Plasma-activated water(PAW),as an extended form of cold atmospheric-pressure plasma,greatly expands the application of plasma-based technology.The biological effects of PAW are closely related to the aqueous reactive ...Plasma-activated water(PAW),as an extended form of cold atmospheric-pressure plasma,greatly expands the application of plasma-based technology.The biological effects of PAW are closely related to the aqueous reactive species,which can be regulated by the activation process.In this study,surface plasma-activated air(SAA)and a He+O_(2)plasma jet(Jet)were parallelly combined(the SAA+Jet combination)or sequentially combined(the SAA→Jet combination and the Jet→SAA combination)to prepare plasma-activated saline(PAS).The PAS activated by the combinations exhibited stronger bactericidal effects than that activated by the SAA or the Jet alone.The concentrations of H_(2)O_(2)and NO_(2)^(-)were higher in the PAS activated by the Jet→SAA combination,while ONOO^(-)concentrations were close in the three kinds of PAS and^(1)O_(2)concentrations were higher in the PAS activated by the SAA+Jet combination.The analysis of scavengers also demonstrated that H_(2)O_(2),^(1)O_(2),and ONOO^(-)in the PAS activated by the SAA+Jet combination,and^(1)O_(2)in the PAS activated by the Jet→SAA combination played critical roles in bactericidal effects.Further,the effective placement time of the three PAS varied,and the PAS activated by the Jet→SAA combination could also inactivate 2.6-log_(10)of MRSA cells after placement for more than 60 min.The regulation of reactive species in plasma-activated water via different combinations of plasma devices could improve the directional application of plasma-activated water in the biomedical field.展开更多
in order to verify whether the bactericidal capacity of polymorphonuclear neutrophils (PMNs)could be abolished by the bypass-activated complement,intracellular bactericidal activity (ICBA),superoxide ions (O2-) and sp...in order to verify whether the bactericidal capacity of polymorphonuclear neutrophils (PMNs)could be abolished by the bypass-activated complement,intracellular bactericidal activity (ICBA),superoxide ions (O2-) and specific granules (SGs) 3 were determine展开更多
Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses, even against pebrine as well. Methods: Petri dishes...Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses, even against pebrine as well. Methods: Petri dishes and transmission electronic microscope were applied to observe silver nanoparticles against bacteria strains and nuclear polyhedral viruses (NPV) and cytoplasmic polyhedral viruses (CPV). For biological test, 108 CFU/mL NPV with strong pathogenicity, and the NPV samples treated with 1:100 ratio of “Sumerian Silver” for 8 hrs were sprayed on the mulberry leaves, respectively, for silkworm rearing. Conclusion: Silver nanoparticle solution showed a strong bactericidal effect against both G+ and G﹣bacterial pathogenic strains from Bombyx mori and mulberry. Under transmission electronic microscope (TEM), Bacillus sp. Samples showed light particles in the cells when treated with silver nanoparticles, in contrast, untreated samples showed homogeneity contents. Further, NPV particles showed no significant differences between treated and untreated samples, but CPV showed strong effects that almost all CPV were collapsed. For biological test, “Sumerian Silver” treated NPV showed no diseased silkworm but nearly all silkworms were dead with no treatment. It seems like that silver nanoparticles were proved to be more effective against CPV than that of NPV. The significant differences between two antivirus or virucidal mechanism should be greatly aroused the scientific interest.展开更多
Aims: The representativeness of the mandatory bacterial strains specified in European standards for in vitro assay of the bactericidal activity of antiseptics was evaluated by testing the activity of an antiseptic com...Aims: The representativeness of the mandatory bacterial strains specified in European standards for in vitro assay of the bactericidal activity of antiseptics was evaluated by testing the activity of an antiseptic combining chlorhexidine digluconate 0.2% and benzalkonium chloride 0.5% against 21 additional bacterial strains, and the positive interaction between these two biocidal agents was assessed. Methods and Results: The bactericidal activity of the antiseptic solution used pure or diluted was assessed according to the European standards EN 1040 and EN 13727. The contact time was 1 min at 20°C. Interfering substances used in the EN 13727 assay were bovine serum albumin and sheep erythrocytes, simulating “dirty” conditions, and hard water. A reduction of colony-forming units by ≥5 log10 was deemed to meet the requirements to conclude bactericidal activity. Under “basic” conditions, the bactericidal activity of the antiseptic was observed against all four mandatory strains specified in the standards as well as against nearly all the additional strains tested, including most of those with acquired antibiotic-resistance. The positive interaction between the two biocidal agents was also confirmed. Under “dirty” conditions, the bactericidal activity of the antiseptic solution was maintained against all the mandatory strains and was reduced against only four of the additional strains tested. Conclusions: With regard to the antiseptic tested and under the experimental conditions described, bactericidal activity evidenced against the mandatory strains appeared to be representative of that manifested against a wide range of the main pathogenic bacteria. Reduced bacterial activity against some of the additional strains tested (e.g. Enterobacteriaceae) was observed under “dirty” conditions. Significance and Impact of the Study: EN 13727 with some experimental adjustments represents an additional appropriate standard that needs to be considered for mucocutaneous antiseptic assessment. However, it may be worth including other specific bacterial strains to those specified in the standard, when evaluating antiseptics intended for use in certain clinical situations.展开更多
In this work, the isonicotinamide was coordinated to the Cobalt ion in oxidation state +2. The relevance of this work is the investigation of the in vitro bactericidal potential of the synthesized complex when tested ...In this work, the isonicotinamide was coordinated to the Cobalt ion in oxidation state +2. The relevance of this work is the investigation of the in vitro bactericidal potential of the synthesized complex when tested in Gram-positive and negative bacteria strains. This study is motivated by the need to obtain new materials that have antibiotic properties and that, in the future, may become an effective drug against resistant bacteria. A new coordination compound of Cobalt and isonicotinamide, [Co(H2O)(isn)3](BF4)2, was synthesized and described. The compound was characterized by thermoanalytical techniques TG-DTG and TG-DSC, where it was possible to propose the mechanism of thermal decomposition. Through the spectroscopy in the region of the medium infrared (FTIR), it is possible to infer the site of connection between isonicotinamide and metal. The bactericidal activity of [Co(H2O)(isn)3](BF4)2, CoCl2 and free Isonicotinamide were tested for the bacteria Streptococcus mutans (Gram+) and Escherichia coli (Gram−) and the synthesized compound showed to be sensitive for both bacteria.展开更多
Objective:To investigate in vitro and in vivo antibacterial potentials of Vitex negundo(V. negundo) leaf extracts against diverse enteric pathogens.Methods:Water and methanol extracts of V.negundo leaves were evaluate...Objective:To investigate in vitro and in vivo antibacterial potentials of Vitex negundo(V. negundo) leaf extracts against diverse enteric pathogens.Methods:Water and methanol extracts of V.negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion,viable bacterial cell count methods,determination of minimum inhibitory concentrations(MIC) and minimum bactericidal concentrations(MBC).Results:Methanol extract of V.negundo leaves showed potent antibacterial activity(inhibition zone:9.9-22.6 mm,MIC: 200-3 200μg/mL.MBC:200-6 400μg/mL) against all the pathogenic enteric bacteria(Vibrio cholerae.Vibrio parahemolyticus.Vibrio mimicus.Echerichia coli,Shigella spps.,and Aeromonas spps) tested.Methanol extract of V.negundo leaves showed potent bactericidal activity both in vitro laboratory conditions(MBC,200-400μg/mL) and in the intestinal environment(Dose,1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae,the major causative agent of cholera. Furthermore,assays using the mice cholera model showed that V.negundo methanol extract can protect mice from Vibrio cholerae infection and significandy decrease the mortality rate(P【0.0001). Conclusions:For the first time we showed thal medianol extract of V.negundo leaves exhibited strong vihriocidal activity both in vitro and in vivo conditions.Therefore,it will he useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.展开更多
Objective:To investigate in vitro and in vivo antibacterial potentials of Vitex negundo(V. negundo) leaf extracts against diverse enteric pathogens.Methods:Water and methanol extracts of V.negundo leaves were evaluate...Objective:To investigate in vitro and in vivo antibacterial potentials of Vitex negundo(V. negundo) leaf extracts against diverse enteric pathogens.Methods:Water and methanol extracts of V.negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion,viable bacterial cell count methods,determination of minimum inhibitory concentrations(MIC) and minimum bactericidal concentrations(MBC).Results:Methanol extract of V.negundo leaves showed potent antibacterial activity(inhibition zone:9.9- 22.6 mm,MIC: 200-3 200μg/mL,MBC:200-6 400μg/mL) against all the pathogenic enleric bacteria(Vibrio cholerae,Vibrio parahaemolyticus,Vibrio mimicus,Echerichia coli.Shigella spps.,and Aeromonas spps) tested.Methanol extract of V.negundo leaves showed potent bactericidal activity both in vitro laboratory conditions(MBC,200-400μg/mL) and in the intestinal environment(Dose,1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae,the major causative agent of cholera. Furthermore,assays using the mice cholera model showed that V.negundo methanol extract can protect mice from Vibrio cholerae infection and significantly decrease the mortality rate(P【0.0001).Conclusioas:For the first time we showed that methanol extract of V.negundo leaves exhibited strong vibriocidal activity both in vitro and in vivo conditions.Therefore,it will be useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.展开更多
Phototoxic treatments of pathogenic bacteria and fungi of trees induce oxidative damage that is preferable to toxic chemical treatment.Here,we used green methods to synthesize Chlorin e6 from chlorophyll a,which was e...Phototoxic treatments of pathogenic bacteria and fungi of trees induce oxidative damage that is preferable to toxic chemical treatment.Here,we used green methods to synthesize Chlorin e6 from chlorophyll a,which was extracted from crude silkworm excrement using concentrated(strong)alkali hydrolysis and acidification.The photosensitive bactericidal activities of the new chlorin were tested in vitro,and possible mechanisms of action are discussed.The results showed that Chlorin e6 can be lightactivated to have bactericidal activity against Escherichia coli,Bacillus subtilis and Fusarium oxysporum,but it had little bactericidal effect in the dark.This kind of chlorin compounds has great potential as a natural phototoxic antimicrobial compound to control harmful bacteria on the leaves in forestry systems.展开更多
Introduction In the preceding paper it was described that various 1-acyl-4-substituted thiosemicarbazides and their derivatives exhibited a broad spectrum of antibacterial activities. Kothari pointed out that some het...Introduction In the preceding paper it was described that various 1-acyl-4-substituted thiosemicarbazides and their derivatives exhibited a broad spectrum of antibacterial activities. Kothari pointed out that some heterocycles linked with tetrazole and 1,2,4-triazole can be used as antiinflammatory agent. We have also demonstrated that both 3-(5-a- naphthyl)-2H-tetrazol-2-ylmethyl)-4-aryl-1,2,4-triazole-5-thiones and 3-(3-pyridyl)-展开更多
One of the major challenges faced by the biomedical industry is the development of robust synthetic surfaces that can resist bacterial colonization. Much inspiration has been drawn recently from naturally occurring me...One of the major challenges faced by the biomedical industry is the development of robust synthetic surfaces that can resist bacterial colonization. Much inspiration has been drawn recently from naturally occurring mechano-bactericidal surfaces such as the wings of cicada(Psaltoda claripennis) and dragonfly(Diplacodes bipunctata) species in fabricating their synthetic analogs. However,the bactericidal activity of nanostructured surfaces is observed in a particular range of parameters reflecting the geometry of nanostructures and surface wettability. Here,several of the nanometer-scale characteristics of black silicon(bSi) surfaces including the density and height of the nanopillars that have the potential to influence the bactericidal efficiency of these nanostructured surfaces have been investigated. The results provide important evidence that minor variations in the nanoarchitecture of substrata can substantially alter their performance as bactericidal surfaces.展开更多
Objective:To design a bi-functional antimicrobial peptide with bactericidal and endotoxin neutralization activity,and explore its bactericidal properties.Methods:The LBP(86-99)peptides and HLF(1-11)peptides were conne...Objective:To design a bi-functional antimicrobial peptide with bactericidal and endotoxin neutralization activity,and explore its bactericidal properties.Methods:The LBP(86-99)peptides and HLF(1-11)peptides were connected by a GGGS flexible 4-peptide linker to obtain the bi-functional antimicrobial peptide,which was named LLH.The secondary structure characteristics of LLH were analyzed by Emboss software.The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of LLH against Escherichia coli ATCC25922 and DH5αwere determined by the microtiter broth dilution method.The bactericidal kinetics of LLH was characterized and its effect on endotoxin neutralization was determined.The hemolysis of LLH was evaluated.Results:LLH carried a positive charge of+9,exhibitedβ-folding andβ-corner structure,and had strong hydrophobicity.The MIC of LLH against Escherichia coli ATCC25922 and DH5αwas 4μM,and the MBC of LLH against Escherichia coli ATCC25922 and DH5αwas 8 and 4μM,respectively.LLH showed rapid bactericidal effects and significantly neutralized the endotoxin released in the sterilization process as well as reducing release of endotoxin.LLH showed no significant hemolysis at concentrations up to 400μg/mL.Conclusion:LLH produces dual effects of rapid sterilization and endotoxin neutralization,and does not induce significant hemolysis.展开更多
objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. co...objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. coli 026:B6 LPS was injected at a dosage of 12. 5 mg/kg through the artery to reproduce endo toxic shock. BPIP at a dosage of 5 mg/kg (BPIP-treated group) or equal volume of normal saline (control group) were injected immediately after the injection of LPS. Results: ①Survival time of the shocked animals was prolonged and the 24 h survival rate was also significantly increased in BPIP-treated group as compared with the control group. ②The mean arterial pressure, left intraventricular systolic pressure, isovolemic ven tricular pressure and ±dp/dtmax. were significantly higher in BPIP-treated group than in control group. ③ Plasma levels of glutamic-pyruvic transaminase and urea nitrogen were markedly higher but those of endotox in and TNFα were lower in BPIP-treated group than in control group. Conclusion: BPIP can exert significant protective effects on cardiac, hepatic and renal functions in rats after endotoxic shock, indicating that BPIP might be a good choice in treatment of sepsis/septic shock.展开更多
This paper summarizes preliminary rat studies aimed at identifying the effectiveness of using electrically stimulated silver as a bactericidal agent for indwelling residual hardware devices (RHD). A variety of bacteri...This paper summarizes preliminary rat studies aimed at identifying the effectiveness of using electrically stimulated silver as a bactericidal agent for indwelling residual hardware devices (RHD). A variety of bactericidal indwelling devices were designed, fabricated and surgically inserted into the medullary cavity of live rats. The rats were inoculated with Staphylococcus aureus to try and induce osteomyelitis. A total of 37 surgeries were performed by implanting the rats with both control and potentially bactericidal devices. As surgical procedures and devices were improved, it appeared that the implants produced antibiotic effects in the animals. All of the control animals and all of the animals where the device failed tested positive for Staphylococcus aureus growth. Of the rats with operational bactericidal devices (those that survived the surgery and incubation period), half tested negative for Staphylococcus aureus. The device designs are discussed in this paper along with the test procedures, operating practices and results. A statistical analysis of the results, which shows a very high confidence level in the effectiveness of electrically stimulated silver as a bactericidal agent/antibiotic, is also presented.展开更多
It is known that the factors identified as contributing to the bactericidal activity of honeys are the high sugar concentration, hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and low pH, and i...It is known that the factors identified as contributing to the bactericidal activity of honeys are the high sugar concentration, hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and low pH, and its bactericidal components depend on honey plant and natural environment. Manuka honey has been studied a lot about bactericidal effect. However, since Japanese honeys are mainly used as food, detailed analyzes of bactericidal components and its actions have not been reported. Therefore, we analyzed bactericidal components contained in nine Japanese honeys using Lucigenin-CL-HPLC. As our results, four species components of H<sub>2</sub>O<sub>2</sub>, glucose, fructose and methylglyoxal were detected from nine Japanese honeys. The H<sub>2</sub>O<sub>2</sub> concentrations were 4.1 × 10<sup>-5</sup> - 1.8 × 10<sup>-4</sup> mol/L, the glucose concentrations were 1.4 - 2.8 mol/L, the fructose concentrations were 1.9 - 2.4 mol/L, the methylglyoxal concentrations were 4.0 × 10<sup>-3</sup> - 1.6 × 10<sup>-2</sup> mol/L. In this study, we confirmed that methylglyoxal is also contained in Japanese honeys, although it is a bactericidal component which is reported to be characteristic of manuka honey. It is considered that the further study of Japanese honeys is useful for more safe use, quality control, and clinical application.展开更多
Previously, we demonstrated the virucidal efficacy of low concentration chlorine dioxide (ClO<sub>2</sub>) gas in room settings. The purpose of these studies was to evaluate novel ClO<sub>2</sub&g...Previously, we demonstrated the virucidal efficacy of low concentration chlorine dioxide (ClO<sub>2</sub>) gas in room settings. The purpose of these studies was to evaluate novel ClO<sub>2</sub> formats as potential biocidal interventions for real world congregate settings and air systems. Three types of studies were conducted to determine the efficacy of ClO<sub>2</sub> in reducing bacteria and mold in various workspaces: hard and soft surfaces (gymnasium & equipment), aerosol (in-room), and within a laboratory environment. The study demonstrated that ClO<sub>2</sub> was highly effective against both bacteria and mold with reduction ranging from 85.0% - > 99.4% for bacteria and >99.4% for yeast and mold. Treatments on hard and soft surfaces (gymnasiums and sports equipment), reduced bacteria by an average of 90% - 95%. The following treatments were applied overnight: 1) hard surface spraying with dilute ClO<sub>2</sub> solutions, 2) carpet and tumbling treatments with powdered ClO<sub>2</sub> releasing impregnates, and 3) HVAC treatment and overall room deodorization with low dose ClO<sub>2</sub> gas from controlled releasing sachets. The in-room study treating air with a ClO<sub>2</sub> filtration media also indicated significant air and surface room efficacy, with an average of 94% reduction in bacteria after 24-hour, and 99.4% reduction in mold after 24-hours. In a related air study, a biological combination of Raoultella terrigena and Staphylococcus aureus was injected as a bio-aerosol into a 4-inch diameter pipe with air flowing at approximately 1200 ft/min. Dry ClO<sub>2</sub> gas was introduced into the air flow to achieve an effective concentration of 5 or 10 ppmv. Air samples were collected at sampling ports downstream from the fan at 10, 22, 55 and 100 ft along the pipe and used to evaluate changes in airborne bacteria and mold. Testing was conducted in a laboratory setting at ambient conditions. The data showed ClO<sub>2</sub> gas reduced viable organisms at both gas concentrations, and indicated that reductions were higher for 10 ppmv concentration, and longer pipe runs. In a final study, laboratory application of gaseous chlorine dioxide was tested. Low gas release filter testing demonstrated significant surface reductions of airborne bacteria with an overall average 99.4% reduction in the 24-hour testing period. Higher gas treatments of a class II biological cabinet reduced bacillus spores on steel coupons throughout cabinet by 6 log. ClO<sub>2</sub> was effective as a bactericidal and fungicidal treatment providing significant reduction in both surface and air. Novel product delivery forms may be useful for rapidly disinfecting air and solid surfaces in complex congregate settings.展开更多
Effects of bactericidal/permeability-increa protein(BPI, 1. 5 and 3. 5 rug/kg iv at the beginning of shock and resuscitation respectively) on the outcome of hemorrhagic shock was investigated in rats. Itwas found that...Effects of bactericidal/permeability-increa protein(BPI, 1. 5 and 3. 5 rug/kg iv at the beginning of shock and resuscitation respectively) on the outcome of hemorrhagic shock was investigated in rats. Itwas found that BPI administration could improve hepatic and renal functions after hemorrhagic shock, andenhance the survival rate of the rats with shock (BPI group: 81 % vs physiological saline group: 44 %, P <0.05). In BPI group, the plasma endotoxin level was not significantly changed (0. 20± 0. 04 at the end of resuscitation vs 0. 24± 0. 05 U/ml before shock). Tumor necrosis factor. and interleukin-6 levels in BPI group, although higher after shock and resuscitation, were significantly lower than those in physiologia saline group.It is suggested that BPI exerts a protective effects on rats with hernorrhagic shock, which might be due to itsaction against hemorrhage-induced endotoxin translocation and its inhibition of cytokine responses in shock,展开更多
This research was directed to understand the bactericidal effect of epidermal mucus of two Asian cat fish species viz.Clarias batrachus and Heteropneustes fossilis.Epidermal mucus extracts(raw and diluted)of both cat ...This research was directed to understand the bactericidal effect of epidermal mucus of two Asian cat fish species viz.Clarias batrachus and Heteropneustes fossilis.Epidermal mucus extracts(raw and diluted)of both cat fish species were tested against several Gram negative(Pseudomonas aeruginosa,Escherichia coli,Klebsiella pneumonia,A.hydrophila)and Gram positive bacterial strains(Bacillius cereus,Staphylococcus aureus,S.epidermidis)and antibacterial results were also compared with two standard antibiotics viz.amikacin and chloramphenicol used as positive control.An A.hydrophila challenge experiment was also performed on all selected test fish species to examine the change in the amount of mucus production and its bactericidal impact..Both epidermal mucus extracts(raw and diluted)of all selected normal and bacterial challenged test objects showed potent bactericidal effect against all pathogenic bacterial strains taken under study.However,former was more effective than later.Also raw epidermal mucus extracts of both normal and bacterial challenged cat fish species exhibited significantly higher ZOI values against all selected microbial strains than diluted mucus extracts and antibiotic chloramphenicol.Hence,these outcomes have clearly revealed that this cost effective natural product acquired from fishes is the key component of their defensive system.Therefore,it could be utilized as a novel‘antimicrobial’in human as well as veterinary sector for combating against several bacterial diseases.展开更多
In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in aquaculture.In the present study a strain of Lactobacillus pentosus,name...In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in aquaculture.In the present study a strain of Lactobacillus pentosus,named as L.pentosus SF-1,was isolated from waters in aquaculture.The species identification of this strain was conducted by 16S rRNA sequence,and the physiological and biochemical characteristics of this strain were assessed.Furthermore,the virulence,antibiotic sensitivity,cell surface characteristics and acid/base-resistance of L.pentosus SF-1 were determined to evaluate the probiotic potentials of this strain.Specifically,L.pentosus SF-1 is sensitive to most common antibiotics,and no hemolysin was generated from it,indicating the safety of this strain to hosts.In addition,L.pentosus SF-1 was able to tolerate the artificial gastric juice at pH 3 for 4 h and the artificial intestinal fluid at pH 6.8 or 8.0 for 6 h.Moreover,the analysis of self-aggregation and the adhesion of L.pentosus SF-1 to organic solvents suggested a high potential of L.pentosus SF-1 to inhabit the hosts,which was confirmed by testing the colonization of L.pentosus SF-1 in germ-free zebrafish.Interestingly,L.pentosus SF-1 displayed a high bactericidal activity against several bacterial pathogens.Consistently,the incubation of L.pentosus SF-1 significantly promoted the expression of antimicrobial components in zebrafish,contributing to the protection of the fish from E.tarda infection in vivo.Taken together,the probiotic strain L.pentosus SF-1 could be applied as anti-infection reagent in aquaculture.展开更多
Bacterial cell wall component-induced tolerance represents an important protective mechanism during microbial infection.Tolerance induced by the TLR2 agonist bacterial lipoprotein(BLP)has been shown to attenuate the i...Bacterial cell wall component-induced tolerance represents an important protective mechanism during microbial infection.Tolerance induced by the TLR2 agonist bacterial lipoprotein(BLP)has been shown to attenuate the inflammatory response,and simultaneously to augment antimicrobial function,thereby conferring its protection against microbial sepsis.However,the underlying mechanism by which BLP tolerance augments bactericidal activity has not been fully elucidated.Here,we reported that the induction of BLP tolerance in murine macrophages upregulated the expression of Rab20,a membrane trafficking regulator,at both the mRNA and protein levels upon bacterial infection.The knockdown of Rab20 with Rab20 specific siRNA(siRab20)did not affect the phagocytosis of Escherichia coli(E.coli),but substantially impaired the intracellular killing of the ingested E.coli in BLP-tolerized macrophages.Furthermore,Rab20 was associated with GFP-E.coli containing phagosomes,and BLP tolerization resulted in the enhanced maturation of GFP-E.coli-containing phagosomes associated with Rab20 and strong lysosomal acidification.The knockdown of Rab20 substantially diminished lysosome acidification and disturbed the fusion of GFP-E.coli containing phagosomes with lysosomes in BLP-tolerized macrophages.These results demonstrate that Rab20 plays a critical role in BLP tolerization-induced augmentation of bactericidal activity via promoting phagosome maturation and the fusion of bacteria containing phagosomes with lysosomes.展开更多
基金supported by National Natural Science Foundation of China(No.51977174)。
文摘Plasma-activated water(PAW),as an extended form of cold atmospheric-pressure plasma,greatly expands the application of plasma-based technology.The biological effects of PAW are closely related to the aqueous reactive species,which can be regulated by the activation process.In this study,surface plasma-activated air(SAA)and a He+O_(2)plasma jet(Jet)were parallelly combined(the SAA+Jet combination)or sequentially combined(the SAA→Jet combination and the Jet→SAA combination)to prepare plasma-activated saline(PAS).The PAS activated by the combinations exhibited stronger bactericidal effects than that activated by the SAA or the Jet alone.The concentrations of H_(2)O_(2)and NO_(2)^(-)were higher in the PAS activated by the Jet→SAA combination,while ONOO^(-)concentrations were close in the three kinds of PAS and^(1)O_(2)concentrations were higher in the PAS activated by the SAA+Jet combination.The analysis of scavengers also demonstrated that H_(2)O_(2),^(1)O_(2),and ONOO^(-)in the PAS activated by the SAA+Jet combination,and^(1)O_(2)in the PAS activated by the Jet→SAA combination played critical roles in bactericidal effects.Further,the effective placement time of the three PAS varied,and the PAS activated by the Jet→SAA combination could also inactivate 2.6-log_(10)of MRSA cells after placement for more than 60 min.The regulation of reactive species in plasma-activated water via different combinations of plasma devices could improve the directional application of plasma-activated water in the biomedical field.
文摘in order to verify whether the bactericidal capacity of polymorphonuclear neutrophils (PMNs)could be abolished by the bypass-activated complement,intracellular bactericidal activity (ICBA),superoxide ions (O2-) and specific granules (SGs) 3 were determine
文摘Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses, even against pebrine as well. Methods: Petri dishes and transmission electronic microscope were applied to observe silver nanoparticles against bacteria strains and nuclear polyhedral viruses (NPV) and cytoplasmic polyhedral viruses (CPV). For biological test, 108 CFU/mL NPV with strong pathogenicity, and the NPV samples treated with 1:100 ratio of “Sumerian Silver” for 8 hrs were sprayed on the mulberry leaves, respectively, for silkworm rearing. Conclusion: Silver nanoparticle solution showed a strong bactericidal effect against both G+ and G﹣bacterial pathogenic strains from Bombyx mori and mulberry. Under transmission electronic microscope (TEM), Bacillus sp. Samples showed light particles in the cells when treated with silver nanoparticles, in contrast, untreated samples showed homogeneity contents. Further, NPV particles showed no significant differences between treated and untreated samples, but CPV showed strong effects that almost all CPV were collapsed. For biological test, “Sumerian Silver” treated NPV showed no diseased silkworm but nearly all silkworms were dead with no treatment. It seems like that silver nanoparticles were proved to be more effective against CPV than that of NPV. The significant differences between two antivirus or virucidal mechanism should be greatly aroused the scientific interest.
文摘Aims: The representativeness of the mandatory bacterial strains specified in European standards for in vitro assay of the bactericidal activity of antiseptics was evaluated by testing the activity of an antiseptic combining chlorhexidine digluconate 0.2% and benzalkonium chloride 0.5% against 21 additional bacterial strains, and the positive interaction between these two biocidal agents was assessed. Methods and Results: The bactericidal activity of the antiseptic solution used pure or diluted was assessed according to the European standards EN 1040 and EN 13727. The contact time was 1 min at 20°C. Interfering substances used in the EN 13727 assay were bovine serum albumin and sheep erythrocytes, simulating “dirty” conditions, and hard water. A reduction of colony-forming units by ≥5 log10 was deemed to meet the requirements to conclude bactericidal activity. Under “basic” conditions, the bactericidal activity of the antiseptic was observed against all four mandatory strains specified in the standards as well as against nearly all the additional strains tested, including most of those with acquired antibiotic-resistance. The positive interaction between the two biocidal agents was also confirmed. Under “dirty” conditions, the bactericidal activity of the antiseptic solution was maintained against all the mandatory strains and was reduced against only four of the additional strains tested. Conclusions: With regard to the antiseptic tested and under the experimental conditions described, bactericidal activity evidenced against the mandatory strains appeared to be representative of that manifested against a wide range of the main pathogenic bacteria. Reduced bacterial activity against some of the additional strains tested (e.g. Enterobacteriaceae) was observed under “dirty” conditions. Significance and Impact of the Study: EN 13727 with some experimental adjustments represents an additional appropriate standard that needs to be considered for mucocutaneous antiseptic assessment. However, it may be worth including other specific bacterial strains to those specified in the standard, when evaluating antiseptics intended for use in certain clinical situations.
文摘In this work, the isonicotinamide was coordinated to the Cobalt ion in oxidation state +2. The relevance of this work is the investigation of the in vitro bactericidal potential of the synthesized complex when tested in Gram-positive and negative bacteria strains. This study is motivated by the need to obtain new materials that have antibiotic properties and that, in the future, may become an effective drug against resistant bacteria. A new coordination compound of Cobalt and isonicotinamide, [Co(H2O)(isn)3](BF4)2, was synthesized and described. The compound was characterized by thermoanalytical techniques TG-DTG and TG-DSC, where it was possible to propose the mechanism of thermal decomposition. Through the spectroscopy in the region of the medium infrared (FTIR), it is possible to infer the site of connection between isonicotinamide and metal. The bactericidal activity of [Co(H2O)(isn)3](BF4)2, CoCl2 and free Isonicotinamide were tested for the bacteria Streptococcus mutans (Gram+) and Escherichia coli (Gram−) and the synthesized compound showed to be sensitive for both bacteria.
文摘Objective:To investigate in vitro and in vivo antibacterial potentials of Vitex negundo(V. negundo) leaf extracts against diverse enteric pathogens.Methods:Water and methanol extracts of V.negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion,viable bacterial cell count methods,determination of minimum inhibitory concentrations(MIC) and minimum bactericidal concentrations(MBC).Results:Methanol extract of V.negundo leaves showed potent antibacterial activity(inhibition zone:9.9-22.6 mm,MIC: 200-3 200μg/mL.MBC:200-6 400μg/mL) against all the pathogenic enteric bacteria(Vibrio cholerae.Vibrio parahemolyticus.Vibrio mimicus.Echerichia coli,Shigella spps.,and Aeromonas spps) tested.Methanol extract of V.negundo leaves showed potent bactericidal activity both in vitro laboratory conditions(MBC,200-400μg/mL) and in the intestinal environment(Dose,1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae,the major causative agent of cholera. Furthermore,assays using the mice cholera model showed that V.negundo methanol extract can protect mice from Vibrio cholerae infection and significandy decrease the mortality rate(P【0.0001). Conclusions:For the first time we showed thal medianol extract of V.negundo leaves exhibited strong vihriocidal activity both in vitro and in vivo conditions.Therefore,it will he useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.
文摘Objective:To investigate in vitro and in vivo antibacterial potentials of Vitex negundo(V. negundo) leaf extracts against diverse enteric pathogens.Methods:Water and methanol extracts of V.negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion,viable bacterial cell count methods,determination of minimum inhibitory concentrations(MIC) and minimum bactericidal concentrations(MBC).Results:Methanol extract of V.negundo leaves showed potent antibacterial activity(inhibition zone:9.9- 22.6 mm,MIC: 200-3 200μg/mL,MBC:200-6 400μg/mL) against all the pathogenic enleric bacteria(Vibrio cholerae,Vibrio parahaemolyticus,Vibrio mimicus,Echerichia coli.Shigella spps.,and Aeromonas spps) tested.Methanol extract of V.negundo leaves showed potent bactericidal activity both in vitro laboratory conditions(MBC,200-400μg/mL) and in the intestinal environment(Dose,1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae,the major causative agent of cholera. Furthermore,assays using the mice cholera model showed that V.negundo methanol extract can protect mice from Vibrio cholerae infection and significantly decrease the mortality rate(P【0.0001).Conclusioas:For the first time we showed that methanol extract of V.negundo leaves exhibited strong vibriocidal activity both in vitro and in vivo conditions.Therefore,it will be useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.
基金supported by Fundamental Research Funds for the Central Universities(No.DL12BA06)Harbin Science and Technology Innovation Talent Research Special Funds(2015RAQXJ002)
文摘Phototoxic treatments of pathogenic bacteria and fungi of trees induce oxidative damage that is preferable to toxic chemical treatment.Here,we used green methods to synthesize Chlorin e6 from chlorophyll a,which was extracted from crude silkworm excrement using concentrated(strong)alkali hydrolysis and acidification.The photosensitive bactericidal activities of the new chlorin were tested in vitro,and possible mechanisms of action are discussed.The results showed that Chlorin e6 can be lightactivated to have bactericidal activity against Escherichia coli,Bacillus subtilis and Fusarium oxysporum,but it had little bactericidal effect in the dark.This kind of chlorin compounds has great potential as a natural phototoxic antimicrobial compound to control harmful bacteria on the leaves in forestry systems.
文摘Introduction In the preceding paper it was described that various 1-acyl-4-substituted thiosemicarbazides and their derivatives exhibited a broad spectrum of antibacterial activities. Kothari pointed out that some heterocycles linked with tetrazole and 1,2,4-triazole can be used as antiinflammatory agent. We have also demonstrated that both 3-(5-a- naphthyl)-2H-tetrazol-2-ylmethyl)-4-aryl-1,2,4-triazole-5-thiones and 3-(3-pyridyl)-
基金funding from Marie Curie Actions under EU FP7 Initial Training Network SNAL 608184
文摘One of the major challenges faced by the biomedical industry is the development of robust synthetic surfaces that can resist bacterial colonization. Much inspiration has been drawn recently from naturally occurring mechano-bactericidal surfaces such as the wings of cicada(Psaltoda claripennis) and dragonfly(Diplacodes bipunctata) species in fabricating their synthetic analogs. However,the bactericidal activity of nanostructured surfaces is observed in a particular range of parameters reflecting the geometry of nanostructures and surface wettability. Here,several of the nanometer-scale characteristics of black silicon(bSi) surfaces including the density and height of the nanopillars that have the potential to influence the bactericidal efficiency of these nanostructured surfaces have been investigated. The results provide important evidence that minor variations in the nanoarchitecture of substrata can substantially alter their performance as bactericidal surfaces.
基金Hainan University Scientific Research Funding Project(No.Hnky2019ZD-32)。
文摘Objective:To design a bi-functional antimicrobial peptide with bactericidal and endotoxin neutralization activity,and explore its bactericidal properties.Methods:The LBP(86-99)peptides and HLF(1-11)peptides were connected by a GGGS flexible 4-peptide linker to obtain the bi-functional antimicrobial peptide,which was named LLH.The secondary structure characteristics of LLH were analyzed by Emboss software.The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of LLH against Escherichia coli ATCC25922 and DH5αwere determined by the microtiter broth dilution method.The bactericidal kinetics of LLH was characterized and its effect on endotoxin neutralization was determined.The hemolysis of LLH was evaluated.Results:LLH carried a positive charge of+9,exhibitedβ-folding andβ-corner structure,and had strong hydrophobicity.The MIC of LLH against Escherichia coli ATCC25922 and DH5αwas 4μM,and the MBC of LLH against Escherichia coli ATCC25922 and DH5αwas 8 and 4μM,respectively.LLH showed rapid bactericidal effects and significantly neutralized the endotoxin released in the sterilization process as well as reducing release of endotoxin.LLH showed no significant hemolysis at concentrations up to 400μg/mL.Conclusion:LLH produces dual effects of rapid sterilization and endotoxin neutralization,and does not induce significant hemolysis.
文摘objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. coli 026:B6 LPS was injected at a dosage of 12. 5 mg/kg through the artery to reproduce endo toxic shock. BPIP at a dosage of 5 mg/kg (BPIP-treated group) or equal volume of normal saline (control group) were injected immediately after the injection of LPS. Results: ①Survival time of the shocked animals was prolonged and the 24 h survival rate was also significantly increased in BPIP-treated group as compared with the control group. ②The mean arterial pressure, left intraventricular systolic pressure, isovolemic ven tricular pressure and ±dp/dtmax. were significantly higher in BPIP-treated group than in control group. ③ Plasma levels of glutamic-pyruvic transaminase and urea nitrogen were markedly higher but those of endotox in and TNFα were lower in BPIP-treated group than in control group. Conclusion: BPIP can exert significant protective effects on cardiac, hepatic and renal functions in rats after endotoxic shock, indicating that BPIP might be a good choice in treatment of sepsis/septic shock.
文摘This paper summarizes preliminary rat studies aimed at identifying the effectiveness of using electrically stimulated silver as a bactericidal agent for indwelling residual hardware devices (RHD). A variety of bactericidal indwelling devices were designed, fabricated and surgically inserted into the medullary cavity of live rats. The rats were inoculated with Staphylococcus aureus to try and induce osteomyelitis. A total of 37 surgeries were performed by implanting the rats with both control and potentially bactericidal devices. As surgical procedures and devices were improved, it appeared that the implants produced antibiotic effects in the animals. All of the control animals and all of the animals where the device failed tested positive for Staphylococcus aureus growth. Of the rats with operational bactericidal devices (those that survived the surgery and incubation period), half tested negative for Staphylococcus aureus. The device designs are discussed in this paper along with the test procedures, operating practices and results. A statistical analysis of the results, which shows a very high confidence level in the effectiveness of electrically stimulated silver as a bactericidal agent/antibiotic, is also presented.
文摘It is known that the factors identified as contributing to the bactericidal activity of honeys are the high sugar concentration, hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and low pH, and its bactericidal components depend on honey plant and natural environment. Manuka honey has been studied a lot about bactericidal effect. However, since Japanese honeys are mainly used as food, detailed analyzes of bactericidal components and its actions have not been reported. Therefore, we analyzed bactericidal components contained in nine Japanese honeys using Lucigenin-CL-HPLC. As our results, four species components of H<sub>2</sub>O<sub>2</sub>, glucose, fructose and methylglyoxal were detected from nine Japanese honeys. The H<sub>2</sub>O<sub>2</sub> concentrations were 4.1 × 10<sup>-5</sup> - 1.8 × 10<sup>-4</sup> mol/L, the glucose concentrations were 1.4 - 2.8 mol/L, the fructose concentrations were 1.9 - 2.4 mol/L, the methylglyoxal concentrations were 4.0 × 10<sup>-3</sup> - 1.6 × 10<sup>-2</sup> mol/L. In this study, we confirmed that methylglyoxal is also contained in Japanese honeys, although it is a bactericidal component which is reported to be characteristic of manuka honey. It is considered that the further study of Japanese honeys is useful for more safe use, quality control, and clinical application.
文摘Previously, we demonstrated the virucidal efficacy of low concentration chlorine dioxide (ClO<sub>2</sub>) gas in room settings. The purpose of these studies was to evaluate novel ClO<sub>2</sub> formats as potential biocidal interventions for real world congregate settings and air systems. Three types of studies were conducted to determine the efficacy of ClO<sub>2</sub> in reducing bacteria and mold in various workspaces: hard and soft surfaces (gymnasium & equipment), aerosol (in-room), and within a laboratory environment. The study demonstrated that ClO<sub>2</sub> was highly effective against both bacteria and mold with reduction ranging from 85.0% - > 99.4% for bacteria and >99.4% for yeast and mold. Treatments on hard and soft surfaces (gymnasiums and sports equipment), reduced bacteria by an average of 90% - 95%. The following treatments were applied overnight: 1) hard surface spraying with dilute ClO<sub>2</sub> solutions, 2) carpet and tumbling treatments with powdered ClO<sub>2</sub> releasing impregnates, and 3) HVAC treatment and overall room deodorization with low dose ClO<sub>2</sub> gas from controlled releasing sachets. The in-room study treating air with a ClO<sub>2</sub> filtration media also indicated significant air and surface room efficacy, with an average of 94% reduction in bacteria after 24-hour, and 99.4% reduction in mold after 24-hours. In a related air study, a biological combination of Raoultella terrigena and Staphylococcus aureus was injected as a bio-aerosol into a 4-inch diameter pipe with air flowing at approximately 1200 ft/min. Dry ClO<sub>2</sub> gas was introduced into the air flow to achieve an effective concentration of 5 or 10 ppmv. Air samples were collected at sampling ports downstream from the fan at 10, 22, 55 and 100 ft along the pipe and used to evaluate changes in airborne bacteria and mold. Testing was conducted in a laboratory setting at ambient conditions. The data showed ClO<sub>2</sub> gas reduced viable organisms at both gas concentrations, and indicated that reductions were higher for 10 ppmv concentration, and longer pipe runs. In a final study, laboratory application of gaseous chlorine dioxide was tested. Low gas release filter testing demonstrated significant surface reductions of airborne bacteria with an overall average 99.4% reduction in the 24-hour testing period. Higher gas treatments of a class II biological cabinet reduced bacillus spores on steel coupons throughout cabinet by 6 log. ClO<sub>2</sub> was effective as a bactericidal and fungicidal treatment providing significant reduction in both surface and air. Novel product delivery forms may be useful for rapidly disinfecting air and solid surfaces in complex congregate settings.
文摘Effects of bactericidal/permeability-increa protein(BPI, 1. 5 and 3. 5 rug/kg iv at the beginning of shock and resuscitation respectively) on the outcome of hemorrhagic shock was investigated in rats. Itwas found that BPI administration could improve hepatic and renal functions after hemorrhagic shock, andenhance the survival rate of the rats with shock (BPI group: 81 % vs physiological saline group: 44 %, P <0.05). In BPI group, the plasma endotoxin level was not significantly changed (0. 20± 0. 04 at the end of resuscitation vs 0. 24± 0. 05 U/ml before shock). Tumor necrosis factor. and interleukin-6 levels in BPI group, although higher after shock and resuscitation, were significantly lower than those in physiologia saline group.It is suggested that BPI exerts a protective effects on rats with hernorrhagic shock, which might be due to itsaction against hemorrhage-induced endotoxin translocation and its inhibition of cytokine responses in shock,
文摘This research was directed to understand the bactericidal effect of epidermal mucus of two Asian cat fish species viz.Clarias batrachus and Heteropneustes fossilis.Epidermal mucus extracts(raw and diluted)of both cat fish species were tested against several Gram negative(Pseudomonas aeruginosa,Escherichia coli,Klebsiella pneumonia,A.hydrophila)and Gram positive bacterial strains(Bacillius cereus,Staphylococcus aureus,S.epidermidis)and antibacterial results were also compared with two standard antibiotics viz.amikacin and chloramphenicol used as positive control.An A.hydrophila challenge experiment was also performed on all selected test fish species to examine the change in the amount of mucus production and its bactericidal impact..Both epidermal mucus extracts(raw and diluted)of all selected normal and bacterial challenged test objects showed potent bactericidal effect against all pathogenic bacterial strains taken under study.However,former was more effective than later.Also raw epidermal mucus extracts of both normal and bacterial challenged cat fish species exhibited significantly higher ZOI values against all selected microbial strains than diluted mucus extracts and antibiotic chloramphenicol.Hence,these outcomes have clearly revealed that this cost effective natural product acquired from fishes is the key component of their defensive system.Therefore,it could be utilized as a novel‘antimicrobial’in human as well as veterinary sector for combating against several bacterial diseases.
基金supported by the National Natural Science Foundation of China(No.31972802)the Natural Science Foundation of Shandong Province(No.ZR2019MC041)the Taishan Scholar Program of Shandong Province(No.tsqn201812023).
文摘In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in aquaculture.In the present study a strain of Lactobacillus pentosus,named as L.pentosus SF-1,was isolated from waters in aquaculture.The species identification of this strain was conducted by 16S rRNA sequence,and the physiological and biochemical characteristics of this strain were assessed.Furthermore,the virulence,antibiotic sensitivity,cell surface characteristics and acid/base-resistance of L.pentosus SF-1 were determined to evaluate the probiotic potentials of this strain.Specifically,L.pentosus SF-1 is sensitive to most common antibiotics,and no hemolysin was generated from it,indicating the safety of this strain to hosts.In addition,L.pentosus SF-1 was able to tolerate the artificial gastric juice at pH 3 for 4 h and the artificial intestinal fluid at pH 6.8 or 8.0 for 6 h.Moreover,the analysis of self-aggregation and the adhesion of L.pentosus SF-1 to organic solvents suggested a high potential of L.pentosus SF-1 to inhabit the hosts,which was confirmed by testing the colonization of L.pentosus SF-1 in germ-free zebrafish.Interestingly,L.pentosus SF-1 displayed a high bactericidal activity against several bacterial pathogens.Consistently,the incubation of L.pentosus SF-1 significantly promoted the expression of antimicrobial components in zebrafish,contributing to the protection of the fish from E.tarda infection in vivo.Taken together,the probiotic strain L.pentosus SF-1 could be applied as anti-infection reagent in aquaculture.
基金This work was supported by the National Natural Science Foundation of China(81471901,81272149)the Guangdong Provincial Natural Science Foundation(2015A030311031,2018A0303130289)+1 种基金the Guangdong Provincial Key Laboratory Construction Project of China(2014B030301044)the South Wisdom Valley Innovative Research Team Program(CXTD-001).
文摘Bacterial cell wall component-induced tolerance represents an important protective mechanism during microbial infection.Tolerance induced by the TLR2 agonist bacterial lipoprotein(BLP)has been shown to attenuate the inflammatory response,and simultaneously to augment antimicrobial function,thereby conferring its protection against microbial sepsis.However,the underlying mechanism by which BLP tolerance augments bactericidal activity has not been fully elucidated.Here,we reported that the induction of BLP tolerance in murine macrophages upregulated the expression of Rab20,a membrane trafficking regulator,at both the mRNA and protein levels upon bacterial infection.The knockdown of Rab20 with Rab20 specific siRNA(siRab20)did not affect the phagocytosis of Escherichia coli(E.coli),but substantially impaired the intracellular killing of the ingested E.coli in BLP-tolerized macrophages.Furthermore,Rab20 was associated with GFP-E.coli containing phagosomes,and BLP tolerization resulted in the enhanced maturation of GFP-E.coli-containing phagosomes associated with Rab20 and strong lysosomal acidification.The knockdown of Rab20 substantially diminished lysosome acidification and disturbed the fusion of GFP-E.coli containing phagosomes with lysosomes in BLP-tolerized macrophages.These results demonstrate that Rab20 plays a critical role in BLP tolerization-induced augmentation of bactericidal activity via promoting phagosome maturation and the fusion of bacteria containing phagosomes with lysosomes.
