Table 1.

Types of point mutation(s) and respective incidence among the 335 clinical isolates

SacII siteType of mutationAmino acid changeNucleotide changeIncidence (no. [%] of strains)
PositiveWild typeNoneNone243 (72.5)
Silent mutationsAla-67→Ala (silent)GCC→GCT2 (0.6)
Arg-68→Arg (silent)CGT→CGA9 (2.7)
Pro-79→Pro (silent)CCG→CCA6 (1.8)
Arg-91→Arg (silent)CGC→CGT5 (1.5)
Single missense mutations with or without silent mutationAsp-87→AsnGAC→AAC2 (0.6)
Pro-79, Asp-87→Pro (silent), GlyCCG, GAC→CCA, GGC1 (0.3)
Gln-106→LeuCAG→CTG1 (0.3)
Double missense mutationsAla-67, Asp-87→Ser, GlyGCC, GAC→TCC, GGC1 (0.3)
NegativeSilent mutationAla-84→Ala (silent)GCG→GCA0a
Single missense mutations with or without silent mutationThr-83→IleACC→ATC60 (17.9)
Arg-68, Thr-83→Arg (silent), IleCGT, ACC→CGA, ATC2 (0.6)
Thr-83, Arg-91→Ile, Arg (silent)ACC, CGC→ATC, CGT1 (0.3)
Ala-84→ProGCG→CCG1 (0.3)
Ala-84, Asp-87→Ala (silent), TyrGCG, GAC→GCA, TAC0b
Double missense mutationsThr-83, Asp-87→Ile, GlyACC, GAC→ATC, GGC1 (0.3)
Thr-83, Asp-87→Ile, AsnACC, GAC→ATC, AAC0c
Thr-83, Asp-87→Ile, HisACC, GAC→ATC, CAC0c
Total335 (100)
  • a Found in strain P4394 (13).

  • b Found in strain Y4492 (13).

  • c Constructed by site-directed mutagenesis by introduction into plasmid pGL2B5.