Proteus and Providencia Species : Morphology,Diagnosis and Cultural characteristics

Proteus and Providencia Species : Morphology,Diagnosis and Cultural characteristics

The Proteus and Providencia genera belong to the Proteeae of the Enterobacteriaceae family. The members of both these genera are gram negative, motile bacilli, aerobic and facultative anaerobic and can grow in basic media.A characteristic feature that distinguishes tribe Proteeae from other members of Enterobacteriaceae…

Methyl Red Test Principle,Procedure and Result interpretation

Methyl red test MLTGEEKS

MR Test is a quantitative biochemical tests for identification of bacteria by detection of acid production which requires positive organisms to produce strong acid (lactic, formic) from glucose through the mixed acid fermentation pathway.Methyl red is a pH indicator having a range between 6.0(yellow) and…

Phenylalanine Deamination test procedure and result interpretation

Phenylalanine Deamination test MLTGEEKS

The ability of Proteus species to be able to deaminate phenylalanine to phenylpyruvic acid  using the enzyme Phenylalanine ammonia-lyase (pal enzyme) is an important and useful reaction in the differentiation of members of the family of Enterobacteriaceae.This biochemical tests for identification of bacteria  is used…

Nitrate broth and Nitrate Reduction Test Principle and Result interpretation

Nitrate broth and Nitrate Reduction test MLTGEEKS

Nitrate Broth is a growth media used to carryout  the biochemical test ”nitrate reductase test”.The purpose of nitrate reduction test is to detect nitrate reduction by some bacteria. The ability to reduce nitrate by the enzyme Nitrate reductase found in some bacteria is valuable for differentiating…

Kligler Iron Agar principles,composition and slants interpretation

Kligler iron slant MLTGEEKS

Kligler Iron Agar abbreviated KIA is a growth media recommended for the differential identification of gram-negative enteric bacilli from clinical and non clinical samples based on the fermentation  sugars that is dextrose, lactose and the production of Hydrogen sulphide Those bacteria that ferment any of…

ONPG test principles,Composition and Cultural response

ONPG TEST MLTGEEKS

Ortho-nitrophenyl-b-D-galactopyranoside abbreviated ONPG is a microbiological biochemical test used for the rapid detection of  the enzyme b-galactosidase activity in some microorganisms, especially those late lactose fermenters (cryptic lactose fermenters). Lactose fermentation by microorganisms requires a couple of enzymes and one of which is beta-galactosidase ONPG…

Triple Sugar Iron Agar Principles,composition and colony characteristics

triple-sugar-iron-agar-test

Triple Sugar Iron Agar  was originally proposed by Sulkin and Willett and modified by Hajna for the identification of  Enterobacteriaceae.It is selective growth media recommended for identification of gram-negative enteric bacilli on the basis of  sugars such as dextrose, lactose and sucrose fermentation and hydrogen…

Simmons’ citrate agar Principles,composition and colony characteristics

Simmon-citrate-agar-A-Green-No-growth-B-GreenPositive-Growth

Simmons’ citrate agar is differential growth media recommended for  gram-negative bacteria or members Enterobacteriaceae  on the basis of citrate utilization.That is,useful for organisms that uses citrate as a carbon and source of energy. It is also defined as  a selective and differential medium that tests…

Motility Indole Urea Principle, Composition, Preparation and Colony Characteristics

Motility indole urea test MLTGEEKS

Abbreviated (MIU), Motility Indole Urea Medium base is used for the differentiation of Enterobacteriaceae. This medium is based on motility, urease and indole production. This medium contains peptones that provide carbon and nitrogen required for growth of bacteria. Urea provides a source of nitrogen for…