9Galina L,Pijoan C,Sitjar M,et al.Interaction between Streptococ-cus suis serotype 2 and porcine reproductive and respiratorysyndrome virus in specific pathogen-free piglets[J].The Veteri-nary Rrcord,1999,134(3):60-64.
10Feng W H,Laster S M,Tompkins M,et al.In Utero Infection byPorcine Reproductive and Respiratory Syndrome Virus is Sufficientto Increase Susceptibility of Piglets to Challenge by Streptacaccussuis Type Ⅱ[J].Journal of Virology,2001,75(10):4889-4895.
2Halbur P.Efficacy of antimicrobial treatment and vaccinationregimens to control of Porcine Reproductive and RespiratorySydrome virus and Streptococcus suis coinfection of nurserypigs. Journal of Clinical Microbiology . 2000
3Yoon K J,Wu L L,Zimmerman J J,et al.Field isolates of porcine reproductive and respiratory syndrome virus (PRRSV) vary in their susceptibility to antibody-dependent enhancement (ADE) of infection. Veterinary Microbiology . 1997