Molecular identification of Saint Louis encephalitis virus genotype IV in Colombia

Abstract

Saint Louis encephalitis virus (SLEV) is a member of the Japanese-encephalitis virus serocomplex of the genus Flavivirus. SLEV is broadly distributed in the Americas and the Caribbean Islands, where it is usually transmitted by mosquitoes of the genus Culex and primarily to birds and mammalian-hosts. Humans are occasionally infected by the virus and are dead-end hosts. SLEV causes encephalitis in temperate regions, while in tropical regions of the Americas, several human cases and a wide biological diversity of SLEV-strains have been reported. The phylogenetic analysis of the envelope (E) protein genes indicated eight-genotypes of SLEV with geographic overlap. The present paper describes the genotyping of two SLEV viruses detected in mosquito-pools collected in northern Colombia (department of Cordoba). We used reverse transcription-polymerase chain reaction to amplify a fragment of theE-gene to confirm the virus identity and completeE-gene sequencing for phylogenetic analysis and genotyping of the two-SLEV viruses found circulating in Córdoba. This is the first report of SLEV genotype IV in Colombia (Córdoba) in mosquitoes from a region of human inhabitation, implicating the risk of human disease due to SLEV infection. Physicians should consider SLEV as a possible aetiology for undiagnosed febrile and neurologic syndromes among their patients who report exposure to mosquito-bites.

Molecular Clock and Phylogeny ofAnophelesspecies of the subgenusNyssorhynchus(Diptera: Culicidae)

“…The inference of separation times for the species of the subgenus Nyssorhynchus of Anopheles was calculated using a relaxed Bayesian molecular clock (uncorrelated & log-normal) and a “Yule-Calibrated” speciation process (Hoyos et al, 2015a; Hoyos et al 2015b). Topology of the tree, minimum and maximum intervals of the age of the nodes, and age restrictions by secondary and fossil data were used to define the priors.…”

“…The identification of species is essential for vector incrimination, the measurement of epidemiological risk and the development of management programs for malaria (Sinka, 2010); the focus of these works are guided to mosquitoes belonging to the genus Anopheles , which contains all known malaria vectors, with a significant number of representatives considered complex species (Foster, 2013), these are considered morphologically indistinguishable and in other cases phenotypic plasticity makes identification difficult, due to similarity with closely related species (Sallum, 2000). In these cases of taxonomic complexity, only approaches with markers and molecular tools allow to resolve the identity, relationships between species and vector incrimination (Porter & Collins, 1991, Paskewitz, 1993, Cornel, 1996, Cywinska, 2006, Marelli, 2006, Zapata, 2007, Hoyos-López et al 2012a, Hoyos-López et al 2012b, Hoyos et al 2015a, Hoyos et al 2015b, Hoyos et al 2015c, Hoyos et al 2016, Hoyos et al 2017).…”

Phylogenetic Analysis of St. Louis Encephalitis Virus within Two Southwestern United State Counties: a case for a bulk introduction event into the southwest United States

“…The maximum-likelihood tree was constructed using IQ-TREE with 1000 bootstraps iterations [28] [28,29] [30] . The tree was rooted using the two strains of SLEV (JQ957869.1 and JQ957870.1) detected in Columbia in 2008 as described by Hoyos-Lopez et al [31] .…”

Phylogenetic analysis of Dengue-2 serotypes circulating in mangroves in Northern Cordoba, Colombia

“…aegypti 6,9 facilitated new routes of entry and the establishment of novel DENV strains. Therefore, it is likely that mangrove ecosystems in Northern of Cordoba served as migratory zones for bird fauna 10 , and the identification of evolutionary variants of St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) that belong to the same clade as the strains isolated from mosquitoes/birds/humans of Texas and Panama supports this hypothesis 14,15 . Enzootic cycle of Dengue virus is unlikely because of the absence of adults and larvae of Ae.…”