title: Plasmid Characterization and Chromosome Analysis of Two netF+ Clostridium perfringens Isolates Associated with Foal and Canine Necrotizing Enteritis.
abstract: The recent discovery of a novel beta-pore-forming toxin, NetF, which is strongly associated with canine and foal necrotizing enteritis should improve our understanding of the role of type A Clostridium perfringens associated disease in these animals. The current study presents the complete genome sequence of two netF-positive strains, JFP55 and JFP838, which were recovered from cases of foal necrotizing enteritis and canine hemorrhagic gastroenteritis, respectively. Genome sequencing was done using Single Molecule, Real-Time (SMRT) technology-PacBio and Illumina Hiseq2000. The JFP55 and JFP838 genomes include a single 3.34 Mb and 3.53 Mb chromosome, respectively, and both genomes include five circular plasmids. Plasmid annotation revealed that three plasmids were shared by the two newly sequenced genomes, including a NetF/NetE toxins-encoding tcp-conjugative plasmid, a CPE/CPB2 toxins-encoding tcp-conjugative plasmid and a putative bacteriocin-encoding plasmid. The putative beta-pore-forming toxin genes, netF, netE and netG, were located in unique pathogenicity loci on tcp-conjugative plasmids. The C. perfringens JFP55 chromosome carries 2,825 protein-coding genes whereas the chromosome of JFP838 contains 3,014 protein-encoding genes. Comparison of these two chromosomes with three available reference C. perfringens chromosome sequences identified 48 (~247 kb) and 81 (~430 kb) regions unique to JFP55 and JFP838, respectively. Some of these divergent genomic regions in both chromosomes are phage- and plasmid-related segments. Sixteen of these unique chromosomal regions (~69 kb) were shared between the two isolates. Five of these shared regions formed a mosaic of plasmid-integrated segments, suggesting that these elements were acquired early in a clonal lineage of netF-positive C. perfringens strains. These results provide significant insight into the basis of canine and foal necrotizing enteritis and are the first to demonstrate that netF resides on a large and unique plasmid-encoded locus.
authors: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Iman
authors: I
authors: Mehdizadeh Gohari
authors: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Andrew M
authors: AM
authors: Kropinski
authors: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Scott J
authors: SJ
authors: Weese
authors: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Valeria R
authors: VR
authors: Parreira
authors: Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, CSB 101E, Canada.
authors: Ashley E
authors: AE
authors: Whitehead
authors: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Patrick
authors: P
authors: Boerlin
authors: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: John F
authors: JF
authors: Prescott
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics*; D003015:Clostridium Infections / Q000382:microbiology / Q000662:veterinary*; D003016:Clostridium perfringens / Q000235:genetics; D004285:Dogs / Q000382:microbiology*; D004751:Enteritis / Q000382:microbiology / Q000662:veterinary*; D056426:Genetic Loci / Q000235:genetics; D023281:Genomics; D006736:Horses / Q000382:microbiology*; D010957:Plasmids / Q000235:genetics*; D017421:Sequence Analysis; D013045:Species Specificity
chemical_list: D001427:Bacterial Toxins