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Acta Tropica Jul 2024This research offers a comprehensive exploration of the microbial communities associated with vector mosquitoes from South Korea. Aedes albopictus, Anopheles sinensis,...
This research offers a comprehensive exploration of the microbial communities associated with vector mosquitoes from South Korea. Aedes albopictus, Anopheles sinensis, and Culex molestus are vectors of pathogens, and understanding the intricacies of their microbiome profile is paramount for unraveling their roles in disease transmission dynamics. In this study, we characterized the microbiome of the midguts of adult female vector mosquitoes collected from different locations in South Korea. After DNA extraction from dissected mosquito midguts, we used the Illumina MiSeq next-generation sequencing to obtain sequences spanning the V4 hypervariable region of the bacteria 16S rRNA. Morphological and molecular characterization using 506-bp mitochondrial 16S rRNA was used to identify the mosquito species before amplicon sequencing. Across the three vector mosquitoes surveyed, 21 bacteria genera belonging to 20 families and 5 phyla were discovered. Proteobacteria and Bacteriodota were the major phyla of bacteria associated with the three mosquito species. There were significant differences in the gut microbiome genera composition between the species and little variation in the gut microbiome between individuals of the same mosquito species. Wolbachia is the most dominant genus in Aedes while Aeromonas, Acinetobacter, and unassigned taxa are the most common in An. sinensis. In addition to that, Chromobacterium, Chryseobacterium, and Aeromonas are dominant in Cx. molestus. This study sheds light on the complex interactions between mosquitoes and their microbiome, revealing potential implications for vector competence, disease transmission, and vector control strategies.
Topics: Animals; Republic of Korea; RNA, Ribosomal, 16S; Aedes; Mosquito Vectors; Bacteria; Female; Culex; Anopheles; Gastrointestinal Microbiome; Microbiota; DNA, Bacterial; Phylogeny; Sequence Analysis, DNA; Wolbachia; High-Throughput Nucleotide Sequencing
PubMed: 38608996
DOI: 10.1016/j.actatropica.2024.107213 -
PloS One 2022Over the past 10 years, studies using high-throughput 16S rRNA gene sequencing have shown that mosquitoes harbor diverse bacterial communities in their digestive system....
Over the past 10 years, studies using high-throughput 16S rRNA gene sequencing have shown that mosquitoes harbor diverse bacterial communities in their digestive system. However, no previous research has examined the total bacteria community inside versus outside of mosquitoes and whether bacteria found on the outside could represent a potential health threat through mechanical transfer. We examined the bacterial community of the external surface and internal body of female Anopheles coluzzii adults collected from homes in Côte d'Ivoire, Africa, by Illumina sequencing of the V3 to V4 region of 16S rRNA gene. Anopheles coluzzii is in the Anopheles gambiae sensu lato (s.l.) species complex and important in the transmission of malaria. The total 16S rRNA reads were assigned to 34 phyla, 73 orders, 325 families, and 700 genera. At the genus level, the most abundant genera inside and outside combined were Bacillus, Staphylococcus, Enterobacter, Corynebacterium, Kocuria, Providencia, and Sphingomonas. Mosquitoes had a greater diversity of bacterial taxa internally compared to the outside. The internal bacterial communities were similar between homes, while the external body samples were significantly different between homes. The bacteria on the external body were associated with plants, human and animal skin, and human and animal infections. Internally, Rickettsia bellii and Rickettsia typhi were found, potentially of importance, since this genus is associated with human diseases. Based on these findings, further research is warranted to assess the potential mechanical transmission of bacteria by mosquitoes moving into homes and the importance of the internal mosquito microbiota in human health.
Topics: Animals; Humans; Anopheles; RNA, Ribosomal, 16S; Cote d'Ivoire; Malaria; Bacteria; Microbiota; Mosquito Vectors
PubMed: 36520830
DOI: 10.1371/journal.pone.0278912 -
Journal of Invertebrate Pathology Oct 2022Parathelohania is a genus of microsporidia that preferentially attacks Anopheline mosquitoes. This study explored some selective aspects of the epizootiology of...
Parathelohania is a genus of microsporidia that preferentially attacks Anopheline mosquitoes. This study explored some selective aspects of the epizootiology of Parathelohania iranica (Microsporidia: Amblyosporidae) in its malaria mosquito host Anopheles superpictus s.l. (Diptera: Culicidae). For this study, Sar-rok Village, a place adjacent to the type locality of the parasite, located at the central western part of Iran was visited twice a month to collect host larvae from mid-summer to mid-autumn of 2017-2021. Patent infections were detected by the whitish discoloration of the involved segments. Superficially uninfected larvae were reared up to 26 days in the insectary to elucidate hidden infections. Molecular investigation and laboratory trials were conducted to evaluate the possibility of secondary infections in subsequent days. Morphological characters were used to determine the sex of larvae and adults. Data were entered in SPSS 23.0 and analyzed with relevant statistical tests as needed. In total, 584 P. iranica infected larvae of An. superpictus s.l. were collected in the study years at day zero (D0). Extended observations in the insectary revealed that 849 larvae (84.2 %), 22 dead pupae (2.2 %), and 137 emerged adults (13.6 %) were also infected. In the first two years of the study, the mean infection rate for D0 and D0 + D1-D26 infections was 6.25 % and 15.6 %, respectively. Exposure experiments indicated that subsequent infections in larvae (D1-D26) were not affected by a possible source in the accompanying field water. Patent (D0) infections were seasonal and had about a month delay compared to the general population of larvae. Concealed infections of larvae (D1-D26) were significantly more frequent in late mosquito season (P < 0.01). It is proposed that the gradual decrease of ambient temperature and the shortening of day length postpones the growth and development of P. iranica in the affected larvae. Both sexes of larvae were involved and none of them survived beyond a couple of days. The frequency of infections in adult males (5.8 %) were significantly more than females (4 %) (P = 0.02). The infections of larvae were more common in the late mosquito season, and the infections of adults were more frequent in the early mosquito season. This suggests the relative importance of vertical and horizontal routes of transmission in early and late mosquito seasons, respectively. However, age-specific data revealed that only 26 % of hidden infections of larvae (D1-D26) were stemmed from I to II age group. This implies that the vertical route may be less efficient than the horizontal route in the transmission of P. iranica to the mosquito host. These inferences should be verified with further field and laboratory investigations.
Topics: Animals; Anopheles; Female; Larva; Male; Microsporidia; Water
PubMed: 36055409
DOI: 10.1016/j.jip.2022.107823 -
Journal of Arthropod-borne Diseases Mar 2021Among the blood-sucking insects, mosquitoes have a very special position, because they transmit parasites of the genus , which cause malaria as one of the main... (Review)
Review
BACKGROUND
Among the blood-sucking insects, mosquitoes have a very special position, because they transmit parasites of the genus , which cause malaria as one of the main vector-borne disease worldwide. The aim of this review study was to evaluate utility of complete mitochondrial genomes in phylogenetic classification of the species of .
METHODS
The complete mitochondrial genome sequences belonging to 28 species of the genus (n=32) were downloaded from NCBI. The phylogenetic trees were constructed using the ML, NJ, ME, and Bayesian inference methods.
RESULTS
In general, the results of the present survey revealed that the complete mitochondrial genomes act very accurately in recognition of the taxonomic and phylogenetic status of these species and provide a higher level of support than those based on individual or partial mitochondrial genes so that by using them, we can meticulously reconstruct and modify classification.
CONCLUSION
Understanding the taxonomic position of , can be a very effective step in better planning for controlling these malaria vectors in the world and will improve our knowledge of their evolutionary biology.
PubMed: 34277853
DOI: 10.18502/jad.v15i1.6483 -
PloS One 2019Whole mitogenome sequences (mtDNA) have been exploited for insect ecology studies, using them as molecular markers to reconstruct phylogenies, or to infer...
Whole mitogenome sequences (mtDNA) have been exploited for insect ecology studies, using them as molecular markers to reconstruct phylogenies, or to infer phylogeographic relationships and gene flow. Recent Anopheles phylogenomic studies have provided information regarding the time of deep lineage divergences within the genus. Here we report the complete 15,393 bp mtDNA sequences of Anopheles aquasalis, a Neotropical human malaria vector. When comparing its structure and base composition with other relevant and available anopheline mitogenomes, high similarity and conserved genomic features were observed. Furthermore, 22 mtDNA sequences comprising anopheline and Dipteran sibling species were analyzed to reconstruct phylogenies and estimate dates of divergence between taxa. Phylogenetic analysis using complete mtDNA sequences suggests that A. aquasalis diverged from the Anopheles albitarsis complex ~28 million years ago (MYA), and ~38 MYA from Anopheles darlingi. Bayesian analysis suggests that the most recent ancestor of Nyssorhynchus and Anopheles + Cellia was extant ~83 MYA, corroborating current estimates of ~79-100 MYA. Additional sampling and publication of African, Asian, and North American anopheline mitogenomes would improve the resolution of the Anopheles phylogeny and clarify early continental dispersal routes.
Topics: Animals; Anopheles; Base Composition; Computational Biology; Evolution, Molecular; Genome, Mitochondrial; Genomics; Humans; Molecular Sequence Annotation; Mosquito Vectors; Phylogeny; Phylogeography; Sequence Analysis, DNA; Whole Genome Sequencing
PubMed: 31479460
DOI: 10.1371/journal.pone.0219523 -
Parasites & Vectors May 2020The transmission of malaria is known to be sensitive to the survival (longevity, mortality) of its mosquito vector, yet there have been few reviews of estimates of this... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The transmission of malaria is known to be sensitive to the survival (longevity, mortality) of its mosquito vector, yet there have been few reviews of estimates of this important population parameter in the malaria-carrying genus Anopheles.
METHODS
We carried out a systematic search for and meta-analysis of survival estimates, framed around the methods of estimation, under the major groupings of ‛vertical' (based on stable age or stage frequencies), ‛horizontal' (based on recaptures of marked and released cohorts), and ‛parasitological' (proportion of infectious mosquitoes). Because of the intricacies of the estimation process we provide an outline of these methods.
RESULTS
By meta-analysis we quantify the average of the distribution of daily survival [Formula: see text] for vertical (0.83, 95% CI: 0.80-0.86), horizontal (0.73, 95% CI: 0.66-0.79) and parasitological (0.92, 95% CI: 0.86-0.95) methods.
CONCLUSIONS
The meta-analysis demonstrates the anticipated result that horizontal estimates are lowest because they estimate apparent survival (survival and non-emigration) rather than true survival. On the other hand, vertical methods make strong assumptions about the stability or stationarity of the underlying populations. Further potential sources of methodological bias are mentioned. The substantial differences in estimates between methods indicates that methodological biases need to be considered when making use of available survival estimates.
Topics: Animals; Anopheles; Humans; Longevity; Malaria; Models, Biological; Mosquito Control; Mosquito Vectors; Population Dynamics; Survival Analysis
PubMed: 32381111
DOI: 10.1186/s13071-020-04092-4 -
Vector Borne and Zoonotic Diseases... Apr 2024West Nile virus (WNV), Everglades virus (EVEV), and five species of were isolated from mosquitoes collected in the Everglades in 2016-2017. Prior studies of blood...
West Nile virus (WNV), Everglades virus (EVEV), and five species of were isolated from mosquitoes collected in the Everglades in 2016-2017. Prior studies of blood meals of mosquitoes in southern Florida have related findings to acquisition and transmission of EVEV, St. Louis encephalitis virus, and WNV, but not the viruses associated with the subgenus of the genus . In the present study, blood-fed mosquitoes were collected in the Everglades in 2016, 2017, 2021, and 2022, and from an industrial site in Naples, FL in 2017. Blood meals were identified to host species by PCR assays using mitochondrial gene. Blood meals were identified from complex and 11 mosquito species captured in the Florida Everglades and from 3 species collected from an industrial site. The largest numbers of blood-fed specimens were from , , , and . fed on mammals, birds, and reptiles, particularly American alligator. This mosquito species could transmit WNV to American alligator in the wild. acquired blood meals primarily from birds and mammals and frequently fed on medium-sized mammals and white-tailed deer. Water and wading birds were the primary avian hosts for and in the Everglades. Wading birds are susceptible to WNV and could serve as reservoir hosts. fed on five species of rodents, particularly black and hispid cotton rats. EVEV and three different species of have been isolated from the hispid cotton rat and in the Everglades. is likely acquiring and transmitting these viruses among hispid cotton rats and other rodents. The marsh rabbit was a frequent host for complex. complex, and other species could acquire Tensaw virus from rabbits. Our study contributes to a better understanding of the host and viral associations of mosquito species in southwestern Florida.
PubMed: 38648543
DOI: 10.1089/vbz.2023.0072 -
International Journal of Environmental... Jun 2021Malaria parasites are transmitted to humans by infectious female mosquitoes. Chemical-insecticide-based mosquito control has been successful in reducing the burden of...
Malaria parasites are transmitted to humans by infectious female mosquitoes. Chemical-insecticide-based mosquito control has been successful in reducing the burden of malaria. However, the emergence of insecticide resistance in malaria vectors and concerns about the effect of the chemicals on the environment, human health, and non-target organisms present a need for new or alternative vector control intervention tools. Biocontrol methods using aquatic invertebrate predators have emerged as a potential alternative and additional tool to control mosquito populations. Ecological control specifically makes use of species insights for improving the physical habitat conditions of competitors and predators of vectors. A first step towards this is to gain knowledge on the predation potential of several typically present macroinvertebrates. Hence, this study aimed at (1) examining the influence of the predation of hemipterans on the number of emerging adult mosquitoes and (2) detecting mosquito DNA in the gut of those predators. The prey and predators were collected from a range of water bodies located in the Gilgel Gibe watershed, southwest Ethiopia. A semi-field study was carried out using mesocosms which were constructed using plastic containers mimicking the natural aquatic habitat of immature mosquitoes. Adult mosquitoes that emerged from the mesocosms were collected using a mechanical aspirator. At the end of the experiment, predators were withdrawn from the mesocosms and identified to genus level. Polymerase Chain Reaction (PCR) was employed to identify sibling species of s.l. and to detect mosquito DNA in the gut of the predators. Data were analysed using R software. Giant water bugs (belostomatids) were the most aggressive predators of larvae, followed by backswimmers (notonectids) and water boatmen (corixids). All female s.l. emerged from the mesocosms were identified as . DNA was detected in the gut content of hemipteran specimens analysed from the three families. The number of the adult mosquitoes emerging from the mesocosms was affected by the presence of predators. The findings of this study provide evidence of the potential use of aquatic macroinvertebrate predators as biocontrol agents against immature mosquitoes and their potential to be considered as a component of integrated vector management for insecticide resistance and the combined restoration of aquatic ecosystems via smart ecological engineering.
Topics: Animals; Anopheles; Ecosystem; Ethiopia; Female; Humans; Insecticides; Larva; Malaria; Mosquito Control; Mosquito Vectors; Predatory Behavior
PubMed: 34199088
DOI: 10.3390/ijerph18136904 -
Heliyon Aug 2020Culicidae mosquitoes are main vectors of arboviruses that cause arboviral diseases in humans. Studies on fauna, ecology, biology, resting behaviors of Culicidae...
Culicidae mosquitoes are main vectors of arboviruses that cause arboviral diseases in humans. Studies on fauna, ecology, biology, resting behaviors of Culicidae mosquitoes are important and greatly impacts the control of arboviral diseases that are transmitted by vectors. The aim of the present study was to determine fauna of mosquitoes (Diptera: Culicidae) based on morphological and molecular (genomic) identification and their habitats in Lorestan province, Western Iran. Meanwhile mosquito samples were examined for arbovirus infection. Culicidae mosquitoes were caught in 2015 and 2016 from human homes, animal dwellings, storehouses and pit shelters in Lorestan province, Western Iran, using an oral aspirator (hand catch), total catch, human and animal bait and light trap methods. The samples were identified on the genus and species. Six species of Culex and eight species of Anopheles were caught. One complex species ( complex) and a hybrid between biotype and biotype were identified. Among all of the trapped mosquitoes (4211), 94.68% were from genus Culex mosquitoes (3987), which indicate that this genus is the dominant in Lorestan province, Western Iran. Anopheles comprised of 201 individuals out of the total catch. Arboviruses were not detected in these samples.
PubMed: 32775741
DOI: 10.1016/j.heliyon.2020.e04480 -
Morbidity and Mortality Weekly Report.... Sep 2022Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles species...
PROBLEM/CONDITION
Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles species mosquito. Most malaria infections in the United States and its territories occur among persons who have traveled to regions with ongoing malaria transmission. However, among persons who have not traveled out of the country, malaria is occasionally acquired through exposure to infected blood or tissues, congenital transmission, nosocomial exposure, or local mosquitoborne transmission. Malaria surveillance in the United States and its territories provides information on its occurrence (e.g., temporal, geographic, and demographic), guides prevention and treatment recommendations for travelers and patients, and facilitates rapid transmission control measures if locally acquired cases are identified.
PERIOD COVERED
This report summarizes confirmed malaria cases in persons with onset of illness in 2018 and trends in previous years.
DESCRIPTION OF SYSTEM
Malaria cases diagnosed by blood smear microscopy, polymerase chain reaction, or rapid diagnostic tests are reported to local and state health departments through electronic laboratory reports or by health care providers or laboratory staff members directly reporting to CDC or health departments. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), the National Notifiable Diseases Surveillance System (NNDSS), or direct CDC clinical consultations. CDC reference laboratories provide diagnostic assistance and conduct antimalarial drug resistance marker testing on blood specimens submitted by health care providers or local or state health departments. This report summarizes data from the integration of all cases from NMSS and NNDSS, CDC clinical consultations, and CDC reference laboratory reports.
RESULTS
CDC received reports of 1,823 confirmed malaria cases with onset of symptoms in 2018, including one cryptic case and one case acquired through a bone marrow transplant. The number of cases reported in 2018 is 15.6% fewer than in 2017. The number of cases diagnosed in the United States and its territories has been increasing since the mid-1970s; the number of cases reported in 2017 was the highest since 1972. Of the cases in 2018, a total of 1,519 (85.0%) were imported cases that originated from Africa; 1,061 (69.9%) of the cases from Africa were from West Africa, a similar proportion to what was observed in 2017. Among all cases, P. falciparum accounted for most infections (1,273 [69.8%]), followed by P. vivax (173 [9.5%]), P. ovale (95 [5.2%]), and P. malariae (48 [2.6%]). For the first time since 2008, an imported case of P. knowlesi was identified in the United States and its territories. Infections by two or more species accounted for 17 cases (<1.0%). The infecting species was not reported or was undetermined in 216 cases (11.9%). Most patients (92.6%) had symptom onset <90 days after returning to the United States or its territories from a country with malaria transmission. Of the U.S. civilian patients who reported reason for travel, 77.0% were visiting friends and relatives. Chemoprophylaxis with antimalarial medications are recommended for U.S. residents to prevent malaria while traveling in countries where it is endemic. Fewer U.S. residents with imported malaria reported taking any malaria chemoprophylaxis in 2018 (24.5%) than in 2017 (28.4%), and adherence was poor among those who took chemoprophylaxis. Among the 864 U.S. residents with malaria for whom information on chemoprophylaxis use and travel region were known, 95.0% did not adhere to or did not take a CDC-recommended chemoprophylaxis regimen. Among 683 women with malaria, 19 reported being pregnant. Of these, 11 pregnant women were U.S. residents, and one of whom reported taking chemoprophylaxis to prevent malaria but her adherence to chemoprophylaxis was not reported. Thirty-eight (2.1%) malaria cases occurred among U.S. military personnel in 2018, more than in 2017 (26 [1.2%]). Among all reported malaria cases in 2018, a total of 251 (13.8%) were classified as severe malaria illness, and seven persons died from malaria. In 2018, CDC analyzed 106 P. falciparum-positive and four P. falciparum mixed species specimens for antimalarial resistance markers (although certain loci were untestable in some specimens); identification of genetic polymorphisms associated with resistance to pyrimethamine were found in 99 (98.0%), to sulfadoxine in 49 (49.6%), to chloroquine in 50 (45.5%), and to mefloquine in two (2.0%); no specimens tested contained a marker for atovaquone or artemisinin resistance.
INTERPRETATION
The importation of malaria reflects the overall trends in global travel to and from areas where malaria is endemic, and 15.6% fewer cases were imported in 2018 compared with 2017. Of imported cases, 59.3% were among persons who had traveled from West Africa. Among U.S. civilians, visiting friends and relatives was the most common reason for travel (77.1%).
PUBLIC HEALTH ACTIONS
The best way for U.S. residents to prevent malaria is to take chemoprophylaxis medication before, during, and after travel to a country where malaria is endemic. Adherence to recommended malaria prevention strategies among U.S. travelers would reduce the number of imported cases. Reported reasons for nonadherence include prematurely stopping after leaving the area where malaria was endemic, forgetting to take the medication, and experiencing a side effect. Health care providers can make travelers aware of the risks posed by malaria and incorporate education to motivate them to be adherent to chemoprophylaxis. Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient's age, pregnancy status, medical history, the likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Antimalarial use for chemoprophylaxis and treatment should be determined by the CDC guidelines, which are frequently updated. In April 2019, intravenous (IV) artesunate became the first-line medication for treatment of severe malaria in the United States and its territories. Artesunate was approved by the Food and Drug Administration (FDA) in 2020 and is commercially available (Artesunate for Injection) from major U.S. drug distributors (https://amivas.com). Stocking IV artesunate locally allows for immediate treatment of severe malaria once diagnosed and provides patients with the best chance of a complete recovery and no sequelae. With commercial IV artesunate now available, CDC will discontinue distribution of non-FDA-approved IV artesunate under an investigational new drug protocol on September 30, 2022. Detailed recommendations for preventing malaria are online at https://www.cdc.gov/malaria/travelers/drugs.html. Malaria diagnosis and treatment recommendations are also available online at https://www.cdc.gov/malaria/diagnosis_treatment. Health care providers who have sought urgent infectious disease consultation and require additional assistance on diagnosis and treatment of malaria can call the Malaria Hotline 9:00 a.m.-5:00 p.m. Eastern Time, Monday-Friday, at 770-488-7788 or 855-856-4713 or after hours for urgent inquiries at 770-488-7100. Persons submitting malaria case reports (care providers, laboratories, and state and local public health officials) should provide complete information because incomplete reporting compromises case investigations and public health efforts to prevent future infections and examine trends in malaria cases. Molecular surveillance of antimalarial drug resistance markers enables CDC to track, guide treatment, and manage drug resistance in malaria parasites both domestically and globally. A greater proportion of specimens from domestic malaria cases are needed to improve the completeness of antimalarial drug resistance analysis; therefore, CDC requests that blood specimens be submitted for any case of malaria diagnosed in the United States and its territories.
Topics: Antimalarials; Artesunate; Biomarkers; Female; Humans; Malaria; Military Personnel; Population Surveillance; Pregnancy; United States
PubMed: 36048717
DOI: 10.15585/mmwr.ss7108a1