Card Set Information

2012-11-01 10:23:47

Show Answers:

  1. List major characteristics used to classify and identify the following bacteria and list two examples for the 5 groups of Proteobacteria
    • Proteobacteria (general): most gram-negative chemoheteroprophic bacteria.  Largest taxonomic group.
    • Alphaproteobacteria: Capable of growth at very low levels of nutrients. N2 fixation in plants, plant and human pathogens.
    • Bartonella (human pathogens, can survive phagocytosis)
    • Rhizobium (infects roots of legumes and forms nodules for N2 fixation)
    • Betaproteobacteria: Often use H2, NH3, and CH4 as nutrient substances.  Several important pathogenic bacteria.
    • Thiobacillus (important in sulfur cycle, H2S->SO42-)
    • Zoogloea (slimy masses in aerobic sewage-treatment processes, essential)
    • Gammaproteobacteria: largest subgroup, great variety.
    • Pseudomonas (aerobic, gram negative, rods, motile by polar flagella, produces water soluble pigments, use nitrate as final electron acceptor, metabolically diverse)
    • Enterobacteriales (live in intestines, peritrichous flagella, facultative anaerobes, have fimbrae for attachment)
    • Deltaproteobacteria: includes bacteria that are predators of other bacteria, and bacteria that are important contributers to the Sulfur cycle
    • Bdellovibrio (preys on other bacteria, reproduces in and lyses host cell to release new cells)
    • Desulfovibrio (Sulfur-reducing bacteria, use S instead of O2 as final e- acceptor producing H2S)
    • Epsilonproteobacteria: slender gram negative rods that are helical or curved, both important genera are motile via flagella and microaerophilic
    • Campylobacter (single polar flagellum, C. jejuni is the leading cause of gastroenteritis)
    • Helicobacter (multiple flagella, has urease, causes peptic ulcers and stomach cancers)
  2. List major characteristics used to classify and identify the following bacteria and list two examples for two types of non-proteobacteria (gram negative)
    • Several physiologically and morphologically distinctive photosynthesizing bacteria.  Cyanobacteria produce oxygen during photosynthesis, and the green sulfur and green nonsulfur bacteria do not produce oxygen
    • Cyanobacteria: oxygenic photosynthesis.  Fix nitrogen with specialized cells (heterocysts).  Gliding motility. Purple and green sulfur bacteria, living in deep freshwater do not produce O2
    • Chlamydiae: intracellular pathogens that do not have peptidoglycan, STI/urethritis
  3. List major characteristics used to classify and identify the following bacteria and list two examples for non-proteobacteria (Gram positive)
    • Divided into 2 phyla, Firmicutes (low G+C ratios) and Actinobacteria (high G+C ratios).  Mycoplasmas are grouped with Firmicutes even though they do not have a cell wall. 
    • Firmicutes: important endospore forming bacteria (Clostridium, Bacillus), mycoplasma, Staphylococcus, Enterococcus, and Streptococcus
    • Clostridium (endospore-producing rods.  Obligate anaerobes.  Causes disease by production of neurotoxins)
    • Lactobacillus (lactic-acid producing, commercially used in production of saurkraut/pickles/yogurt, found on human body as normal flora)
    • Actinobacteria: highly pleomorphic, several important pathogenic genera (Mycobacterium), actinomycetes (star shape, resemble filamentous fungi),
    • Mycobacterium (Aerobic, non-endospore forming rods.  Mycolic acid in cell walls - acid fast stain, slow growth, pathogens for lepracy and tuberculosis)
    • Nocardia (Aerobic, soil bacterium, causes pulmonary infection, acid fast)
  4. List major characteristics used to classify and identify the following bacteria and list two examples for each Chlamydiae, Spirochaetes, Bacteriodetes
    • Chlamydiae: Do not contain peptidoglycan in their cell walls. Gram negative.  Cocci.  Do not require insects/ticks for transmission.  Pathogenic.  (eg Chlamydia and Chlamydophila)
    • Spirochaetes: Coiled morphology (metal spring), motility by endoflagella causing corkscrew rotation, found in human oral cavity (Treponema [syphillis], Borrelia [relapsing fever, lime disease])
    • Bacteriodetes: Anaerobic bacteria.  Gram negative.   Nonendospore forming.  (Bacteriodes [GI tract, can cause infections during surgery, nonmotile], Cytophaga [important in cellulose/chitin degredation -soil-  Gliding motility]
  5. Define the Domain Archaea, list characteristics that make them unique and list examples
    • Prokaryotes whose cell walls lack peptidoglycan (pseudomurein)
    • Highly diverse: morphology, reproduction, physiology, nutrition, extremophiles
    • Sulfolobus: hyperthermophile found in hyperthermal vents
    • Methanobacterium: methanogen used for sewage treatment
    • Halobacterium: halophile found in the great salt lakes.  Lyses under low salt concentration
  6. Identify medically important bacteria
    • Wolbachia: most common infectious bacterial genus.  Live inside cells of hosts, typically insects, difficult to culture.
    • Burkholderia: able to degrade 100+ sources, can actually grow in disinfectant in hospitals
    • Bordetella: perussis (whooping cough)
    • Neisseria: gonorrhoea
    • Pseudomonas: opportunistic infection, can grow from many C sources (or N, protein, lipid) and with very little
    • Enterics: inhabit the GI tract, fimbrae help adhere to surfaces, sex pili often transmit antibiotic resistance, lyse other bacteria
    • Escherichia: GI tract inhabitant, can be cause ot UTI, diarrhea, foodborne illnes
    • Salmonella: GI tract inhabitant, typhoid fever is most sever illness
    • Shigella: bacillary dysentary, only found in humans
    • Yersinia: cause of the plague, transmitted from rats to humans via flea
    • Campylobacter: leading cause of foodborne intestinal disease
    • Helicobacter: most common cause of peptic ulcers, can cause stomach cancer
    • Staphylococcus: infection of surgical wounds, quick antibiotic resistance development, produces toxins
    • Streptococcus: causes greater variety of diseases than any other group. Beta hemolytic vs. non-beta hemolytic.
    • Enterococcus: leading cause of nosocomial infections
    • Listeria: capable of growth at regigeration temperature
    • Clostridium: due to endospore's resistance
    • Mycobacterium: tuberculosis, lepracy
  7. Indicate which bacteria area: not readily gram stained, intracellular parasites, lack cell walls, acid fast
    • Not readily gram stained: Mycoplasmatales, Mycobacterium, Nocardia,
    • Intracellular parasites: Rickettsia, Brucella, Wolbachia, Coxiella, Chlamydia
    • Lack cell walls: Mycoplasmatales
    • Acid fast: Mycobacterium, Nocardia,