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Microorganisms Jun 2019Malaria is a severe disease caused by parasites of the genus , which is transmitted to humans by a bite of an infected female mosquito of the species . Malaria remains... (Review)
Review
Malaria is a severe disease caused by parasites of the genus , which is transmitted to humans by a bite of an infected female mosquito of the species . Malaria remains the leading cause of mortality around the world, and early diagnosis and fast-acting treatment prevent unwanted outcomes. It is the most common disease in Africa and some countries of Asia, while in the developed world malaria occurs as imported from endemic areas. The sweet sagewort plant was used as early as the second century BC to treat malaria fever in China. Much later, quinine started being used as an antimalaria drug. A global battle against malaria started in 1955, and Croatia declared 1964 to be the year of eradication of malaria. The World Health Organization carries out a malaria control program on a global scale, focusing on local strengthening of primary health care, early diagnosis of the disease, timely treatment, and disease prevention. Globally, the burden of malaria is lower than ten years ago. However, in the last few years, there has been an increase in the number of malaria cases around the world. It is moving towards targets established by the WHO, but that progress has slowed down.
PubMed: 31234443
DOI: 10.3390/microorganisms7060179 -
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 -
Frontiers in Microbiology 2022Malaria remains a vector-borne infectious disease that is still a major public health concern worldwide, especially in tropical regions. Malaria is caused by a protozoan... (Review)
Review
Malaria remains a vector-borne infectious disease that is still a major public health concern worldwide, especially in tropical regions. Malaria is caused by a protozoan parasite of the genus and transmitted through the bite of infected female mosquitoes. The control interventions targeting mosquito vectors have achieved significant success during the last two decades and rely mainly on the use of chemical insecticides through the insecticide-treated nets (ITNs) and indoor residual spraying (IRS). Unfortunately, resistance to conventional insecticides currently being used in public health is spreading in the natural mosquito populations, hampering the long-term success of the current vector control strategies. Thus, to achieve the goal of malaria elimination, it appears necessary to improve vector control approaches through the development of novel environment-friendly tools. Mosquito microbiota has by now given rise to the expansion of innovative control tools, such as the use of endosymbionts to target insect vectors, known as "symbiotic control." In this review, we will present the viral, fungal and bacterial diversity of mosquitoes, including the bacteriophages. This review discusses the likely interactions between the vector microbiota and its fitness and resistance to insecticides.
PubMed: 35668761
DOI: 10.3389/fmicb.2022.891573 -
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 -
Infection, Genetics and Evolution :... Jun 2022Anopheles is a genus belonging to the Culicidae family, which has great medical importance due to its role as a vector of Plasmodium, the causative agent of malaria.... (Review)
Review
Anopheles is a genus belonging to the Culicidae family, which has great medical importance due to its role as a vector of Plasmodium, the causative agent of malaria. Great focus has been given to the salivary gland proteins (SGPs) group from Anopheles' functional genomics. This class of proteins is essential to blood-feeding behavior as they have attributes such as vasodilators and anti-clotting properties. Recently, a comprehensive review on Anopheles SGPs was performed; however, the authors did not deeply explore the adaptive molecular evolution of these genes. In this context, this work aimed to perform a more detailed analysis of the adaptive molecular evolution of SGPs in Anopheles, carrying out positive selection and gene family evolution analysis on 824 SGPs. Our results show that most SGPs have positively selected codon sites that can be used as targets in developing new strategies for vector control and that younger SGPs evolve at a faster rate than older SGPs. Notably, we could not find any evidence of an accelerated shift in SGPs' rates of gene gain and loss compared with other proteins, as suggested in previous works.
Topics: Animals; Anopheles; Evolution, Molecular; Insect Proteins; Malaria; Mosquito Vectors; Salivary Proteins and Peptides
PubMed: 35339698
DOI: 10.1016/j.meegid.2022.105271 -
Revista Da Sociedade Brasileira de... 2022Malaria is a global health problem and is transmitted by the Anopheles species. Due to the epidemiological importance of the genus, studies on biological, phylogenetic,...
BACKGROUND
Malaria is a global health problem and is transmitted by the Anopheles species. Due to the epidemiological importance of the genus, studies on biological, phylogenetic, and evolutionary aspects have contributed to the understanding of adaptation, vector capacity, and resistance to insecticides. The latter may result from different causes such as mutations in the gene that encodes the sodium channel (NaV).
METHODS
In this study, the NaV subunit I scaffold of 17 anopheline species was used to infer phylogenetic relationships of the genus Anopheles using Bayesian inference. The evolutionary phylogenetic tree of the NaV gene was aligned in the AliView program and analyzed utilizing Bayesian inference, using the software MrBayes.
RESULTS
The anophelines were grouped into five well-supported clusters: 1 - Anopheles darlingi and Anopheles albimanus; 2 - Anopheles sinensis and Anopheles atroparvus; 3 - Anopheles dirus; 4 - Anopheles minimus, Anopheles culicifacies, Anopheles funestus, Anopheles maculatus, and Anopheles stephensi; and 5 - Anopheles christyi, Anopheles epiroticus, Anopheles merus, Anopheles melas, Anopheles gambiae, Anopheles coluzzii, and Anopheles arabiensis.
CONCLUSIONS
The topology confirms the phylogenetic relationships proposed in studies based on the genome of some anophelines and reflects the current taxonomy of the genus, which suggests that NaV undergoes selection pressure during the evolution of the species. These data are useful tools for inferring their ability to resist insecticides and also help in better understanding the evolutionary processes of the genus Anopheles.
Topics: Animals; Anopheles; Phylogeny; Insecticides; Bayes Theorem; Mosquito Vectors; Sodium Channels
PubMed: 36287479
DOI: 10.1590/0037-8682-0701-2021 -
Heliyon Dec 2023In the department of Córdoba, 21 widely distributed species have been described, of which , , , and are the most abundant species, and the last three play a vectorial...
In the department of Córdoba, 21 widely distributed species have been described, of which , , , and are the most abundant species, and the last three play a vectorial role in Malaria transmission in Colombia. A correct taxonomic identification of malaria insect vectors is of vital importance for the development of effective vector control strategies. However, the identification of individuals from the genus presents difficulties due to the loss of relevant morphological characters during the transport and preservation of the collected specimens. In addition to the interspecific variations, and the intraspecific similarities of the species belonging to the subgenus since itpresents species complexes and cryptic species that difficults identification based only in morphological characteristics. The objective of this study was to characterize the barcode fragment of the COI gene and its genetic diversity for the identification of . and . in areas of high malaria transmission from the department of Córdoba. 67 individuals belonging to the species cytotype and 22 were identified, and additionally, 9 haplotypes were obtained for and 14 for distributed in the study areas. The values obtained in the and estimators indicate a low or null genetic differentiation and a high gene flow between most of the studied populations because they share the most frequent haplotypes of these two species. The maximum likelihood trees for these species showed that the specimens from Córdoba belong to the same mitochondrial lineage as those previously reported from Antioquia, Choco, and Norte de Santander.
PubMed: 38076053
DOI: 10.1016/j.heliyon.2023.e23006 -
Parasites & Vectors Sep 2021Despite the medical importance of mosquitoes of the genus Anopheles in the transmission of malaria and other human diseases, its phylogenetic relationships are not...
BACKGROUND
Despite the medical importance of mosquitoes of the genus Anopheles in the transmission of malaria and other human diseases, its phylogenetic relationships are not settled, and the characteristics of mitochondrial genome (mitogenome) are not thoroughly understood.
METHODS
The present study sequenced and analyzed the complete mitogenomes of An. peditaeniatus and An. nitidus, investigated genome characteristics, and inferred the phylogenetic relationships of 76 Anopheles spp.
RESULTS
The complete mitogenomes of An. peditaeniatus and An. nitidus are 15,416 and 15,418 bp long, respectively, and both include 13 PCGs, 22 tRNAs, two tRNAs and one control region (CR). Mitogenomes of Anopheles spp. are similar to those of other insects in general characteristics; however, the trnR and trnA have been reversed to "trnR-trnA," as has been reported in other mosquito genera. Genome variations mainly occur in CR length (493-886 bp) with six repeat unit types identified for the first time that demonstrate an evolutionary signal. The subgenera Lophopodomyia, Stethomyia, Kerteszia, Nyssorhynchus, Anopheles and Cellia are inferred to be monophyletic, and the phylogenetic analyses support a new phylogenetic relationship among the six subgenera investigated, in that subgenus Lophopodomyia is the sister to all other five subgenera, and the remaining five subgenera are divided into two clades, one of which is a sister-taxon subgenera Stethomyia + Kerteszia, and the other consists of subgenus Nyssorhynchus as the sister to a sister-group subgenera Anopheles + Cellia. Four series (Neomyzomyia, Pyretophorus, Neocellia and Myzomyia) of the subgenus Cellia, and two series (Arribalzagia and Myzorhynchus) of the subgenus Anopheles were found to be monophyletic, whereas three sections (Myzorhynchella, Argyritarsis and Albimanus) and their subdivisions of the subgenus Nyssorhynchus were polyphyletic or paraphyletic.
CONCLUSIONS
The study comprehensively uncovered the characteristics of mitogenome and the phylogenetics based on mitogenomes in the genus Anopheles, and provided information for further study on the mitogenomes, phylogenetics and taxonomic revision of the genus.
Topics: Animals; Anopheles; Base Sequence; Evolution, Molecular; Genome, Mitochondrial; Phylogeny; Sequence Analysis, DNA; Species Specificity
PubMed: 34488869
DOI: 10.1186/s13071-021-04963-4 -
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 -
Frontiers in Microbiology 2021Exposure of mosquitoes to numerous eukaryotic and prokaryotic microbes in their associated microbiomes has probably helped drive the evolution of the innate immune...
Exposure of mosquitoes to numerous eukaryotic and prokaryotic microbes in their associated microbiomes has probably helped drive the evolution of the innate immune system. To our knowledge, a metagenomic catalog of the eukaryotic microbiome has not been reported from any insect. Here we employ a novel approach to preferentially deplete host 18S ribosomal RNA gene amplicons to reveal the composition of the eukaryotic microbial communities of larvae sampled in Kenya, Burkina Faso and Republic of Guinea (Conakry). We identified 453 eukaryotic operational taxonomic units (OTUs) associated with larvae in nature, but an average of 45% of the 18S rRNA sequences clustered into OTUs that lacked a taxonomic assignment in the Silva database. Thus, the microbiome contains a striking proportion of novel eukaryotic taxa. Using sequence similarity matching and phylogenetic placement, the fraction of unassigned sequences was reduced to an average of 4%, and many unclassified OTUs were assigned as relatives of known taxa. A novel taxon of the genus in the phylum Apicomplexa (which also includes ) is widespread in larvae from East and West Africa. Notably, is present at fluctuating abundance among larval breeding sites, consistent with the expected pattern of an epidemic pathogen. Species richness of the eukaryotic microbiome was not significantly different across sites from East to West Africa, while species richness of the prokaryotic microbiome was significantly lower in West Africa. Laboratory colonies of harbor 26 eukaryotic OTUs, of which 38% ( = 10) are shared with wild populations, while 16 OTUs are unique to the laboratory colonies. Genetically distinct colonies co-housed in the same facility maintain different prokaryotic microbiome profiles, suggesting a persistent host genetic influence on microbiome composition. These results provide a foundation to understand the role of the eukaryotic microbiome in vector immunity and pathogen transmission. We hypothesize that prevalent apicomplexans such as associated with could induce interference or competition against within the vector. This and other members of the eukaryotic microbiome may offer candidates for new vector control tools.
PubMed: 34054746
DOI: 10.3389/fmicb.2021.635772