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Current Microbiology Apr 2021The increased prevalence of multidrug-resistant pathogens poses a significant clinical threat, and hence, the discovery of novel antibiotics is the need of the hour....
The increased prevalence of multidrug-resistant pathogens poses a significant clinical threat, and hence, the discovery of novel antibiotics is the need of the hour. Several attempts are being made worldwide to screen and identify newer antibiotics from various microbial sources. The genus Paenibacillus is known for its biosynthetic potential and metabolic versatility in producing several secondary metabolites. In this study, we isolated Paenibacillus alvei strain JR949 from the soil, which exhibited antimicrobial activity against Enteropathogenic Escherichia coli (EPEC), Pseudomonas aeruginosa (PAO1), and methicillin-resistant Staphylococcus aureus (MRSA). The whole genome of this strain was sequenced using the Illumina platform. The genome mining of the draft genome sequence revealed a total of 31 biological gene clusters (BGCs) responsible for the synthesis of secondary metabolites. The construction of the similarity network of the BGCs and the comparative analysis with the genetically related strains aided the identification of metabolites produced by this strain. We identified BGCs coding for paenibactin, paenibacterin, anabaenopeptin NZ857, icosalide A/B, polymyxin, and bicornutinA1/A2 with 100% similarity. The BGCs with lower sequence similarity to paenibacterin, polymyxin B, colistin A/B, pellasoren, tridecaptin, pelgipeptin, and marthiapeptide were also identified. Furthermore, 13 putative NRPS BGCs, 3 NRPS-T1PKS hybrid clusters, a T1PKS, and a bacteriocin BGC were identified with very low similarity (≤ 25%) or no similarity with known antibiotics. Further experimental investigations may result in the discovery of novel antimicrobial drugs.
Topics: Anti-Infective Agents; Methicillin-Resistant Staphylococcus aureus; Multigene Family; Paenibacillus; Sequence Analysis
PubMed: 33616690
DOI: 10.1007/s00284-021-02393-0 -
Journal of Applied Microbiology Sep 2021This research investigated the influence of soil microbiota on Escherichia coli O157:H7 survival in soil rinse and artificial soil. Additionally, the influence of...
AIMS
This research investigated the influence of soil microbiota on Escherichia coli O157:H7 survival in soil rinse and artificial soil. Additionally, the influence of selected soil bacteria on E. coli O157:H7 in soil environments was determined.
METHODS AND RESULTS
Escherichia coli O157:H7 counts (log CFU per ml or g ) were determined by spread plating: (i) artificial soil amended with soil rinse (filter-sterilized and unfiltered) at 30°C; (ii) unfiltered soil rinse (50 ml) treated with cycloheximide (200 μg ml ), vancomycin (40 μg ml ), heat (80°C, 15 min) and no treatment (control) for 7 days at 30°C and (iii) filtered soil rinse with selected soil bacterial isolates over 7 days. There was a significant difference (P = 0·027) in E. coli O157:H7 counts after 35 days between artificial soils amended with filtered (4·45 ± 0·29) and non-filtered (1·83 ± 0·33) soil rinse. There were significant differences (P < 0·05) in E. coli O157:H7 counts after 3 days of incubation between soil rinse treatments (heat (7·04 ± 0·03), cycloheximide (6·94 ± 0·05), vancomycin (4·26 ± 0·98) and control (5·00 ± 0·93)). Lastly, a significant difference (P < 0·05) in E. coli O157:H7 counts was observed after 3 days of incubation at 30°C in filtered soil rinse when incubated with Paenibacillus alvei versus other soil bacterial isolates evaluated.
CONCLUSIONS
Soil microbiota isolated from Florida sandy soil influenced E. coli O157:H7 survival. Specifically, P. alvei reduced E. coli O157:H7 by over 3 log CFU per ml after 3 days of incubation at 30°C in filtered soil rinse.
SIGNIFICANCE AND IMPACT OF THE STUDY
This research identified soil bacterial isolates that may reduce E. coli O157:H7 in the soil environment and be used in future biocontrol applications.
Topics: Antibiosis; Biological Control Agents; Colony Count, Microbial; Escherichia coli O157; Florida; Food Microbiology; Paenibacillus; Soil; Soil Microbiology
PubMed: 33583119
DOI: 10.1111/jam.15039 -
Plants (Basel, Switzerland) Jan 2021In the last two decades grapevine trunk diseases (GTDs) have emerged as the most significant threat for grapevine sustainability worldwide. The tracheomycotic fungus...
In the last two decades grapevine trunk diseases (GTDs) have emerged as the most significant threat for grapevine sustainability worldwide. The tracheomycotic fungus (Pch) is the predominant GTD-associated species and cannot be controlled with available chemicals. In the present study, we evaluated the effectiveness of two microbial strains ( K165 and F2) against Pch in grapevine. In vitro bioassays, performed in a growth culture medium simulating the xylem environment, indicated that F2 decreased Pch growth and sporulation, whereas K165 did not have any effect on Pch growth. experiments revealed that root-drench and stem-puncture application of K165 and F2 reduced the endophytic relative DNA amount of Pch by 90% and 82%, respectively, compared to controls. However, wood discoloration, the typical symptom of Pch infection, was not reduced in the F2 treated grapevines. Nevertheless, the F2 treated grapevines harbored higher lignin levels compared to mocks, as it was also done by K165. Therefore, F2 and K165 have the potential to be used as biocontrol agents against Pch in grapevines.
PubMed: 33499084
DOI: 10.3390/plants10020207 -
The Science of the Total Environment Dec 2020The pesticides belonging the strobilurin group are among the most common contaminants in the environment. In this work, biodegradation studies of the strobilurin...
The pesticides belonging the strobilurin group are among the most common contaminants in the environment. In this work, biodegradation studies of the strobilurin fungicide Pyraclostrobin by bacteria from orange cultivation plots were performed aiming to contribute with the development of a bioremediation method. Experiments were performed in triplicate with validated methods, and optimization was performed by Central Composite Design and Response Surface Methodology. The strains were evaluated in liquid nutrient medium containing 100 mg L of Pyraclostrobin, and decreased concentrations of 61.5 to 100.5 mg L were determined after 5 days at 37 °C and 130 rpm, showing the importance of strain selection. When the five most efficient strains (Bacillus sp. CSA-13, Paenibacillus alvei CBMAI2221, Bacillus sp. CBMAI2222, Bacillus safensis CBMAI2220 and Bacillus aryabhattai CBMAI2223) were used in consortia, synergistic and antagonistic effects were observed accordingly to the employed combination of bacteria, resulting in 64.2 ± 3.9 to 95.4 ± 4.9 mg L residual Pyraclostrobin. In addition, the formation of 1-(4-chlorophenyl)-1H-pyrazol-3-ol was quantified (0.59-0.01 mg L), and a new biodegradation pathway was proposed with 15 identified metabolites. Experiments were also performed in soil under controlled conditions (30 °C, 0-28 days, 100 mg kg pesticide), and the native microbiome reduced the pesticide concentration to 70.4 ± 2.3 mg L, whereas the inoculation of an efficient bacterial consortium promoted clearly better results, 57.2 ± 3.9 mg L residual Pyraclostrobin. This suggests that the introduction of these strains in soil in a bioaugmentation process increases decontamination. However, the native microbiome is important for a more efficient bioremediation.
Topics: Bacillus; Bacteria; Biodegradation, Environmental; Citrus sinensis; Fungicides, Industrial; Paenibacillus; Soil Microbiology; Soil Pollutants; Strobilurins
PubMed: 32763599
DOI: 10.1016/j.scitotenv.2020.140968 -
BMC Research Notes Jun 2020A Paenibacillus strain isolated in previous research exhibited antimicrobial activity against relevant human pathogens including Staphylococcus aureus and Listeria...
OBJECTIVE
A Paenibacillus strain isolated in previous research exhibited antimicrobial activity against relevant human pathogens including Staphylococcus aureus and Listeria monocytogenes. In this study, the genome of the aforementioned strain, designated as MP1, was shotgun sequenced. The draft genome of strain MP1 was subject to multiple genomic analyses to taxonomically characterize it and identify the genes potentially responsible for its antimicrobial activity.
RESULTS
Here we report the draft genome sequence of an antimicrobial producing Paenibacillus strain, MP1. Average Nucleotide Identity (ANI) analysis established strain MP1 as a new strain of the previously characterized Paenibacillus alvei. The genomic analysis identified several putative secondary metabolite clusters including seven Nonribosomal Peptide Synthetase clusters (NRPS) (> 10,000 nt), one bacteriocin or other unspecified Ribosomally Synthesized and Post-Translationally modified Peptide Product (RiPP), one lanthipeptide, and six hybrid clusters (NRPS-Type I Polyketide synthase (T1PKS) and NRPS-trans Amino Transferase Polyketide Synthase (AT-PKS)).
Topics: Anti-Infective Agents; Genome, Bacterial; Paenibacillus; Whole Genome Sequencing
PubMed: 32517793
DOI: 10.1186/s13104-020-05124-z -
Virulence Dec 2020is a bacterial pathogen that causes epidemic outbreaks of European foulbrood (EFB) in honey bee populations. The pathogenicity of a bacterium depends on its virulence,...
is a bacterial pathogen that causes epidemic outbreaks of European foulbrood (EFB) in honey bee populations. The pathogenicity of a bacterium depends on its virulence, and understanding the mechanisms influencing virulence may allow for improved disease control and containment. Using a standardized assay, we demonstrate that virulence varies greatly among sixteen isolates from five European countries. Additionally, we explore the causes of this variation. In this study, virulence was independent of the multilocus sequence type of the tested pathogen, and was not affected by experimental co-infection with , a bacterium often associated with EFB outbreaks. Virulence was correlated with the growth dynamics of isolates in artificial medium, and with the presence of a plasmid carrying a gene coding for the putative toxin melissotoxin A. Our results suggest that some strains showed an increased virulence due to the acquisition of a toxin-carrying mobile genetic element. We discuss whether strains with increased virulence play a role in recent EFB outbreaks.
Topics: Animals; Bacterial Toxins; Bacterial Typing Techniques; Bees; Enterococcaceae; Gram-Positive Bacterial Infections; Interspersed Repetitive Sequences; Larva; Multilocus Sequence Typing; Plasmids; Virulence
PubMed: 32456539
DOI: 10.1080/21505594.2020.1768338 -
Metabolites May 2020Plant growth-promoting rhizobacteria (PGPR) are beneficial microbes in the rhizosphere that can directly or indirectly stimulate plant growth. In addition, some can...
Plant growth-promoting rhizobacteria (PGPR) are beneficial microbes in the rhizosphere that can directly or indirectly stimulate plant growth. In addition, some can prime plants for enhanced defense against a broad range of pathogens and insect herbivores. In this study, four PGPR strains ( N04, N19, T19, and T22) were used to induce priming in (cv. Moneymaker) plants. Plants were inoculated with each of the four PGPRs, and plant tissues (roots, stems, and leaves) were harvested at 24 h and 48 h post-inoculation. Methanol-extracted metabolites were analyzed by ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS). Chemometric methods were applied to mine the data and characterize the differential metabolic profiles induced by the PGPR. The results revealed that all four strains induced defense-related metabolic reprogramming in the plants, characterized by dynamic changes to the metabolomes involving hydroxycinnamates, benzoates, flavonoids, and glycoalkaloids. In addition, targeted analysis of aromatic amino acids indicated differential quantitative increases or decreases over a two-day period in response to the four PGPR strains. The metabolic alterations point to an altered or preconditioned state that renders the plants primed for enhanced defense responses. The results contribute to ongoing efforts in investigating and unraveling the biochemical processes that define the PGPR priming phenomenon.
PubMed: 32443694
DOI: 10.3390/metabo10050210 -
Pathogens (Basel, Switzerland) Apr 2020An emerging need for new classes of antibiotics is, on the one hand, evident as antimicrobial resistance continues to rise. On the other hand, the awareness of the pros...
An emerging need for new classes of antibiotics is, on the one hand, evident as antimicrobial resistance continues to rise. On the other hand, the awareness of the pros and cons of chemically synthesized compounds' extensive use leads to a search for new metabolites in already known reservoirs. Previous research showed that strain ( MP1) recovered from a buckwheat honey sample presented a wide spectrum of antimicrobial activity against both Gram-positive and Gram-negative pathogens. Recent investigation has confirmed that MP1 (deposited at DDBJ/ENA/GenBank under the accession WSQB00000000) produces a proteinaceous, heat-stable compound(s) with the maximum antimicrobial production obtained after 18 hours of MP1 growth in LB medium at 37 °C with continuous shaking at 200 RPM. The highest activity was found in the 40% ammonium sulfate precipitate, with high activity also remaining in the 50% and 60% ammonium sulfate precipitates. Moderate to high antimicrobial activity that is insensitive to proteases or heat treatment, was confirmed against pathogenic bacteria that included FSL - X1-0001 (strain 10403S), L1 - 0030 and O157: H7. Further studies, including de novo sequencing of peptides by mass spectrometry, are in progress.
PubMed: 32344843
DOI: 10.3390/pathogens9050319 -
Metabolites Sep 2019Priming is a natural phenomenon that pre-conditions plants for enhanced defence against a wide range of pathogens. It represents a complementary strategy, or sustainable...
Priming is a natural phenomenon that pre-conditions plants for enhanced defence against a wide range of pathogens. It represents a complementary strategy, or sustainable alternative that can provide protection against disease. However, a comprehensive functional and mechanistic understanding of the various layers of priming events is still limited. A non-targeted metabolomics approach was used to investigate metabolic changes in plant growth-promoting rhizobacteria (PGPR)-primed seedlings infected with the anthracnose-causing fungal pathogen, , with a focus on the post-challenge primed state phase. At the 4-leaf growth stage, the plants were treated with a strain of at 10 cfu mL. Following a 24 h PGPR application, the plants were inoculated with a spore suspension (10 spores mL), and the infection monitored over time: 1, 3, 5, 7 and 9 days post-inoculation. Non-infected plants served as negative controls. Intracellular metabolites from both inoculated and non-inoculated plants were extracted with 80% methanol-water. The extracts were chromatographically and spectrometrically analysed on an ultra-high performance liquid chromatography (UHPLC) system coupled to high-definition mass spectrometry. The acquired multidimensional data were processed to create data matrices for chemometric modelling. The computed models indicated time-related metabolic perturbations that reflect primed responses to the fungal infection. Evaluation of orthogonal projection to latent structure-discriminant analysis (OPLS-DA) loading shared and unique structures (SUS)-plots uncovered the differential stronger defence responses against the fungal infection observed in primed plants. These involved enhanced levels of amino acids (tyrosine, tryptophan), phytohormones (jasmonic acid and salicylic acid conjugates, and zeatin), and defence-related components of the lipidome. Furthermore, other defence responses in both naïve and primed plants were characterised by a complex mobilisation of phenolic compounds and biosynthesis of the flavones, apigenin and luteolin and the 3-deoxyanthocyanidin phytoalexins, apigeninidin and luteolinidin, as well as some related conjugates.
PubMed: 31547091
DOI: 10.3390/metabo9100194 -
Metabolites Jul 2019Metabolic changes in sorghum seedlings in response to (NAS-6G6)-induced systemic resistance against crown rot were investigated by means of untargeted ultra-high...
Metabolic changes in sorghum seedlings in response to (NAS-6G6)-induced systemic resistance against crown rot were investigated by means of untargeted ultra-high performance liquid chromatography-high definition mass spectrometry (UHPLC-HDMS). Treatment of seedlings with the plant growth-promoting rhizobacterium at a concentration of 1 × 10 colony forming units mL prior to inoculation with lowered crown rot disease severity significantly at the highest inoculum dose of 1 × 10 spores mL. Intracellular metabolites were subsequently methanol-extracted from treated and untreated sorghum roots, stems and leaves at 1, 4 and 7 days post inoculation (d.p.i.) with . The extracts were analysed on an UHPLC-HDMS platform, and the data chemometrically processed to determine metabolic profiles and signatures related to priming and induced resistance. Significant treatment-related differences in primary and secondary metabolism post inoculation with were observed between -primed versus naïve seedlings. The differential metabolic reprogramming in primed plants comprised of a quicker and/or enhanced upregulation of amino acid-, phytohormone-, phenylpropanoid-, flavonoid- and lipid metabolites in response to inoculation with .
PubMed: 31340428
DOI: 10.3390/metabo9070150