Project description:Clostridium perfringens toxinotype D, toxinotype E, and gastroenteritis-linked BEC/CPILE-positive strains have never been reported in healthy children. We isolated, whole-genome sequenced and bioinformatically characterised three C. perfringens isolates-type D (IQ1), type E (IQ2) and BEC/CPILE-positive (IQ3), recovered from the stools of three healthy two-year-olds, which were further compared to 128 C. perfringens genomes available from NCBI. The analysis uncovered a previously under-described putative toxin gene alv (alveolysin) encoded by isolates IQ2 and IQ3, which appeared to be a clade-specific trait associated with strains from domestic animals. A plasmid analysis indicated that the iota-toxin was encoded on a near-intact previously described plasmid pCPPB-1 in type E strain IQ2. The BEC genes becA and becB were carried on a near-identical pCPOS-1 plasmid previously associated with Japanese gastroenteritis outbreaks. Furthermore, a close phylogenetic relatedness was inferred between the French C. perfringens type E isolates cp515.17 and newly sequenced IQ2, suggesting geographical links. This study describes novel C. perfringens isolates from healthy individuals which encode important toxin genes, indicating the potential spread of these veterinary and clinically important strains and mobile genetic elements, and highlights areas for future research.
Project description:Enterotoxin-producing C. perfringens type A is a common cause of food poisonings. The cpe encoding the enterotoxin can be chromosomal (genotype IS1470) or plasmid-borne (genotypes IS1470-like-cpe or IS1151-cpe). The chromosomal cpe-carrying C. perfringens are a more common cause of food poisonings than plasmid-borne cpe-genotypes. The chromosomal cpe-carrying C. perfringens type A strains are generally more resistant to most food-processing conditions than plasmid-borne cpe-carrying strains. On the other hand, the plasmid-borne cpe-positive genotypes are more commonly found in human feces than chromosomal cpe-positive genotypes, and humans seem to be a reservoir for plasmid-borne cpe-carrying strains. Thus, it is possible that the epidemiology of C. perfringes type A food poisonings caused by plasmid-borne and chromosomal cpe-carrying strains is different. A DNA microarray was designed for analysis of genetic relatedness between the different cpe-positive and cpe-negative genotypes of C. perfringens strains isolated from human, animal, environmental and food samples. The DNA microarray contained two probes for all protein-coding sequences in the three genome-sequenced strains (C. perfringens type A strains 13, ATCC13124, and SM101). The chromosomal and plasmid-borne C. perfringens genotypes were grouped into two distinct clusters, one consisting of the chromosomal cpe-genotypes and the other consisting of plasmid-borne cpe-genotypes. Analysis of the variable gene pool complemented with the growth studies demonstrate different carbohydrate and amine metabolism in the chromosomal and plasmid-borne cpe-carrying strains, suggesting different epidemiology of the cpe-positive C. perfringens strain groups.
Project description:Enterotoxin-producing C. perfringens type A is a common cause of food poisonings. The cpe encoding the enterotoxin can be chromosomal (genotype IS1470) or plasmid-borne (genotypes IS1470-like-cpe or IS1151-cpe). The chromosomal cpe-carrying C. perfringens are a more common cause of food poisonings than plasmid-borne cpe-genotypes. The chromosomal cpe-carrying C. perfringens type A strains are generally more resistant to most food-processing conditions than plasmid-borne cpe-carrying strains. On the other hand, the plasmid-borne cpe-positive genotypes are more commonly found in human feces than chromosomal cpe-positive genotypes, and humans seem to be a reservoir for plasmid-borne cpe-carrying strains. Thus, it is possible that the epidemiology of C. perfringes type A food poisonings caused by plasmid-borne and chromosomal cpe-carrying strains is different. A DNA microarray was designed for analysis of genetic relatedness between the different cpe-positive and cpe-negative genotypes of C. perfringens strains isolated from human, animal, environmental and food samples. The DNA microarray contained two probes for all protein-coding sequences in the three genome-sequenced strains (C. perfringens type A strains 13, ATCC13124, and SM101). The chromosomal and plasmid-borne C. perfringens genotypes were grouped into two distinct clusters, one consisting of the chromosomal cpe-genotypes and the other consisting of plasmid-borne cpe-genotypes. Analysis of the variable gene pool complemented with the growth studies demonstrate different carbohydrate and amine metabolism in the chromosomal and plasmid-borne cpe-carrying strains, suggesting different epidemiology of the cpe-positive C. perfringens strain groups. Array CGH. Two-color hybridizations on 8x15K Agilent arrays. Eight reference strain hybridizations. Normalization was based on log-ratios against the reference strain. For each sample, 8 normalization factors were calculated, one against each reference hybridization, and the median normalization factor was used. This was repeated for each sample hybridization separately.
Project description:Expression profiling of stably infected primary endothelial cells using a custom tiling microarray. LEC and BEC were infected with rKSHV.219 and selected with puromycin for 2 weeks. Mock infected LEC and BEC served as controls for their infected counterparts. All cells were harvested after 2 weeks of stable infection.
Project description:RNA-seq was employed for comparative analysis of the transcriptomes of both the pathogen and the host in C. perfringens-infected murine muscle lesions. The aim was to identify C. perfringens genes that were induced in the host environment and host signaling cascades that were activated in response to a C. perfringens infection.
Project description:Expression profiling of stably infected primary endothelial cells using a custom tiling microarray. LEC, BEC, HUVEC, and HAEC were infected with rKSHV.219 and selected with puromycin for 2 weeks. Mock infected LEC, BEC, HUVEC, and HAEC served as controls for their infected counterparts. All cells were harvested after 2 weeks of stable infection.
Project description:Transcriptional profiling of C. perfringens 13 strain compared with strain 13∆cpe1786 erm after growth in minimal medium with 0.5 mM cystine.