# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 8130 | 0 | 0.9726 | Garden fruit chafer (Pachnoda sinuata L.) accelerates recycling and bioremediation of animal waste. Bioconversion of livestock wastes using insect larvae represents an emerging and effective strategy for waste management. However, knowledge on the role of the garden fruit chafer (Pachnoda sinuataL.) in waste recycling and influence on the diversity ofmicrobial community infrass fertilizeris limited. Here, we determined whether and to what extent the conversion of cattle dung into insect frass fertilizer byP. sinuatainfluences the frass' microbial community and its associated antibiotic resistance genes abundance. Pachnoda sinuata larvae were used to valorise cattle dung into frass fertilizer; samples were collected weekly to determine the composition of bacteria and fungi, and antibiotic resistant genes using molecular tools. Results revealed that bioconversion of cattle dung byP. sinuatalarvae significantly increased the richness of beneficial bacteria in the frass fertilizer by 2.5-folds within 28 days, but fungal richness did not vary during the study. Treatment of cattle dung withP. sinuatalarvae caused 2 - 3-folds decrease in the genes conferring resistance to commonly used antibiotics such as aminoglycoside, diaminopyrimidine, multidrug, sulfonamide and tetracycline within 14 days. Furthermore, the recycling cattle dung using considerably reduced the abundance of mobile genetic elements known to play critical roles in the horizontal transfer of antibiotic resistance genes between organisms. This studyhighlights the efficiency ofsaprohytic insects in recycling animal manure and suppressing manure-borne pathogens in the organic fertilizer products, opening new market opportunities for innovative and safe bio-based products and achieving efficient resource utilization in a circular and green economy. | 2024 | 37989012 |
| 3737 | 1 | 0.9718 | In vitro development and transfer of resistance to chlortetracycline in Bacillus subtilis. The present criteria and rules controlling the approval of the use of probiotics are limited to antibiotic resistance patterns and the presence of antibiotic resistance genes in bacteria. There is little information available in the literature regarding the risk of the usage of probiotics in the presence of antibiotic pressure. In this study we investigated the development and transfer of antibiotic resistance in Bacillus subtilis selected in vitro by chlortetracycline in a stepwise manner. Bacillus subtilis was exposed to increasing concentrations of chlortetracyclineto induce in vitro resistance to chlortetracycline, and the minimal inhibitory concentrations were determinedfor the mutants. Resistant B. subtilis were conjugated with Escherichia coli NK5449 and Enterococcus faecalis JH2-2 using the filter mating. Three B. subtilis tetracycline resistant mutants (namely, BS-1, BS-2, and BS-3) were derived in vitro. A tetracycline resistant gene, tet (K), was found in the plasmids of BS-1 and BS-2. Three conjugates (BS-1N, BS-2N, and BS-3N) were obtained when the resistant B. subtilis was conjugated with E. coli NK5449. The conjugation frequencies for the BS-1N, BS-2N, and BS-3N conjugates were 4.57×10(-7), 1.4×10(-7), and 1.3×10(-8), respectively. The tet(K) gene was found only in the plasmids of BS-1N. These results indicate that long-term use of probiotics under antibiotic selection pressure could cause antibiotic resistance, and the resistance gene could be transferred to other bacteria. The risk arising from the use of probiotics under antibiotic pressure should be considered in the criteria and rules for the safety assessment of probiotics. | 2012 | 23124749 |
| 8787 | 2 | 0.9716 | Improved resistance against Botrytis cinerea by grapevine-associated bacteria that induce a prime oxidative burst and phytoalexin production. Bacteria such as Pantoea agglomerans (Pa-AF2), Bacillus subtilis (Bs-271), Acinetobacter lwoffii (Al-113), and Pseudomonas fluorescens (Pf-CT2), originating from the vineyard, can induce defense responses and enhance resistance of grapevine against the fungal pathogen Botrytis cinerea. The perception of these bacteria by plant cells or tissues in relation to their activities remains unknown. In this study, we examined the relationships between the activity of each bacterium to induce or prime some defense responses, and its effectiveness to induce resistance in grapevine against B. cinerea. We showed that all selected bacteria are capable of inducing early oxidative burst and phytoalexin (trans-resveratrol and trans-ε-viniferin) production in grapevine cells and leaves. Pf-CT2 and Al-113 induced higher H(2)O(2) and trans-resveratrol accumulations, and were able to further prime plants for accelerated phytoalexin production after B. cinerea challenge. These two bacteria were also the most effective in inducing local and systemic resistance. A similar level of induced resistance was observed with live Pa-AF2 which also induced but not primed a greater accumulation of trans-resveratrol. However, Bs-271, which was less effective in inducing resistance, induced a lower trans-resveratrol synthesis, without priming activity. Treatment of grapevine cells with growing medium or crude extract of the bacteria quickly and strongly enhanced oxidative burst compared with the live bacteria. However, both treatments resulted in comparable amounts of phytoalexins and induced local and systemic resistance to B. cinerea as compared with those induced by living bacteria, with extracts from Pf-CT2 and Al-113 being the most effective. Together, these results indicate that induced resistance can be improved by treatment with bacteria or derived compounds which induced or primed plants for enhanced phytoalexin accumulation. | 2011 | 21425931 |
| 8115 | 3 | 0.9710 | Effects of reductive soil disinfestation on potential pathogens and antibiotic resistance genes in soil. Reductive soil disinfestation (RSD) is commonly employed for soil remediation in greenhouse cultivation. However, its influence on antibiotic resistance genes (ARGs) in soil remains uncertain. This study investigated the dynamic changes in soil communities, potential bacterial pathogens, and ARG profiles under various organic material treatments during RSD, including distillers' grains, potato peel, peanut vine, and peanut vine combined with charcoal. Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens (P < 0.05). The relative abundance of high-risk ARGs decreased by 10.7%-30.6% after RSD treatments, the main decreased ARG subtypes were AAC(3)_Via, dfrA1, ErmB, lnuB, aadA. Actinobacteria was the primary host of ARGs and was suppressed by RSD. Soil physicochemical properties, such as total nitrogen, soil pH, total carbon, were crucial factors affecting ARG profiles. Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil. | 2025 | 39306413 |
| 6046 | 4 | 0.9709 | Safety Evaluations of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI. Over the past decade, a variety of lactic acid bacteria have been commercially available to and steadily used by consumers. However, recent studies have shown that some lactic acid bacteria produce toxic substances and display properties of virulence. To establish safety guidelines for lactic acid bacteria, the Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) has suggested that lactic acid bacteria be characterized and proven safe for consumers’ health via multiple experiments (e.g., antibiotic resistance, metabolic activity, toxin production, hemolytic activity, infectivity in immune-compromised animal species, human side effects, and adverse-outcome analyses). Among the lactic acid bacteria, Bifidobacterium and Lactobacillus species are probiotic strains that are most commonly commercially produced and actively studied. Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI have been used in global functional food markets (e.g., China, Germany, Jordan, Korea, Lithuania, New Zealand, Poland, Singapore, Thailand, Turkey, and Vietnam) as nutraceutical ingredients for decades, without any adverse events. However, given that the safety of some newly screened probiotic species has recently been debated, it is crucial that the consumer safety of each commercially utilized strain be confirmed. Accordingly, this paper details a safety assessment of B. bifidum BGN4 and B. longum BORI via the assessment of ammonia production, hemolysis of blood cells, biogenic amine production, antimicrobial susceptibility pattern, antibiotic resistance gene transferability, PCR data on antibiotic resistance genes, mucin degradation, genome stability, and possession of virulence factors. These probiotic strains showed neither hemolytic activity nor mucin degradation activity, and they did not produce ammonia or biogenic amines (i.e., cadaverine, histamine or tyramine). B. bifidum BGN4 and B. longum BORI produced a small amount of putrescine, commonly found in living cells, at levels similar to or lower than that found in other foods (e.g., spinach, ketchup, green pea, sauerkraut, and sausage). B. bifidum BGN4 showed higher resistance to gentamicin than the European Food Safety Authority (EFSA) cut-off. However, this paper shows the gentamicin resistance of B. bifidum BGN4 was not transferred via conjugation with L. acidophilus ATCC 4356, the latter of which is highly susceptible to gentamicin. The entire genomic sequence of B. bifidum BGN4 has been published in GenBank (accession no.: CP001361.1), documenting the lack of retention of plasmids capable of transferring an antibiotic-resistant gene. Moreover, there was little genetic mutation between the first and 25th generations of B. bifidum BGN4. Tetracycline-resistant genes are prevalent among B. longum strains; B. longum BORI has a tet(W) gene on its chromosome DNA and has also shown resistance to tetracycline. However, this research shows that its tetracycline resistance was not transferred via conjugation with L. fermentum AGBG1, the latter of which is highly sensitive to tetracycline. These findings support the continuous use of B. bifidum BGN4 and B. longum BORI as probiotics, both of which have been reported as safe by several clinical studies, and have been used in food supplements for many years. | 2018 | 29747442 |
| 6728 | 5 | 0.9708 | Relationships between Root Pathogen Resistance, Abundance and Expression of Pseudomonas Antimicrobial Genes, and Soil Properties in Representative Swiss Agricultural Soils. Strains of Pseudomonas that produce antimicrobial metabolites and control soilborne plant diseases have often been isolated from soils defined as disease-suppressive, i.e., soils, in which specific plant pathogens are present, but plants show no or reduced disease symptoms. Moreover, it is assumed that pseudomonads producing antimicrobial compounds such as 2,4-diacetylphloroglucinol (DAPG) or phenazines (PHZ) contribute to the specific disease resistance of suppressive soils. However, pseudomonads producing antimicrobial metabolites are also present in soils that are conducive to disease. Currently, it is still unknown whether and to which extent the abundance of antimicrobials-producing pseudomonads is related to the general disease resistance of common agricultural soils. Moreover, virtually nothing is known about the conditions under which pseudomonads express antimicrobial genes in agricultural field soils. We present here results of the first side-by-side comparison of 10 representative Swiss agricultural soils with a cereal-oriented cropping history for (i) the resistance against two soilborne pathogens, (ii) the abundance of Pseudomonas bacteria harboring genes involved in the biosynthesis of the antimicrobials DAPG, PHZ, and pyrrolnitrin on roots of wheat, and (iii) the ability to support the expression of these genes on the roots. Our study revealed that the level of soil disease resistance strongly depends on the type of pathogen, e.g., soils that are highly resistant to Gaeumannomyces tritici often are highly susceptible to Pythium ultimum and vice versa. There was no significant correlation between the disease resistance of the soils, the abundance of Pseudomonas bacteria carrying DAPG, PHZ, and pyrrolnitrin biosynthetic genes, and the ability of the soils to support the expression of the antimicrobial genes. Correlation analyses indicated that certain soil factors such as silt, clay, and some macro- and micronutrients influence both the abundance and the expression of the antimicrobial genes. Taken together, the results of this study suggests that pseudomonads producing DAPG, PHZ, or pyrrolnitrin are present and abundant in Swiss agricultural soils and that the soils support the expression of the respective biosynthetic genes in these bacteria to various degrees. The precise role that these pseudomonads play in the general disease resistance of the investigated agricultural soils remains elusive. | 2017 | 28424714 |
| 8068 | 6 | 0.9708 | Safety of composts consisting of hydrothermally treated penicillin fermentation residue: Degradation products, antibiotic resistance genes and bacterial diversity. Combining hydrothermal treatment and composting is an effective method to dispose of penicillin fermentation residue (PFR), but the safety and related mechanism are still unclear. In this study, penicillin solution was hydrothermally treated to decipher its degradation mechanism, and then hydrothermally treated PFR (HT-PFR) was mixed with bulking agents at ratios of 2:0 (CK), 2:1.5 (T1), and 2:5 (T2) to determine the absolute abundance of antibiotic resistance genes (ARGs) and the succession of bacterial community. Results showed that penicillin was degraded to several new compounds without the initial lactam structure after hydrothermal treatment. During composting, temperature and pH of the composts increased with the raising of HT-PFR proportion, except the pH at days 2. After 52 days of composting, the absolute copies of ARGs (blaTEM, blaCMY2, and blaSFO) and the relative abundance of bacteria related to pathogens were reduced significantly (P < 0.05). Especially, the total amount of ARGs in the samples of CK and T1 were decreased to equal level (around 5 log(10) copies/g), which indicated that more ARGs were degraded in the latter by the composting process. In the CK samples, Bacteroidetes and Proteobacteria accounted for ~69.8% of the total bacteria, but they were gradually replaced by Firmicutes with increasing proportions of HT-PFR, which can be caused by the high protein content in PFR. Consisting with bacterial community, more gram-positive bacteria were observed in T1 and T2, and most of them are related to manganese oxidation and chitinolysis. As composting proceeded, bacteria having symbiotic or pathogenic relationships with animals and plants were reduced, but those related to ureolysis and cellulolysis were enriched. Above all, hydrothermal treatment is effective in destroying the lactam structure of penicillin, which makes that most ARGs and pathogenic bacteria are eliminated in the subsequent composting. | 2021 | 34492529 |
| 18 | 7 | 0.9706 | Antivirulence effects of cell-free culture supernatant of endophytic bacteria against grapevine crown gall agent, Agrobacterium tumefaciens, and induction of defense responses in plantlets via intact bacterial cells. BACKGROUND: Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control plant diseases via the use of several mechanisms. This research examined the potential for controlling crown gall by three endophytic bacteria that were previously isolated from healthy cultivated and wild grapevines including Pseudomonas kilonensis Ba35, Pseudomonas chlororaphis Ba47, and Serratia liquefaciens Ou55. RESULT: At various degrees, three endophytic bacteria suppressed the populations of A. tumefaciens Gh1 and greatly decreased the symptoms of crown gall. Furthermore, biofilm production and motility behaviors of A. tumefaciens Gh1were greatly inhibited by the Cell-free Culture Supernatant (CFCS) of endophytic bacteria. According to our findings, CFCS may reduce the adhesion of A. tumefaciens Gh1 cells to grapevine cv. Rashe root tissues as well as their chemotaxis motility toward the extract of the roots. When compared to the untreated control, statistical analysis showed that CFCS significantly reduced the swimming, twitching, and swarming motility of A. tumefaciens Gh1. The findings demonstrated that the endophytic bacteria effectively stimulated the production of plant defensive enzymes including superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and total soluble phenols at different time intervals in grapevine inoculated with A. tumefaciens Gh1. The Ba47 strain markedly increased the expression levels of defense genes associated with plant resistance. The up-regulation of PR1, PR2, VvACO1, and GAD1 genes in grapevine leaves indicates the activation of SA and JA pathways, which play a role in enhancing resistance to pathogen invasion. The results showed that treating grapevine with Ba47 increased antioxidant defense activities and defense-related gene expression, which reduced oxidative damage caused by A. tumefaciens and decreased the incidence of crown gall disease. CONCLUSION: This is the first study on how A. tumefaciens, the grapevine crown gall agent, is affected by CFCS generated by endophytic bacteria in terms of growth and virulence features. To create safer plant disease management techniques, knowledge of the biocontrol processes mediated by CFCS during microbial interactions is crucial. | 2024 | 38336608 |
| 8114 | 8 | 0.9705 | Reductive soil disinfestation attenuates antibiotic resistance genes in greenhouse vegetable soils. Reductive soil disinfestation (RSD) is an emerging technique that ameliorates soil degradation, but its effects against antibiotic resistance genes (ARGs) were unclear. Here, we examined soil properties, ARG types and numbers, and ARG profiles, and bacterial community compositions following 4 soil treatments: control; straw addition (SA); water flooding (WF); and RSD, both straw addition and water flooding. The results showed that the numbers of ARG types and subtypes decreased by 10.8% and 21.1%, respectively, after RSD, and the numbers of ARGs decreased by 18.6%. The attenuated multidrug, beta-lactam, macrolide, and phenicol resistance genes in the RSD soil corresponded to a decreased relative abundance of ARG subtypes (i.e., adeF, mdtM, TypeB_NfxB, mecA, nalC, OXA-60, and cmlA4). Taxa in phyla Proteobacteria, Actinobacteria, and Deinococcus-Thermus were the main hosts for dominant ARG subtypes and were inhibited by RSD. The selected bacterial genera and soil properties explained 83.4% of the variance in ARG composition, suggesting that the improved soil properties and the reduced potential ARG hosts produced by the interactions of straw addition and water flooding are likely responsible for ARG attenuation by RSD. Therefore, RSD has the potential to mitigate ARG pollution in soils. | 2021 | 34293692 |
| 7073 | 9 | 0.9705 | Fecal Indicator Bacteria and Antibiotic Resistance Genes in Storm Runoff from Dairy Manure and Compost-Amended Vegetable Plots. Given the presence of antibiotics and resistant bacteria in livestock manures, it is important to identify the key pathways by which land-applied manure-derived soil amendments potentially spread resistance. The goal of this field-scale study was to identify the effects of different types of soil amendments (raw manure from cows treated with cephapirin and pirlimycin, compost from antibiotic-treated or antibiotic-free cows, or chemical fertilizer only) and crop type (lettuce [ L.] or radish [ L.]) on the transport of two antibiotic resistance genes (ARGs; 1 and ) via storm runoff from six naturally occurring storms. Concurrent quantification of sediment and fecal indicator bacteria (FIB; and enterococci) in runoff permitted comparison to traditional agricultural water quality targets that may be driving factors of ARG presence. Storm characteristics (total rainfall volume, storm duration, etc.) significantly influenced FIB concentration (two-way ANOVA, < 0.05), although both effects from individual storm events (Kruskal-Wallis, < 0.05) and vegetative cover influenced sediment levels. Composted and raw manure-amended plots both yielded significantly higher 1 and B levels in runoff for early storms, at least 8 wk following initial planting, relative to fertilizer-only or unamended barren plots. There was no significant difference between 1 or B levels in runoff from plots treated with compost derived from antibiotic-treated versus antibiotic-free dairy cattle. Our findings indicate that agricultural fields receiving manure-derived amendments release higher quantities of these two "indicator" ARGs in runoff, particularly during the early stages of the growing season, and that composting did not reduce effects of ARG loading in runoff. | 2019 | 31589689 |
| 8113 | 10 | 0.9704 | Fate of antibiotic resistance genes in mesophilic and thermophilic anaerobic digestion of chemically enhanced primary treatment (CEPT) sludge. Anaerobic digestion (AD) of chemically enhanced primary treatment (CEPT) sludge and non-CEPT (conventional sedimentation) sludge were comparatively operated under mesophilic and thermophilic conditions. The highest methane yield (692.46±0.46mL CH(4)/g VS(removed) in CEPT sludge) was observed in mesophilic AD of CEPT sludge. Meanwhile, thermophilic conditions were more favorable for the removal of total antibiotic resistance genes (ARGs). In this study, no measurable difference in the fates and removal of ARGs and class 1 integrin-integrase gene (intI1) was observed between treated non-CEPT and CEPT sludge. However, redundancy analysis indicated that shifts in bacterial community were primarily accountable for the variations in ARGs and intI1. Network analysis further revealed potential host bacteria for ARGs and intI1. | 2017 | 28797965 |
| 6053 | 11 | 0.9704 | Probiotic properties of lactic acid bacteria isolated from water-buffalo mozzarella cheese. This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of β-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the β-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development. | 2014 | 25117002 |
| 7538 | 12 | 0.9704 | Short-term thermophilic treatment cannot remove tetracycline resistance genes in pig manures but exhibits controlling effects on their accumulation and spread in soil. In this work, a microcosm experiment was conducted to merely mimic thermophilic phase in aerobic composting with pig manures in order to explore: (i) the effect of thermophilic phase in composting on the abundances of tetracycline resistance genes (TRGs); and (ii) the impacts of the treated manures on the abundances of TRGs in soil. It was found that 4days of thermophilic process reduced the abundance of TRGs in pig manures by ∼1 lg unit compared to the samples without treatments, suggesting that other phases in composting may play significant roles in removal of TRGs. Once pig manures with thermophilic treatment were applied to soil, TRGs abundances decreased to the levels in unfertilized soil. With correlation analyses, it was concluded that pig manure derived tetracycline-resistant bacteria (TRB) and nutrients exerted different effects on TRGs abundances in soil. In conclusion, short-term thermophilic treatment cannot remove tetracycline resistance genes in pig manures but exhibits controlling effects on their accumulation and spread in soil. Nutrients enrichment in soil following manuring of treated pig manures, together with a large proportion of gram-positive TRB left in treated pig manures with less risk to TRGs spread, contributed to the controlling effects. | 2017 | 28715744 |
| 8782 | 13 | 0.9703 | Antagonistic bacterium Bacillus amyloliquefaciens induces resistance and controls the bacterial wilt of tomato. BACKGROUND: Bacterial wilt caused by Ralstonia solanacearum (RS) is a serious threat for agricultural production. In this study, Bacillus amyloliquefaciens strains CM-2 and T-5 antagonistic to RS were used to create bioorganic fertilisers to control tomato wilt under greenhouse conditions. The possible mechanism of resistance inducement by the antagonistic bacteria was also evaluated. RESULTS: The application of bioorganic fertilisers significantly reduced incidences of tomato wilt (by 63-74%), promoted plant growth and significantly reduced the RS populations in rhizosphere compared with the control. Both strains CM-2 and T-5 applied with bioorganic fertilisers survived well in the tomato rhizosphere. Tomato seedlings treated with cell suspension of T-5 followed by challenge inoculation with RS increased the activities of polyphenol oxidase, phenylalanine ammonia lyase and peroxidase compared with the untreated control. Furthermore, the expressions of the marker genes responsible for synthesis of phytohormones salicylic acid, ethylene and jasmonic acid in seedlings treated with T-5 in response to inoculated pathogen were significantly higher. CONCLUSIONS: This study suggests that strains CM-2 and T-5 containing bioorganic fertilisers effectively control tomato wilt. Increased enzyme activities and expression of defence genes in plants indicated that the antagonistic bacteria induced plant resistance, which was the potential biocontrol mechanism of tomato wilt. | 2013 | 23519834 |
| 7535 | 14 | 0.9703 | The effects of pig manure application on the spread of tetracycline resistance in bulk and cucumber rhizosphere soils: a greenhouse experiment. It is important to understand the dynamics of tetracycline-resistant bacteria (TRB) and tetracycline resistance genes (TRGs) in bulk and rhizosphere soils for evaluating the spread of TRGs from pig manure to human. In this work, a greenhouse experiment was conducted to investigate the difference in abundance of TRB, tetracycline-resistant Escherichia coli (TRE), tetracycline-resistant Pseudomonas spp. (TRP), and TRGs between bulk and cucumber rhizosphere soils. The application of pig manure resulted in the long-term persistence of TRB, TRE, TRP, and TRGs in bulk soil and rhizosphere of cucumber for at least 65 days. Pig manure application dose was the major driving force in altering the abundances of TRB and TRE, whereas TRP was disturbed mainly by compartment (bulk soil or rhizosphere). Both TRE and the percentage of TRE in bulk and rhizosphere soils increased linearly with an increase in dose of pig manure. The exponential relationships between pig manure dose and TRP along with TRP percentage were also noted. There were significant differences in the relative abundances of TRGs between bulk and cucumber rhizosphere soils, suggesting the use of pig manure exerted a more lasting impact on the spread of TRGs in the rhizosphere than in the bulk soil. | 2017 | 28222270 |
| 8117 | 15 | 0.9703 | Composting of oxytetracycline fermentation residue in combination with hydrothermal pretreatment for reducing antibiotic resistance genes enrichment. Hydrothermal pretreatment can efficiently remove the residual antibiotics in oxytetracycline fermentation residue (OFR), but its effect on antibiotic resistance genes (ARGs) during composting remains unclear. This study compared the shifts in bacterial community and evolutions in ARGs and integrons during different composting processes of OFRs with and without hydrothermal pretreatment. The results demonstrated that hydrothermal pretreatment increased the bacterial alpha diversity at the initial phase, and increased the relative abundances of Proteobacteria and Actinobacteria but decreased that of Bacteroidetes at the final phase by inactivating mycelia and removing residual oxytetracycline. Composting process inevitably elevated the abundance and relative abundance of ARGs. However, the increase in ARGs was significantly reduced by hydrothermal pretreatment, because the removal of oxytetracycline decreased their potential host bacteria and inhibited their horizontal gene transfer. The results demonstrated that hydrothermal pretreatment is an efficient strategy to reduce the enrichment of ARGs during the OFR composting. | 2020 | 33099099 |
| 19 | 16 | 0.9703 | Strengthening Grapevine Resistance by Pseudomonas fluorescens PTA-CT2 Relies on Distinct Defense Pathways in Susceptible and Partially Resistant Genotypes to Downy Mildew and Gray Mold Diseases. Downy mildew caused by the oomycete Plasmopara viticola and gray mold caused by the fungus Botrytis cinerea are among the highly threatening diseases in vineyards. The current strategy to control these diseases relies totally on the application of fungicides. The use of beneficial microbes is arising as a sustainable strategy in controlling various diseases. This can be achieved through the activation of the plants' own immune system, known as induced systemic resistance (ISR). We previously showed that bacteria-mediated ISR in grapevine involves activation of both immune response and priming state upon B. cinerea challenge. However, the effectiveness of beneficial bacteria against the oomycete P. viticola remains unknown, and mechanisms underpinning ISR against pathogens with different lifestyles need to be deciphered. In this study, we focused on the capacity of Pseudomonas fluorescens PTA-CT2 to induce ISR in grapevine against P. viticola and B. cinerea by using two grafted cultivars differing in their susceptibility to downy mildew, Pinot noir as susceptible and Solaris as partially resistant. On the basis of their contrasting phenotypes, we explored mechanisms underlying ISR before and upon pathogen infection. Our results provide evidence that in the absence of pathogen infection, PTA-CT2 does not elicit any consistent change of basal defenses, while it affects hormonal status and enhances photosynthetic efficiency in both genotypes. PTA-CT2 also induces ISR against P. viticola and B. cinerea by priming common and distinct defensive pathways. After P. viticola challenge, PTA-CT2 primes salicylic acid (SA)- and hypersensitive response (HR)-related genes in Solaris, but SA and abscisic acid (ABA) accumulation in Pinot noir. However, ISR against B. cinerea was associated with potentiated ethylene signaling in Pinot noir, but with primed expression of jasmonic acid (JA)- and SA-responsive genes in Solaris, together with downregulation of HR-related gene and accumulation of ABA and phytoalexins. | 2019 | 31620150 |
| 8118 | 17 | 0.9702 | Effects of biocontrol Bacillus and fermentation bacteria additions on the microbial community, functions and antibiotic resistance genes of prickly ash seed oil meal-biochar compost. This study evaluated the effects of biocontrol Bacillus and fermenting bacteria addition on the microbial community, metabolic functions and antibiotic resistance genes (ARGs) of new prickly ash seed oil meal (PSOM)-biochar composting. The results showed that the addition of Bacillus subtilis and fermentation bacteria significantly increased the NH(4)(+)-N, bacterial abundance and fungal diversity of compost while decreasing the relative abundances (RAs) of carbon metabolism genes in mature compost. NH(4)(+)-N was significantly correlated with microbial abundance and diversity, and its increase was closely related to microbial amino acid metabolism. The addition of biocontrol and fermenting bacteria changed the RAs of ARGs, which was caused by changes in the potential hosts Proteobacteria, Bacteroidota and Firmicutes in the compost. Consequently, adding Bacillus and fermenting bacteria into PSOM to make composting was suggested as an effective method to promote nutrient transformation, regulate microbial activity and decrease RAs of tetracycline and vancomycin ARGs. | 2021 | 34339999 |
| 3838 | 18 | 0.9702 | The In-Feed Antibiotic Carbadox Induces Phage Gene Transcription in the Swine Gut Microbiome. Carbadox is a quinoxaline-di-N-oxide antibiotic fed to over 40% of young pigs in the United States that has been shown to induce phage DNA transduction in vitro; however, the effects of carbadox on swine microbiome functions are poorly understood. We investigated the in vivo longitudinal effects of carbadox on swine gut microbial gene expression (fecal metatranscriptome) and phage population dynamics (fecal dsDNA viromes). Microbial metagenome, transcriptome, and virome sequences were annotated for taxonomic inference and gene function by using FIGfam (isofunctional homolog sequences) and SEED subsystems databases. When the beta diversities of microbial FIGfam annotations were compared, the control and carbadox communities were distinct 2 days after carbadox introduction. This effect was driven by carbadox-associated lower expression of FIGfams (n = 66) related to microbial respiration, carbohydrate utilization, and RNA metabolism (q < 0.1), suggesting bacteriostatic or bactericidal effects within certain populations. Interestingly, carbadox treatment caused greater expression of FIGfams related to all stages of the phage lytic cycle 2 days following the introduction of carbadox (q ≤0.07), suggesting the carbadox-mediated induction of prophages and phage DNA recombination. These effects were diminished by 7 days of continuous carbadox in the feed, suggesting an acute impact. Additionally, the viromes included a few genes that encoded resistance to tetracycline, aminoglycoside, and beta-lactam antibiotics but these did not change in frequency over time or with treatment. The results show decreased bacterial growth and metabolism, prophage induction, and potential transduction of bacterial fitness genes in swine gut bacterial communities as a result of carbadox administration.IMPORTANCE FDA regulations on agricultural antibiotic use have focused on antibiotics that are important for human medicine. Carbadox is an antibiotic not used in humans but frequently used on U.S. pig farms. It is important to study possible side effects of carbadox use because it has been shown to promote bacterial evolution, which could indirectly impact antibiotic resistance in bacteria of clinical importance. Interestingly, the present study shows greater prophage gene expression in feces from carbadox-fed animals than in feces from nonmedicated animals 2 days after the initiation of in-feed carbadox treatment. Importantly, the phage genetic material isolated in this study contained genes that could provide resistance to antibiotics that are important in human medicine, indicating that human-relevant antibiotic resistance genes are mobile between bacteria via phages. This study highlights the collateral effects of antibiotics and demonstrates the need to consider diverse antibiotic effects whenever antibiotics are being used or new regulations are considered. | 2017 | 28790203 |
| 7748 | 19 | 0.9701 | Bacillus subtilis reduces antibiotic resistance genes of animal sludge in vermicomposting by improving heat stress tolerance of Eisenia foetida and bacterial community adjustment. Antibiotic resistance genes (ARGs) in livestock industry have been recognized as a kind of pollutant. The effect of Bacillus subtilis (B. subtilis) as an additive for the reduction of ARGs in animal sludge from livestock and poultry wastewater treatment plant during vermicomposting was investigated. We also evaluated the oxidative stress level and growth of earthworms, Eisenia foetida, bacterial community succession, and the quality of the end products. Two treatments were conducted using B. subtilis, one at 18 °C and another at 28 °C. Controls were setup without the bacteria. The results showed that inoculation of B. subtilis promoted the degradation of organics at 28 °C and increased the germination index to 236%. The increased activities of the superoxide dismutase (1.69 U/mg pr) and catalase (8.05 U/mg pr) and the decreased activity of malondialdehyde (0.02 nmol/mg pr) by B. subtilis at 28 °C showed that the earthworms were relieved of heat stress. The addition of B. subtilis reduced the abundance of 32 target ARGs, including integron (intI-1), transposase (IS613) and resistant genes, such as sulfonamide (sul2), quinolone (oprJ), macrolide-lincosamide-streptogramin group B (ermF, ermB), tetracycline (tetL-02, tetX), β-lactama (blaOXA10-01) and aminoglycoside [strB, aac(6')-Ib(aka aacA4)-01, aac(6')-Ib(aka aacA4)-02]. Organic matter degrading Membranicola, Paludisphaera, Sphingorhabdus and uncultured bacterium belonging to the order Chitinophagales, nitrifying and nitrogen-fixing Singulisphaera and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, soil remediating Achromobacter, and plant growth promoting Kaistia, Galbibacter and Ilumatobacter were increased significantly (P < 0.05). However, the growth of harmful bacteria such as Burkholderiaceae was inhibited in the vermicompost. In earthworm guts, the probiotic Mesorhizobium was promoted, while the pathogenic uncultured bacterium belonging to the family Enterobacteriaceae was reduced. Besides, B. subtilis enhanced the host relationships between bacteria and ARGs. These findings might be helpful in the removal of ARGs in animal wastes and in understanding the synergy between earthworms and microorganisms. | 2023 | 36529325 |