title: Synergistic pathogenicity in sequential coinfection with Mycoplasma hyorhinis and porcine circovirus type 2.
abstract: To investigate the synergistic pathogenicity of Mycoplasma hyorhinis (Mhr) with porcine circovirus type 2 (PCV2), thirty 35-day-old piglets were randomly distributed to six groups (n=5 each): Mhr/PCV2 (group 1, inoculated with Mhr and PCV2 1 week later), PCV2/Mhr (group 2, inoculated with PCV2 and Mhr 1 week later), Mhr-PCV2 (group 3, inoculated with PCV2 and Mhr concurrently), singular PCV2 group (group 4), singular Mhr group (group 5), and a uninfected control group (group 6). Mild transient lethargy, fever, coughing, inappetence, and decreased daily weight gain were observed in all dual-infected groups and the singular Mhr-infected group. There were significantly higher levels of PCV2 and Mhr antibodies, larger amounts and wider range of tissue distribution of PCV2 antigens and nucleic acids in the dual-infected groups compared to the single-infected and control groups. PCV2 and Mhr dual-infection resulted in significantly more severe macroscopic and microscopic lung lesions and wider PCV2 DNA distribution compared with piglets infected with PCV2 alone. Cytokine detection showed a significant change in tumor necrosis factor-α, interleukin-2, and interleukin-6 levels in the infected groups, especially in the Mhr-PCV2 group, compared with the control group. Hence, Mhr potentiated the severity of PCV2-associated lung lesions, increased the amount and distribution of PCV2 DNA in tissues, and increased the incidence of porcine respiratory disease.
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Dongjie
authors.initials: D
authors.lastname: Chen
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Liping
authors.initials: L
authors.lastname: Huang
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Sun
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Du
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China.
authors.forename: Hongli
authors.initials: H
authors.lastname: Wu
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China. Electronic address: lcm@hvri.ac.cn.
authors.forename: Changming
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D002460:Cell Line; D018173:Circoviridae Infections / Q000150:complications / Q000473:pathology / Q000662:veterinary*; D017925:Circovirus / Q000145:classification*; D060085:Coinfection; D007668:Kidney / Q000166:cytology; D008168:Lung / Q000473:pathology; D008171:Lung Diseases / Q000382:microbiology / Q000473:pathology / Q000821:virology; D009175:Mycoplasma Infections / Q000150:complications / Q000473:pathology / Q000662:veterinary*; D045790:Mycoplasma hyorhinis; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology* / Q000473:pathology / Q000821:virology*
keywords: Mycoplasma hyorhinis; Porcine circovirus type 2; Synergistic pathogenicity