title: Genetic Characterization of ExPEC-Like Virulence Plasmids among a Subset of NMEC.
abstract: Neonatal Meningitis Escherichia coli (NMEC) is one of the most common causes of neonatal bacterial meningitis in the US and elsewhere resulting in mortality or neurologic deficits in survivors. Large plasmids have been shown experimentally to increase the virulence of NMEC in the rat model of neonatal meningitis. Here, 9 ExPEC-like plasmids were isolated from NMEC and sequenced to identify the core and accessory plasmid genes of ExPEC-like virulence plasmids in NMEC and create an expanded plasmid phylogeny. Results showed sequenced virulence plasmids carry a strongly conserved core of genes with predicted functions in five distinct categories including: virulence, metabolism, plasmid stability, mobile elements, and unknown genes. The major functions of virulence-associated and plasmid core genes serve to increase in vivo fitness by adding multiple iron uptake systems to the genetic repertoire to facilitate NMEC's survival in the host's low iron environment, and systems to enhance bacterial resistance to host innate immunity. Phylogenetic analysis based on these core plasmid genes showed that at least two lineages of ExPEC-like plasmids could be discerned. Further, virulence plasmids from Avian Pathogenic E. coli and NMEC plasmids could not be differentiated based solely on the genes of the core plasmid genome.
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Bryon A
authors.initials: BA
authors.lastname: Nicholson
authors.affiliation: Department of Chemistry, College of Liberal Arts and Sciences, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Aaron C
authors.initials: AC
authors.lastname: West
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Paul
authors.initials: P
authors.lastname: Mangiamele
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Nicolle
authors.initials: N
authors.lastname: Barbieri
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Wannemuehler
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Nolan
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Logue
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, 1802 University Blvd, Iowa State University, Ames, Iowa, 50011, United States of America.|Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P. R. China.
authors.forename: Ganwu
authors.initials: G
authors.lastname: Li
mesh_terms: D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000382:microbiology*; D020814:Meningitis, Escherichia coli / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA