Ch. 14 Flashcards
Two organisms live together in a close partnership
Symbiotic
Obligatory, dependent symbiotic relationship; both members benefit
Mutualism
Symbiotic relationship where one organism benefits, other is not harmed or benefited
Commensalism
Symbiotic relationship where one organism is dependent and benefits (parasite), other organism (host) is harmed
Parasitism
Organisms are free-living; relationships not required for survival
Non-symbiotic
Non-symbiotic relationship where members cooperate to produce a result that none of them could do alone
Synergism
Non-symbiotic relationship where actions of one organism affect the success of survival of others in the same community (competition).
Antagonism
What is a contaminant?
An impurity/undesirable material or organism
Presence of bacteria on a body surface without causing disease; invasion of new habitat by a new species; presence and multiplication of microorganisms without tissue invasion or damage-colonies develop when a bacterial fell begins reproducing
Colonization
Condition where pathogenic microorganisms penetrate host defenses, enter tissues, and multiply
Infection
What is a pathologic state?
When cumulative effects of infection cause damage; disruption of tissues and organs; results in disease
What is an infectious disease?
Disruption of tissues/organs caused by microbes or their products
Large and diverse collection of microbes living in and in the body; aka resident/indigenous it normal flora; include bacteria,fungi, protozoa, and viruses
Normal biota
What have differences in the gut microbiome been associated with?
Heart disease, asthma, autism, rheumatoid arthritis, even thoughts moods mental illness
What were the results of the human microbiome project?
22,000 protein encoding genes in human cells
8 million in microbes that inhabit humans
We have lots microbes in places we used to think sterile
All healthy people harbor potentially dangerous pathogens (but in low #’s)
What are benefits of normal biota?
Influence development of organs; prevent overgrowth of harmful microorganisms
The general antagonistic effect that good microbes have against intruder microorganisms. Microbes in a steady, established relationship are unlikely to be displaced by incoming microbes
Microbial antagonism
Infections caused by biota already in the body
Endogenous
A microbe whose relationship with its host is parasitic
Pathogen
An organism’s potential to cause infection or disease
Pathogenicity
True vs opportunistic pathogens
True-can cause disease in healthy people with normal immune defenses
Opportunistic-cause disease when host’s defenses are compromised/when they become established in a part of the body that is not natural to them
What is virulence?
Severity of disease caused by microorganism
To reduce the virulence of a pathogenic bacterium or virus by passing it through a non-native host or by long-term subculture
Attenuate
Secreted by pathogenic bacteria, fungi, protozoa, worms. Break down and inflict damage on tissues. Dissolve host’s defense barriers and promote spread of microbes into deeper tissues
Exoenzymes
Specific chemical product of microbes, plants, and some animals that is poisonous to other organisms
Toxin
Differences between exotoxins and endotoxins?
Exotoxins: secreted by living bacterial cell to infected tissues; many types; ex: hemolysin
Endotoxins: not actively secreted; made of phospholipid-polysaccharide complex; shed from outer membrane; only found in gram-negative bacteria
Example of an exotoxins; Any biological agent that is capable of destroying red blood cells and causing release of hemoglobin
Hemolysin
Process by which microbes gain a more stable foothold on host tissues; dependent on binding between specific molecules on both the host and pathogen because pathogen limited to cells/organisms it can bind to; once attached, pathogen can invade body compartments
Adhesion
When does a secondary infection occur?
Occurs when a primary infection is complicated by another infection caused by a different microbe
Acute vs chronic infections
Acute-happen rapidly, short-lived effects
Chronic-progress and persist over long period of time
Increase in the level of white blood cells
Leukocytosis
Decrease in the level of white blood cells
Leukopenia
General stare in which microbes are multiplying in the blood and are present in large numbers
Septicemia
Small numbers of bacteria are present in the blood but not multiplying
Bacteremia
Presence of viruses in the blood, whether or not they are actively multiplying
Viremia
Infections that go unnoticed
Asymptomatic, subclinical, or inapparent- host is infected but does not manifest the disease; patient experiences no symptoms;
Time from initial contact with infectious agent to the appearance of first symptoms
Incubation period
When earliest notable symptoms of infection appear
Prodromal period
Infectious agent multiplied at high levels and exhibits greatest virulence
Period of invasion
Patient responds to infection and symptoms decline
Convalescent stage
Dormant state of an infectious agent; microbe can periodically become active and provide recurrent disease
Latency
Long-term or permanent damage to organs and tissues
Sequelae
Three methods of control of communicable and contagious diseases
Isolation, quarantine, vector control (like mosquitos)
4 categories of disease duration
1) acute
2) chronic
3) sub-acute (gradual onset, almost always fatal)
4) latent (remain in host after symptoms disappear)
What is the etiologic agent?
Causative agent
Developed standard for determining causation of disease and he determined causative agent of anthrax
Robert Koch
A series of proofs that established the principal criteria for etiologic studies
Koch’s postulates
What were Koch’s 4 postulates?
1) find evidence of a particular microbe in every case of a disease
2) isolate the microbe from an infected subject and cultivate it artificially in lab
3) inoculate a susceptible healthy subject with the lab isolate and observe the resulting disease
4) re-isolate the agent from this subject
