MICR 1113 Unit 4 Exam Review

The composition of the normal microbiota can change in response to

- Activities of the human host such as consuming food - Physiological variations within the host such as hormonal changes

A human baby will acquire normal microbiota from

- Contact with other humans - From ingested foods and from the environment - From passage through the birth canal

Disease that can be transmitted from one host to another, such as influenza, are __________ diseases

- Contagious - Communicable diseases

A woman still recovering from shingellosis diarrhea has a bowel movement but doesn't wash her hands afterward. She then shakes with another woman, who later touches her mouth with her fingers and develops shigellosis. This is an example of.........

- Direct contract - Fecal-Oral transmission

Transmission of pathogens via direct contact.......

- May be reduced by routine handwashing - Often involves organisms with a low infectious dose - Can be as simple as a handshake or as intimate as sexual intercourse

A healthcare-associated infection (HAI) is one acquired in a

- Urgent care facility - Doctor's office - Hospital - Long-term care facility

Patients with infectious diseases are often hospitalized and may inadvertently spread the disease are often hospitalized and may inadvertently spread the disease to others. This spread can be minimized via

- Use of disinfectants - Scrupulous cleaning

Hemolysin

An enzyme produced by some pathogens that lysis or break down red blood cells

Pandemic

An epidemic disease that occurs worldwide

The components of the adaptive defenses that protects against bacteria invading blood and other body fluids is

Antibodies

In diseases like tetanus and diphtheria, exotoxins can kill hosts before they can make protective ________________ to fight them off

Antibody

Interferon results in

Apoptosis of infected cells

Many sexually transmitted diseases are spread when an infected individual is unaware of his or her infection. These infections are

Asymptomatic

Kinase

Bacterial enzymes that break down fibrin and, thus, digest blood clots formed by the body to isolate an infection

Healthcare workers who are asymptomatic _______ of pathogens may not recognize that they pose a risk to patients until they are implicated in an outbreak

Carriers

The vast majority of microbes that live in and on humans beings......

Cause no harm

The spread of an infectious disease follows a series of steps called the

Chain of infection

When pathogens from one food are transferred to another, this is referred to as

Cross-contamination

Infectious diseases that are newly recognized or have recently increased in incidence are called

Emerging Infectious Diseases

The fungal disease histoplasmosis, which is constantly present in the Mississippi and Ohio River drainage area is what type of disease?

Endemic

Coagulase

Enzyme produced by several species of that facilitates its spread by coating bacterial with blood plasma protein so the immune system does not recognize it

Cholera, when it was reintroduced into Haiti in 2010 is what type of disease?

Epidemic

A number of Gram-positive and Gram-negative pathogens make ______, or proteins that have very specific damaging effects

Exotoxins

True or false: A localized infection is disseminated throughout the body. A good example of this is measles

False

True or false: Bacterial pathogens that invade the body through the skin have specialized adaptations that allow them to cut through he tough outer layers of the epidermis

False

Why must pathogens first adhere to host cells to initiate an infection?

First-line defenses are very effective in sweeping away microbes

An inanimate object such as a doorknob that can transmit infectious agents is called a

Formite

A disease is not likely to spread within a population if 90% or more of the individuals are immune to the disease agent. This type of immunity is called.......

Herd immunity

Transfer of a pathogen from your pet to you is an example of a ____________ transmission

Horizontal

People who are __________ are defined as having weaknesses of defects in their innate or adaptive immune responses

Immunocompromised

Fomite

Inanimate (non-loving) objects that can be used to transmit a disease

The _______ of a disease is the number of new cases in a given population over a specific time

Incidence

Malnurition, overcrowding, and fatigue _________ people's susceptibility to infectious disease

Increase

Use of a urinary catheter ________ the risk of developing a urinary tract infection

Increases

The time it takes before a pathogen begins to cause symptoms of disease is called the

Incubation period

Transfer of a pathogen from one host to another via an inanimate object is an example of ________ transmission

Indirect

Many hospitals employ an ________ control practitioner (ICP) whose role is to perform active surveillance of the types and numbers of infections that arise in the hospital

Infection

If a person hasn't been vaccinated and contracts a toxin-mediated disease, he or she could be treated by

Injection of an antitoxin, a suspension of exotoxin-neutralizing antibodies

Why have pathogens evolved mechanisms to evade immune responses?

Inside the body, they will be under attack by these responses. Evasion will allow them to survive

Droplet Transmission

Large droplets that generally fall to the ground within 1 meter release

Pathogenicity

Measurement of the ability of a microorganism to cause a disease

Opportunist

Micoorganisms that ordinarily do not cause disease in their normal habitat but can cause disease under special conditions especially if the host's health is compromised

Virulence factors are coded for by

Microbial genes

When a patient receives intravenous fluids, his or her own ____________ may gain access to the bloodstream, potentially leading to bacteremia

Microbiota

Transient Microbiota

Microorganisms that are present in or on the body for a short time, then disappear

Normal Microbiota (Flora)

Microorganisms that establish permanent colonies inside or on the body without producing disease

After gaining entry into an epithelial cell, Shigella species and Listeria monocytogenes use a novel mechanism involving host cell actin which allows them to

Move from one host cell to the other without leaving the cytoplasm of either cell

Most invasive pathogens enter the tissues via

Mucous membranes

Hospital-associated infectious, or ___________ infections, are a subset of healthcare-associated infections (HAIs) and refer to infections acquired while patients are receiving treatment in a hospital

Nosocomial

When people talk, sneeze, laugh, cough, and sing, they discharge microbes in small liquid droplets that evaporate, leaving behind airborne particles called droplet

Nuclei

A cluster of botulism causes arising from a group picnic is what type of disease?

Outbreak

A new type of influenza that is infecting large numbers of people on several continents is what type of disease?

Pandemic

Endotoxin

Part of the outer portion of the cell wall of gram-negative bacteria, released when the cell dies

A microbe capable of causing noticeable damage to the human body is called a

Pathogen

Airborne Transmission

Pathogen transmitted by droplets of saliva or mucous

By surviving within white blood cells called __________, some pathogens are able to hide from antibodies, control some aspects of the immune response, and be transported to other locations in the body

Phagocytes

If a pathogen has its reservoir in the nose of a human, and the human sneezes, the nose is considered to be the __________ for the pathogen

Portal of exit

Symbiosis

Refer to different organisms living together

The natural habitat of a pathogen, which might include humans, non-humans, or the environment, is called the _______ of infection

Reservoir

The single most important measure for preventing the spread of infectious disease is considered to be

Routine handwashing

Leukocidin

Substance produced by some pathogens that can destroy neutrophils and macrophages

Most exotoxins fall into three general categories that reflect their structure and general mechanism of action. These three categories are

Superantigens Membrane-damaging toxins A-B toxins

What are some factors that can lead an individual to become immunocompromised?

Surgery Wounds Cancer Malnutrition Alcohol or drug abuse

The intimate relationships between the microorganisms and the human body are an example of _______, meaning "living together"

Symbiosis

Unlike asymptomatic carriers, individuals with symptomatic infections are more likely to

Take precautions to avoid transmitting their illness to others

Virulence

The degree of pathogenicity for a specific microorganism

As with bacterial pathogenesis, damage due to viral infection is often due to

The host responses

Morbidity

The incidence or rate of disease in a population

The minimum number of a particular microbe required to cause disease is called

The infectious dose

To avoid destruction by the complement system, some microbes avoid the formation of

The membrane attack complex (MAC)

Bacteremia

The presence of bacteria in the bloodstream

Viremia

The presence of free viral particles in the blood

Toxemia

The presence of toxins circulating in the bloodstream

Case-Fatality Rate

The proportion of persons diagnosed with a specific disease who die from that disease

Epidemiology

The study of the distribution and causes of disease in populations

Exotoxin

Toxin produced by pathogenic bacteria and released into the surrounding environment

What microorganism may only take up residence in the body areas for temporary periods of time

Transient microbiota

True or false: Endotoxin can cause septic shock

True

True or false: Exotoxins can enter the body by person consuming preformed molecules contaminating food and water and by colonization of tissues with bacteria that then produce the molecules

True

Mutualism

Type of symbiosis that benefits both organisms

In addition to directed uptake, another method used by some pathogens to cross epithelial membranes in the intestine is

Uptake through specialized M cells in the intestines that usually sample contents of the lumen

____________ elicit production of these protective molecules before the exotoxin is released into the host's system

Vaccines

If an HIV-Infected pregnant woman transfers HIV to her fetus, this is an example of ___________ transmission

Vertical

Successful pathogens have multiple _______ factors that enable them to adhere to a host or penetrate host cells, avoid recognition or destruction by the immune system, and damage the host

Virulence

_________ factors are traits of a microbiota that specifically allow it to cause disease

Virulence

To avoid transmitting infectious agents from patients to patients, it is particularly important for healthcare personnel to............

Wash hands

Animals such as skunks, raccoons, and bats are reservoirs of the rabies virus. Therefore, rabies is considered _______ disease

Zoonoses

Diseases with a long incubation period can spread extensively before the first symptomatic case appear a. True b. False

a

Because of the widespread use of antimicrobial drugs in hospitals, many organisms causing noscomial infections have become resistant to these medications a. False b. True

b

The Centers for Disease Control and Prevention (CDC) focus on all of the following activities EXCEPT a. Publishing the MMWR b. Supporting infectious disease labs c. Researching infectious disease d. Collecting data on diseases affecting public health e. Primary patient care

e

Commensal

A symbiotic relationship where one of the organisms benefits and the other organism is unaffected

Reservoir of Infections

A continual source of a specific infectious organism

Endemic

A disease that is constantly present in a population at low levels

Sporadic

A disease that occurs only occasionally in a population

Nosocomial Infection

A hospital-acquired infection

In the process of directed uptake by cells,

A host cell is tricked into engulfing a pathogen, which infects the host cell

Cytopathic Effect

Detrimental changes in host cells due to being infected by a virus

In cases of ______ transmission, a pathogen is transmitted from one host to another by physical contact or respiratory droplets, for example, via a handshake, sexual contact, or sneezing on another

Direct

Zoonose

Disease that occurs primarily in wild and domestic animals, but can also be transmitted to humans

Pathogen

Disease-causing microorganism