|Pathological and microbiological findings from five affected calves|
|Calf no.||Pathological changesa||E. coli serotypeb||Positive samples||MLD50for E. coli (CFU)c|
|1||severe||O8||intestine, rectal swabs||5.45 × 109|
|3||severe||O8||intestine, rectal swabs||ND|
|4||severe||O8||intestine, rectal swabs||ND|
a The pathological changes of intestines from affected calves were estimated by visual examination.
b The serotypes of each strains were determined by agglutination test with 25 prevalent antiserums of pathogenic E. coli.
c MLD50 were determined by intraperitoneally inoculating six mice in each group with 50 μl of serial 10-fold dilutions E. coli and calculated by the method of Hamilton et al. .
d ND indicates that the LD50 of these strains was not determined.
He et al.
He et al. BMC Veterinary Research 2012 8:222 doi:10.1186/1746-6148-8-222