Microbial diversity and community structure changes in the rhizosphere soils of Atractylodes lancea from different planting years.

Atractylodes lancea is a type of typical traditional Chinese medicinal (TCM) herb that is economically important in China. The traditional planting method of A. lancea is to plant in situ continuously for many years, which often leads to impediments for its growth and development and soil-borne diseases. The root-associated microbiome is believed to play an important role in plant resistance and the quality of products from the plant. This study aims to reveal detailed changes in the populations of rhizosphere microorganisms, and providing theoretical guidance for the prevention and control of soil-borne diseases in A. lancea. A high-throughput sequencing approach was utilized to illustrate changes in the microbial community from different planting years. Results and conclusions: The results show that the diversity and composition of the root-associated microbiome was significantly impacted by the consecutive monoculture of A. lancea. At the level of the comparisons of the phyla, Bacteroidetes, Proteobacteria, Ascomycota, and Basidiomycota declined significantly. In contrast, the relative abundance of Actinobacteria, Acidobacteria, and Mortierellomycota distinctly increased. Comparisons at the genus level indicated that Sphingomonas, Flavobacterium, Pseudomonas, Pedobacter, and Tausonia decreased significantly, whereas Mortierella, Cylindrocarpon, Dactylonectria, and Mucor distinctly increased. In conclusion, this study helps to develop an understanding of the impediments involved in the consecutive monoculture of A. lancea.

Recurrent complicated urinary tract infection due to rare pathogen Sphingomonas paucimobilis: contamination or real deal?

Sphingomonas paucimobilis is an aerobic, oxidase-positive, yellow-pigmented, non-fermentative, Gram-negative opportunistic pathogen that rarely causes infections in humans. It is commonly found in nosocomial environments and, despite its low clinical virulence, it can be responsible for several different infections especially among patients with underlying disease. Here we describe a clinical case of a 46-year-old male paraplegic patient with a history of neurogenic bladder due to insulin-dependent diabetes mellitus and renal failure who was admitted to the urology clinic of a university hospital in Kirsehir, Turkey, with the complaints of urinary tract infection (UTI) including fever, chills, dysuria, abdominal and back pain. The urine culture was positive for Sphingomonas paucimobilis identified by the Vitek-2 system and the patient was successfully treated with oral co-trimoxazole 800/160 mg twice a day for ten days associated to cefixime and fosfomycin. A literature review of UTIs associated to Sphingomonas paucimobilis is reported as well.

Peritonitis bacteriana espontánea por Sphingomonas paucimobilis en un paciente cirrótico / Spontaneous bacterial peritonitis due to Sphingomonas paucimobilis in a cirrhotic patient

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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.

Two new nontoxic, non-pathogenic strains of Sphingomonas elodea for gellan gum production.

Two new strains of Sphingomonas elodea (designated as PHP1 and PBAD1) were tested for toxicity and pathogenicity in healthy Sprague-Dawley CD(®) IGS rats in separate studies. In each study, twelve rats/sex were administered ≥10(8) viable cells/rat by oral gavage, and four untreated rats/sex served as controls. Blood, feces, and selected organs/tissues collected at various times over the course of the 22 day study were evaluated for the presence of PHP1 or PBAD1 (depending on the study) by a validated method, to determine the potential for survival, propagation, or infectivity of PHP1 and PBAD1 cells in the rat. No mortalities, test substance-related changes in clinical or macroscopic findings, body weight or body weight gain were observed in treated animals compared with controls, indicating a lack of toxicity. PHP1 or PBAD1 were not detected in the tissue, fecal or fluid samples collected from treated animals. Therefore, neither PHP1 nor PBAD1 were pathogenic or acutely toxic under the conditions of the studies.

In vivo protection provided by a synthetic new alpha-galactosyl ceramide analog against bacterial and viral infections in murine models.

Alpha-galactosyl ceramide (α-GalCer) has been known to bind to the CD1d receptor on dendritic cells and activate invariant natural killer T (iNKT) cells, which subsequently secrete T-helper-cell 1 (Th1) and Th2 cytokines, which correlate with anti-infection activity and the prevention of autoimmune diseases, respectively. α-GalCer elicits the secretion of these two cytokines nonselectively, and thus, its effectiveness is limited by the opposing effects of the Th1 and Th2 cytokines. Reported here is the synthesis of a new α-GalCer analog (compound C34), based on the structure of CD1d, with a 4-(4-fluorophenoxy) phenyl undecanoyl modification of the N-acyl moiety of α-GalCer. Using several murine bacterial and viral infection models, we demonstrated that C34 has superior antibacterial and antiviral activities in comparison with those of several other Th1-selective glycolipids and that it is most effective by administering it to mice in a prophylactic manner before or shortly after infection.

Septic shock caused by Sphingomonas paucimobilis bacteremia in a patient with hematopoietic stem cell transplantation.

Sphingomonas paucimobilis is an aerobic gram-negative bacillus that causes a variety of infections in healthy as well as in immunocompromised individuals. The organism is usually susceptible to tetracycline, chloramphenicol, aminoglycosides, trimethoprim-sulfamethoxazole, and carbapenems. However, resistance to penicillins and the first-generation cephalosporins is commonly encountered. Reported here is a patient with acute myeloid leukemia who developed S. paucimobilis bacteremia complicated by septic shock just before receiving an autologous hematopoietic stem cell transplant (SCT) at King Faisal Specialist Hospital and Research Centre in Riyadh. The septic episode was successfully treated in the intensive care unit. To our knowledge, this is the first case report of septic shock caused by S. paucimobilis bacteremia in a hematopoietic SCT recipient.

Osteomyelitis and secondary septic arthritis caused by Sphingomonas paucimobilis.

We describe a case of osteomyelitis and secondary septic arthritis caused by Sphingomonas paucimobilis in an immunosupressed adolescent which did not present typically, leading to a delay in diagnosis. This case highlights the need to thoroughly investigate musculoskeletal pain in the immunocompromised patient in order to exclude an infection as a cause.

Sphingomonas melonis sp. nov., a novel pathogen that causes brown spots on yellow Spanish melon fruits.

A polyphasic taxonomic study was performed on the phytopathogenic bacterial strains DAPP-PG 224(T) and DAPP-PG 228, which cause brown spot on yellow Spanish melon (Cucumis melo var. inodorus) fruits. Based on the presence of glucuronosyl ceramide (SGL-1) in cellular lipids, the results of fatty acid analysis and 16S rDNA sequence comparison, the strains had been identified as belonging to the genus Sphingomonas and as phylogenetically related to Sphingomonas mali, Sphingomonas pruni and Sphingomonas asaccharolytica. The levels of 16S rDNA sequence similarity of these three species to strain DAPP-PG 224(T) were respectively 98.0, 98.0 and 97.4%. DNA-DNA hybridization experiments between strains pathogenic on melon fruit and S. mali, S. pruni and S. asaccharolytica revealed < or = 16% relatedness. Based on these results, the two isolates studied are regarded as independent from the type strains of the three species mentioned above. Sphingomonas strains from melon fruits are recognized as forming a genetically and phenotypically discrete species and to be differentiated by phenotypic characteristics from all 29 named species of the genus. Thus, the name Sphingomonas melonis sp. nov. is proposed for the isolates from diseased melon fruits. The type strain is DAPP-PG 224(T) (= LMG 19484(T) = DSM 14444(T)). The G+C content of DNA of the type strain is 65.0 mol%.