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Frontiers in Genetics 2020The principles and function of chromatin and nuclear architecture have been extensively studied in model organisms, such as . However, little is known about the role of... (Review)
Review
The principles and function of chromatin and nuclear architecture have been extensively studied in model organisms, such as . However, little is known about the role of these epigenetic processes in transcriptional regulation in other insects including mosquitoes, which are major disease vectors and a worldwide threat for human health. Some of these life-threatening diseases are malaria, which is caused by protozoan parasites of the genus and transmitted by mosquitoes; dengue fever, which is caused by an arbovirus mainly transmitted by ; and West Nile fever, which is caused by an arbovirus transmitted by spp. In this contribution, we review what is known about chromatin-associated mechanisms and the 3D genome structure in various mosquito vectors, including , , and spp. We also discuss the similarities between epigenetic mechanisms in mosquitoes and the model organism , and advocate that the field could benefit from the cross-application of state-of-the-art functional genomic technologies that are well-developed in the fruit fly. Uncovering the mosquito regulatory genome can lead to the discovery of unique regulatory networks associated with the parasitic life-style of these insects. It is also critical to understand the molecular interactions between the vectors and the pathogens that they transmit, which could hold the key to major breakthroughs on the fight against mosquito-borne diseases. Finally, it is clear that epigenetic mechanisms controlling mosquito environmental plasticity and evolvability are also of utmost importance, particularly in the current context of globalization and climate change.
PubMed: 33365050
DOI: 10.3389/fgene.2020.602949 -
Current Infectious Disease Reports 2022West Nile virus (WNV) is an arbovirus transmitted by mosquitos of the genus . Manifestations of WNV infection range from asymptomatic to devastating neuroinvasive... (Review)
Review
PURPOSE OF REVIEW
West Nile virus (WNV) is an arbovirus transmitted by mosquitos of the genus . Manifestations of WNV infection range from asymptomatic to devastating neuroinvasive disease leading to flaccid paralysis and death. This review examines WNV epidemiology and ecology, with an emphasis on travel-associated infection.
RECENT FINDINGS
WNV is widespread, including North America and Europe, where its range has expanded in the past decade. Rising temperatures in temperate regions are predicted to lead to an increased abundance of mosquitoes and an increase in their ability to transmit WNV. Although the epidemiologic patterns of WNV appear variable, its geographic distribution most certainly will continue to increase. Travelers are at risk for WNV infection and its complications. Literature review identified 39 cases of documented travel-related WNV disease, the majority of which resulted in adverse outcomes, such as neuroinvasive disease, prolonged recovery period, or death.
SUMMARY
The prediction of WNV risk is challenging due to the complex interactions of vector, pathogen, host, and environment. Travelers planning to visit endemic areas should be advised regarding WNV risk and mosquito bite prevention. Evaluation of ill travelers with compatible symptoms should consider the diagnosis of WNV for those visiting in endemic areas as well as for those returning from destinations with known WNV circulation.
PubMed: 35965880
DOI: 10.1007/s11908-022-00783-4 -
Human Vaccines & Immunotherapeutics Jan 2018Japanese encephalitis (JE) is the most commonly diagnosed viral encephalitis in Asia. JE is caused by a virus called JE virus (JEV), a member of the genus Flavivirus,... (Review)
Review
Japanese encephalitis (JE) is the most commonly diagnosed viral encephalitis in Asia. JE is caused by a virus called JE virus (JEV), a member of the genus Flavivirus, family Flaviviridae, and is transmitted by Culex mosquitoes. Neutralising antibody to JEV protects against JE, and can be induced by vaccination. JE is a potential threat to travellers to endemic areas, which are most of South and Southeast Asia and some Pacific Islands. The risk of JE can be expected to increase with increasing mosquito exposure and time spent in regions and seasons of active transmission. JE is very rare in travellers, but mortality is high, around 1 in 3, and there is a high rate of lasting neurological damage. JE can therefore be a profoundly life changing event for a traveller. Travellers and their healthcare providers need to balance the low risk of disease against the very high severity of disease if it does occur. In order to make an informed decision, the severity of JE disease should be carefully explained to travellers to Asia.
Topics: Asia; Decision Making; Encephalitis Virus, Japanese; Encephalitis, Japanese; Endemic Diseases; Humans; Japanese Encephalitis Vaccines; Risk Assessment; Seasons; Severity of Illness Index; Travel-Related Illness; Vaccination
PubMed: 29244615
DOI: 10.1080/21645515.2017.1380756 -
Pathogens (Basel, Switzerland) Jan 2021Arthropod-borne viral diseases (arboviruses) are a public-health concern in many regions of the world, including Thailand. This review describes the potential vectors... (Review)
Review
Arthropod-borne viral diseases (arboviruses) are a public-health concern in many regions of the world, including Thailand. This review describes the potential vectors and important human and/or veterinary arboviruses in Thailand. The medically important arboviruses affect humans, while veterinary arboviruses affect livestock and the economy. The main vectors described are mosquitoes, but other arthropods have been reported. Important mosquito-borne arboviruses are transmitted mainly by members of the genus (e.g., dengue, chikungunya, and Zika virus) and (e.g., Japanese encephalitis, Tembusu and West Nile virus). While mosquitoes are important vectors, arboviruses are transmitted via other vectors, such as sand flies, ticks, cimicids (Family ) and . Veterinary arboviruses are reported in this review, e.g., duck Tembusu virus (DTMUV), Kaeng Khoi virus (KKV), and African horse sickness virus (AHSV). During arbovirus outbreaks, to target control interventions appropriately, it is critical to identify the vector(s) involved and their ecology. Knowledge of the prevalence of these viruses, and the potential for viral infections to co-circulate in mosquitoes, is also important for outbreak prediction.
PubMed: 33477699
DOI: 10.3390/pathogens10010080 -
Parasites & Vectors Aug 2018Mosquito-borne diseases cause major human diseases in almost every part of the world. In West Africa, and notably in Mali, vector control measures help reduce the impact... (Review)
Review
Mosquito-borne diseases cause major human diseases in almost every part of the world. In West Africa, and notably in Mali, vector control measures help reduce the impact of mosquito-borne diseases, although malaria remains a threat to both morbidity and mortality. The most recent overview article on mosquitoes in Mali was published in 1961, with a total of 88 species. Our present review focuses on mosquitoes of medical importance among which the Anopheles vectors of Plasmodium and filaria, as well as the Culex and Aedes vectors of arboviruses. It aims to provide a concise update of the literature on Culicidae, covering the ecological areas in which the species are found but also the transmitted pathogens and recent innovative tools for vector surveys. This review highlights the recent introduction of invasive mosquito species, including Aedes albopictus and Culex neavei. The comprehensive list of mosquito species currently recorded includes 106 species (28 species of the Anophelinae and 78 species of the Culicinae). There are probable gaps in our knowledge concerning mosquitoes of the subfamily Culicinae and northern half of Mali because most studies have been carried out on the genus Anopheles and have taken place in the southern part of the country. It is hoped that this review may be useful to decision makers responsible for vector control strategies and to researchers for future surveys on mosquitoes, particularly the vectors of emerging arboviruses.
Topics: Animals; Culicidae; Humans; Mali; Mosquito Vectors
PubMed: 30103823
DOI: 10.1186/s13071-018-3045-8 -
Insects Jan 2022Combining thermopreference (T) and CO-gated heat-seeking assays, we studied the thermal and response to thermal cues in three mosquito species exhibiting differences...
Combining thermopreference (T) and CO-gated heat-seeking assays, we studied the thermal and response to thermal cues in three mosquito species exhibiting differences in native habitat and host preference (e.g., biting cold and/or warm-blooded animals). Results show that these species differ in both T and heat-seeking behavior. In particular, we found that , which feed primarily on cold-blood hosts, did not respond to heat during heat-seeking assays, regardless of the CO concentration, but exhibited an intermediate T during resting. In contrast, , which feeds on warm blooded hosts, sought the coolest locations on a thermal gradient and responded only moderately to thermal stimuli when paired with CO at higher concentrations. The third species, , which has been shown to feed on a wide range of hosts, responded to heat when paired with high CO levels and exhibited a high T. This study provides the first insights into the role of heat and CO in the host seeking behavior of three disease vectors in the genus and highlights differences in preferred resting temperatures.
PubMed: 35055936
DOI: 10.3390/insects13010092 -
Scientific Reports Nov 2023Microorganisms present in mosquitoes and their interactions are key factors affecting insect development. Among them, Wolbachia is closely associated with the host and... (Review)
Review
Microorganisms present in mosquitoes and their interactions are key factors affecting insect development. Among them, Wolbachia is closely associated with the host and affects several fitness parameters. In this study, the bacterial and fungal microbiota from two laboratory Culex quinquefasciatus isolines (wild type and tetracycline-cured) were characterized by metagenome amplicon sequencing of the ITS2 and 16S rRNA genes at different developmental stages and feeding conditions. We identified 572 bacterial and 61 fungal OTUs. Both isolines presented variable bacterial communities and different trends in the distribution of diversity among the groups. The lowest bacterial richness was detected in sugar-fed adults of the cured isoline, whereas fungal richness was highly reduced in blood-fed mosquitoes. Beta diversity analysis indicated that isolines are an important factor in the differentiation of mosquito bacterial communities. Considering composition, Penicillium was the dominant fungal genus, whereas Wolbachia dominance was inversely related to that of Enterobacteria (mainly Thorsellia and Serratia). This study provides a more complete overview of the mosquito microbiome, emphasizing specific highly abundant components that should be considered in microorganism manipulation approaches to control vector-borne diseases.
Topics: Animals; Aedes; Bacteria; Culex; Microbiota; Mosquito Vectors; RNA, Ribosomal, 16S; Wolbachia
PubMed: 37923779
DOI: 10.1038/s41598-023-46067-2 -
Pathogens (Basel, Switzerland) Aug 2022Getah virus (GETV) is a zoonotic virus transmitted by mosquitoes, belonging to the family, genus. It was first isolated from mosquitoes in Malaysia in 1955, being... (Review)
Review
Getah virus (GETV) is a zoonotic virus transmitted by mosquitoes, belonging to the family, genus. It was first isolated from mosquitoes in Malaysia in 1955, being widespread in island countries in the South Pacific region. Since the beginning of the 21st century, GETV expanded its range and geographical distribution from low-latitude tropical regions to 60° north latitude, being isolated from 17 different species of mosquitoes belonging to five genera of Culicidae (, , , and ), as well as from midges in Eurasia. Molecular genetic evolution analysis revealed large molecular differences between the mosquitoes currently circulating Eurasia and those in the South Pacific in 1950s. The number of disease outbreaks caused by GETV in animals is increasing alongside the types of animals infected, from horses and pigs to cattle, blue foxes and red pandas. The disease burden is severely underestimated, and the economic cost to livestock production remains unknown. Herein, we review GETV temporal and spatial distribution, molecular genetic evolution, transmission and data on disease outbreaks. This work provides a reference for public health workers engaged in GETV research and zoonotic disease prevention and control.
PubMed: 36015065
DOI: 10.3390/pathogens11080945 -
Parasites & Vectors Jan 2022Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a tool that has revolutionised clinical microbiology and has recently been...
BACKGROUND
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a tool that has revolutionised clinical microbiology and has recently been described as an innovative and effective approach to arthropod identification.
METHODS
In this study, mosquitoes were captured in Vietnam using four different methods (human landing catch, CDC light traps, BG-Sentinel traps, animal-baited net traps). A total of 4215 mosquitoes were captured and morphologically identified as belonging to three genera: Aedes, Anopheles and Culex. We randomly selected 1253 mosquitoes, including 662 specimens of 14 Anopheles species, 200 specimens of two Aedes species and 391 morphologically unidentified Culex specimens, for molecular and MALDI-TOF MS analysis. The DNA from 98 mosquitoes (69 Anopheles specimens, 23 Culex specimens and six Aedes sp. specimens) was subjected to molecular analysis, either to confirm our morphological identification or the MALDI-TOF MS results, as well as to identify the Culex species that were morphologically identified at the genus level and to resolve the discrepancies between the morphological identification and the MALDI-TOF MS identification.
RESULTS
High-quality MS spectra were obtained for 1058 of the 1253 specimens (84%), including 192/200 for Aedes, 589/662 for Anopheles and 277/391 for Culex. The blind test showed that 986/997 (99%) of the specimens were correctly identified by MALDI-TOF MS, with log score values ranging from 1.708 to 2.843. Eleven specimens of Culex could not be identified based on morphological features, MALDI-TOF MS or molecular analysis.
CONCLUSIONS
This study enabled us to identify several species of mosquitoes from Vietnam using MALDI-TOF MS, and to enrich our database of MALDI-TOF MS reference spectra.
Topics: Animals; Culicidae; DNA; Species Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 35090542
DOI: 10.1186/s13071-022-05149-2 -
PLoS Neglected Tropical Diseases Nov 2017Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) that recently caused outbreaks in the Americas. Over the past 60 years, this virus has been observed... (Review)
Review
Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) that recently caused outbreaks in the Americas. Over the past 60 years, this virus has been observed circulating among African, Asian, and Pacific Island populations, but little attention has been paid by the scientific community until the discovery that large-scale urban ZIKV outbreaks were associated with neurological complications such as microcephaly and several other neurological malformations in fetuses and newborns. This paper is a systematic review intended to list all mosquito species studied for ZIKV infection or for their vector competence. We discuss whether studies on ZIKV vectors have brought enough evidence to formally exclude other mosquitoes than Aedes species (and particularly Aedes aegypti) to be ZIKV vectors. From 1952 to August 15, 2017, ZIKV has been studied in 53 mosquito species, including 6 Anopheles, 26 Aedes, 11 Culex, 2 Lutzia, 3 Coquillettidia, 2 Mansonia, 2 Eretmapodites, and 1 Uranotaenia. Among those, ZIKV was isolated from 16 different Aedes species. The only species other than Aedes genus for which ZIKV was isolated were Anopheles coustani, Anopheles gambiae, Culex perfuscus, and Mansonia uniformis. Vector competence assays were performed on 22 different mosquito species, including 13 Aedes, 7 Culex, and 2 Anopheles species with, as a result, the discovery that A. aegypti and Aedes albopictus were competent for ZIKV, as well as some other Aedes species, and that there was a controversy surrounding Culex quinquefasciatus competence. Although Culex, Anopheles, and most of Aedes species were generally observed to be refractory to ZIKV infection, other potential vectors transmitting ZIKV should be explored.
Topics: Aedes; Americas; Animals; Anopheles; Culex; Disease Outbreaks; Humans; Microcephaly; Mosquito Vectors; Saliva; Zika Virus; Zika Virus Infection
PubMed: 29145400
DOI: 10.1371/journal.pntd.0005933