Six new E. coli O groups: O165, O166, O167, O168, O169 and O170.

Six Escherichia coli strains are established as antigenic test strains for six new O groups, O165, O166, O167, O168, O169 and O170. They are isolates from diarrhoea but only O167 and O168 are enterotoxigenic (ETEC). The O170, O169 and O166 strains are the earlier provisional O group strains OX1, OX2 and OX8, respectively.