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1.
Viruses ; 14(6)2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35746601

RESUMO

The Incompatible Insect Technique (IIT) strategy involves the release of male mosquitoes infected with the bacterium Wolbachia. Regular releases of male Wolbachia-infected mosquitoes can lead to the suppression of mosquito populations, thereby reducing the risk of transmission of vector-borne diseases such as dengue. However, due to imperfect sex-sorting under IIT, fertile Wolbachia-infected female mosquitoes may potentially be unintentionally released into the environment, which may result in replacement and failure to suppress the mosquito populations. As such, mitigating Wolbachia establishment requires a combination of IIT with other strategies. We introduced a simple compartmental model to simulate ex-ante mosquito population dynamics subjected to a Wolbachia-IIT programme. In silico, we explored the risk of replacement, and strategies that could mitigate the establishment of the released Wolbachia strain in the mosquito population. Our results suggest that mitigation may be achieved through the application of a sterile insect technique. Our simulations indicate that these interventions do not override the intended wild type suppression of the IIT approach. These findings will inform policy makers of possible ways to mitigate the potential establishment of Wolbachia using the IIT population control strategy.


Assuntos
Aedes , Wolbachia , Aedes/microbiologia , Animais , Feminino , Masculino , Controle de Mosquitos/métodos , Mosquitos Vetores/microbiologia , Dinâmica Populacional
2.
Parasit Vectors ; 15(1): 191, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35668540

RESUMO

BACKGROUND: Dengue is a mosquito-borne viral disease that is mainly spread by Aedes aegypti. It is prevalent on five continents, predominantly in tropical and sub-tropical zones across the world. Wolbachia bacteria have been extensively used in vector control strategies worldwide. The focus of the current study was to obtain a natural population of Ae. aegypti harbouring Wolbachia and to determine the impact of this bacteria on the new host in a semi-field environment. METHODS: Wolbachia-infected Aedes albopictus was collected from the city of Lahore, Punjab, Pakistan, and Wolbachia were successfully introduced into laboratory-reared Ae. aegypti via embryonic microinjection. The stable vertical transmission of wAlbB in the host population was observed for eight generations, and the impact of Wolbachia on the general fitness of the host was evaluated in semi-field conditions. RESULTS: In the laboratory and semi-field experiments, wAlbB Wolbachia presented a strong cytoplasmic incompatibility (CI) effect, evidenced as zero egg hatching, in crosses between Wolbachia-infected males and wild (uninfected) females of Ae. aegypti. Wolbachia infection had no noticeable impact on the general fitness (P > 0.05), fecundity, body size (females and males) and mating competitiveness of the new host, Ae. aegypti. However, there was a significant decrease in female fertility (egg hatch) (P < 0.001). In addition, under starvation conditions, there was a remarkable decrease (P < 0.0001) in the life span of Wolbachia-infected females compared to uninfected females (4 vs. > 5 days, respectively). CONCLUSIONS: Wolbachia strain wAlbB has a great potential to control the dengue vector in Ae. aegypti populations by producing 100% CI with a limited burden on its host in natural field conditions. This strain can be used as a biological tool against vector-borne diseases.


Assuntos
Aedes , Dengue , Wolbachia , Aedes/microbiologia , Animais , Dengue/prevenção & controle , Feminino , Masculino , Microinjeções , Mosquitos Vetores/microbiologia , Paquistão , Controle Biológico de Vetores
3.
Insect Biochem Mol Biol ; 146: 103776, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35526745

RESUMO

Wolbachia pipientis is a maternally transmitted bacterium that mostly colonizes arthropods, including the mosquito Aedes fluviatilis, potentially affecting different aspects of host physiology. This intracellular bacterium prefers gonadal tissue cells, interfering with the reproductive cycle of insects, arachnids, crustaceans, and nematodes. Wolbachia's ability to modulate the host's reproduction is related to its success in prevalence and frequency. Infecting oocytes is essential for vertical propagation, ensuring its presence in the germline. The mosquito Ae. fluviatilis is a natural host for this bacterium and therefore represents an excellent experimental model in the effort to understand host-symbiont interactions and the mutual metabolic regulation. The aim of this study was to comparatively describe metabolic changes in naturally Wolbachia-infected and uninfected ovaries of Ae. fluviatilis during the vitellogenic period of oogenesis, thus increasing the knowledge about Wolbachia parasitic/symbiotic mechanisms.


Assuntos
Aedes , Wolbachia , Aedes/microbiologia , Animais , Oogênese , Simbiose/fisiologia , Wolbachia/fisiologia
4.
Chaos ; 32(4): 041105, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35489839

RESUMO

Over the last decade, the release of Wolbachia-infected Aedes aegypti into the natural habitat of this mosquito species has become the most sustainable and long-lasting technique to prevent and control vector-borne diseases, such as dengue, zika, or chikungunya. However, the limited resources to generate such mosquitoes and their effective distribution in large areas dominated by the Aedes aegypti vector represent a challenge for policymakers. Here, we introduce a mathematical framework for the spread of dengue in which competition between wild and Wolbachia-infected mosquitoes, the cross-contagion patterns between humans and vectors, the heterogeneous distribution of the human population in different areas, and the mobility flows between them are combined. Our framework allows us to identify the most effective areas for the release of Wolbachia-infected mosquitoes to achieve a large decrease in the global dengue prevalence.


Assuntos
Aedes/microbiologia , Febre de Chikungunya/prevenção & controle , Dengue/prevenção & controle , Mosquitos Vetores/microbiologia , Wolbachia/fisiologia , Infecção por Zika virus/prevenção & controle , Animais , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/transmissão , Dengue/epidemiologia , Dengue/transmissão , Humanos , Controle de Mosquitos/economia , Wolbachia/crescimento & desenvolvimento , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão
5.
Parasit Vectors ; 15(1): 67, 2022 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-35209944

RESUMO

BACKGROUND: Releasing considerable numbers of radiation-sterilized males is a promising strategy to suppress mosquito vectors. However, releases may also include small percentages of biting females, which translate to non-negligible numbers when releases are large. Currently, the effects of irradiation on host-seeking and host-biting behaviors have not been exhaustively investigated. Information is also lacking regarding the effects of sterilizing treatment on the endosymbiotic bacterium Wolbachia, which is known to affect the vector competence of infected mosquitos. METHODS: To ascertain the effects of irradiation on females, the pupae of two Aedes albopictus strains, differing in their natural or artificial Wolbachia infection type, and Aedes aegypti-which is not infected by Wolbachia-were treated with various doses of X-rays and monitored for key fitness parameters and biting behavior over a period of 2 weeks. The effect of radiation on Wolbachia was investigated by quantitative polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FISH) analysis. RESULTS: Partial Aedes albopictus female sterility was achieved at 28 Gy, but the number of weekly bites more than doubled compared to that of the controls. Radiation doses of 35 and 45 Gy completely inhibited progeny production but did not significantly affect the survival or flight ability of Ae. albopictus females and caused a tripling of the number of bites per female per week (compared to untreated controls). These results were also confirmed in Ae. aegypti after treatment at 50 Gy. Wolbachia density decreased significantly in 45-Gy-irradiated females, with the greatest decreases in the early irradiation group (26 ± 2-h-old pupae). Wolbachia density also decreased as adults aged. This trend was confirmed in ovaries but not in extra-ovarian tissues. FISH analysis showed a strongly reduced Wolbachia-specific fluorescence in the ovaries of 13 ± 1-day-old females. CONCLUSIONS: These results suggest that, under sterile insect technique (SIT) programs, the vector capacity of a target population could increase with the frequency of the irradiated females co-released with the sterile males due to an increased biting rate. In the context of successful suppression, the related safety issues are expected to be generally negligible, but they should be conservatively evaluated when large-scale programs relying on imperfect sexing and high overflooding release ratios are run for long periods in areas endemic for arboviral diseases. Also, the effects of irradiation on the vector competence deserve further investigation.


Assuntos
Aedes , Infertilidade Masculina , Wolbachia , Aedes/microbiologia , Animais , Feminino , Hibridização in Situ Fluorescente , Masculino , Controle de Mosquitos/métodos , Wolbachia/genética
6.
FEMS Microbiol Ecol ; 98(1)2022 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-35147188

RESUMO

Mosquito larvae are naturally exposed to microbial communities present in a variety of larval development sites. Several earlier studies have highlighted that the larval habitat influences the composition of the larval bacterial microbiota. However, little information is available on their fungal microbiota, i.e. the mycobiota. In this study, we provide the first simultaneous characterization of the bacterial and fungal microbiota in field-collected Aedes aegypti larvae and their respective aquatic habitats. We evaluated whether the microbial communities associated with the breeding site may affect the composition of both the bacterial and fungal communities in Ae. aegypti larvae. Our results show a higher similarity in microbial community structure for both bacteria and fungi between larvae and the water in which larvae develop than between larvae from different breeding sites. This supports the hypothesis that larval habitat is a major factor driving microbial composition in mosquito larvae. Since the microbiota plays an important role in mosquito biology, unravelling the network of interactions that operate between bacteria and fungi is essential to better understand the functioning of the mosquito holobiont.


Assuntos
Aedes , Microbiota , Micobioma , Aedes/microbiologia , Animais , Bactérias/genética , Larva/microbiologia , Mosquitos Vetores/microbiologia , Melhoramento Vegetal
7.
J Invertebr Pathol ; 189: 107730, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35124068

RESUMO

Wolbachia is a genus of gram-negative endosymbiotic bacterium of maternal transmission, located mainly in the gonads of arthropods, including mosquitoes such as Aedes albopictus. The current distribution of Ae. albopictus in Argentina is restricted to the subtropical northeastern region of the country. Here, we studied the seasonal prevalence of Wolbachia detected in Ae. albopictus larvae and the relationship between the abiotic factors of the larval microhabitat and the infection status, in Eldorado city, Misiones province, subtropical region. The prevalence of Wolbachia infection found was 76.89% (n = 312). From the total samples examined, 52.80% (n = 214) showed double infection with the wAlbA/wAlbB strains, 23.84% (n = 97) infection only with wAlbB, and 0.25% (n = 1) only with wAlbA. The prevalence of double infection did not present statistically significant differences between the sites studied. For single infection, the lowest prevalence value of the wAlbB strain (13.33%) was found in the natural park, whereas the highest was found in the family dwellings and cemeteries. Tire repair shops showed an intermediate value. The wAlbA single infection was identified once. Our results also showed an association between temperature and slightly turbid waters with exposure to the sun in the larval habitats and the probability of infection by Wolbachia.


Assuntos
Aedes , Rickettsiaceae , Wolbachia , Aedes/microbiologia , Animais , Prevalência , Simbiose
8.
PLoS Negl Trop Dis ; 16(1): e0010084, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35015769

RESUMO

Dengue fever is one of the most severe viral diseases transmitted by Aedes mosquitoes, with traditional approaches of disease control proving insufficient to prevent significant disease burden. Release of Wolbachia-transinfected mosquitoes offers a promising alternative control methodologies; Wolbachia-transinfected female Aedes aegypti demonstrate reduced dengue virus transmission, whilst Wolbachia-transinfected males cause zygotic lethality when crossed with uninfected females, providing a method for suppressing mosquito populations. Although highly promising, the delicate nature of population control strategies and differences between local species populations means that controlled releases of Wolbachia-transinfected mosquitoes cannot be performed without extensive testing on specific local Ae. aegypti populations. In order to investigate the potential for using Wolbachia to suppress local Ae. aegypti populations in Taiwan, we performed lab-based and semi-field fitness trials. We first transinfected the Wolbachia strain wAlbB into a local Ae. aegypti population (wAlbB-Tw) and found no significant changes in lifespan, fecundity and fertility when compared to controls. In the laboratory, we found that as the proportion of released male mosquitoes carrying Wolbachia was increased, population suppression could reach up to 100%. Equivalent experiments in semi-field experiments found suppression rates of up to 70%. The release of different ratios of wAlbB-Tw males in the semi-field system provided an estimate of the optimal size of male releases. Our results indicate that wAlbB-Tw has significant potential for use in vector control strategies aimed at Ae. aegypti population suppression in Taiwan. Open field release trials are now necessary to confirm that wAlbB-Tw mediated suppression is feasible in natural environments.


Assuntos
Aedes/microbiologia , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Controle Biológico de Vetores/métodos , Wolbachia/metabolismo , Animais , Agentes de Controle Biológico/administração & dosagem , Dengue/transmissão , Vírus da Dengue/isolamento & purificação , Feminino , Masculino , Mosquitos Vetores/virologia , Taiwan , Wolbachia/classificação , Zigoto/microbiologia
9.
J Gen Virol ; 103(1)2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35006065

RESUMO

Mosquito-borne flaviviruses are responsible for viral infections and represent a considerable public health burden. Aedes aegypti is the principal vector of dengue virus (DENV), therefore understanding the intrinsic virus-host interactions is vital, particularly in the presence of the endosymbiont Wolbachia, which blocks virus replication in mosquitoes. Here, we examined the transcriptional response of Wolbachia-transinfected Ae. aegypti Aag2 cells to DENV infection. We identified differentially expressed immune genes that play a key role in the activation of anti-viral defence such as the Toll and immune deficiency pathways. Further, genes encoding cytosine and N6-adenosine methyltransferases and SUMOylation, involved in post-transcriptional modifications, an antioxidant enzyme, and heat-shock response were up-regulated at the early stages of DENV infection and are reported here for the first time. Additionally, several long non-coding RNAs were among the differentially regulated genes. Our results provide insight into Wolbachia-transinfected Ae. aegypti's initial virus recognition and transcriptional response to DENV infection.


Assuntos
Aedes/virologia , Vírus da Dengue/genética , Dengue/virologia , Wolbachia/fisiologia , Aedes/microbiologia , Animais , Vírus da Dengue/fisiologia , Interações entre Hospedeiro e Microrganismos , Humanos , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia , RNA Longo não Codificante , Sumoilação , Replicação Viral
10.
Microb Ecol ; 83(1): 167-181, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33797563

RESUMO

Host-microbiome dynamics occurring in the yellow fever mosquito (Aedes aegypti) contribute to host life history traits, and particular bacterial taxa are proposed to comprise a "core" microbiota that influences host physiology. Laboratory-based studies are frequently performed to investigate these processes; however, experimental results are often presumed to be generalizable across laboratories, and few efforts have been made to independently reproduce and replicate significant findings. A recent study by Muturi et al. (FEMS Microbiol Ecol 95 (1):213, 2019) demonstrated the food source imbibed by laboratory-reared adult female mosquitoes significantly impacted the host-associated microbiota-a foundational finding in the field of mosquito biology worthy of independent evaluation. Here, we coalesce these data with two additional mosquito-derived 16S rRNA gene sequence data sets using a unifying bioinformatics pipeline to reproduce the characterization of these microbiota, test for a significant food source effect when independent samples were added to the analyses, assess whether similarly fed mosquito microbiomes were comparable across laboratories, and identify conserved bacterial taxa. Our pipeline characterized similar microbiome composition and structure from the data published previously, and a significant food source effect was detected with the addition of independent samples, increasing the robustness of this previously discovered component of mosquito biology. However, distinct microbial communities were identified from similarly fed but independently reared mosquitoes, and surveys across all samples did not identify conserved bacterial taxa. These findings demonstrated that while the main effect of the food source was supported, laboratory-specific conditions may produce inherently differential microbiomes across independent laboratory environments.


Assuntos
Aedes , Microbiota , Aedes/microbiologia , Animais , Feminino , Microbiota/genética , RNA Ribossômico 16S/genética
11.
J Med Entomol ; 59(1): 390-393, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34665223

RESUMO

Mosquitoes are the most important vectors carrying significant numbers of human pathogens. Recent studies implicated that mosquitoes play an important role in circulation and transmission of multiple Rickettsia species. In this study, Rickettsia bellii was identified in four mosquito species (Culex pipiens, C. tritaeniorhynchus, Aedes albopictus, and Anopheles sinensis) collected from three Eastern China provinces during 2019-2020. Rickettsia bellii was detected in 37.50 and 26.32% of the C. pipiens pools from Beijing and Jiangsu province, respectively. In C. tritaeniorhynchus and An. sinensis from Shandong, the infection rate is 20.00 and 6.25%, respectively. Additionally, three Ae. albopictus pools (3/42, 7.14%) from Beijing were also detected positive for R. bellii. Genetic and phylogenetic analysis on 16S, gltA, and groEL genes indicates that sequences from all these strains are highly homologous and closely related to other R. bellii strains. This is the first report that Ae. albopictus and C. tritaeniorhynchus harbor R. bellii. The wide host range and high infection rate in certain areas may dramatically increase the exposure of R. bellii to human and other vertebrates. The role of mosquitoes in transmission of rickettsiosis and its potential risk to public health should be further considered.


Assuntos
Culicidae/microbiologia , Rickettsia/isolamento & purificação , Aedes/microbiologia , Animais , Anopheles/microbiologia , China/epidemiologia , Culex/microbiologia , Vetores de Doenças , Genes Bacterianos , Mosquitos Vetores/microbiologia , Filogenia , Prevalência , RNA Ribossômico 16S , Rickettsia/genética , Infecções por Rickettsia/transmissão
12.
Mol Ecol ; 31(5): 1444-1460, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34905257

RESUMO

In animals with distinct life stages such as holometabolous insects, adult phenotypic variation is often shaped by the environment of immature stages, including their interactions with microbes colonizing larval habitats. Such carry-over effects were previously observed for several adult traits of the mosquito Aedes aegypti after larval exposure to different bacteria, but the mechanistic underpinnings are unknown. Here, we investigated the molecular changes triggered by gnotobiotic larval exposure to different bacteria in Ae. aegypti. We initially screened a panel of 16 bacterial isolates from natural mosquito breeding sites to determine their ability to influence adult life-history traits. We subsequently focused on four bacterial isolates (belonging to Flavobacterium, Lysobacter, Paenibacillus, and Enterobacteriaceae) with significant carry-over effects on adult survival and found that they were associated with distinct transcriptomic profiles throughout mosquito development. Moreover, we detected carry-over effects at the level of gene expression for the Flavobacterium and Paenibacillus isolates. The most prominent transcriptomic changes in gnotobiotic larvae reflected a profound remodelling of lipid metabolism, which translated into phenotypic differences in lipid storage and starvation resistance at the adult stage. Together, our findings indicate that larval exposure to environmental bacteria trigger substantial physiological changes that impact adult fitness, uncovering a possible mechanism underlying carry-over effects of mosquito-bacteria interactions during larval development.


Assuntos
Aedes , Aedes/microbiologia , Animais , Bactérias/genética , Ecossistema , Larva/microbiologia
13.
PLoS Negl Trop Dis ; 15(12): e0009966, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34871301

RESUMO

Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health challenge in tropical regions. Wolbachia-mediated population suppression (Wolbachia suppression) is a vector control method used to reduce Aedes mosquito populations by introducing male mosquitoes infected with Wolbachia, a naturally occurring endosymbiotic bacterium. When Wolbachia-infected male mosquitoes mate with female wild mosquitoes, the resulting eggs will not hatch. Public support is vital to the successful implementation and sustainability of vector control interventions. Communities Organized to Prevent Arboviruses (COPA) is a cohort study to determine the incidence of arboviral disease in Ponce, Puerto Rico and evaluate vector control methods. Focus groups were conducted with residents of COPA communities to gather their opinion on vector control methods; during 2018-2019, adult COPA participants were interviewed regarding their views on Wolbachia suppression; and a follow-up questionnaire was conducted among a subset of participants and non-participants residing in COPA communities. We analyzed factors associated with support for this method. Among 1,528 participants in the baseline survey, median age was 37 years and 63% were female. A total of 1,032 (68%) respondents supported Wolbachia suppression. Respondents with an income of $40,000 or more were 1.34 times as likely [95% CI: 1.03, 1.37] to support Wolbachia suppression than those who earned less than $40,000 annually. Respondents who reported repellant use were 1.19 times as likely to support Wolbachia suppression [95% CI: 1.03, 1.37]. A follow-up survey in 2020 showed that most COPA participants (86%) and non-participants living in COPA communities (84%) supported Wolbachia suppression during and after an educational campaign. The most frequent questions regarding this method were related to its impact on human and animal health, and the environment. Continuous community engagement and education efforts before and during the implementation of novel vector control interventions are necessary to increase and maintain community support.


Assuntos
Aedes/microbiologia , Controle de Mosquitos/métodos , Mosquitos Vetores/microbiologia , Wolbachia/fisiologia , Adulto , Aedes/fisiologia , Animais , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/fisiologia , Comportamento Sexual Animal , Inquéritos e Questionários , Adulto Jovem
14.
Parasit Vectors ; 14(1): 592, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34852835

RESUMO

BACKGROUND: Aedes aegypti and Ae. albopictus are vectors of numerous arboviruses that adversely affect human health. In mosquito vectors of disease, the bacterial microbiota influence several physiological processes, including fertility and vector competence, making manipulation of the bacterial community a promising method to control mosquito vectors. In this study, we describe the reproductive tract tissue microbiota of lab-reared virgin Ae. aegypti and Ae. albopictus males, and virgin, mated, and mated + blood-fed females of each species, comparing the bacterial composition found there to the well-described gut microbiota. METHODS: We performed metabarcoding of the 16S rRNA isolated from the gut, upper reproductive tract (URT; testes or ovaries), and lower reproductive tract (LRT; males: seminal vesicles and accessory glands; females: oviduct, spermathecae, and bursa) for each species, and evaluated the influence of host species, tissue, nutritional status, and reproductive status on microbiota composition. Finally, based on the identified taxonomic profiles of the tissues assessed, bacterial metabolic pathway abundance was predicted. RESULTS: The community structure of the reproductive tract is unique compared to the gut. Asaia is the most prevalent OTU in the LRTs of both Ae. aegypti and Ae. albopictus. In the URT, we observed differences between species, with Wolbachia OTUs being dominant in the Ae. albopictus URT, while Enterobacter and Serratia were dominant in Ae. aegypti URT. Host species and tissue were the best predictors of the community composition compared to reproductive status (i.e., virgin or mated) and nutritional status (i.e., sugar or blood-fed). The predicted functional profile shows changes in the abundance of specific microbial pathways that are associated with mating and blood-feeding, like energy production in mated tissues and siderophore synthesis in blood-fed female tissues. CONCLUSIONS: Aedes aegypti and Ae. albopictus have distinct differences in the composition of microbiota found in the reproductive tract. The distribution of the bacterial taxonomic groups indicates that some bacteria have tissue-specific tropism for reproductive tract tissue, such as Asaia and Wolbachia. No significant differences in the taxonomic composition were observed in the reproductive tract between virgin, mated, and mated + blood-fed females, but changes in the abundance of specific metabolic pathways were found in the predicted microbial functional profiles in mated and blood-fed females.


Assuntos
Aedes/microbiologia , Bactérias/classificação , Microbiota , Mosquitos Vetores/parasitologia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Código de Barras de DNA Taxonômico , Feminino , Genitália/microbiologia , Humanos , Especificidade de Órgãos , RNA Bacteriano/genética , RNA Ribossômico 16S/genética
15.
Nat Microbiol ; 6(12): 1575-1582, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34819638

RESUMO

Wolbachia, a maternally inherited intracellular bacterial species, can manipulate host insect reproduction by cytoplasmic incompatibility (CI), which results in embryo lethality in crosses between infected males and uninfected females. CI is encoded by two prophage genes, cifA and cifB. Wolbachia, coupled with the sterile insect technique, has been used in field trials to control populations of the dengue vector Aedes albopictus, but CI-inducing strains are not known to infect the malaria vector Anopheles gambiae. Here we show that cifA and cifB can induce conditional sterility in the malaria vector An. gambiae. We used transgenic expression of these Wolbachia-derived genes in the An. gambiae germline to show that cifB is sufficient to cause embryonic lethality and that cifB-induced sterility is rescued by cifA expression in females. When we co-expressed cifA and cifB in male mosquitoes, the CI phenotype was attenuated. In female mosquitoes, cifB impaired fertility, which was overcome by co-expression of cifA. Our findings pave the way towards using CI to control malaria mosquito vectors.


Assuntos
Anopheles/microbiologia , Anopheles/fisiologia , Proteínas de Bactérias/metabolismo , Herança Extracromossômica , Mosquitos Vetores/microbiologia , Mosquitos Vetores/fisiologia , Wolbachia/metabolismo , Aedes/genética , Aedes/microbiologia , Aedes/fisiologia , Animais , Anopheles/genética , Proteínas de Bactérias/genética , Feminino , Infertilidade Masculina , Malária/transmissão , Masculino , Mosquitos Vetores/genética , Wolbachia/genética
16.
Parasit Vectors ; 14(1): 586, 2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34838108

RESUMO

BACKGROUND: Aedes aegypti and Aedes albopictus are invasive mosquito species and significantly impact human health in southern China. Microbiota are confirmed to affect the development and immunity of mosquitoes. However, scientists have focused more on midgut microbiota of female mosquitoes and bacterial differences between female and male Aedes mosquitoes. The relationship between the midgut and entire body microbiota of Aedes is unclear. In this study, we collected mosquito samples reared under the same laboratory conditions and compared the microbial composition of midgut and entire bodies of Aedes aegypti and Aedes albopictus using 16S rRNA gene sequencing. METHODS: In this study, we collected mosquito samples reared under the same laboratory conditions and compared the microbial composition of midgut and entire bodies of Aedes aegypti and Aedes albopictus using 16S rRNA gene sequencing. RESULTS: A total of 341 OTUs were identified, showing that Proteobacteria was the dominant phylum and Methylobacterium the dominant genus in both Aedes aegypti and Aedes albopictus. The bacterial diversity and community structures of the entire bodies were similar between males and females in both Aedes aegypti and Aedes albopictus. Conversely, the bacterial compositions of male and female Aedes aegypti and Aedes albopictus were significantly different. NMDS analysis, UPGMA analysis, diversity indices and OTU distribution demonstrated that compositions and structures in midgut microbiota were similar but significantly different in the entire bodies of Aedes aegypti and Aedes albopictus. Functional prediction analysis showed that metabolism and environmental information processing were the dominant KEGG pathways at level 1. Our study showed that there were significantly different level 2 and 3 KEGG pathways in the midgut microbiota (16 level 2 and 24 level 3) and the entire bodies (33 level 2 and 248 level 3) between female Aedes albopictus and Aedes Aegypti. CONCLUSIONS: Our findings that Aedes aegypti and Aedes albopictus reared in the same laboratory harbor a similar gut bacterial microbiome but different entire body microbiota imply that the gut microbiota of adult mosquitoes is environmentally determined regardless of the host genotype, but the entire body microbiota is more genetically determined. Our findings improved the understanding of the microbiota in the entire and partial tissues of Aedes mosquitoes.


Assuntos
Aedes/microbiologia , Bactérias , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , China , Microbioma Gastrointestinal/genética , Sequenciamento de Nucleotídeos em Larga Escala , Laboratórios , Metagenômica , Mosquitos Vetores/microbiologia , RNA Ribossômico 16S/genética
17.
PLoS Negl Trop Dis ; 15(11): e0009984, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34843477

RESUMO

Microbial control of mosquitoes via the use of symbiotic or pathogenic microbes, such as Wolbachia and entomopathogenic fungi, are promising alternatives to synthetic insecticides to tackle the rapid increase in insecticide resistance and vector-borne disease outbreaks. This study evaluated the susceptibility and host responses of two important mosquito vectors, Ae. albopictus and Cx. pipiens, that naturally carry Wolbachia, to infections by entomopathogenic fungi. Our study indicated that while Wolbachia presence did not provide a protective advantage against entomopathogenic fungal infection, it nevertheless influenced the bacterial / fungal load and the expression of select anti-microbial effectors and phenoloxidase cascade genes in mosquitoes. Furthermore, although host responses from Ae. albopictus and Cx. pipiens were mostly similar, we observed contrasting phenotypes with regards to susceptibility and immune responses to fungal entomopathogenic infection in these two mosquitoes. This study provides new insights into the intricate multipartite interaction between the mosquito host, its native symbiont and pathogenic microbes that might be employed to control mosquito populations.


Assuntos
Aedes/imunologia , Culex/imunologia , Imunidade/genética , Mosquitos Vetores/imunologia , Wolbachia/genética , Aedes/efeitos dos fármacos , Aedes/genética , Aedes/microbiologia , Animais , Culex/efeitos dos fármacos , Culex/genética , Culex/microbiologia , Fungos , Expressão Gênica , Resistência a Inseticidas , Inseticidas , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Mosquitos Vetores/microbiologia , Simbiose , Doenças Transmitidas por Vetores
18.
mBio ; 12(6): e0025021, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34749528

RESUMO

Environmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of Wolbachia symbionts for the control of dengue arboviruses. The potential of Wolbachia to invade, persist, and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating Wolbachia densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on Wolbachia density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains wMel and wAlbB, two Wolbachia strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity, and dengue inhibition capacity were observed for wMel. In contrast, wAlbB-carrying Ae. aegypti maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, wMel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures. IMPORTANCE In the past decades, dengue incidence has dramatically increased all over the world. An emerging dengue control strategy utilizes Aedes aegypti mosquitoes artificially transinfected with the bacterial symbiont Wolbachia, with the ultimate aim of replacing wild mosquito populations. However, the rearing temperature of mosquito larvae is known to impact on some Wolbachia strains. In this study, we compared the effects of a temperature cycle mimicking natural breeding sites in tropical climates on two Wolbachia strains, currently used for open field trials. When choosing the Wolbachia strain to be used in a dengue control program it is important to consider the effects of environmental temperatures on invasiveness and virus inhibition. These results underline the significance of understanding the impact of environmental factors on released mosquitoes, in order to ensure the most efficient strategy for dengue control.


Assuntos
Aedes/microbiologia , Larva/crescimento & desenvolvimento , Mosquitos Vetores/microbiologia , Wolbachia/fisiologia , Aedes/crescimento & desenvolvimento , Aedes/virologia , Animais , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/fisiologia , Ecossistema , Feminino , Humanos , Larva/microbiologia , Larva/virologia , Masculino , Controle de Mosquitos , Mosquitos Vetores/crescimento & desenvolvimento , Mosquitos Vetores/virologia , Dinâmica Populacional , Temperatura , Wolbachia/genética
19.
Sci Rep ; 11(1): 21355, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34725401

RESUMO

The mosquito Aedes aegypti is the major vector of arboviruses like dengue, Zika and chikungunya viruses. Attempts to reduce arboviruses emergence focusing on Ae. aegypti control has proven challenging due to the increase of insecticide resistances. An emerging strategy which consists of releasing Ae. aegypti artificially infected with Wolbachia in natural mosquito populations is currently being developed. The monitoring of Wolbachia-positive Ae. aegypti in the field is performed in order to ensure the program effectiveness. Here, the reliability of the Matrix­Assisted Laser Desorption Ionization­Time Of Flight (MALDI­TOF) coupled with the machine learning methods like Convolutional Neural Network (CNN) to detect Wolbachia in field Ae. aegypti was assessed for the first time. For this purpose, laboratory reared and field Ae. aegypti were analyzed. The results showed that the CNN recognized Ae. aegypti spectral patterns associated with Wolbachia-infection. The MALDI-TOF coupled with the CNN (sensitivity = 93%, specificity = 99%, accuracy = 97%) was more efficient than the loop-mediated isothermal amplification (LAMP), and as efficient as qPCR for Wolbachia detection. It therefore represents an interesting method to evaluate the prevalence of Wolbachia in field Ae. aegypti mosquitoes.


Assuntos
Aedes/microbiologia , Mosquitos Vetores/microbiologia , Wolbachia/isolamento & purificação , Animais , Inteligência Artificial , Controle de Mosquitos/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Wolbachia/química
20.
Parasit Vectors ; 14(1): 573, 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34772442

RESUMO

BACKGROUND: Vector-borne pathogens must survive and replicate in the hostile environment of an insect's midgut before successful dissemination. Midgut microbiota interfere with pathogen infection by activating the basal immunity of the mosquito and by synthesizing pathogen-inhibitory metabolites. METHODS: The goal of this study was to assess the influence of Zika virus (ZIKV) infection and increased temperature on Aedes albopictus midgut microbiota. Aedes albopictus were reared at diurnal temperatures of day 28 °C/night 24 °C (L) or day 30 °C/night 26 °C (M). The mosquitoes were given infectious blood meals with 2.0 × 108 PFU/ml ZIKV, and 16S rRNA sequencing was performed on midguts at 7 days post-infectious blood meal exposure. RESULTS: Our findings demonstrate that Elizabethkingia anophelis albopictus was associated with Ae. albopictus midguts exposed to ZIKV infectious blood meal. We observed a negative correlation between ZIKV and E. anophelis albopictus in the midguts of Ae. albopictus. Supplemental feeding of Ae. albopictus with E. anophelis aegypti and ZIKV resulted in reduced ZIKV infection rates. Reduced viral loads were detected in Vero cells that were sequentially infected with E. anophelis aegypti and ZIKV, dengue virus (DENV), or chikungunya virus (CHIKV). CONCLUSIONS: Our findings demonstrate the influence of ZIKV infection and temperature on the Ae. albopictus microbiome along with a negative correlation between ZIKV and E. anophelis albopictus. Our results have important implications for controlling vector-borne pathogens.


Assuntos
Aedes/microbiologia , Aedes/virologia , Flavobacteriaceae/fisiologia , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia , Zika virus/fisiologia , Animais , Flavobacteriaceae/genética , Humanos , Temperatura , Zika virus/genética , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
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