Chapter 14-15: Mechanisms Of Pathogenicity (part 1) Flashcards
What is pathogenicity?
The ability to cause disease
What is resident flora AKA normal flora?
Microbes that colonize a host without causing disease
T/F most areas of the body in contact with the outside environment harbor resident microbes
True
What are Transient microbiota?
Microbes that occupy the body for only a short time period, can last for days/weeks (come & go)
What are resident microbiota?
Microbes that become established (permanent aka normal flora)
Name some areas in the body that have resident flora
Skin, mouth, GI tract, external genitalia, and upper respiratory tract
What is a sterile site?
An area that is free of microorganisms
Sterile sites in the body include?
Heart, lungs, brain, bloodstream, and kidneys
What happens when sterile areas in the body are comprised?
Inflammation occurs in attempt to attack the invading microbes
What are the benefits of normal flora?
Helps prevent overgrowth of harmful microbes, helps digest food, and create an environment that may prevent infections and enhance host defenses
What must a pathogen do to cause disease in the host (HINT* getting in and out) ?
Pathogen enters portal of entry (skin) through # of invading microbes, adherence, multiplies, infects target, causes disease and goes out through portal of exit (coughing)
What is a virulence factor?
A characteristic or structure that contributes to the ability of a microbe to cause disease
What are 3 examples of virulence factors?
Endotoxins, capsules and spores
What is a endogenous infection?
An infection that occurs when normal flora is introduced to a site that was previously sterile
What can disrupt our normal flora?
Antibiotics, pH, dietary changes, and disease
What is a pathogen?
Infectious agent
What is the difference between infection vs disease?
Infections is a condition in which pathogenic microbes penetrate host defenses, enter tissues and multiply. A disease is when an infection causes damage or disruption to the tissues and organs (host health is altered)
What is a true pathogen?
Capable of causing disease in healthy individuals with normal immune defenses (Does not require a weaken host)
What is an opportunistic pathogen?
Cause disease when the host defenses are compromised
What are some factors that increase susceptibility to opportunistic pathogens?
Old age, extreme youth, genetic defects in immunity, surgery, organ disease, and physical/mental stress
What are Exogenous agents?
Originate from source outside the body
What are endogenous agents?
Already exist on or in the body (normal flora)
What is an infectious dose (ID)?
The minimum number of microbes needed to produce infection
The ability to attach to cell via fimbriae,cilia, and adhesive slime and capsules
Adherence
