title: Porcine circovirus type 2 potentiates morbidity of Salmonella enterica serovar Choleraesuis in Cesarean-derived, colostrum-deprived pigs.
abstract: OBJECTIVE
  Porcine circovirus type 2 (PCV2) and Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) are two leading causes of economic loss in the swine industry. Although S. Choleraesuis infection occurs concurrently with PCV2-associated disease in many swine herds, the pathogenesis of concurrent infection with PCV2 and S. Choleraesuis remains largely undefined.
  
  
  OBJECTIVE
  We investigated the interactions between PCV2 and S. Choleraesuis in 20 Cesarean-derived, colostrum-deprived (CDCD) pigs randomly assigned to 4 groups (n=5 per group).
  
  
  METHODS
  Pigs in the dual-infected and PCV2-infected groups were inoculated intranasally with PCV2 at 5 weeks of age, and pigs in the dual-infected and S. Choleraesuis-infected groups were inoculated intranasally with S. Choleraesuis at 7 weeks of age. Pigs in the control group served as uninfected controls.
  
  
  RESULTS
  After S. Choleraesuis inoculation, severe clinical signs, reduction of weight gain, and severe microscopic lung lesions were observed in dual-infected pigs compared to those in other groups. In addition, the pigs in the dual-infected group shed significantly (P=0.002) higher quantities of S. Choleraesuis in feces 12 days after S. Choleraesuis inoculation, and S. Choleraesuis was recovered from more tissues in this group 14 days after S. Choleraesuis inoculation.
  
  
  CONCLUSIONS
  These results indicate that prior PCV2 infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of S. Choleraesuis in infected pigs. Therefore, dual infection of pigs with PCV2 and S. Choleraesuis may increase clinical effects of salmonellosis in the field.
authors.affiliation: Zen-noh Institute of Animal Health, 7 Ohja-machi, Sakura, Chiba 285-0043, Japan. takada-asuka@zennoh.or.jp
authors.forename: A
authors.initials: A
authors.lastname: Takada-Iwao
authors.forename: M
authors.initials: M
authors.lastname: Nakanishi
authors.forename: J
authors.initials: J
authors.lastname: Souma
authors.forename: S
authors.initials: S
authors.lastname: Chikata
authors.forename: Y
authors.initials: Y
authors.lastname: Okuda
authors.forename: Y
authors.initials: Y
authors.lastname: Imai
authors.forename: S
authors.initials: S
authors.lastname: Sato
mesh_terms: D000818:Animals; D057138:Bacterial Shedding; D002585:Cesarean Section / Q000662:veterinary; D018173:Circoviridae Infections / Q000473:pathology / Q000662:veterinary*; D017925:Circovirus / Q000472:pathogenicity; D060085:Coinfection / Q000382:microbiology / Q000473:pathology* / Q000821:virology; D003126:Colostrum; D004279:DNA, Viral / Q000097:blood; D005243:Feces / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000473:pathology*; D019779:Salmonella enterica / Q000472:pathogenicity; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology / Q000473:pathology* / Q000821:virology
chemical_list: D004279:DNA, Viral