title: Concurrent highly pathogenic porcine reproductive and respiratory syndrome virus infection accelerates Haemophilus parasuis infection in conventional pigs.
abstract: This study was aimed at determining the effect of highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) on Haemophilus parasuis (HPS) in co-infection. A quantitative real-time PCR targeting infB gene, which is conserved among different HPS serotypes, was developed to improve the accuracy and speed of the detection of HPS. A total of 32 four-week-old conventional pigs were distributed randomly into four groups: pigs in group I were intranasally infected with HP-PRRSV first, and were then intraperitoneally inoculated with HPS on 5 days after HP-PRRSV infection; pigs in group II were intranasally inoculated with HP-PRRSV alone; pigs in group III were intraperitoneally inoculated with HPS alone; pigs in group IV were intraperitoneally inoculated with physiological saline. The amount of HPS in serum on 0, 3, 6, 9 and 12 days post-inoculation (dpi) with HPS were detected using the established quantitative real-time PCR. Clinical signs, pathological changes and histopathological lesions were observed. The amount of HPS in serum reached 10(6)copies/μl at 3 dpi with HPS in pigs of group I, while it arrived 10(5.7)copies/μl at 9 dpi with HPS in pigs of group III. The HPS loads in hearts and lungs were much higher than in other tissues. The study showed that HP-PRRSV was able to accelerate HPS infection and loads.
authors.affiliation: Shandong Normal University, Jinan, People's Republic of China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Yu
authors.forename: Jiaqiang
authors.initials: J
authors.lastname: Wu
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lihui
authors.initials: L
authors.lastname: Guo
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Cong
authors.forename: Yijun
authors.initials: Y
authors.lastname: Du
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Wenbo
authors.initials: W
authors.lastname: Sun
authors.forename: Jianli
authors.initials: J
authors.lastname: Shi
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
authors.forename: Feifei
authors.initials: F
authors.lastname: Yin
authors.forename: Dapeng
authors.initials: D
authors.lastname: Wang
authors.forename: Pengwei
authors.initials: P
authors.lastname: Zhao
authors.forename: Jinbao
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D060085:Coinfection; D006192:Haemophilus Infections / Q000097:blood / Q000150:complications* / Q000382:microbiology / Q000473:pathology* / Q000821:virology; D044137:Haemophilus parasuis / Q000502:physiology; D008168:Lung / Q000382:microbiology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000473:pathology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology / Q000473:pathology* / Q000821:virology