We appreciate and thank Marin & Vicente for a quick analysis of ctxB sequences that we deposited in GenBank under the accession numbers EU932878-EU932884 [Reference Bhuiyan1].
In fact the sequences of the ctxB gene of Zambian strains were deposited as additional information to confirm the result of MAMA-PCR as well as to type the strains following Olsvik et al. overlooking the actual result of the genotype [Reference Olsvik2]. After the report by Safa and co-workers [Reference Safa, Nair and Kong3] we are now sequencing a large number of variant strains of V. cholerae O1 for the ctxB gene that were isolated from cholera-endemic areas globally in order to understand the actual number and location of new genotypes of ctxB. In our published paper, we concentrated our analysis on targeting the pattern of nine virulence regions of V. cholerae O1 especially the regions for VSP-I and VSP-II [Reference Bhuiyan1]. However, Marin & Vicente, in their letter, have clearly identified the new genotypes 10 and 11 in Zambian strains. They have correctly identified three distinct ctxB alleles among Zambian strains, not the two types that we stated in our published paper [Reference Bhuiyan1]. We did not analyse the clonal lineages in terms of genotype of the strain. However, as new genotype 10 (EU932878) belongs to cluster A, genotype 11 belongs to cluster B as the other strain 224/12 (EU932882) isolated in 2004 was included for pulsed-field gel electrophoresis in this study from Zambia [Reference Bhuiyan1].
