title: Intertypic genomic rearrangements of poliovirus strains in vaccinees.
abstract: In vivo intertypic RNA recombination has previously been observed in excreted type 3 poliovirus isolates from a normal asymptomatic primary vaccinee. This study examines isolates from additional primary vaccinees to determine whether intertypic recombination is a general occurrence in excreted polioviruses. T1 RNase oligonucleotide finger-printing and limited dideoxy primer extension RNA sequencing demonstrated no evidence of intertypic recombination among type 1 or type 2 excreted strains. However, vaccinees excreting type 3 strains for long periods of time eventually produced recombinant strains involving either type 1 or type 2 poliovirus. Moreover, a characteristic time course of appearance of excreted type 3 intertypic recombinant polioviruses was established. Type 3/type 1 and type 3/type 2 recombinant strains appeared at Days 10-11 with a single crossover site in the gene for nonstructural protein 2C. Type 3/type 2/type 3 complex recombinant strains with an additional crossover site in the polymerase gene replaced type 3/type 2 strains at approximately Day 28. A significant portion of the genome of the type 3 Sabin vaccine strain is thus replaced during long-term excretion by vaccinees, and the appearance of some genomic arrangements coincided with a base deletion at the 3' terminus.
authors.affiliation: Division of Virology, National Institute for Biological Standards and Control, Herts, United Kingdom.
authors.forename: N
authors.initials: N
authors.lastname: Cammack
authors.forename: A
authors.initials: A
authors.lastname: Phillips
authors.forename: G
authors.initials: G
authors.lastname: Dunn
authors.forename: V
authors.initials: V
authors.lastname: Patel
authors.forename: P D
authors.initials: PD
authors.lastname: Minor
mesh_terms: D005243:Feces / Q000382:microbiology; D006801:Humans; D009710:Nucleotide Mapping; D017955:Poliovirus / Q000145:classification / Q000235:genetics*; D011055:Poliovirus Vaccine, Oral / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic; D013997:Time Factors; D014611:Vaccination
chemical_list: D011055:Poliovirus Vaccine, Oral; D012367:RNA, Viral