MICROBIOLOGY BLOG FOR STUDENTS (MBLOGSTU): Identification of Gram Negative Bacteria

Gram Negative Bacteria Identifier

Biochemical Test for Identification of Gram Negative Bacteria

Name of Bacteria	Indole	MR	VP	Citrate	Urease	Motility	TSIA	Gas	H₂S
Escherichia coli	+	+	-	-	-	+	Y/Y	+	-
Enterobacter aerogenes	-	-	+	+	-	+	Y/Y	++	-
Enterobacter cloacae	-	+	+	+	+	+	Y/Y	+	-
Salmonella typhimurium	-	+	-	+	-	+	R/Y	+	Strong +
Salmonella Typhi	-	+	-	-	-	+	R/Y	-	Weak +
Salmonella Paratyphi A	-	+	-	-	-	+	R/Y	+	-
Salmonella Paratyphi B	-	+	-	+	-	+	R/Y	+	+
Salmonella Paratyphi C	-	+	-	+	-	+	R/Y	+	+
Klebsiella pneumoniae	-	-	+	+	+	-	Y/Y	++	-
Klebsiella oxytoca	+	-	+	+	+	-	Y/Y	++	-
Shigella dysenteriae	-	+	-	-	-	-	R/Y	-	-
Shigella flexneri	-	+	-	-	-	-	R/Y	-	-
Shigella sonnei	-	+	-	-	-	-	R/Y	-	-
Shigella boydii	-	+	-	-	-	-	R/Y	-	-
Proteus vulgaris	+	+	-	+	+	+	R/Y	+	++
Proteus mirabilis	-	+	+	+	+	+	R/Y	+	++
Vibrio cholerae	+	+	-	d	-	+	Y/Y	-	-
Vibrio parahaemolyticus	d	+	-	d	-	+	R/Y	-	-
Pseudomonas aeruginosa	-	-	-	+	-	+	R/R	-	-
Acinetobacter baumannii	-	-	-	v	v	-	R/R	-	-
Serratia marcescens	-	-	+	+	-	+	R/Y	+/-	-
Edwardsiella tarda	+	+	-	-	-	+	R/Y	+	++
Aeromonas hydrophila	+	+	-	+	-	+	R/Y	+	++
Providencia spp	+	+	+	+	+/-	+	R/Y	-	-
Citrobacter freundii	+	-	+	+	+/-	+	Y/Y or R/Y	+	+/-
Citrobacter diversus	+	-	+	+	+/-	+	Y/Y or R/Y	+	-
Morganella morganii	+	+	-	-	+	+	R/Y	+	-
Yersinia enterocolitica	d	-	-	-	slow +	+	R/Y	-	-