Class 3 Flashcards
All living creatures share 2 basic objectives in life which are?
1) survival
2) reproduction
All living creatures share 2 basic objectives in life:
1) survival
2) reproduction
to satisfy these goals, organisms must do what?
Extract from the environment essential nutrients.
-can benefit both organisms or produce harmful &
potentially lethal consequences.
Consequences of these invasions are called _______________.
infectious diseases
What is a host?
any organism capable of supporting nutritional & physical growth requirements of another organism.
What is infectivity?
ability of organism to enter, multiply & survive in host
What is infection?
presence & multiplication within host that results in injury to host
What is colonization?
act of establishing a presence within a host
T/F All interactions between microorganisms and humans are detrimental?
False - NOT all interactions between microorganisms and humans are detrimental
What is microflora?
multitude of non-harmful bacteria that inhabit internal & external exposed surfaces of human body.
Microflora can be found in what?
• Skin
• Nose/Pharynx
• Mouth
• Colon/Rectum
• Vagina/Distal Urethra/Perineum
What is commensalism?
Colonizing organism benefits & host is NOT adversely affected by it
What is Mutualism?
Colonizing organism & host both derive benefits
What is Parasitic?
Colonizing organism benefits & host gains nothing or sustains injury
Infectious disease can vary in severity and can be due to
______________________ and ______________________________.
• host health
• virtulence of the organism
What is Virulence?
Disease producing potential of invading organism.
__________________ are an example of a highly virulent organism and are rarely found in the host when there is no disease.
Pathogens
What are Saprophytes?
Harmless, free living organisms that obtain nutrition from dead or decaying organic materials in environment.
What is an Opportunistic Pathogen?
An organism which is capable of producing an infectious disease only when health & immunity of host have been severely compromised.
What are Prions?
• protein particles that lack any kind of demonstrable genetic material.
• mutated forms of normal host protein.
• may affect other normal proteins & alter them.
• aggregate in brain & form plaques.
• have been identified in number of incurable &
transmissible degenerative neurological diseases
• defective protein may be inherited.
• Transmissible degenerative neurological diseases are
all characterized by slowly progressive, non inflammatory neuronal degeneration, leading to loss of coordination (ataxia), dementia & death ranging from months to years.
• Current antimicrobial agents are useless against them
therefore treatment is palliative.
Prions have been identified in a number of incurable &
transmissible degenerative neurological diseases such
as?
• Creutzfeldt-Jakob disease
• Kuru
• Mad Cow disease
Rickettsia, Chlamydia, Coxiella, Mycoplasma are organisms that combine characteristics of ______________ and ______________.
viruses and bacteria
What is Rickettsiacecae?
- Live inside host cell since they rely on host cell for vitamins & nutrients
- Transmitted by insect vectors/bite of arthropod (fleas, ticks & lice)
- Produce number of potentially lethal diseases
Ex. Rocky Mountain Spotted Fever & Epidemic Typhus.
What is Chlamydiaceae?
• Scavenge intermediates of energy metabolism, like ATP.
• Transmitted directly between susceptible vertebrates
without intermediate arthropod host.
Ex. Sexually transmitted infection Chlamydia which can lead to pelvic inflammatory disease & sterility in women. Infants born to infected mothers can develop eye infections & pneumonia.
What is Coxiella?
• Infects variety of animals & in humans produces
illness often called Q fever, illness that presents with flu-like symptoms, & cause progress to become systemic
affecting heart, lungs, & GI.