Retracted:wbeT sequence typing and IS1004 profiling ofVibrio choleraeisolates

Abstract

Aims: To investigate the molecular basis for serotype variation in Vibrio cholerae O1 and the genetic relatedness amongst different serotypes isolated from 2004 to 2008 in Iran. Methods and Results: Despite the presence of all three serotypes of V. cholerae O1 (Ogawa, Inaba and Hikojima) in Iran in the last decade, the Inaba strains have been the dominated serotype. Sequence analysis of wbeT determined only a single substitution of G for A at position 295 in all Inaba strains resulting in a replacement of serine to proline. No difference was found in the copy numbers and profile of IS1004 between the classical and El Tor V. cholerae O1 strains, supporting the clonality amongst the isolates obtained over 5 years in Iran. In addition, Southern blots of HpaII‐digested chromosomal DNAs of our Ogawa and Inaba isolates showed the presence of an incomplete copy of IS1004 for all isolates. Conclusions: IS1004 profiling can be a reliable method for analysis of clonal dissemination of V. cholerae. The results indicated that specific point mutation at a particular position within the wbeT of V. cholerae O1 strains in Iran may occur which, in turn, may result in serotype switching. Significance and Impact of the Study: Understanding the molecular basis for serotype conversion of V. cholerae and their genetic relatedness could give insights for the incoming cholera epidemic prediction and control.

Sequence polymorphisms of rfbT among the Vibrio cholerae O1 strains in the Ogawa and Inaba serotype shifts

“…T472C was the only nonsynonymous mutation that accounts for a serotype shift in the Inaba strains in 2005, and we experimentally demonstrated the critical role of a serine at this site for the function of RfbT. The same single substitution was also reported in the Inaba strains isolated during different years (2005–2008) in Iran [42] and India [41]. …”

“…Three single nucleotide substitutions and deletion mutations of rfbT have been reported which caused serotype switching due to a frameshift or crucial amino acid residue change in RfbT [22,41,42]. In our study much more mutations are found in the Inaba serotype strains, including single amino acid residue substitutions, frameshifts caused by single nucleotide and short fragment insertions/deletions, and transposition events.…”

Development of Stable Vibrio cholerae O1 Hikojima Type Vaccine Strains Co–Expressing the Inaba and Ogawa Lipopolysaccharide Antigens

“…Accession number JX565662) where the phenotype is reported as Inaba. We have found the same mutation in additional Inaba strains in our strain collection [17] and this specific wbeT mutation has been reported also by other groups as associated with the Inaba serotype [18] , [19] . No other mutations associated with a Hikojima phenotype have been defined.…”

Investigation into immunological responses against a native recombinant CTB whole-cell Vibrio cholerae vaccine in a rabbit model

“…Regional cholera outbreaks from 2005 through 2009 in Iran were due to Inaba strains that have been developed from their prevailing Ogawa (before 2005) by point mutation in O‐antigen‐encoding cluster ( wbe T) (Sharifnia et al . ). Furthermore, sequence analysis revealed the presence of two ctxB genotypes among V. cholerae strains isolated from recent outbreaks (2004–2009) (Aliabad et al .…”