Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced.At present,the control of P.nicotianae mainly depends on chemical methods,with considerable environmental and heal...Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced.At present,the control of P.nicotianae mainly depends on chemical methods,with considerable environmental and health issues.We investigated the effects of ethanol extracts from Scutellaria baicalensis Georgi(SBG)and Magnolia officinalis(MO).On mycelial growth,sporangium formation,and zoospore release of P.nicotianae.Both extracts inhibited the growth of P.nicotianae,with mycelial growth inhibition rates of 88.92%and 93.92%,respectively,at 40 mg/mL,and EC50 values of 5.39 and 5.74 mg/mL,respectively.The underlying mechanisms were the inhibition of sporangium formation,the reduction of zoospore number,and the destruction of the mycelium structure.At an SBG extract concentration of 16.17 mg/mL,the inhibition rates for sporangia and zoospores were 98.66%and 99.39%,respectively.At an MO extract concentration of 2.87 mg/mL,the production of sporangia and zoospores was completely inhibited.The hyphae treated with the two plant extracts showed different degrees of deformation and damage.Hyphae treated with SBG extract showed adhesion and local swelling,whereas treatment with MO extract resulted in broken hyphae.Mixture of the extracts resulted in a good synergistic effect.展开更多
Several of the fungal species associated with Fuzhuan brick tea(FBT)are considered as potential probiotics,but few studies have investigated the probiotic properties of these fungi.Here,we isolated 18 fungal strains f...Several of the fungal species associated with Fuzhuan brick tea(FBT)are considered as potential probiotics,but few studies have investigated the probiotic properties of these fungi.Here,we isolated 18 fungal strains from two types of FBT and identified these strains based on internal transcribed spacer(ITS)fragment sequence similarity to reference strains(sequence similarity>98%).Of the 18 strains,10 tolerated simulated human digestive conditions for sufficient periods in vitro:pH 2-3,0.3%-0.5%(m/V)bile salts,and artificial gastrointestinal juices.We then measured the antimicrobial activity of the remaining 10 strains against 5 enteropathogenic bacteria and tested the bacteriostatic effects of the thalli and fermentation broth extracts.Of the 6 strains with strong bacteriostatic effects,we eliminated Eurotium cristatum S-9 due to its low hydrophobicity of(26.12±0.35)%.Finally,2 exhibited good adhesion abilities to human cells(>100%).Notably,2 strains can survive in vivo,because they can be isolated from C57BL/6 mice feces.Thus,2 strains,Aspergillus cristatus H-1 and A.cristatus H-5,are herein identified as promising candidate probiotic strains.It may be put forward a novel research focus on evaluating potential probiotic fungi from FBT.展开更多
Taking salicylic acid as the active ingredient and 10%sodium hydroxide aqueous solution as the neutralizer,the best matrix for preparing gel was screened,and the salicylic acid aqueous gel was prepared.The properties,...Taking salicylic acid as the active ingredient and 10%sodium hydroxide aqueous solution as the neutralizer,the best matrix for preparing gel was screened,and the salicylic acid aqueous gel was prepared.The properties,pH value and viscosity were determined,and the stability,antibacterial activity and irritation were evaluated.The experimental results showed that the best gel matrix was cellulose,which had the best stability,could increase the solubility of salicylic acid in gel preparations,solved the problem of easy precipitation of salicylic acid crystals,enhanced the antibacterial activity,and reduced irritation,providing a reference for the application of salicylic acid in cosmetics.展开更多
Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of...Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.展开更多
The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components.However,the presence of the critical classical complemen...The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components.However,the presence of the critical classical complement component C1q,which links the innate and adaptive immune systems of mammalians,has not been explored in a primitive actinopterygian fish.In this study,we report that C1q is present in the skin mucus of the Siberian sturgeon(Acipenser baerii).The skin mucus was able to inhibit the growth of Escherichia coli.The bacteriostatic activity of the skin mucus was reduced by heating and by pre-incubation with EDTA or mouse anti-human C1q antibody.We also detected C1q protein in skin mucus using the western blot procedure and isolated a cDNA that encodes the Siberian sturgeon C1qC,which had 44.7–51.4%identity with C1qCs in teleosts and tetrapods.A phylogenetic analysis revealed that Siberian sturgeon C1qC lies at the root of the actinopterygian branch and is separate from the tetrapod branch.The C1qC transcript was expressed in many tissues as well as in skin.Our data indicate that C1q is present in the skin mucus of the Siberian sturgeon to protect against water-borne bacteria,and the C1qC found in the sturgeon may represent the primitive form of teleost and tetrapod C1qCs.展开更多
基金funded by financial grants from the Education Department of Hunan Province(SCX1840 and CX20190515).
文摘Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced.At present,the control of P.nicotianae mainly depends on chemical methods,with considerable environmental and health issues.We investigated the effects of ethanol extracts from Scutellaria baicalensis Georgi(SBG)and Magnolia officinalis(MO).On mycelial growth,sporangium formation,and zoospore release of P.nicotianae.Both extracts inhibited the growth of P.nicotianae,with mycelial growth inhibition rates of 88.92%and 93.92%,respectively,at 40 mg/mL,and EC50 values of 5.39 and 5.74 mg/mL,respectively.The underlying mechanisms were the inhibition of sporangium formation,the reduction of zoospore number,and the destruction of the mycelium structure.At an SBG extract concentration of 16.17 mg/mL,the inhibition rates for sporangia and zoospores were 98.66%and 99.39%,respectively.At an MO extract concentration of 2.87 mg/mL,the production of sporangia and zoospores was completely inhibited.The hyphae treated with the two plant extracts showed different degrees of deformation and damage.Hyphae treated with SBG extract showed adhesion and local swelling,whereas treatment with MO extract resulted in broken hyphae.Mixture of the extracts resulted in a good synergistic effect.
基金supported by the Shaanxi Special Project of China(2018ZDXM-NY-084)。
文摘Several of the fungal species associated with Fuzhuan brick tea(FBT)are considered as potential probiotics,but few studies have investigated the probiotic properties of these fungi.Here,we isolated 18 fungal strains from two types of FBT and identified these strains based on internal transcribed spacer(ITS)fragment sequence similarity to reference strains(sequence similarity>98%).Of the 18 strains,10 tolerated simulated human digestive conditions for sufficient periods in vitro:pH 2-3,0.3%-0.5%(m/V)bile salts,and artificial gastrointestinal juices.We then measured the antimicrobial activity of the remaining 10 strains against 5 enteropathogenic bacteria and tested the bacteriostatic effects of the thalli and fermentation broth extracts.Of the 6 strains with strong bacteriostatic effects,we eliminated Eurotium cristatum S-9 due to its low hydrophobicity of(26.12±0.35)%.Finally,2 exhibited good adhesion abilities to human cells(>100%).Notably,2 strains can survive in vivo,because they can be isolated from C57BL/6 mice feces.Thus,2 strains,Aspergillus cristatus H-1 and A.cristatus H-5,are herein identified as promising candidate probiotic strains.It may be put forward a novel research focus on evaluating potential probiotic fungi from FBT.
文摘Taking salicylic acid as the active ingredient and 10%sodium hydroxide aqueous solution as the neutralizer,the best matrix for preparing gel was screened,and the salicylic acid aqueous gel was prepared.The properties,pH value and viscosity were determined,and the stability,antibacterial activity and irritation were evaluated.The experimental results showed that the best gel matrix was cellulose,which had the best stability,could increase the solubility of salicylic acid in gel preparations,solved the problem of easy precipitation of salicylic acid crystals,enhanced the antibacterial activity,and reduced irritation,providing a reference for the application of salicylic acid in cosmetics.
基金supported by the Natural Science Foundation of Tianjin(General Program,No.18JCYBJC19500)the Independent Innovation Fund of Tianjin University(No.2019XZS-0014)the Research Grants Council of Hong Kong(No.HKUST615408).
文摘Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.
基金supported by the Shanghai Universities First-class Disciplines Project of Fisheries and Innovation Program of Shanghai Municipal Education Commission(12YZ129).
文摘The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components.However,the presence of the critical classical complement component C1q,which links the innate and adaptive immune systems of mammalians,has not been explored in a primitive actinopterygian fish.In this study,we report that C1q is present in the skin mucus of the Siberian sturgeon(Acipenser baerii).The skin mucus was able to inhibit the growth of Escherichia coli.The bacteriostatic activity of the skin mucus was reduced by heating and by pre-incubation with EDTA or mouse anti-human C1q antibody.We also detected C1q protein in skin mucus using the western blot procedure and isolated a cDNA that encodes the Siberian sturgeon C1qC,which had 44.7–51.4%identity with C1qCs in teleosts and tetrapods.A phylogenetic analysis revealed that Siberian sturgeon C1qC lies at the root of the actinopterygian branch and is separate from the tetrapod branch.The C1qC transcript was expressed in many tissues as well as in skin.Our data indicate that C1q is present in the skin mucus of the Siberian sturgeon to protect against water-borne bacteria,and the C1qC found in the sturgeon may represent the primitive form of teleost and tetrapod C1qCs.
