%0 Journal Article %A ROWE, B. %A GROSS, R. J. %A WOODROOF, D. P. %T Proposal to Recognise Seroovar 145/46 (Synonyms: 147, Shigella 13, Shigella sofia, and Shigella manolovii) as a New Escherichia coli O Group, O164 %D 1977 %J International Journal of Systematic and Evolutionary Microbiology, %V 27 %N 1 %P 15-18 %@ 1466-5034 %R https://doi.org/10.1099/00207713-27-1-15 %I Microbiology Society, %X A biochemically and serologically homogeneous group of bacterial strains is described. The strains were selected because of their biochemical and serological similarity to strain number 145/46, which was isolated from a patient with the symptoms of clinical dysentery in the British Isles in 1946. Similar strains, sometimes called “serotype 147,” have been described as biochemically atypical members of Escherichia coli O group 25. Other studies have suggested, on the basis of biochemical tests and pathogenicity tests, that such strains should be classified as Shigella and the names Shigella 13, S. sofia, S. manolovii, and S. metadysenteriae have been proposed for them. Some workers have proposed that these strains should be regarded as intermediate between Shigella and E. coli. There is little doubt that these organisms have caused outbreaks of bloody diarrhoea resembling bacillary dysentery, but pathogenicity cannot be considered as a criterion for inclusion in the genus Shigella. The present study shows that the organisms can be classified biochemically as E. coli but they are atypical in being nonmotile, anaerogenic, and non-lactose-fermenting; serological studies show that these organisms can easily be distinguished from all currently recognised E. coli O groups (O1 to O163). It is proposed that these strains should be regarded as members of a new E. coli O group, O164. %U https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-27-1-15