Microbiota: A Consequential Third Wheel in the Mosquito-Pathogen Relationship

Editorial

18 January 2022

Editorial: Microbiota: A Consequential Third Wheel in the Mosquito-Pathogen Relationship

Mathilde Gendrin

Guido Favia

and

Jeremy K. Herren

2,147 views

0 citations

Editors

Mathilde Gendrin

Institut Pasteur de la Guyane

Guido Favia

University of Camerino

Jeremy Keith Herren

International Centre of Insect Physiology and Ecology (ICIPE)

Impact

Fluorescence microscopy of Microsporidia MB in An. arabiensis male ejaculatory ducts. (A) Schematic diagram of the male Anopheles gonad shows the position of the ejaculatory duct in relation to seminal vesicle, male accessory gland and testes. (B) Fluorescence microscopy images indicate that Microsporidia MB meronts (a) are found in the male An. arabiensis ejaculatory duct. Multinucleate Microsporidia MB cells can be observed containing 4 and 8 distinct nuclei (b,c), which likely corresponds to the progression on of 4-nuclei sporogonial plasmodia into the 8-nuclei sporogonial plasmodia and ultimately into sporophorous vesicles. Scale bar = 50 μm.

Original Research

28 July 2021

Horizontal Transmission of the Symbiont Microsporidia MB in Anopheles arabiensis

Godfrey Nattoh

, 14 more and

Jeremy K. Herren

The recently discovered Anopheles symbiont, Microsporidia MB, has a strong malaria transmission-blocking phenotype in Anopheles arabiensis, the predominant Anopheles gambiae species complex member in many active transmission areas in eastern Africa. The ability of Microsporidia MB to block Plasmodium transmission together with vertical transmission and avirulence makes it a candidate for the development of a symbiont-based malaria transmission blocking strategy. We investigate the characteristics and efficiencies of Microsporidia MB transmission between An. arabiensis mosquitoes. We show that Microsporidia MB is not transmitted between larvae but is effectively transmitted horizontally between adult mosquitoes. Notably, Microsporidia MB was only found to be transmitted between male and female An. arabiensis, suggesting sexual horizontal transmission. In addition, Microsporidia MB cells were observed infecting the An. arabiensis ejaculatory duct. Female An. arabiensis that acquire Microsporidia MB horizontally are able to transmit the symbiont vertically to their offspring. We also investigate the possibility that Microsporidia MB can infect alternate hosts that live in the same habitats as their An. arabiensis hosts, but find no other non-anopheline hosts. Notably, Microsporidia MB infections were found in another primary malaria African vector, Anopheles funestus s.s. The finding that Microsporidia MB can be transmitted horizontally is relevant for the development of dissemination strategies to control malaria that are based on the targeted release of Microsporidia MB infected Anopheles mosquitoes.

9,691 views

26 citations

Original Research

07 July 2021

The Effect of Secondary Metabolites Produced by Serratia marcescens on Aedes aegypti and Its Microbiota

Katy Heu

, 7 more and

Mathilde Gendrin

4,865 views

21 citations

Abundance of Cedecea is significantly affected by larval diet amount in all sample types. Abundance of one OTU that mapped to the genus Cedecea was significantly affected by larval diet amount (W = 58, significant at 0.8 cutoff threshold). Abundance is plotted for all sample types, diet treatments, and biological replicates. Abundance is lowest in R1 in general and higher in R2 and R4 treatments. This is consistent across all sample types and replicates with the singular exception of the first replicate of adult blood fed samples.

Original Research

18 June 2021

Larval Diet Abundance Influences Size and Composition of the Midgut Microbiota of Aedes aegypti Mosquitoes

Hannah J. MacLeod

, 1 more and

Sarah M. Short

4,577 views

30 citations

Performance metrics of A. aegypti reared on diet combinations of lactalbumin, torula yeast, and natural detritus. For each diet composition, mosquitoes were reared with three microbiotas: ALL7, Acinetobacter (A), and Rahnella (R). Bars indicate mean abundance for the treatment. The “X” marks at the bottom of data columns for “Time to Pupa” and “Wing Length” indicate that larvae did not develop into pupae or adults, respectively. Positive control mosquitoes were reared on RCM diet with the ALL7 microbiota. 1×, diet provisioned at 1/3 quantity of RCM diet; 2×, diet provisioned at 2/3 quantity of RCM diet; –, omitted from diet. The number of adult male and female mosquitoes is listed at the bottom for each treatment.

Original Research

08 June 2021

Diet–Microbiota Interactions Alter Mosquito Development

Vincent G. Martinson

and

Michael R. Strand

5,231 views

27 citations

Original Research

30 April 2021

Trained Immunity in Anopheles gambiae: Antibacterial Immunity Is Enhanced by Priming via Sugar Meal Supplemented With a Single Gut Symbiotic Bacterial Strain

Aditi Kulkarni

, 6 more and

Jiannong Xu

4,619 views

18 citations

Original Research

12 May 2021

Comprehensive Ecological and Geographic Characterization of Eukaryotic and Prokaryotic Microbiomes in African Anopheles

Eugeni Belda Cuesta

, 13 more and

Michelle M. Riehle

4,003 views

8 citations

Review

06 April 2021

Mosquito Trilogy: Microbiota, Immunity and Pathogens, and Their Implications for the Control of Disease Transmission

Paolo Gabrieli

, 5 more and

Sara Epis

In mosquitoes, the interaction between the gut microbiota, the immune system, and the pathogens that these insects transmit to humans and animals is regarded as a key component toward the development of control strategies, aimed at reducing the burden of severe diseases, such as malaria and dengue fever. Indeed, different microorganisms from the mosquito microbiota have been investigated for their ability to affect important traits of the biology of the host insect, related with its survival, development and reproduction. Furthermore, some microorganisms have been shown to modulate the immune response of mosquito females, significantly shaping their vector competence. Here, we will review current knowledge in this field, focusing on i) the complex interaction between the intestinal microbiota and mosquito females defenses, both in the gut and at humoral level; ii) how knowledge on these issues contributes to the development of novel and targeted strategies for the control of mosquito-borne diseases such as the use of paratransgenesis or taking advantage of the relationship between Wolbachia and mosquito hosts. We conclude by providing a brief overview of available knowledge on microbiota-immune system interplay in major insect vectors.

13,330 views

71 citations

Original Research

17 February 2021

Identification of a Novel Brevibacillus laterosporus Strain With Insecticidal Activity Against Aedes albopictus Larvae

Giulia Barbieri

, 12 more and

Alessandra M. Albertini

5,754 views

13 citations

Original Research

28 January 2021

Exploring Changes in the Microbiota of Aedes albopictus: Comparison Among Breeding Site Water, Larvae, and Adults

Francesca Scolari

, 4 more and

Mariangela Bonizzoni

Non-metric multidimensional scaling (NMDS) of water, larval and adult samples. Colors in the bidimensional NMDS plot are used according to the different sample origin as shown in the legend. Start and End refers to water collected at the moment of mosquito collection and after all adults had emerged, respectively. FO and CR refer to mosquitoes of the Foshan laboratory strain or collected in the wild, respectively.

The mosquito body hosts highly diverse microbes, which influence different physiological traits of both larvae and adults. The composition of adult mosquito microbiota is tightly linked to that of larvae, which are aquatic and feed on organic detritus, algae and prokaryotic microorganisms present in their breeding sites. Unraveling the ecological features of larval habitats that shape the structure of bacterial communities and their interactions with the mosquito host is still a poorly investigated topic in the Asian tiger mosquito Aedes albopictus, a highly invasive species that is vector of numerous arboviruses, including Dengue, Chikungunya, and Zika viruses. In this study, we investigated the composition of the bacterial community present in the water from a natural larval breeding site in which we separately reared wild-collected larvae and hatched eggs of the Foshan reference laboratory strain. Using sequence analysis of bacterial 16S rRNA gene amplicons, we comparatively analyzed the microbiota of the larvae and that of adult mosquitoes, deriving information about the relative impact of the breeding site water on shaping mosquito microbiota. We observed a higher bacterial diversity in breeding site water than in larvae or adults, irrespective of the origin of the sample. Moreover, larvae displayed a significantly different and most diversified microbial community than newly emerged adults, which appeared to be dominated by Proteobacteria. The microbiota of breeding site water significantly increased its diversity over time, suggesting the presence of a dynamic interaction among bacterial communities, breeding sites and mosquito hosts. The analysis of Wolbachia prevalence in adults from Foshan and five additional strains with different geographic origins confirmed the described pattern of dual wAlbA and wAlbB strain infection. However, differences in Wolbachia prevalence were detected, with one strain from La Reunion Island showing up to 18% uninfected individuals. These findings contribute in further understanding the dynamic interactions between the ecology of larval habitats and the structure of host microbiota, as well as providing additional information relative to the patterns of Wolbachia infection.

7,484 views

36 citations