Fucoxanthin restructures the gut microbiota and metabolic functions of non-obese individuals in an in vitro fermentation model.

Fucoxanthin, a carotenoid exclusively derived from algae, exerts its bioactivities with the modulation of the gut microbiota in mice. However, mechanisms through which fucoxanthin regulates the gut microbiota and its derived metabolites/metabolism in humans remain unclear. In this study, we investigated the effects of fucoxanthin on the gut microbiota and metabolism of non-obese individuals using an in vitro simulated digestion-fermentation cascade model. The results showed that about half of the fucoxanthin was not absorbed in the intestine, thus reaching the colon. The gut microbiota from fecal samples underwent significant changes after 48 or 72 hours in vitro fermentation. Specifically, fucoxanthin significantly enhanced the relative abundance of Bacteroidota and Parabacteroides, leading to improved functions of the gut microbiota in its development, glycan biosynthesis and metabolism as well as in improving the digestive system, endocrine system and immune system. The recovery of fucoxanthin during fermentation showed a decreasing trend with the slight bio-conversion of fucoxanthinol. Notably, fucoxanthin supplementation significantly altered metabolites, especially bile acids and indoles in the simulated human gut ecosystem. Correlation analysis indicated the involvement of the gut microbiota in the manipulation of these metabolites by fucoxanthin. Moreover, all these altered metabolites revealed the improvement in the capacity of fucoxanthin in manipulating gut metabolism, especially lipid metabolism. Overall, fucoxanthin determinedly reshaped the gut microbiota and metabolism, implying its potential health benefits in non-obese individuals.

Fungal Selectivity and Biodegradation Effects by White and Brown Rot Fungi for Wood Biomass Pretreatment.

The biodegradation path and mechanism of wood varies depending on diverse fungi and tree species, as fungi possess selectivity in degradation of versatile wood components. This paper aims to clarify the actual and precise selectivity of white and brown rot fungi and the biodegradation effects on different tree species. Softwood (Pinus yunnanensis and Cunninghamia lanceolata) and hardwood (Populus yunnanensis and Hevea brasiliensis) were subjected to a biopretreating process by white rot fungus Trametes versicolor, and brown rot fungi Gloeophyllum trabeum and Rhodonia placenta with various conversion periods. The results showed that the white rot fungus Trametes versicolor had a selective biodegradation in softwood, which preferentially convert wood hemicellulose and lignin, but cellulose was retained selectively. Conversely, Trametes versicolor achieved simultaneous conversion of cellulose, hemicellulose and lignin in hardwood. Both brown rot fungi species preferentially converted carbohydrates, but R. placenta had a selectivity for the conversion of cellulose. In addition, morphological observation showed that the microstructures within wood changed significantly, and the enlarged pores and the improved accessibility could be beneficial for the penetration and accessibility of treating substrates. The research outcomes could serve as fundamental knowhows and offer potentials for effective bioenergy production and bioengineering of bioresources, and provide a reference for further application of fungal biotechnology.

Antibacterial Mechanism of Patrinia scabiosaefolia Against Methicillin Resistant Staphylococcus epidermidis.

Purpose: Staphylococcus epidermidis has become one of the most common causes of septicemia. Meanwhile, S. epidermidis has acquired resistance to many antibiotics. Among these, methicillin-resistant S. epidermidis (MRSE) were frequently isolated. Similar to methicillin resistant Staphylococcus aureus (MRSA), they also exhibited multi-resistance, which presented a danger to human health. Patrinia scabiosaefolia as traditional Chinese medicine had strong antibacterial activity against MRSE. However, the mechanism of P. scabiosaefolia against MRSE is not clear. Methods: Here, the morphology of cell wall and cell membrane, production of ß-lactamase and PBP2, energy metabolism, antioxidant system were systematically studied. Results: The data showed that P. scabiosaefolia damaged the cell wall and membrane. In addition, ß-lactamase, energy metabolism and antioxidant system were involved in mechanisms of P. scabiosaefolia against MRSE. Conclusion: These observations provided new understanding of P. scabiosaefolia against MRSE to control MRSE infections.

Eco-Friendly Wood Composites: Design, Characterization and Applications.

The ongoing transition from a linear to a circular, low-carbon bioeconomy is crucial for reducing the consumption of global natural resources, minimizing waste generation, reducing carbon emissions, and creating more sustainable growth and jobs, the prerequisites necessary to achieve climate neutrality targets and stop biodiversity loss [...].

First report of Phytophthora blight caused by Phytophthora nicotianae on Daphne odora in China.

The variegated leaves and fragrant flowers of Daphne odora var. marginata Mak. make it a popular garden plant. In May 2020, we found diseased D. odora plants in a greenhouse at the Ganzhou Vegetable and Flower Research Institute, in southeast China; 72% of 1800 plants had Phytophthora blight-like symptoms-shrunken stems, black withered branches, wilted and dropped leaves (Fig 1a), and rotted and dark green roots. The root and stem tissue surfaces were disinfected with 75% ethanol for 30 s followed by 0.1% HgCl2 for 1 min, rinsed thrice with sterile water, and cultured on potato-dextrose agar (PDA) medium at 25°C. Mycelia from the diseased tissue were subcultured on fresh PDA medium, providing three colonies. White colonies (~4.1 mm) were formed after 10 days at 25°C (Fig 1b). Sporangia and chlamydospores were induced by placing actively growing mycelia on PDA medium at 25°C for ~30 days and then at 45°C for ~3 days. Sporangia were ovoid to spherical and 19.33 × 20.99 µm in size (Fig 1c), whereas chlamydospores were spherical and 15.68 × 16.10 µm in size (Fig 1d). All three colonies resembled Phytophthora spp. Genomic DNA was extracted from isolates using the Ezup Column Fungi Genomic DNA Purification Kit (Sangon Biotech [Shanghai] Co. Ltd.), and rDNA-ITS and ß-tubulin were amplified and sequenced. BLAST analysis (GenBank) revealed that the ITS (Accession No. MZ676071) and ß-tubulin (MZ748503) sequences of isolates shared the highest similarity (99-100%) with those of Phytophthora nicotianae (Duccio et al. 2015). A phylogenetic tree of the relationship between our isolate hjt3 and its close relatives within the P. nicotianae species was constructed using the MEGA X neighbor-joining method (Fig 2). The pathogen was identified as P. nicotianae based on morphological and molecular characteristics. Sequencing results of the three samples were consistent, all indicating P. nicotianae. A specimen (JXAU-H2020245) was deposited in the Herbarium of the College of Agronomy, Jiangxi Agricultural University. To confirm pathogenicity, 9-month-old healthy D. odora plants were used for stem and soil inoculation. Stems were cut ~5 cm from the soil with sterilized scalpels and inoculated with 0.8 cm diameter PDA plugs containing actively growing mycelia of isolate hjt3. The soil was sterilized and 0.8 cm PDA plugs containing actively growing mycelia were buried in the soil at ~5 cm; the mycelia were in contact with the roots. Plants in both groups were treated equally; those inoculated with sterile PDA plugs served as controls. There were six plants in each group, with each experiment performed in triplicate. All plants were incubated in a greenhouse at 25-28°C. The stems shrank and began to rot rapidly after 7 days (Fig 3) and the branches turned black and withered within 2 weeks. After soil inoculation, the stems of the inoculated plants blackened and rotted in ~20 days (Fig 4) and the roots rotted and turned dark green (Fig 5). These symptoms rapidly spread to the branches. The control plants did not exhibit any symptoms. Reisolated colonies showed the same morphological traits as the isolates used for inoculation; no target colonies were isolated from the control plants. Phytophthora blight caused by P. nicotianae on D. odora has been reported in Italy (Garibaldi A, 2009) and Korea (Kwon et al. 2005). This is the first detection in China. Therefore, Phytophthora blight on D. odora caused by P. nicotianae should be monitored and controlled to promote the development of the D. odora industry.

Molecular Mechanism of Staphylococcus xylosus Resistance Against Tylosin and Florfenicol.

Purpose: Drug resistance presents an ever-increasing global public health threat that involves all major microbial pathogens and antimicrobial drugs. Strains that are resistant to multiple drugs pose severe clinical problems and cost lives. However, systematic studies on cross-resistance of Staphylococcus xylosus have been missing. Methods: Here, we investigated various mutations in the sequence of ribosomal proteins involved in cross-resistance. To understand this effect on a molecular basis and to further elucidate the role of cross-resistance, we computationally constructed the 3D model of the large ribosomal subunit from S. xylosus as well as its complexes with both tylosin and florfenicol. Meanwhile, all-atom molecular dynamics simulations was used. In addition, the regulation of protein networks also played an essential role in the development of cross-resistance in S. xylosus. Results: We discovered that the minimum inhibitory concentration against both tylosin and florfenicol of the mutant strain containing the insertion L22 97KRTSAIN98 changed dramatically. Further, we found that unique structural changes in the ß-hairpin of L22 played a central role in this variant in the development of antibiotic resistance in S. xylosus. The regulation of protein networks also played an essential role in the development of cross-resistance in S. xylosus. Conclusion: Our work provides insightful views into the mechanism of S. xylosus resistance that could be useful for the development of the next generation of antibiotics.

Biomass-based hydrogels with high ductility, self-adhesion and conductivity inspired by starch paste for strain sensing.

Currently, hydrogel sensors for health monitoring require external tapes, bandages or adhesives to immobilize them on the surface of human skin. However, these external fixation methods easily lead to skin allergic reactions and the decline of monitoring accuracy. A simple strategy to solve this problem is to endow hydrogel sensors with good adhesion. Inspired by the starch paste adhesion mechanism, a biomass-based hydrogel with good conductivity and high repetitive adhesion strength was prepared by introducing modified starch into polyacrylic acid hydrogel system. The properties of biomass-based hydrogels could be controlled by changing the proportion of amylose and amylopectin. The biomass-based hydrogel exhibited a variety of excellent properties, including good stretchability (1290 %), high adhesion strength (pig skin: 46.51 kPa) and conductivity (2.3 S/m). Noticeably, the repeated adhesive strength of biomass-based hydrogel did not decrease with the increase of adhesion times. The strain sensor based on the biomass-based hydrogel could accurately monitor the large-scale and small movements of the human body, and had broad application prospects in the field of flexible wearable devices.

Polyionic liquids supramolecular hydrogel with anti-swelling properties for underwater sensing.

The preparation of hydrogel-based wearable sensors for underwater application with high mechanical properties and electrical conductivity is an urgent challenge. Here, a supramolecular hydrogel based on polyionic liquids was designed and prepared for underwater sensing. The introduction of functional ionic liquid structures effectively increased the supramolecular interaction in the hydrogel network, which made the hydrogel successfully resist the interference of external water molecules. Depending on the effect of charge and hydrophobic interactions, this supramolecular hydrogel sensor exhibited high tensile (759 %), high tensile strength (0.23 MPa), high sensitivity (GF = 10.76) and extensive antibacterial properties, even in seawater environment. The obtained hydrogel sensor successfully monitored the swimming posture, which was helpful to digitally reflect the limb movement of athletes during underwater sports. This work made progress in the field of underwater wearable sensors based on hydrogels, and this design of multifunctional hydrogel provided a new idea for the development of functional sensors.

Pressure evolution of electronic and structural properties in transition metal dichalcogenide 1T-Co1.06Te2.

Two-dimensional transition metal dichalcogenides (TMDs) are important materials for promising electronic devices because they usually exhibit excellent and highly tunable electronic properties. Here, we report on the pressure-driven electronic phase transition in a TMD 1T-Co1.06Te2. High-pressure transport measurements reveal a sign reversal of the Hall coefficients at a critical point ofPC∼ 32 GPa, evidencing a transition from hole band(s) dominated transport into one that is dominated by electron band(s). Synchrotron x-ray diffraction experiments demonstrate that no structural phase transition occurs below 46.3 GPa, indicating an electronic origin of the transition. Moreover, a kink anomaly of the lattice constant ratioc/ais also observed atP=PC. These results might indicate a Lifshitz transition which refers to a change of Fermi surface topology in absence of structural transition.

Comparative Proteomic Analysis Reveals Antibacterial Mechanism of Patrinia scabiosaefolia Against Methicillin Resistant Staphylococcus epidermidis.

Purpose: As a kind of opportunist pathogen, Staphylococcus epidermidis (MRSE) can cause nosocomial infections and easily evolve into resistant bacteria. Among these, methicillin-resistant Staphylococcus epidermidis (MRSE) exhibit significantly higher rates. Our previous study showed that Patrinia scabiosaefolia (PS) possessed strong antibacterial activity against MRSE. However, the mechanism of PS against MRSE is not clear. Methods: Here, a tandem mass tag-based (TMT) proteomic analysis was performed to elucidate the potential mechanism of PS against MRSE. We compared the differential expression proteins of MRSE under PS stress. Results: Based on a fold change of >1.2 or < 1/1.2 (with p value set at <0.05), a total of 248 proteins (128 up-regulated proteins, 120 down-regulated proteins) were identified. Bioinformatic analysis showed that proteins including arginine deiminase (arcA), ornithine carbamoyltransferase (arcB) and carbamate kinase (arcC), serine-tRNA ligase (serS), phenylalanine-tRNA ligase beta and subunit (pheT), DltD (dlt), d-alanyl carrier protein (dlt), accumulation-associated protein (SasG), serine-aspartate repeat-containing protein C (SdrC) and hemin transport system permease protein HrtB (VraG) played important roles in mechanism of PS against MRSE. Conclusion: In summary, these results indicated that arginine deiminase pathway (ADI) pathway, protein synthesis, cell wall synthesis, biofilm formation and uptake of iron were related to mechanisms of PS against MRSE. Our findings provide an insight into the the mechanism of PS against MRSE, and may be valuable in offering new targets to develop more anti-MRSE drugs.

A ionic liquid enhanced conductive hydrogel for strain sensing applications.

Strain-sensitive and conductive hydrogels have attracted extensive research interest due to their potential applications in various fields, such as healthcare monitoring, human-machine interfaces and soft robots. However, low electrical signal transmission and poor tensile properties still limit the application of flexible sensing hydrogels in large amplitude and high frequency motion. In this study, a novel ionic liquid segmental polyelectrolyte hydrogel consisting of acrylic acid (AAc), 1-vinyl-3-butylimidazolium bromide (VBIMBr) and aluminum ion (Al3+) was prepared by molecular design and polymer synthesis. The cationic groups and amphiphilicity of ionic liquid chain segments effectively improve the tensile behavior of the polyelectrolyte hydrogel, with a maximum tensile strength of 0.16 MPa and a maximum breaking strain of 604%. The introduction of ionic liquid segments increased the current carrying concentration of polyelectrolyte hydrogel, and the conductivity reached the initial 4.8 times (12.5 S/m), which is a necessary condition for detecting various amplitude and high frequency limb movements. The flexible electronic sensor prepared by this polyelectrolyte hydrogel efficiently detects the movement of different parts of the human body stably and sensitively, even in extreme environment (-20 °C). These outstanding advantages demonstrate the great potential of this hydrogel in healthcare monitoring and wearable flexible strain sensors.

Relationship between L-lactate dehydrogenase and multidrug resistance in Staphylococcus xylosus.

Staphylococcus xylosus is a gram-positive bacterium that has attracted much attention due to its increasing clinical appearance, frequently associated with serious multidrug resistance cases. L-lactate dehydrogenase (LDH) has been related to drug resistance in several bacterial species. However, the mechanism of multidrug resistance in S. xylosus remains unclear as well as the involvement of LDH in such resistance. To explore the relationship between multidrug resistance and LDH in S. xylosus, we used tylosin-resistant S. xylosus as the parent strain to construct ldh knockout and complemented strains. Then, we tested their resistance to macrolides, lincosamides, tetracyclines, and aminoglycosides. In addition, the enzyme activity, metabolite content, and transcriptional level of key genes involved in the TCA cycle and thioredoxin system were determined to clarify the mechanism of resistance. We observed that the resistance to multiple antibiotics increased significantly after ldh knockout, especially that to lincomycin, whereas antibiotic sensitivity was partially restored in the complemented strain. The levels of pyruvate, nicotinamide adenine dinucleotide, and reactive oxygen species decreased significantly upon ldh knockout, and the activity of isocitrate dehydrogenase and malate dehydrogenase decreased. These results indicate that the lack of LDH promotes multidrug resistance in S. xylosus by inhibiting the TCA cycle and regulating the thioredoxin system.

Lipid-Lowering Bioactivity of Microalga Nitzschia laevis Extract Containing Fucoxanthin in Murine Model and Carcinomic Hepatocytes.

Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis, is one of the most common liver diseases worldwide. So far, no definitive medical treatment has been established to treat NAFLD except for lifestyle medication. Nitzschia laevis extract (NLE), a microalgal extract rich in fucoxanthin, has been previously demonstrated to reduce bodyweight in high-fat-diet (HFD) C57BL/6J mice, indicating potential for prevention of NAFLD. In the present study, we investigated the lipid-lowering effects of NLE in HFD-induced steatosis murine model and palmitate-treated HepG2 cells. The results showed that NLE significantly lowered inguinal fat and attenuated hepatic steatosis in C57BL/6J mice. Especially, NLE significantly prevented lipid accumulation in HepG2 cells. This was probably due to its capability to enhance hepatic mitochondrial function as evidenced by the increased oxygen consumption rate (OCR) and mitochondrial membrane potential (MMP), and repress fatty acid synthesis through phosphorylation of acetyl-CoA carboxylase (ACC). Moreover, fucoxanthin was identified to be responsible for the lipid-lowering effect of NLE. Taken together, NLE or other microalgal fucoxanthin-rich products are promising natural products that may help prevent against NAFLD.

Interfacial structure and property of eco-friendly carboxymethyl cellulose/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) biocomposites.

This paper investigates the interface bonding of the novel carboxymethyl cellulose (CMC)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites, and the influence of coupling agents on the structure and properties of the biocomposites. The chemical structure, crystallisation behaviour and microstructure of the untreated and coupling agent treated biocomposites were examined by using FTIR, XRD and SEM respectively. The results suggested that maleic anhydride (MA) and vinyltrimethoxysilane (VTMS) covalently bonded to both CMC and PHBV macromolecules owing to their intrinsic multifunctionality, and promoted the distribution and embedment of the CMC in PHBV matrix, leading to a superior interfacial bonding of the resulted biocomposites. The enhanced interfacial bonding between the CMC and PHBV gave rise to a significant increase of tensile and flexural properties (i.e. tensile and flexural stress increased by up to 71% and 117% respectively, Young's and flexural modulus increased by up to 17% and 18% respectively) as well as thermal stability of the biocomposites.

Tylosin Inhibits Streptococcus suis Biofilm Formation by Interacting With the O-acetylserine (thiol)-lyase B CysM.

Streptococcus suis (S. suis) can decrease its virulence or modify local conditions through biofilm formation, which promotes infection persistence in vivo. Biofilm formation is an important cause of chronic drug-resistant S. suis infection. The aim of this study was to evaluate whether tylosin effectively inhibits S. suis biofilm formation by interacting with O-acetylserine (thiol)-lyase B (CysM), a key enzymatic regulator of cysteine synthesis. Biofilm formation of the mutant (ΔcysM) strain was significantly lower compared to the wild-type ATCC 700794 strain. Tylosin inhibited cysM gene expression, decreased extracellular matrix contents, and reduced cysteine, homocysteine, and S-adenosylmethionine levels, indicating its potential value as an effective inhibitor of S. suis biofilm formation. Furthermore, using biolayer interferometry technology and fourier-transform infrared spectroscopy, we found that tylosin and CysM could be combined directly. Overall, these results provide evidence that tylosin inhibits S. suis biofilm formation by interacting with CysM.

Non-hydrostatic pressure-dependent structural and transport properties of BiCuSeO and BiCuSO single crystals.

High-pressure experiments usually expect a hydrostatic condition, in which the physical properties of materials can be easily understood by theoretical simulations. Unfortunately, non-hydrostatic effect is inevitable in experiments due to the solidification of the pressure transmitting media under high pressure. Resultantly, non-hydrostaticity affects the accuracy of the experimental data and sometimes even leads to false phenomena. Since the non-hydrostatic effect is extrinsic, it is quite hard to analyze quantitatively. Here, we have conducted high pressure experiments on the layered BiCuXO (X = S and Se) single crystals and quantitatively analyzed their pronounced non-hydrostatic effect by high throughput first-principles calculations and experimental Raman spectra. Our experiments find that the BiCuXO single crystals sustain the tetragonal structure up to 55 GPa (maximum pressure in our experiment). However, their pressure-dependent Raman shift and electric resistance show anomalous behaviors. Through optimization of thousands of crystal structures in the high throughput first-principles calculations, we have obtained the evolution of the lattice constants under external pressures, which clearly substantiates the non-hydrostatical pressure exerted in BiCuXO crystals. Our work indicates that the high throughput first-principles calculations could be a handy method to investigate the non-hydrostatic effect on the structural and electronic properties of materials in high pressure experiments.

Long-Range Ordered Amorphous Atomic Chains as Building Blocks of a Superconducting Quasi-One-Dimensional Crystal.

Crystalline and amorphous structures are two of the most common solid-state phases. Crystals having orientational and periodic translation symmetries are usually both short-range and long-range ordered, while amorphous materials have no long-range order. Short-range ordered but long-range disordered materials are generally categorized into amorphous phases. In contrast to the extensively studied crystalline and amorphous phases, the combination of short-range disordered and long-range ordered structures at the atomic level is extremely rare and so far has only been reported for solvated fullerenes under compression. Here, a report on the creation and investigation of a superconducting quasi-1D material with long-range ordered amorphous building blocks is presented. Using a diamond anvil cell, monocrystalline (TaSe4 )2 I is compressed and a system is created where the TaSe4 atomic chains are in amorphous state without breaking the orientational and periodic translation symmetries of the chain lattice. Strikingly, along with the amorphization of the atomic chains, the insulating (TaSe4 )2 I becomes a superconductor. The data provide critical insight into a new phase of solid-state materials. The findings demonstrate a first ever case where superconductivity is hosted by a lattice with periodic but amorphous constituent atomic chains.

1-Hydroxyanthraquinone exhibited antibacterial activity by regulating glutamine synthetase of Staphylococcus xylosus as a virulence factor.

Staphylococcus xylosus (S. xylosus) is one of the emerging pathogens causing bovine mastitis with high rate of isolation in most of the reported clinical and field cases. To verify the role of glutamine synthetase (GS) in the pathogenesis of S. xylosus, we evaluated the virulence level of the wild-type strain and its glnA mutant strain in biofilm assays in vitro and murine infection model in vivo. From the results, it was observed that the glnA mutant strain was attenuated and could reduce tissue damage. 1-Hydroxyanthraquinone (1-HAQ) is a kind of anthraquinones, it exhibited a significant inhibitory effect on the growth of S. xylosus and biofilm formation in vitro and provided anti-inflammatory effects in vivo. In addition, the rate at which it inhibits the biofilm, inflammatory factors, and CFU of wild-type strains were significantly higher than that of the mutant strains, indicating that 1-hAQ might have pharmacological effects against S. xylosus through the regulation of GS protein. The effect of 1-hAQ on GS was further confirmed by the down-regulation of glnA expression, reduced GS activity, Gln content and the results of molecular docking. Taken together, these findings suggest that 1-hAQ facilitated a significant attenuation of S. xylosus pathogenicity by regulating the GS protein: a vital virulence factor. Therefore, it can be inferred that 1-hAQ may serve as a potential source of organic compound for the development of novel alternative drugs in mitigating the menace of bovine mastitis.

Integrating Benzenesulfonic Acid Pretreatment and Bio-Based Lignin-Shielding Agent for Robust Enzymatic Conversion of Cellulose in Bamboo.

A hydrotrope-based pretreatment, benzenesulfonic acid (BA) pretreatment, was used to fractionate bamboo in this work. With optimized content (80 wt %) of BA in pretreatment liquor, about 90% of lignin and hemicellulose could be removed from bamboo under mild conditions (95 °C, 30 min or 80 °C, 60 min). The potential accessibility of BA pretreated substrate to cellulase was thus significantly improved and was also found to be much higher than those of acidic ethanol and dilute acid pretreatments. But the deposition of lignin on the surface of solid substrates, especially the BA pretreated substrate, was also observed, which showed a negative effect on the enzymatic hydrolysis efficiency. The addition of inexpensive soy protein, a bio-based lignin-shielding agent, could readily overcome this negative effect, leading the increase of enzymatic conversion of cellulose in BA pretreated substrate from 37% to 92% at a low cellulase loading of 4 FPU/g glucan. As compared to acidic ethanol and dilute acid pretreatments, the combination of BA pretreatment and soy protein could not only stably improve the efficiency of non-cellulose components removal, but also could significantly reduce the loading of cellulase.

Analysis of multidrug resistance in Streptococcus suis ATCC 700794 under tylosin stress.

Streptococcus suis is an important zoonotic pathogen. The massive use of tylosin and other antibiotics in swine production has led to the emergence of resistant phenotypes of S. suis. However, there are no adequate measures available to address the problem of bacterial resistance. This study involved the use of 1/4 MIC (0.125 µg/mL) of tylosin to investigate resistance-related proteins by S. suis ATCC 700794. Our results showed that 171 proteins were differentially expressed in S. suis tested with 1/4 MIC (0.125 µg/mL) of tylosin using iTRAQ-based quantitative proteomic methods. TCS, heat shock protein and elongation factors were differentially expressed at 1/4 MIC (0.125 µg/mL) of tylosin compared to non treated, control cells. Using quantitative RT-PCR analysis, we verified the relationship between the differentially expressed proteins in S. suis with different MIC values. The data showed that expression profile for elongation factor G (fusA), elongation factor Ts (tsf), elongation factor Tu (tuf), putative histidine kinase of the competence regulon, ComD (comD), putative competence-damage inducible protein (cinA) and protein GrpE (grpE), observed in tylosin-resistant S. suis, correlated with that of S. suis ATCC 700794 at 1/4 MIC (0.125 µg/mL). The MIC of tylosin-resistant showed high-level resistance in terramycin, chlortetracycline, ofloxacin and enrofloxacin. Our findings demonstrated the importance of elongation factors, TCS and heat shock protein during development of tylosin resistance in S. suis. Thus, our study will provide insight into new drug targets and help reduce bacterial multidrug resistance through development of corresponding inhibitors.