Project description:Ilhéus virus (ILHV)(Flaviviridae:Orthoflavivirus) is an arthropod-borne virus (arbovirus) endemic to Central and South America and the Caribbean. First isolated in 1944, most of our knowledge derives from surveillance and seroprevalence studies. These efforts have detected ILHV in a broad range of mosquito and vertebrate species, including humans, but laboratory investigations of pathogenesis and vector competence have been lacking. Here, we develop an immune intact murine model with several ages and routes of administration. Our model closely recapitulates human neuroinvasive disease with ILHV strain- and mouse age-specific virulence, as well as a uniformly lethal Ifnar-/- A129 immunocompromised model. Replication kinetics in several vertebrate and invertebrate cell lines demonstrate that ILHV is capable of replicating to high titers in a wide variety of potential host and vector species. Lastly, vector competence studies provide strong evidence for efficient infection of and potential transmission by Aedes species mosquitoes, despite ILHV's phylogenetically clustering with Culex vectored flaviviruses, suggesting ILHV is poised for emergence in the neotropics.
Project description:White spot syndrome virus (WSSV) is the most devastating viral disease affecting cultivated shrimp around the world. Currently, there is no reported genetic information on WSSV affecting Penaeus vannamei in Ecuador. Therefore, we determined the genome of a WSSV isolate from shrimp and compared it with the genomes of isolates from other geographical locations.
Project description:The wetlands of the Brazilian Pantanal host large concentrations of diverse wildlife species and hematophagous arthropods, conditions that favor the circulation of zoonotic arboviruses. A recent study from the Nhecolândia sub-region of Pantanal reported serological evidence of various flaviviruses, including West Nile virus and Ilheus virus (ILHV). According to the age of seropositive horses, at least three flaviviruses, including ILHV, circulated in the Brazilian Pantanal between 2005 and 2009. To extend this study, we collected 3,234 adult mosquitoes of 16 species during 2009 and 2010 in the same sub-region. Mosquito pool homogenates were assayed for infectious virus on C6/36 and Vero cell monolayers and also tested for flaviviral RNA by a group-specific real-time RT-PCR. One pool containing 50 non-engorged female specimens of Aedes scapularis tested positive for ILHV by culture and for ILHV RNA by real-time RT-PCR, indicating a minimum infection rate of 2.5 per 1000. Full-length genomic sequence exhibited 95% identity to the only full genome sequence available for ILHV. The present data confirm the circulation of ILHV in the Brazilian Pantanal.
Project description:BackgroundThe Ilheus virus (ILHV) is an encephalitis associated arthropod-borne flavivirus. It was first identified in Ilheus City in the northeast Brazil before spreading to a wider geographic range. No specific vaccines or drugs are currently available for the treatment of ILHV infections. The ILHV helicase, like other flavivirus helicases, possesses 5'-triphosphatase activity. This allows it to perform ATP hydrolysis to generate energy as well as sustain double-stranded RNA's unwinding during ILHV genome replication. Thus, ILHV helicase is an ideal target for inhibitor design.ResultsWe determined the crystal structure of the ILHV helicase at 1.75-Å resolution. We then conducted molecular docking of ATP-Mn2+ to the ILHV helicase. Comparisons with related flavivirus helicases indicated that both the NTP and the RNA-ILHV helicase binding sites were conserved across intra-genus species. This suggested that ILHV helicase adopts an identical mode in recognizing ATP/Mn2+. However, the P-loop in the active site showed a distinctive conformation; reflecting a different local structural rearrangement. ILHV helicase enzymatic activity was also characterized. This was found to be relatively lower than that of the DENV, ZIKV, MVE, and ALSV helicases. Our structure-guided mutagenesis revealed that R26A, E110A, and Q280A greatly reduced the ATPase activities. Moreover, we docked two small molecule inhibitors of DENV helicase (ST-610 and suramin) to the ILHV helicase and found that these two molecules had the potential to inhibit the activity of ILHV helicase as well.ConclusionHigh-resolution ILHV helicase structural analysis demonstrates the key amino acids of ATPase activities and could be useful for the design of inhibitors targeting the helicase of ILHV.
Project description:Ilheus virus (ILHV) is a mosquito-borne flavivirus circulating throughout Central and South America and the Caribbean. It has been detected in several mosquito genera including Aedes and Culex, and birds are thought to be its primary amplifying and reservoir host. Here, we describe the genomic and morphologic characterization of ten ILHV strains. Our analyses revealed a high conservation of both the 5'- and 3'-untranslated regions but considerable divergence within the open reading frame. We also showed that ILHV displays a typical flavivirus structural and genomic organization. Our work lays the foundation for subsequent ILHV studies to better understand its transmission cycles, pathogenicity, and emergence potential.
Project description:We review epidemiological and clinical data on human myiasis from Ecuador, based on data from the Ministry of Public Health (MPH) and a review of the available literature for clinical cases. The larvae of four flies, Dermatobia hominis, Cochliomyia hominivorax, Sarcophaga haemorrhoidalis, and Lucilia eximia, were identified as the causative agents in 39 reported clinical cases. The obligate D. hominis, causing furuncular lesions, caused 17 (43.5%) cases distributed along the tropical Pacific coast and the Amazon regions. The facultative C. hominivorax was identified in 15 (38%) clinical cases, infesting wound and cavitary lesions including orbital, nasal, aural and vaginal, and occurred in both subtropical and Andean regions. C. hominivorax was also identified in a nosocomial hospital-acquired wound. Single infestations were reported for S. haemorrhoidalis and L. eximia. Of the 39 clinical cases, 8 (21%) occurred in tourists. Ivermectin, when it became available, was used to treat furuncular, wound, and cavitary lesions successfully. MPH data for 2013-2015 registered 2,187 cases of which 54% were reported in men; 46% occurred in the tropical Pacific coast, 30% in the temperate Andes, 24% in the tropical Amazon, and 0.2% in the Galapagos Islands. The highest annual incidence was reported in the Amazon (23 cases/100,000 population), followed by Coast (5.1/100,000) and Andes (4.7/100,000). Human myiasis is a neglected and understudied ectoparasitic infestation, being endemic in both temperate and tropical regions of Ecuador. Improved education and awareness among populations living in, visitors to, and health personnel working in high-risk regions, is required for improved epidemiological surveillance, prevention, and correct diagnosis and treatment.
Project description:Colistin resistance mediated by the mcr-1 gene has been reported worldwide, but to date not from the Andean region, South America. We report the first clinical isolate of Escherichia coli harbouring the mcr-1 gene in Ecuador. The strain was isolated from peritoneal fluid from a 14-year-old male with acute appendicitis, and subjected to molecular analysis. The minimum inhibitory concentration of colistin for the strain was 8 mg/ml and it was susceptible to carbapenems but resistant to tigecycline. The strain harboured mcr-1 and bla CTX-M-55 genes and was of sequence type 609. The recognition of an apparently commensal strain of E. coli harbouring mcr-1 serves as an alert to the presence in the region of this recently described resistance mechanism to one of the last line of drugs available for the treatment of multi-resistant Gram-negative infections.
Project description:Ilheus virus is an arbovirus with the potential for central nervous system involvement. Accurate diagnosis is a challenge due to similar clinical symptoms and serologic cross-reactivity with other flaviviruses. Here, we describe the first documented case of a fatal outcome following the identification of Ilheus virus in the cerebrospinal fluid (CSF) of a patient with cerebral encephalitis in Brazil.
Project description:We isolated Andes virus (formal name: Andes virus [ANDV], a species in the genus Hantavirus), from serum of an asymptomatic 10-year-old Chilean boy who died 6 days later of hantavirus pulmonary syndrome (HPS). The serum was obtained 12 days after his grandmother died from HPS and 2 days before he became febrile. No hantavirus immunoglobulin (Ig) G or IgM antibodies were detected in the serum sample. After three blind passages, ANDV antigens were detected in Vero E6 cells by immunofluorescence assay and enzyme-linked immunosorbent assay, and ANDV RNA was detected by reverse transcription-polymerase chain reaction. A fragment of the virus genome showed 96.2% nucleotide identity with that of prototype ANDV. To our knowledge, this is the first isolation of any agent of hemorrhagic fever with HPS from a human and the first such isolation of hantavirus before symptoms of that syndrome or HPS began.