Bacteria features

Organisms which do not gram stain well

  • These Rouges May Microscopically Lack Color.
  • Treponema,Rickettsia,Mycobacteria,Mycoplasma,Legionella pneumophila,Chlamydia.
  • Oh My no cellwall.

Intracellular Organisms

Obligate Intracellular

  • Mycoplasma,Rickettsiae.
  • RiCh organisms stay inside

Facultative Intracellular

Sally Myc and Bruce Neednot Live FreeLY.


Obligate anaerobes

  • ABC are anaerobes.
  • Actinomycetes,Bacteroids,Clostridium.
  • Anaerobes lack Catalase,Superoxide dismutase so susceptible to oxidative damage.
  • Aminoglycosides are ineffective because these antibiotis require O2 to enter into the cell.

Encapsulated bacteria

  • Some Killers Have Pretty Nice Capsules.
  • Streptococcus Pneumoniae
  • Klebsiella penumoniae
  • H.Influenza B
  • Pseudomonas aeroginosa
  • N.Meningitidis
  • Cryptococcus
  • Positive Quellung reaction.

Urease Positive

  1. Ptoteus
  2. Ureaplasma
  3. H.pylori
  4. Klebsiella

Gram positive and Gram negative

All cocci are gram positive except Neisseria

All bacilli are gram negative except DATTA

  1. Diptheria
  2. Actinomycetes
  3. Tetani
  4. Tuberculosis
  5. Anthrax bacillus

Motility of Organisms

  1. Dartling motility/Swarm of Gnats-Cholera
  2. Stately motility-Clostridia
  3. Swarming motility-Proteus
  4. Spinning motility-Fusobacterium gyrans
  5. Tumbling motility-Listeria

Bacterial Growth factors

  1. Salmonella Typhi-Tryptophan
  2. Gonococci-Glutathione
  3. H.influenzae-Factors V and X

Generation time

  1. Coliforms-20 minutes
  2. Tubercle bacilli-14 hours
  3. Lepra bacillus-12 to 13 days.

To remember:Time to cook a cauliflower 20 minutes,for tubercle bacilli it becomes hours as sputum samples are taken hours apart.Leprosy requires constant contact to develop so it becomes several days.

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