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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 -
Applied Biochemistry and Biotechnology Oct 2022Heparin is a class of highly sulfated, acidic, linear, and complex polysaccharide that belongs to the heparin/heparan sulfate (HS) glycosaminoglycans family. Enzymatic...
Heparin is a class of highly sulfated, acidic, linear, and complex polysaccharide that belongs to the heparin/heparan sulfate (HS) glycosaminoglycans family. Enzymatic depolymerization of heparin by heparinases is a promising strategy for the production of ultra-low molecular weight heparins (ULMWHs) as anticoagulants. In the present study, a novel heparinase-producing strain Raoultella NX-TZ-3-15 was isolated and identified from soil samples. Herein, the heparinase gene MBP-H1 was cloned to the pBENT vector to enable expression in Escherichia coli. The optimized conditions made the activity of recombinant heparinase reach the highest level (2140 U/L). The overexpressed MBP-H1 was purified by affinity chromatography and a purity of more than 90% was obtained. The condition for biocatalysis was also optimized and three metal ions Ca, Co, and Mg were utilized to activate the reaction. In addition, the kinetics regarding the new fusion heparinase was also determined with a V value of 11.29 μmol/min and a K value of 31.2 μmol/L. In short, due to excellent K and V, the recombinant enzyme has great potential to be used in the clinic in medicine and industrial production of low or ultra-low molecule weight heparin.
Topics: Anticoagulants; Cloning, Molecular; Escherichia coli; Glycosaminoglycans; Heparin; Heparin Lyase; Heparin, Low-Molecular-Weight; Heparitin Sulfate; Polysaccharide-Lyases; Soil
PubMed: 35679015
DOI: 10.1007/s12010-022-03917-5 -
Biodegradation Apr 2023The mining and leakage of molybdenum (Mo) can cause environmental contamination which has not been realized until recently. Bacteria that can mitigate Mo-contamination...
The mining and leakage of molybdenum (Mo) can cause environmental contamination which has not been realized until recently. Bacteria that can mitigate Mo-contamination was enriched and isolated. The low temperature and different pH conditions were considered to analysis its feasibility in Northern China which suffers from a long time of low temperatures every year. The result showed that the removal rate of MoO by Raoultella ornithinolytica A1 reached 30.46% at 25 °C and pH 7.0 in Luria-Bertani medium (LB). Meanwhile, A1 also showed some efficiency in the reduction of MoO in low phosphate molybdate medium (LPM), which reached optimum at the MoO concentration of 10 mM. The results of FTIR indicated that the cell wall performed an essential role in the MoO removal process, which was illustrated by the distribution of Mo in A1 (Mo bound to cell wall accounted for 92.29% of the total MoO removed). In addition, low temperature (10 °C) effect the removal rate of MoO by - 8.38 to 11.66%, indicating the potential for the in-situ microbial remediation of Mo-contaminated environments in low temperature areas.
Topics: Molybdenum; Enterobacteriaceae; China
PubMed: 36596915
DOI: 10.1007/s10532-022-10011-4 -
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 -
Journal of Environmental Sciences... Feb 2022External organic carbon sources are needed to provide electron donors for the denitrification of wastewater with a low COD/NO-N (C/N) ratio, increasing the treatment...
External organic carbon sources are needed to provide electron donors for the denitrification of wastewater with a low COD/NO-N (C/N) ratio, increasing the treatment cost. The economic strategy is to enhance the bioactivity and/or biodiversity of denitrifiers to efficiently utilize organic substances in wastewater. In this study, novel zero-valent iron (ZVI) composite carriers were prepared and implemented in a suspended carrier biofilm reactor to enhance the bioactivity and/or biodiversity of denitrifiers. At the influent C/N ratio of 4 (COD was 179.5 ± 5.0 mg/L and TN was 44.2 ± 0.8 mg/L), COD and TN removal efficiencies were 85.1% and 66.4%, respectively, in the reactors filled with 3 wt% ZVI composite carriers. In contrast, COD and TN removal efficiencies were 70.4% and 55.3%, respectively, in the reactor filled with conventional high-density polyethylene (HDPE) biofilm carriers. The biofilm formation on the 3 wt% ZVI composite carriers was optimized due to its higher roughness (surface square roughness increased from 76.0 nm to 93.8 nm) and favorable hydrophilicity (water contact angle dropped to 72.5° ± 1.4° from 94.3° ± 3.2°) compared with the HDPE biofilm carriers. In addition, heterotrophic denitrifiers, Thauera and Dechloromonas, were enriched, whereas autotrophic denitrifiers, Raoultella and Thiobacillus, exhibited high relative abundance in the biofilm of ZVI composite carriers. The coexistence of heterotrophic denitrifiers and autotrophic denitrifiers on the surface of ZVI composite carriers provided mixotrophic metabolism of denitrification (including heterotrophic and iron-based autotrophic), thereby ensuring effective denitrification for wastewater with a low C/N ratio without external organic carbon source addition.
Topics: Autotrophic Processes; Bioreactors; Denitrification; Iron; Nitrogen; Wastewater
PubMed: 34955202
DOI: 10.1016/j.jes.2021.05.021 -
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 -
Cureus Oct 2023We present a case of () infection that resulted in community-acquired pneumonia in an immunocompetent patient with an eight-week history of productive cough. This...
We present a case of () infection that resulted in community-acquired pneumonia in an immunocompetent patient with an eight-week history of productive cough. This gram-negative bacterium is typically found in the environment and has the potential to infect humans. infections in humans have been recorded in several case reports from throughout the world in recent years, usually affecting immunocompromised patients. Although is sensitive to most antibiotic groups, recent studies have revealed an increase in the infrequent acquisition of resistance genes in , such as carbapenem resistance, making this pathogen a potential emergent threat. Our patient acquired pneumonia in the absence of any underlying risk factors, making this the first case in the UK of causing community-acquired pneumonia in an immunocompetent person.
PubMed: 38021927
DOI: 10.7759/cureus.47188 -
Cureus Mar 2024The case presentation discusses the clinical evaluation and treatment of a two-year-old female exhibiting symptoms such as dysuria, constipation, and foul-smelling...
The case presentation discusses the clinical evaluation and treatment of a two-year-old female exhibiting symptoms such as dysuria, constipation, and foul-smelling urine. Upon evaluation, the patient was found to be co-infected with Raoultella planticola and Escherichia coli. This co-infection poses unique challenges in diagnosis and treatment, as both pathogens may contribute to the manifestation of symptoms. The initial diagnosis of Raoultella planticola is notable, given its relatively rare occurrence and the potential for misdiagnosis. This case study contributes to our understanding of diagnosing and distinguishing symptoms at various stages of the illness, particularly in cases of co-infection. Following an initial urinalysis and urine culture confirming the presence of both pathogens, a 10-day course of antibiotics was prescribed. Subsequent examinations at Rady Children's Hospital-San Diego included kidney and abdomen imaging to rule out underlying issues. The co-infection underscores the importance of thorough diagnostic procedures and tailored treatment approaches. Additionally, it highlights the need for heightened awareness among healthcare providers regarding emerging pathogens and their potential clinical implications.
PubMed: 38686243
DOI: 10.7759/cureus.57262