Variable organization of symbiont-containing tissue across planthoppers hosting different heritable endosymbionts.

Sap-feeding hemipteran insects live in associations with diverse heritable symbiotic microorganisms (bacteria and fungi) that provide essential nutrients deficient in their hosts' diets. These symbionts typically reside in highly specialized organs called bacteriomes (with bacterial symbionts) or mycetomes (with fungal symbionts). The organization of these organs varies between insect clades that are ancestrally associated with different microbes. As these symbioses evolve and additional microorganisms complement or replace the ancient associates, the organization of the symbiont-containing tissue becomes even more variable. Planthoppers (Hemiptera: Fulgoromorpha) are ancestrally associated with bacterial symbionts Sulcia and Vidania, but in many of the planthopper lineages, these symbionts are now accompanied or have been replaced by other heritable bacteria (e.g., Sodalis, Arsenophonus, Purcelliella) or fungi. We know the identity of many of these microbes, but the symbiont distribution within the host tissues and the bacteriome organization have not been systematically studied using modern microscopy techniques. Here, we combine light, fluorescence, and transmission electron microscopy with phylogenomic data to compare symbiont tissue distributions and the bacteriome organization across planthoppers representing 15 families. We identify and describe seven primary types of symbiont localization and seven types of the organization of the bacteriome. We show that Sulcia and Vidania, when present, usually occupy distinct bacteriomes distributed within the body cavity. The more recently acquired gammaproteobacterial and fungal symbionts generally occupy separate groups of cells organized into distinct bacteriomes or mycetomes, distinct from those with Sulcia and Vidania. They can also be localized in the cytoplasm of fat body cells. Alphaproteobacterial symbionts colonize a wider range of host body habitats: Asaia-like symbionts often colonize the host gut lumen, whereas Wolbachia and Rickettsia are usually scattered across insect tissues and cell types, including cells containing other symbionts, bacteriome sheath, fat body cells, gut epithelium, as well as hemolymph. However, there are exceptions, including Gammaproteobacteria that share bacteriome with Vidania, or Alphaproteobacteria that colonize Sulcia cells. We discuss how planthopper symbiont localization correlates with their acquisition and replacement patterns and the symbionts' likely functions. We also discuss the evolutionary consequences, constraints, and significance of these findings.

Oral and Fecal Microbiome in Molar-Incisor Pattern Periodontitis.

In order to improve our understanding on the microbial complexity associated with Grade C/molar-incisor pattern periodontitis (GC/MIP), we surveyed the oral and fecal microbiomes of GC/MIP and compared to non-affected individuals (Control). Seven Afro-descendants with GC/MIP and seven age/race/gender-matched controls were evaluated. Biofilms from supra/subgingival sites (OB) and feces were collected and submitted to 16S rRNA sequencing. Aggregatibacter actinomycetemcomitans (Aa) JP2 clone genotyping and salivary nitrite levels were determined. Supragingival biofilm of GC/MIP presented greater abundance of opportunistic bacteria. Selenomonas was increased in subgingival healthy sites of GC/MIP compared to Control. Synergistetes and Spirochaetae were more abundant whereas Actinobacteria was reduced in OB of GC/MIP compared to controls. Aa abundance was 50 times higher in periodontal sites with PD≥ 4 mm of GC/MIP than in controls. GC/MIP oral microbiome was characterized by a reduction in commensals such as Kingella, Granulicatella, Haemophilus, Bergeyella, and Streptococcus and enrichment in periodontopathogens, especially Aa and sulfate reducing Deltaproteobacteria. The oral microbiome of the Aa JP2-like+ patient was phylogenetically distant from other GC/MIP individuals. GC/MIP presented a higher abundance of sulfidogenic bacteria in the feces, such as Desulfovibrio fairfieldensis, Erysipelothrix tonsillarum, and Peptostreptococcus anaerobius than controls. These preliminary data show that the dysbiosis of the microbiome in Afro-descendants with GC/MIP was not restricted to affected sites, but was also observed in supragingival and subgingival healthy sites, as well as in the feces. The understanding on differences of the microbiome between healthy and GC/MIP patients will help in developing strategies to improve and monitor periodontal treatment.

Gut Dysbiosis in Chagas Disease. A Possible Link to the Pathogenesis.

Chagas disease is caused by the flagellate protozoan Trypanosoma cruzi. Cardiomyopathy and damage to gastrointestinal tissue are the main disease manifestations. There are data suggesting that the immune response to T. cruzi depends on the intestinal microbiota. We hypothesized that Chagas disease is associated with an altered gut microbiome and that these changes are related to the disease phenotype. The stool microbiome from 104 individuals, 73 with Chagas disease (30 with the cardiac, 11 with the digestive, and 32 with the indeterminate form), and 31 healthy controls was characterized using 16S rRNA amplification and sequencing. The QIIME (Quantitative Insights Into Microbial Ecology) platform was used to analyze the data. Alpha and beta diversity indexes did not indicate differences between the groups. However, the relative abundance of Verrucomicrobia, represented primarily by the genus Akkermansia, was significantly lower in the Chagas disease groups, especially the cardiac group, compared to the controls. Furthermore, differences in the relative abundances of Alistipes, Bilophila, and Dialister were observed between the groups. We conclude that T. cruzi infection results in changes in the gut microbiome that may play a role in the myocardial and intestinal inflammation seen in Chagas disease.

Biostimulation of metal-resistant microbial consortium to remove zinc from contaminated environments.

Understanding the diversity and metal removal ability of microorganisms associated to contaminated aquatic environments is essential to develop metal remediation technologies in engineered environments. This study investigates through 16S rRNA deep sequencing the composition of a biostimulated microbial consortium obtained from the polluted Tietê River in São Paulo, Brazil. The bacterial diversity of the biostimulated consortium obtained from the contaminated water and sediment was compared to the original sample. The results of the comparative sequencing analyses showed that the biostimulated consortium and the natural environment had γ-Proteobacteria, Firmicutes, and uncultured bacteria as the major classes of microorganisms. The consortium optimum zinc removal capacity, evaluated in batch experiments, was achieved at pH=5 with equilibrium contact time of 120min, and a higher Zn-biomass affinity (KF=1.81) than most pure cultures previously investigated. Analysis of the functional groups found in the consortium demonstrated that amine, carboxyl, hydroxyl, and phosphate groups present in the consortium cells were responsible for zinc uptake.