ABSTRACT
Analysis of 1,180 diarrheal stool samples in Zanzibar detected 247 Vibrio cholerae O1, Ogawa strains in 2009. Phenotypic traits and PCR-based detection of rstR, rtxC, and tcpA alleles showed that they belonged to the El Tor biotype. Genetic analysis of ctxB of these strains revealed that they were classical type, and production of classical cholera toxin B (CTB) was confirmed by Western blotting. These strains produced more CT than the prototype El Tor and formed a separate cluster by pulsed-field gel electrophoresis (PFGE) analysis.
Subject(s)
Cholera Toxin/metabolism , Cholera/epidemiology , Cholera/microbiology , Vibrio cholerae O1/isolation & purification , Blotting, Western , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Feces/microbiology , Genotype , Humans , Molecular Sequence Data , Molecular Typing , Sequence Analysis, DNA , Tanzania/epidemiology , Vibrio cholerae O1/pathogenicityABSTRACT
Vibrio cholerae O1 El Tor variant strains produced much more cholera toxin than did prototype El Tor strains. The amount of cholera toxin produced by El Tor variant strains both in vitro and in vivo was more or less equivalent to that produced by classical strains.