December 2 Flashcards
Clostridium botulinum
Adult botulism: consumed food in which toxins have been produced by vegetative cells (Toxins are heat sensative)
Infant botulism: infants comsume food with endospores, vegetate in intestine, vegetative cells produce toxins inside intestines
*honey
Clostidium tetni
Toxin causes constant muscle contractions, no muscle relaxation(“lock jaw”) can break bones
Endospores are found in soil
Mycoplasmas
Cell wall-less
Gram positive
Very small
Intracellular parasites
Pleiomorphic
“fried egg look”
Actinobacter
Phylum of bacteria (related to gram positive)
Rod-shaped, usually aerobic
Harmless comensules (Mycobacteria are exceptions)
Many produce antibiotics and ferment dairy products
Corynebacterium
Gram positive
Aerobic
nonmotile rods
Snapping division- leads to V-shaped cell arrangements (pallisade arrangement)
Propionibacterium
Produce propionic acid through fermentation
Propionic acid gives swiss cheese its flavor
Anerobe
P. acnes acne in humans, feed on nutrients in our sebacious glands , flourish with a lot of oil, immune system attacks causing inflammation and puss
Streptomyces
Filamentous
Produce mycelia analogues to mycelia of fungus
approx. 500 species
Found in soil
Produce geosmins- responsible for “earthy” smell of soil
Strict aerobe
Secrete many extracellular enzymes
Approx. 50% produce antibiotics
Cyanobacteria
Closely related to Gram positive
oxygenic phototrophs
Many have gas vessicles- help maintain bouyancy to access light
Heterocysts: rounded enlarged cells, no photosystem II–cannot fix carbon dioxide, instead reduce N2 to NH3 in the herterocyst
Anaerobic–important for Nitrogen fixation, nitrogenase will not work around oxygen
Many produce toxins that can accumulate in larger fish
Gliding motility
Green Sulfur Bacteria
Chlorobium
anoxygenic phototroph
Nonmotile
Found in anoxic environment
H2S e- donor, use e- to oxidize to SO42-
Spirochetes
Gram negative
Motile, axial flagella–unique, wraps around cell, corkscrew through environment
Troponema pallium
