title: Virulence and draft genome sequence overview of multiple strains of the swine pathogen Haemophilus parasuis.
abstract: Haemophilus parasuis is the cause of Glässer's disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Investigation of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to subclinical carriage. To identify differences in genotype that could account for virulence phenotypes, we established the virulence of, and performed whole genome sequence analysis on, 11 H. parasuis strains. Virulence was assessed by evaluating morbidity and mortality following intranasal challenge of Caesarean-derived, colostrum-deprived (CDCD) pigs. Genomic DNA from strains Nagasaki (serotype 5), 12939 (serotype 1), SW140 (serotype 2), 29755 (serotype 5), MN-H (serotype 13), 84-15995 (serotype 15), SW114 (serotype 3), H465 (serotype 11), D74 (serotype 9), and 174 (serotype 7) was used to generate Illumina paired-end libraries for genomic sequencing and de novo assembly. H. parasuis strains Nagasaki, 12939, SH0165 (serotype 5), SW140, 29755, and MN-H exhibited a high level of virulence. Despite minor differences in expression of disease among these groups, all pigs challenged with these strains developed clinical signs consistent with Glässer's disease between 1-7 days post-challenge. H. parasuis strains 84-15995 and SW114 were moderately virulent, in that approximately half of the pigs infected with each developed Glässer's disease. H. parasuis strains H465, D74, and 174 were minimally virulent or avirulent in the CDCD pig model. Comparative genomic analysis among strains identified several noteworthy differences in coding regions. These coding regions include predicted outer membrane, metabolism, and pilin or adhesin related genes, some of which likely contributed to the differences in virulence and systemic disease observed following challenge. These data will be useful for identifying H. parasuis virulence factors and vaccine targets.
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa, United States of America.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Brockmeier
authors.affiliation: Ruminant Diseases and Immunology Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa, United States of America.
authors.forename: Karen B
authors.initials: KB
authors.lastname: Register
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Kuehn
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa, United States of America.
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Nicholson
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa, United States of America.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Loving
authors.affiliation: Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa, United States of America.
authors.forename: Darrell O
authors.initials: DO
authors.lastname: Bayles
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa, United States of America.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Shore
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Phillips
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology; D000818:Animals; D000831:Animals, Newborn; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology; D002585:Cesarean Section; D002874:Chromosome Mapping; D036781:Fimbriae Proteins / Q000235:genetics / Q000276:immunology; D016680:Genome, Bacterial; D006192:Haemophilus Infections / Q000382:microbiology / Q000401:mortality / Q000473:pathology* / Q000662:veterinary*; D044137:Haemophilus parasuis / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity*; D059014:High-Throughput Nucleotide Sequencing; D012703:Serotyping; D012720:Severity of Illness Index; D016019:Survival Analysis; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology / Q000401:mortality / Q000473:pathology*; D014774:Virulence
chemical_list: D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D036781:Fimbriae Proteins