Morphology & Culture Characteristics of Proteus Vulgaris

MORPHOLOGY AND CULTURE CHARACTERISTICS OF PROTEUS VULGARIS (PR. VULGARIS)

MORPHOLOGY OF PROTEUS VULGARIS (PR. VULGARIS)

ShapeProteus Vulgaris is a short, straight rod shape (bacillus) bacterium.

Size – The size of Proteus Vulgaris is about 1–3 µm × 0.5 µm (micrometer).

Arrangement Of CellsPr. vulgaris is arranged singly, in pairs, or in short chains and sometimes in clusters.

Morphology of Proteus vulgaris - mcroscopic view of Proteus vulgaris
MORPHOLOGY OF PROTEUS VULGARIS (MICROSCOPIC VIEW)

MotilityProteus Vulgaris is an actively motile bacterium and well known for the swarming growth on an ordinary medium like NAM.

FlagellaPr. Vulgaris is a flagellated bacterium with a Peritrichous flagella arrangement i.e. flagella are present all over the surface of the bacterium.

Spores – The Proteus Vulgaris is a non–sporing bacterium.

Capsule – Capsules are not present in Proteus Vulgaris.

Gram Staining Reaction – Proteus Vulgaris is a Gram -ve (Negative) bacterium.



CULTURE REQUIREMENTS OF PROTEUS VULGARIS (PR. VULGARIS)

Special requirementsProteus Vulgaris have no complex nutritional requirements and readily grow in an ordinary media like Nutrient Agar medium (NAM). Commonly the NAM & MacConkey Agar medium is used for the cultivation of Proteus Vulgaris in Laboratory.

 Optimum temperatureProteus Vulgaris ranges from 10–43°C but the optimum temperature for most of the strains is 37°C and usually cultivated at this temperature in laboratories.

⇒ Optimum pHPr. vulgaris can survive alkaline pH as well as acidic pH ranging from 4.0 – 11.0 and the maximum growth of the organism is observed at 6.0 i.e. neutral pH. Also, the pH requirement varies as per the strain of Proteus vulgaris.

Check out the Morphology & Culture Characteristics of Shigella dysenteriae

MORPHOLOGY AND CULTURE CHARACTERISTICS OF SHIGELLA DYSENTERIAE (SH. DYSENTERIAE)

⇒ Oxygen requirementsProteus Vulgaris (Pr. vulgaris) is an aerobic bacterium i.e. grow best in the presence of oxygen and it is also a Facultative anaerobic organism i.e. can grow in the low oxygen environment.

⇒ There are various culture media used for the cultivation of Proteus Vulgaris in the laboratory and most commonly the Nutrient Agar medium and MacConkey Agar medium is used, the other media are as follows –

  • Columbia Horse Blood Agar medium
  • Sheep Blood Agar medium
  • Xylose Lysine Dextrose (XLD) Agar medium
  • Eosin Methylene Blue Agar (EMB Agar) Medium.
  • The liquid medium (Nutrient Broth medium, TSB medium, etc.).

 The Eosin Methylene Blue Agar (EMB Agar) medium can also be used for the cultivation of Proteus Vulgaris in laboratory contains Eosin dye and Methylene Blue dye which inhibits the growth of many gram-positive bacteria, inhibits the growth of Shigella and Salmonella species and supports the growth of Proteus Vulgaris.

CULTURE CHARACTERISTICS OF PROTEUS VULGARIS (PR. VULGARIS)

Cultural CharacteristicsNutrient Agar Medium (NAM)MacConkey Agar mediumBlood Agar MediumEMB Agar medium
ShapeIrregular (due to swarming)CircularIrregular (due to swarming)Circular
Size1-2 mm2-3 mm1-2 mm2-3 mm
ElevationEffuseLow ConvexEffuseEffuse
SurfaceGlisteningSmoothGlisteningGlistening
ColorGreyish whiteColorless or Pale coloredGreyish whiteColorless
StructureTranslucentTransparentTranslucent –OpaqueTransparent
Hemolysis----------γ-Hemolysis (Non-hemolytic)-----

Check out the Morphology & Culture Characteristics of Klebsiella pneumoniae

MORPHOLOGY AND CULTURE CHARACTERISTICS OF KLEBSIELLA PNEUMONIAE (K. PNEUMONIAE)

In Liquid culture media like Trypticase soy broth or Nutrient broth & Peptone Water, the growth of the bacterium occurs as a uniform turbidity in the broth medium with a powdery deposit and Ammoniacal smell which is further analyzed for the morphology (under the microscope), gram reaction, biochemical tests, and Proteus Vulgaris specific tests.

In Blood Agar medium, the Proteus Vulgaris exhibits the swarming and the growth occurs in the whole media plate. Usually, it produces non-hemolytic growth on Blood agar plate but some of the strains are β-Hemolytic.

Proteus Vulgaris on Blood agar medium - Proteus vulgaris on Blood agar plate
PROTEUS VULGARIS CULTURE ON BLOOD AGAR MEDIUM

In MacConkey Agar medium, the colonies of Proteus Vulgaris are pale or colorless due to lack of lactose fermentation which is of great importance in differentiating Pr. vulgaris from other Bacteria present in the specimen, especially from Gram-positive bacteria (S. aureus), E.coli & Klebsiella species which are lactose fermentors and gives Pink colored colonies on MacConkey agar medium. Moreover, the swarming is inhibited in the MacConkey Agar medium due to the presence of Bile Salts.

Proteus vulgaris on macconkey agar medium - colonies of proteus vulgaris on macconkey agar
PROTEUS VULGARIS CULTURE ON MACCONKEY AGAR MEDIUM

The Swarming of Proteus vulgaris is best observed in Nutrient Agar medium, covering the whole plate. The colonies are small, glistening and usually, the growth is irregular due to swarming.

proteus vulgaris on nutrient agar medium - growth of proteus vulgaris on nutrient agar
CULTURE OF PROTEUS VULGARIS ON NUTRIENT AGAR MEDIUM

The swarming of Proteus can be inhibited by

  • Increasing the concentration of agar from 1-2% to 6%.
  • Incorporation of sodium azide, boric acid, or chloral hydrate in the medium.
  • The addition of growth inhibitors like sulphonamides to the medium.
  • Addition of Teepol (a surface active agent) which is present in Teepol Lactose agar medium.
  • The presence of Bile salts in the medium, present in MacConkey agar or DCA medium.

That’s all about the Morphology & Culture Characteristics of Proteus vulgaris



Further Reading:

Culture characteristics of Proteus on XLD Agar medium – Dalynn
Proteus vulgaris – Wikipedia & Wikimedia commons
Proteus on NAM – Sciencebuddies
Proteus on Blood Agar – Medical-Labs

Proteus vulgaris microscopic view – Flickr

Proteus – Nios

Leave a Reply

Your email address will not be published. Required fields are marked *