Lecture 1

• How to name a bacteria?


  use genus and species names. Genus is capitalized and species not.
• Bacteria

  a single celled organism, reproduces independently meaning it has ribosomes, contains DNA AND RNA, contains cytoplasm but no nucleus, is found everywhere (normal flora too,) and it does not always need to be "caught" to cause infection/disease, colonizes on skin
• Describe bacteria?

  cocci: round circles in chains or clusters

  Bacilli: long rod like structures either singular or in long chains (rare)

  Gram positive: has this peptidoglycan layer and cell membrane

  Gram negative: has outer membrane, THIN peptidoglycan layer and cell membrane
• What is gram positive?

  stains purple/blue, found above the gut/belt line, does not often lead to serious infection, found in clusters or chains, has thick peptidoglycan layer and cell membrane
• Gram negative?

  stains pink, found below the gut/belt line, causes BAD diseases (infections), has an OUTER MEMBRANE, thin peptidoglycan layer and a cell membrane
• Myobacterium spp.?

  is an exception to gram stain, not positive or negative since it contains a thick membrane capsule that makes a myocolic cell wall. Is called acid fast bacteria instead of positive or negative
• Myoplasma spp?


  is an exception to gram stain. Is not positive or negative since the test is impossible to perform on it. Has no cell wall, peptidoglycan layer so there is nothing to target
• gram positive staphylococcus?

  found above the gut, around nose, colonizes (part of normal flora). Has two categories: Coagulase positive and coagulase negative
• What is coagulase positive?

  staphylococcus aureus, causes MANY infections, is part of our natural skin flora. If found in sterile sites it is important. MRSA is a super bug (resistant to many antibiotics)
• What is coagulas negative?

  anything but staphylococcus aureus, not as important either. is part of the skin flora and not as aggressive, rarely causes primary infections

  ex. S. epidermidis, S. Heminus, S. Waneri, S. Hemolyticus, S. capitis
• Gram positive streptococcus?

  not as aggressive (lower virulence), in mouth or orthopharynx)
• Different categories of gram positive streptococcus?

  Alpha-hemolytic streptococcus, beta-hemolytic streptococcus, and gamma-hemolytic streptococcus.
• Alpha-hymolytic?


  A type of hemolysis where red blood cells are fully lysed, destryoed. Viridans streptococci, not very pathoginic and part of normal flora.

  Streptococci pneumoniae, part of normal oral flora, associated with community acquired pneumonia, bactermia, meningitis, otitis media
• Beta-hymolytic?


  where bloodcells are partially destroyed. Streptococcus pyogenes (group A), streptococcus agalactaea (group B)
• Gamma-hymolytic?


  where no bloodcells are destroyed. Enterococci spp (group D)
• Gram negative cocci?

  found in the oral flora and mucosal surfaces.

  neisseria gonorrhea, neisseria meningitis, neisseria spp. STIs

  Has three levels, primary, sedondary, tertiary

  can colonize oral flora
• Gram positive bacilli?

  common environmental bacteria and skin

  • bacillus anthracis, bacillus cereus, listeria monocytogenes, clostridum difficile, propionibacterium acnes
• Listeria monocytogenes?

  carries food borne outbreaks

  soft cheese and deli meats

  bad for pregnant women

  • placentitis, ammionitis, pre-term labour (known to travel through placenta and infect baby)
• Clostridium spp.?

  all anarobes (oxygen free envirionment)

  made from spores

  infections like tentanus, botulism, anthrax

  makes toxins
• Gram negative bacilli?

  organisms found in fresh water, GI tract

  • can lead to serious infection
  • extremely resistant to treatment (antibiotics)

  escherichia coli, pseudomonas aeruginosa, Klebsiella pneumoniae