Search

Objective: To identify the mosquito species collected in the field of 8 cities/counties of Hainan province, China and to analyze the characteristics of genetic differentiation of the predominant mosquito species. The types, contents and composition characteristics of the midgut microbiota of various mosquito species were explored to provide evidence for the control and prevention of mosquito-borne diseases in Hainan province. Methods: Adult mosquitoes were collected in the field using light traps, human lure or cattle lure methods. Morphology and DNA-barcoding technology (COI gene) were applied to identify the mosquito species. The V3-V4 hypervariable region of microbes 16S rRNA was used for high-throughput sequencing of the midgut microbiota, and SPSS 21.0 and R v3.1.1 software were employed to perform statistical analysis of the sequencing results and the Beta diversity analysis. Results: Aedes (Ae.) albopictus, Armigeres (Ar.) subalbatus and Culex (Cx.) pipiens pallpens were the three predominant species of the mosquito samples. Ae. albopictus was closely related to MK736660 (India) and JQ235749 (Yunnan), while MT541282 (DF, Dongfang) was a relatively independent population. The composition and structure of bacterial communities significantly varied among most of the samples (P

Eocanthecona furcellata is an important predatory stinkbug that attacks many lepidopteran pests. For mass-rearing, artificial diets are used to rear this predator in the laboratory; however, the fitness of the predators is reduced, and little is known about the cause. Since gut microbiota plays vital roles in the digestion and development of many hosts and can consequently affect host fitness, an understanding of the microbial community composition of E. furcellata may help to solve this unresolved problem. We compared the development and reproduction of E. furcellata reared on an artificial diet, and a natural (Spodoptera litura) or semi-natural (Tenebrio molitor) diet, and then the midgut microbiota were assessed using high-throughput 16S rRNA. The results of the high-throughput 16S rRNA show that the bacterial richness and diversity in the artificial diet gut samples increased considerably compared with the other samples. Proteobacteria and Firmicutes were the dominant phyla in E. furcellata. At the genus level, Serratia (however, the relative abundance was lower in the artificial diet gut samples), Enterococcus, and an uncultured bacterium genus of family Enterobacteriaceae, were dominant. The midgut microbiota components significantly differed among the diets, indicating that the gut bacteria had a dietary association with E. furcellata. This study provides a better understanding of midgut microbiota and the artificial diets that might affect them in E. furcellata.

Abstract Background The gut microbiota is known to play a role in a mosquito vector’s life history, a subject of increasing research. Laboratory experiments are essential for such studies and require laboratory colonies. In this study, the conservation of field-obtained midgut microbiota was evaluated in laboratory-reared Anopheles gambiae (s.l.) mosquitoes continuously hatched in water from field breeding habitats. Methods Pupae and late instars were obtained from the field and reared, and the emerged adults were blood-fed. The eggs obtained from them were hatched in either water from the field or in dechlorinated tap water. The mosquito colonies were maintained for 10 generations. Midguts of female adults from unfed F0 (emerging from field-caught pupae and larvae), F5 and F10 were dissected out and genomic DNA was extracted for 16S metagenomic sequencing. The sequences were compared to investigate the diversity and bacterial compositional differences using ANCOM and correlation clustering methods. Results Less than 10% of the bacterial families identified had differential relative abundances between generational groups and accounted for 46% of the variation observed. Although diversity reduced in F10 mosquitoes during laboratory colonization (Shannon-Weaver; P-value < 0.05), 50% of bacterial genera were conserved in those bred continuously in field-water compared to 38% in those bred in dechlorinated tap water. Conclusions To our knowledge, this study is the first report on the assessment of gut bacterial community of mosquitoes during laboratory colonization and recommends the use of water from the natural breeding habitats if they are intended for microbiota research.

Abstract Background Microbiota inhabiting midguts of mosquitoes play a key role in the host - parasite interaction and enhance vectorial capacity of viral diseases like dengue and chikungunya fevers. Mosquito midgut is considered to be an important site for host-pathogen interaction and pathogen survival is thought to be an outcome of this interaction. In the present study we examined the bacterial community in the midgut of Aedes mosquitoes in Arunanchal Pradesh, India, a subtropical zone where dengue fever is reported to be emerging. Method Larvae and pupa of Aedes mosquitoes were collected from a biodiversity hotspot, Bhalukpong, Arunachal Pradesh, India. 16S rRNA gene sequences were used for identification of isolated bacterial population from each species of mosquitoes. We used various diversity indices to assess the diversity and richness of the bacterial isolates in both mosquito species. Result On the basis of 16S rRNA gene sequence analysis a total of 24 bacterial species from 13 genera were identified belonging to 10 families of four major phyla. Phylum Proteobacteria was dominant followed by Firmicutes, Bacteroidetes and Actinobacteria. The midgut bacteria belonging to the phylum Proteobacteria and Firmicutes were isolated from both Ae. albopictus and Ae. aegypti, whereas, bacteria belonging to phylum Bacteroidetes and Actinobacteria were isolated only from Ae. albopictus and Ae. aegypti respectively. Enterobacter cloacae was the dominant bacterial species in both Ae. albopictus (33.65 %) and Ae. aegypti (56.45 %). Bacillus aryabhattai (22.78 %) was the second most common bacterial species in Ae. albopictus whereas, in Ae. aegypti the second most common bacterial species was Stenotrophomonas maltophilia (7.44 %). Conclusion The family Enterobacteriaceae of phylum Proteobacteria was dominant in both species of Aedes mosquitoes. To the best of our knowledge, this is the first attempt to study midgut microbiota from a biodiversity hotspot in Northeastern India. Some bacterial genera Enterobacter and Acinetobacter isolated in this study are known to play important roles in parasite-vector interaction. Information on midgut microflora may lead towards the development of novel, safe, and effective strategies to manipulate the vectorial capacity of mosquitoes.

Abstract Background Due to the effect of midgut bacteria on proliferation of parasites and their potential as paratransgenesis tools, their identification in malaria vector mosquitoes is important. Anopheles culicifacies s.l. is one of the main malaria vectors in Asia; however, its midgut microbiota remains un-studied. This work was primarily designed to isolate potential candidates for use in a paratransgenesis approach, but also to give a picture of the midgut microbiota of wild-caught An. culicifacies larvae and adults from the southeast corner of Iran, which has the highest malaria endemicity in the country. Methods A total of 68 larvae and 34 adult females (newly eclosed and older) from three different biotopes in Iran were analyzed for their midgut microflora. The mosquitoes had their midgut bacterial contents plated on three different culture media (brain heart agar, nutrient agar and blood agar) yielding 57 bacterial isolates. The 16S rRNA genes of the isolates were sequence analyzed for species designation, which then was confirmed by biochemical analysis. Results A total of twelve bacterial genera were identified: Acinetobacter, Aeromonas, Bacillus, Chryseobacterium, Delftia, Exiguobacterium, Kurthia, Microbacterium, Pseudomonas, Staphylococcus, Thorsellia and Variovorax. In older females, only Gram-negative bacteria were found, whereas larvae and newly-eclosed adults also harbored Gram-positive bacteria. The diversity of isolates also varied between sampling sites and mosquito stages, with the largest number of genera found in the Anguri district and in larvae, respectively. Pseudomonas was the most common genus retrieved from all sampling sites, and in both larvae and adults, suggesting a potential transstadial passage of these bacteria. Interestingly, identical 16S sequences of Pseudomonas were found in mosquitoes originating from different habitats at least 45 km apart, which could suggest that these bacteria have been adapted to the mosquitoes. Conclusions The study of vector mosquito microbiota has recently gathered increased interest because of the potential influence on vector competence. By adding data from a hitherto uncharacterized malaria mosquito, a better picture of gut flora in vector mosquitoes was obtained. Furthermore, some species of the predominant genus Pseudomonas will be evaluated for the selection of a paratransgenesis candidate.