Characterization of Dak Nong virus, an insect nidovirus isolated from Culex mosquitoes in Vietnam.
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ABSTRACT:
SUBMITTER: Kuwata R
PROVIDER: S-EPMC7087109 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:Microbiota of Anopheles midgut can modulate vector immunity and block Plasmodium development. Investigation on the bacterial biodiversity in Anopheles, and specifically on the identification of bacteria that might be used in malaria transmission blocking approaches, has been mainly conducted on malaria vectors of Africa. Vietnam is an endemic country for both malaria and Bancroftian filariasis whose parasitic agents can be transmitted by the same Anopheles species. No information on the microbiota of Anopheles mosquitoes in Vietnam was available previous to this study. METHOD:The culture dependent approach, using different mediums, and culture independent (16S rRNA PCR - TTGE) method were used to investigate the bacterial biodiversity in the abdomen of 5 Anopheles species collected from Dak Nong Province, central-south Vietnam. Molecular methods, sequencing and phylogenetic analysis were used to characterize the microbiota. RESULTS AND DISCUSSION:The microbiota in wild-caught Anopheles was diverse with the presence of 47 bacterial OTUs belonging to 30 genera, including bacterial genera impacting Plasmodium development. The bacteria were affiliated with 4 phyla, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, the latter being the dominant phylum. Four bacterial genera are newly described in Anopheles mosquitoes including Coxiella, Yersinia, Xanthomonas, and Knoellia. The bacterial diversity per specimen was low ranging from 1 to 4. The results show the importance of pairing culture and fingerprint methods to better screen the bacterial community in Anopheles mosquitoes. CONCLUSION:Sampled Anopheles species from central-south Vietnam contained a diverse bacterial microbiota that needs to be investigated further in order to develop new malaria control approaches. The combination of both culture and DNA fingerprint methods allowed a thorough and complementary screening of the bacterial community in Anopheles mosquitoes.
| S-EPMC4352016 | biostudies-literature
Project description:BACKGROUND: Human malaria is still a burden in Dak Nong and Binh Phuoc Provinces in south-central Vietnam that border Cambodia. Several Anopheles species that transmit human malarial Plasmodium may also transmit Wuchereria bancrofti, the nematode that causes Bancroftian lymphatic filariasis. The objective of this study was to investigate the role of Anopheles species in the transmission of these two pathogens in the two highly malaria endemic provinces of Vietnam. METHODS: Anopheles mosquitoes were collected in Dak Nong and Binh Phuoc Provinces in November and December of 2010 and 2011. Human landing catches, paired collections on human and buffalo, and resting captures were made with mouth aspirators. Collections were also made with light traps. Morphological and PCR-based methods were used to identify the species. Real-time PCR was used to detect Plasmodium species and W. bancrofti in individual mosquitoes. RESULTS: Twenty-four Anopheles species were identified among 797 captured mosquitoes. Anopheles dirus was found in both provinces and was the predominant species in Binh Phuoc Province; An. maculatus was the most prevalent species in Dak Nong Province. Anopheles minimus was collected only in Binh Phuoc Province. Some specimens of An. minimus and An. pampanai were misidentified based on morphology. Four specimens of An. scanloni were identified, and this is the first report of this species of the Dirus Complex in Vietnam. Two females, one An. dirus and one An. pampanai, collected in Binh Phuoc Province were infected with P. vivax, for an overall infection rate of 0.41% (2/486): 0.28% for An. dirus (1/361) and 20% for An. pampanai (1/5). No mosquitoes were found to be infected with P. falciparum, P. knowlesi or W. bancrofti in either province. CONCLUSION: A diversity of Anopheles species occurs in Dak Nong and Binh Phuoc Provinces of Vietnam, several of which are considered to be actual and potential vectors of malarial protozoa and microfilariae. It is highly likely that two of the species, An. dirus and An. pampanai, are active in malaria transmission based on the detection of P. vivax in females of these species. This is the first report of An. scanloni in Vietnam.
| S-EPMC4227083 | biostudies-literature
Project description:Traditional/herbal medicine has gained increasing interests recently, especially in Asian countries such as Vietnam, due to its diverse therapeutic actions. In the treasure of Vietnamese medicinal plants, one of the potential herbs is the roots of Sophora flavescens Ait. (SF, "Kho sam" in Vietnamese). However, limited information has been reported on the Vietnamese SF compositions and their respective alkaloids' anti-acetylcholinesterase action. Thus, this study investigated the extractions, isolations, identifications, and in-vitro antioxidant, cytotoxicity, and acetylcholinesterase inhibitory activities, of the SF root extracts and their purified alkaloid compounds. To this end, four pure compounds were successfully isolated, purity-tested by HPLC, and structurally identified by spectroscopic techniques of FTIR, MS, and NMR. These compounds, confirmed to be oxysophocarpine, oxymatrine, matrine, and sophoridine, were then determined their therapeutic actions. The SF extracts and the compounds did not possess significant antioxidant activity using the DPPH and MDA assays, and cytotoxicity action using the MTT assay on the MDA-MB-231 breast cancer cell line. On the other hand, the SF total extract yielded a moderate acetylcholinesterase inhibition effect, with an IC50 of 0.1077 ± 0.0023 mg/mL. In summary, the SF extract demonstrated potential effects as an anti-acetylcholinesterase agent and could be further researched to become a pharmaceutical product for diseases related to acetylcholine deficiency, such as dementia.
| S-EPMC9696406 | biostudies-literature
Project description:We describe the full genetic characterization of an insect-specific flavivirus (ISF) from Culex theileri (Theobald) mosquitoes collected in Portugal. This represents the first isolation and full characterization of an ISF from Portuguese mosquitoes. The virus, designated CTFV, for Culex theileri flavivirus, was isolated in the C6/36 Stegomyia albopicta (=Aedes albopictus) cell line, and failed to replicate in vertebrate (Vero) cells in common with other ISFs. The CTFV genome encodes a single polyprotein with 3357 residues showing all the features expected for those of flaviviruses. Phylogenetic analyses based on all ISF sequences available to date, place CTFV among Culex-associated flaviviruses, grouping with recently published NS5 partial sequences documented from mosquitoes collected in the Iberian Peninsula, and with Quang Binh virus (isolated in Vietnam) as a close relative. No CTFV sequences were found integrated in their host's genome using a range of specific PCR primers designed to the prM/E, NS3, and NS5 region.
| S-EPMC3919203 | biostudies-literature
Project description:Asymptomatic parasite carriers represent a "silent" infective reservoir for malaria transmission and contributes to malaria persistence. However, limited data are available on asymptomatic malaria in Vietnam. Between November 2018 and March 2019, we conducted a malaria epidemiological survey of asymptomatic people (children ≥ 10 years old and adults ≥18 years old, n = 2,809) residing in three communes in Tuy Duc district, Dak Nong province in the Central Highlands of Vietnam. Based on the national stratification of malaria risk, Dak Buk So, Dak Ngo and Quang Truc communes were classified by the National Malaria Control Programme as low, moderate and high malaria endemic areas, respectively. Using participants' finger prick blood samples, malaria parasites were detected by one-step reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The median age (Interquartile Range) for adults and children were 35 years (26-50) and 12 years (11-14), respectively. The prevalence of asymptomatic malaria was 1.7% (22/1,328), 3.5% (31/890) and 12.2% (72/591) for participants from Dak Buk So, Dak Ngo and Quang Truc, respectively. The prevalence of asymptomatic malaria was lower in children compared to adults: 2.6% (9/352) versus 4.7% (116/2,457) (Odds Ratio 0.53, 95% Confidence Interval 0.28 to1.02). Ownership of long-lasting insecticide-treated bed nets and hammocks was 97.1%, 99.0% and 94.7% for participants in Dak Buk So, Dak Ngo and Quang Truc, respectively, however, only 66.0%, 57.3% and 42.8% of the participants reported using bed nets every night. Of the several risk factors examined, going to the forest two weeks prior to enrolment into the study and sleeping in the forest had a significant association with participants being infected with asymptomatic malaria in Quang Truc, but not in the other two communes. Knowledge of the prevalence and distribution of asymptomatic malaria will help design and evaluate future intervention strategies for malaria elimination in Vietnam.
| S-EPMC8528296 | biostudies-literature
Project description:Pools of mosquitoes were tested for insect-specific viruses using cytopathic effect (CPE) assays on Aedes albopictus (C6/36) cells. Illumina sequencing of RNA from pool TR7094, which produced extensive CPE 2 days post-infection, yielded the complete genome sequences of a previously unknown Bunyavirus, designated Cumuto virus (CUMV), and a second virus designated Wallerfield virus (WALV). WALV shared highest amino acid identity (60.1 %) with Dezidougou virus from Côte d'Ivoire, a positive-sense, single-strand RNA, insect-specific virus belonging to the newly proposed genus Negevirus associated with mosquitoes and phlebotomine sandflies. The S, M and L segments of CUMV were most closely related to those of Gouleako virus, also from Côte d'Ivoire (amino acid identities of 36 %, 38% and 54 % respectively). Neither virus produced CPE on vertebrate cells, or illness in newborn mice. Isolation and characterization of these viruses increase our knowledge of the geographical distribution, diversity and host range of mosquito-specific bunyaviruses and negeviruses.
| S-EPMC3917067 | biostudies-literature
Project description:We isolated and characterized a Banna virus from mosquitoes in Vietnam; 5 strains were isolated from field-caught mosquitoes at various locations; Banna virus was previously isolated from encephalitis patients in Yunnan, China, in 1987. Together, these findings suggest widespread distribution of this virus throughout Southeast Asia.
| S-EPMC2600385 | biostudies-literature
Project description:The family Tymoviridae comprises positive-sense RNA viruses, which mainly infect plants. Recently, a few Tymoviridae-like viruses have been found in mosquitoes, which feed on vertebrate sources. We describe a novel Tymoviridae-like virus, putatively named, Guachaca virus (GUAV), isolated from Culex pipiens and Culex quinquefasciatus species of mosquitoes and collected in the rural area of Santa Marta, Colombia. After a cytopathic effect was observed in C6/36 cells, RNA was extracted and processed through the NetoVIR next-generation sequencing protocol, and data were analyzed through the VirMAP pipeline. Molecular and phenotypic characterization of the GUAV was achieved using a 5'/3' RACE, transmission electron microscopy, amplification in vertebrate cells, and phylogenetic analysis. A cytopathic effect was observed in C6/36 cells three days post-infection. The GUAV genome was successfully assembled, and its polyadenylated 3' end was corroborated. GUAV shared only 54.9% amino acid identity with its closest relative, Ek Balam virus, and was grouped with the latter and other unclassified insect-associated tymoviruses in a phylogenetic analysis. GUAV is a new member of a family previously described as comprising plant-infecting viruses, which seem to infect and replicate in mosquitoes. The sugar- and blood-feeding behavior of the Culex spp., implies a sustained contact with plants and vertebrates and justifies further studies to unravel the ecological scenario for transmission.
| S-EPMC10143313 | biostudies-literature
Project description:BACKGROUND:Mosquitoes are the potential vectors for a variety of viruses that can cause diseases in the human and animal populations. Viruses in the order Picornavirales infect a broad range of hosts, including mosquitoes. In this study, we aimed to characterize a novel picorna-like virus from the Culex spp. of mosquitoes from the Zambezi Valley of Mozambique. METHODS:The extracted RNA from mosquito pools was pre-amplified with the sequence independent single primer amplification (SISPA) method and subjected to high-throughput sequencing using the Ion Torrent platform. Reads that are classified as Iflaviridae, Picornaviridae and Dicistroviridae were assembled by CodonCode Aligner and SPAdes. Gaps between the viral contigs were sequenced by PCR. The genomic ends were analyzed by 5' and 3' RACE PCRs. The ORF was predicted with the NCBI ORF finder. The conserved domains were identified with ClustalW multiple sequence alignment, and a phylogenetic tree was built with MEGA. The presence of the virus in individual mosquito pools was detected by RT-PCR assay. RESULTS:A near full-length viral genome (9740 nt) was obtained in Culex mosquitoes that encoded a complete ORF (3112 aa), named Culex picorna-like virus (CuPV-1). The predicted ORF had 38% similarity to the Hubei picorna-like virus 35. The sequence of the conserved domains, Helicase-Protease-RNA-dependent RNA polymerase, were identified by multiple sequence alignment and found to be at the 3' end, similar to iflaviruses. Phylogenetic analysis of the putative RdRP amino acid sequences indicated that the virus clustered with members of the Iflaviridae family. CuPV-1 was detected in both Culex and Mansonia individual pools with low infection rates. CONCLUSIONS:The study reported a highly divergent, near full-length picorna-like virus genome from Culex spp. mosquitoes from Mozambique. The discovery and characterization of novel viruses in mosquitoes is an initial step, which will provide insights into mosquito-virus interaction mechanisms, genetic diversity and evolution.
| S-EPMC5907373 | biostudies-literature
Project description:A new Getah virus (GETV) strain, B254, was isolated from Culex fuscocephalus mosquitoes captured at Mount Ophir, Malaysia, in 2012. Phylogenetic analyses revealed that GETV B254 is distinct from the old Malaysia GETV MM2021 strain but closely related to group IV GETV from Russia (LEIV16275Mag), China (YN12031), and Thailand (GETV/SW/Thailand/2017).
| S-EPMC8798705 | biostudies-literature