Blomia tropicalis is an allergen-producing mite in the human environment in tropical regions. The microbiome of B. tropicalis was described using the barcode sequencing region of V4 16S rDNA and genome assemblage. Mixta mediterraneensis, previously isolated from human skin swabs, was identified as a B. tropicalis gut symbiont based on genome assembly. The microbiome contains two bacteria, Staphylococcus and M. mediterraneensis. The number of M. mediterraneensis 16S DNA copies was 106 per mite and 109 per feces in the rearing chamber based on qPCR quantification. The profile of this bacterium reached 50% of reads in the mite gut and feces. Genomic analyses revealed that the bacterium has several metabolic pathways that suggest metabolic cooperation with the mite host in vitamin and amino acid synthesis, nitrogen recycling, and antimicrobial defense. Lysozyme is present in the symbiotic bacterium but absent in the mite. The B. tropicalis microbiome contained Staphylococcus, which accelerates mite population growth. Mites can digest Staphylococcus by using specific enzymes with hydrolytic functions against bacterial cell walls (chitinases and cathepsin D), leading to endocytosis of bacteria and their degradation in lysosomes and phagosomes. Gene expression analysis of B. tropicalis indicated that phagocytosis was mediated by the PI3-kinase/Akt pathway interacting with the invasins produced by M. mediterraneensis. Moreover, the symbiont had metabolic pathways that allowed it to recycle the mite metabolic waste product guanine, known as a mite attractant. The mite host symbiont enhances mite aggregation in the feces, and the fecal-oral transmission route is excepted.

• Klíčová slova
• Allergen, Digestion, Enzyme, Mite, Symbionts,
• MeSH
• alergeny * MeSH
• lidé MeSH
• roztoči * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alergeny * MeSH

Control of common scab disease can be reached by resistant cultivars or suppressive soils. Both mechanisms are likely to translate into particular potato microbiome profiles, but the relative importance of each is not known. Here, microbiomes of bulk and tuberosphere soil and of potato periderm were studied in one resistant and one susceptible cultivar grown in a conducive and a suppressive field. Disease severity was suppressed similarly by both means yet, the copy numbers of txtB gene (coding for a pathogenicity determinant) were similar in both soils but higher in periderms of the susceptible cultivar from conducive soil. Illumina sequencing of 16S rRNA genes for bacteria (completed by 16S rRNA microarray approach) and archaea, and of 18S rRNA genes for micro-eukarytes showed that in bacteria, the more important was the effect of cultivar and diversity decreased from resistant cultivar to bulk soil to susceptible cultivar. The major changes occurred in proportions of Actinobacteria, Chloroflexi, and Proteobacteria. In archaea and micro-eukaryotes, differences were primarily due to the suppressive and conducive soil. The effect of soil suppressiveness × cultivar resistance depended on the microbial community considered, but differed also with respect to soil and plant nutrient contents particularly in N, S and Fe.

• MeSH
• Actinobacteria klasifikace   genetika   růst a vývoj   patogenita   MeSH
• Archaea klasifikace   genetika   růst a vývoj   patogenita   MeSH
• Chloroflexi klasifikace   genetika   růst a vývoj   patogenita   MeSH
• dusík metabolismus   farmakologie   MeSH
• eukaryotické buňky metabolismus   MeSH
• faktory virulence genetika   metabolismus   MeSH
• genotypizační techniky MeSH
• mikrobiota genetika   MeSH
• náchylnost k nemoci imunologie   MeSH
• nemoci rostlin imunologie   mikrobiologie   MeSH
• odolnost vůči nemocem účinky léků   MeSH
• Proteobacteria klasifikace   genetika   růst a vývoj   patogenita   MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• RNA ribozomální 18S genetika   MeSH
• síra metabolismus   farmakologie   MeSH
• Solanum tuberosum účinky léků   imunologie   mikrobiologie   MeSH
• železo metabolismus   farmakologie   MeSH
• zemědělské plodiny MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dusík MeSH
• faktory virulence MeSH
• RNA ribozomální 16S MeSH
• RNA ribozomální 18S MeSH
• síra MeSH
• železo MeSH

Interactions with microorganisms might enable house dust mites (HDMs) to derive nutrients from difficult-to-digest structural proteins and to flourish in human houses. We tested this hypothesis by investigating the effects of changes in the mite culture growth and population of two HDM species on HDM microbiome composition and fitness. Growing cultures of laboratory and industrial allergen-producing populations of Dermatophagoides farinae (DFL and DFT, respectively) and Dermatophagoides pteronyssinus (DPL and DPT, respectively) were sampled at four time points. The symbiotic microorganisms of the mites were characterized by DNA barcode sequencing and quantified by qPCR using universal/specific primers. The population growth of mites and nutrient contents of mite bodies were measured and correlated with the changes in bacteria in the HDM microbiome. The results showed that both the population and culture age significantly influenced the microbiome profiles. Cardinium formed 93% and 32% of the total sequences of the DFL and DFT bacterial microbiomes, respectively, but this bacterial species was less abundant in the DPL and DPT microbiomes. Staphylococcus abundance was positively correlated with increased glycogen contents in the bodies of mites, and increased abundances of Aspergillus, Candida, and Kocuria were correlated with increased lipid contents in the bodies of mites. The xerophilic fungus Wallemia accounted for 39% of the fungal sequences in the DPL microbiome, but its abundance was low in the DPT, DFL, and DFT microbiomes. With respect to the mite culture age, we made three important observations: the mite population growth from young cultures was 5-8-fold higher than that from old cultures; specimens from old cultures had greater abundances of fungi and bacteria in their bodies; and yeasts predominated in the gut contents of specimens from young cultures, whereas filamentous mycelium prevailed in specimens from old cultures. Our results are consistent with the hypothesis that mites derive nutrients through associations with microorganisms.

• Klíčová slova
• Bacteria, Dermatophagoides farinae, Dermatophagoides pteronyssinus, Diet, Fungi, Gut, Nutrition, Symbiosis, Yeasts,
• MeSH
• Bacteria * klasifikace   MeSH
• bakteriální RNA analýza   MeSH
• druhová specificita MeSH
• fungální RNA analýza   MeSH
• houby * klasifikace   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• mikrobiota * MeSH
• populační dynamika MeSH
• Pyroglyphidae mikrobiologie   fyziologie   MeSH
• RNA ribozomální 16S analýza   MeSH
• RNA ribozomální 18S analýza   MeSH
• taxonomické DNA čárové kódování MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální RNA MeSH
• fungální RNA MeSH
• RNA ribozomální 16S MeSH
• RNA ribozomální 18S MeSH

The effect of short-term nutrient deprivation was studied in five populations of the mite Tyrophagus putrescentiae with different microbiomes. The fresh weight, nutrient status, respiration, and population growth of the mites were observed for the five mite population-scale samples. The starvation caused the larvae and nymphs to be eliminated, resulting in a significant increase in the fresh weight of starved adult specimens. Three populations were negatively influenced by starvation, and the starved specimens were characterized by a decrease in nutrient status, respiration, and population growth. One population was not influenced or was slightly influenced by starvation, which had no effect on population growth or nutrient contents but caused a significant decrease in respiration. One population was positively influenced by starvation; the population growth increased in starved specimens, and starvation had no effect on respiration. Although starvation altered the bacterial profiles of the microbiomes, these differences were much smaller than those between the populations. The bacterial profiles of Staphylococcus, Bacillus, Kocuria, Brevibacterium, and unidentified Micrococcaceae and Enterobacteriaceae increased in starved specimens, whereas those of Bartonella and Solitalea-like genera were reduced in the starved mite populations. The profiles of the intracellular symbiont Cardinium decreased in the starved specimens, and the Wolbachia profile changes were dependent on the mite population. In mite populations, when the symbionts were rare, their profiles varied stochastically. Correlations between changes in the profiles of the bacterial taxa and mite fitness parameters, including nutrient status (lipids, proteins, saccharides, and glycogen contents), mite population growth, and respiration, were observed. Although the microbiomes were resistant to the perturbations caused by nutrition deficiency, the responses of the mites differed in terms of their population growth, respiration, and nutrient status.

• Klíčová slova
• Coprophagy, Fitness, Gut, Mites, Starvation, Symbionts,
• MeSH
• Acaridae mikrobiologie   fyziologie   MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   MeSH
• fyziologie bakterií MeSH
• hostitelská specificita MeSH
• mikrobiota * MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH