Chapter 13 – Microbe–Human Interactions: Health and Disease

80 English fill-in-the-blank flashcards covering definitions, processes, and examples from Chapter 13 of Microbiology: A Systems Approach, 7th Edition.

Infection is a condition in which pathogenic microorganisms __ host defenses, enter tissues, and multiply.

penetrate

Disease is any __ from health resulting from cumulative effects of infection.

deviation

Normal biota is also known as resident or __ biota.

indigenous

A human plus all of its resident microbiota is called a __.

holobiont

Microbes inhabiting humans contain approximately – million protein-encoding genes.

8–20

The Human Microbiome Project showed that we harbor viruses infecting both human cells and cells of our resident __.

biota

Definitively known sites of normal microbiota include skin and adjacent __ membranes.

mucous

The _ respiratory tract (lungs) is now thought to harbor at least some normal microbiota.

lower

The antagonistic effect “good” microbes exert against intruders is called microbial __.

antagonism

Host defenses are especially weak in the very young and the very __.

old

Endogenous infections can occur when normal biota enters a body site that was previously __.

sterile

Human breast milk contains around __ species of bacteria.

600

Approximately 4 % of people carry Staphylococcus __ on their skin.

aureus

Opportunistic pathogens cause disease when host defenses are __.

compromised

Biosafety Level 1 organisms are not generally considered __.

pathogens

Biosafety Level 4 laboratories handle agents that are highly __.

virulent

Virulence is indicated by a microbe’s ability to establish itself in the host and cause __.

damage

Microbes with a smaller infectious dose have greater __.

virulence

A host’s genetics, exposure history, and overall __ affect susceptibility.

health

Influenza followed by bacterial pneumonia exemplifies a __ infection.

polymicrobial

Most portals of entry involve the skin or __ membranes.

mucous

An infectious agent that originates outside the body is termed __.

exogenous

Nicks, abrasions, and punctures allow pathogens to enter the __.

skin

How deeply a particle is inhaled depends on the __ of the particle.

size

Sexually transmitted infections account for about _ % of infections worldwide.

4

In TORCH infections, the “R” stands for __.

rubella

Adhesion depends on specific binding between molecules on both host and __.

pathogen

Bacterial chemical communication crucial for infection establishment is called __ sensing.

quorum

White blood cells that engulf pathogens are called __.

phagocytes

Structures that help pathogens avoid being eaten by phagocytes are __ factors.

antiphagocytic

The exoenzyme __ digests the protective coating of mucus.

mucinase

Lipopolysaccharide (LPS) released from gram-negative bacteria functions as an __.

endotoxin

Exotoxins are typically toxic in extremely __ amounts.

small

Unlike exotoxins, endotoxins are heat __.

stable

The earliest sign of many infections is __ of tissues.

inflammation

An abnormally high white blood cell count is termed __.

leukocytosis

The presence of multiplying microbes in the blood is called __.

septicemia

An infection that produces no noticeable symptoms is __ (subclinical).

asymptomatic

Pathogens leaving via coughing or sneezing exit through the __ tract.

respiratory

Irritation of the intestines often leads to diarrhea, expelling pathogens in __ matter.

fecal

A dormant state in which an infectious agent can reactivate later is called __.

latency

Long-term or permanent damage that remains after an infection is called a __.

sequela

The time between contact and first symptoms is the __ period.

incubation

The stage when the pathogen exhibits its greatest virulence is the __ phase.

acute

The primary natural habitat of a pathogen is termed its __.

reservoir

An infected individual who shows no symptoms is an __ carrier.

asymptomatic

A recovering but still infectious patient is a __ carrier.

convalescent

An arthropod that only transports a pathogen without being infected is a __ vector.

mechanical

A disease naturally found in animals but transmissible to humans is a __.

zoonosis

Spread of an infection from one person to another in the same generation is __ transmission.

horizontal

Transmission from parent to offspring is termed __ transmission.

vertical

An inanimate object that harbors and transmits pathogens is a __.

fomite

Dried microscopic residues of mucus and saliva are called __ nuclei.

droplet

Koch’s postulates require cultivation of the suspected pathogen in __ culture.

pure

Molecular Koch’s postulates focus on linking specific __ to pathogenicity.

genes

During child-bearing years, the dominant vaginal microbiota belongs to the genus __.

Lactobacillus

The healthy urinary tract also contains abundant __ species.

Lactobacillus

More than a dozen species of the genus __ colonize the oral cavity.

Streptococcus

Fecal microbiota are dominated by anaerobes such as the genus __.

Bacteroides

About 30 % of individuals carry Staphylococcus aureus in their __.

nose

Intact skin is a tough barrier that most microbes cannot __.

penetrate

Capsules and slime layers help bacteria resist __ by immune cells.

phagocytosis

The CDC classification of pathogen-handling risk is known as __ levels.

biosafety

Perinatal transmission occurs as the baby passes through the __.

birth canal

Toxins that can be inactivated to create toxoids are typically __.

exotoxins

Pathogen-induced alterations of host gene expression without DNA mutation are __ changes.

epigenetic

The patient recovery period in which symptoms decline is the __ stage.

convalescent

__ are subjective indications of disease felt by the patient.

Symptoms

An infection confined to a single tissue site is a __ infection.

localized

An infection involving multiple species of microbes is a __ infection.

mixed

A disease that appears suddenly and runs its course quickly is an __ infection.

acute

Walled-off collections of pus within tissues are known as __.

abscesses

Normal biota causing disease after entering a sterile site results in an __ infection.

endogenous

Pathogens capable of causing disease in healthy individuals are called __ pathogens.

true

The degree of pathogenicity of a microbe is called its __.

virulence

Diseases that do not arise from host-to-host transmission are __.

noncommunicable

The process by which microbes attach to host tissues is known as __.

adhesion

The fungal genus commonly found on human skin and mucosa is __.

Candida

Fimbriae, capsules, and viral spikes enable microbial __ to host cells.

attachment

When infection spreads via the bloodstream to multiple sites it is called a __ infection.

systemic