survey of organisms in microbiology. taxonomy of infectious agents and parasites kingdomsexample of...
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Survey of Organisms in Microbiology
Taxonomy of infectious agents and parasites
Kingdoms example of organisms included
Monera bacteria
Protista protists, protozoa
Fungi molds, yeasts
Animalia helminthes, arthropods
Non-living agents
Viruses vary by nucleic acid type, capsid and envelope
Prions vary by tertiary structure and AA sequence
Bacteria
Group Example Genus
Gram positive bacteria
High GC Mycobacterium
Low GC Bacillus
Proteobacteria
alpha Rickettsia
beta Bordetella
gamma Escerichia
delta
epsilon Helicobacter
Spirochaetes Borrelia
Other groups
Protists
Group Common name Example
Mastigophora flagellates Giardia
Apicomplexa sporozoans Plasmodium
Sarcodina amoebas Entamoeba
Ciliophora ciliates Balantidium
Deuteromycota- fungi imperfecta
Ascomycota- sac fungi
Although many are multicellular, some fungi (yeasts) are unicellular
Fungi
Flat worms (Platyhelminthes)
• Cestodes - tapeworms• Trematodes- flukes
Tapeworms (Cestodes)
Ingestion of meat
Ingestion of feces
Trematodes
feces
Ingestion of aquatic vegetation or penetration of larvae
Nematodes (round worms)
Some representatives of major groups
Hookworms –penetration
Pinworms-ingestion inhalation
Whipworms and Trichinella-ingetsion of meat
Ascaris worms- ingestion of feces
Guinea worms- ingestion of water and vector
Filarial worms-insect bite
Arthropods
Insects-flies, bugs, lice, fleas, roaches
Arachnids-ticks and mites
Crustaceans- barnacles, copepods
Note: some of the above are vectors, some are parasites, some are both
Diseases caused by arthropods
Arthropods:Insects
•Pediculosis- louse infestation with Pediculus humanis (body), P. capitis (head) or Pthirus pubis (crab louse)
•chigoe Tunga penetrans
InsectsSiphonaptera-fleasDiptera-flies
NematoceraCeratopogonidae-no-see-ums, sand gnatsCulicidae-mosquitoesPsychodidae-sand fliesSimuliidae-blackflies
BrachyceraTabanidae-horse and deer flies
CyclorrhaphaMuscidae-housefliesGlossinidae-tetse fliesMiscelaneous families-Botflies, blowflies, bottleflies
Hemiptera-bugsReduviidae-conenose (kissing) bugsCimicidae-bed bugs
DictyopteraBlattidae-roaches
Anoplura-sucking lice
Myiasis
Squirrel bot fly: Cuterebra emasculator
Fly maggots can be facultative or obligate parasites, the resulting diseases are collectively called myiasis
Artrhopods: Mites (including ticks)Arachnida
Acari
Ixodidae-hard ticks
Argasidae-soft ticks
Laelapidae-hematophagous mites
Dermanyssidae-hematophagous mites
Demodicidae-follicle mites
Trombiculidae-chiggers
Sarcoptidae-scabies mites Ticks
Ticks
Lone star tick
American dog tick
Black legged tick (deer tick)
• Ticks are important vectors• Some species also cause tick paralysis
Scabies mites
• Sarcoptes scabiei
Other Mites
Follicle mites Demodex spp.
Chiggers Eutrombicula alfreddugesi
Viruses
Classified by nucleic acid type
Divided into Orders (sometimes), Family, Genus, ad Species
Ex. Rhabdoviridae, Lissavirus, Rabies Virus
Viral nucleic acids
dsDNA
ssDNA
dsRNA
(+)RNA
(-)RNA
RNA viruses often carry RNA polymerase or reverse transcriptase
Prions
Infectious proteins
Normally found on surface of mammalian cells
Abnormal secondary and tertiary structures
Resistant to heat and radiation
Long ‘incubation’ period
Prion “replication”
Normal protein transformed from helices to beta pleated sheets