RESUMEN
Five representatives from a collection of 21 Sabin type 2-like poliovirus strains isolated from paralytic poliomyelitis cases in two regions of the USSR have been subjected to limited nucleotide sequencing. All proved to be intertypic recombinants having the genes encoding capsid proteins of Sabin 2 origin and a 3'-end portion of the genome derived from either type 1 (3 isolates) or type 3 (2 isolates) Sabin strains. The crossover points in all the 5 genomes have been mapped to different loci of the P3 region. At least 6 additional isolates from the same collection (and 2 isolates from healthy contacts), appeared to have a type 2/type 1 recombinant genome, as judged by oligonucleotide mapping. The biological significance of frequent occurrence of recombinants among field isolates of vaccine-related strains is discussed.
Asunto(s)
Poliomielitis/genética , Vacuna Antipolio Oral/efectos adversos , Poliovirus/genética , Recombinación Genética , Serotipificación , Secuencia de Bases , Preescolar , Mapeo Cromosómico , Heces/microbiología , Genoma Viral , Humanos , Lactante , Datos de Secuencia Molecular , Mutagénesis , Mapeo Nucleótido , ARN Viral/genética , U.R.S.S.RESUMEN
Eleven virus strains isolated from poliomyelitis patients in Moscow in 1973-1986 were analyzed by the method of oligonucleotide mapping of RNA. The genome of the isolates showed considerable similarity to the genomes of Sabin's vaccine strains and mainly to the vaccine strain of antigenic type 2. The conclusion was made that the sporadic cases of poliomyelitis registered in this region were etiologically linked with the vaccine strains of poliomyelitis virus. Only in one case the disease appeared in the recipient of the vaccine, in all other cases the patients were infected through contacts.
Asunto(s)
Poliomielitis/epidemiología , Poliovirus/genética , Población Urbana/estadística & datos numéricos , Anticuerpos Antivirales/análisis , Secuencia de Bases , Preescolar , Heces/microbiología , Genes Virales/genética , Humanos , Lactante , Datos de Secuencia Molecular , Moscú/epidemiología , Oligonucleótidos/genética , Poliomielitis/microbiología , Poliovirus/inmunología , Poliovirus/aislamiento & purificación , Estudios RetrospectivosRESUMEN
Oligonucleotide maps of some poliovirus type 2 strains isolated from polio cases, while being clearly related to that of the Sabin vaccine type 2 strain, exhibited, nevertheless, marked differences from the reference (vaccine) map. Several large oligonucleotides derived from 4 such strains were subjected to enzymatic sequencing. The results strongly suggest that all of them were intertypic recombinants between the Sabin strains. The 5'-parts of the genomes of these strains were derived from the type 2 vaccine whereas the 3'-parts were of type 1 (in 2 strains) or type 3 (in other 2 strains) origin.
Asunto(s)
Poliomielitis/microbiología , Vacuna Antipolio Oral , Poliovirus/aislamiento & purificación , ARN Viral/genética , Recombinación Genética , Secuencia de Bases , Preescolar , Humanos , Lactante , Datos de Secuencia Molecular , Poliovirus/genética , Poliovirus/inmunologíaRESUMEN
Oligonucleotide mapping of the RNA genome was applied for analysis of poliovirus clinical isolates in Byelorussia in 1967-1985. All the maps have been clearly shown to resemble the reference maps of the corresponding vaccine strains. Examination of the oligonucleotide maps of poliovirus isolates provides a measure of distribution of some of the mutations over the viral genome.