title: Genetic analysis of the S1 gene of 4/91 type infectious bronchitis virus isolated in Japan.
abstract: S1 gene sequences for infectious bronchitis virus (IBV) strains of the 4/91 genotype (commonly called 793B) isolated from field outbreaks in Japan were analyzed to ascertain the relationship to 4/91 vaccine strain. Three field isolates (JP/Wakayama/2003, JP/Iwate/2005 and JP/Saitama/2006) from flocks not immunized with a 4/91 type live IBV vaccine and one isolate (JP/Wakayama-2/2004) from a flock immunized with a 4/91 type live vaccine were examined. The amino acid identities among JP/Wakayama/2003, JP/Iwate/2005 and JP/Saitama/2006 were about 98%, whereas the identities to the 4/91 vaccine strain and JP/Wakayama-2/2004 were about 90%. Three of the field isolates, JP/Wakayama/2003, JP/Iwate/2005 and JP/Saitama/2006, were classified into a cluster closely related to French and Spanish isolates, but different from the cluster including the vaccine and JP/Wakayama-2/2004. These results indicate that JP/Wakayama/2003, JP/Iwate/2005 and JP/Saitama/2006 were derived from foreign field isolates, but not from the vaccine strain. On the other hand, the S1 gene of JP/Wakayama-2/2004 revealed high sequence similarity with that of the 4/91 vaccine strain and appeared to be a vaccine-like virus derived from a vaccine. The field isolates of 4/91 genotype IBV could be distinguished from other genotypes by using the BalI and Pst I enzymes in addition to the polymerase chain reaction (PCR) -restriction fragment length polymorphism (RFLP) methods of Mase et al. [16] using Hae II and EcoR I enzymes. Furthermore, the 4/91 vaccine strain and vaccine-like isolate (JP/Wakayama-2/2004) could be differentiated from the other field isolates by Bgl II digestion. This method, therefore, would assist in identification of field isolates of the 4/91 genotype as outbreaks of IBV in vaccinated flocks.
authors.affiliation: National Veterinary Assay Laboratory, Tokyo, Japan. shimayo@nval.go.jp
authors.forename: Yohko
authors.initials: Y
authors.lastname: Shimazaki
authors.forename: Yuuko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Makiko
authors.initials: M
authors.lastname: Harada
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Seki
authors.forename: Yorifumi
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Masaharu
authors.initials: M
authors.lastname: Fukuda
authors.forename: Eiichi
authors.initials: E
authors.lastname: Honda
authors.forename: Shoko
authors.initials: S
authors.lastname: Suzuki
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens; D018352:Coronavirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D004196:Disease Outbreaks / Q000662:veterinary*; D014644:Genetic Variation; D001351:Infectious bronchitis virus / Q000235:genetics* / Q000302:isolation & purification; D007564:Japan / Q000453:epidemiology; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D011201:Poultry Diseases / Q000453:epidemiology / Q000821:virology*; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D013047:Specific Pathogen-Free Organisms; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology
chemical_list: D008562:Membrane Glycoproteins; D012367:RNA, Viral; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; D014765:Viral Vaccines