Infection and Host Resistance Flashcards
association between two (or more) species. Meaning “living together,”
Symbiosis
in which both members of the association
living together benefit from the relationship
mutualism
One organism benefits while the host is harmed
PARASITISM
Include bacteria, viruses, protozoa, fungi, and helminths
Parasites
Cause minimal harm to the host to maintain their own survival
Successful parasites
One species benefits while the other is neither harmed nor benefited
COMMENSALISM
Microbes occupying space prevent harmful microbes from colonizing, indirectly benefiting the host
Microbial competition
A situation where both species harm each other without
benefiting
Antagonism
Microorganisms are present on surfaces, objects, or body tissues
Contamination
The multiplication of parasitic organisms within or on a host’s body
Infection
Refers to the presence of larger parasites like worms or arthropods on the body
Infestation
A disturbance in health that occurs when an infection disrupts the
normal functioning of the body
Disease
Some infections cause no observable effect on the host
Infection without disease
Commensals cause no harm; parasites can invade tissues
Commensals vs. parasites
Occurs when the infection results in observable health disturbances, with effects ranging from mild to severe
Disease from infection
Characterized by changes in the host that interfere with normal function
Illness
Examples include a common cold where symptoms resolve without lasting effects
Reversible disease
Examples include untreated trachoma leading to
permanent vision impairment or untreated streptococcal infections causing irreversible heart or kidney damage
Irreversible disease
Caused by Mycobacterium tuberculosis
Tuberculosis
Caused by Streptococcus pyogenes (Group A Streptococcus)
Strep Throat
Caused by Vibrio cholerae
Cholera
Common bacterial agents include Streptococcus pneumoniae and Haemophilus influenzae
Pneumonia
Caused by Borrelia burgdorferi (transmitted by ticks)
Lyme Disease
Caused by Clostridium tetani
Tetanus
Caused by Neisseria gonorrhoeae
Gonorrhea
Caused by Treponema pallidum
Syphilis
Commonly caused by Escherichia coli (E. coli)
Urinary Tract Infections
CLASSIFICATION OF HOSTS
- Definitive
- Intermediate
- Paratenic
- Reservoir
Parasites’ relationship with the host
- Obligate
- Facultative
- Incidental/accidental
- Intermittent/temporary
- Permanent
Caused by Plasmodium species (e.g., Plasmodium falciparum, P. vivax), transmitted by mosquitoes
Malaria
Caused by Giardia lamblia (affects the intestines)
Giardiasis
Caused by Entamoeba histolytica (intestinal infection, often resulting in diarrhea).
Amoebiasis
Caused by Toxoplasma gondii (often transmitted by cats or contaminated food)
Toxoplasmosis
Caused by Leishmania species, transmitted by sandflies.
Leishmaniasis
Caused by Trypanosoma brucei, transmitted by the tsetse fly
Trypanosomiasis (Sleeping Sickness)
Caused by Trypanosoma cruzi, transmitted by the triatomine bug (kissing bug)
Chagas Disease
