Additionally, three particular mutations at positions 137, 472 and 487 were found to cause non-synonymous mutations. The substitutions of G137T and C487A in all 14 classical Inaba strains, compared to the rfbT sequence of El Tor Ogawa strain B33, resulted in a replacement of W46L and Q163K, respectively, the same as had been found in the classical Ogawa strains (Additional file 2: Figure S1). The substitution of T472C of rfbT in strains FJ05234, ZJ05023, FJ147, GD05039, HL08091 and CIRS101 resulted in a change of S158P of RfbT, which is the only single mutation found in these strains

and suggests that a Ser residue at this position is critical for the function of the RfbT transferase. Another important site is position 482, for MGCD0103 the resulting Y161 to F substitution determined Inaba phenotype in XJ05021 too. The insertion of C at the position after C-307 occurred in all 14 classical Inaba strains, but caused two different mutations (Table 1, Additional file 2: Figure S1). In strains 16121, 16148, 16510, 16186, 16177, 16159, 16156, and NIH35A3, this insertion caused a frameshift mutation, subsequently formed an internal stop codon after position 348, leading to premature termination of RfbT translation. Whereas in strains 569B, 1119, 16020, 16002, 16505 and 16507, the reading frame was maintained since this insertion was

counteracted by the prior deletion at position 303. The combined effect of the two sites of mutations led to the replacement of T102H in these strains. The Inaba phenotype of theses strains resulted from the truncated RfbT caused this website by an A-494 deletion or G655T substitution (only for 569B) on the posterior sequence. Strains V01, C6706, X190 which were isolated from South America had identical

single nucleotide mutation different from E506 isolated from America. In addition, 48.0% (47/98) of the strains were noted to have short-sequence indels (insertions/deletions) resulting in truncated and prematurely-terminated RfbT proteins. Characteristic mutations of Inaba strains Metalloexopeptidase in the Inaba dominant https://www.selleckchem.com/products/LY2228820.html epidemics in China During the cholera epidemics from 1961 to 2008 in China, Ogawa/Inaba serotype shifts were observed. Three Inaba serotype dominant multiyear epidemics occurred in 1976–1989, 2001–2002 and around 2005. In this study, most (42/45) Inaba strains isolated in 1979–1988 displayed the identical mutation of 11-bp (GCTGAACATCC) deletion (Figure 3). These strains were isolated from 11 different provinces, and were characterized with the marker mutation of rfbT in the epidemics (Table 1). PFGE subtyping on 36 of these 41 strains (Additional file 3: Figure S2) showed that 17 strains possessed the same pattern, while other patterns only displayed 1–3 band differences compared to the predominant pattern, with similarity coefficient values of 93.0%-97.7%, indicating they were closely related in terms of their genetic background.