Bacterial pathogens of GIT - Gram-negative bacilli

Gram neg bacilli

Facultative Anaerobe

Microaerophile

Aeromonas spp.

Enterobacteriaceae spp.

Vibrio spp.

Campylobacter spp.

Curved

Facultative Anaerobe

Oxidase +ve

Catalase +ve

Urease -ve

Hippurate hydrolysis

C. coli

C. jejuni only

C. jejuni on Skirrow

C. coli on Skirrow

C. coli on CCDA

Oxidase +ve

Catalase +ve

Urease +ve

Sucrose fermenting

V. cholera

V. parahaemolyticus

Would be yellow on TCBS

No

Yes

V. parahaemolyticus on TCBS

V. parahaemolyticus on CHOC

V. parahaemolyticus on MH

Hippurate Hydrolysis test.

Purple = +ve

Salmonella spp

Yersinia spp.

Salmonella typhimurium on MH

Salmonella typhimurium on XLD

Yersinnia enterocolitica on MH

Yersinia enterocolitica on CIN

Aeromonas hydrophila on MAC3

Aeromonas hydrophila on CIN

ANTIGEN DETECTION

Urease +ve

Urease +ve

Oxidase

Positive

Negative