BACTE WEEKLY

• Staphylococcus aureus


  • Butyrous appearance
  • Medium sized creamy/oily appearance
  • Golden yellow pigment
• Staphylococcus albus


  • White pigment
• Staphylococcus citreus


  • Lemon yellow pigment
• Streptococcus


  • Small pinpoint colonies
• Moraxella catarrhalis


  • "Hockey puck" colonies
  • Intact colonies
• Bacillus anthracis


  • "Beaten egg white consistency"
  • Medusa Head colonies/lion head/ cut glass appearance
• Bacillus anthracis


  1. Inverted fir tree/ inverted pine tree

  2. String of pearls colonies
• Media used


  • Blood Agar Plate (BAP)
  • Mueller Hinton Agar (MHA) with 10u Penicillin
  • BAP with 5u of Penicillin
• Clostridium perfringes


  • Target Hemolysis/ Double zone hemolysis
  • Inner-B; outer-a
• Clostridium botulinum


  • "Mother of Pearl"
  • "gas on water" appearance
• Clostridium botulinum exhibits a (+) Lipase Reaction on Egg yolk Agar
• Clostridium difficile


  • Horse stable/ barnyard odor
  • "CHARTREUSE" fluorescence
• Clostridium difficile exhibits yellow fluorescence on BAP
• Listeria monocytogenes


  • Inverted Christmas tree/ umbrella like appearance
• Listeria monocytogenes


  Sulfide Indole Motility Medium (SIM)
• Erysopelothrix rhusiopathiae


  • Test tube brush/ bottle brush/ Pipe cleaner pattern of growth
• Erysopelothrix rhusiopathiae


  Gelatin Media
• Corynebacterium diptheriae


  • Gray to black colonies
  • Picket fences/Chinese character appearance
  • Black colonies with brown halo
• Media used


  • Cystine Tellurite Blood Agar
  • Cystine Trypticase Agar
  • Tinsdale Medium (with Tellurite)
• Mycobacterium tuberculosis


  • Cauliflower like growth
  • Exhibits "Cording"
  • Luxuriant growth in curved strands
• Mycobacterium bovis


  • Water droplet colonies
• Mycobacterium xenopi


  • Bird's nest colonies
• Escherichia coli


  • Pink colonies with greenish metallic sheen
• Media used


  • Eosin Methylene Blue (EMB)/ Levine medium
• Klebsiella pnuemoniae


  • Mucoid colonies
• Klebsiella pnuemoniae colonies are mucoid due to the presence of a capsule
• Enterobacter


  • Pink-purple with dark center "Fish eye" colonies
• Media used


  • EMB
• Proteus


  • Swarming of colonies- growth outside the streaking pattern
• Media used


  • BAP
• Yersinia pestis


  • Stallactite/ flocculent growth (evenly distributed)
  • Hammered colonies
• Media used


  • BAP
  • MacConkey Agar (MAC)
• Yersinia enterocolitica


  • Bull's eye colonies
• Media used


  • Cefsulodin-Irgasan-Novobiocin (CIN)
• Serratia marcescens


  • Prodigiosin (red pigment)
• Serratia odorifera


  • Rancid potato like odor
• Peptidoglycan consists of alternating sugars (NAM and NAG) crosslinked by short polypeptide chains.
• The cell wall is composed of peptidoglycan, which provides structural support to the bacterial cell.
• Bacteria are prokaryotic cells that lack membrane-bound organelles.
• Some bacteria are classified as anaerobic, meaning they can survive and thrive in environments without oxygen.