bacterial growth curve appear

linear on a semi-log scale

what best describes the enzymes of extreme alkaliphiles

they have relatively high isoelectric points

what best describes the cell membranes of microbes that thrive at low temperatures

they have relatively high amounts of unsaturated fatty acids

if you grow two species of bacteria on mannitol salt agar to determine which can ferment mannitol, and you know both species an grow on the medium, what tyep of medium is the agar

differential

what pigments are especially useful at great depths, where less light penetrates

fucoxanthin and phycobilins

what microbes use light energy to pump hydrogen and sodium

halobacterium

Which of the following is true of using a Petroff-Hausser chamber to do a direct cell count?

A. Identical squares, all the same size, are etched into the slide.

B. If the sample was diluted, then the concentration must be corrected accordingly.

C. It is not necessary to know the volume of the sample added to the slide.

D. The chamber does not resemble a hemocytometer.

b. if the sample was diluted, then the concentration must be corrected accordingly

what would be the best choice for distinguishing living and dead bacteria in a cell count?

primary and secondary fluorescent stains

generation time in prokaryotes refers to the amount of time required for the doubling of the population through a single round of binary fission

true

fungi can generally thrive in drier environments than can bacteria

true

some halotolerant microbes are important causes of food poisoning

true

HEPA filters (a filter that traps 99.97% of airborne particles like dust, pollen, and smoke) are required for which biological safety level (BSL)

BSL 4

From a clinical setting, aseptic technique is carried out to do what?

prevent contamination in living tissue

the autoclave uses what mechanism for sterilization

pressure and temperature

autoclaves are designed to kill what following heat-resistant microbes?

endospores

what action would be most clearly considered bacteriostatic rather than bactericidal?

placing a bacterial culture in the -80C freezer

microbial death follows what type of trend

logarithmic

what is the standard conditions for an autoclave

121C, 15 psi, 20 minutes

what is not a milkborne pathogen?

yersinia pestis

for appropriate food storage in refridgeratiors, the temp sholuld be set to no higher than what

7C

how does pascalization control microbial growth

by denaturing proteins

X-rays and gamma rays are examples of what radiation

ionizing radiation

Ultraviolet light is an example of what type of radiation

nonionizing radiation

liquid growth media that contain antibiotics should be sterilized using what method

membrane filtration

what method of microbial control does not rely on denaturing proteins and the integrity of the cell membrane

lyophilization

phenolic compounds can be found naturally in what group of organisms

plants

what best describes how heavy metals can control microbial growth

by binding to sulfur containing amino acids

what is argyria

a buildup of silver in the body resulting in blue-gray skin