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Communications Chemistry May 2023Proteorhodopsins (PRs), bacterial light-driven outward proton pumps comprise the first discovered and largest family of rhodopsins, they play a significant role in life...
Proteorhodopsins (PRs), bacterial light-driven outward proton pumps comprise the first discovered and largest family of rhodopsins, they play a significant role in life on the Earth. A big remaining mystery was that up-to-date there was no described bacterial rhodopsins pumping protons at acidic pH despite the fact that bacteria live in different pH environment. Here we describe conceptually new bacterial rhodopsins which are operating as outward proton pumps at acidic pH. A comprehensive function-structure study of a representative of a new clade of proton pumping rhodopsins which we name "mirror proteorhodopsins", from Sphingomonas paucimobilis (SpaR) shows cavity/gate architecture of the proton translocation pathway rather resembling channelrhodopsins than the known rhodopsin proton pumps. Another unique property of mirror proteorhodopsins is that proton pumping is inhibited by a millimolar concentration of zinc. We also show that mirror proteorhodopsins are extensively represented in opportunistic multidrug resistant human pathogens, plant growth-promoting and zinc solubilizing bacteria. They may be of optogenetic interest.
PubMed: 37130895
DOI: 10.1038/s42004-023-00884-8 -
Journal of Ophthalmic Inflammation and... May 2023
PubMed: 37126159
DOI: 10.1186/s12348-023-00346-1 -
Medicina (Kaunas, Lithuania) Mar 2023is a gram-negative bacillus that is widely distributed in the environment but rarely causes infections in humans. Meningitis caused by is an extremely rare clinical... (Review)
Review
is a gram-negative bacillus that is widely distributed in the environment but rarely causes infections in humans. Meningitis caused by is an extremely rare clinical entity with very few reported cases in the literature. The clinical presentation and management of meningitis are not well established, and further research is needed to better understand this rare infection. Therefore, the goal of this study was to present probably the only case of meningitis caused by co-infection with and and to describe the diagnostic and therapeutic challenges encountered, in correlation with the other very few reported cases of meningitis. A 64-year-old male farmer residing in a rural area was admitted with symptoms of severe headache, somnolence, and confusion. He had several comorbidities, including adrenal insufficiency, duodenal ulcer, and hypercholesterolemia. Lumbar puncture showed elevated leukocyte counts, glucose, and a marked rise of cerebrospinal fluid (CSF) proteins, indicating bacterial meningitis, which was confirmed by CSF culture that isolated and . Antituberculosis therapy was initiated with isoniazid (300 mg/day), rifampicin (600 mg/day), pyrazinamide (2000 mg/day), and streptomycin (1 g/day). Ceftriaxone was introduced nine days later, after CSF culture grew , and was discharged without complications after 40 days of hospitalization. The literature search revealed a total of 12 published cases of meningitis in patients ranging from two months old to 66 years old. Among these cases, eight (66%) reported a favorable outcome, while two (17%) cases resulted in a poor outcome, and two (17%) were fatal. It was observed among the 13 identified cases (including ours) that the CSF white blood cell count had an average of 178.9 × 10/mm, an average glucose level of 33.0 mg/dL, and an average protein count of 294.2 mg/dL. Most cases improved appropriately under antibiotic therapy with intravenous ceftriaxone, Meropenem, and Vancomycin. In conclusion, although extremely rare, meningitis has good outcomes even in immunocompromised patients with appropriate antibiotic therapy and close monitoring, while the diagnosis should not be excluded even in immunocompetent patients.
Topics: Male; Humans; Middle Aged; Infant; Mycobacterium tuberculosis; Ceftriaxone; Anti-Bacterial Agents; Meningitis, Bacterial; Immunocompromised Host
PubMed: 37109645
DOI: 10.3390/medicina59040687 -
Journal of Applied Microbiology Apr 2023Investigate the effects of different nitrogen sources on the metabolic characteristics of Sphingomonas paucimobilis during gellan gum (GG) production was helpful for...
AIM
Investigate the effects of different nitrogen sources on the metabolic characteristics of Sphingomonas paucimobilis during gellan gum (GG) production was helpful for developing optimized conditions that are widely applicable to all GG production processes.
METHODS AND RESULTS
We compared the effects of organic nitrogen (ON) and inorganic nitrogen (IN) sources during GG production using transcriptome sequencing. Our results showed that compared with the IN source, the ON source effectively improved the cell number and GG production of S. paucimobilis during fermentation. There were significant differences in gene transcription levels between the ON and IN groups at different fermentation times.
CONCLUSIONS
The transcriptional levels of multiple genes in the pathways from α-D-glucose-1P to glyceraldehyde-3P were reduced in the ON group, whereas those of multiple genes in the pathways from glyceraldehyde-3P to acetyl-CoA were significantly enhanced in the ON group after 12 h of fermentation. The transcription levels of multiple genes participating in the citrate cycle and upstream of fatty acid metabolism pathways were significantly enhanced in the ON group after 12 h of fermentation. Except for the transcripts per million (TPMs) of pgm and rfbA genes in ON, which were significantly higher than those in IN at 12 h after fermentation, the TPMs of the majority of genes in ON were significantly lower than those in IN. The transcription levels of genes participating in the transformation of N-acetyl-D-glucosamine (GlcNAc) to UDP-N-acetyl-alpha-D-glucosamine (UDP-GlcNAc) were enhanced in the ON group during the fermentation process.
Topics: Nitrogen; Transcriptome; Glyceraldehyde; Polysaccharides, Bacterial; Uridine Diphosphate
PubMed: 37081775
DOI: 10.1093/jambio/lxad081 -
International Journal of Molecular... Mar 2023Digital dermatitis (DD) is the second most prevalent disease in dairy cattle. It causes significant losses for dairy breeders and negatively impacts cows' welfare and...
Digital dermatitis (DD) is the second most prevalent disease in dairy cattle. It causes significant losses for dairy breeders and negatively impacts cows' welfare and milk yield. Despite this, its etiology has not been entirely identified, and available data are limited. Antibiotic therapy is a practical method for managing animal health, but overuse has caused the evolution of antibiotic-resistant bacteria, leading to a loss in antimicrobial efficacy. The antimicrobial properties of metal nanoparticles (NPs) may be a potential alternative to antibiotics. The aim of this study was to determine the biocidal properties of AgNPs, CuNPs, AuNPs, PtNPs, FeNPs, and their nanocomposites against pathogens isolated from cows suffering from hoof diseases, especially DD. The isolated pathogens included , I, II, , and . Cultures were prepared in aerobic and anaerobic environments. The viability of the pathogens was then determined after applying nanoparticles at various concentrations. The in vitro experiment showed that AgNPs and CuNPs, and their complexes, had the highest biocidal effect on pathogens. The NPs' biocidal properties and their synergistic effects were confirmed, which may forecast their use in the future treatment and the prevention of lameness in cows, especially DD.
Topics: Female; Cattle; Animals; Digital Dermatitis; Lameness, Animal; Gold; Metal Nanoparticles; Anti-Infective Agents; Anti-Bacterial Agents; Cattle Diseases; Dairying
PubMed: 37047119
DOI: 10.3390/ijms24076146 -
Brazilian Journal of Biology = Revista... 2023Bacteria responsible for causing infections are common in hospital environments, water, soil, and food products. The infection risk is intensified by the absence of...
Bacteria responsible for causing infections are common in hospital environments, water, soil, and food products. The infection risk is intensified by the absence of public sanitation, poor quality of life, and food scarcity. These external factors promote the dissemination of pathogens by direct contamination or biofilm formation. In this work, we identified bacterial isolates obtained from intensive care units in the southern region of Tocantins, Brazil. We compared matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques and 16S ribosomal ribonucleic acid (rRNA) molecular analysis; we also performed phenotypic characterization. Fifty-six isolates characterized using morphotinctorial tests were classified as gram-positive (80.4%; n = 45) and gram-negative (19.6%; n = 11) and were resistant to several antibiotic classes; notably, we identified the blaOXA-23 resistance gene in the ILH10 isolate. Microbial identification using MALDI-TOF MS resulted in the identification of Sphingomonas paucimobilis and Bacillus circulans. 16S rRNA sequencing revealed four isolates belonging to the genera Bacillus and Acinetobacter. The similarity was superior to 99% for Acinetobacter schindleri in the Basic Local Alignment Search Tool (BLAST), grouped in the clade superior to 90%. Several strains isolated from intensive care units (ICU) were resistant to various antibiotic classes. These techniques allowed for the identification of several microorganisms of importance in public health, enabling improvements in human infection control and proving the quality of inputs, food, and water.
Topics: Humans; RNA, Ribosomal, 16S; Quality of Life; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Anti-Bacterial Agents; Water; Intensive Care Units; Population Health
PubMed: 37018840
DOI: 10.1590/1519-6984.269778 -
Archives of Microbiology Mar 2023Sphingomonas paucimobilis ZJSH1 is an endophytic bacterium isolated from the roots of Dendrobium officinale with the ability to promote plant growth. It was found that...
Sphingomonas paucimobilis ZJSH1 is an endophytic bacterium isolated from the roots of Dendrobium officinale with the ability to promote plant growth. It was found that the genome of strain ZJSH1 had gene fragment rearrangement compared with the genomes of the other four strains of S. paucimobilis, and the genome was integrated with phage genes. Functional analysis showed that the strain contained colonization-related genes, chemotaxis and invasion. A variety of genes encoding active materials, such as hormones (IAA, SA, ABA and zeaxanthin), phosphate cycle, antioxidant enzymes, and polysaccharides were identified which provide the strain with growth promotion and stress-resistant characteristics. Experiments proved that S. paucimobilis ZJSH1 grew well in media containing 80 g/L sodium chloride, 240 g/L polyethylene glycol and 800 μmol/L Cd, indicating its potential for resistance to stresses of salt, drought and cadmium, respectively. S. paucimobilis ZJSH1 is the only endophytic bacterium of this species that has been reported to promote plant growth. The analysis of its genome is conducive to understanding its growth-promoting mechanism and laying a foundation for the development and utilization of this species in the field of agriculture.
Topics: Dendrobium; Sphingomonas; Cadmium; Antioxidants
PubMed: 36959350
DOI: 10.1007/s00203-023-03459-2 -
Journal of Ophthalmic Inflammation and... Mar 2023Over the past 20 years, scattered reports have emerged about a low virulence, gram negative bacillus, Sphingomonas paucimobilis, causing unpredictable clinical...
Over the past 20 years, scattered reports have emerged about a low virulence, gram negative bacillus, Sphingomonas paucimobilis, causing unpredictable clinical presentations of endophthalmitis. Previous reports have characterised the organism as being resistant to aggressive treatment and prone to recurrence up to several months later, with few warning signs of any residual infection. We report a case of a 75 year-old male who returned 10 days after a left eye cataract surgery with an atypical, indolent endophthalmitis. He was treated with broad-spectrum intravitreal antibiotics and vitrectomy, and despite initial improvement, the patient suffered a recurrence after 2 weeks, necessitating successive rounds of intravitreal antibiotics. While our patient was able to achieve an excellent final visual acuity of 6/9, there are several cases in the literature reporting similar cases with much worse visual outcomes. Further research is required to elucidate early warning signs that may indicate a recurrence of S. paucimobilis infection, and the underlying mechanism by which it is resistant to standard endophthalmitis therapy. Alongside this case, we review and summarise the literature on postoperative endophthalmitis involving this organism.
PubMed: 36872422
DOI: 10.1186/s12348-023-00325-6 -
Current Eye Research Jun 2023To report the clinical presentations, complications, and outcomes of Sphingomonas paucimobilis-specific lacrimal drainage infections.
PURPOSE
To report the clinical presentations, complications, and outcomes of Sphingomonas paucimobilis-specific lacrimal drainage infections.
METHODS
A retrospective chart review of all patients diagnosed with lacrimal infections and managed at a tertiary care Dacryology Service from November 2015 to May 2022 over a 6.5-year period were recruited and analyzed. Data collected include demographic details, clinical presentation, microbiological diagnosis, antibiotic susceptibility profiles, management, complications, and outcomes. The microbiological techniques employed were aerobic and anaerobic cultures, phenotypic identification with VITEK 2 system, polymerase chain reaction, antibiotic sensitivity profile and minimal inhibitory concentration.
RESULTS
Twelve specific lacrimal drainage infections of 11 patients were identified. Of these five were canaliculitis and seven were acute dacryocystitis. All the seven acute dacryocystitis presented in an advanced stage; five were with lacrimal abscess and two with orbital cellulitis. The antibiotic susceptibility profile of canaliculitis and acute dacryocystitis were comparable and the organism was sensitive to several classes of antibiotics. The outcomes of punctal dilatation and nonincisional curettage were effective for canaliculitis. Patients with acute dacryocystitis had advanced clinical stage at presentation but responded well to intensive systemic management and had excellent anatomical and functional outcomes with dacryocystorhinostomy.
CONCLUSION
-specific lacrimal sac infections can have aggressive clinical presentations and need early and intensive therapy. The outcomes are excellent with multimodal management.
Topics: Humans; Sphingomonas; Canaliculitis; Retrospective Studies; Dacryocystitis; Dacryocystorhinostomy; Anti-Bacterial Agents
PubMed: 36803078
DOI: 10.1080/02713683.2023.2183482 -
IDCases 2023This report describes a case of Sphingomonas paucimobilis bacteremia and infective endocarditis with a mycotic aneurysm in a young patient with Crohn's disease. Our...
This report describes a case of Sphingomonas paucimobilis bacteremia and infective endocarditis with a mycotic aneurysm in a young patient with Crohn's disease. Our patient reported prolonged intermittent fever followed by sudden hemiparesis and a tonic clonic convulsion. His blood cultures showed growth of , and further cardiac imaging revealed the presence of a vegetation with severe valvular regurgitation. Cerebral angiography showed middle cerebral artery occlusion and aneurysm. The patient was treated with meropenem for 6 weeks, coupled with aortic valve replacement, and coiling of the aneurysm. Our patient recovered with good results. is an opportunistic gram-negative pathogen of growing importance in the clinical setting.
PubMed: 36654734
DOI: 10.1016/j.idcr.2023.e01687