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Identification of novel Clostridium perfringens type E strains that carry an iota toxin plasmid with a functional enterotoxin gene.

Miyamoto K, Yumine N, Mimura K, Nagahama M, Li J, McClane BA, Akimoto S - PLoS ONE (2011)

Bottom Line: The ∼65 kb plasmid is closely related to the pCPF4969 cpe plasmid of type A isolates.MLST analyses indicated these isolates belong to a unique cluster of C. perfringens.Overall, these isolates carrying a variant functional cpe gene and iota toxin genes represent unique type E strains.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Wakayama Medical University School of Medicine, Wakayama, Japan. kazuaki@wakayama-med.ac.jp

ABSTRACT
Clostridium perfringens enterotoxin (CPE) is a major virulence factor for human gastrointestinal diseases, such as food poisoning and antibiotic associated diarrhea. The CPE-encoding gene (cpe) can be chromosomal or plasmid-borne. Recent development of conventional PCR cpe-genotyping assays makes it possible to identify cpe location (chromosomal or plasmid) in type A isolates. Initial studies for developing cpe genotyping assays indicated that all cpe-positive strains isolated from sickened patients were typable by cpe-genotypes, but surveys of C. perfringens environmental strains or strains from feces of healthy people suggested that this assay might not be useful for some cpe-carrying type A isolates. In the current study, a pulsed-field gel electrophoresis Southern blot assay showed that four cpe-genotype untypable isolates carried their cpe gene on a plasmid of ∼65 kb. Complete sequence analysis of the ∼65 kb variant cpe-carrying plasmid revealed no intact IS elements and a disrupted cytosine methyltransferase (dcm) gene. More importantly, this plasmid contains a conjugative transfer region, a variant cpe gene and variant iota toxin genes. The toxin genes encoded by this plasmid are expressed based upon the results of RT-PCR assays. The ∼65 kb plasmid is closely related to the pCPF4969 cpe plasmid of type A isolates. MLST analyses indicated these isolates belong to a unique cluster of C. perfringens. Overall, these isolates carrying a variant functional cpe gene and iota toxin genes represent unique type E strains.

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Related in: MedlinePlus

Comparative alignment of pCPPB-1 variant cpe plasmid versus pCPF4969 classical cpe-plasmid.Map displays ORFs identified by ORF Finder using the obtained the variant cpe-encoding plasmid (pCPPB-1) sequence. A blue line marks the putative plasmid transfer region, an orange line delineates toxin, and a pink line indicated the region homologous with a part of pCPF4969 variable region. Potential roles of each ORF are indicated by the key in the lower right-hand corner of the figure.
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pone-0020376-g002: Comparative alignment of pCPPB-1 variant cpe plasmid versus pCPF4969 classical cpe-plasmid.Map displays ORFs identified by ORF Finder using the obtained the variant cpe-encoding plasmid (pCPPB-1) sequence. A blue line marks the putative plasmid transfer region, an orange line delineates toxin, and a pink line indicated the region homologous with a part of pCPF4969 variable region. Potential roles of each ORF are indicated by the key in the lower right-hand corner of the figure.

Mentions: Complete sequencing of the cpe plasmid (named pCPPB-1) in PB-1 revealed a size of 67,479 bp, encoding 72 putative ORFs (Figure 2). Analysis of pCPPB-1 revealed that this plasmid consists of three regions: a putative plasmid replication and transfer region, a toxin region, and a variable region.


Identification of novel Clostridium perfringens type E strains that carry an iota toxin plasmid with a functional enterotoxin gene.

Miyamoto K, Yumine N, Mimura K, Nagahama M, Li J, McClane BA, Akimoto S - PLoS ONE (2011)

Comparative alignment of pCPPB-1 variant cpe plasmid versus pCPF4969 classical cpe-plasmid.Map displays ORFs identified by ORF Finder using the obtained the variant cpe-encoding plasmid (pCPPB-1) sequence. A blue line marks the putative plasmid transfer region, an orange line delineates toxin, and a pink line indicated the region homologous with a part of pCPF4969 variable region. Potential roles of each ORF are indicated by the key in the lower right-hand corner of the figure.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105049&req=5

pone-0020376-g002: Comparative alignment of pCPPB-1 variant cpe plasmid versus pCPF4969 classical cpe-plasmid.Map displays ORFs identified by ORF Finder using the obtained the variant cpe-encoding plasmid (pCPPB-1) sequence. A blue line marks the putative plasmid transfer region, an orange line delineates toxin, and a pink line indicated the region homologous with a part of pCPF4969 variable region. Potential roles of each ORF are indicated by the key in the lower right-hand corner of the figure.
Mentions: Complete sequencing of the cpe plasmid (named pCPPB-1) in PB-1 revealed a size of 67,479 bp, encoding 72 putative ORFs (Figure 2). Analysis of pCPPB-1 revealed that this plasmid consists of three regions: a putative plasmid replication and transfer region, a toxin region, and a variable region.

Bottom Line: The ∼65 kb plasmid is closely related to the pCPF4969 cpe plasmid of type A isolates.MLST analyses indicated these isolates belong to a unique cluster of C. perfringens.Overall, these isolates carrying a variant functional cpe gene and iota toxin genes represent unique type E strains.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Wakayama Medical University School of Medicine, Wakayama, Japan. kazuaki@wakayama-med.ac.jp

ABSTRACT
Clostridium perfringens enterotoxin (CPE) is a major virulence factor for human gastrointestinal diseases, such as food poisoning and antibiotic associated diarrhea. The CPE-encoding gene (cpe) can be chromosomal or plasmid-borne. Recent development of conventional PCR cpe-genotyping assays makes it possible to identify cpe location (chromosomal or plasmid) in type A isolates. Initial studies for developing cpe genotyping assays indicated that all cpe-positive strains isolated from sickened patients were typable by cpe-genotypes, but surveys of C. perfringens environmental strains or strains from feces of healthy people suggested that this assay might not be useful for some cpe-carrying type A isolates. In the current study, a pulsed-field gel electrophoresis Southern blot assay showed that four cpe-genotype untypable isolates carried their cpe gene on a plasmid of ∼65 kb. Complete sequence analysis of the ∼65 kb variant cpe-carrying plasmid revealed no intact IS elements and a disrupted cytosine methyltransferase (dcm) gene. More importantly, this plasmid contains a conjugative transfer region, a variant cpe gene and variant iota toxin genes. The toxin genes encoded by this plasmid are expressed based upon the results of RT-PCR assays. The ∼65 kb plasmid is closely related to the pCPF4969 cpe plasmid of type A isolates. MLST analyses indicated these isolates belong to a unique cluster of C. perfringens. Overall, these isolates carrying a variant functional cpe gene and iota toxin genes represent unique type E strains.

Show MeSH
Related in: MedlinePlus