keywords:
Bookmark and Share



Front Back
Definition: Microbiology
Study of microorganisms & their effects on the environ.
Definition: Epidemiology
Study of health & disease states in a population
Def: Intoxication
Ingestion of a toxic agent
Def: Infestation
an organism living on the body surface
Def: Infection
an organism transmitted to a host
Def: Immunology
Study of human body immune response mechanisms (immunity, allergy, transplantation, cancer, immune dysfxn)
Def: Infectious disease
Pathologic state produced by microorganisms living in/on human body;

Causes direct damage, nutrient competition, etc
Symbiote
organisms living together for the benefit of both
Parasite
organisms living together at the expense of another
Pathogen
organism capable of causing detrimental effects in a normal host
Opportunistic pathogen
organism doesn't usually produce disease but can under certain circumstances
Carrier state
host harboring and transmitting potential pathogen
Environmental factors affecting human interaction w/ microorganisms
nutrients, oxygen, anti-microbial substances, physical barriers, pH, microenvironments
Sterile areas of the body
areas where microorganisms shouldn't be found;

Blood, lymph
non-sterile areas of body
most areas other than blood or lymph
Superkingdom: Eukaryote
(classification)
Kingdoms:

Plantae
Animalia
Fungi
Protista
animalia (kingdom)
includes:

parasitic worms, arthropods
fungi (kingdom)
includes: molds, yeast
branches of kingdom protista
Protozoa - protozoan parasites
Protomycota
Protophyta
Superkingdom: Prokaryotae
Kingdoms:

Monera - bacteria, rickettsia, chlamydia
mycoplasma
evidence for endosymbiont origin of mitochondria
- eukaryote cells still have endosymbiotic bacteria
- ribosomes of mito more like those of prokaryotes
- mito have own DNA (circular, like prok.)
- mito control their own division
- gene expression into mito similar to prok.
- energy prod. in inner membrane, like prok.
- some antibiotics that kill bacteria also affect mito (chloramphenicol)
outer mitochondrial membrane origin
a reminant of its cell wall
inner mitochondrial membrane origin
equivalent to a euk. cell membrane
typical prokaryote structure
May contain:
  • capsule - locate external to cell wall)
  • ribosomes
  • cytoplasm
  • cell wall
  • plasma membrane
  • nuclear area (non-membrane bound DNA)
  • plasmids - circular DNA
  • flagella
  • fimbriae - hair-like projections
  • plasma membrane
  • inclusions
selective toxicity
if you can find something poisonous to a prokaryote but not a euk. (or vice versa), you can limit infection
Clinical significance of prok. cell structure
- selective toxicity
- interfere w/ prok. cell structure to limit growth
- basis of antibiotic therapy
Structure/Fxn of Viruses
Structure: protective protein coat (capsid) surrounding genetic info (DNA or RNA, not both for same virus);

Requires host cell for replication;

Genetic info encodes for:
- replication enzymes/mechanism
- redirection of cellular fxn
- replication of protein coat
- replication of viral nucleic a.
infection/replication process of viruses
1. introduction of infecting virus
2. Attachment: virus attaches to receptor on host cell

- can only infect cells whose receptors will recognize attachement point on viruses capsid or envelope
3. Penetration: virus is introduced into host cell
4. Uncoating: capsid is shed
5. Replication: synth of viral mRNA, synth of viral protein for new capsid, synth of viral nucleic acid
6. Assembly: capsid form around DNA/RNA
7. Release: by budding (forms envelope) or cytosis (no envelope)
8. Virus infects another host cell
pathogenesis of viruses
Cause direct cellular damage (do not create toxic substances);

cause disfunction of host cell;

may cause immunological damage to infected host cell
non-enveloped DNA viruses
contain no external envelope;

ex. parvovirus, adenovirus
enveloped DNA viruses
contain DNA surrounded by a capsid & envelope;

ex. herpes virus, poxvirus
non-enveloped RNA viruses
RNA surrounded by a capsid only (no envelope);

ex. poliovirus, rotavirus
enveloped RNA viruses
RNA surrounded by capsid & envelope;

ex. retrovirus (HIV), paramyxovirus
resolving power
ability to differentiate 2 closely positioned points
effect of wavelength on resolving power
shorter wavelength = greater resolving power
dark field microscopy
visible light introduced @ an angle so only light refracted by specimen enters lens;

organism appears white agains a black field;

generally only used for treponema pallidum (syphillus)
bright field microscopy
visible light wavelengths;

organism dark against white-grey field

stains: simple, gram stain, negative stain
Phase-contrast/Nomarski interference microscopy
visible light introduced thru specimen out of phase or non-parallel;

variations in density of cell materials refract light differently
UV light / flourescent microscopy
use short wavelengths to improve RP and increase mag.;

use flourescent dyes that flouresce in specific WL of visible light
Transmission electron microscope
streams of electrons focused by electromagnets;

significant improvement in RP and mag;

requires lots of prep
scanning electron micro.
streams of electrons bounced of surface
viruses
- noncellular
- require host to replicate
- some have envelope
- virtually no self-contained enzymes (use host)
- reproduce by molecular replication
- variety of effects to host
- only grown in specific living cell
bacteria (eubacteria)
- prok. cell structure
- free-living as single of small group of cells
- some produce resistant endospores
- reprod. by sexual binary fission
- produce toxic substances
- can be grown in lab
mycobacteria
- prok. cell structure
- free-living (but capable of surviving in WBC)
- waxy material in cell wall make them resistant
- slow reprod. by binary fission
- do not produce toxic substances
- trigger immunologic damage in host
- slow growth in lab
rickettsia and chlamydia
- prok. cell structure
- obligate intracellular parasites
- dependent on host cell
- poor survival outside host
- transmitted by arthropod vector
- do not grow in lab
mycoplasma
- prok. cell structure
- lack bacterial cell wall
- reprod. by binary fission
- have sterols in cell mem.
- poor survival in environment
- produce inflamatory rxn in host
- can grow slowly in enriched lab media
fungi
- euk. cell structure
- free-living cells grow as single cells (yeast) or chains (molds)
- chitinous cell wall
- reprod. by budding/apical growth of filaments
- few pathogens
- generally don't prod. toxic substances
- may prod. asexual spores
- grown in lab as colonies or mycelia
protozoa
- euk cell structure
- lack cell wall but animal cell type of mem.
- free-living or intracellular parasites
- single cell organisms
- complex life cycles
- some transmitted by insects
- cannot be grown in lab
helminths
- euk cell structure
- multi-cell animal parasites
- flatworms & roundworms
- environmentally resistant ova
- compete for nutrients w/ host
- complex life cycle w/ sexual stages
- not grown in labs
arthropods
- euk cell structure
- ectoparasites (blood sucking)
- some transmit infectious viruses, bact., etc
- produce immunological damage
- produce toxic substances
x of y cards Next > >> >|