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Microbiological Research Jan 2023of the current research was to use plant growth promoting rhizobacteria for sequestration and biotransformation of the toxic form of Cr and As into non-toxic form....
of the current research was to use plant growth promoting rhizobacteria for sequestration and biotransformation of the toxic form of Cr and As into non-toxic form. Remediating these contaminants using microbes is a common technique and rhizo-microbiota not only relieves metal stress but also acts as biofertilizers. Role of plant growth-promoting rhizobacterial (PGPR) strains Acinetobacter beijerinckii (C5) and Raoultella planticola (C9) in counteracting chromium and arsenic stress in soybean seedlings was assessed. The isolated rhizobacteria were able to tolerate excessive quantities (up to 1200 ppm) of chromate and arsenate in liquid media. Beside their growth in heavy metal containing media, the strains were able to bio-transform chromate and arsenate to their least toxic form. They released significant quantities of stress related metabolites including phenols, flavonoids, proline, sugars and protein even in the presence of 1200 ppm of the heavy metals. They also released several plant hormones together with indole-3-acetic acid (IAA), salicylic acid (SA) and gibberellins. Another important feature of the isolates was their ability to solubilize phosphate and release siderophores and exposure to different levels of the selected heavy metals enhanced phosphate solubilization potential of both the isolates by up to 2-fold. Release of siderophore in A. beijerinckii C5 was enhanced by increasing heavy metals concentration in the media but in case of R. planticola C9 a decline was noted. When inoculated on soybean seedlings, the isolates modulated several metabolites of the hos plant enabling them to combat heavy metal toxicity at different levels. The PGPR strains boosted host's antioxidants production which minimized the oxidative damage by scavenging excessive ROS produced under stress. Control plants showed upregulation of stress response metabolites compared to PGPR application, whereas, IAA and SA were significantly higher in PGPR associated seedlings. In conclusion, PGPR alters the physiological and metabolic responses of soybean enabling it to cope better with chromate and arsenic toxicity and grow well under the stress.
Topics: Plant Growth Regulators; Glycine max; Arsenates; Chromates; Arsenic; Metals, Heavy; Seedlings; Siderophores; Phosphates
PubMed: 36270107
DOI: 10.1016/j.micres.2022.127237 -
Research in Microbiology 2022
Corrigendum to "Proposal for reunification of the genus Raoultella with the genus Klebsiella and reclassification of Raoultella electrica as Klebsiella electrica comb. nov." [Res microbiol 172 (2021) 103851].
PubMed: 35816932
DOI: 10.1016/j.resmic.2022.103924 -
Journal of Applied Microbiology Aug 2017To isolate and identify TNT-transforming cultures from explosive-contaminated soils with the ability to produce biosurfactants.
AIMS
To isolate and identify TNT-transforming cultures from explosive-contaminated soils with the ability to produce biosurfactants.
METHODS AND RESULTS
Bacteria (pure and mixed cultures) were selected based on their ability to transform TNT in minimum media with TNT as the sole nitrogen source and an additional carbon source. TNT-transforming bacteria were identified by 16S rRNA gene sequencing. TNT transformation rates were significantly lower when no additional carbon or nitrogen sources were added. Surfactant production was enabled by the presence of TNT. Fourteen cultures were able to transform the explosive (>50%); of these, five showed a high transformation capacity (>90%), and six produced surfactants.
CONCLUSIONS
All explosive-transforming cultures contained Proteobacteria of the genera Achromobacter, Stenotrophomonas, Pseudomonas, Sphingobium, Raoultella, Rhizobium and Methylopila. These cultures transformed TNT when an additional carbon source was added. Remarkably, Achromobacter spanius S17 and Pseudomonas veronii S94 have high TNT transformation rates and are surfactant producers.
SIGNIFICANCE AND IMPACT OF THE STUDY
TNT is a highly toxic, mutagenic and carcinogenic nitroaromatic explosive; therefore, bioremediation to eliminate or mitigate its presence in the environment is essential. TNT-transforming cultures that produce surfactants are a promising method for remediation. To the best of our knowledge, this is the first report that links surfactant production and TNT transformation by bacteria.
Topics: Bacteria; Biodegradation, Environmental; Biotransformation; Carbon; Nitrogen; Soil Microbiology; Soil Pollutants; Surface-Active Agents; Trinitrotoluene
PubMed: 28561275
DOI: 10.1111/jam.13504 -
Frontiers in Microbiology 2022A two-way relationship between diabetes and periodontitis has been discussed recently. Periodontitis microbiota might affect the immune homeostasis of diabetes, but the...
A two-way relationship between diabetes and periodontitis has been discussed recently. Periodontitis microbiota might affect the immune homeostasis of diabetes, but the molecular mechanism of their interactions is still not clear. The aims of this study were to clarify the possible immune regulatory effects of periodontitis microbiota on diabetes and the correlation between immunomodulation and ectopic colonization. A model of germ-free mice with streptozotocin-induced type 1 diabetes mellitus (T1D), which was orally inoculated with mixed saliva samples for 2 weeks, was used in this study. Those mice were randomly divided into two groups, namely, SP (where the T1D mice were orally inoculated with mixed saliva samples from periodontitis patients) and SH (where the T1D mice were orally inoculated with mixed saliva samples from healthy subjects). Ectopic colonization of saliva microbiota was assessed using culture-dependent method and Sanger sequencing, and the composition of gut microbiota was analyzed using 16S rRNA gene sequencing. Changes in 15 types of immune cells and six cytokines either from the small intestine or spleen were detected by multicolor flow cytometry. The correlation between gut microbiota and immune cells was evaluated by redundancy analysis. Although periodontitis microbiota minorly colonized the lungs, spleens, and blood system, they predominantly colonized the gut, which was mainly invaded by . SH and SP differed in beta diversity of the gut bacterial community. Compared to SH, microbial alteration in small intestine occurred with an increase of , , , , and a decrease of in SP. More types of immune cells were disordered in the spleen than in the small intestine by periodontitis microbiota, mainly with a dramatical increase in the proportion of macrophages, plasmacytoid dendritic cells (pDCs), monocytes, group 3 innate lymphoid cells, CD4-CD8- T cells and Th17 cells, as well as a decline of αβT cells in SP. Cytokines of IFNγ, IL17, and IL22 produced by CD4 + T cells as well as IL22 produced by ILCs of small intestine rose in numbers, and the intestinal and splenic pDCs were positively regulated by gut bacterial community in SP. In conclusion, periodontitis microbiota invasion leads to ectopic colonization of the extra-oral sites and immune cells infiltration, which might cause local or systemic inflammation. Those cells are considered to act as a "bridge" between T1D and periodontitis.
PubMed: 35756043
DOI: 10.3389/fmicb.2022.889415 -
Veterinary World Jul 2020is one of the emerging gram-negative bacteria, which associated with foodborne illness. Researches affirmed that distinguish between and are difficult, as they are...
BACKGROUND AND AIM
is one of the emerging gram-negative bacteria, which associated with foodborne illness. Researches affirmed that distinguish between and are difficult, as they are phylogenetic related. The evolution of multidrug resistance of strains gained more concern for recognition of the pathogen which supports in controlling the disease and minify its threat. This study sought to find a reliable tool for the identification of , isolated from chicken product samples, and assessed the resistance profile of . using antibiogram sensitivity tests.
MATERIALS AND METHODS
Forty samples of chicken products were collected between January and September 2019 from different markets in Alexandria Governorate, Egypt. The products included nuggets, strips, burgers, luncheon meats, pane, frankfurters, and minced chicken meat. The samples were transferred to the Reference Laboratory. The samples were subjected to isolation, biochemical reaction testing, phenotypic system analytical profile index (API) E20, and a detection of antimicrobial susceptibility test. Phenotypic identification was confirmed through matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS).
RESULTS
Thirty-three bacterial isolates (82.50%) out of 40 samples were isolated into pure cultures from the chicken samples. Three isolates (9.09%) were positive for , while 30 isolates (90.91%) exhibited growth characters for different pathogens (, , , and ). The isolates of were resistant to five types of antibiotics and sensitive to two types of antibiotics.
CONCLUSION
This study reported the first case of found in chicken products in Egypt. Phenotypic system API 20E and MALDI-TOF MS were found to be reliable tools for confirming the diagnosis of a. As it provides rapid identification with high sensitivity and specificity for , which often do not require a molecular procedure for confirmation.
PubMed: 32848326
DOI: 10.14202/vetworld.2020.1473-1479 -
Ecotoxicology and Environmental Safety Sep 2023Polyolefin plastics, such as polyethylene (PE) and polystyrene (PS), are the most widely used synthetic plastics in our daily life. However, the chemical structure of...
Polyolefin plastics, such as polyethylene (PE) and polystyrene (PS), are the most widely used synthetic plastics in our daily life. However, the chemical structure of polyolefin plastics is composed of carbon-carbon (C-C) bonds, which is extremely stable and makes polyolefin plastics recalcitrant to degradation. The growing accumulation of plastic waste has caused serious environmental pollution and has become a global environmental concern. In this study, we isolated a unique Raoultella sp. DY2415 strain from petroleum-contaminated soil that can degrade PE and PS film. After 60 d of incubation with strain DY2415, the weight of the UV-irradiated PE (UVPE) film and PS film decreased by 8% and 2%, respectively. Apparent microbial colonization and holes on the surface of the films were observed by scanning electron microscopy (SEM). Furthermore, the Fourier transform infrared spectrometer (FTIR) results showed that new oxygen-containing functional groups such as -OH and -CO were introduced into the polyolefin molecular structure. Potential enzymes that may be involved in the biodegradation of polyolefin plastics were analyzed. These results demonstrate that Raoultella sp. DY2415 has the ability to degrade polyolefin plastics and provide a basis for further investigating the biodegradation mechanism.
Topics: Polystyrenes; Polyethylene; Petroleum; Soil; Enterobacteriaceae; Biodegradation, Environmental; Carbon; Plastics
PubMed: 37429089
DOI: 10.1016/j.ecoenv.2023.115232 -
Clinical Microbiology and Infection :... Mar 2016The genus Raoultella was excised from Klebsiella in 2001, but difficulties in its identification may have led to an underestimation of its incidence and uncertainty on... (Review)
Review
The genus Raoultella was excised from Klebsiella in 2001, but difficulties in its identification may have led to an underestimation of its incidence and uncertainty on its pathogenic role. Recently, clinical reports involving Raoultella have increased, probably through the introduction of mass-spectrometry in clinical microbiology laboratories and the development of accurate molecular techniques. We performed a retrospective analysis using our blood culture collection (2011-14) to identify Raoultella isolates that could have been erroneously reported as Klebsiella. PCR and gene sequencing of highly specific chromosomal class A β-lactamase genes was established as the reference method, and compared with 16S rRNA and rpoβ sequencing, as well as matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), MicroScan Walkaway system and API20E biochemical identification. MALDI-TOF and rpoβ correctly identified all Raoultella isolates, whereas 16S rRNA provided inconclusive results, and MicroScan and API20E failed to detect this genus. The analysis of the clinical characteristics of all Raoultella bacteraemia cases reported in the literature supports the role of Raoultella as an opportunistic pathogen that causes biliary tract infections in elderly patients who suffer from some kind of malignancy or have undergone an invasive procedure. Two salient conclusions are that Raoultella shows tropism for the biliary tract and so its identification could help clinicians to suspect underlying biliary tract disease when bacteraemia occurs. Concomitantly, as most phenotypic identification systems are not optimized for the identification of Raoultella, the use of MALDI-TOF or additional phenotypic tests is recommended for the reliable identification of this genus.
Topics: Adult; Aged; Aged, 80 and over; Bacteremia; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Genes, Bacterial; Humans; Male; Middle Aged; Polymerase Chain Reaction; Sequence Analysis, DNA; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 26577139
DOI: 10.1016/j.cmi.2015.10.035 -
Molecular Plant-microbe Interactions :... Feb 2017Mechanical damage caused by insect feeding along with components present in insect saliva and oral secretions are known to induce jasmonic acid-mediated defense...
Mechanical damage caused by insect feeding along with components present in insect saliva and oral secretions are known to induce jasmonic acid-mediated defense responses in plants. This study investigated the effects of bacteria from oral secretions of the fall armyworm Spodoptera frugiperda on herbivore-induced defenses in tomato and maize plants. Using culture-dependent methods, we identified seven different bacterial isolates belonging to the family Enterobacteriacea from the oral secretions of field-collected caterpillars. Two isolates, Pantoea ananatis and Enterobacteriaceae-1, downregulated the activity of the plant defensive proteins polyphenol oxidase and trypsin proteinase inhibitors (trypsin PI) but upregulated peroxidase (POX) activity in tomato. A Raoultella sp. and a Klebsiella sp. downregulated POX but upregulated trypsin PI in this plant species. Conversely, all of these bacterial isolates upregulated the expression of the herbivore-induced maize proteinase inhibitor (mpi) gene in maize. Plant treatment with P. ananatis and Enterobacteriaceae-1 enhanced caterpillar growth on tomato but diminished their growth on maize plants. Our results highlight the importance of herbivore-associated microbes and their ability to mediate insect plant interactions differently in host plants fed on by the same herbivore.
Topics: Animals; Bacteria; Gastrointestinal Microbiome; Herbivory; Insect Proteins; Larva; Solanum lycopersicum; Saliva; Salivary Proteins and Peptides; Spodoptera; Weight Gain; Zea mays
PubMed: 28027025
DOI: 10.1094/MPMI-11-16-0240-R -
Evidence-based Complementary and... 2022Mobile phones have become an indispensable part of human lives for communication, education, and entertainment activities. This study aims to evaluate the diversity...
Mobile phones have become an indispensable part of human lives for communication, education, and entertainment activities. This study aims to evaluate the diversity pattern of bacterial contaminants on mobiles and to check antibiotic resistance profiles in 105 samples. The study revealed a contamination of 51% in men and 49% in women, the highest in the 21- to 30-year age group, evidencing the extreme use of mobiles by teenagers. The study observed Gram-negative bacteria (63%) versus Gram-positive bacteria (37%). Overall, Gram-negative bacterial isolates showed the highest sensitivity to antibiotic nitrofurantoin (90%) and the lowest in ampicillin (35%). Gram positive has highest incidence of sensitivity towards tigecycline (100%) and lowest in cefoxitin (20%). ESL producers were found to be 21.0% and highest being in (35%) followed by (31%). have been identified on the mobile phones for the very first time. Interestingly, some soil microbes were also isolated and unfortunately found to have some antibiotic resistance like and . The results revealed that mobiles were contaminated with multidrug-resistant (MDR) pathogens, and this study also showed that few of the saprophytic soil strains have antibiotic resistance, which can be an alarming situation that needs to be addressed.
PubMed: 35668788
DOI: 10.1155/2022/1527488 -
Molecules (Basel, Switzerland) Aug 2023Biological methods are currently the most commonly used methods for removing hazardous substances from land. This research work focuses on the remediation of...
Biological methods are currently the most commonly used methods for removing hazardous substances from land. This research work focuses on the remediation of oil-contaminated land. The biodegradation of aliphatic hydrocarbons and PAHs as a result of inoculation with biopreparations B1 and B2 was investigated. Biopreparation B1 was developed on the basis of autochthonous bacteria, consisting of strains sp. IN118, sp. IN101, IN53, IN119, IN113 and sp. IN109, whereas biopreparation B2 was enriched with fungi, such as , , sp., , . As a result of biodegradation tests conducted under ex situ conditions for soil inoculated with biopreparation B1, the concentrations of TPH and PAH were reduced by 31.85% and 27.41%, respectively. Soil inoculation with biopreparation B2 turned out to be more effective, as a result of which the concentration of TPH was reduced by 41.67% and PAH by 34.73%. Another issue was the phytoremediation of the pre-treated G6-3B2 soil with the use of . The tests were carried out in three systems (system 1-soil G6-3B2 + ; system 2-soil G6-3B2 + biopreparation B2 + ; system 3-soil G6-3B2 + biopreparation B2 with γ-PGA + ) for 6 months. The highest degree of TPH and PAH reduction was obtained in system 3, amounting to 65.35% and 60.80%, respectively. The lowest phytoremediation efficiency was recorded in the non-inoculated system 1, where the concentration of TPH was reduced by 22.80% and PAH by 18.48%. Toxicological tests carried out using Phytotoxkit, Ostracodtoxkit and Microtox Solid Phase tests confirmed the effectiveness of remediation procedures and showed a correlation between the concentration of petroleum hydrocarbons in the soil and its toxicity. The results obtained during the research indicate the great potential of bioremediation practices with the use of microbial biopreparations and in the treatment of soils contaminated with petroleum hydrocarbons.
Topics: Zea mays; Biodegradation, Environmental; Hazardous Substances; Actinomycetales; Enterobacteriaceae
PubMed: 37630356
DOI: 10.3390/molecules28166104