A study of the evolution of coxsackievirus A24 variant in Ghana by viral RNA fingerprinting analysis.
ABSTRACT An epidemic of acute haemorrhagic conjunctivitis (AHC) caused by coxsackievirus A24 variant (CA24v) was reported in Accra, Ghana in May 1987. We studied 7 of the viral strains collected from May to November, 1987, by RNA genome fingerprinting. Pairwise comparisons of the oligonucleotide maps showed that genetic similarity among them ranged from between 60.0 to 84.7%. Using base sequence variations deduced from genetic similarity among the isolates, isolation time of the strains and the rate of nucleotide substitution (estimated in a previous paper, Miyamura et al., 1990), we calculated divergence times and constructed a phylogenetic tree. This tree indicated that all the 7 strains had diverged from each other from 11 to 26 months before the AHC epidemic in Accra. CA24v may have been introduced into the country or the neighbouring area, at least, more than two years earlier, i.e. in the early half of 1985.
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ABSTRACT: Picornaviruses have some of the highest nucleotide substitution rates among viruses, but there have been no comparisons of evolutionary rates within this broad family. We combined our own Bayesian coalescent analyses of VP1 regions from four picornaviruses with 22 published VP1 rates to produce the first within-family meta-analysis of viral evolutionary rates. Similarly, we compared our rate estimates for the RNA polymerase 3D(pol) gene from five viruses to four published 3D(pol) rates. Both a structural and a nonstructural gene show that enteroviruses are evolving, on average, a half order of magnitude faster than members of other genera within the Picornaviridae family.Journal of Virology 05/2011; 85(15):7942-7. · 5.08 Impact Factor
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ABSTRACT: The complete nucleotide sequence was determined for the cDNAs that represent the RNA genome of the standard strain of a variant of coxsackievirus A24, the EH24/70, one of the agents causing acute hemorrhagic conjunctivitis. The genome is 7461 nucleotide long and is polyadenylated at the 3'-end terminus. Following a 750-nucleotide 5'-noncoding region, there was a long open reading frame of 6642 nucleotides, which serve to encode a viral polyprotein consisting of 2214 amino acids. Comparison of the deduced amino acid sequence of the polyprotein with those of known enteroviruses allowed us to predict the possible cleavage sites. The overall structure and the organization of the RNA genome is typical for an enterovirus. Based on the similarity of the nucleotide sequence of the 5' and 3' noncoding regions, together with the amino-acid sequence of the encoded proteins, EH24/70 appeared to be closely related to polioviruses and coxsackievirus A21.Virus Genes 05/1992; 6(2):149-58. · 1.84 Impact Factor
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ABSTRACT: Variations in the nucleotide sequence of 3 C proteinase of coxsackievirus A 24 variant (CA 24 v) were analyzed to define the route of transmission and spread of the virus which was introduced to Japan on three separate occasions, 1985-86, 1988, and 1989. The nucleotide sequences of isolates from the same year's outbreak in Japan were identical or closely related, while the isolates from different outbreaks were less closely related to one another than to those from other countries in the same year. All Japanese isolates from Okinawa and other prefectures in 1985 and 1986 were closely related to the Taiwan strains in those same years, indicating common-source outbreaks. Two 1988 isolates from Chiba Prefecture, Japan, were closely related to those from Singapore in 1987, China in 1988 and Hong Kong in 1988. All seven Japanese isolates from Chiba Prefecture in 1989 comprised a group together with the Taiwan and Singapore strains in 1988. The results indicate that CA 24 v was introduced into Japan on each occasion from the outside. Furthermore, in contrast to the explosive epidemics in Okinawa Prefecture in 1985 and 1986, the virus which was repeatedly introduced to other areas in Japan did not circulate endemically, and disappeared within a short time.Archives of Virology 02/1992; 126(1-4):179-93. · 2.28 Impact Factor