Isolation and genomic characterization of Culex theileri flaviviruses in field-collected mosquitoes from Turkey

Vector surveillance for the arthropod-borne infections has resulted in the isolation of a growing number of novel viruses, including several flavivirus strains that exclusively replicate in insects. This report describes the isolation and genomic characterization of four insect-specific flaviviruses frommosquitoes, previously collected from various locations in Turkey. C6/36 Aedes albopictus and Vero cell lines were inoculated with mosquito pools. On C6/36 cells, mild cytopathic effects, characterized as rounding and detachment, were observed in four pools that comprised female Culex theileri mosquitoes. Complete (3 isolates, 10,697 nucleotides) or near-complete (1 isolate, 10,452 nucleotides) genomic characterization was performed in these culture supernatants via next generation sequencing. All strains demonstrated high genetic similarities, with over 99% identity match on nucleotide and amino acid alignments, revealing them to be different isolates of the same virus. Sequence comparisons identified the closest relative to be the Culex theileri flavivirus (CTFV) strains, originally characterized in Portugal. Phylogenetic analyses demonstrated that the isolates remained distinct as a cluster but formed amonophyletic group with CTFV strains, and shared a common ancestor with Quang Binh or related Culex flaviviruses. The organization of the viral genome was consistent with the universal flavivirus structure and stem-loops; conserved motifs and imperfect tandem repeats were identified in the non-coding ends of the viral genomes. A potential ribosomal shifting site, resulting in the translation of an additional reading frame, was detected. The deduced viral polyprotein comprised 3357 amino acids and was highly-conserved. Amino acid variations, presumably associated with adaptive environmental pressures, were identified. These isolates comprise the first fully characterized insect-specific flaviviruses in Turkey. Their impact on West Nile virus circulation, which is also endemic in the study region, remains to be explored. (C) 2016 Elsevier B.V. All rights reserved.Armed Forces Health Surveillance Center, Global Emerging Infections Surveillance and Response System (AFHSC-GEIS), United States [W81XWH-11-2-0174]; Georg Forster Research Fellowship (HERMES) for Experienced Researchers by Alexander von Humboldt Foundation; National Research Council (NRC) Research Associateship Award at the Walter Reed Army Institute of ResearchThis study was partially supported by The Armed Forces Health Surveillance Center, Global Emerging Infections Surveillance and Response System (AFHSC-GEIS), United States (W81XWH-11-2-0174) (with Yvonne-Marie Linton as the principal investigator). KE is a recipient of the Georg Forster Research Fellowship (HERMES) for Experienced Researchers by the Alexander von Humboldt Foundation, 2015. This manuscript was prepared whilst YML held a National Research Council (NRC) Research Associateship Award at the Walter Reed Army Institute of Research. This research was performed in part under a Memorandum of Understanding between the Walter Reed Army Institute of Research and the Smithsonian Institution, with institutional support provided by both organizations. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The material to be published reflects the views of the authors and should not be construed to represent those of the US Department of the Army or the US Department of Defense

Co-circulation of West Nile virus and distinct insect-specific flaviviruses in Turkey

Background: Active vector surveillance provides an efficient tool for monitoring the presence or spread of emerging or re-emerging vector-borne viruses. This study was undertaken to investigate the circulation of flaviviruses. Mosquitoes were collected from 58 locations in 10 provinces across the Aegean, Thrace and Mediterranean Anatolian regions of Turkey in 2014 and 2015. Following morphological identification, mosquitoes were pooled and screened by nested and real-time PCR assays. Detected viruses were further characterised by sequencing. Positive pools were inoculated onto cell lines for virus isolation. Next generation sequencing was employed for genomic characterisation of the isolates. Results: A total of 12,711 mosquito specimens representing 15 species were screened in 594 pools. Eleven pools (2%) were reactive in the virus screening assays. Sequencing revealed West Nile virus (WNV) in one Culex pipiens (s.l.) pool from Thrace. WNV sequence corresponded to lineage one clade 1a but clustered distinctly from the Turkish prototype isolate. In 10 pools, insect-specific flaviviruses were characterised as Culex theileri flavivirus in 5 pools of Culex theileri and one pool of Cx. pipiens (s.l.), Ochlerotatus caspius flavivirus in two pools of Aedes (Ochlerotatus) caspius, Flavivirus AV-2011 in one pool of Culiseta annulata, and an undetermined flavivirus in one pool of Uranotaenia unguiculata from the Aegean and Thrace regions. DNA forms or integration of the detected insect-specific flaviviruses were not observed. A virus strain, tentatively named as “Ochlerotatus caspius flavivirus Turkey”, was isolated from an Ae. caspius pool in C6/36 cells. The viral genome comprised 10,370 nucleotides with a putative polyprotein of 3,385 amino acids that follows the canonical flavivirus polyprotein organisation. Sequence comparisons and phylogenetic analyses revealed the close relationship of this strain with Ochlerotatus caspius flavivirus from Portugal and Hanko virus from Finland. Several conserved structural and amino acid motifs were identified. Conclusions: We identified WNV and several distinct insect-specific flaviviruses during an extensive biosurveillance study of mosquitoes in various regions of Turkey in 2014 and 2015. Ongoing circulation of WNV is revealed, with an unprecedented genetic diversity. A probable replicating form of an insect flavivirus identified only in DNA form was detected

Effects of preoperative endoscopic pneumatic balloon dilatation on postoperative achalasia symptoms after Heller esophageal myotomy plus Dor fundoplication.

Conclusion: HM+DF is an effective procedure in relieving achalasia symptoms as a first-line therapy as well as in individuals unresponsive to repeated endoscopic PBDs