DETECTION OF PROVISIONAL SEROVARS OF SHIGELLA-DYSENTERIAE AND DESIGNATION AS S-DYSENTERIAE SEROTYPE-14 AND SEROTYPE-15

In initial studies of slide and tube agglutination tests of shigella-l ike isolates from diarrheal stools from Bangladesh, 10 and 8 strains o f Shigella dysenteriae were identified as provisional serovars (serova rs that have been defined but not given a number in the antigenic sche ma) E22383 and E23507, respectively. Further screening of diarrheal st ool isolates in a slide agglutination test with antisera (made with th e international reference strains) to the two provisional serovars of S. dysenteriae identified an additional 36 isolates as belonging to E2 2383 and 8 isolates as belonging to E23507. All strains had properties typical of invasive Shigella strains in that they were positive in th e Sereny test and had the 120- to 140-MDa plasmid associated with inva siveness. On the basis of these markers of pathogenicity and isolation from various geographical locations, now we recommend that provisiona l serovars E22383 and E23507 be designated S. dysenteriae serotypes 14 and 15, respectively.