-
ISME Communications Sep 2023Food safety of leafy greens is an emerging public health issue as they can harbor opportunistic human pathogens (OHPs) and expose OHPs to consumers. Protists are an...
Food safety of leafy greens is an emerging public health issue as they can harbor opportunistic human pathogens (OHPs) and expose OHPs to consumers. Protists are an integral part of phyllosphere microbial ecosystems. However, our understanding of protist-pathogen associations in the phyllosphere and their consequences on public health remains poor. Here, we examined phyllosphere protists, human pathogen marker genes (HPMGs), and protist endosymbionts from four species of leafy greens from major supermarkets in Xiamen, China. Our results showed that Staphylococcus aureus and Klebsiella pneumoniae were the dominant human pathogens in the vegetable phyllosphere. The distribution of HPMGs and protistan communities differed between vegetable species, of which Chinese chive possessed the most diverse protists and highest abundance of HPMGs. HPMGs abundance positively correlated with the diversity and relative abundance of phagotrophic protists. Whole genome sequencing further uncovered that most isolated phyllosphere protists harbored multiple OHPs which carried antibiotic resistance genes, virulence factors, and metal resistance genes and had the potential to HGT. Colpoda were identified as key phagotrophic protists which positively linked to OHPs and carried diverse resistance and virulence potential endosymbiont OHPs including Pseudomonas nitroreducens, Achromobacter xylosoxidans, and Stenotrophomonas maltophilia. We highlight that phyllosphere protists contribute to the transmission of resistant OHPs through internalization and thus pose risks to the food safety of leafy greens and human health. Our study provides insights into the protist-OHP interactions in the phyllosphere, which will help in food safety surveillance and human health.
PubMed: 37660098
DOI: 10.1038/s43705-023-00302-z -
Molecular Plant-microbe Interactions :... Apr 2022
Topics: Acyl-Butyrolactones; Pseudomonas; Quorum Sensing
PubMed: 35285671
DOI: 10.1094/MPMI-12-21-0310-A -
Journal of Environmental Science and... 2023Sheath blight () causes significant yield losses in rice ( L.). Its sustainable management needs an efficient biocontrol agent. The objective was to screen bacterial...
Sheath blight () causes significant yield losses in rice ( L.). Its sustainable management needs an efficient biocontrol agent. The objective was to screen bacterial isolates as an antagonist to and identify the most efficient ones as sheath blight suppressors under greenhouse conditions. Two assays (E1 and E2) were performed in a completely randomized design with three replications. E1 tested 21 bacterial isolates antagonists to . E2 was conducted under greenhouse conditions, with rice cultivar BRS Pampeira sown in plastic pots (7 kg) containing fertilized soil. Sixty old plants were inoculated with a segment of a toothpick containing fragments of , followed by spray inoculation of a bacterial suspension (10 CFU/mL). The severity of the disease was determined by calculating the relative lesion size formed on the colm. Isolates BRM32112 (), BRM65929 (), and BRM65919 () reduced colony radial growth by 92.8, 77.56, and 75.56%, respectively while BRM63523 (), BRM65923 and BRM65916 () and BRM65919 () with 23.45, 23.37, 23.62, and 20.17 cm, respectively were effective at suppressing sheath blight in greenhouse, indicating their potential as a biofungicide for sheath blight suppression.
Topics: Oryza; Plant Diseases; Rhizoctonia; Pest Control, Biological
PubMed: 37313602
DOI: 10.1080/03601234.2023.2220644 -
Biotechnology Reports (Amsterdam,... Dec 2021The mechanisms of tolerance to heavy metals used by some microorganisms identified by bioprospection processes are useful for the development and implementation of...
The mechanisms of tolerance to heavy metals used by some microorganisms identified by bioprospection processes are useful for the development and implementation of bioremediation strategies for contaminated environments with high toxic load caused by heavy metals. A total of seven native microbial isolates were obtained from wastewater bodies from an industrial zone in the municipality of Girardota, Antioquia, Colombia. Subsequently, they were selected to evaluate their lead tolerance capacity at different concentrations. In addition, some parameters were determined, such as the capacity to produce exopolysaccharides and their biosorption to understand potential mechanisms associated to lead tolerance. According to the biocehemical test (Vitek) and the molecular analysis of sequences of 16S rDNA, bacterial were identified as , and . We determined that the seven isolates had the capacity to tolerate concentrations higher than 50 mg/ml of lead, and that the concentration and exposure time (40 h) to this metal significantly affect the spp. isolates. Statistically significant differences were detected ( < 0.05) in the production of the exopolysaccharide (EPS) among the isolates. (P16) was the strain with the maximum absorbance exopolysaccharide measured. We evidenced that (P14) and (P20) have 80% capacity to biosorber lead using live mass (minimum range from 80.9% to 87%). It is suggested that the tolerance to lead exhibited by the environmental isolates of spp. can be attributed to the production of exopolysaccharides and biosorption, which are protection factors for its survival in contaminated places. Finally, it was determined that the adsorption measured from dead biomass was significant ( < 0.05) from 40 h of exposure to metal (Average 182.2 ± 7). We generated new knowledge about the potential use of the spp. genus to bioremediate affluent contaminated with heavy metals.
PubMed: 34765463
DOI: 10.1016/j.btre.2021.e00685 -
Bioresource Technology Dec 2020
Corrigendum to 'Rapid degradation of the organophosphate pesticide - Chlorpyrifos by a novel strain of pseudomonas nitroreducens AR-3', [Bioresource Technology 292 (2019) 122025].
PubMed: 32919286
DOI: 10.1016/j.biortech.2020.124093 -
BMC Infectious Diseases Feb 2024Pseudomonas nitroreducens is a non-fermenting, gram-negative, rod-shaped bacterium commonly inhabiting soil, particularly soil contaminated with oil brine. To our...
BACKGROUND
Pseudomonas nitroreducens is a non-fermenting, gram-negative, rod-shaped bacterium commonly inhabiting soil, particularly soil contaminated with oil brine. To our knowledge, no cases of human infection with P. nitroreducens have been previously reported. Here, we present the first documented case of cholangitis caused by P. nitroreducens in a patient with bacteremia.
CASE PRESENTATION
A 46-year-old Japanese man with an advanced pancreatic neuroendocrine tumor was hospitalized with fever and chills. Four days before admission, the patient developed right upper abdominal pain. Two days later, he also experienced fever and chills. Endoscopic retrograde cholangiopancreatography was performed on the day of admission, and the patient was diagnosed as having cholangitis associated with stent dysfunction. Gram-negative rods were isolated from blood cultures, but attempts to identify the bacteria using VITEK2 and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with VITEK MS ver. 4.7.1 (bioMérieux Japan Co. Ltd., Tokyo, Japan) were unsuccessful. Finally, the organism was identified as P. nitroreducens using MALDI-TOF MS with a MALDI Biotyper (Bruker Daltonics Co., Ltd., Billerica, MA, USA) and 16 S ribosomal RNA sequencing. Despite thorough interviews with the patient, he denied any exposure to contaminated soil. The patient was treated with intravenous cefepime and oral ciprofloxacin for 16 days based on susceptibility results, achieving a good therapeutic outcome. At the outpatient follow-up on day 28, the patient was in good general condition.
CONCLUSIONS
This is the first reported human case of cholangitis with bloodstream infection caused by P. nitroreducens. This report provides clinicians with novel insights into the clinical manifestations and diagnostic methods necessary for the accurate diagnosis of P. nitroreducens, along with guidance on treatment.
Topics: Male; Humans; Middle Aged; Neuroendocrine Tumors; Bacteremia; Bacteria; Pseudomonas; Bacteria, Aerobic; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Cholangitis; Soil; Pancreatic Neoplasms
PubMed: 38336644
DOI: 10.1186/s12879-024-09092-8 -
Bioresource Technology Nov 2020The main aim of this work was to study the allethrin binding interactions with esterase and its bioremediation potential using an isolated bacterial strain CW7,...
The main aim of this work was to study the allethrin binding interactions with esterase and its bioremediation potential using an isolated bacterial strain CW7, identified as Pseudomonas nitroreducens. The degradation conditions with strain CW7 were optimized using response surface methodology at pH 7.0, a temperature of 32 °C, and an inocula concentration of 150 mg·L, with 96% allethrin degradation observed over 7 days. The kinetic parameters q, K and K were calculated to be 0.512 day, 4.97 mg·L and 317.13 mg·L, respectively. Nine intermediate metabolites were identified after analysing the degradation products by gas chromatography-mass spectrometry. Strain CW7 effectively degraded a wide variety of pyrethroids as a carbon source. Molecular modeling, docking, and enzyme kinetics were used to investigate the binding pocket of the esterase containing amino acids such as alanine, arginine, valine, proline, cysteine, glycine, isoleucine, phenylalanine, serine, asparagine, and threonine, which play active roles in allethrin degradation.
Topics: Alanine; Allethrins; Arginine; Biodegradation, Environmental; Esterases; Glutamates; Histidine; Leucine; Lysine; Methionine; Pseudomonas; Serine; Tyrosine
PubMed: 32707504
DOI: 10.1016/j.biortech.2020.123845 -
International Journal of Molecular... Nov 2022The B12-producing strains DSM 1650 and sp. CCUG 2519 (both formerly ), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are...
The B12-producing strains DSM 1650 and sp. CCUG 2519 (both formerly ), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are promising recombinant hosts for the endogenous production of B12 precursor betaine by direct methylation of bioavailable glycine or non-proteinogenic -alanine. Two plasmid-based de novo betaine pathways, distinguished by their enzymes, have provided an expression of the genes encoding for -methyltransferases of the halotolerant cyanobacterium or plant to synthesize the internal glycine betaine or -alanine betaine, respectively. These betaines equally allowed the recombinant pseudomonads to grow effectively and to synthesize a high level of cobalamin, as well as to increase their protective properties against abiotic stresses to a degree comparable with the supplementation of an exogenous betaine. Both de novo betaine pathways significantly enforced the protection of bacterial cells against lowering temperature to 15 °C and increasing salinity to 400 mM of NaCl. However, the expression of the single plant-derived gene for the -alanine-specific -methyltransferase additionally increased the effectiveness of exogenous glycine betaine almost twofold on cobalamin biosynthesis, probably due to the ' ability to use two independent pathways, their own choline/betaine pathway and the plant -alanine betaine biosynthetic pathway.
Topics: Betaine; Choline; Pseudomonas; Stress, Physiological; Methyltransferases; beta-Alanine; Vitamin B 12
PubMed: 36430408
DOI: 10.3390/ijms232213934 -
Heliyon Jun 2023Polystyrene is a plastic that leads to environmental pollution. In particular, expanded polystyrene is very light and takes up much space, causing additional...
OBJECTIVES
Polystyrene is a plastic that leads to environmental pollution. In particular, expanded polystyrene is very light and takes up much space, causing additional environmental problems. The aim of this study was to isolate new symbiotic bacteria which degraded polystyrene from mealworms.
METHODS
The population of polystyrene degrading bacteria was increased by enrichment culture of intestinal bacteria from mealworms with polystyrene as a sole carbon source. The degradation activity of isolated bacteria was evaluated by morphological change of micro-polystyrene particles and the surface change of polystyrene films.
RESULTS
Eight isolated species (, , , , , , , and ) were identified that degrade polystyrene.
CONCLUSION
Bacterial identification shows that a broad spectrum of bacteria decomposing polystyrene coexists in the intestinal tract of mealworms.
PubMed: 37426801
DOI: 10.1016/j.heliyon.2023.e17352 -
International Journal of Systematic and... Jan 2024Five strains of two novel species were isolated from the wastewater treatment systems of a pharmaceutical factory located in Zhejiang province, PR China. Strains ZM22...
Five strains of two novel species were isolated from the wastewater treatment systems of a pharmaceutical factory located in Zhejiang province, PR China. Strains ZM22 and Y6 were identified as belonging to a potential novel species of the genus , whereas strains ZM23, ZM24 and ZM25 were identified as belonging to a novel species of the genus . These strains were characterized by polyphasic approaches including 16S rRNA gene analysis, multi-locus sequence analysis, average nucleotide identity (ANI), DNA-DNA hybridization (DDH), physiological and biochemical tests, as well as chemotaxonomic analysis. Genome-based phylogenetic analysis further confirmed that strains ZM22 and Y6 form a distinct clade closely related to ATCC 11996 and DSM 17888. Strains ZM23, ZM24 and ZM25 were grouped as a separate clade closely related to DSM 14399 and LAM1902. The orthoANI and DDH results indicated that strains ZM22 and Y6 belong to the same species. In addition, genomic DNA fingerprinting demonstrated that these strains do not originate from a single clone. The same results were observed for strains ZM23, ZM24 and ZM25. Strains ZM22 and Y6 were resistant to multiple antibiotics, whereas strains ZM23, ZM24 and ZM25 were able to degrade an emerging pollutant, triclosan. The phylogenetic, physiological and biochemical characteristics, as well as chemotaxonomy, allowed these strains to be distinguished from their genus, and we therefore propose the names sp. nov. (type strain ZM22=MCCC 1K08496=KCTC 82561) and sp. nov. (type strain ZM23=MCCC 1K08497=JCM 36056), respectively.
Topics: Bacterial Typing Techniques; Base Composition; Comamonas; DNA, Bacterial; Fatty Acids; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Drug Industry; Water Purification
PubMed: 38190241
DOI: 10.1099/ijsem.0.006222