additional notes of sir Caligtan

• Yersinia pestis


  • Circular, Low Convex, Smooth; mucoid (capsulated), Greyish white, Translucent–Opaque, γ-Hemolysis (Non-Hemolytic) in blood agar
  • Circular, Low Convex, Smooth; mucoid (capsulated), colorless, Transparent in MacConkey agar
  • Circular, Low Convex, Smooth; mucoid (capsulated), Greyish white, Transparent–Opaque in Nutrient Agar Medium
• Salmonella typhi


  • Circular, Low Convex, Smooth, Greyish white, Translucent, γ-Hemolysis (Non-Hemolytic) in blood agar
  • Circular, Low Convex, Smooth, colorless, Transparent in MacConkey agar
  • Circular, Low Convex, Smooth, red with black center, Translucent–Opaque in Xylose Lysine Deoxycholate Agar (XLD) Medium
  • Circular, Convex, Smooth, Glistening, Jet Black with metallic sheen, Opaque in Wilson & Blair bismuth sulfite Medium
  • Circular, Low Convex, Smooth, Greyish white, Translucent in the Wilson & Blair bismuth sulfite medium
• Pseudomonas aeruginosa


  • Irregularly edged circular, Flat, smooth (fresh isolation); Mucoid (When slime layer is formed), Greyish white, Translucent–Opaque, β-Hemolysis (in some strains) in a blood agar
  • Circular, Low Convex, Smooth (fresh isolation); Mucoid (When slime layer is formed), Colorless, Transparent in MacConkey agar
  • Circular, Low Convex, Smooth (fresh isolation); Mucoid (When slime layer is formed), Greenish blue (due to pigment production) and opaque in Cetrimide agar medium
  • Irregular, Low Convex, Smooth (fresh isolation); Mucoid (When slime layer is formed), Greenish blue (due to pigment production), Translucent–Opaque in Nutrient Agar Medium
• Escherichia coli


  • Green metallic sheen in Eosin Methylene Blue agar
  • Opaque in a smooth and rough form, a low convex, grayish, white, moist, smooth, large, and circular in the Nutrient Medium Agar
  • Dry pink, flat, pinkish, circular, moist, smooth, and of entire margin colonies in MacConkey Agar (an indication of a rapid lactose fermenters)
  • Pink to red colonies which fluoresces blue under UV light in the Violet Red Bile Agar
  • Smooth (fresh isolation); Rough (repeated subculture); mucoid (capsulated strains), Greyish white, Translucent–Opaque, β-Hemolysis (in some strains) in blood agar
• Staphylococcus aureus


  • Large opaque, round, creamy, white to yellowish colonies displaying beta-hemolysis on blood agar
• Streptococcus pyogenes


  • Small translucent colonies displaying beta-hemolysis on blood agar
• Streptococcus pneumoniae


  • Circular, Glistening or Mucoid (due to Capsule production), Clear, Whitish or Very light Yellow as per the strain, Transparent or Opaque, small colonies with raised edges displaying alpha-hemolysis on blood agar
  • Circular, Dome-Shaped or flattened colonies, Glistening or Mucoid (due to Capsule production), Clear, Whitish or Very light Yellow as per the strain, Transparent or Opaque in Nutrient Agar Medium
  • Circular, Glistening or Mucoid (due to Capsule production), Clear, Whitish or Very light Yellow as per the strain, Transparent or Opaque in Crystal Violet-Nalidixic acid–Gentamycin (CVNG) Agar medium
• Klebsiella


  • Pink pinpoint colony in Violet Red bile agar
• Serratia marcescens


  • Brick-red pigment that is evident on MacConkey agar (slightly visible on chocolate agar plate, incubation at room temperature enhances the brick-red pigmentation)
• Bacillus cereus


  • Large, rough, hemolytic on sheep blood agar plate

  
• The importance of the ability to recognize and describe the colony morphology (colony characteristics) of isolates recovered on culture media and interpretation of Gram stained smears from clinical specimens cannot be overemphasized
• Although Gram-stained smears provide initial identification of microorganisms by microscopic characterization, description of the physical growth characteristics of microorganisms on laboratory media facilitates the initial identification processes

  
• Presumptive identification by colony morphology

  Extends the usefulness of colony characterization beyond a pathway to organism identification, may include providing a presumptive identification to the physician, enhancing the quality of patient care through rapid reporting of results and by increasing the cost-effectiveness of laboratory testing
• Microbiologists must be able to differentiate potential pathogens from the "usual" inhabitants (microbiota) of the upper respiratory tract and direct the diagnostic workup toward only potential pathogens
• Potential pathogens are presumptively identified by colony characteristics, and pre-identification procedures are performed only on those isolates