Herbal medicine contains hundreds of natural products, and studying their absorption, metabolism, distribution, and elimination presents great challenges. Gelsemium elegans (G. elegans) is a ...flowering plants in the Loganiaceae family. The plant is known to be toxic and has been used for many years as a traditional Chinese herbal medicine for the treatment of rheumatoid arthritis, neuropathic pain, spasticity, skin ulcers and cancer. It was also used as veterinary drugs for deworming, promoting animal growth, and pesticides. At present, studies on the metabolism of G. elegans have primarily focused on only a few single available reference ingredients, such as koumine, gelsemine and gelsedine.
The goal of this work is to elucidate the overall metabolism of whole G. elegans powder in goats using high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC/QqTOF-MS).
Analyses of plasma, urine and fecal samples identified or tentatively characterized a total of 44 absorbed natural products and 27 related produced metabolites. Gelsedine-type, sarpagine-type and gelsemine-type alkaloids were the compounds with the highest metabolite formation. In the present study, most natural products identified in G. elegans were metabolized through glucuronidation and oxidation. Hydrogenation, dehydrogenation and demethylation also occurred.
To our knowledge, this is the first report of the metabolite profiling of the G. elegans crude extract in goats, which is of great significance for a safer and more rational application of this herbal medicine.
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The concentrations, congener profiles and spatial distribution of 13 phthalate esters (PAEs) in the freshwater fish ponds in the Pearl River Delta (PRD) region were investigated in water and sediment ...samples collect from 22 sites during Jul. 2016–Sept. 2017. The di-2-ethylhexyl phthalate (DEHP) was the predominant compounds in both water and sediment samples, accounting for 70.1% and 66.1% of ∑PAEs, respectively. The DEHP concentrations in the water samples collected from the sites of Zhongshan (35.7 μg/L), Jingmen (17.3 μg/L) and Nanhai (14.2 μg/L) were higher than that collected from other sampling sites (p <0.05), and exceed the Chinese environmental quality standards for surface water (DEHP, 8.00 μg/L). The concentrations of ΣPAEs (mean and median were 11.8 mg/kg dw and 7.95 mg/kg dw) in sediment was higher than that in sediment of river and estuary in the PRD region (p <0.05). The median concentrations of DEHP and di-n-butyl phthalate (DBP) exceeded recommend environmental risk limit (ERL) that posed a potential risk to the aquaculture fish pond environment in the PRD.
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•Phthalate esters were determined in the aquaculture fish ponds of PRD.•DEHP was the predominant compounds in the fish ponds.•DEHP content in the water sample exceeded the local environmental quality standard.•The DEHP and DBP exceeded a recommend environmental risk limit.
Cassava starch is a widely used raw material for industrial production. South Chinese cassava cultivar 8 (Manihot esculenta Crantz cv. SC8) is one of the main locally planted cultivars. In this ...study, an efficient transformation system for cassava SC8 mediated with Agrobacterium strain LBA4404 was presented for the first time. Cassava friable embryogenic calli (FECs) were transformed through the binary vector pCAMBIA1304 harboring GUS- and GFP-fused genes driven by the CaMV35S promoter. The transformation efficiency was increased in the conditions of Agrobacterium strain cell infection density (OD600 = 0.65), 250 µM acetosyringone induction, and agro-cultivation with wet FECs for 3 days in dark. Based on the optimized transformation protocol, approximately 120–140 independent transgenic lines per mL settled cell volume (SCV) of FECs were created by gene transformation in approximately 5 months, and 45.83% homozygous mono-allelic mutations of the MePDS gene with a YAO promoter-driven CRISPR/Cas9 system were generated. This study will open a more functional avenue for the genetic improvement of cassava SC8.
This study aimed to investigate the prevalence and genomic characteristics of the colistin resistance gene
in Salmonella enterica in China. In total, 445 S. enterica isolates from animals and food ...products were screened through PCR and sequencing for the presence of
. The
genes were detected in nine Salmonella strains (2.02%), with complete
in S. enterica serovar Indiana (
= 1) and an
Typhimurium monophasic variant (
4,5,12:i:-;
= 1),
in S. enterica serovar London (
= 1), and an incomplete
in
. Indiana (
= 6). They exhibited MIC values of 0.25 to 8 mg/L to colistin and showed resistance to multiple antimicrobial agents. Whole-genome sequencing was performed on
-positive Salmonella strains using Illumina HiSeq or PacBio single-molecule real-time sequencing. The complete
gene was located on conjugative IncN1-IncHI2 plasmid and IncX4 plasmid, respectively, with high similarity to other
-bearing plasmids belonging to the same incompatibility type. Together with an additional 13 antimicrobial resistance genes, the incomplete
was embedded in an 81,442-bp multiresistance region on the chromosome in
. Indiana YZ20MCS6. The Δ
segment and a set of tellurite resistance determinants (
) in six
. Indiana strains were similar to other IncHI2 plasmid backbones. The
gene was located on an untyped plasmid pYULZMPS10. Although low prevalence of
was observed in Salmonella, continuous surveillance of this gene in Salmonella is required. Plasmids play an important role in
transmission, and
, although incomplete, can be captured by chromosomes with the help of mobile elements.
Colistin is a last-resort antibiotic for severe infections caused by multidrug-resistant (MDR) Gram-negative pathogens. Colistin resistance genes
, particularly
, have been found in
around the world, mainly in Escherichia coli and Salmonella. Salmonella enterica is a major foodborne pathogen, with MDR Salmonella being considered a "Serious Threat Level pathogen" by the Centers for Disease Control and Prevention. Therefore, the prevalence of
in Salmonella strains must be monitored. In this study, a low
prevalence (2.02%) was observed in Salmonella strains from animals and food products, with plasmid-borne
in S. enterica serovar Indiana and an
Typhimurium monophasic variant (
4,5,12:i:-) and chromosomally located
in
Indiana. The
gene was first identified in S. enterica serovar London associated with an untyped plasmid. Although this study reports a low
prevalence in Salmonella, the transmission ability of
-positive Salmonella strains to humans via the food chain is a public health concern.
► An efficient MILT-MHD method was first developed for isolation of essential oil. ► Optimization and modeling the method by response surface design and kinetics. ► Procedure benefits: higher yield, ...shorter duration and more valuable constituents. ► Samples before and after treatment were characterized by SEM and FTIR spectra. ► A potential and green separation technique for the fragrance and flavor industries.
With the strong dissolution ability to biomaterials, ionic liquids can lead to a better release of the active and valuable ingredients embedded in plant matrices. Accordingly, an integrated microwave-assisted ionic liquids treatment followed by hydro-distillation (MILT-MHD) for isolating the essential oil from Fructus forsythiae seed was first performed in the present study. 1-ethyl-3-methylimidazolium acetate (C2mimOAc) was selected as the optimal ionic liquid. Operational conditions of this novel technique were optimized by the response surface methodology (RSM) and first order kinetic model. Compared with the conventional hydro-distillation (HD) and the emerging microwave-assisted aqueous ionic liquids hydro-distillation (MAILHD), the innovative MILT-MHD provided the remarkable advantage of much higher yield of essential oil (9.58%) within much shorter extraction duration (29.3min) than those of HD (4.08% and 100min) and MAILHD (5.43% and 45min). Additionally, GC–MS results showed that higher contents of valuable oxygenated monoterpenes were existed in the essential oil obtained by MILT-MHD (22.79%) than those by HD (16.57%) and MAILHD (19.84%). Furthermore, SEM and FTIR results illustrated the severe structural disruption of seed samples by MILT-MHD. Therefore, the present results demonstrated that MILT-MHD is a potential, green and highly efficient technique for the extraction of volatile fractions from aromatic plant materials in the fragrance and flavor industries.
Alkaline/neutral invertase (A/N-INV) is an invertase that irreversibly decomposes sucrose into fructose as well as glucose and plays a role in plant growth and development, starch synthesis, abiotic ...stress, and other plant-life activities. Cassava is an economically important starch crop in tropical regions. During the development of cassava tuber roots, A/N-INV activity is relatively high, which indicates that it may participate in sucrose metabolism and starch synthesis. In this study, MeNINV1 was confirmed to function as invertase to catalyze sucrose decomposition in yeast. The optimal enzymatic properties of MeNINV1 were a pH of 6.5, a reaction temperature of 40 °C, and sucrose as its specific catalytic substrate. VB
, Zn
, and Pb
at low concentrations as well as EDTA, DTT, Tris, Mg
, and fructose inhibited A/N-INV enzymic activity. In cassava, the
gene was mainly expressed in the fibrous roots and the tuber root phloem, and its expression decreased as the tuber root grew. MeNINV1 was confirmed to localize in chloroplasts. In
,
-overexpressing
had higher A/N-INV activity, and the increased glucose, fructose, and starch content in the leaves promoted plant growth and delayed flowering time but did not change its resistance to abiotic stress. Our results provide new insights into the biological function of MeNINV1.
To explore the clinical characteristics and etiology of bacterial meningitis (BM) in Chinese children.
BM cases in children 28days to 18 years old were collected from January 2014–December 2016 and ...screened according to World Health Organization standards. Clinical features, pathogens, and resistance patterns were analyzed.
Overall, 837 cases were classified into five age groups: 28 days–2 months (17.0%), 3–11 months (27.8%), 12–35 months (24.0%), 3–6 years (13.9%), and >6years (17.3%). Major pathogens were Streptococcus pneumoniae (S. pneumoniae, n=136, 46.9%), group B Streptococcus (GBS, n=29, 10.0%), and Escherichia coli (E. coli, n=23, 7.9%). In infants <3 months old, GBS (46.5%) and E. coli (23.3%) were most common; in children >3 months old, S. pneumoniae (54.7%), which had a penicillin non-susceptibility rate of 55.4% (36/65), was most frequent. The resistance rates of S. pneumoniae and E. coli to cefotaxime and ceftriaxone were 14.0%/40.0% and 11.3%/68.4%, respectively. All GBS isolates were sensitive to penicillin.
The occurrence of BM peaked in the first year of life, while S. pneumoniae was the predominant pathogen in children >3months of old. The antibiotic resistance of S. pneumoniae was a concern.
In microalgae, the lipid accumulation under nitrogen stress is always accompanied by low photosynthetic activity and low growth rate, which adversely affects the total biomass and the lipid ...productivity. It is highly desirable to develop a practicable strategy for promoting lipid accumulation meanwhile minimizing the adverse effects under nitrogen stress. In this research, we investigate whether melatonin (MT, an antioxidant that protects against abiotic stress in plant cells) can mitigate the oxidative stress and enhance the lipid production in Chlamydomonas reinhardtii starchless mutants under nitrogen stress. The results of physiological and biochemical analysis indicate that exogenous MT weakens the nitrogen stress-induced oxidative damage by delaying the chlorophyll loss, activating antioxidases, reducing the lipid peroxidation. In addition, MT stimulates the biosynthesis of functional membrane lipids (monogalactosyldiacylglycerol, digalactosyldiacylglycerol and diacylglyceryl-trimethylhomoserine) and polyunsaturated fatty acids, increasing the cell response to nitrogen stress and enhancing the whole lipid biosynthesis. The 5 μM MT induces the increase of the total fatty acid methyl ester-lipid content by 35.4% (from 49.2% to 66.7% of dry weight), the biomass by 7.4% (to 0.92 g L−1), and the lipid productivity by 42.7% compared with the control groups without MT treatment. Moreover, we investigated the biodiesel properties of the lipids derived from MT-treated nitrogen-stressed cells, and the results suggest that the variation in fatty acid proportion induced by MT has little impact on the lipid's biodiesel properties. Thus, exogenous MT can facilitate the accumulation of lipids by enhancing the cellular antioxidant capability and mitigating the adverse effects of nitrogen stress.
•Melatonin stimulates the biosynthesis of functional membrane lipids and polyunsaturated fatty acids.•The 5 μM melatonin induces the increase of nitrogen-stressed fatty acid methyl esters-lipid content from 49.2% to 66.7%.•We investigated the biodiesel properties of the lipids after melatonin treatment.
This study aimed to investigate the prevalence and diversity of extended-spectrum β-lactamases (ESBL)-producing
Escherichia coli
isolates from healthy individuals in a community and to elucidate ...their dissemination mechanism. Cefotaxime-resistant
E. coli
were isolated from 95 samples of healthy persons from one community in Yangzhou, China, and were tested for minimal inhibitory concentrations of 14 antimicrobial agents. The isolates were subjected to whole genome sequencing by Illumina Hiseq or PacBio single-molecule real-time sequencing. A total of 30 cefotaxime-resistant
E. coli
isolates were obtained, carrying
bla
CTX-M
(n=29) or
bla
DHA
(n=1), of which the
bla
CTX-M-55
(n=19) was the most predominant genotype. One novel
bla
CTX-M
variant
bla
CTX-M-252
was identified. Thirteen CTX-M-55-producing
E. coli
isolates belonged to ST8369 from nasal (n=12) or faecal (n=1) samples shared the identical cgMLST type, resistance profiles, resistance genes, plasmid replicons, and a 5,053-bp
bla
CTX-M-55
structure ΔIS
26
-ΔIS
Ecp1
-
bla
CTX-M-55
-Δ
orf477
-ΔTn
2
. The
bla
CTX-M-55
gene was located on IncHI2/ST3 plasmid in
E. coli
ST8369. The lengths of
bla
CTX-M
/
bla
DHA
-carrying contigs in the remaining 17
E. coli
strains ranged from 1,663 to 382,836 bp, located on chromosome (n=4) or plasmids (n=5); the location of the other eight contigs could not be determined due to incomplete assembly. The
bla
CTX-M
was associated with IS
Ecp1
as previously reported. Nasal colonization of CTX-M-55-producing ST8369
E. coli
strains has occurred among healthy individuals in one community. There is a potential risk of antimicrobial resistance dissemination between humans within one community through close contact or environment
via
aerosols or dust. Therefore, surveillance of nasal carriage of
bla
CTX-M
in communities is warranted to further monitor the spread of the antimicrobial resistance genes in China.
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