This is a correction of an earlier published article.
After the publication of this work, we became aware that the our description of the methods used to identify Shigella spp. did not describe the identification of a subset of Shigella spp. which were untypeable with commercial sera. Additional typing was conducted by Dr. Kaisar A. Talukder and coworkers (Laboratory Sciences Division, ICDDR, B: Centre for Health and Population Research, GPO Box-128, Dhaka-1000, Bangladesh. Email:firstname.lastname@example.org.)
Brief description of the methods used for serotyping the untypeable S. flexneri strains using MASF
All Shigella strains which agglutinated with commercial polyvalent anti-S. flexneri serum (Denka Seiken, Tokyo, Japan) but were untypeable using commercial serotype specific antisera were examined using a panel of monoclonal antibodies against S. flexneri (MASF B) according to the typing scheme shown in Table 1 using monoclonal antibodies from one supplier (Reagensia AB, Stockholm, Sweden) with the exception of MASF 1c which was provided by Dr. N. I. A. Carlin (SBL, Sweden) [2-5]. Untypeable S. flexneri strains which agglutinated strongly with polyclonal MASF B and type antigen factor IV-2 but not with group factor Y-5 or 6 thereby excluding their characterization into serotype 4a or 4b were designated as serotype 4 if they agglutinated with a new antigenic determinant E1037 (IV-1). Untypeable strains which agglutinated with antibodies against the provisional antigen, MASF IV-1 specific for the new antigenic determinant E1037, were designated as 4X. Untypeable strains which agglutinated only with MASF Ic were designated as 1c.
Table 1. S. flexneri serotyping criteria using MASF antibodies
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Talukder KA, Dutta DK, Safa A, Ansaruzzaman M, Hassan F, Alam K, Islam KM, Carlin NI, Nair GB, Sack DA: Altering trends in the dominance of Shigella flexneri serotypes and emergence of serologically atypical S. flexneri strains in Dhaka, Bangladesh.
Talukder KA, Islam MA, Dutta DK, Hassan F, Safa A, Nair GB, Sack DA: Phenotypic and genotypic characterization of serologically atypical strains of Shigella flexneri type 4 isolated in Dhaka, Bangladesh.
Talukder KA, Islam Z, Islam MA, Dutta DK, Safa A, Ansaruzzaman M, Faruque AS, Shahed SN, Nair GB, Sack DA: Phenotypic and genotypic characterization of provisional serotype Shigella flexneri 1c and clonal relationships with 1a and 1b strains isolated in Bangladesh.
The pre-publication history for this paper can be accessed here: