[Antigenic analysis and identification of serotype for an arguable strain of Shigella]

A strain of Shigella, 51331, was isolated abroad in 1935, and stored in The Center for Medical Culture Collection, Beijing. Since the serotype of this strain was arguable in China. It was identified as Sh. flexneri var. X with antigenic analysis. As agglutinin absorption technic was used in preparing diagnostic factor serum, it appears that the culture of strain 51331 could be agglutinated by Shigella antiserum flexner type 3 (Sh. flexneri) made in China and England. The present author suggested that diagnostic serum for type 3 or Sh. flexneri should be checked up with the strain 51331 for type factor specific. Strain 51331 is, therefore, useful for purpose of identification when preparing diagnostic serum for Shigella.