In this study, a bacterial strain Chryseobacterium bernardetii WK-3 was isolated from the rhizosphere soil of a uranium tailings in Southern China. It can efficiently adsorb hexavalent uranium with an adsorption ratio of 92.3%. The influence of different environmental conditions on the adsorption ratio of Chryseobacterium bernardetii strain WK-3 was investigated, and the adsorption mechanism was preliminarily discussed by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). The results showed that the optimal adsorption conditions for U(VI) by Chryseobacterium bernardetii strain WK-3 were pH = 5, temperature 30 ℃, NaCl concentration 1%, and inoculation volume 10%. When the initial concentration of U was 50 ~ 150 mg/L, the adsorption capacity of Chryseobacterium bernardetii strain WK-3 to U(VI) reached the maximum and maintained the equilibrium at 44 h. SEM-EDS results showed that phosphorus in cells participates in the interaction of uranyl ions, which may indicate that phosphate was produced during cell metabolism and was further combined to form U(VI)-phosphate minerals. In summary, Chryseobacterium bernardetii strain WK-3 would be a promising alternative for environmental uranium contamination remediation.

BACKGROUND: Elizabethkingia meningoseptica is an emerging nosocomial pathogen implicated in neonatal sepsis with high mortality and morbidities. However, there is very limited data regarding the characteristics as well as outcomes following this infection, particularly in developing countries.
METHODS: We conducted a retrospective observational study of all infants with culture-positive Elizabethkingia sepsis as part of an outbreak, to study their clinical and epidemiological characteristics, as well as their antimicrobial susceptibility patterns, using a structured proforma from the neonatal intensive care unit database. Analysis was done using descriptive statistics and predictors of mortality and hydrocephalus were also identified.
RESULTS: Of the 21 neonates enrolled, 9 (42.9%) were male, with a mean gestational age and birth weight of 31.7 ± 3.4 weeks and 1320 ± 364 g, respectively. The median (interquartile range) age of onset of illness was 7 (5-12) days. The overall mortality rate was 23.8%, and among survivors, 50% had neurologic complications requiring intervention. Vancomycin and ciprofloxacin were the most used antibiotics for treatment in our series, with a median duration of 26 (17-38) days. On univariate analysis, shock at presentation was significantly associated with increased mortality (P = 0.04) while, seizures (P = 0.04) and elevated cerebrospinal fluid protein levels (P = 0 .01) at onset of illness predicted progressive hydrocephalus in surviving neonates.
CONCLUSIONS: E. meningoseptica sepsis is associated with high morbidity and mortality. Early diagnosis and prompt initiation of appropriate antibiotics are critical for improving survival and neurodevelopmental outcomes. Though isolation of the organism by environmental surveillance is always not possible, with proper infection control measures, the infection can be controlled.

Liver injuries caused by various industrial chemicals represent a serious health concern worldwide. Flexirubins are a novel class of naturally occurring bacterial pigments whose bioactivity remains largely unexplored. The present study evaluated the hepatoprotective effects of flexirubin pigment extracted from the bacterium Chryseobacterium artocarpi against CCl4-induced acute liver injury in mice. Flexirubin was applied at three different oral doses, 125, 250 and 500 mg/kg bw/d for seven consecutive days. Treatment of animals with flexirubin before exposure to CCl4 (10 mL/kg bw dissolved in olive oil, 1:1 v/v) significantly decreased the elevated serum levels of ALT, AST, ALP, LDH and TBL. Flexirubin pretreatment showed a great capability for attenuating the CCl4-induced oxidative stress by decreasing the level of liver MDA, and increasing the antioxidant enzyme activities of liver SOD and CAT, and the levels of GSH and TAC. Flexirubin also alleviated the histopathological alterations in liver by prohibiting steatosis, ballooning degeneration, leukocytic infiltration and necrosis. Immunohistochemical analysis demonstrated that flexirubin has a significant anti-apoptotic activity against CCl4 via upregulation of Bcl-2, and downregulation of Bax, Caspase-3 and TGF-β1. Flexirubin also exhibited a remarkable anti-inflammatory activity against CCl4 through its suppressive action on TNF-α, COX-2 and CD-45. Flexirubin could trigger upregulation of the Nrf2/HO-1 signaling pathway mediating protection against CCl4. In silico molecular docking revealed flexirubin as a potential inhibitor against two target proteins, TGF-β1 and TACE. The results proved the effectiveness of flexirubin as a significant source of natural compounds for its use in drug formulation strategies to offer protection against hepatotoxins.

For the local health service, Elizabethkingia meningoseptica remains a relatively new and little-known pathogen, whereas in many countries of Europe, Asia and other continents it is considered as a potential causative agent of nosocomial infections, especially in premature infants and immunocompromised patients. An analysis of the literature data, as well as our results indicate that E. meningoseptica should be considered as a potential pathogen, which is characterized by a unique profile of susceptibility to antimicrobial agents (AMP) and disinfectants. This article presents the results of a study of susceptibility to AMP and disinfectants of three isolates of E. meningoseptica, isolated during an investigation of an outbreak in one of the perinatal centers of the Russian Federation, where three cases of sepsis with a fatal outcome in premature infants caused by co-infection with Acinetobacter baumannii and E. meningoseptica were recorded between January and February 2016.

The current research is focused on studying the biological efficacy of flexirubin, a pigment extracted from Chryseobacterium artocarpi CECT 8497.Different methods such as DPPH, H2O2, NO•, O2•-, •OH, lipid peroxidation inhibition by FTC and TBA, ferric reducing and ferrous chelating activity were carried out to evaluate the antioxidant activity of flexirubin. Molecular docking was also carried out, seeking the molecular interactions of flexirubin and a standard antioxidant compound with SOD enzyme to figure out the possible flexirubin activity mechanism. The new findings revealed that the highest level of flexirubin exhibited similar antioxidant activity as that of the standard compound according to the H2O2, •OH, O2•-, FTC and TBA methods. On the other hand, flexirubin at the highest level has shown lower antioxidant activity than the positive control according to the DPPH and NO• and even much lower when measured by the FRAP method. Molecular docking showed that the interaction of flexirubin was in the binding cavity of the SOD enzyme and did not affect its metal-binding site. These results revealed that flexirubin has antioxidant properties and can be a useful therapeutic compound in preventing or treating free radical-related diseases.

The occurrence of manganese in groundwater causes coloured water and pipe rusting in water treatment systems. Consumption of manganese-contaminated water promotes neurotoxicity in humans and animals. Manganese-oxidizing bacteria were isolated from contaminated areas in Thailand for removing manganese from water. The selected bacterium was investigated for its removal kinetics and mechanism using synchrotron-based techniques. Among 21 isolates, Streptomyces violarus strain SBP1 (SBP1) was the best manganese-oxidizing bacterium. At a manganese concentration of 1 mg L-1, SBP1 achieved up to 46% removal. The isolate also successfully removed other metal and metalloid, such as iron (81%) and arsenic (38%). The manganese concentration played a role in manganese removal and bacterial growth. The observed self-substrate inhibition best fit with the Aiba model. Kinetic parameters estimated from the model, including a specific growth rate, half-velocity constant, and inhibitory constant, were 0.095 h-1, 0.453 mg L-1, and 37.975 mg L-1, respectively. The synchrotron-based techniques indicated that SBP1 removed manganese via combination of bio-oxidation (80%) and adsorption (20%). The study is the first report on biological manganese removal mechanism using synchrotron-based techniques. SBP1 effectively removed manganese under board range of manganese concentrations. This result showed the potential use of the isolate for treating manganese-contaminated water.

Despite years of research, the glycome of the model nematode Caenorhabditis elegans is still not fully understood. Certainly, data over the years have indicated that this organism synthesizes unusual N-glycans with a range of galactose and fucose modifications on the Man2-3GlcNAc2 core region. Previously, up to four fucose residues were detected on its N-glycans, despite these lacking the fucosylated antennae typical of many other eukaryotes; some of these fucose residues are capped with hexose residues as shown by the studies of us and others. There have, though, been contrasting reports regarding the maximal number of fucose substitutions in C. elegans, which in part may be due to different methodological approaches, including use of either peptide:N-glycosidases F and A (PNGase F and A) or anhydrous hydrazine to cleave the N-glycans from glycopeptides. Here we compare the use of hydrazine with that of a new enzyme (rice PNGase Ar) and show that both enable release of glycans with more sugar residues on the proximal GlcNAc than previously resolved. By use of exoglycosidase sequencing, in conjunction with high-performance liquid chromatography (HPLC) and matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS), we now reveal that actually up to five fucose residues modify the core region of C. elegans N-glycans and that the α1,3-fucose on the reducing terminus can be substituted by an α-linked galactose. Thus, traditional PNGase F and A release may be insufficient for release of the more highly core-modified N-glycans, especially those occurring in C. elegans, but novel enzymes can compete against chemical methods in terms of safety, ease of cleanup, and quality of resulting glycomic data.

Elizabethkingia meningoseptica is an infrequent cause of hospital-acquired infections. The clinical and microbiological profiles of infections due to E. meningoseptica over a seven-year period at a Level-I trauma centre are reported in this study. Medical records of patients from whose clinical samples E. meningoseptica was isolated on more than one occasion were reviewed. A total of 21 cases were observed during the study, 16 (76.2%) of which exhibited multidrug resistance. The observed in-hospital mortality rate was 47.6%. A high index of clinical suspicion and effective detection of E. meningoseptica in clinical samples are requisite for improved clinical outcome.

The taxonomic classification of 182 phenotypically similar isolates was evaluated using DNA-DNA hybridization and 16S rRNA gene sequence analysis. These bacterial isolates were mainly derived from clinical sources; all were Gram-negative non-fermenters and most were indole-producing. Phenotypically, they resembled species from the genera Chryseobacterium, Elizabethkingia or Empedobacter or belonged to CDC groups IIc, IIe, IIh and IIi. Based on these analyses, four novel species are described: Chryseobacterium bernardetii sp. nov. (type strain NCTC 13530(T) = CCUG 60564(T) = CDC G229(T)), Chryseobacterium carnis sp. nov. (type strain NCTC 13525(T) = CCUG 60559(T) = CDC G81(T)), Chryseobacterium lactis sp. nov. (type strain NCTC 11390(T) = CCUG 60566(T) = CDC KC1864(T)) and Chryseobacterium nakagawai sp. nov. (type strain NCTC 13529(T) = CCUG 60563(T) = CDC G41(T)). The new combination Chryseobacterium taklimakanense comb. nov. (type strain NCTC 13490(T) = X-65(T) = CCTCC AB 208154(T) = NRRL B-51322(T)) is also proposed to accommodate the reclassified Planobacterium taklimakanense.

Members of most Chryseobacterium species occur in aquatic environments or food products, while strains of some other species are pathogenic to humans and animals. A collection of 52 Chryseobacterium sp. strains isolated from diseased fish, one frog isolate and 22 reference strains were included in a polyphasic taxonomy study. Fourteen clusters of strains were delineated following the comparison of whole-cell protein profiles. Most of these clusters were confirmed when the phenotypic and RAPD profiles and the 16S rRNA gene sequences were compared. Fatty acid composition helped differentiate the Chryseobacterium strains from members of related genera. None of the fish isolates could be allocated to the two species previously reported from fish but two isolates belonged to C. joostei, while the frog isolate was identified as Elizabethkingia meningoseptica, a human pathogen previously included in the genus Chryseobacterium. Three clusters grouping from 3 to 13 isolates will probably constitute the core of new Chryseobacterium species but all other isolates occupied separate or uncertain positions in the genus. This study further demonstrated the overall high similarity displayed by most Chryseobacterium strains whatever the technique used and the resulting difficulty in delineating new species in the genus. Members of this bacterial group should be considered potential emergent pathogens in various fish and frog species, farming conditions and geographical areas.