Diversity Of Symbiotic Bacteria Research Articles

Diversity of symbiotic bacteria in the reproductive tracts and midgut of Culex pipiens

Background: Culex pipiens is considered a vector for the transmission of infectious, viral, and parasitic diseases. To control this mosquito vector, investigating symbiotic bacteria colonized inside the mosquitoes’ organs to impede the transmission of pathogens has been of recent interest to researchers. Methods: This revision was intended to provide a comprehensive overview of the diversity of endosymbiont bacteria residing in different tissues of Cx. pipiens globally by using reports in Google Scholar, PubMed, and Science Direct until May 2024. Result: The results showed that more than 50 bacterial genera have been reported in Culex tissues, in which the bacterial diversity was higher in the midgut than eggs or the whole body in Cx. pipiens. More than 65% of samples were insect-reared mosquitoes than wild types. Various methods based on culture-dependent and culture-independent approaches followed by molecular techniques such as 16SrRNA Illumina sequencing, Next Generation Sequencing (NGS), RNA shotgun metagenomic sequencing (RNA-seq), RTPCR, and MALDI-TOF MS have been used for the recognition of bacteria at genera or species levels. The most favorable gene for molecular analysis via PCR is 16SrRNA; however, the wsp gene was another candidate used for identification of the bacterial community. Conclusion: These results provide a library of defined bacteria associated with Cx. pipiens. The characterization of tissue-specific and host-specific bacterial communities sheds light on further studies pursuing the functional role of endosymbiont organisms in control strategies and vector biology.

Diversity of symbiotic bacteria in the digestive and circulatory systems of lobster and crayfish: important connections for efficient aquaculture. A systematic review

Abstract Lobsters and crayfishes have social, economic and ecological significance in several regions around the world. These crustaceans have complex digestive systems and open circulatory systems colonized by symbiotic microorganisms that play essential roles in the health, nutrition and disease of crustaceans, attracting considerable interest. The importance of the microbiota for the successful cultivation of animals in captivity is known, however, there is a lack of information about the symbiotic microbiota in different species of lobsters. The aim of this study was to summarize global information on microbiota studies of anatomical sites of lobsters and crayfishes looking for patterns of bacteria that colonize their intestine, hepatopancreas and haemolymph. A systematic review was conducted using “Methodi Ordinatio”. Twenty-five significant articles, from 12 countries, were identified for analysis from the Scopus database. The crustacean genera found were Cherax, Pacifastacus and Procambarus (crayfish); Homarus, Nephrops and Panulirus (lobsters). The intestinal, hepatopancreas and haemolymph microbiota show a wide variety of bacteria influenced by infections affecting the individual, stress caused by changes in the environment, availability and quality of food, period of the year, stage of development and the animal’s sex, among other aspects. The common core bacterial microbiota among crustaceans consist of the genera Acinetobacter, Aeromonas, Candidatus Bacilloplasma, Candidatus Hepatoplasma, Citrobacter, Hafnia, Photobacterium, Pseudomonas, Shewanella and Vibrio. The results broadened our understanding of the microbiota in the intestinal and circulatory systems of crustaceans, the flaws for and needs for standardization of analysis techniques, and the use of a multi-specialized approach for the protection and management of lobsters as a fisheries resource.

Evaluation of Transgenerational Effects of Sublethal Imidacloprid and Diversity of Symbiotic Bacteria on Acyrthosiphon gossypii

Symbiotic bacteria and hormesis in aphids are the driving forces for pesticide resistance. However, the mechanism remains unclear. In this study, the effects of imidacloprid on the population growth parameters and symbiotic bacterial communities of three successive generations of Acyrthosiphon gossypii were investigated. The bioassay results showed that imidacloprid had high toxicity to A. gossypii with an LC50 of 1.46 mg·L-1. The fecundity and longevity of the G0 generation of A. gossypii decreased when exposed to the LC15 of imidacloprid. The net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), and total reproductive rate (GRR) of G1 and G2 offspring were significantly increased, but those of the control and G3 offspring were not. In addition, sequencing data showed that the symbiotic bacteria of A. gossypii mainly belonged to Proteobacteria, with a relative abundance of 98.68%. The dominant genera of the symbiotic bacterial community were Buchnera and Arsenophonus. After treatment with the LC15 of imidacloprid, the diversity and species number of bacterial communities of A. gossypii decreased for G1-G3 and the abundance of Candidatus-Hamiltonella decreased, but Buchnera increased. These results provide insight into the resistance mechanism of insecticides and the stress adaptation between symbiotic bacteria and aphids.

Dynamics and diversity of symbiotic bacteria in Apolygus lucorum at different developmental stages

BackgroundApolygus lucorum is a worldwide omnivorous pest damaging a range of crops and causing great economic losses. Symbiotic bacteria living in insects play a key role in the nutrition, physiology, and behavior of hosts. Here, we present an experiment using Illumina HiSeq sequencing targeting the V3–V4 regions of bacteria’s 16S rRNA throughout the entire life cycle of A. lucorum.ResultsThe first and second instar nymphs have the largest alpha diversity compared with other life stages of the insect. Bacterial phyla Proteobacteria (72.29%), Firmicutes (15.24%), Actinobacteria (7.76%) exhibit the largest relative abundance in all developmental stages. Erwinia (23.97%) and Lactococcus (10.62%) are the two genera with the highest relative abundance. The relative abundance of Erwinia in the nymph stage is significantly greater than the adult stage, and the relative abundance of Lactococcus in 6-day-old and 9-day-old adult females is higher compared with adult males.ConclusionsThese results reveal that microbial community composition and relative abundance shift dynamically at different life stages, implying that different bacterial phyla and genera may have specific roles in specific life stages such as metabolism, nutrition absorption, detoxification, and reproduction. This study reveals for the first time the community composition and ecological dynamics of symbiotic bacteria throughout the life stages of A. lucorum, and thus may provide insight to new strategies for pest control.

The community profiles of symbiotic bacteria at the different life stages of coral Dipsastraea favus

Corals live in a symbiotic relationship with various bacteria that are fundamental to host fitness, health, and survival. Though the diversity of symbiotic bacteria has been revealed in the early life stages of some corals, the dynamic bacterial community profiles of one coral are still poorly characterized, particularly the stage-specific bacteria. In this study, the bacterial communities in the patent, eggs, and 4-day-old planula larvae of a hermaphrodite coral Dipsastraea favus were investigated by high-throughput sequencing of 16S ribosomal RNA gene. As a result, dynamic profiles of bacterial community in the parent, eggs and larvae of D. favus were suggested. The bacterial diversity in the planula larvae was a bit higher than that in the D. favus parent, and distinct stage-specific symbiotic bacteria were detected, e.g., Oceanospirillaceae, Kordia, and Legionellaceae in D. favus larvae, and Kiloniellales and Prosthecochloris in adult D. favus. The dynamic change of bacterial community in coral adults and larvae may expand our understanding of the complex relationship between coral host and its symbiotic microbiota.

Analysis of Intestinal Microbial Diversity of Four Species of Grasshoppers and Determination of Cellulose Digestibility.

Simple SummaryGrasshoppers are typical phytophagous pests, which prefer eating monocotyledons with more cellulose and hemicellulose. Due to its large appetite and high utilization rate, the intestinal contents of grasshoppers have the potential to be developed into a bioreactor, which can be applied to improve straw utilization efficiency in the future. The digestive tract of grasshoppers is a complex ecosystem, inhabited by a large number of microorganisms. The existence of these microorganisms enables grasshoppers to have high decomposition and utilization of plant fibers. However, there are few reports on the microflora structure and diversity of the digestive tract of grasshoppers. In this study, the diversity of symbiotic bacteria in the intestinal tract of four species of grasshoppers, namely Acrida cinerea, Trilophidia annulata, Atractomorpha sinensis and Sphingonotus mongolicus, was studied by using the method of constructing a 16S rRNA gene library and Illumina Miseq sequencing technology. At the same time, the digestibility of cellulose and hemicellulose of the four species of grasshoppers were determined and the relationship between digestibility and intestinal microbial diversity was analyzed. This study provided basic data for the development of the digestible bioreactor of cellulose and hemicellulose, which may provide a new idea for degrading straw.Grasshoppers (Insecta, Orthoptera, Acridoidea) are a large group of agricultural and animal husbandry pests. They have a large food intake with high utilization of plants fibers. However, the composition of the grasshopper gut microbial community, especially the relationship between gut microbial community and cellulose digestibility, remains unclear. In this research, 16S rRNA gene sequences were used to determine the intestinal microbial diversity of Acrida cinerea, Trilophidia annulata, Atractomorpha sinensis and Sphingonotus mongolicus, and Spearman correlation analysis was performed between the intestinal microbes of grasshoppers and the digestibility of cellulose and hemicellulose. The results showed that Proteobacteria was the dominant phylum and Klebsiella was the dominant genus in the guts of the four species of grasshoppers; there was no significant difference in the species composition of the gut microbes of the four species of grasshoppers. Spearman correlation analysis showed that Brevibacterium and Stenotrophomonas were significantly correlated with cellulose digestibility. Brevibacterium, Clavibacter, Microbacterium and Stenotrophomonas were significantly associated with hemicellulose digestibility. Our results confirmed that the gut microbes of grasshoppers were correlated with the digestibility of cellulose and hemicellulose, and indicated that grasshoppers may have the potential to develop into bioreactors, which can be applied to improve straw utilization efficiency in the future.

Facultative symbionts associated with aphid populations in citrus orchards in northern Tunisia

Like many insects, aphids (Hemiptera: Aphididae) can host a wide diversity of symbiotic bacteria that can be important drivers of their evolutionary ecology. In addition to the nutritional obligate symbiont Buchnera aphidicola, these phloem-sap feeding insects can host various facultative symbionts whose functional diversity depends on complex interactions with the host genotype and environmental factors. During sampling in citrus orchards in northern Tunisia, we collected aphids on citrus plants. The specimens belonged either to the cotton-melon aphid Aphis gossypii or the green citrus aphid Aphis spiraecola. We analysed the prevalence of Arsenophonus, Serratia symbiotica, Hamiltonella defensa and Regiella insecticola, four facultative symbionts frequently found in the genus Aphis and potentially associated with phenotypic effects related to nutrition, protection against parasites and tolerance of high temperatures. We found that the diversity and prevalence of facultative symbionts differed between these two aphid species that exploit similar ecological niches. In particular, we found a high prevalence of Arsenophonus in A. gossypii populations and that the defensive symbiont H. defensa was only present in A. spiraecola populations. These results are discussed in light of the ecology and life cycles of each of the species of aphid studied.