The skin is an effective barrier against invading microbes because

the outer layers are dead and covered in salt.

Normal skin microbiota are able to grow on the skin because of their resistance to

sebum and salt

An infection of a hair follicle at the base of an eyelid is called a

sty

One feature that differentiates Staphylococcus aureus from other staphylococci is its

production of both coagulase and beta-lactamase

Virulent strains of Staphylococcus aureus can resist penicillin because they produce

beta-lactamase

Which of the following is a complication that may result from a Streptococcus pyogenes skin infection?

erysipelas

Impetigo can be caused by

both Staphylococcus aureus and Streptococcus pyogenes

Staphylococcal scalded skin syndrome is caused by

exfoliative toxins

The common name for a furuncle is

a boil

Necrotizing fasciitis is caused by

both Streptococcus pyogenes and Staphylococcus aureus.

A specific wavelength of blue light can be used to treat

acne

Cat scratch disease is caused by

Bartonella henselae.

Anthrax derives its name from which of the following aspects of the disease?

the appearance of eschars on the skin

The resistance of Pseudomonas to a wide variety of antimicrobial drugs is due, in part, to its

ability to pump drugs out of the cell

Petechiae are subcutaneous hemorrhages associated with which of the following?

RMSF

Transovarian transmission is a process by which

an infected female vector transmits a pathogen to the eggs in its ovaries.

What is the pathogenic process underlying Rocky Mountain spotted fever?

damage to blood vessels

"Pox" is a term synonymous with which of the following?

a pustule

Smallpox was the first human disease to be

globally eradicated

Clostridium perfringens is a strict anaerobe that is a common environmental contaminant and
consequently of wounds due to its ability to

produce endospores

Acyclovir is a chemotherapeutic agent used to treat

herpes

Shingles, or herpes zoster, is caused by the same virus that causes

chickenpox

Common skin warts are the result of infection with

papillomaviruses

Some strains of Papillomavirus are oncogenic due to their ability to

integrate into the host cell DNA

Erythema infectiosum is also known as

fifth disease

Which of the following is an INCORRECT pairing?

herpes zoster : genital warts

Which of the following can cause birth defects?

rubella

Which of the following is becoming rarer as a result of childhood vaccinations?

subacute sclerosing panencephalitis

"Ringworm" is caused by

dermatophytes growing in the upper dead tissue layers of the skin.

Ultraviolet illumination is the quickest way to diagnose infections of which of the following?

Malassezia furfur

Sporotrichosis is more commonly known as

rose-gardener's disease.

A man is suffering severe foot pain in the area of what looks like a large wart. He reports he
has had the wart for some time, and the pain and swelling have developed slowly. A sample from
the lesion shows that the pus contains large cells that stain a golden brown color. The man is
likely suffering from

chromoblasomycosis.

A child complains of intensely itchy "pimples" on the hands and wrists. The lesions are small
inflamed streaks, but do not appear to contain pus. The child's condition may be the result of
infection with

Sarcoptes scabiei.

Which of the following forms of leishmaniasis is typically fatal?

visceral

A small puncture wound on a woman's arm has become swollen, hot to the touch, and
intensely painful. There is tissue necrosis, but it is not "gassy," and under the microscope Grampositive cocci in chains are present. Which of the following microbes is likely to be responsible?

Streptococcus pyogenes

A pigment produced by an opportunistic pathogen that contributes to tissue damage is

pyocyanin.

Which of the following is/are anti-phagocytic?

protein A, M protein, and leukocidin

Which of the following bacterial pathogens is an intracellular parasite?

Bartonella henselae

The rash described as "teardrops on rose petals" is characteristic of

chickenpox

A child has a rash on the face, arms, upper legs and torso that is splotchy, and intensifies
after being in the sun. The child does not complain of fever or itchiness. The signs and symptoms
are consistent with

fifth disease.

A sample from an abscess is stained and examined under the microscope. A Gram stain
appears uniformly pink, but a GMS (Gomori methenamine silver) stain reveals brownish
filaments in the sample. These findings suggest

phaeohyphomycosis

Clostridium perfringens causes necrotizing fasciitis.

FALSE

M protein is a virulence factor associated with group A streptococci.

TRUE

Humans are the only hosts of Rickettsia rickettsii

FALSE

Because they are common soil saprobes, dermatophytes are fungi that are not contagious in
humans.

FALSE

Chromoblastomycosis is rarely a severe disease and can be treated easily with appropriate
drugs

FALSE

Mucocutaneous leishmaniasis, also known as kala-azar, is fatal in 100% of untreated cases.

FALSE

Smallpox vaccination was originally discontinued in the 1980s because of adverse effects of
the vaccine.

TRUE

Herpesvirus infections can be controlled with chemotherapeutic agents.

TRUE

In pregnant women, roseola infection can result in teratogenic birth defects

FALSE

Pityriasis' characteristic appearance is the result of a fungal infection causing changes in the
production of melanin.

TRUE

Which of the following statements concerning viruses is FALSE?

Viruses enter a cell to complete the replication they have begun extracellularly

The outermost layer of a virion fulfills which of the following functions of the virus?

protection and recognition

During the intracellular state, a virus exists as

a nucleic acid.

Viruses are primarily classified according to their

type of nucleic acid.

Host specificity of a virus is due to

interactions between viral and cellular surface molecules.

Who was the first person to demonstrate the existence of viruses?

Ivanowsky

How are fungal viruses different from viruses that infect other organisms?

They have no extracellular state.

Which of the following infectious particles do NOT have protein in their structure?

viroids

Which of the following would NOT be found as a component of a bacteriophage?

envelope

Which of the following statements regarding virus taxonomy is true?

Some virus family names are derived from the name of an important member of the family.

Which of the following statements comparing virus classification and taxonomy of
organisms is true?

Genus and specific epithet are used in both classification systems

Put the following stages of a lytic replication cycle in order, from earliest to latest stages:
I. Synthesis
II. Assembly
III. Attachment
IV. Release
V. Entry

III, V, I, II, IV

Which of the following is associated with the attachment of a bacteriophage to a bacterial
cell?

random collisions, chemical attractions, and receptor specificity

The enzyme lysozyme is critical for which of the stages of a bacteriophage T4 infection
cycle?

entry and release

The phenomenon of transduction is associated with which of the stages of a bacteriophage
infection cycle?

assembly

Which of the following events occurs in the lytic cycle of bacteriophage T4 infection but
NOT in the lysogenic cycle?

digestion of host DNA

Why is lysogeny advantageous to a bacteriophage?

The genetic material of the bacteriophage can be passed on to future generations of cells.

Which of the following agents is capable of inducing conversion of a prophage back to a
lytic phage?

UV light and X rays

Zones of clearing in cell cultures that are the result of virus infection are called plaques.
Sometimes "cloudy plaques" are seen on bacterial cultures infected with bacteriophage. What
type of viral infection might cause this appearance?

lysogenic

Which of the following is matched INCORRECTLY?

adenovirus — membrane fusion

Reverse transcriptase is associated with which of the following?

retroviruses

The genome of which of the following types of animal virus can act directly as mRNA?

+ssRNA viruses

Which of the following types of animal virus requires RNA-dependent RNA transcriptase to
be replicated?

-ssRNA viruses

In contrast to most dsDNA animal viruses, the poxviruses replicate solely in the cytoplasm of
the host cell. This fact implies that the viral genome may encode

RNA-dependent RNA transcriptase.

Which of the following membranes can give rise to a viral envelope?

the nuclear and cytoplasmic membranes and the endoplasmic reticulum

The majority of cases of infant diarrhea are caused by what kind of virus?

dsRNA viruses

How is the HIV provirus different from a lambda phage prophage?

The HIV provirus is integrated permanently into the host cell's DNA.

Which of the following individuals discovered prions?

Prusiner

One mechanism by which viruses may cause cancer is to interrupt the genetic regulatory
sequences of repressor proteins. Which of the following types of viruses is most likely to be
involved in causing cancer by this mechanism?

retroviruses

Tumors invade other organs and tissues in a process called

metastasis

Plaque assays are used for

estimating the number of phages in a culture.

Diploid cell cultures and continuous cell cultures differ in which of the following ways?

longevity and source of cells

Viroids infect

plants.

How are prions different from all other known infectious agents?

They lack nucleic acid.

The infectious particles of fungi have RNA genomes and lack a capsid. They are therefore
similar to

viroids.

A lipid membrane is present

in both cells and viruses.

Double-stranded RNA genomes can be found

only in viruses

Cytoplasm is a characteristic of

cells only.

Proteins are present in

both cells and viruses.

Viruses are shed slowly and steadily during

persistent infection.

During __________, viruses remain dormant in a cell.

latency

Virus replication results in the death of the cell in a(n) __________ infection.

lytic

Virus infection results in cancer in the process of

oncogenesis

is a mechanism of release for enveloped viruses.

Budding

Viruses cause most human cancers.

FALSE

Most viruses cannot be seen by light microscopy.

TRUE

Protozoa are susceptible to viral attack.

TRUE

Many diseases of plants are caused by infectious RNA molecules lacking capsids.

TRUE

Bacteriophages are cheaper and easier to culture than animal viruses.

TRUE

Assembly of new viruses is a process that usually requires the direction of a variety of viral
and cellular enzymes

FALSE

Bacteriophage release is a gradual process in which small numbers are released at a time.

FALSE

Poxvirus is assembled in the cytoplasm of the cell instead of in the nucleus, as is the case for
the majority of dsDNA viruses.

TRUE

Transcription of RNA from RNA does not occur in uninfected cells.

TRUE

Virus vaccines are always cultured in embryonated chicken eggs

FALSE

Which of the following is NOT an example of symbiosis?

microbes crossing the placenta to the fetus

Mutualism is a relationship

that provides benefits for both members, sometimes to the point that one cannot live without
the other.

Figure 14.1 represents a Petri dish with a fungus (F), shown in darker gray, growing in the midst
of bacterial lawn (B), shown in light gray. Both microbes were from the same patient sample.
The relationship between the fungus and the bacteria would best be described as

commensal.

The bacterium Staphylococcus aureus is commonly found in the nasal cavity of healthy
people. If inhaled into the lungs, however, it may cause pneumonia. Staphylococcus aureus is
best described as

both resident microbiota and opportunistic pathogen.

Chagas' disease is transmitted by a bug with mouthparts that penetrate blood vessels. Which
type of exposure does this represent?

parenteral route

Symptoms are

subjective characteristics of a disease that only the patient can feel.

The close contact between newborns and family members allow them to become ________
with microbes that become established as their microbiota.

colonized

In which of the following do the mucous membranes serve as a portal of entry for disease?

A person rubs the eye with contaminated fingers and the pathogen is washed into the nasal
cavity by way of tears.

Which of the following statements regarding the demonstration of the etiology of disease is
FALSE?

The suspect agent must be the only potential pathogen present in disease cases.

Which of the following situations is NOT a way in which a baby acquires normal
microbiota?

Microbes cross the placenta during pregnancy.

Which of the following situations might cause normal microbiota to become opportunistic
pathogens?

treatment of a cancer patient with radiation

Which of the following is a fungus and is considered part of the normal human microbiome?

Candida

A toxin common to most Gram-negative bacteria is

lipid A.

Among the virulence factors produced by Staphylococcus aureus are hemolysin, coagulase,
hyaluronidase, and enterotoxin. Which of these factors contribute to the ability of S. aureus to
invade the body?

hyaluronidase

Which of the following stages of an infectious disease is the most severe?

the illness period

Which of the following is an example of vehicle transmission?

drinking contaminated water

Which of the following is considered a mechanical vector transmission?

cockroach transmission of Shigella

Which of the following is a sign of disease?

fever

Which of the following is a symptom of disease?

dizziness

Diseases that are induced by modern medical procedures are referred to as ________

iatrogenic

A syringe is used for multiple patients, one of whom has hepatitis B. The syringe is not
properly sterilized, resulting in possible ________ transmission.

indirect contact

A person is exposed to fungus and develops an infection. No one taking care of him/her
becomes ill, suggesting the infection is a ________ disease.

non-communicable

) In early spring 2009, the CDC reported several dozen cases of novel H1N1 influenza ("swine
flu") in the United States. By the end of the year millions of people had been infected. The
pattern of novel H1N1 cases in the United States represents a(n) ________ disease.

epidemic

The incidence of tuberculosis in the year 2000 in the United States was 12.43/100,000 cases.
This means

there were 12.43 new cases of tuberculosis for every 100,000 people in the United States in
the year 2000.

A strain of Neisseria gonorrhea has a mutation which has caused it to lose the ability to
produce fimbriae and become less virulent as a consequence. What function has this pathogen
lost?

the ability to adhere to cells of the body

Over 470,000 cases of cholera were reported in Haiti in the two years following the 2010
earthquake. Which of the following was the most likely mode of transmission

contaminated water

The person known to history as "Typhoid Mary" was identified by public health officials as a
source of typhoid fever, although she reported she had never had typhoid fever. Which of the
following is the most accurate description of her in this scenario?

both a human carrier and a reservoir

Aerosols may be involved in ________ transmission of pathogens.

droplet

Fomites are

inanimate objects involved in the indirect contact transmission of pathogens.

Koch's postulates were used to demonstrate the relationship between

Haemophilus influenzae and meningitis.

Which of the following diseases may be reduced by improved public sanitation measures?

cholera

Which of the following is the CORRECT sequence of a disease process?

incubation, prodromal period, illness, decline, convalescence

People who wash their hands frequently during cold season typically have fewer colds than
those who do not. This observation suggests cold viruses can be transmitted by

both direct contact and fomites

A patient developed a blood infection after a dental procedure which resulted in bleeding
gums. The patient has

a healthcare-associated infection (HAI).

Which of the following virulence factors directly contributes to severe inflammation?

lipid A

A pathogen is best described as

any microorganism that causes disease.

Microbes known as transient microbiota are

organisms that remain in the body for a short time.

Infectious diseases can be classified on the basis of

disease severity and duration, organ system affected or type of microbe.

Organisms that are resident microbiota are best described as

microorganisms that remain with the person throughout life.

A new influenza strain appears and is spreading rapidly. What measures might be taken by
public health agencies to stop the spread?

Educate the public, promote vaccination, and treat those who are infected

Commensalism is best described as a(n)

relationship between two organisms where only one member benefits.

The condition called parasitism is characterized as a(n)

relationship between two organisms where one member harms the other.

An axenic environment is one

that is free of microbes.

The condition known as microbial antagonism may be defined as

an unsuccessful microbial invasion due to the presence of pre-existing microbes

A reservoir is

a source of microbial contamination.

In commensalism, one member of the relationship harms the other.

FALSE

Normal microbiota may cause disease if conditions change in the bod

TRUE

A syndrome is a group of symptoms and signs that collectively characterize a particular
disease.

TRUE

All diseases go through the stages known as incubation period, prodromal period, and illness.

: FALSE

Microbial contamination always results in infection.

FALSE

Hepatitis C is an acute disease

: FALSE

Biofilms provide an alternative means for bacteria to attach to surfaces within the body.

TRUE

People in the incubation stage of a disease may be a reservoir of the agent.

TRUE

Koch's postulates can be applied to every infectious disease to identify its causative pathogen.

FALSE

All infections result in disease.

: FALSE