Coagulase test differentiate Staphylococcus aureus from other Staphylococcus sp

Indole positive bacteria : E. coli, Vibrio cholera
Indole negative bacteria : Klebsiella, Salmonella, Shigella spp.

Citrate positive bacteria: Klebsiella spp.
Citrate negative bacteria: E. coli.

LF = Lactose Fermenter
NLF = Non Lactose Fermenter

Klebsiella Lactose Fermenting

Klebsiella, E coli, Enterobactor, Citrobactor, Serratia, Salmonella, Pseudomonas, Shigella, Proteus all are gram negative bacteria.



Klebsiella, E Coli and Enterobactor are Lactose fermenter (LF)

Citrobactor and Serratia are Late Lactose Fermenter (LLF)


E coli indole positive
Enterobactor indole negative


E coli citrate negative
Klebsiella citrate positive

Klebsiella, E coli, Enterobactor, Citrobactor, Serratia, Salmonella, Pseudomonas, Shigella, Proteus all are gram negative bacteria.



Klebsiella, E Coli and Enterobactor are Lactose fermenter (LF)

Citrobactor and Serratia are Late Lactose Fermenter (LLF)


E coli indole positive
Enterobactor indole negative


E coli citrate negative
Klebsiella citrate positive


PPA test (phenylalanine deaminase or phenylpyruvic acid test) gives positive (greenish colour) for Proteus.


Pseudomonas are Oxidase positive. (Neisseria is also oxidase positive)


Salmonella is a gram negative motile bacteria recognised by motility testing.

1.Among these which is the gram negative cocci ?

A. Streptococcus
B. Neisseria
C. Staphylococcus
D. Escherichia

2. Following these which is not responsible for causing Urinary tract infection ?

A. Escherichia
B. Proteus
C. Enterobactor
D. Shigella

3. Following these which is not a motile bacteria?

A. Escherichia
B. Salmonella
C. Mycobacterium
D. Vibrio


4. Bacteria responsible for plague

A. Yersinia
B. Helicobacter
C. Campylobacter
D. Psedomonas


5. Which is not a gram negative bacteria ?

A. Haemophilus
B. Bordetella
C. Actinomyces
D. Klebsiella

Gram positive and Negative Bacteria and their representative diseases

Urease positive vs negative


Positive - Proteus, Cryptococcus, Corynebacterium, Yersinia, Helicobacter, Brucella


Negative - E coli, Shigella, Salmonella

Textbook Of Medical BioChemistry-8th Edition.pdf

Viva in Biochemistry.pdf

https://microbenotes.com/esbach-test/

Esbach's Test for estimation of Urine Albumin

https://microbiologynote.com/rotheras-test/

Rother's Test for Ketone Body Identification