All enterobacteriaceae are facultative aerobe, non-spore-forming Glucose fermenters .

All enteric bacteria are catalase positive except for one group of Salmonella species and Xenoharbus.

Salmonella/Escherichia/Shigella species  cannot be separated into different serotypes because they have the same antigens found on their surface.

Serotyping is determined by the agglutination of bacteria with specific antisera to identify variants of O and H antigens.

K antigen is the Capsular antigen

Adenylate cyclase enzyme catalyzes the transformation of ATP to cyclic adenosine monophosphate (cAMP), leading to a decrease in cyclic adenosine monophosphate (cAMP) level.

The decreased levels of cAMP stimulate the intestinal cells to hyper secret fluids and electrolytes into the lumen of the intestine resulting in watery diarrhea .

Enteroinvasive E.coli has a higher infective dose than Shigella .

The 3 symptoms of HUS include thrombocytopenia, microangiopathic hemolytic anemia, and kidney failure.

K. pneumoniae has a polysaccharide capsule which is responsible for the mucoidal colonies.

 Salmonella, Shigella, Escherichia can tolerate KCN.

Enterobacter is inhibited by KCN.

Fish eye colonies are produced by Enterobacter spp on EMB.

Hafnia is differentiated from Serratia because it is DNAse and Lipase positive.