The mosquito microbiome comprises a diverse community of bacteria, fungi, and insect-specific viruses that reside within and may spread through various mosquito tissues (Pascar et al., 2023; Guégan et al., 2018). While the majority of these microorganisms are found within the gut, they are also found in other somatic and germline tissue such as the salivary gland, crop, reproductive tract and cuticle of Aedes mosquitoes (Onyango et al., 2021; Valiente Moro et al., 2013).

Mosquitoes can acquire their microbiota vertically from their parents. Various species of mosquitoes can vertically transmit intracellular bacteria, such as Wolbachia, from one generation to the next (Caragata et al., 2022). In contrast, several studies reported that microbiota are also acquired horizontally from the surrounding environment including aquatic habitat and feeding sources. Additionally, some microbial communities are transmitted via the egg surface (Coon et al., 2016). Upon hatching, first instar larvae ingest fragments of the eggshell, thereby acquiring microbes from the egg-associated microbiome (Gimonneau et al., 2014; Figure 2).

Bacteria represent the primary components of the mosquito gut microbiota, followed by fungi, algae, and viruses to a lesser extent (Guégan et al., 2018; Cansado-Utrilla et al., 2021). We identified twenty-five articles that focused on the bacterial composition of Aedes mosquito vectors. The articles included in this study used both culture-dependent and culture-independent methods. Two studies employed culture-dependent techniques, while the others utilized culture-independent approaches based on current molecular strategies such as 16S rRNA gene sequencing and metagenomic analysis, which have become essential tools for characterizing the bacterial microbiota in the mosquito gut.

Both culture dependent and culture independent studies confirmed that Aedes mosquitoes harbor a wide range of both classified and unclassified bacterial taxa associated with the gut (Bennett et al., 2019; Baltar et al., 2023). Among these, the most prevalent bacterial phyla identified in Aedes mosquitoes include Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes (Muturi et al., 2021a; Pascar et al., 2023).

Several studies conducted in the United States, consistently reported Proteobacteria as the dominant and highly diverse bacterial phylum in Aedes mosquitoes. Proteobacteria were a highly diverse and dominant phylum in both the midgut and saliva of Aedes mosquitoes (Pascar et al., 2023; Onyango et al., 2021). Similarly, Proteobacteria remained dominant phyla across the mosquito population regardless of variation in their aquatic habitats and blood meal sources (Caragata et al., 2022; Muturi et al., 2018).

The pattern was consistent with findings from India, where Proteobacteria as the dominant phylum in the gut of Ae. aegypti (Yadav et al., 2016; Sarma et al., 2022). Additional studies from diverse locations, including Brazil, Korea, and China, have corroborated the widespread dominance of Proteobacteria in the gut of Aedes mosquitoes (Akintola and Hwang, 2024; Baltar et al., 2023; Lee et al., 2020). This widespread dominance may result either from the insect host’s active recruitment of these bacteria that support its growth or from the greater ability of Proteobacteria to invade and proliferate within new insect hosts compared to other bacterial groups.

One of the most extensively studied genera within the Proteobacteria phylum is Wolbachia, a maternally inherited endosymbiont with critical implications for mosquito biology and vector competence. Studies have consistently reported Wolbachia as an abundant midgut bacterium in Aedes mosquito although the proportion and prevalence vary study and may depend on environmental, geographic, or methodological factors. A study from Spain and São Tomé found Wolbachia to be overwhelmingly dominant with 92.4–98. 8% in Sao Tome and 96.1–97.5% in Spanish samples, with 77.22% of mosquitoes co-infected with both wAlbA and wAlbB strains (Melo et al., 2024).

A similar study from Mexico, showed that Wolbachia accounted for 9.6% of 16S gene sequences, with the abundance 0 to 32% in each sample. A high prevalence of the wAlbB strain, and included genes linked to Cytoplasmic Incompatibility (CI) was detected (Hernández et al., 2024). Molecular approaches using Wolbachia specific primer and strain specific genetic marker essential for strain specific comparison and identification of genes related to CI.

Species and tissue specific occurrence of Wolbachia has been reported in different studies. A metagenomic analysis reported that the Prevalence of Wolbachia was 100% in Ae. albopictus and Cx. pipiens but not in other Aedes or Anopheles species. In addition to this Wolbachia was found to be more abundant in reproductive tissues where as Asaia was predominantly detected in the gut (Ilbeigi Khamseh Nejad et al., 2024). Similar study from Southern China reported that Wolbachia was more abundant in the whole body of Ae. albopictus than in the midgut. Additionally, microbiota network analysis revealed Wolbachia have both positive and negative co-occurrences with other bacterial genera (Lin et al., 2021). For example, Wolbachia and Asaia shows mutual exclusion in species and host tissue level (Rossi et al., 2015). This phenomenon has important implications for symbiont-based vector control strategies.

Studies from South Korea and Malaysia reported that Wolbachia was the most dominant genus, accounting for 98.36% of the midguts of Ae. albopictus with relative abundance in female and 70.5% of the bacterial community in the midgut of Ae. albopictus mosquitoes with relative abundance higher in male, respectively, (Lee et al., 2020; Ilbeigi Khamseh Nejad et al., 2024). Similar study from Brazil observed higher detection rates of Wolbachia in field-collected mosquitoes, particularly during the dry season (Baltar et al., 2023).

Likewise, a study in southern Thailand also reported Wolbachia prevalent in both sexes of Ae. albopictus, with greater abundance in males (Rodpai et al., 2023). Sex-based microbiota profiling, sample pooling, mosquito collection season, and geographical location might cause variation to abundance. Furthermore, due to methodological differences, Wolbachia is an intracellular bacterium that is not grown in artificial media and detected in culture-dependent studies (see Supplementary Table 1).

Another important bacterial genus in the Aedes gut microbiota is Enterobacter. The presence of Enterobacter was detected in the gut of adult Aedes mosquitoes collected from field but not in the egg or larval stages (Hernández et al., 2024). Contrastingly, study from Italy reported Enterobacter was detected in both Bacillus thuringiensis israelensis (Bti) exposed adults and larvae of Ae. albopictus, with a significantly higher abundance in Bti-resistant larvae (Bahrami et al., 2024). Similarly, study from Brazil reported a 3%, prevalence of Enterobacter isolated only from the eggs of Ae. aegypti mosquitoes that obtained from laboratory colony (Gusmão et al., 2010).

The variation in Enterobacter abundance across different developmental stages may be attributed to differences in sample sources and exposure to Bti larvicide, as Enterobacter has been previously associated with increased insecticide resistance. Meanwhile, a study from southern China reported that Enterobacter was present in both the entire body and midgut of both Aedes mosquitoes. In terms of abundance, it was more prevalent in the midgut of female Ae. albopictus than in its whole body (Lin et al., 2021). Additionally, a study from Thailand found that Enterobacter was present in all groups tested for CHIKV infection; however, its presence did not significantly correlate with infection status (Siriyasatien et al., 2024).

A study from the USA has shown that Enterobacter was the dominant genus among the five found in Ae. aegypti mosquitoes that fed on different blood meal sources (Muturi et al., 2021a). On the other hand, studies from India and Madagascar reported that Enterobacter was the second most dominant bacterium isolated in both sugar-fed female and male mosquitoes (Valiente Moro et al., 2013; Yadav et al., 2016). Furthermore, studies from Thailand and India reported that species like Enterobacter cloacae were particularly dominant in both Ae. aegypti and Ae. albopictus across field and lab populations (Yadav et al., 2015; Tuanudom et al., 2021). Enterobacter is symbiotic bacteria commonly detected in the gut of Aedes mosquito regardless of host species, method of isolation, and diet. This promotes microbial stability through beneficial co-occurrences in mosquito guts.

The genus Asaia, another member of the Proteobacteria, also plays a crucial role in the microbiota of Aedes. Studies from Iran detected Asaia in the midgut of field collected Ae. albopictus (Darbandsari et al., 2025). Roman et al. demonstrated that Asaia can accelerate the growth of Ae. aegypti larval development and interact with the broader larval microbiome (Roman et al., 2024). Interestingly, study from Thailand, found Asaia in CHIKV negative and control groups, but not found in infected mosquitoes (Siriyasatien et al., 2024). Similar study from the USA also reported variable Asaia spp. presence in Ae. aegypti populations with differing DENV susceptibility, although the role of Asaia spp. in antiviral defense remained unclear (Chen et al., 2023). The observed difference between infected, and uninfected groups mosquitoes can a possible association implying that Asaia may play a protective or modulatory role in vector competence. Further experimental infection studies are important to elucidate the association. Asaia was the most abundant genus in the Ae. aegypti sample that had been treated with a blood meal containing Amox/Clav and was reported as resistant to it (Van Garcia et al., 2024). It was found in Aedes, Anopheles, and Culex species, with varying prevalence depending on geographical location and mosquito species (Ilbeigi Khamseh Nejad et al., 2024). In Ae. aegypti Asaia was abundant in the crop than in the midgut (Villegas et al., 2023). Its abundance across has been reported at low and fluctuating levels across the regions such as Italy, Spain, and São Tomé (Ilbeigi Khamseh Nejad et al., 2024; Melo et al., 2024).

Other bacterial genera within Proteobacteria frequently detected in Aedes mosquitoes include Pseudomonas, Serratia, Pantoea, Klebsiella, and Aeromonas, as reported by multiple studies across the globe (Brettell et al., 2025; Darbandsari et al., 2025; Pascar et al., 2023; Muturi et al., 2021a; Rosso et al., 2018; Minard et al., 2015).

Firmicutes represent the second most abundant phylum in many studies. A study from the USA reported that Firmicutes accounted for 36.6% of Ae. aegypti microbiota, Bacillus and Clostridium were found in the midgut with Bacillus subtilis being the most dominant species at 42.4% (Pascar et al., 2023). Similar finding was reported in China Bacillus and Clostridium were present in both Bti-resistant and control larvae, with Bacillus being the predominant genus (Bahrami et al., 2024). Firmicutes were also the second most abundant phylum (27.2%) in whole-body microbiota of Ae. albopictus, with Bacillus dominating (22.9%). In contrast, tissue specific comparative analysis showed Bacteroidetes as the second most prevalent phylum, indicating variation in microbial composition across different tissues(Lin et al., 2021).

In contrast, Actinobacteria was the second most dominant phylum (11.3%), followed by Firmicutes (10.3%), Bacteroidetes (5%) and Cyanobacteria (1.3%) in Ae. aegypti. In this study Bacillus, Lysinibacillus, and Clostridium as common genera detected in adult (Hernández et al., 2024). Similarly high levels of Actinobacteria were detected in both laboratory-reared and field-collected Ae. albopictus (Tuanudom et al., 2021). Acinetobacter consisted of 17% of Ae. albopictus bacterial community, while Bacteroidetes was the least represented phylum, characterized by a single species, Chryseobacterium rhizoplanae, isolated from blood-fed individuals (Yadav et al., 2016).

Actinobacteria and Firmicutes were commonly found in larvae and breeding sites, however the mosquito gut appears more selective toward these bacterial groups. For example, Staphylococcus, Bacillus, and Clostridium are more likely associated with hindgut or body surface than midgut lumen (Ngo et al., 2016). Under laboratory condition larvae fed controlled larval diet, organic matter is limited, Firmicutes are less supported, whereas Actinobacteria tend to persist and adapt well to these stable, low-diversity microbiota environments.

Bacteroidetes were present in lower abundance in most studies, but its enrichment in mosquito gut associated with bloodmeal, Elizabethkingia with a dominant genera (Sharma et al., 2020). Variation in microbial abundance between species and across geographic regions has also been reported by Pascar et al. (2023). Bacteroidetes were 4.7 and 1.5% of Actinobacteria in Ae. aegypti mosquitoes. Actinobacteria and Bacteroidetes were present in Ae. albopictus mosquitoes in low abundance, but their abundance was high in Culex mosquitoes (Akintola and Hwang, 2024).

Similarly, Bacteroidetes were detected in both the midgut and saliva, bacteria belonging to the genus Elizabethkingia were enriched in ZIKV-infected midguts. In contrast, Wolbachia was abundant in non-infected midguts (Onyango et al., 2024). Elizabethkingia enrichment in infected mosquito midguts suggests a host-pathogen interaction, potentially involving an antiviral mechanism that influences viral replication. While Wolbachia prevalence in uninfected mosquitoes associates with mosquito immunity and suppressing arbovirus infection and replication.

In addition to the factors related to the abundance of certain bacteria in mosquito characterization of bacteria could biased by the techniques used for studying microbiota such as DNA extraction method, primer selection, sequencing platform and bioinformatics pipeline. Level of variability within the 16S rRNA genes also making it difficult to distinguish them in species or strain level. This might cause underestimation or over estimation of certain bacteria (see Supplementary Table 1).

A total of twenty-seven articles were retrieved that examined the various factors influencing the mosquito microbiome. Recent studies have shown that the microbial communities of Aedes mosquitoes vary significantly depending on several intrinsic and extrinsic factors, including mosquito species, developmental stage, sex, larval diet, and the environment of the breeding site.

For instance MacLeod et al. (2021) found that adult mosquitoes emerging from larvae reared on a nutrient-rich diet exhibited a significantly higher bacterial load in both their midguts and breeding water. Specifically, increased dietary abundance was associated with elevated levels of Enterobacteriaceae and Flavobacteriaceae and a decrease in Sphingomonadaceae. Larval nutrition not only affects growth and development but also influences microbial colonization. A significant increase in Enterobacteriaceae in larvae-fed pelleted diets however, Flavobacteriaceae levels remained essentially unchanged (Linenberg et al., 2016).

Martinson and Strand (2021) showed that larvae fed a complete bacterial community alongside nutrient-rich food exhibited distinct microbial profiles. Similarly, variation in midgut bacterial communities across developmental stages, sexes, and feeding conditions has been reported. For example, Acinetobacter pitti was abundant in sugar-fed females and larvae, while Pseudomonas monteilii dominated in blood-fed mosquitoes. Pantoea was prominent in adult males, whereas Chryseobacterium rhizoplanae, the only Bacteroidetes species isolated, was found exclusively in blood-fed Ae. albopictus (Yadav et al., 2016).

Environmental exposure during larval or adult stage also plays a significant role in diversity of microbiota. Scolari et al. found that over 60% of the bacterial genera was conserved in both larval and adult Ae. albopictus were also present in breeding site water (Scolari et al., 2021). Similarly, Alfano et al. (2019) reported that 84% of the bacterial communities in the mosquito gut were varied across breeding sites, larvae, pupae, and adults, with notable shifts in dominant taxa from the larval to adult stages.

Juma et al. (2021) observed that larval sampling environments significantly influenced microbial communities in Ae. triseriatus and Ae. japonicus, with Dysgonomonas being the dominant genus in Ae. triseriatus, while Mycobacterium and Carnobacterium were dominant in Ae. Japonicaus. Unclassified Comamonadaceae was dominant in water samples (Rodpai et al., 2023) confirmed that the composition of microbiota varies significantly across developmental stages and between Ae. aegypti and Ae. albopictus. While transstadial transmission of microbiota was observed, adult mosquitoes showed a reduced bacterial load compared to larvae. Microbiota also varies species to species, Wolbachia was more abundant in Ae. albopictus, whereas Blautia was enriched in Ae. aegypti.

Blood feeding has a profound effect on gut microbiota. Sarma et al. (2022) demonstrated a significant difference in the gut microbiota of Ae. aegypti depending on feeding status: Rhodobacterales and Neisseriales were enriched in mosquitoes fed with human blood, while Caulobacterales dominated in unfed mosquitoes. Supporting this finding, Muturi et al. (2021a) reported that the blood source influenced the composition of midgut microbiota. For example, newly emerged adults and those fed on chicken, rabbit, and human blood were characterized by Leucobacter, Chryseobacterium, Elizabethkingia, and Serratia, respectively, Whereas sugar-fed mosquitoes harbored more Pseudomonas.

Salgado et al. (2024) reported lower microbiota diversity in blood-fed mosquitoes compared to sugar-fed ones, with blood digestion dominated by Enterobacterales, followed by a rise in Elizabethkingia anopheles post-digestion. LaReau et al. (2023) highlighted taxonomic and functional differences between axenic mosquitoes colonized by environmental bacteria and those reared in insectaries. The former showed greater diversity and dynamic shifts during blood feeding and could even perform hemolysis in culture.

The composition and diversity of microbial communities in both larvae and adult mosquitoes are influenced by the colonization of microorganisms. Frankel-Bricker et al. (2020) demonstrated that the fungal colonization of the gut by Zancudomyces culisetae in larvae reduced microbial diversity in adults and affected the transmission of specific bacterial genera. Similarly, (Yin et al., 2025) demonstrated that inoculation with Escherichia coli, Staphylococcus aureus, and Beauveria bassiana altered the midgut microbiota across different stages.

Wei et al. (2017) reported that B. bassiana infection in mosquitoes induced gut dysbiosis, increasing bacterial load while reducing diversity. The gut became dominated by Acinetobacter, Serratia and Asaia, with Serratia marcescens overgrowth leading to translocation into the hemocoel and increased mortality. Wolbachia infection in Ae. aegypti also caused microbiome shifts and negatively interacted with other taxa (Pascar et al., 2023). Notably, Serratia was enriched in Wolbachia-infected mosquitoes, while Pseudomonas and Acinetobacter dominated in Wolbachia-free individuals (Balaji et al., 2021).

Viral infections also influence gut microbiota. DENV infection modulates bacterial abundance in Ae. aegypti, upregulating Desulfovibrionaceae and Enterococcus gallinarum while reducing overall bacterial load (Zhao et al., 2022). Similarly, (Ramirez et al., 2012) showed that DENV infection significantly decreases the overall bacterial load in the midgut of Ae. aegypti mosquito.

In addition to viral infections, chemical insecticides also significantly alter the microbiota of mosquitoes. Arévalo-Cortés et al. (2020) observed reduced gut diversity in both ZIKV-infected and lambda-cyhalothrin–resistant mosquitoes. Bacteroides vulgatus were enriched in ZIKV-infected groups, while Pseudomonas viridiflava and Clostridium ramosum were found in resistant mosquitoes. Additionally, Wei et al. (2023) demonstrated that pyrethroid exposure resulted in microbial enrichment or depletion, with genera such as Butyricimonas, Prevotellaceae, Anaerococcus, and Pseudorhodobacter significantly reduced.

Resistance mechanisms also drive microbiota shifts. Ae. aegypti resistant to permethrin showed different gut microbiota compared to susceptible strains (Muturi et al., 2021a). Viafara-Campo et al. (2025) found that deltamethrin-resistant females and temephos-treated larvae had distinct microbiota, with Enterobacter predominant in untreated females and resistant larvae, Bacillus exclusive to larvae, and Serratia, Cedecea neteri, and Elizabethkingia exclusive to resistant females. Sun et al. (2024b) similarly reported a higher abundance of certain gut symbiotic bacteria in deltamethrin field-resistant adults compared to sensitive adults; however, both field-resistant and field-sensitive adult mosquitoes exhibited significantly reduced gut microbiota diversity compared to laboratory-sensitive adults.

Antibiotic exposure also alters gut microbiota. A study by Qing et al. (2020) reported that ampicillin exposure in Ae.albopictus across developmental stages caused gut dysbiosis, particularly in adult females. Van Garcia et al. (2024) demonstrated that the ingestion of antibiotics during blood meals reduced microbial diversity, particularly in field-collected mosquitoes. Co-exposure with DENV-modified bacterial composition: Pseudomonas and Asaia decreased, while Enterobacter increased. Minard et al. (2015) also observed that larval antibiotic exposure led to a reduction in Elizabethkingia, elimination of Chryseobacterium and an increase in Wolbachia in adults.

Environmental pollutants, such as polycyclic aromatic hydrocarbons (PAHs), can also impact gut microbiota (Antonelli et al., 2024) reported stage-specific effects of chronic PAH exposure in Ae. albopictus with a greater impact on larvae. PAH exposure enriched bacterial families capable of PAH degradation, altering competitive dynamics in the gut. Moreover, CRISPR/Cas9 mediated deletion of bacteria ompA genes impaired colonization capability (Hegde et al., 2019).

Geographic distribution and environment also influence the composition of microbiota. Minard et al. (2015) found that mosquitoes invading new geographic areas had reduced microbial diversity compared to those from native regions. Brettell et al. (2025) showed that Ae. aegypti reared in different insectaries from eggs laid at the same time exhibited significantly different gut microbiota despite similar development.

Similarly, Ae.albopictus collected from Spain and São Tomé shared core microbiota but had location-specific genera, including different Wolbachia strains (Melo et al., 2024). Baltar et al. (2023) observed differences between lab colonies and field-collected mosquitoes, with gut microbiota diversity decreasing from wet to dry seasons (see Figure 3; Supplementary Table 2).

During blood feeding, mosquitoes might ingest pathogens, particularly Plasmodium parasites and/or arboviruses, which first enter the mosquito’s midgut. These pathogens penetrate the midgut epithelial cells, spread into the hemocoel, and ultimately cross the salivary gland barrier, gaining access to the saliva for transmission during subsequent bites (Mueller et al., 2010). Vector competence refers to the intrinsic ability of a mosquito to acquire, maintain, and transmit pathogens to another host. This is a complex biological trait influenced by various intrinsic and extrinsic factors, including the mosquito’s genetics and associated microbiota. The interaction between the mosquito genotype and its microbiota plays a crucial role in modulating vector competence (Cansado-Utrilla et al., 2021). Sixteen recent articles addressed the role of mosquito microbiota in pathogen transmission.

Studies have shown that the presence of a certain bacteria particularly a member of Rickettsiaceae, Enterobacteriaceae, and Flavobacteriaceae family can be corelated with reduced arboviral infection in mosquitoes(Kukutla et al., 2014; Apte-Deshpande et al., 2012; Moreira et al., 2009). The underlying mechanism by which the gut microbiome in aedes mosquito is not fully understood, but they are believed to involve both direct and indirect interactions.

Gut microbiota in mosquitoes can modify the gut environment by secreting antiviral metabolites and modulating the mosquito’s immune response, thereby inhibiting arbovirus entry, replication, and transmission. For example, Rosenbergiella YN46, found in field-collected Ae. albopictus has been shown to colonies the mosquito gut consistently. This bacterium secretes glucose dehydrogenase (RyGDH) enzyme, which changes glucose to gluconic acid during blood digestion. The accumulation gluconic acid in mosquito gut change the gut lumen to acidified environment which inactivate viruses and significantly inhibits invasion of DENV and ZIKV gut epithelial cells (Zhang et al., 2024) Similarly, Enterobacter hormaechei B17 (Eh_B17), a symbiotic gut bacterium, consistently colonizes the midgut of female mosquitoes after transplantation. Eh_B17 produces metabolite sphingosine, which significantly inhibits the early stages of DENV and ZIKV entry into host cells (Sun et al., 2024a).

Symbiotic bacteria can inhibit pathogen transmission by computing pathogen essential resources that are important for growth, replication and transmission. Wolbachia, an intracellular symbiotic bacterium, is widely used in mosquito control strategies and demonstrates antiviral properties. Transient somatic infections with Wolbachia strains wAlb and wMel significantly reduced Mayaro virus (MAYV) infection and viral titters in a strain-specific fashion. However, Wolbachia causes enhancement to Sindbis virus infection (Dodson et al., 2024). Wolbachia, alters cholesterol metabolism by diverting host resources from the mevalonate (MVA) pathway and downregulating cholesterol esterase genes, which are typically upregulated during ZIKV infection. This metabolic disruption depletes lipid droplets and inhibits ZIKV replication within mosquito cells (Edwards et al., 2023).

Wolbachia infection primarily blocks virus transmission, the mechanism is not fully explored yet, it could be activating the mosquito’s innate immune system or outcompeting with intracellular resource. Wolbachia strain NC-wMel, derived from crosses between Australian wMel females and New Caledonian wild-type males, and wMel-Sg from Singapore significantly reduced susceptibility to and blocked transmission of ZIKV, DENV, and CHIKV in Ae. aegypti. Notably, mosquitoes infected with NC-wMel exhibited complete CI and efficient maternal transmission (Pocquet et al., 2021; Tan et al., 2017). Similarly, populations of Wolbachia-infected Ae. aegypti (wMel), both in the field and in the laboratory, showed a significant reduction in DENV transmission potential and experienced an extended extrinsic incubation period of 4–7 days (Carrington et al., 2018).

Mosquito associated symbiotic bacteria also modify arboviral transmission by altering the expression or function of conserved mosquito proteins required for viral entry, replication and attachment. For example, Wolbachia (wAlbB) inhibits DENV-2 replication, Aag-2 Cells. wAlbB inhibited virus genome replication by blocking synthesis of the viral negative-strand RNA. In addition to this wAlbB inhibit DENV binding to Aag-2 cells by downregulating transcription of host membrane binding protein dystroglycan and beta-tubulin (Lu et al., 2020). Pelo protein is a conserved protein in insects involved in immune regulation, promoting Drosophila C virus replication in D. melanogaster (Wu et al., 2014). Wolbachia-infected Ae. aegypti females (wMelPop-CLA), showed reduced expression of Pelo and altered subcellular localization, which could potentially contribute to decreased DENV replication (Asad et al., 2018).

Symbiotic bacteria in the mosquito gut can produce natural toxins, antiviral compounds, or metabolites that prevent viruses from attaching to the gut lining and promote the degradation of viral genomes before attachment. The previous ingestion of Chromobacterium sp. Panama (Csp_P) by mosquitoes significantly reduced susceptibility to P. falciparum and DENV infection, both in vitro and in vivo (Ramirez et al., 2014). In support of this, Csp_Panama exhibits an inhibitory effect on DENV replication both in mosquitoes and in-vitro. Neutral protease and amino-peptidase enzymes destabilize the virus by degrading the viral envelope protein. This degradation of the viral envelope protein inhibits viral attachment to the host cell (Saraiva et al., 2018).

Likewise, Chromobacterium sp. Beijing (Csp_BJ), isolated from Ae. aegypti produces two antiviral effectors, CbAE-1 and CbAE-2, with conserved lipase domains. These lipases disrupt viral envelopes, thereby inactivating DENV, Japanese encephalitis virus (JEV), YFV, and ZIKV. Furthermore, high doses of Csp_BJ administered orally result in significant mortality in mosquitoes (Yu et al., 2022). Prostaglandins (PGs), immune-active lipids, are produced by midgut tissues in response to microbiota and play crucial roles in mosquito immunity. Enterobacter cloacae triggers PG production in the midgut of Ae. aegypti and in Aag2 cells, which in turn enhance antiviral immune responses against DENV (Barletta et al., 2020).

Introduction of symbiotic bacteria isolated from mosquito guts of antibiotic-treated mosquito shows a significant role in modulating viral replication.,by boosting mosquitoes innate immune system, particularly the upregulation of AMPs, and upregulation of immune pathway leading to reduced viral infection and viral titters. Furthermore, microbial competition between symbiont and viruses in the gut creates a hostile environment for viral replication. Proteus sp. and Paenibacillus sp. were introduced through blood meals and significantly reduced DENV infection and viral titters in aseptic mosquitoes. Notably, sugar meal supplementation with Proteus spp. also decreased DENV infection rates (Ramirez et al., 2012).

Similarly, Elizabethkingia anopheles aegypti colonize Ae, albopictus resulted in lower average ZIKV infections and reduced viral loads in Vero cell assays for ZIKV, DENV, or CHIKV (Onyango et al., 2021). Lysinibacillus spp., previously recognized for its larvicidal activity, was recently shown to reduce ZIKV viral loads in the head and thorax of Ae. aegypti, with no detectable virus in the saliva following forced feeding (Do Nascimento et al., 2022; see Table 1).

Eight articles addressed the use of mosquito microbiota in strategies for vector control. Applications of microbial-based approaches suppress the Aedes mosquito population. For example, an independent evaluation of Wolbachia-infected male (WIM) mosquito releases in Harris county, Texas, showed that CI induced by Wolbachia significantly reduced Ae. aegypti populations by over 90%. Similarly, large-scale field releases of Ae. aegypti mosquitoes infected with the wMel strain of Wolbachia have led to the stable establishment of the bacterium in local mosquito populations, with a consistent prevalence of over 60% (Lozano et al., 2022).

Similarly, large-scale field releases of Ae. aegypti mosquitoes infected with the wMel strain have led to the stable establishment of the bacterium in local mosquito populations, with a consistent prevalence of over 60%. Due to the large-scale establishment of Wolbachia, the incidence of dengue has been reduced (Velez et al., 2023), resulting in a 38% decrease in dengue cases and a 10% reduction in chikungunya cases (Ribeiro Dos Santos et al., 2022).

Other studies have also reported that introgression, which involves crosses between wild Wolbachia-infected Ae. albopictus males (carrying the wild wPip strain) and naturally infected wAlbA/B females lead to complete bidirectional CI, as shown by 0% egg hatch rates. The life history traits in these wild-wPip crosses were similar to those observed in laboratory crosses between lab-wPip males and wild wAlbA/B females (Lejarre et al., 2025). Similarly, the presence of Wolbachia strain wMelM in female Ae. aegypti triggers fitness costs that disrupt egg retention and prevent oviposition (Ross et al., 2025). Introgression of the genetic background from a wild population into a Wolbachia-infected line capable of producing incompatible males (Cholvi et al., 2024).

A pilot study conducted in southern Mexico tested the integration of the Sterile Insect Technique (SIT) and the Incompatible Insect Technique (IIT) using wAlbB-infected Ae. aegypti males. These mosquitoes were mass-reared, irradiated for sterilization, and released in urban areas. After release rates resumed at the five-month mark, the intervention led to an 88.4–89.4% reduction in indoor Ae. aegypti presence and an overall population suppression rate ranging from 50 to 75.2% (Martín-Park et al., 2022). Similarly, combined use of IIT and SIT through the mass release of male Ae. albopictus mosquitoes resulted in a 62% decrease in larval abundance and a 65% decrease in adult populations over the course of a year (Zheng et al., 2019).

Wolbachia-based vector control has shown great promise in reducing arbovirus transmission and mosquito populations. Field releases in endemic areas have significantly decreased disease incidence. However, large-scale, sustainable implementation requires coordinated multidisciplinary collaboration, standardized methodologies, and long-term ecological monitoring to adapt to variable field conditions and maintain success (O’Neill et al., 2019; Nazni et al., 2019).

Beyond Wolbachia-based interventions, some resident bacteria in mosquito influence the physiology of mosquito species; cause mortality, induce the sterility and extent mosquito development. Chromobacterium sp. (Csp_P), Chromobacterium sp. Panama (Csp_P), isolated from field-derived Ae. aegypti showed strong entomopathogenic effects. Larval exposure to Csp_P in breeding water and adult consumption of the bacterium resulted in high mosquito mortality (Ramirez et al., 2014).

A recent study on bacteria and their metabolites isolated from Aedes mosquitoes demonstrated significant larvicidal activity against Ae. aegypti larvae. Among the most promising genera were Bacillus spp., Enterobacter spp. and Stenotrophomonas spp. (De Oliveira et al., 2024). Rajagopal and Ilango (2021) studied the effect of Exiguobacterium spp. (specifically E. aestuarii and E. profundum) on Ae. aegypti larvae. Exposure to different bacterial concentrations significantly prolonged larval development (from 11.41 to 14.78 days) and resulted in reduced fecundity and egg hatchability. Similarly, the Rahnella aquatilis isolate RAeA1, found throughout the tissues of Ae. albopictus was shown to impair female reproductive physiology. Inoculating adult mosquitoes with RAeA1 resulted in disrupted egg production and ovarian development due to reduced levels of ecdysteroids and vitellogenin hormones, which are essential for successful reproduction (Gu et al., 2025).

The gut microbiota of Aedes mosquitoes has been explored for its potential to control arbovirus through Para-transgenesis, which involves the genetic engineering of symbiotic microorganisms to express antipathogen effector molecules. Symbiotic bacterium Serratia AS1 has been genetically engineered to express effector molecules targeting pathogens. Mosquitoes harboring engineered Serratia demonstrated significant inhibition of Plasmodium and ZIKV infections in both Anopheles and Aedes mosquitoes (Hu et al., 2025; Table 2).