Vermicomposting has been recognized as a sustainable solution for the managing of organic waste, primarily because of the bacterial communities that drive microbial decomposition. However, while the roles of abundant bacteria in composting processes are well-documented, the contributions of rare bacteria remain underexplored. In this study, we investigated the diversity and composition of abundant and rare bacterial communities in gut of Eudrilus eugeniae and resulting vermicompost, comparing okara as a single substrate compared to a combination of more substrates, such as kitchen waste or okara and kitchen waste. Amplicon sequencing revealed a total of 3085 operational taxonomic units (OTUs), comprising 188 abundant OTUs and 2127 rare OTUs. Significant differences in bacterial community composition were observed between vermicompost and the earthworm gut, particularly in the rare bacterial communities, with distinct abundances of Gemmatimonadota, Desulfobacteria, Myxococcota, Acidobacteria, and Firmicutes. Interestingly, no significant differences were found between treatments in the abundant bacterial communities, suggesting that okara alone can sustain a bacterial community comparable to mixed substrates. However, rare bacterial communities were more sensitive to substrate variation, with okara fostering distinct rare microbial populations in the vermicompost and earthworm gut. Our results indicate okara can support both abundant and rare bacteria, producing compost with similar physico-chemical properties to those derived from mixed substrates. The study highlights the importance of rare bacterial communities in vermicomposting and demonstrates the potential of okara as a valuable resource for sustainable waste management and soil improvement.

• Klíčová slova
• Eudrilus eugeniae, Amplicon sequencing, Microbial diversity, Okara, Rare bacteria, Vermicomposting,
• Publikační typ
• časopisecké články MeSH

Closely related host species share similar symbionts, but the effects of host genetic admixture and environmental conditions on these communities remain largely unknown. We investigated the influence of host genetic admixture and environmental factors on the intestinal prokaryotic and eukaryotic communities (fungi, parasites) of two house mouse subspecies (Mus musculus domesticus and M. m. musculus) and their hybrids in two settings: (i) wild-caught mice from the European hybrid zone and (ii) wild-derived inbred mice in a controlled laboratory environment before and during a community perturbation (infection). In wild-caught mice, environmental factors strongly predicted the overall microbiome composition. Subspecies' genetic distance significantly influenced the overall microbiome composition, and each component (bacteria, parasites and fungi). While hybridization had a weak effect, it significantly impacted fungal composition. We observed similar patterns in wild-derived mice, where genetic distances and hybridization influenced microbiome composition, with fungi being more stable to infection-induced perturbations than other microbiome components. Subspecies' genetic distance has a stronger and consistent effect across microbiome components than differences in expected heterozygosity among hybrids, suggesting that host divergence and host filtering play a key role in microbiome divergence, influenced by environmental factors. Our findings offer new insights into the eco-evolutionary processes shaping host-microbiome interactions.

• Klíčová slova
• host–microbiome interactions, hybridization, microbiome, spatial environment, species barriers,
• MeSH
• biologická evoluce MeSH
• hybridizace genetická * MeSH
• interakce mikroorganismu a hostitele MeSH
• mikrobiota MeSH
• myši MeSH
• střevní mikroflóra MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Although metagenomic sequencing is now the preferred technique to study microbiome-host interactions, analyzing and interpreting microbiome sequencing data presents challenges primarily attributed to the statistical specificities of the data (e.g., sparse, over-dispersed, compositional, inter-variable dependency). This mini review explores preprocessing and transformation methods applied in recent human microbiome studies to address microbiome data analysis challenges. Our results indicate a limited adoption of transformation methods targeting the statistical characteristics of microbiome sequencing data. Instead, there is a prevalent usage of relative and normalization-based transformations that do not specifically account for the specific attributes of microbiome data. The information on preprocessing and transformations applied to the data before analysis was incomplete or missing in many publications, leading to reproducibility concerns, comparability issues, and questionable results. We hope this mini review will provide researchers and newcomers to the field of human microbiome research with an up-to-date point of reference for various data transformation tools and assist them in choosing the most suitable transformation method based on their research questions, objectives, and data characteristics.

• Klíčová slova
• compositionality, data preprocessing, human microbiome, machine learning, metagenomics data, normalization,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Termites are key decomposers of dead plant material involved in the organic matter recycling process in warm terrestrial ecosystems. Due to their prominent role as urban pests of timber, research efforts have been directed toward biocontrol strategies aimed to use pathogens in their nest. However, one of the most fascinating aspects of termites is their defense strategies that prevent the growth of detrimental microbiological strains in their nests. One of the controlling factors is the nest allied microbiome. Understanding how allied microbial strains protect termites from pathogen load could provide us with an enhanced repertoire for fighting antimicrobial-resistant strains or mining for genes for bioremediation purposes. However, a necessary first step is to characterize these microbial communities. To gain a deeper understanding of the termite nest microbiome, we used a multi-omics approach for dissecting the nest microbiome in a wide range of termite species. These cover several feeding habits and three geographical locations on two tropical sides of the Atlantic Ocean known to host hyper-diverse communities. Our experimental approach included untargeted volatile metabolomics, targeted evaluation of volatile naphthalene, a taxonomical profile for bacteria and fungi through amplicon sequencing, and further diving into the genetic repertoire through a metagenomic sequencing approach. Naphthalene was present in species belonging to the genera Nasutitermes and Cubitermes. We investigated the apparent differences in terms of bacterial community structure and discovered that feeding habits and phylogenetic relatedness had a greater influence than geographical location. The phylogenetic relatedness among nests' hosts influences primarily bacterial communities, while diet influences fungi. Finally, our metagenomic analysis revealed that the gene content provided both soil-feeding genera with similar functional profiles, while the wood-feeding genus showed a different one. Our results indicate that the nest functional profile is largely influenced by diet and phylogenetic relatedness, irrespective of geographical location.

• Klíčová slova
• metabarcoding, metabolomics, metagenomic sequencing, phylogenetic relatedness, termite diet, termite nest microbiome,
• Publikační typ
• časopisecké články MeSH

Helicobacter pylori (H. pylori) is a Gram-negative pathogen as a carcinogen of the class Ι, with unique genetic diversity and wide geographic differences. The high incidence of gastric cancer in East Asia may be related to the bacterial genotype. It is of great significance that the genome of H. pylori in East Asia is widely collected. Therefore, we combined two sequencing technologies (PacBio and Illumina HiSeq 4000) and multiple databases to sequence and annotate the whole genome of H. pylori GZ7 isolated from a gastric cancer patient in Guizhou, China. Furthermore, this sequence was further compared with the genome sequence of 23 H. pylori strains isolated from different regions through collinearity comparison, specific gene analysis, phylogenetic tree construction, etc. The results showed that the genome of H. pylori GZ7 consists of 1,579,995 bp circle chromosomes with a GC content of 39.51%. This chromosome has 1,572 coding sequences, three antibiotic resistance genes, five prophages, and 198 virulence genes. The comparative genome analyses showed that H. pylori GZ7 has 53 specific genes compared to the other 23 strains. Most of these specific genes have not been annotated and characterized until now, whose research may provide insights into the biological activities of this strain. H. pylori GZ7 has the closest genetic relationship with H. pylori F30, and the farthest genetic relationship with H. pylori ELS37, which indicates that H. pylori genomes have geographical differences. This information may provide a molecular basis and guidance for constructing diagnostic methods for H. pylori and researching subsequent experiments.

• Klíčová slova
• Comparative genomics, Gene annotation, Helicobacter pylori, Whole-genome sequencing,
• MeSH
• fylogeneze MeSH
• genom bakteriální MeSH
• Helicobacter pylori * MeSH
• infekce vyvolané Helicobacter pylori * mikrobiologie   MeSH
• lidé MeSH
• nádory žaludku * genetika   mikrobiologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Ticks are obligate hematophagous arthropods transmitting a wide range of pathogens to humans and animals. They also harbor a non-pathogenic microbiota, primarily in the ovaries and the midgut. In the previous study on Ixodes ricinus, we used a culture-independent approach and showed a diverse but quantitatively poor midgut bacterial microbiome. Our analysis also revealed the absence of a core microbiome, suggesting an environmental origin of the tick midgut microbiota. METHODS: A bacterial analysis of the midgut of adult females collected by flagging from two localities in the Czech Republic was performed. Using the culture-independent approach, we tested the hypothesis that the midgut microbiome is of the environmental origin. We also cultured indigenous bacteria from the tick midgut and used these to feed ticks artificially in an attempt to manipulate the midgut microbiome. RESULTS: The midgut showed a very low prevalence and abundance of culturable bacteria, with only 37% of ticks positive for bacteria. The culture-independent approach revealed the presence of Borrelia sp., Spiroplasma sp., Rickettsia sp., Midichloria sp. and various mainly environmental Gram-positive bacterial taxa. The comparison of ticks from two regions revealed that the habitat influenced the midgut bacterial diversity. In addition, the midgut of ticks capillary fed with the indigenous Micrococcus luteus (Gram-positive) and Pantoea sp. (Gram-negative) could not be colonized due to rapid and effective clearance of both bacterial taxa. CONCLUSIONS: The midgut microbiome of I. ricinus is diverse but low in abundance, with the exception of tick-borne pathogens and symbionts. The environment impacts the diversity of the tick midgut microbiome. Ingested extracellular environmental bacteria are rapidly eliminated and are not able to colonize the gut. We hypothesize that bacterial elimination triggered in the midgut of unfed adult females is critical to maintain low microbial levels during blood-feeding.

• Klíčová slova
• Capillary feeding, Culturing, High-throughput sequencing, Ixodes ricinus, Microbiome, Microbiome manipulation, Midgut,
• MeSH
• Borrelia * MeSH
• klíště * mikrobiologie   MeSH
• mikrobiota * MeSH
• Rickettsia * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

Wetlands are the largest natural source of terrestrial CH4 emissions. Afforestation can enhance soil CH4 oxidation and decrease methanogenesis, yet the driving mechanisms leading to these effects remain unclear. We analyzed the structures of communities of methanogenic and methanotrophic microbes, quantification of mcrA and pmoA genes, the soil microbial metagenome, soil properties and CH4 fluxes in afforested and non-afforested areas in the marshland of the Yangtze River. Compared to the non-afforested land use types, net CH4 emission decreased from bare land, natural vegetation and 5-year forest plantation and transitioned to net CH4 sinks in the 10- and 20-year forest plantations. Both abundances of mcrA and pmoA genes decreased significantly with increasing plantation age. By combining random forest analysis and structural equation modeling, our results provide evidence for an important role of the abundance of functional genes related to methane production in explaining the net CH4 flux in this ecosystem. The structures of methanogenic and methanotrophic microbial communities were of lower importance as explanatory factors than functional genes in terms of in situ CH4 flux. We also found a substantial interaction between functional genes and soil properties in the control of CH4 flux, particularly soil particle size. Our study provides empirical evidence that microbial community function has more explanatory power than taxonomic microbial community structure with respect to in situ CH4 fluxes. This suggests that focusing on gene abundances obtained, e.g., through metagenomics or quantitative/digital PCR could be more effective than community profiling in predicting CH4 fluxes, and such data should be considered for ecosystem modeling.

• Klíčová slova
• CH4 flux, methanogens, methanotrophs, soil metagenome, soil particle size composition,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The lone star tick (Amblyomma americanum), an important vector of a wide range of human and animal pathogens, is very common throughout the East and Midwest of the USA. Ticks are known to carry non-pathogenic bacteria that may play a role in their vector competence for pathogens. Several previous studies using the high throughput sequencing (HTS) technologies reported the commensal bacteria in a tick midgut as abundant and diverse. In contrast, in our preliminary survey of the field collected adult lone star ticks, we found the number of culturable/viable bacteria very low. METHODS: We aimed to analyze the bacterial community of A. americanum by a parallel culture-dependent and a culture-independent approach applied to individual ticks. RESULTS: We analyzed 94 adult females collected in eastern Kansas and found that 60.8% of ticks had no culturable bacteria and the remaining ticks carried only 67.7 ± 42.8 colony-forming units (CFUs)/tick representing 26 genera. HTS of the 16S rRNA gene resulted in a total of 32 operational taxonomic units (OTUs) with the dominant endosymbiotic genera Coxiella and Rickettsia (> 95%). Remaining OTUs with very low abundance were typical soil bacterial taxa indicating their environmental origin. CONCLUSIONS: No correlation was found between the CFU abundance and the relative abundance from the culture-independent approach. This suggests that many culturable taxa detected by HTS but not by culture-dependent method were not viable or were not in their culturable state. Overall, our HTS results show that the midgut bacterial community of A. americanum is very poor without a core microbiome and the majority of bacteria are endosymbiotic.

• Klíčová slova
• Bacterial diversity, Culturing, High throughput sequencing, Microbiome, Midgut,
• MeSH
• Amblyomma mikrobiologie   MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   MeSH
• fylogeneze MeSH
• mikrobiota genetika   MeSH
• počet mikrobiálních kolonií statistika a číselné údaje   MeSH
• RNA ribozomální 16S genetika   MeSH
• sekvenční analýza DNA MeSH
• vysoce účinné nukleotidové sekvenování * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• RNA ribozomální 16S MeSH

Bark beetles often serve as forest damaging agents, causing landscape-level mortality. Understanding the biology and ecology of beetles are important for both, gathering knowledge about important forest insects and forest protection. Knowledge about the bark beetle gut-associated bacteria is one of the crucial yet surprisingly neglected areas of research with European tree-killing bark beetles. Hence, in this study, we survey the gut bacteriome from five Ips and one non-Ips bark beetles from Scolytinae. Results reveal 69 core bacterial genera among five Ips beetles that may perform conserved functions within the bark beetle holobiont. The most abundant bacterial genera from different bark beetle gut include Erwinia, Sodalis, Serratia, Tyzzerella, Raoultella, Rahnella, Wolbachia, Spiroplasma, Vibrio, and Pseudoxanthomonas. Notable differences in gut-associated bacterial community richness and diversity among the beetle species are observed. Furthermore, the impact of sampling location on the overall bark beetle gut bacterial community assemblage is also documented, which warrants further investigations. Nevertheless, our data expanded the current knowledge about core gut bacterial communities in Ips bark beetles and their putative function such as cellulose degradation, nitrogen fixation, detoxification of defensive plant compounds, and inhibition of pathogens, which could serve as a basis for further metatranscriptomics and metaproteomics investigations.

• MeSH
• Bacteria klasifikace   genetika   metabolismus   MeSH
• brouci metabolismus   mikrobiologie   MeSH
• ekologie MeSH
• fixace dusíku MeSH
• fylogeneze MeSH
• lesy MeSH
• střevní mikroflóra * MeSH
• stromy parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Kissing bugs (Triatominae) are blood-feeding insects best known as the vectors of Trypanosoma cruzi, the causative agent of Chagas' disease. Considering the high epidemiological relevance of these vectors, their biology and bacterial symbiosis remains surprisingly understudied. While previous investigations revealed generally low individual complexity but high among-individual variability of the triatomine microbiomes, any consistent microbiome determinants have not yet been identified across multiple Triatominae species. METHODS: To obtain a more comprehensive view of triatomine microbiomes, we investigated the host-microbiome relationship of five Triatoma species sampled from white-throated woodrat (Neotoma albigula) nests in multiple locations across the USA. We applied optimised 16S rRNA gene metabarcoding with a novel 18S rRNA gene blocking primer to a set of 170 T. cruzi-negative individuals across all six instars. RESULTS: Triatomine gut microbiome composition is strongly influenced by three principal factors: ontogeny, species identity, and the environment. The microbiomes are characterised by significant loss in bacterial diversity throughout ontogenetic development. First instars possess the highest bacterial diversity while adult microbiomes are routinely dominated by a single taxon. Primarily, the bacterial genus Dietzia dominates late-stage nymphs and adults of T. rubida, T. protracta, and T. lecticularia but is not present in the phylogenetically more distant T. gerstaeckeri and T. sanguisuga. Species-specific microbiome composition, particularly pronounced in early instars, is further modulated by locality-specific effects. In addition, pathogenic bacteria of the genus Bartonella, acquired from the vertebrate hosts, are an abundant component of Triatoma microbiomes. CONCLUSION: Our study is the first to demonstrate deterministic patterns in microbiome composition among all life stages and multiple Triatoma species. We hypothesise that triatomine microbiome assemblages are produced by species- and life stage-dependent uptake of environmental bacteria and multiple indirect transmission strategies that promote bacterial transfer between individuals. Altogether, our study highlights the complexity of Triatominae symbiosis with bacteria and warrant further investigation to understand microbiome function in these important vectors. Video abstract.

• Klíčová slova
• Bacteria, Blood, Hematophagous, Insect, Microbiome, Ontogeny, Pathogen, Triatominae, Vector,
• MeSH
• Chagasova nemoc parazitologie   MeSH
• divoká zvířata klasifikace   mikrobiologie   MeSH
• mikrobiota genetika   fyziologie   MeSH
• RNA ribozomální 16S genetika   MeSH
• Triatominae klasifikace   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• audiovizuální média MeSH
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• RNA ribozomální 16S MeSH