Chap. 13 Microbe-Human Interactions

Disease

When the cumulative effects of an infection damage or disrupt tissues and organs, the pathologic state that results is known as a(n) _______.

Hemolysins

_______ are a class of bacterial exotoxin that disrupts the cell membrane of red blood cells (and some other cells too).

Antitoxins

_______ are antibodies generated to fight a specific toxin.

Toxinoses

_______ are diseases that are caused primarily by microbial toxins.

Pathogen

A microbe whose relationship with its host is parasitic and results in infection and disease is termed a _______.

Polymicrobial

A mixed infection is also known as a _______ disease.

Semen

A number of agents involved in sexually transmitted infections leave the host in vaginal discharge or _______.

Fecal

Many intestinal pathogens leave the body through the feces, otherwise known as the _______ route.

Necrosis

Accumulated damage by pathogens can lead to cell and tissue death, a condition called _______.

Contagious

If the disease is highly communicable, especially through direct contact, the disease is said to be _______.

Localized

In a _______ infection, the microbe enters the body and remains confined to a specific tissue.

Acute

Infections that come on rapidly, with severe but short-lived effects are called _______ infections.

Chronic

Infections that progress and persist over a long period of time are called _______ infections.

Nosocomial

Infectious diseases that are acquired or develop during a hospital stay are known as _______ infections.

Convalescent

Recuperating patients without symptoms are considered _______ carriers when they continue to shed viable microbes and convey the infection to others.

Normal Biota

Resident Biota: The Human as a Habitat -Cell for cell, microbes on the human body outnumber human cells at least ten to one. The large and mixed collection of microbes adapted to the body has been variously called the _______________.

Period of Invasion

The period during a clinical infection when the infectious agent multiplies at high levels, exhibits its greatest toxicity, and becomes well established in the target tissues.

Incubation Period

The period from the initial contact with an infectious agent to the appearance of the first symptoms.

Droplets

Tiny particles of liquid released into the air by a cough or sneeze form aerosols or _______ that can spread the infectious agent to other people.

Noncommunicable

A _______ infectious disease does not arise through transmission of the infectious agent from host to host.

Incidence

Disease _______ measures the number of new cases over a certain time period. Also called the morbidity rate.

Systemic

Endotoxin differs from exotoxins in having a variety of _______ effects on tissues and organs.

Lipopolysaccharide (LPS)

Endotoxins are actually a chemical called _______, which is part of the outer membrane of gram negative cell walls.

Gram Negative

Endotoxins are shed only by _______ bacteria.

High

Endotoxins are toxic to humans mostly in _______ doses.

Small Proteins

Exotoxins are generally made of _______.

Gram Positive

Exotoxins are produced mainly by _______ bacteria.

Mortality

The _______ rate measures the total number of deaths in a population due to a certain disease.

Endogenous

____________ infections- those caused by biota that are already present in the body. Can occur when the host has a compromised immune system or if the normal biota is introduced to a site that was previously sterile.

Infectious Disease

the disruption of a tissue or organ caused by microbes or their products

Infection

pathogenic microorganisms penetrate the host defenses, enter the tissues, and multiply.

Pneumonia

...

Focal

A _______ infection is said to exist when the infectious agent breaks loose from a local infection and is carried into other tissues.

Toxin

A _______ is a specific chemical product of microbes, plants, and some animals that is poisonous to other organisms.

Toxoid

A _______ is an inactivated toxin used in a vaccine.

Fomite

A _______ is an inanimate object that harbors and transmits pathogens. (doorknobs, telephones, needles)

Sign

A _______ is any objective evidence of disease as noted by an observer.

Symptom

A _______ is the subjective evidence of disease as sensed by the patient.

Biological

A _______ vector participates in a pathogen's life cycle, serving as a site which it can multiply or complete its life cycle.

Communicable

A disease is _______ when an infected host can transmit the infectious agent to another host and establish infection in that host.

Chronic

A person harboring a persistent infectious agent may or may not shed it during the latent stage. If it is shed, such persons are _______ carriers who serve as sources of infection for the rest of the population.

Passive

A person who mechanically transfers a pathogen without ever being infected by it is termed a _______ carrier.

Prodromal Period

A short period of mild symptoms occurring at the end of the period of incubation. It indicates the onset of disease.

Exotoxin

A toxin molecule secreted by a living bacterial cell into the infected tissues is called a(n) _______.

Endotoxin

A toxin that is not actively secreted but is shed from the outer membrane of a bacterial cell is called a(n) _______.

Latency

After the initial symptoms in certain chronic infectious diseases, the infectious agent retreats into a dormant state called _______.

Exogenous

An _______ infectious agent originates from a source outside the body (the environment or another person or animal).

Zoonosis

An infection indigenous to animals but naturally transmissible to humans is called a _______.

Mixed

An infection is not always caused by a single microbe. In a _______ infection, several agents establish themselves simultaneously at the infection site.

Pathogenicity

An organism's potential to cause infection or disease is called ______________. Divided into two groups called true pathogens and oppertunistic pathogens.

Virulence Factor

Any characteristic or structure of a microbe that contributes to its virulence is called a _______.

Convalescent

As a patient begins to respond to the infection, the symptoms decline - sometimes dramatically sometimes slowly. During the recovery that follows, called the _______ period, the patient's strength and health gradually return owing to the healing nature of the immune response.

Portal of Entry

Becoming Established- Step 1: Microbe enters the tissues of the body by a ______________. Usually a cutaneous or membranous boundary. Normally the same anatomical regions that support normal biota. Source of infectious agent: Exogenous and Endogenous.

Reportable

By law, certain _______ or notifiable diseases must be reported to authorities; others are reported on a voluntary basis.

Pathologic

Capable of inducing physical damage on the host.

Urine

Certain pathogens that infect the kidney are discharged in the _______.

Minute

Exotoxins are toxic to humans in _______ amounts.

Cell Membrane

Exotoxins generally effect cells by damaging the _______ and initiating lysis or by disrupting intracellular function.

Infectious Dose (ID)

For most agents, infection will proceed only if a minimum number, called the _______ ,is present.

Prevalence

In epidemiology, _______ is the fraction of a population having a specific disease at a given time.

Incidence

In epidemiology, _______ is the fraction of a population the contracts a disease during a specific time.

Sporadic

In epidemiology, a disease is said to be _______ if it occurs only occassionaly in a population.

Greater Virulence

In general, microorganisms with smaller infectious doses have _______.

Ligands

In the process of adhesion, the surface molecules on a pathogen, called adhesins or _______, bind specifically to complementary surface receptors on cells of certain host tissues.

Subclinical

Infections in which the host does not manifest the disease are known as asymptomatic or _______.

Microbial Antagonism

Many times bacterial biota benefit the human host by preventing the overgrowth of harmful microorganisms: ____________- the generally antagonistic effect "good" microbes have against intruder microorganisms.

Phagocytes

Microbes that are not established in a normal biota relationship in a particular body site in a host are likely to encounter resistance from host defenses when first entering, especially from certain white blood cells called _______.

Exoenzymes

Microorganisms either inflict direct damage on hosts through the use of _______ or toxins, or they cause damage indirectly when their presence causes an excessive or inappropriate host response.

Respiratory Tracts

Mucus, sputum, nasal drainage, and other moist secretions are the media of escape for the pathogens that infect the lower or upper _______.

Bacteriocins

Normal microbiota protect the host by occupying niches that pathogens might occupy, producing acids, and producing _______.

15%

Nosocomial infections affect anywhere from 5% to _______ of all hospital patients.

Weaken Host Defenses Against Infection

Old age, extreme youth, genetic or acquired defects in immunity, surgery, organ transplants, underlying diseases, chemotherapy, immunosuppressive drugs, physical and mental stress, and other infections are all factors that _______.

Pneumonia

Pathogens that are inhaled into the lower regions of the respiratory tract (bronchioles and lungs) can cause _______.

Carrier

Persons or animals with frank symptomatic infection are obvious sources of infection, but a _______ is, by definition, an individual who inconspicuously shelters a pathogen and spreads it to others without any notice.

Opportunistic

Pseudomonas species and Candida albicans are examples of _______ pathogens.

Lesions

Skin _______ and their exudates can serve as portals of exit in warts, fungal infections, boils, herpes simplex, smallpox, and syphilis.

Sequelae

Some diseases leave _______ in the form of long-term or permanent damage to tissues or organs.

Leukocidins

Species of both Streptococcus and Staphylococcus produce _______, substances that are toxic to white blood cells.

Continumm

The Human Host Contact, Infection, Disease- A ___________ Body surfaces are constantly exposed to microbes. Inevitably leads to infection: pathogenic microorganisms penetrate the host defenses, enter the tissues, and multiply. Pathologic state that results when the infection damages or disrupts tissues and organs is disease. Infectious disease: the disruption of a tissue or organ caused by microbes or their products.

Infection

The Progress of an _____________: Pathogen: a microbe whose relationship with its host is parasitic and results in infection and disease.Type and severity of infection depend on pathogenicity of the organism and the condition of its host.

Respiratory Tract

The _______ is the portal of entry for the greatest number of pathogens. Streptococcal sore throat, Meningitis, Diphtheria, Whooping cough, Influenza, Measles, Mumps, Rubella, Chickenpox, Common cold, Bacteria and fungi causing pneumonia.

Reservoir

The _______ is the primary habitat in the natural world from which a pathogen originates. Often it is a human or animal host but may also be through soil, water, or plants.

Prevalence

The _______ of a disease is the total number of existing cases with respect to the entire population. Often reported as the percentage of the population having a particular disease at any given time.

Source

The _______ of an infection is the individual or object from which an infection is actually acquired.

Urogenital

The _______ tract is the portal of entry for many pathogens that are contracted by sexual means. Sexually transmitted diseases (STDs) account for and estimated 4% of infections worldwide, with approximately 13 million new cases occuring in the US each year. They enter skin or mucosa of penis, external genitalia, vagina, cervix, and urethra. Some can penetrate an unbroken surface. Examples are: Syphilis, Gonorrhea, Genital warts, Chlamydia, and Herpes.

Septicemia

The clinical term for blood infection, _______, refers to a general state in which microorganisms are multiplying in the blood and are present in large numbers.

Keratin

The epidermis acts as an effective physical barrier against pathogens due to the tightly packed cell structure and the presence of the protective protein _______.

True (Primary)

The influenza virus, plague bacillus, and malarial protozoan are all examples of ______ pathogens.

Ciliary Escalator

The mechanical defenses of the lungs include the mucous membranes and the _______.

Coughing and Sneezing

The most effective means of releasing secretions from the lower and upper respiratory tracts are _______, although they can also be released during talking and laughing.

Colonization

The process by which microbes (which become normal biota) become implanted on body surfaces is known as _______.

Vector

The term _______ is used by epidemiologists to indicate a live animal that transmits an infectious agent from one host to another.

Horizontal

The term _______ means the disease is spread through a population from one infected person to another.

Vertical

The term _______ signifies transmission from parent to offspring via the ovum, sperm, placenta, or milk.

Vehicle

The term _______ specifies any inanimate material commonly used by humans that can transmit infectious agents. (food, water, blood, serum, fomites)

Condition of the Host

The type and severity of infection depends both on the pathogenicity of the organism and the _______.

Coagulase

The virulence factor _______ is an enzyme that acts to coagulate fibrinogen.

Collagenase

The virulence factor _______ is an enzyme that hydrolyzes collagen.

Hyaluronidase

The virulence factor _______ is an enzyme that hydrolyzes hyaluronic acid.

IgA Proteases

The virulence factors known as _______ are enzymes that destroy IgA antibodies.

Kinases

The virulence factors known as _______ are enzymes that digests fibrin clots.

Intoxications

Toxinoses caused by the ingestion of toxins are called _______.

Toxemias

Toxinoses in which the toxin is spread by the blood from the site of infection are called _______.

Syndrome

When a disease can be identified or defined by a certain complex of signs and symptoms, it is termed a _______.

Systemic

When an infection spreads to several sites and tissue fluids, usually in the bloodstream, it is called a _______ infection.

Secondary

When an initial, or primary, infection is complicated by another infection caused by a different microbe, the second infection is termed a _______ infection.

Bacteremia

When small numbers of bacteria or viruses are found in the blood, the correct terminology is _______ or viremia, which means that these microbes are present in the blood but are not necessarily multiplying.

Portal of Exit

With few exception, pathogens depart from the host by a specific avenue known as the _______.

Probiotics

_______ are live microbes either applied or ingested into the body, intended to exert a beneficial effect.

Asymptomatic

_______ carriers are infected but show no symptoms, seeming apparently healthy.

Incubating

_______ carriers spread the infectious agent during the incubation period.

Antiphagocytic

_______ factors are a type of virulence factor used by some pathogens to avoid phagocytes.

Epidemiology

_______ involves the study of the frequency and distribution of disease and other health-related factors in defined populations.

Adhesion

_______ is a process by which microbes gain a more stable foothold oh host tissues.

Toxigenicity

_______ is the ability of a pathogen to produce a toxin.

Phagocytes

_______ ordinarily engulf and destroy pathogens by means of enzymes and antimicrobial chemicals.

True (Primary)

_______ pathogens are capable of causing disease in healthy persons with normal immune defenses.

Opportunistic

_______ pathogens cause disease when the host's immune defenses are compromised or when they become established in a part of the body that is not natural to them.

Adhesion

_______ to host tissues is almost always a prerequisite for causing disease since the body has so many mechanisms for flushing microbes and foreign materials from its tissues.

Mechanical

_______ vectors are not necessary to the life cycle of an infectious agent and merely transport it iwthout being infected.

Infectious

__________ Agents that Enter the Skin: Nicks, abrasions, and punctures. Intact skin is very tough- few microbes can penetrate. Some create their own passageways using digestive enzymes or bites. Examples are Staphylococcus aureus, Streptococcus pyogenes, and Neisseria gonorrhoeae.

Acquiring

__________ Resident Biota: The body provides a wide range of habitats and supports a wide range of microbes

Biota

__________ can fluctuate with general health, age, variations in diet, hygiene, hormones, and drug therapy. Many times bacterial biota benefit the human host by preventing the overgrowth of harmful microorganisms: microbial antagonism Hosts with compromised immune systems could be infected by their own biota Endogenous infections: caused by biota that are already present in the body.

Virulence

____________- The degree of pathogenicity. This microbe is determined by its ability to establish itself in the host and cause damage. Different healthy individual share widely va rying responses to the same microorganism: hosts evolve.