Genome Sequence Analysis of Dengue Virus 1 Isolated in Key West, Florida

Dongyoung Shin,Chelsea T Smartt,Barry W Alto,David J Bettinardi,Stephanie L Richards

doi:10.1371/journal.pone.0074582

Dongyoung Shin, Chelsea T Smartt + Show 3 more

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https://doi.org/10.1371/journal.pone.0074582

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Abstract

Dengue virus (DENV) is transmitted to humans through the bite of mosquitoes. In November 2010, a dengue outbreak was reported in Monroe County in southern Florida (FL), including greater than 20 confirmed human cases. The virus collected from the human cases was verified as DENV serotype 1 (DENV-1) and one isolate was provided for sequence analysis. RNA was extracted from the DENV-1 isolate and was used in reverse transcription polymerase chain reaction (RT-PCR) to amplify PCR fragments to sequence. Nucleic acid primers were designed to generate overlapping PCR fragments that covered the entire genome. The DENV-1 isolate found in Key West (KW), FL was sequenced for whole genome characterization. Sequence assembly, Genbank searches, and recombination analyses were performed to verify the identity of the genome sequences and to determine percent similarity to known DENV-1 sequences. We show that the KW DENV-1 strain is 99% identical to Nicaraguan and Mexican DENV-1 strains. Phylogenetic and recombination analyses suggest that the DENV-1 isolated in KW originated from Nicaragua (NI) and the KW strain may circulate in KW. Also, recombination analysis results detected recombination events in the KW strain compared to DENV-1 strains from Puerto Rico. We evaluate the relative growth of KW strain of DENV-1 compared to other dengue viruses to determine whether the underlying genetics of the strain is associated with a replicative advantage, an important consideration since local transmission of DENV may result because domestic tourism can spread DENVs.

Highlights

Dengue virus (DENV, Family Flaviviridae, genus Flavivirus) is transmitted to humans through mosquito bites and dengue is epidemic and endemic in tropical and subtropical regions [1]
Key West (KW) (DENV-1) isolates in Vero cell since DENV is endemic in Puerto Rico (PR) and there is potential for importation of human cases into FL (Figure 1)
Dengue virus is endemic in PR and there is potential for importation of human cases into FL

Summary

Introduction

Dengue virus (DENV, Family Flaviviridae, genus Flavivirus) is transmitted to humans through mosquito bites and dengue is epidemic and endemic in tropical and subtropical regions [1]. The Americas have seen an increase in human cases of dengue in recent years [2][5] where all four DENV serotypes are prevalent [2][6]. Nicaragua (NI) and Mexico are dengue endemic areas and both are in the same Central America/ Mexico sub-region, as defined by the Pan America Health Organization (PAHO) [7]. Dengue cases in the Central America/Mexico region showed an increase from 1980 to 2007 [2]. Puerto Rico (PR) is included in the Hispanic Caribbean region as defined by PAHO [7] and dengue outbreaks were reported from 1963–1998 [9]. All four serotypes co-circulate in PR, DENV- 2 and DENV- 3 were the serotypes primarily detected during the outbreak in 2007 [10][11]

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