Transcript Fig. 16.3
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 Gram positive bacteria High GC Low GC Proteobacteria alpha beta gamma delta epsilon Spirochaetes Other groups Example Genus Mycobacterium Bacillus Rickettsia Bordetella Escerichia Helicobacter Borrelia Protists Group Common name Example Mastigophora flagellates Giardia Apicomplexa sporozoans Plasmodium Sarcodina amoebas Entamoeba Ciliophora ciliates Balantidium Fungi Deuteromycota- fungi imperfecta Ascomycota- sac fungi Although many are multicellular, some fungi (yeasts) are unicellular Flat worms (Platyhelminthes) • Cestodes - tapeworms • Trematodes- flukes Tapeworms (Cestodes) Ingestion of feces Ingestion of meat 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 Insects Siphonaptera-fleas Diptera-flies Nematocera Ceratopogonidae-no-see-ums, sand gnats Culicidae-mosquitoes Psychodidae-sand flies Simuliidae-blackflies Brachycera Tabanidae-horse and deer flies Cyclorrhapha Muscidae-houseflies Glossinidae-tetse flies Miscelaneous families-Botflies, blowflies, bottleflies Hemiptera-bugs Reduviidae-conenose (kissing) bugs Cimicidae-bed bugs Dictyoptera Blattidae-roaches Anoplura-sucking lice Myiasis Fly maggots can be facultative or obligate parasites, the resulting diseases are collectively called myiasis Squirrel bot fly: Cuterebra emasculator 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 • Ticks are important vectors • Some species also cause tick paralysis American dog tick Lone star tick Black legged tick (deer tick) 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