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1.
PLoS Negl Trop Dis ; 18(4): e0012053, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38557981

ABSTRACT

BACKGROUND: Mosquito-borne arboviruses are expanding their territory and elevating their infection prevalence due to the rapid climate change, urbanization, and increased international travel and global trade. Various significant arboviruses, including the dengue virus, Zika virus, Chikungunya virus, and yellow fever virus, are all reliant on the same primary vector, Aedes aegypti. Consequently, the occurrence of arbovirus coinfection in mosquitoes is anticipated. Arbovirus coinfection in mosquitoes has two patterns: simultaneous and sequential. Numerous studies have demonstrated that simultaneous coinfection of arboviruses in mosquitoes is unlikely to exert mutual developmental influence on these viruses. However, the viruses' interplay within a mosquito after the sequential coinfection seems intricated and not well understood. METHODOLOGY/PRINCIPAL FINDINGS: We conducted experiments aimed at examining the phenomenon of arbovirus sequential coinfection in both mosquito cell line (C6/36) and A. aegypti, specifically focusing on dengue virus (DENV, serotype 2) and Zika virus (ZIKV). We firstly observed that DENV and ZIKV can sequentially infect mosquito C6/36 cell line, but the replication level of the subsequently infected ZIKV was significantly suppressed. Similarly, A. aegypti mosquitoes can be sequentially coinfected by these two arboviruses, regardless of the order of virus exposure. However, the replication, dissemination, and the transmission potential of the secondary virus were significantly inhibited. We preliminarily explored the underlying mechanisms, revealing that arbovirus-infected mosquitoes exhibited activated innate immunity, disrupted lipid metabolism, and enhanced RNAi pathway, leading to reduced susceptibility to the secondary arbovirus infections. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that, in contrast to simultaneous arbovirus coinfection in mosquitoes that can promote the transmission and co-circulation of these viruses, sequential coinfection appears to have limited influence on arbovirus transmission dynamics. However, it is important to note that more experimental investigations are needed to refine and expand upon this conclusion.


Subject(s)
Aedes , Arboviruses , Coinfection , Dengue Virus , Dengue , Zika Virus Infection , Zika Virus , Animals , Coinfection/epidemiology , Mosquito Vectors , Dengue/epidemiology
2.
Nat Commun ; 15(1): 1980, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38438367

ABSTRACT

The sterile insect technique is based on the overflooding of a target population with released sterile males inducing sterility in the wild female population. It has proven to be effective against several insect pest species of agricultural and veterinary importance and is under development for Aedes mosquitoes. Here, we show that the release of sterile males at high sterile male to wild female ratios may also impact the target female population through mating harassment. Under laboratory conditions, male to female ratios above 50 to 1 reduce the longevity of female Aedes mosquitoes by reducing their feeding success. Under controlled conditions, blood uptake of females from an artificial host or from a mouse and biting rates on humans are also reduced. Finally, in a field trial conducted in a 1.17 ha area in China, the female biting rate is reduced by 80%, concurrent to a reduction of female mosquito density of 40% due to the swarming of males around humans attempting to mate with the female mosquitoes. This suggests that the sterile insect technique does not only suppress mosquito vector populations through the induction of sterility, but may also reduce disease transmission due to increased female mortality and lower host contact.


Subject(s)
Aedes , Infertility, Male , Humans , Female , Male , Animals , Mice , Reproduction , Cell Communication , Insecta
3.
Pest Manag Sci ; 79(11): 4186-4196, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37318795

ABSTRACT

BACKGROUND: The sterile insect technique (SIT) is a green and species-specific insect pest control technique that suppresses target populations by releasing factory-reared, radiosterilized males into the wild. Once released, it is important to be able to distinguish the released males from the wild males for monitoring purposes. Several methods to mark the sterile males exist. However, most have limitations due to monetary, process efficiency, or insect quality. Aedes albopictus is naturally infected with Wolbachia at a high prevalence, therefore the elimination of Wolbachia can serve as a biomarker to distinguish factory-reared male mosquitoes from wild conspecifics. RESULTS: In this study, a Wolbachia-free Ae. albopictus GT strain was developed and its fitness evaluated, which was found to be comparable to the wild GUA strain. In addition, GT male mosquitoes were irradiated at the adult stage and a dose of 20 Gy or more induced over 99% sterility. Moreover, a dose of 30 Gy (almost completely sterilizing male and female mosquitoes) had limited effects on the mating competitiveness of GT males and the vector competence of GT females, respectively. However, radiation reduced mosquito longevity, regardless of sex. CONCLUSION: Our results indicate that the Ae. albopictus GT strain can be distinguished from wild mosquitoes based on Wolbachia status and shows similar fitness, radio-sensitivity and arbovirus susceptibility to the GUA strain, indicating that it is feasible to use the GT strain to suppress Ae. albopictus populations for SIT programmes. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

4.
Trop Med Infect Dis ; 7(12)2022 Dec 12.
Article in English | MEDLINE | ID: mdl-36548686

ABSTRACT

The geographic boundaries of arboviruses continue to expand, posing a major health threat to millions of people around the world. This expansion is related to the availability of effective vectors and suitable habitats. Armigeres subalbatus (Coquillett, 1898), a common and neglected species, is of increasing interest given its potential vector capacity for Zika virus. However, potential distribution patterns and the underlying driving factors of Ar. subalbatus remain unknown. In the current study, detailed maps of their potential distributions were developed under both the current as well as future climate change scenarios (SSP126 and SSP585) based on CMIP6 data, employing the MaxEnt model. The results showed that the distribution of the Ar. subalbatus was mainly affected by temperature. Mean diurnal range was the strongest predictor in shaping the distribution of Ar. subalbatus, with an 85.2% contribution rate. By the 2050s and 2070s, Ar. subalbatus will have a broader potential distribution across China. There are two suitable expansion types under climate change in the 2050s and 2070s. The first type is continuous distribution expansion, and the second type is sporadic distribution expansion. Our comprehensive analysis of Ar. subalbatus's suitable distribution areas shifts under climate change and provides useful and insightful information for developing management strategies for future arboviruses.

5.
Front Public Health ; 10: 923277, 2022.
Article in English | MEDLINE | ID: mdl-35968472

ABSTRACT

Background: Dengue fever has been responsible for around 12 countrywide large outbreaks in Pakistan, resulting in 286,262 morbidities and 1,108 deaths. Khyber Pakhtunkhwa (KP) is the most recently impacted province. This study aimed to investigate the molecular, epidemiological, and potential elements that contribute to increasing dengue transmission patterns, and knowledge, attitude, and practice (KAP) toward dengue in KP province. Method: This cross-sectional community-based study was conducted (June-December, 2021) in two phases. Phase I involved the epidemiological (n = 5,242) and molecular analysis of DENV in 500 randomly collected blood samples of the 2021 dengue outbreak in KP. Phase II focused on assessing dengue-KAP levels in healthy communities (n = 14,745, aged >18 years), adopting a cross-sectional clustered multistage sampling in eight districts (dengue-hotspot vs. non-hotspot) of KP. Chi-square tests and logistic regression analysis were applied. Results: Peshawar district had the highest dengue cases (60.0%) associated with the predominant co-circulation of DENV-2 (45.8%) and DENV-3 (50.4%) serotypes. A rise in cases was reported in October (41.8%) followed by September (27.9%) and August (14.4%; p < 0.001). Males (63.7%, p < 0.001) and individuals aged 16-30 years (37.0%, p < 0.001) were highly affected. General workers (18.0%), families with a monthly income of 10,000-20,000 Pak rupees (50.5%), unmarried (71.0%), uneducated (31%), families with higher human density (>10 individuals per household), and those (29.0%) who faced power outages for more than 7/24 h were the most affected. Moreover, co-morbidities like renal failure and bronchial asthma were associated with disease severity. A community survey on KAP revealed that an average of 74, 60, and 43% of the participants demonstrated good knowledge, attitudes, and dengue preventive practices, respectively. Conclusion: Multiple poor socioeconomic elements are influencing dengue fever transmission in the province. Higher KAP levels may explain the low frequency of dengue in non-hotspot districts. Our study emphasizes the need for effective and long-term public health education, strengthened vector surveillance, and expanded laboratory capacity for better diagnosis and management of dengue cases to better predict the burden and seasonality of disease in the country.


Subject(s)
Dengue , Cross-Sectional Studies , Dengue/diagnosis , Dengue/epidemiology , Dengue/prevention & control , Health Knowledge, Attitudes, Practice , Humans , Male , Pakistan/epidemiology , Risk Factors
6.
Insects ; 13(6)2022 Jun 10.
Article in English | MEDLINE | ID: mdl-35735869

ABSTRACT

The sterile insect technique (SIT) and its related technologies are considered to be a powerful weapon for fighting against mosquitoes. As an important part of the area-wide integrated pest management (AW-IPM) programs, SIT can help reduce the use of chemical pesticides for mosquito control, and consequently, the occurrence of insecticide resistance. The mosquito SIT involves several important steps, including mass rearing, sex separation, irradiation, packing, transportation, release and monitoring. To enable the application of SIT against mosquitoes to reduce vector populations, the Joint Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA) Centre (previously called Division) of Nuclear Techniques in Food and Agriculture (hereinafter called Joint FAO/IAEA Centre) and its Insects Pest Control sub-program promoted a coordinated research project (CRP) entitled "Mosquito handling, transport, release and male trapping methods" to enhance the success of SIT. This article summarizes the existing explorations that are critical to the handling and transporting of male mosquitoes, offers an overview of detailed steps in SIT and discusses new emerging methods for mosquito releases, covering most processes of SIT.

7.
Foods ; 11(11)2022 May 26.
Article in English | MEDLINE | ID: mdl-35681318

ABSTRACT

Sarcodon aspratus is a popular edible fungus for its tasty flavour and can be used as a dietary supplement for its functional substances. This study was conducted to evaluate the potential health benefits of Sarcodon aspratus polysaccharides (SAFP) on water immersion and restraint stress (WIRS)-induced gastric ulcer in rats. The results indicated that SAFP could decrease myeloperoxidase (MPO) activity and plasma corticosterone levels, as well as enhance Prostaglandin E2 (PGE2) and Nitrate/nitrite (NOx) concentration in rats. Furthermore, SAFP significantly attenuated the stress damage, inflammation, pathological changes and gastric mucosal lesion in rats. Moreover, high-throughput pyrosequencing of 16S rRNA suggested that SAFP modulated the dysbiosis of gut microbiota by enhancing the relative abundance of probiotics, decreasing WIRS-triggered bacteria proliferation. In summary, these results provided the evidence that SAFP exerted a beneficial effect on a WIRS-induced gastric ulcer via blocking the TLR4 signaling pathway and activating the Nrf2 signaling pathway. Notably, SAFP could modulate the WIRS-induced dysbiosis of gut microbiota. Thus, SAFP might be explored as a natural gastric mucosal protective agent in the prevention of gastric ulcers and other related diseases in the food and pharmaceutical industries.

8.
Front Nutr ; 9: 902208, 2022.
Article in English | MEDLINE | ID: mdl-35711553

ABSTRACT

In this study, lycopene was successfully encapsulated in polyelectrolyte complex nanoparticles (PEC NPs) fabricated with a negatively charged polysaccharide, TLH-3, and a positively charged sodium caseinate (SC) via electrostatic interactions. Results showed that the lycopene-loaded PEC NPs were spherical in shape, have a particle size of 241 nm, have a zeta potential of -23.6 mV, and have encapsulation efficiency of 93.6%. Thus, lycopene-loaded PEC NPs could serve as effective lycopene carriers which affected the physicochemical characteristics of the encapsulated lycopene and improved its water dispersibility, storage stability, antioxidant capacity, and sustained release ability in aqueous environments when compared with the free lycopene. Moreover, encapsulated lycopene could enhance the cells' viability, prevent cell apoptosis, and protect cells from oxidative damage through the Nrf2/HO-1/AKT signalling pathway, via upregulation of antioxidase activities and downregulation of MDA and ROS levels. Therefore, the biocompatible lycopene-loaded PEC NPs have considerable potential use for the encapsulation of hydrophobic nutraceuticals in the food and pharmaceutical industries.

9.
Angew Chem Int Ed Engl ; 61(29): e202203541, 2022 07 18.
Article in English | MEDLINE | ID: mdl-35499863

ABSTRACT

Several γ-cyclodextrin (CD) derivatives mono- or di-substituted by pyrenes at the primary rim of the CD were demonstrated to aggregate into nano-strips in aqueous solutions, with the pyrene moieties interpenetrating into γ-CD cavities. The hydrophobic complexation-induced aggregation provides a rigid chiral environment for the pyrenes and leads to significant electronic circular dichroism (ECD) and circularly polarized luminescence (CPL) activities, giving unprecedently high gabs and glum values up to 4.3×10-2 and 5.3×10-2 , respectively. The aggregates lead to excimer emission with high quantum yields and show BCPL and BiCPL up to 338. 6 M-1 cm-1 and 169.3 M-1 cm-1 , respectively.


Subject(s)
Cyclodextrins , Luminescence , Circular Dichroism , Electronics , Pyrenes/chemistry
10.
ACS Appl Mater Interfaces ; 14(18): 21453-21460, 2022 May 11.
Article in English | MEDLINE | ID: mdl-35486103

ABSTRACT

Singlet chiral photocatalysis is highly challenging. Herein, we report fluorescence resonance energy transfer (FRET)-based chiral photocatalysis with γ-cyclodextrin (CD)-grafted lanthanide-doped upconverted nanoparticles (UCNP). The CD-modified UCNP strongly emits in the UV wavelength region upon excitation with a 980 nm laser, which selectively sensitizes the photosubstrates complexed by CD on the surface of UCNP through FRET. Therefore, enantiodifferentiating photocyclodimerization of anthracene or naphthalene derivatives sensitized by the CD-modified UCNP gives photoproducts in good enantioselectivity even in the presence of a catalytic amount of CD-modified UCNP. Moreover, the photocatalysts are readily separated and could be reused for at least six cycles without decreasing the enantioselectivity.

11.
PLoS Negl Trop Dis ; 16(4): e0010324, 2022 04.
Article in English | MEDLINE | ID: mdl-35471983

ABSTRACT

BACKGROUND: The combination of Wolbachia-based incompatible insect technique (IIT) and radiation-based sterile insect technique (SIT) can be used for population suppression of Aedes aegypti. Our main objective was to evaluate whether open-field mass-releases of wAlbB-infected Ae. aegypti males, as part of an Integrated Vector Management (IVM) plan led by the Mexican Ministry of Health, could suppress natural populations of Ae. aegypti in urbanized settings in south Mexico. METHODOLOGY/PRINCIPAL FINDINGS: We implemented a controlled before-and-after quasi-experimental study in two suburban localities of Yucatan (Mexico): San Pedro Chimay (SPC), which received IIT-SIT, and San Antonio Tahdzibichén used as control. Release of wAlbB Ae. aegypti males at SPC extended for 6 months (July-December 2019), covering the period of higher Ae. aegypti abundance. Entomological indicators included egg hatching rates and outdoor/indoor adult females collected at the release and control sites. Approximately 1,270,000 lab-produced wAlbB-infected Ae. aegypti males were released in the 50-ha treatment area (2,000 wAlbB Ae. aegypti males per hectare twice a week in two different release days, totaling 200,000 male mosquitoes per week). The efficacy of IIT-SIT in suppressing indoor female Ae. aegypti density (quantified from a generalized linear mixed model showing a statistically significant reduction in treatment versus control areas) was 90.9% a month after initiation of the suppression phase, 47.7% two months after (when number of released males was reduced in 50% to match local abundance), 61.4% four months after (when initial number of released males was re-established), 88.4% five months after and 89.4% at six months after the initiation of the suppression phase. A proportional, but lower, reduction in outdoor female Ae. aegypti was also quantified (range, 50.0-75.2% suppression). CONCLUSIONS/SIGNIFICANCE: Our study, the first open-field pilot implementation of Wolbachia IIT-SIT in Mexico and Latin-America, confirms that inundative male releases can significantly reduce natural populations of Ae. aegypti. More importantly, we present successful pilot results of the integration of Wolbachia IIT-SIT within a IVM plan implemented by Ministry of Health personnel.


Subject(s)
Aedes , Infertility, Male , Wolbachia , Animals , Female , Humans , Insecta , Male , Mexico , Mosquito Control/methods , Mosquito Vectors , Pilot Projects
12.
PLoS One ; 17(2): e0263836, 2022.
Article in English | MEDLINE | ID: mdl-35192647

ABSTRACT

BACKGROUND: Anopheles stephensi Listen (1901) is a major vector of malaria in Asia and has recently been found in some regions of Africa. The An. stepehnsi species complex is suspected to have three sibling species: type, intermediate, and mysorensis, each with its own vector competence to the malaria parasite and ecology. To identify the members of the species complex in our An. stephensi insectary colony, we used the morphological features of eggs and genetic markers such as AnsteObp1 (Anopheles stephensi odorant binding protein 1), mitochondrial oxidases subunit 1 and 2 (COI and COII), and nuclear internal transcribed spacer 2 locus (ITS2). METHODS: Eggs were collected from individual mosquitoes (n = 50) and counted for the number of ridges under stereomicroscope. Genomic DNA was extracted from female mosquitoes. After the amplification of partial fragments of AnsteObp1, COI, COII and ITS2 genes, the PCR products were purified and sequenced. Phylogenetic analysis was performed after aligning query sequences against the submitted sequences in GenBank using MEGA 7. RESULTS: The range of ridges number on each egg float was 12-13 that corresponds to the mysorensis form of An. stephensi. The generated COI, COII and ITS2 sequences showed 100%, 99.46% and 99.29% similarity with the sequences deposited for Chinese, Indian and Iranian strains of An. stephensi, respectively. All the generated AnsteObp1 intron I region sequences matched 100% with the sequences deposited for An. stephensi sibling species C (mysorensis form) from Iran and Afghanistan. CONCLUSIONS: This manuscript precisely describes the morphological and molecular details of the 'var mysorensis' form of An. stephensi that could be exploited in elucidating its classification as well as in differentiation from other biotypes of the same or other anopheline species. Based on our findings, we recommend AnsteObp1 as a robust genetic marker for rapid and accurate discrimination (taxonomic identification) of the An. stephensi species complex, rather than the COI, COII, and ITS2 marker, which could only be utilized for interspecies (Anopheles) differentiation.


Subject(s)
Anopheles/genetics , DNA Barcoding, Taxonomic/methods , Insect Proteins/genetics , Receptors, Odorant/genetics , Animals , Anopheles/classification , DNA Barcoding, Taxonomic/standards , Female , Genetic Markers , Introns , Reference Standards
13.
Front Microbiol ; 12: 671699, 2021.
Article in English | MEDLINE | ID: mdl-34305838

ABSTRACT

The sterile insect technique (SIT) has been developed as a component of area-wide integrated pest management approaches to control the populations of Aedes albopictus, a mosquito vector capable of transmission of dengue, Zika and chikungunya viruses. One of the key factors for the success of SIT is the requirement of high biological quality sterile males, which upon their release would be able to compete with wild males for matings with wild females in the field. In insects, gut bacteriome have played a catalytic role during evolution significantly affecting several aspects of their biology and ecology. Given the importance of gut-associated bacterial species for the overall ecological fitness and biological quality of their hosts, it is of interest to understand the effects of radiation on the gut-associated bacteriome of Ae. albopictus. In this study, the effect of radiation on the composition and density levels of the gut-associated bacterial species at the pupal stage as well as at 1- and 4-day-old males and females was studied using 16S rRNA gene-based next generation sequencing (NGS) and quantitative PCR (qPCR) approaches. Age, diet, sex, and radiation were shown to affect the gut-associated bacterial communities, with age having the highest impact triggering significant changes on bacterial diversity and clustering among pupae, 1- and 4-day-old adult samples. qPCR analysis revealed that the relative density levels of Aeromonas are higher in male samples compared to all other samples and that the irradiation triggers an increase in the density levels of both Aeromonas and Elizabethkingia in the mosquito gut at specific stages. Our results suggest that Aeromonas could potentially be used as probiotics to enhance protandry and sex separation in support of SIT applications against Ae. albopictus, while the functional role of Elizabethkingia in respect to oxidative stress and damage in irradiated mosquitoes needs further investigation.

14.
J Med Entomol ; 58(4): 1817-1825, 2021 07 16.
Article in English | MEDLINE | ID: mdl-33822117

ABSTRACT

We conducted a baseline characterization of the abundance and seasonality of Aedes aegypti (Linnaeus, 1762)-a vector of dengue, chikungunya, and Zika-in two suburban localities of Yucatan, Mexico, as the first step in the implementation of an integrated vector management (IVM) plan combining 'traditional Aedes control' (source reduction/truck-mounted ultra-low volume [ULV] spraying) and incompatible insect technique/sterile insect technique for population suppression in Yucatan, Mexico. Weekly entomological collections with ovitraps and BG-sentinel traps were performed in 1-ha quadrants of both localities for 1 yr. Three distinct periods/phases were identified, closely associated with precipitation: 1) a phase of low population abundance during the dry season (weekly average of Aedes eggs per ovitrap and adults per BG trap = 15.51 ± 0.71 and 10.07 ± 0.88, respectively); 2) a phase of population growth and greatest abundance of Aedes (49.03 ± 1.48 eggs and 25.69 ± 1.31 adults) during the rainy season; and finally 3) a phase of decline among populations (20.91 ± 0.97 eggs and 3.24 ± 0.21 adults) after the peak of the rainy season. Seasonal abundance and dynamics of Ae. aegypti populations suggest that it is feasible to develop and implement time-specific actions as part of an IVM approach incorporating integrating novel technologies (such as rear-and-release of Wolbachia-infected males) with classic (insecticide-based) approaches implemented routinely for vector control. In agreement with the local vector control program, we propose a pilot IVM strategy structured in a preparation phase, an attack phase with traditional vector control, and a suppression phase with inundative releases, which are described in this paper.


Subject(s)
Aedes , Infertility, Male/microbiology , Mosquito Control/methods , Wolbachia , Aedes/microbiology , Aedes/physiology , Animals , Arbovirus Infections/prevention & control , Arbovirus Infections/transmission , Male , Mexico/epidemiology , Mosquito Vectors/microbiology , Mosquito Vectors/physiology , Population Control/methods , Seasons
16.
J Insect Sci ; 20(5)2020 Sep 01.
Article in English | MEDLINE | ID: mdl-33034342

ABSTRACT

This study reports the results of a molecular screening for Wolbachia (Wb) infection in Aedes albopictus (Skuse) populations recently established in the Yucatan Peninsula, Mexico. To do so, collections of free-flying adults with BG traps and emerged adults from eggs after ovitrap field collections were performed in three suburban localities of the city of Merida, Yucatan. Overall, local populations of Ae. albopictus present a natural Wb infection rate of ~40% (18 of 45). Wb infection was detected in both field-collected adults (76.5%, 13 of 17) and eggs reared (17.8%, 5 of 28) and in 37.9% (11/29) of females and 43.7% (7/16) of male Ae. albopictus mosquitoes. An initial screening for Wolbachia strain typing showed that native Ae. albopictus were naturally coinfected with both wAlbA and wAlbB strains. The knowledge of the prevalence and diversity of Wolbachia strains in local populations of Aedes mosquitoes is part of the baseline information required for current and future Wolbachia-based vector control approaches to be conducted in Mexico.


Subject(s)
Aedes/microbiology , Wolbachia/isolation & purification , Animals , Mexico , Mosquito Vectors/microbiology , Pathology, Molecular
17.
Curr Biol ; 30(24): 4837-4845.e5, 2020 12 21.
Article in English | MEDLINE | ID: mdl-33035486

ABSTRACT

Progress has been made in developing the maternally inherited endosymbiotic bacterium Wolbachia as a tool for protecting humans from mosquito-borne diseases. In contrast, Wolbachia-based approaches have not yet been developed for the protection of plants from insect pests and their associated diseases, with a major challenge being the establishment of artificial Wolbachia infections expressing desired characteristics in the hemipterans that transmit the majority of plant viruses. Here, we report stable introduction of Wolbachia into the brown planthopper, Nilaparvata lugens, the most destructive rice pest that annually destroys millions of hectares of staple crops. The Wolbachia strain wStri from the small brown planthopper, Laodelphax striatellus, was transferred to this new host, where it showed high levels of cytoplasmic incompatibility, enabling rapid invasion of laboratory populations. Furthermore, wStri inhibited infection and transmission of Rice ragged stunt virus and mitigated virus-induced symptoms in rice plants, opening up the development of Wolbachia-based strategies against major agricultural pests and their transmitted pathogens. VIDEO ABSTRACT.


Subject(s)
Crop Protection/methods , Hemiptera/microbiology , Insect Vectors/microbiology , Oryza/virology , Wolbachia/pathogenicity , Animals , Feasibility Studies , Hemiptera/virology , Oryza/parasitology , Plant Diseases/prevention & control , Plant Diseases/virology , Reoviridae/pathogenicity
18.
PLoS Negl Trop Dis ; 14(9): e0008561, 2020 09.
Article in English | MEDLINE | ID: mdl-32881871

ABSTRACT

Combined incompatible and sterile insect technique (IIT-SIT) has been considered to be an effective and safe approach to control mosquito populations. Immobilization of male adults by chilling is a crucial process required for the packing, transportation and release of the mosquitoes during the implementation of IIT-SIT for mosquito control. In this study, effects of chilling on the Aedes albopictus males with triple Wolbachia infections (HC line), a powerful weapon to fight against the wild type Ae. albopictus population via IIT-SIT, were evaluated under both laboratory and field conditions. Irradiated HC (IHC) males were exposed to 1, 5 and 10°C for 1, 2, 3, 6 and 24 h. The survival rate of the post-chilled IHC males was then monitored. Longevity of post-chilled IHC males was compared to non-chilled males under laboratory and semi-field conditions. Mating competitiveness of IHC/HC males after exposure to 5 or 10°C for 0, 3 and 24 h was then evaluated. Effects of compaction and transportation under chilled conditions on the survival rate of IHC males were also monitored. The optimal chilling conditions for handling IHC males were temperatures between 5 and 10°C for a duration of less than 3 h with no negative impacts on survival rate, longevity and mating competitiveness when compared to non-chilled males. However, the overall quality of post-chilled IHC/HC males decreased when exposed to low temperatures for 24 h. Reduced survival was observed when IHC males were stored at 5°C under a compaction height of 8 cm. Transportation with chilling temperatures fluctuating from 8 to 12°C has no negative impact on the survival of IHC males. This study identified the optimal chilling temperature and duration for the handling and transportation of Ae. albopictus IHC male adults without any detrimental effect on their survival, longevity and mating competitiveness. Further studies are required to develop drone release systems specific for chilled mosquitoes to improve release efficiency, as well as to compare the population suppression efficiency between release of post-chilled and non-chilled males in the field.


Subject(s)
Aedes/microbiology , Aedes/physiology , Mosquito Control/methods , Wolbachia/physiology , Animals , Cold Temperature , Female , Male , Reproduction
19.
Food Sci Nutr ; 8(8): 4330-4339, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32884713

ABSTRACT

The purpose of this present study was to develop a rapid and effective approach for identification of red wines that differ in geographical origins, brands, and grape varieties, a multi-sensor fusion technology based on a novel cost-effective electronic nose (E-nose) and a voltammetric electronic tongue (E-tongue) was proposed. The E-nose sensors was created using porphyrins or metalloporphyrins, pH indicators and Nile red printed on a C2 reverse phase silica gel plate. The voltammetric E-Tongue with six metallic working electrodes, namely platinum, gold, palladium, tungsten, titanium, and silver was employed to sense the taste of red wines. Principal component analysis (PCA) was utilized for dimensionality reduction and decorrelation of the raw sensors datasets. The fusion models derived from extreme learning machine (ELM) were built with PCA scores of E-nose and tongue as the inputs. Results showed superior performance (100% recognition rate) using combination of odor and taste sensors than individual artificial systems. The results suggested that fusion of the novel cost-effective E-nose created and voltammetric E-tongue coupled with ELM has a powerful potential in rapid quality evaluation of red wine.

20.
Front Microbiol ; 11: 605, 2020.
Article in English | MEDLINE | ID: mdl-32351473

ABSTRACT

Insect symbionts are major manipulators of host's behavior. Their effect on parameters such as fecundity, male mating competitiveness, and biological quality in general, can have a major influence on the effectiveness of the sterile insect technique (SIT). SIT is currently being developed and applied against human disease vectors, including Ae. albopictus, as an environment-friendly method of population suppression, therefore there is a renewed interest on both the characterization of gut microbiota and their exploitation in artificial rearing. In the present study, bacterial communities of eggs, larvae, and adults (both males and females) of artificially reared Ae. albopictus, were characterized using both culture-dependent and culture-independent approaches. Mosquito-associated bacteria corresponding to thirteen and five bacteria genera were isolated from the larval food and the sugar solution (adult food), respectively. The symbiont community of the females was affected by the provision of a blood meal. Pseudomonas and Enterobacter were either introduced or enhanced with the blood meal, whereas Serratia were relatively stable during the adult stage of females. Maintenance of these taxa in female guts is probably related with blood digestion. Gut-associated microbiota of males and females were different, starting early after emergence and continuing in older stages. Our results indicate that eggs contained bacteria from more than fifteen genera including Bacillus, Chryseobacterium, and Escherichia-Shigella, which were also main components of gut microbiota of female adults before and after blood feeding, indicating potential transmission among generations. Our results provided a thorough study of the egg- and gut-associated bacteria of artificially reared Ae. albopictus, which can be important for further studies using probiotic bacteria to improve the effectiveness of mosquito artificial rearing and SIT applications.

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