ABSTRACT
The differentiation of the vaccine or wild origin of Poliovirus at the laboratory is an important step towards the process of the poliomyelitis eradication. We report herein the results obtained from Poliovirus types 3 and 2, isolated in Madagascar in 1997 and 2002 from healthy children and cases of acute flaccid paralysis, respectively. The technique used is based on the amplification of genome (RT-PCR), followed by Restriction Fragment Length Polymorphism assay (RFLP), performed in 3 different regions of the genome. In the capsid region (VP3-VP1 and VP1-2A), RFLP analysis allowed us to differentiate without ambiguity the wild or vaccine origin of the Poliovirus type 3, and to identify Vaccine-Derived Poliovirus (VDPV) type 2. In the noncapsid region, including the RNA polymerase and 3' non coding region (3Dpol-3' NTR), the VDPV were found to be recombinant with other Enteroviruses. These results confirm that RFLP assay is a reliable tool for intratypic differentiation and to study the genetic drift and recombination of Poliovirus.
Subject(s)
Genetic Variation/genetics , Poliomyelitis/virology , Poliovirus/genetics , Polymorphism, Restriction Fragment Length , Reverse Transcriptase Polymerase Chain Reaction/methods , Capsid Proteins/genetics , Case-Control Studies , Child , DNA, Viral/analysis , DNA, Viral/genetics , DNA-Directed RNA Polymerases/genetics , Genetic Drift , Genome, Viral , Humans , Madagascar/epidemiology , Poliomyelitis/epidemiology , Poliovirus/classification , Poliovirus Vaccine, Oral/adverse effects , RNA, Untranslated/genetics , RNA, Viral/analysis , RNA, Viral/genetics , Recombination, Genetic/genetics , Reverse Transcriptase Polymerase Chain Reaction/standardsABSTRACT
"New method for molecular typing of human enteroviruses: characterization of ""untypeable"" strains isolated in Madagascar"" : Enteroviruses; members of the family icornaviridae;are responsible for a wide variety of diseases and represent a major public health hazard. Typing of non polio enterovirus (NPEV) infection is traditionally based on a serum neutralization assay. However; this method is time-consuming; labor-intensive; expensive; and may fail to identify antigenic variation. A new molecular typing involving partial sequencing of the genome has been recently developed. In this study; 46 NPEV strains were analyzed; including 37 antigenicaly ""untypeable"" viruses. Partial sequencing of the C-end of the viral capsid protein VP1 and pairwise identity with the prototype strains allow us to assign a serotype for all ""untypeable"" viruses. The result show a large number and wide variety of Coxsackieviruses A which belong to the HEV-C species and also Echoviruses and Coxsackieviruses B of the HEV-B species. This method may be useful to identify all NPEV serotypes in Madagascar and to assess the possible impact of circulating NPEV populations; as we enter the final stage of poliomyelitis eradication."
Subject(s)
Enterovirus , Molecular Sequence DataABSTRACT
"Genetic variability of Poliovirus : typing of strains isolated in Madagascar by Restriction Fragment Length Polymorphism (RFLP) assay"". The differentiation of the vaccineor wild origin of Poliovirus at the laboratory is an important step towards the process of the poliomyelitis eradication. We report herein the results obtained from Poliovirus types 3 and 2; isolated in Madagascar in 1997 and 2002 from healthy children and cases of acute flaccid paralysis; respectively. The technique used is based on the amplification of genome (RT-PCR); followed by Restriction Fragment Length Polymorphism assay (RFLP); performed in 3 different regions of the genome. In the capsid region (VP3-VP1 and VP1-2A); RFLP analysis allowed us to differentiate without ambiguity the wild or vaccine origin of the Poliovirus type 3; and to identify Vaccine-Derived Poliovirus (VDPV) type 2. In the noncapsid region; including the RNA polymerase and 3' non coding region (3Dpol-3' NTR); the VDPV were found to be recombinant with other Enteroviruses. These results confirm that RFLP assay is a reliable tool for intratypic differentiation and to study the genetic drift and recombination of Poliovirus."
Subject(s)
Poliovirus , VaccinationABSTRACT
Enteroviruses, members of the family Picornaviridae, are responsible for a wide variety of diseases and represent a major public health hazard. Typing of non polio enterovirus (NPEV) infection is traditionally based on a serum neutralization assay. However, this method is time-consuming, labor-intensive, expensive, and may fail to identify antigenic variation. A new molecular typing involving partial sequencing of the genome has been recently developed. In this study, 46 NPEV strains were analyzed, including 37 antigenicaly "untypeable" viruses. Partial sequencing of the C-end of the viral capsid protein VP1 and pairwise identity with the prototype strains allow us to assign a serotype for all "untypeable" viruses. The results show a large number and wide variety of Coxsackieviruses A which belong to the HEV-C species and also Echoviruses and Coxsackieviruses B of the HEV-B species. This method may be useful to identify all NPEV serotypes in Madagascar and to assess the possible impact of circulating NPEV populations, as we enter the final stage of poliomyelitis eradication.
