Intestinal Tract Of Termites Research Articles

A new family for 'termite gut treponemes': description of Breznakiellaceae fam. nov., Gracilinema caldarium gen. nov., comb. nov., Leadbettera azotonutricia gen. nov., comb. nov., Helmutkoenigia isoptericolens gen. nov., comb. nov., and Zuelzera stenostrepta gen. nov., comb. nov., and proposal of Rectinemataceae fam. nov.

The intestinal tracts of termites are abundantly colonized by a diverse assemblage of spirochetes. Most of them belong to 'termite cluster I', a monophyletic group within the radiation of the genus Treponema that occurs exclusively in termite guts. Phylogenomic analysis revealed that members of the genus Treponema are extremely diverse and represent two separate, family-level lineages: the Treponemataceae sensu stricto, which comprise the majority of the validly described Treponema species, and a second lineage that comprises the remaining members of the genus Treponema, including all members of 'termite cluster I' from termites and the recently isolated Breznakiella homolactica from cockroaches. Here, we present the formal description of Breznakiellaceae fam. nov. and of the new genera required to accommodate the misplaced Treponema species in the new family as new combinations (Leadbettera azotonutricia, Gracilinema caldarium, Helmutkoenigia isoptericolens and Zuelzera stenostrepta). To avoid paraphyly of Treponemataceae, we propose Rectinemataceae fam. nov. to include the genus Rectinema.

'Candidatus Adiutrix intracellularis', an endosymbiont of termite gut flagellates, is the first representative of a deep-branching clade of Deltaproteobacteria and a putative homoacetogen.

Termite gut flagellates are typically colonized by specific bacterial symbionts. Here we describe the phylogeny, ultrastructure and subcellular location of 'Candidatus Adiutrix intracellularis', an intracellular symbiont of Trichonympha collaris in the termite Zootermopsis nevadensis. It represents a novel, deep-branching clade of uncultured Deltaproteobacteria widely distributed in intestinal tracts of termites and cockroaches. Fluorescence in situ hybridization and transmission electron microscopy localized the endosymbiont near hydrogenosomes in the posterior part and near the ectosymbiont 'Candidatus Desulfovibrio trichonymphae' in the anterior part of the host cell. The draft genome of 'Ca. Adiutrix intracellularis' obtained from a metagenomic library revealed the presence of a complete gene set encoding the Wood-Ljungdahl pathway, including two homologs of fdhF encoding hydrogenase-linked formate dehydrogenases (FDHH ) and all other components of the recently described hydrogen-dependent carbon dioxide reductase (HDCR) complex, which substantiates previous claims that the symbiont is capable of reductive acetogenesis from CO2 and H2 . The close phylogenetic relationship between the HDCR components and their homologs in homoacetogenic Firmicutes and Spirochaetes suggests that the deltaproteobacterium acquired the capacity for homoacetogenesis via lateral gene transfer. The presence of genes for nitrogen fixation and the biosynthesis of amino acids and cofactors indicate the nutritional nature of the symbiosis.

Lophomonas blattarum infection in immunocompetent patient.

Lophomonas blattarum (L. blattarum) is a protozoan parasite living in intestinal tracts of termites and cockroaches. Chen and Meng from China repoted first case of pulmonary L. blattarum infection in 1993. 137 cases have only been reported in literature between 1993 to 2013. Majority of these infections occur in immunocompromised patients and have been reported from China. We report a case of this rare entity in an immunocompetent young Indian male.

Phylogenetic diversity of Archaea in the intestinal tract of termites from different lineages.

Termites are among the few arthropods that emit methane to the atmosphere, which is a significant source of global greenhouse gas due to their huge biomass on earth. In this study, phylogenetic diversity of Archaea of five termite species from different lineages were analyzed based on 16S rRNA genes. Archaea associated with wood-feeding lower termite, R. chinensis were exclusively Methanobrevibacter in the order Methanobacteriales. This type of methanogens was also found in Nasutitermes sp. and Microcerotermes sp. but not in the fungus-cultivating termites, Odontotermes formosanus and Macrotermes barneyi, which harbor Archaea of the order Methanoplasmatales and Methanosarcinales in their guts. Archaeal diversity of wood-feeding higher termites was higher than wood-feeding lower termites. The highest archaeal diversity was found in Nasutitermes sp. In addition to methanogens affiliated with the orders Methanobacteriales, Methanomicrobiales, and Methanoplasmatales, 37% of archaeal clones were affiliated with non-methanogenic Thaumarchaeota. The results of this study will be significant for further understanding of symbiotic relationship between intestinal microbiota and termites.

“Methanoplasmatales,” Thermoplasmatales-Related Archaea in Termite Guts and Other Environments, Are the Seventh Order of Methanogens

The Euryarchaeota comprise both methanogenic and nonmethanogenic orders and many lineages of uncultivated archaea with unknown properties. One of these deep-branching lineages, distantly related to the Thermoplasmatales, has been discovered in various environments, including marine habitats, soil, and also the intestinal tracts of termites and mammals. By comparative phylogenetic analysis, we connected this lineage of 16S rRNA genes to a large clade of unknown mcrA gene sequences, a functional marker for methanogenesis, obtained from the same habitats. The identical topologies of 16S rRNA and mcrA gene trees and the perfect congruence of all branches, including several novel groups that we obtained from the guts of termites and cockroaches, strongly suggested that they stem from the same microorganisms. This was further corroborated by two highly enriched cultures of closely related methanogens from the guts of a higher termite (Cubitermes ugandensis) and a millipede (Anadenobolus sp.), which represented one of the arthropod-specific clusters in the respective trees. Numerous other pairs of habitat-specific sequence clusters were obtained from the guts of other termites and cockroaches but were also found in previously published data sets from the intestinal tracts of mammals (e.g., rumen cluster C) and other environments. Together with the recently described Methanomassiliicoccus luminyensis isolated from human feces, which falls into rice cluster III, the results of our study strongly support the idea that the entire clade of "uncultured Thermoplasmatales" in fact represents the seventh order of methanogenic archaea, for which the provisional name "Methanoplasmatales" is proposed.

Bacterial community composition of the gut microbiota of Cylindroiulus fulviceps (diplopoda) as revealed by molecular fingerprinting and cloning

Bacterial clone libraries of the gut microbiota of nurtured and starved Cylindroiulus fulviceps specimens displayed the predominance of the phyla Bacteroidetes (55 and 37 %, respectively) and Proteobacteria (40 and 35 %, respectively) and a high similarity to bacteria previously detected in the intestinal tract of termites and beetles, which are known to harbor symbiotic bacteria essential for digestive activity. Bacterial isolates were dominated by Proteobacteria (74 %), followed by members of the phyla Actinobacteria, Firmicutes and Bacteroidetes. PCR-DGGE fingerprints of the gut samples showed that intestinal bacteria were affected by starvation, although the change was not significant.

Niche heterogeneity determines bacterial community structure in the termite gut (Reticulitermes santonensis)

Differences in microenvironment and interactions of microorganisms within and across habitat boundaries should influence structure and diversity of the microbial communities within an ecosystem. We tested this hypothesis using the well characterized gut tract of the European subterranean termite Reticulitermes santonensis as a model. By cloning and sequencing analysis and molecular fingerprinting (terminal restriction fragment length polymorphism), we characterized the bacterial microbiota in the major intestinal habitats - the midgut, the wall of the hindgut paunch, the hindgut fluid and the intestinal protozoa. The bacterial community was very diverse (> 200 ribotypes) and comprised representatives of several phyla, including Firmicutes (mainly clostridia, streptococci and Mycoplasmatales-related clones), Bacteroidetes, Spirochaetes and a number of Proteobacteria, all of which were unevenly distributed among the four habitats. The largest group of clones fell into the so-called Termite group 1 (TG-1) phylum, which has no cultivated representatives. The majority of the TG-1 clones were associated with the protozoa and formed two phylogenetically distinct clusters, which consisted exclusively of clones previously retrieved from the gut of this and other Reticulitermes species. Also the other clones represented lineages of microorganisms that were exclusively recovered from the intestinal tract of termites. The termite specificity of these lineages was underscored by the finding that the closest relatives of the bacterial clones obtained from R. santonensis were usually derived also from the most closely related termites. Overall, differences in diversity between the different gut habitats and the uneven distribution of individual phylotypes support conclusively that niche heterogeneity is a strong determinant of the structure and spatial organization of the microbial community in the termite gut.

Passage and Survival of Chlamydospores of Phytophthora cinnamomi Rands, the Causal Agent of Forest Dieback Disease, Through the Gastrointestinal Tracts of Termites and Wild Birds

Chlamydospores of Phytophthora cinnamomi Rands have been shown to survive in the intestinal tracts of termites (Nasutitermes exitiosus) and two species of forest birds indigenous to West Australian jarrah forests. Viable chlamydospores were recovered from bird feces within the normal rate of passage time for food through the gut. The above factors would allow these creatures to function as vectors for the spores.