Comprehensive Genome Analysis on the Novel Species Sphingomonas panacis DCY99T Reveals Insights into Iron Tolerance of Ginseng.

Plant growth-promoting rhizobacteria play vital roles not only in plant growth, but also in reducing biotic/abiotic stress. Sphingomonas panacis DCY99T is isolated from soil and root of Panax ginseng with rusty root disease, characterized by raised reddish-brown root and this is seriously affects ginseng cultivation. To investigate the relationship between 159 sequenced Sphingomonas strains, pan-genome analysis was carried out, which suggested genomic diversity of the Sphingomonas genus. Comparative analysis of S. panacis DCY99T with Sphingomonas sp. LK11 revealed plant growth-promoting potential of S. panacis DCY99T through indole acetic acid production, phosphate solubilizing, and antifungal abilities. Detailed genomic analysis has shown that S. panacis DCY99T contain various heavy metals resistance genes in its genome and the plasmid. Functional analysis with Sphingomonas paucimobilis EPA505 predicted that S. panacis DCY99T possess genes for degradation of polyaromatic hydrocarbon and phenolic compounds in rusty-ginseng root. Interestingly, when primed ginseng with S. panacis DCY99T during high concentration of iron exposure, iron stress of ginseng was suppressed. In order to detect S. panacis DCY99T in soil, biomarker was designed using spt gene. This study brings new insights into the role of S. panacis DCY99T as a microbial inoculant to protect ginseng plants against rusty root disease.

Comparative proteomics reveal the mechanism of Tween80 enhanced phenanthrene biodegradation by Sphingomonas sp. GY2B.

Previous study concerning the effects of surfactants on phenanthrene biodegradation focused on observing the changes of cell characteristics of Sphingomonas sp. GY2B. However, the impact of surfactants on the expression of bacterial proteins, controlling phenanthrene transport and catabolism, remains obscure. To overcome the knowledge gap, comparative proteomic approaches were used to investigate protein expressions of Sphingomonas sp. GY2B during phenanthrene biodegradation in the presence and absence of a nonionic surfactant, Tween80. A total of 23 up-regulated and 19 down-regulated proteins were detected upon Tween80 treatment. Tween80 could regulate ion transport (e.g. H+) in cell membrane to provide driving force (ATP) for the transmembrane transport of phenanthrene thus increasing its uptake and biodegradation by GY2B. Moreover, Tween80 probably increased GY2B vitality and growth by inducing the expression of peptidylprolyl isomerase to stabilize cell membrane, increasing the abundances of proteins involved in intracellular metabolic pathways (e.g. TCA cycle), as well as decreasing the abundances of translation/transcription-related proteins and cysteine desulfurase, thereby facilitating phenanthrene biodegradation. This study may facilitate a better understanding of the mechanisms that regulate surfactants-enhanced biodegradation of PAHs at the proteomic level.

Modulation of Dendritic-Epithelial Cell Responses against Sphingomonas Paucimobilis by Dietary Fibers.

Non-fermenting Gram-negative bacilli, such as Sphingomonas paucimobilis (S.paucimobilis), are among the most widespread causes of nosocomial infections. Up to now, no definitive guidelines exist for antimicrobial therapy for S. paucimobilis infections. As we have shown that some dietary fibers exhibit pronounced immune-regulatory properties, we hypothesized that specific immune active dietary fibers might modulate the responses against S. paucimobilis. We studied the immunomodulatory effects of dietary fibers against S. paucimobilis on cytokine release and maturation of human dendritic cells (DCs) in co-cultures of DCs and intestinal epithelial cells (IECs). S. paucimobilis infection resulted in increased release of pro-inflammatory cytokines and chemokines by DCs/IECs; these effects were strongly attenuated by specific dietary fibers. Chicory inulin, sugar beet pectin, and both starches had the strongest regulatory effects. IL-12 and TNF-α were drastically diminished upon exposure to chicory inulin and sugar beet pectin, or both starches. High-maize 260, was more effective in the reduction of chemokine release than the others fibers tested. In summary, chicory inulin, sugar beet pectin, High-maize 260, and Novelose 330 attenuate S. paucimobilis-induced cytokines. These results demonstrate that dietary fibers with a specific chemical composition can be used to manage immune responses against pathogens such as S. paucimobilis.

Endoftalmitis poscirugía de catarata por Sphingomonas paucimobilis / Sphingomonas paucimobilis-induced endophthalmitis after cataract surgery

Se presenta la caracterización y manejo terapéutico de un caso de endoftalmitis bacteriana posoperatoria causada por el germen Sphingomonas paucimobilis. La endoftalmitis es la inflamación de los tejidos intraoculares, considerada como la más devastadora de las complicaciones posoperatorias; posee pronóstico visual muy reservado y un elevado riesgo de secuela. Las Sphingomonas paucimobilis son bacterias gramnegativas con forma de bacilo, quimioheterótrofa y estrictamente aerobias que causan enfermedades en los seres humanos, principalmente infecciones hospitalarias que típicamente son tratadas fácilmente con antibióticos. Por sus capacidades biodegradantes y biosintéticas, son pocos los reportes hallados de infección intraocular por este germen. El pronóstico visual es favorable con un diagnóstico precoz y la aplicación del tratamiento adecuado. En este artículo se presentan un caso de endoftalmitis poscirugía de catarata por Sphingomonas paucimobilis reportado en Cuba en el mes de septiembre de 2009.

The characterization and therapeutic management of a case of postsurgery bacterial endophthalmitis caused by Shingomonas paucimobilis was presented. Endophthalmitis is the inflammation of the intraocular tissues and considered as the most devastating postoperative complication. The visual prognosis of this disease is very reserved judgement and high risk of sequelae. Sphingomonas paucimobilis are bacillus-shaped, chemoheterotrophic and strictly aerobic Gramnegative bacteria that cause diseases in the human being, mainly nosocomial infections that are typically treated with antibiotics. Based on its biodegrading and biosynthetic capacities, there are few reports on intraocular infections caused by this germ. The visual prognosis is favourable when the disease is early diagnosed and adequately managed. A case of endophthalmitis following a cataract surgery and caused by Shingomonas paucimobilis in Cuba in September 2009 was presented in this article.

[A rare cause of nosocomial bacteremia: Sphingomonas paucimobilis]. / Sphingomonas paucimobilis: nadir bir hastane kaynakli bakteriyemi etkeni.

Sphingomonas paucimobilis, is a yellow-pigmented, aerobic, non-fermentative, non-spore-forming, gram-negative bacillus. Infections by S. paucimobilis which is widely found in nature and hospital environments are rarely serious or life threatening. In this report we present a case of hospital acquired bloodstream infection due to S. paucimobilis. The patient had a history of hydrocephalus diagnosed at sixth months of his birth and had experienced two ventriculoperitoneal shunt surgery. He was hospitalized and been treated for bronchopneumonia. On the 47th day of hospitalization, blood cultures (BACTEC, Becton Dickinson, USA) were taken because of a body temperature of 38.5 degrees C. One of the blood cultures was positive for gram-negative rods. After 48 h of incubation, the sub-cultures on blood agar medium yielded pure growth of a yellow, non-fermentative, gram-negative, rod-shaped bacterium. The microorganism was positive for oxidase, and esculin hydrolysis, while negative for urea and nitrate reduction and citrate utilisation. Motility was negative as well. The isolate has been identified as S. paucimobilis by using mini API (bioMerieux, France) system. The antibiotic susceptibility test was also performed with the same system and the strain was found susceptible to ceftazidime, ceftriaxone, cefoperazone, cefepime, cefotaxime, ciprofloxacin, imipenem, piperacillin-tazobactam, aztreonam, amikasin and gentamicin. Treatment with intravenous ceftriaxone (2 x 750 mg/day) was initiated. He responded well to the treatment and discharged on the tenth day. This case was reported to emphasize that S. paucimobilis should be kept in mind as a nosocomial infectious agent and the infections should be treated according to the sensitivity test results.

Formation of the metabolic intermediate 2,4,4-trimethyl-2-pentanol during incubation of a Sphingomonas sp. strain with the xeno-estrogenic octylphenol.

Degradation of branched octylphenol was studied in a bacterial culture of a Sphingomonas sp. strain. Octylphenol is considered to be the most stable degradation intermediate formed from the corresponding nonionic octylphenol polyethoxylates surfactants during biological wastewater treatment. Since octylphenol can exert estrogenic effects in wildlife, a detailed study of its biodegradation is warranted. The aerobic microbiological transformation of octylphenol was examined with and without the addition of the easily assimilable sodium acetate. In both cases the formation of the metabolite 2,4,4-trimethyl-2-pentanol, representing the intact alkyl chain as a tertiary alcohol, was observed. Since the octylphenol degradation rate was not affected by the presence of acetate, this strain did not show any diauxic metabolic behaviour when incubated with octylphenol and sodium acetate as the sources of carbon and energy. As a result of the biotransformation of octylphenol, its estrogenic potency was removed because it is the phenolic moiety that interacts with the estrogen receptors. This feature opens perspectives for the use of this strain in the framework of an adequate treatment of wastewater with high levels of alkylphenol polyethoxylates.