BACKGROUND: The contribution of the microbiome to pesticide breakdown in agricultural pests remains unclear. We analyzed the effect of pirimiphos-methyl (PM) on four geographically different cultures of the stored product pest mite Acarus siro (6 L, 6Tu, 6Tk and 6Z) under laboratory experiments. The effect of PM on mite mortality in the impregnated filter paper test was compared. RESULTS: The mite sensitivity to PM decreased in the order of 6 L, 6Tu, 6Tk, and 6Z. Then, the mites were cultured on PM residues (0.0125 and 1.25 µg·g-1), and population growth was compared to the control after 21 days of exposure. The comparison showed two situations: (i) increasing population growth for the most sensitive cultures (6 L and 6Tu), and (ii) no effect on mite population growth for tolerant cultures (6Z and 6Tk). The microbiome of mites was analyzed by quantification of 16S DNA copies based on quantitative polymerase chain reaction (qPCR) and by barcode sequencing of the V4 fragment of 16S DNA on samples of 30 individuals from the control and PM residues. The microbiome comprised primarily Solitalea-like organisms in all cultures, except for 6Z, followed by Bacillus, Staphylococcus, and Lactobacillus. The microbiomes of mite cultures did not change with increasing population density. The microbiome of cultures without any differences in population density showed differences in the microbiome composition. A Sodalis-like symbiont replaced Solitalea in the 1.25 µg·g-1 PM in the 6Tk culture. Sodalis and Bacillus prevailed in the microbiomes of PM-treated mites of 6Z culture, while Solitalea was almost absent. CONCLUSION: The results showed that the microbiome of A. siro differs in composition and in response to PM residues in the diet. The results indicate that Sodalis-like symbionts can help recover mites from pesticide-induced stress.

• Keywords
• Pesticide; Storage; Interaction; Tolerance; Symbionts,
• MeSH
• Acaridae * MeSH
• Bacteroidetes MeSH
• Humans MeSH
• Microbiota * MeSH
• Pesticide Residues * MeSH
• Mites * MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• pirimiphos methyl MeSH Browser
• Pesticide Residues * MeSH

Arthropod-associated microorganisms are important because they affect host fitness, protect hosts from pathogens, and influence the host's ability to vector pathogens. Stored product mites (Astigmata) often establish large populations in various types of food items, damaging the food by direct feeding and introducing contaminants, including their own bodies, allergen-containing feces, and associated microorganisms. Here we access the microbial structure and abundance in rearing diets, eggs, feces fraction, and mite bodies of 16 mite populations belonging to three species (Carpoglyphus lactis, Acarus siro, and Tyrophagus putrescentiae) using quantitative PCR and 16S ribosomal RNA (rRNA) gene amplicon sequencing. The mite microbiomes had a complex structure dominated by the following bacterial taxa (OTUs): (a) intracellular symbionts of the genera Cardinium and Wolbachia in the mite bodies and eggs; (b) putative gut symbionts of the genera Solitalea, Bartonella, and Sodalis abundant in mite bodies and also present in mite feces; (c) feces-associated or environmental bacteria of the genera Bacillus, Staphylococcus, and Kocuria in the diet, mite bodies, and feces. Interestingly and counterintuitively, the differences between microbial communities in various conspecific mite populations were higher than those between different mite species. To explain some of these differences, we hypothesize that the intracellular bacterial symbionts can affect microbiome composition in mite bodies, causing differences between microbial profiles. Microbial profiles differed between various sample types, such as mite eggs, bodies, and the environment (spent growth medium-SPGM). Low bacterial abundances in eggs may result in stochastic effects in parent-offspring microbial transmission, except for the intracellular symbionts. Bacteria in the rearing diet had little effect on the microbial community structure in SPGM and mite bodies. Mite fitness was positively correlated with bacterial abundance in SPGM and negatively correlated with bacterial abundances in mite bodies. Our study demonstrates critical host-microbe interactions, affecting all stages of mite growth and leading to alteration of the environmental microbiome. Correlational evidence based on absolute quantitation of bacterial 16S rRNA gene copies suggests that mite-associated microorganisms are critical for modulating important pest properties of mites by altering population growth.

• Keywords
• Allergen, Bartonella, Cardinium, Eggs, Feces, Feeding, Mite, Symbionts, Wolbachia,
• MeSH
• Acaridae classification   growth & development   microbiology   MeSH
• Bacteria classification   genetics   isolation & purification   MeSH
• Diet MeSH
• Feces microbiology   MeSH
• Phylogeny MeSH
• Host Microbial Interactions MeSH
• Microbiota * MeSH
• Ovum microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

The two common species of house dust mites (HDMs), Dermatophagoides farinae and D. pteronyssinus, are major sources of allergens in human dwellings worldwide. Many allergens from HDMs have been described, but their extracts vary in immunogens. Mite strains may differ in their microbiomes, which affect mite allergen expression and contents of bacterial endotoxins. Some bacteria, such as the intracellular symbiont Cardinium, can affect both the sex ratio and biochemical pathways of mites, resulting in abundance variations of mite allergens/immunogens. Here, we investigated the bacterial microbiomes of D. farinae and D. pteronyssinus males and females using barcode 16S rDNA sequencing, qPCR, and genomic data analysis. We found a single species of Cardinium associated with D. farinae strains from the USA, China and Europe. Cardinium had high abundance relative to other bacterial taxa and represented 99% of all bacterial DNA reads from female mites from the USA. Cardinium was also abundant with respect to the number of host cells-we estimated 10.4-11.8 cells of Cardinium per single female mite cell. In a European D. farinae strain, Cardinium was more prevalent in females than in males (representing 92 and 67% of all bacterial taxa in females and males, respectively). In contrast, D. pteronyssinus lacked any Cardinium species, and the microbiomes of male and female mites were similar. We produced a Cardinium genome assembly (1.48 Mb; GenBank: PRJNA555788, GCA_007559345.1) associated with D. farinae. The ascertained ubiquity and abundance of Cardinium strongly suggest that this intracellular bacterium plays an important biological role in D. farinae.

• Keywords
• Acaridida, Allergen production, Astigmata, Cardinium, Dermatophagoides pteronyssinus, Microbiome,
• MeSH
• Bacteroidetes isolation & purification   MeSH
• Dermatophagoides farinae microbiology   MeSH
• Dermatophagoides pteronyssinus microbiology   MeSH
• Genome, Bacterial * MeSH
• Microbiota MeSH
• Whole Genome Sequencing MeSH
• Symbiosis MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• China MeSH
• Europe MeSH
• United States 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.

• Keywords
• Bacteria, Dermatophagoides farinae, Dermatophagoides pteronyssinus, Diet, Fungi, Gut, Nutrition, Symbiosis, Yeasts,
• MeSH
• Bacteria * classification   MeSH
• RNA, Bacterial analysis   MeSH
• Species Specificity MeSH
• RNA, Fungal analysis   MeSH
• Fungi * classification   MeSH
• Real-Time Polymerase Chain Reaction MeSH
• Microbiota * MeSH
• Population Dynamics MeSH
• Pyroglyphidae microbiology   physiology   MeSH
• RNA, Ribosomal, 16S analysis   MeSH
• RNA, Ribosomal, 18S analysis   MeSH
• DNA Barcoding, Taxonomic MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• RNA, Bacterial MeSH
• RNA, Fungal MeSH
• RNA, Ribosomal, 16S MeSH
• RNA, Ribosomal, 18S MeSH

Blood feeding red poultry mites (RPM) serve as vectors of pathogenic bacteria and viruses among vertebrate hosts including wild birds, poultry hens, mammals, and humans. The microbiome of RPM has not yet been studied by high-throughput sequencing. RPM eggs, larvae, and engorged adult/nymph samples obtained in four poultry houses in Czechia were used for microbiome analyses by Illumina amplicon sequencing of the 16S ribosomal RNA (rRNA) gene V4 region. A laboratory RPM population was used as positive control for transcriptome analysis by pyrosequencing with identification of sequences originating from bacteria. The samples of engorged adult/nymph stages had 100-fold more copies of 16S rRNA gene copies than the samples of eggs and larvae. The microbiome composition showed differences among the four poultry houses and among observed developmental stadia. In the adults' microbiome 10 OTUs comprised 90 to 99% of all sequences. Bartonella-like bacteria covered between 30 and 70% of sequences in RPM microbiome and 25% bacterial sequences in transcriptome. The phylogenetic analyses of 16S rRNA gene sequences revealed two distinct groups of Bartonella-like bacteria forming sister groups: (i) symbionts of ants; (ii) Bartonella genus. Cardinium, Wolbachia, and Rickettsiella sp. were found in the microbiomes of all tested stadia, while Spiroplasma eriocheiris and Wolbachia were identified in the laboratory RPM transcriptome. The microbiomes from eggs, larvae, and engorged adults/nymphs differed. Bartonella-like symbionts were found in all stadia and sampling sites. Bartonella-like bacteria was the most diversified group within the RPM microbiome. The presence of identified putative pathogenic bacteria is relevant with respect to human and animal health issues while the identification of symbiontic bacteria can lead to new control methods targeting them to destabilize the arthropod host.

• Keywords
• Bartonella, Blood sucking, Mite, Poultry, Ricketsiella, Transmission, Tsukamurella, Wolbachia,
• MeSH
• Bacteria classification   genetics   isolation & purification   MeSH
• RNA, Bacterial genetics   MeSH
• Bartonella classification   genetics   isolation & purification   MeSH
• Species Specificity MeSH
• Microbiota * MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Mites growth & development   microbiology   MeSH
• DNA Barcoding, Taxonomic MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• RNA, Bacterial MeSH
• RNA, Ribosomal, 16S MeSH

Bacteria associated with mites influence their fitness, nutrition and reproduction. Previously, we found Solitalea-like (Sphingobacteriales) and Candidatus Cardinium (Cytophagales) bacteria in the stored product mite Acarus siro L. by cloning and using pyrosequencing. In this study, taxon-specific primers targeting 16S rRNA gene were used to detect and quantify the bacteria in mites and eggs of three A. siro populations. The specific probes for fluorescent in situ hybridization (FISH) were used to localize Solitalea-like and Cardinium bacteria in mite bodies. The population growth as an indirect estimator of fitness was used to describe the mite-bacteria interactions on (1) control diet; (2) rifampicin supplemented diet; (3) tetracycline supplemented diet; (4) rifampicin pretreated mites; (5) tetracycline pretreated mites. Solitalea-like 16S rRNA gene sequences from A. siro formed a separate cluster together with sequences from Tyrophagus putrescentiae. qPCR analysis indicated that number of Solitalea-like bacteria 16S rRNA gene copies was ca. 100× higher than that of Cardinium and the numbers differed between populations. FISH analysis localized Solitalea-like bacteria in the parenchymal tissues, mesodeum and food bolus of larvae, nymphs and adults. Solitalea-like, but not Cardinium bacteria were detected by taxon-specific primers in mites and eggs of all three investigated populations. None of the antibiotic treatments eliminated Solitalea-like bacteria in the A. siro populations tested. Rifampicin pretreatment significantly decreased the population growth. The numbers of Solitalea-like bacteria did not correlate with the population growth as a fitness indicator. This study demonstrated that A. siro can host Solitalea-like bacteria either alone or together with Cardinium. We suggest that Solitalea-like bacteria are shared by vertical transfer in A. siro populations.

• Keywords
• Antibiotic treatment, Stored product mites, Symbiont, Transmission of bacteria,
• MeSH
• Acaridae growth & development   microbiology   MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacteroidetes classification   genetics   physiology   MeSH
• DNA, Bacterial genetics   MeSH
• Genetic Fitness * MeSH
• In Situ Hybridization, Fluorescence MeSH
• Animal Feed analysis   MeSH
• Larva growth & development   microbiology   MeSH
• Nymph growth & development   microbiology   MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Symbiosis MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• DNA, Bacterial MeSH
• RNA, Ribosomal, 16S MeSH

BACKGROUND: Tyrophagus putrescentiae colonizes different human-related habitats and feeds on various post-harvest foods. The microbiota acquired by these mites can influence the nutritional plasticity in different populations. We compared the bacterial communities of five populations of T. putrescentiae and one mixed population of T. putrescentiae and T. fanetzhangorum collected from different habitats. MATERIAL: The bacterial communities of the six mite populations from different habitats and diets were compared by Sanger sequencing of cloned 16S rRNA obtained from amplification with universal eubacterial primers and using bacterial taxon-specific primers on the samples of adults/juveniles or eggs. Microscopic techniques were used to localize bacteria in food boli and mite bodies. The morphological determination of the mite populations was confirmed by analyses of CO1 and ITS fragment genes. RESULTS: The following symbiotic bacteria were found in compared mite populations: Wolbachia (two populations), Cardinium (five populations), Bartonella-like (five populations), Blattabacterium-like symbiont (three populations), and Solitalea-like (six populations). From 35 identified OTUs97, only Solitalea was identified in all populations. The next most frequent and abundant sequences were Bacillus, Moraxella, Staphylococcus, Kocuria, and Microbacterium. We suggest that some bacterial species may occasionally be ingested with food. The bacteriocytes were observed in some individuals in all mite populations. Bacteria were not visualized in food boli by staining, but bacteria were found by histological means in ovaria of Wolbachia-infested populations. CONCLUSION: The presence of Blattabacterium-like, Cardinium, Wolbachia, and Solitalea-like in the eggs of T. putrescentiae indicates mother to offspring (vertical) transmission. RESULTS of this study indicate that diet and habitats influence not only the ingested bacteria but also the symbiotic bacteria of T. putrescentiae.

• Keywords
• 16S rRNA, Blattabacterium, Tyrophagus putrescentiae, Wolbachia, bacteria, feeding, symbiont,
• Publication type
• Journal Article MeSH

BACKGROUND: Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata). The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria. METHODOLOGY AND PRINCIPAL FINDINGS: Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae) and associated bacterial community structure were assessed. Mites were treated by antibiotic supplementation (1 mg g(-1) of diet) for 21 days and numbers of mites and bacterial communities were analyzed and compared to the untreated control. Bacterial quantities, determined by real-time PCR, significantly decreased in antibiotic treated specimens from 5 to 30 times in A. siro and T. putrescentiae, while no decline was observed in L. destructor. Streptomycin treatment eliminated Bartonella-like bacteria in the both A. siro and T. putrescentiae and Cardinium in T. putrescentiae. Solitalea-like bacteria proportion increased in the communities of neomycin and streptomycin treated A. siro specimens. Kocuria proportion increased in the bacterial communities of ampicillin and streptomycin treated A. siro and neomycin and streptomycin treated L. destructor. CONCLUSIONS/SIGNIFICANCE: The work demonstrated the changes of mite associated bacterial community under antibiotic pressure in pests of medical importance. Pre-treatment of mites by 1 mg g(-1) antibiotic diets improved mite fitness as indicated accelerated population growth of A. siro pretreated streptomycin and neomycin and L. destructor pretreated by neomycin. All tested antibiotics supplemented to diets caused the decrease of mite growth rate in comparison to the control diet.

• MeSH
• Acaridae drug effects   growth & development   microbiology   MeSH
• Ampicillin pharmacology   MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacteria genetics   MeSH
• Population Density MeSH
• Microbial Consortia drug effects   MeSH
• Neomycin pharmacology   MeSH
• RNA, Ribosomal, 16S MeSH
• Streptomycin pharmacology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Ampicillin MeSH
• Anti-Bacterial Agents MeSH
• Neomycin MeSH
• RNA, Ribosomal, 16S MeSH
• Streptomycin MeSH