Micro Exam 2

Secondary infection

Infection that occurs after the primary infection weakens the body's defenses

Mechanical transmission

Passive transport on body parts

Kinases

Enzymes that break down protein and blood clots

Immune system recognition

Sometimes immune system can recognize capsules and produce antibodies

Pathology

The scientific study of disease

Etiology

Cause of disease

Pathogenesis

The way a disease develops and how it affects the body (structural and functional changes)

Infection

The invasion or colonization of the body by pathogenic microorganisms

Disease

An abnormal state; when an infection results in a change in health

Signs

Objective changes in body function that can be measured, such as fever and lesions

Syndrome

A collective group of signs and/or symptoms that accompany some disease

Infectious

A pathogenic organism capable of producing an infection

Communicable

A disease that can be transmitted from person to person

Noncommunicable

A disease that is not spread between hosts and must be introduced to the body some other way

Fomite

Objects or materials likely to carry infection, such as clothes and doorknobs

Acute disease

Develops rapidly and lasts a short time

Subacute disease

Lasts longer than an acute disease but is not considered chronic

Convalescence

Patient recovers, body returns to its prediseased state

Focal infection

When a local infection spreads but is still confined to specific areas of the body

Viremia

Viruses in the blood

R0 (r-naught)

The average number of people who will contract a disease from one infected individual

Zoonotic disease

A disease that has jumped from a non-human animal to humans

Airborne

Droplets of dust that travel more than 1m circulating in the air

Foodborne

Pathogens transferred from one food to another

Siderophores

Proteins that bind iron better than host cells, allowing pathogenic microbes to deplete host iron

Biofilm enzyme production

Organisms may produce certain enzymes only in specific biofilms

Invasions

Produced by bacteria to control the cytoskeleton and penetrate from cell to cell

Symptoms

Subjective changes in body function experienced by the patient but not directly observable

Contagious

A disease that is transmitted easily from person to person

Chronic disease

Develops slowly and continues or reoccurs for a long period

Latent Disease

Diseases such as varicella zoster and herpes simplex

Incubation Period

Time between initial infection and appearance of signs/symptoms

Prodromal period

Early, mild signs/symptoms as disease develops

Period of illness

Most severe disease transmission can occur

Period of decline

Signs/symptoms diminish

Local infection

Microbes limited to a small area of the body

Systemic infection

Generalized infection where microbes are spread throughout the body

Sepsis

Toxic inflammatory condition that occurs when microbes spread beyond their focus of infection

Septicemia

Pathogens enter the blood and spread throughout the body

Bacteremia

Bacteria in the blood

Toxemia

Toxins produced by pathogens enter the bloodstream

Primary infection

Acute infection, initial illness

Subclinical infection

Infections that don't cause any noticeable illness

Healthcare-Associated Infections (HAIs)

Infections most common in patients undergoing invasive procedures

Epidemiology

The science that studies when and where disease occurs and how they are transmitted in populations

Epidemic

Sudden spreading of a disease over a wide but isolated area

Pandemic

Epidemic that spreads worldwide

Endemic disease

A disease that is consistently present in a particular region

Incidence

Number of new cases of an infection within a specified period

Prevalence

Percentage of total cases of infected individuals within a particular population

Morbidity

Percentage of infected people who die as a result of infection

Case fatality ratio (CFR)

Percentage of people with symptoms who die as a result of infection

Herd Immunity

A point at which a disease has difficulty spreading through a population

Reservoir

The environment or host where a pathogen typically lives and multiplies

Vector

A living organism that carries a disease-causing agent from an infected host to a new host

Vector-borne disease

Disease that is transmitted via a vector

Direct Contact

Transmission from person to person

Congenital

Transmission from mother to fetus/newborn

Indirect Contact

Transmission through fomites

Droplet

Mucus droplets spread through coughing, sneezing, and laughing

Waterborne

Spread by contaminated water

Fecal-oral transmission

Transfer through microbes via waterborne, foodborne, or indirect contact

Biological transmission

Pathogens spread through bites

Pathogenicity

The ability of the microbe to cause disease in a host

Virulence

How severe the disease a microbe can cause

Main Portals

Mucous membranes, skin, and parenteral routes

Virulence factors

Factors affecting bacterial pathogenicity

Adherence

Attachment methods of bacteria and viruses to host cells

Bacteria adherence methods

Pili, fimbriae, glycocalyx, slime layers, and biofilms

Viruses adherence methods

Spike proteins

Adhesins

Surface proteins on bacterial cells that connect to host cell receptors

Ligands

Surface receptors on host tissues that bind to a receptor

Biofilms

Another method of adherence that is resistant to disinfectants and antibiotics

Capsules

Prevent phagocytosis so immune cells struggle to engulf and destroy microbes

Coagulases

Enzymes that form blood clots to camouflage from the immune system

Hyaluronidase

Enzyme that breaks down connective tissue, preventing healing of infected wounds

Collageneae

Enzyme that specifically breaks down collagen

Proteases

Enzymes that can destroy antibodies

Damaging host cells

Penetrating host cells using enzymes or structures for motility

Toxins

Most damage is done by these substances

Iron

The most common nutrient needed by pathogens to survive

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What is the definition of sterilization?

The process of killing or removing all microbes, including endospores.

How does disinfection differ from sterilization?

Disinfection reduces pathogenic organisms to a non-threatening level but does not necessarily kill all microbes or endospores.

What is the primary difference between a disinfectant and an antiseptic?

Disinfectants are for inanimate objects, while antiseptics are safe for use on living tissues.

What is the microbial death curve?

The observation that antimicrobials kill a constant percentage of bacteria over time.

Name three environmental factors that influence the effectiveness of microbial control.

Temperature, pH, and the presence of organic material like dirt or grease.

What are the two primary mechanisms by which microbial control agents kill cells?

Damaging the cell membrane to increase permeability or damaging proteins and nucleic acids.

What is the main advantage of autoclaving over boiling?

Autoclaving uses increased pressure to raise the boiling point, making it effective against endospores.

How does pasteurization affect food products?

It kills most microbes while maintaining the food's nutritional integrity and molecular structure.

What is the primary use of filtration in a laboratory setting?

Sterilizing heat-sensitive liquids and gases by trapping microbes in a membrane.

How does ionizing radiation kill microbes?

It produces hydroxyl radicals that damage DNA and other cellular components.

What is the mechanism of nonionizing radiation (UV light)?

It creates thymine dimers in DNA, causing replication errors.

Why was Triclosan banned from antibacterial soaps?

Its widespread use contributed to increased antibiotic resistance.

What are the limitations of alcohols as disinfectants?

They are not effective against endospores or non-enveloped viruses.

What is the function of quaternary ammonium compounds?

They act as surface-active agents that disrupt plasma membranes, primarily against gram-positive bacteria.

Which liquid chemical agent is capable of true sterilization?

Glutaraldehyde.

What are gaseous chemostrilants used for?

Sterilizing heat-sensitive materials by cross-linking nucleic acids and proteins.

What is plasma in the context of microbial control?

An excited gas state that uses free radicals to destroy microbes on heat-sensitive equipment.

Why are gram-negative bacteria generally more resistant to biocides?

Due to the presence of lipopolysaccharides in their outer membrane.