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Biotechnology Reports (Amsterdam,... Dec 2017Interest in novel ligninolytic bacteria has remained topical due to, in part, the maneuverability of the bacterial genome. Conversely, the fungal genome lacks the...
Interest in novel ligninolytic bacteria has remained topical due to, in part, the maneuverability of the bacterial genome. Conversely, the fungal genome lacks the dexterity for similar maneuverability thus, posing challenges in the fungal enzyme yield optimization process. Some impact of this situation includes the inability to commercialize the bio-catalytic process of lignin degradation by fungi. Consequently, this study assessed some fresh water bacteria isolates for ligninolytic and peroxidase properties through the utilization and degradation of model lignin compounds (guaiacol and veratryl alcohol) and the decolourization of selected ligninolytic indicator dyes; Azure B (AZB), Remazol Brilliant Blue R (RBBR) and Congo Red (CR). Bacterial strains with appreciable ligninolytic and peroxidase production potentials were identified through 16S rDNA sequence analysis and the nucleotide sequences deposited in the GenBank. About 5 isolates were positive for the degradation of both guaiacol (GA) and veratryl alcohol (VA) thus, accounting for about 17% of the test isolates. Similarly, AZB, RBBR and CR were respectively decolorized by 3, 2 and 5 bacterial strains thus, accounting for 10%, 7% and 17% of the test isolates. Two of the test bacterial strains were able to decolourize AZB, RBBR and CR respectively and these bacterial strains were identified as OKOH-1 and NWODO-2 with respective accession numbers as KX640917 and KX640918. Upon quantitation of the peroxidase activities; 5250 ± 0.00 U/L was recorded against OKOH-1 and 5833 ± 0.00 U/L against NWODO-2. The ligninolytic and dye decolourization properties of OKOH-1 and NWODO-2 marks for novelty particularly, as dyes with arene substituents were decolourized. Consequently, the potentials for the industrial applicability of these test bacterial strains abound as there is a dearth of information on organisms with such potentials.
PubMed: 29062721
DOI: 10.1016/j.btre.2017.10.001 -
Indian Journal of Medical Microbiology 2018Raoultella is a Gram-negative bacteria, which commonly occur in the natural environment such as water, soil and on plants. In recent years, Raoultella spp. gained more...
BACKGROUND
Raoultella is a Gram-negative bacteria, which commonly occur in the natural environment such as water, soil and on plants. In recent years, Raoultella spp. gained more interest. There is also an increasing number of publications describing mainly clinical cases involving these bacteria. Identification of Raoultella spp. is difficult due to a phylogenetic relationship with Klebsiella spp.
PURPOSE
Available biochemical tests do not always allow for their identification to species. Thus, the aim of this study was to evaluate selected methods of identification of Raoultella spp. and their differentiation from genus Klebsiella.
MATERIALS AND METHODS
In this evaluation three methods were used such as manual test ID32E (bioMérieux), automatic test VITEK2 Compact (bioMérieux) and matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) method (Bruker).
RESULTS
Good identification of the species was obtained for 81.4% of the strains in the ID32E test, 93.3% in VITEK2 Compact test, and 97.4% in MALDI-TOF MS method, respectively.
CONCLUSION
It was established that MALDI-TOF MS method is reliable in identifying genus Raoultella.
Topics: Bacterial Typing Techniques; Enterobacteriaceae; Phylogeny; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 30084410
DOI: 10.4103/ijmm.IJMM_17_99 -
Innate Immunity Dec 2010Raoultella terrigena ATCC 33257, recently reclassified from the genus Klebsiella, is a drinking water isolate and belongs to a large group of non-typeable Klebsiella and...
Raoultella terrigena ATCC 33257, recently reclassified from the genus Klebsiella, is a drinking water isolate and belongs to a large group of non-typeable Klebsiella and Raoultella strains. Using an O-antiserum against a capsule-deficient mutant of this strain, we could show a high prevalence (10.5%) of the R. terrigena O-serotype among non-typeable, clinical Klebsiella and Raoultella isolates. We observed a strong serological cross-reaction with the K. pneumoniae O12 reference strain, indicating that a large percentage of these non-typeable strains may belong to the O12 serotype, although these are currently not detectable by the K. pneumoniae O12 reference antiserum in use. Therefore, we analyzed the O-polysaccharide (O-PS) structure and genetic organization of the wb gene cluster of R. terrigena ATCC 33257, and both confirmed a close relation of R. terrigena and K. pneumoniae O12. The two strains possess an identical O-PS, lipopolysaccharide core structure, and genetic organization of the wb gene cluster. Heterologous expression of the R. terrigena wb gene cluster in Escherichia coli K-12 resulted in the WecA-dependent synthesis of an O-PS reactive with the K. pneumoniae O12 antiserum. The serological data presented here suggest a higher prevalence of the O12-serotype among Klebsiella and Raoultella isolates than generally assumed.
Topics: Antibodies, Bacterial; Cloning, Molecular; Cross Reactions; DNA, Bacterial; Gene Knockout Techniques; Klebsiella pneumoniae; O Antigens; Serotyping; Species Specificity; Water Microbiology; Water Supply
PubMed: 20053705
DOI: 10.1177/1753425909350057 -
Antibiotics (Basel, Switzerland) Jun 2022The emergence and spread of antimicrobial resistance (AMR) has become a persistent problem globally. In this study, an ozone treatment facility was established for an...
The emergence and spread of antimicrobial resistance (AMR) has become a persistent problem globally. In this study, an ozone treatment facility was established for an advanced hospital wastewater treatment in a core hospital facility in an urban area in Japan to evaluate the inactivation of antimicrobial-resistant bacteria and antimicrobials. Metagenomic DNA-seq analysis and the isolation of potential extended-spectrum -lactamase (ESBL)-producing bacteria suggested that ozone exposure for at least 20 min is required for the adequate inactivation of DNA and ESBL-producing bacteria. and species were markedly susceptible to 20-min ozone exposure, whereas and were isolated even after an 80-min exposure. These ozone-resistant bacteria might play a pivotal role as AMR reservoirs in the environment. Nine antimicrobials (ampicillin, cefdinir, cefpodoxime, ciprofloxacin, levofloxacin, clarithromycin, chlortetracycline, minocycline, and vancomycin) were detected at 373 ng/L to 27 μg/L in the hospital wastewater, and these were removed (96-100% removal) after a 40-min treatment. These results facilitate a comprehensive understanding of the AMR risk posed by hospital wastewater and provides insights for devising strategies to eliminate or mitigate the burden of antimicrobial-resistant bacteria and the flow of antimicrobials into the environment. To the best of our knowledge, this is the first report on the implementation of a batch-type, plant-scale ozone treatment system in a hospital facility to execute and evaluate the inactivation of drug-resistant bacteria and antimicrobials.
PubMed: 35884116
DOI: 10.3390/antibiotics11070862 -
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 -
International Journal of Infectious... Apr 2016Raoultella ornithinolytica is known to inhabit aquatic environments. The clinical features and outcomes of human infections caused by R. ornithinolytica have been... (Review)
Review
BACKGROUND
Raoultella ornithinolytica is known to inhabit aquatic environments. The clinical features and outcomes of human infections caused by R. ornithinolytica have been reported for only a limited number of cases.
METHODS
A retrospective study of cases of infection caused by R. ornithinolytica managed at four university hospital centres during the period before and after the introduction of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was performed. The aim was to describe the clinical and microbiological characteristics, treatments, and outcomes.
RESULTS
Among 187 R. ornithinolytica isolates identified for which clinical information was available, 71 were considered colonizers and 116 were pathogenic. A total of 112 cases of R. ornithinolytica infection were identified. Urinary tract infections, gastrointestinal infections, wound and skin infections, and bacteraemia were observed in 36%, 14%, 13%, and 5% of cases, respectively. Associated infections that have been poorly reported, such as respiratory infections, i.e. pneumonia and pleural effusion, were observed in 24% of cases. Additional diseases reported here for the first time included osteomyelitis, meningitis, cerebral abscess, mediastinitis, pericarditis, conjunctivitis, and otitis. The proportion of R. ornithinolytica isolates resistant to antibiotics was found to be relatively high: 4% of isolates were resistant to ceftriaxone, 6% to quinolones, and 13% to co-trimoxazole. The mortality rate related to infection was 5%.
CONCLUSIONS
R. ornithinolytica is an underreported, emerging hospital-acquired infection and is particularly associated with invasive procedures. R. ornithinolytica should never be considered simply a saprophytic bacterium that occasionally contaminates bronchial lavage or other deep respiratory samples or surgical sites. Physicians should be aware of the high rates of antimicrobial resistance of R. ornithinolytica isolates so that immediate broad-spectrum antibiotic treatment can be established before accurate microbiological results are obtained.
Topics: Anti-Bacterial Agents; Bacteremia; Cross Infection; Drug Resistance, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Humans; Male; Retrospective Studies
PubMed: 26921549
DOI: 10.1016/j.ijid.2016.02.014 -
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 -
Journal of Dairy Science Feb 2011Klebsiella spp. are a common cause of mastitis, milk loss, and culling on dairy farms. Control of Klebsiella mastitis is largely based on prevention of exposure of the...
Klebsiella spp. are a common cause of mastitis, milk loss, and culling on dairy farms. Control of Klebsiella mastitis is largely based on prevention of exposure of the udder to the pathogen. To identify critical control points for mastitis prevention, potential Klebsiella sources and transmission cycles in the farm environment were investigated, including oro-fecal transmission, transmission via the indoor environment, and transmission via the outdoor environment. A total of 305 samples was collected from 3 dairy farms in upstate New York in the summer of 2007, and included soil, feed crops, feed, water, rumen content, feces, bedding, and manure from alleyways and holding pens. Klebsiella spp. were detected in 100% of rumen samples, 89% of water samples, and approximately 64% of soil, feces, bedding, alleyway, and holding pen samples. Detection of Klebsiella spp. in feed crops and feed was less common. Genotypic identification of species using rpoB sequence data showed that Klebsiella pneumoniae was the most common species in rumen content, feces, and alleyways, whereas Klebsiella oxytoca, Klebsiella variicola, and Raoultella planticola were the most frequent species among isolates from soil and feed crops. Random amplified polymorphic DNA-based strain typing showed heterogeneity of Klebsiella spp. in rumen content and feces, with a median of 4 strains per 5 isolates. Observational and bacteriological data support the existence of an oro-fecal transmission cycle, which is primarily maintained through direct contact with fecal contamination or through ingestion of contaminated drinking water. Fecal shedding of Klebsiella spp. contributes to pathogen loads in the environment, including bedding, alleyways, and holding pens. Hygiene of alleyways and holding pens is an important component of Klebsiella control on dairy farms.
Topics: Animal Feed; Animals; Bedding and Linens; Cattle; Enterobacteriaceae; Environmental Microbiology; Feces; Female; Klebsiella; Mastitis, Bovine; New York; Rumen; Soil Microbiology; Water Microbiology
PubMed: 21257074
DOI: 10.3168/jds.2010-3603 -
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 -
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