Whole genome sequences of three Clade 3 Clostridium difficile strains carrying binary toxin genes in China.
Sci Rep
; 7: 43555, 2017 03 06.
Article
em En
| MEDLINE
| ID: mdl-28262711
ABSTRACT
Clostridium difficile consists of six clades but studies on Clade 3 are limited. Here, we report genome sequences of three Clade 3 C. difficile strains carrying genes encoding toxin A and B and the binary toxin. Isolates 103 and 133 (both of ST5) and isolate 106 (ST285) were recovered from three ICU patients. Whole genome sequencing using HiSeq 2500 revealed 4.1-Mb genomes with 28-29% GC content. There were ≥1,104 SNP between the isolates, suggesting they were not of a single clone. The toxin A and B gene-carrying pathogenicity locus (PaLoc) of the three isolates were identical and had the insertion of the transposon Tn6218. The genetic components of PaLoc among Clade 3 strains were the same with only a few nucleotide mutations and deletions/insertions, suggesting that the Tn6218 insertion might have occurred before the divergence within Clade 3. The binary toxin-genes carrying CDT locus (CdtLoc) of the three isolates were identical and were highly similar to those of other Clade 3 strains, but were more divergent from those of other clades. In conclusion, Clade 3 has an unusual clade-specific PaLoc characteristic of a Tn6218 insertion which appears to be the main feature to distinguish Clade 3 from other C. difficile.
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Base de dados:
MEDLINE
Assunto principal:
Toxinas Bacterianas
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Clostridioides difficile
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Genoma Bacteriano
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Infecções por Clostridium
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article