Comparison of the serum contents of inflammatory mediators and oxidative stress mediators between patients with gram-positive bacteria and gram-negative bacteria infection

Objective: To compare the serum contents of inflammatory mediators and oxidative stress mediators between patients with gram-positive bacteria and gram-negative bacteria infection. Methods: Patients who were diagnosed with bloodstream bacterial infection in Zigong Third People's Hospital between March 2015 and April 2017 were selected as the research subjects and divided into gram-positive group and gram-negative group according to the results of blood culture and strain identification, and serum levels of inflammatory mediators PCT, IL-1β, IL-6, sTREM-1, TNF-α, NGAL, SAA, HPT and hs-CRP as well as oxidative stress mediators MDA, AOPP, TAC, CAT and SOD were determined. Results: Serum PCT, IL-1β, IL-6, sTREM-1, TNF-α, NGAL, SAA, HPT, hs-CRP, MDA and AOPP levels of gram-negative group were greatly higher than those of gram-positive group while TAC, CAT and SOD levels were greatly lower than those of gram-positive group. Conclusion: The changes of inflammatory mediators and oxidative stress mediators in the serum of patients with gram-negative bacteria infection are more significant than those of patients with gram-positive bacteria infection.

Antibacterial Effect of Waste Liquor of Essence Oil Extraction from Sabina vulgaris Ant in Foods

The antibacterial effects of waste liquor of essence oil extraction from Sabina vulgaris Ant on Escherichia coil, Staphylococcus aureus, Salmonella, Bacillus subtilis, Bacillus magaterium and Bacillus cereus in foods were evaluated by paper disk method. The results showed that the waste liquor of essence oil extraction from S. vulgaris had inhibitory effects on E. coil, S. aureus and Salmonella with bet- ter inhibitory effects on E. coil and Salmonella; the bacteriostatic effect of water steam distillation waste liquor was better than that of water extraction waste liquor. The more times the waste liquor was distilled, the higher the active ingredients content was, and the better the bacteriostatic effect was.

Drug Sensitive Test on Main Pathogenic Bacteria of Cow Recessiveness Mastitis Using Traditional Chinese Medicine Preparation “Zengrujianniusan”

According to the theory of Chinese veterinary medicine and characteristics of Chinese herbal medicine, four different preparations of compound Chinese medicine ＂Zengrujianniusan＂ were composed, and the prepared water decoction was used to carry on the bacteriostatic test on main pathogens of cow recessiveness mastitis. The results showed that the four different prescriptions of water decoction all had antibacterial effects. The prescription 3 was sensitive to Staphylococcus aureus and Streptococcus agalactiae, while the other three prescriptions showed high sensitivity, and the prescription 3 had the strongest bacteriostatic effects.

Antibacterial activity of leaves extracts of Trifolium alexandrinum Linn,against pathogenic bacteria causing tropical diseases

Objective:To investigate antibacterial potential of Trifolium alexandrinum(T.alexandrinum) Linn,against seven gram positive and eleven gram negative hospital isolated human pathogenic bacterial strains responsible for many tropical diseases.Methods:Non-polar and polar extracts of the leaves of T.alexandrinum i.e.,hexane,dichloromethane(DCM),ethyl acetate(EtOAc), methanol(MeOH) and aqueous(AQ) extracts at five different concentrations(1,2,5,10 and 15 mg/ mL) were prepared to evaluate their antibacterial value.NCCL standards were strictly followed to perform antimicrobial disc susceptibility test using disc diffusion method.Results:Polar extracts demonstrated significant antibacterial activity against tested pathogens.EtOAc and MeOH extracts showed maximum antibacterial activity with higher inhibition zone and were found effective against seventeen of the tested pathogens.While AQ plant extract inhibited the growth of sixteen of the test strains.EtOAc and MeOH plant extracts inhibited the growth of all seven gram positive and ten of the gram negative bacterial strains.Conclusions:The present study strongly confirms the effectiveness of crude leaves extracts against tested human pathogenic bacterial strains causing several tropical diseases.Since Egyptian clover is used as a fodder plant,it could be helpful in controlling various infectious diseases associated with cattle as well.

Antibacterial activity of bioceramic coatings on Mg and its alloys created by plasma electrolytic oxidation(PEO): A review

Mg and its alloys are suitable choices for implant materials due to their biodegradability and biocompatibility features. However, the high electrochemical activity of this family of biomaterials results in their fast degradation and severe corrosion in the physiological environment,producing hydrogen(H;) gas, and therefore increasing the p H of the environment. To meet the clinical requirements, the degradation rate of Mg biomaterials needs to be reduced. Nevertheless, higher corrosion resistance of Mg results in a low alkaline p H, weakening the antibacterial activity. Therefore, while the rapid degradation problem of Mg-based biomaterials needs to be addressed, good antibacterial properties are also necessary. By using the plasma electrolytic oxidation(PEO) surface modification technique, the antibacterial activity of Mg and its alloys can be enhanced while maintaining their corrosion protection properties at a high level. Throughout the PEO process, introducing antibacterial agents into solutions results in a major increase in antibacterial activity of the coatings. Moreover, post-or pre-processing on PEO coatings can provide better protection against bacteria. In this review, the antibacterial activity of PEO coatings applied on Mg and also its alloys will be discussed in more detail.

传统发酵乳品中产广谱细菌素乳酸菌选育

为选育产广谱细菌素乳酸菌,采用琼脂扩散法对甘肃牧区传统发酵乳品中分离纯化的96株乳酸菌进行了筛选,并确定产细菌素菌株,具有最佳抑菌效果的菌株经重离子束12C6+辐照诱变,再采用培养皿分区法进行6种指示菌广谱抑菌性能比较。结果表明,琼脂扩散法筛选出抑菌效果最佳的产细菌素菌株Lp1,经辐照诱变得到98株突变菌,选育出对大肠埃希氏菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)、单核细胞增生李斯特氏菌(Listeria monocytogenes)、沙门氏菌(Salmonella)、志贺氏菌(Shigella)和克罗诺杆菌(Cronobacter)抑菌性能均明显优于出发菌株Lp1的5株突变株L088、L087、L063、L049、L010进行广谱抑菌试验,其中菌株L088和L063为广谱抑菌性能较好菌株,突变株L088对上述6种指示菌的抑菌扇环半径比出发菌株Lp1抑菌扇环半径分别提高47.81%、33.28%、22.97%、45.25%、21.39%、40.21%,突变株L063对上述6种指示菌的抑菌扇环半径比出发菌株Lp1抑菌扇环半径分别提高54.27%、29.18%、25.37%、58.03%、17.85%、42.13%。采用培养皿分区法可同时在1个培养皿中完成检测6种指示菌的抑菌试验,可高效筛选产广谱细菌素乳酸菌。

泡菜中乳酸菌的抑菌性能及生长特性探究

从四川传统泡菜母水中分离出具有抑菌功能的乳酸菌分别为XZ5和XZ11,并对其进行鉴定和生长特性研究。利用形态、生理生化和16S rRNA测序等方法对菌种进行鉴定,并研究这两株菌的生长特性。结果表明,菌株XZ5对沙门氏菌和大肠杆菌的抑菌直径分别为11.3±0.3 mm和10.9±0.5 mm,而菌株XZ11的抑菌圈直径为9.3±0.7 mm和6.8±0.3 mm。菌株XZ5和XZ11通过革兰氏染色鉴定为阳性的杆菌,其测序结果分别为德氏乳杆菌(Lactobacillus delbrueckii)和短乳杆菌(Lactobacillus brevis)。菌株XZ5和XZ11都在8 h进入对数期,并且在生长繁殖时期产生大量酸性物质使菌液pH值降低,而较低的pH值有利于泡菜的保存。综上所述德氏乳杆菌XZ5具有发酵泡菜的益生潜能,可作为泡菜等发酵食品的微生物资源。

6种中草药提取物对火腿切片典型腐败菌的抑制研究

低温肉制品贮藏期间的微生物腐败现象引起了人们的广泛关注,针对典型腐败菌的控制研究越来越受到重视。本研究中,笔者在火腿切片贮藏期间分离纯化得到了3株典型腐败菌,选取6种中草药提取物以筛选对典型腐败菌抑菌能力较强的单味中草药,并对其进行复配,评估其抑菌效果。结果表明:6种中草药提取物中,石榴皮提取物对绿色魏斯氏菌和清酒乳杆菌的抑菌效果最好,抑菌圈直径分别为10.63和12.73 mm,最小抑菌质量浓度均为15.63~31.25 mg/mL;甘草提取物对肠膜明串珠菌的抑制效果最优,抑菌圈直径为14.68 mm,最小抑菌质量浓度为3.91~7.81 mg/mL;复配提取物中,甘草+乌梅+石榴皮的抑菌性能显著提高,对3株受试菌株均有不错的抑制效果,抑菌圈直径分别为18.17、11.55和12.74 mm。本研究可为低温肉制品中绿色健康的天然防腐剂开发提供参考。

乳酸菌生物膜的形成、特性及应用研究

大多数乳酸菌作为益生菌被人们熟知并广泛应用于食品领域。生物膜是细菌应对不利环境的自然生长状态。而近些年的相关研究揭示了乳酸菌生物膜的成膜规律和优良特性,也初步探究了乳酸菌生物膜在生产中的应用。为进一步调控和利用乳酸菌生物膜,对乳酸菌生物膜的深入研究和理解十分必要。文章综述了乳酸菌生物膜的形成、细胞黏附胞外聚合物在生物膜形成中的作用,以及乳酸菌与酵母菌的混菌生物膜形成和酵母-乳酸菌相互作用,介绍了乳酸菌生物膜在抗逆、抑菌、食品生产、人体健康等方面的应用,以期为人们了解乳酸菌生物膜和对其进行更深入的研究和应用提供帮助。

红树林植物内生菌分离鉴定及其抑菌活性研究

[目的]从红树林植物组织中分离出对动物病原菌具有广谱抑菌活性的植物内生菌。[方法]以铜绿假单胞菌、多杀性巴氏杆菌、产气肠杆菌、粪肠球菌4种常见的致病菌作为指示菌,采用M10和P3培养基从红树林植物根、茎、叶组织中分离内生菌,以固体琼脂打孔法筛选具有抑菌活性的菌株,提取菌株的基因组DNA,PCR扩增16S rDNA基因并测序,通过邻接法构建系统发育树。[结果]从红树林植物组织中共分离857株可培养的内生菌,有145株菌有抑菌活性,占分离菌株的16.6%。其中通过M10培养基从红树林植物叶组织分离的菌株32-5对铜绿假单胞菌、产气肠杆菌都具有最强抑菌活性,其抑菌圈直径分别为38和42 mm;通过P3培养基从红树林植物茎组织分离的菌株12-4对粪肠球菌具有最强抑菌活性,其抑菌圈直径为56 mm;通过M10培养基从红树林植物茎组织分离的菌株13-2对多杀性巴氏杆菌具有最强抑菌活性,其抑菌圈直径为64 mm。有抑菌活性菌株分为10个属,其中芽孢杆菌属是优势菌属。[结论]该试验初步揭示红树植物根、茎、叶组织中植物内生菌的抑菌活性和多样性,为开发新型抗菌药物及应用提供理论依据。

抑制幽门螺杆菌乳酸菌的筛选及抑菌物质的特性研究

为获得能够抑制幽门螺杆菌的乳酸菌,文章从泡菜中筛选得到10株乳酸菌,并运用牛津杯法分别对这10株乳酸菌开展抑制幽门螺杆菌的试验。其中,有3株乳酸菌具有抑菌活性,分别为PW-2、PW-5和PW-7,且菌株PW-2的抑菌直径最大。通过观察菌株形态特征,并与16S rDNA基因序列进行比对分析,确定该菌株为植物乳杆菌。对该菌中的抑菌活性物质进行研究后发现,排除乳酸和H2O_(2)后,其仍具有抑菌活性。同时,蛋白酶敏感试验表明,该菌株发酵液中的抑菌物质是蛋白质或多肽。此外,菌株PW-2中的抑菌物质在酸性条件下的抑菌活性较强,且具有一定的温度稳定性。

Improvement of antibacterial activity of copper nanoclusters for selective inhibition on the growth of gram-positive bacteria

In general, copper nanoclusters (CuNCs) possess very low or even virtually no bactericidal effect. Herein,we report a novel CuNCs possessing significantly high antibacterial activity, that is tannic acid (TA)capped CuNCs (TA-CuNCs). TA-CuNCs exhibit strong absorption and excitation-dependent fluorescence within pH 2-12, resulting from the functional groups of TA-CuNCs due to two prototropic equilibria,phenolphenolate and carboxyliccarboxylate. There exists synergistic effect of TA and copper nanoclusters which endows TA-CuNCs remarkable antibacterial capability as a microbicide, as characterized by the effective inhibition on the growth of gram-positive bacteria by damaging the cell membrane. By incubating 1 x 10~7 CFU/mL of gram-positive bacteria Staphylococcus aureus and Bacillus subtilis with 30 μg/mL of TA-CuNCs for 10 min, the bacteria are completely inhibited, while under same conditions the viabilities of gram-negative bacteria Escherichia coli 0157:H7 and Pseudomonas aeruginosa remain 85.0%, 72.0%, respectively. In addition, TA-CuNCs exhibit low cytotoxicity and favorable biocompatibility demonstrated by standard methyl thiazolyl tetrazolium (MTT) assay with HepG2 and 293 Tcells, giving rise to cell viability of 94.2% for HepG2 and 96.7% for 293 T by incubating 10~6 cell/mL with 200 μg/mL of TA-CuNCs for 24 h. These results make TA-CuNCs a potential alternative as bactericide for infection treatment caused by gram-positive bacteria.

A widespread response of Gram-negative bacterial acyl-homoserine lactone receptors to Gram-positive Streptomyces γ-butyrolactone signaling molecules

Cell-cell communication is critical for bacterial survival in natural habitats,in which miscellaneous regulatory networks are encompassed.However,elucidating the interaction networks of a microbial community has been hindered by the population complexity.This study reveals thatγ-butyrolactone(GBL)molecules from Streptomyces species,the major antibiotic producers,can directly bind to the acyl-homoserine lactone(AHL)receptor of Chromobacterium violaceum and influence violacein production controlled by the quorum sensing(QS)system.Subsequently,the widespread responses of more Gram-negative bacterial AHL receptors to Gram-positive Streptomyces signaling molecules are unveiled.Based on the cross-talk between GBL and AHL signaling systems,combinatorial regulatory circuits(CRC)are designed and proved to be workable in Escherichia coli(E.coli).It is significant that the QS systems of Gram-positive and Gram-negative bacteria can be bridged via native Streptomyces signaling molecules.These findings pave a new path for unlocking the comprehensive cell-cell communications in microbial communities and facilitate the exploitation of innovative regulatory elements for synthetic biology.

银耳多糖抑菌效果研究

采用抑菌圈试验检测古田银耳多糖对5种常见致病菌的抑菌效果,结果表明,1.87μg·mL^(-1)银耳多糖溶液对铜绿假单胞菌、乙型副伤寒沙门菌、大肠埃希菌均有一定的抑制作用,但是1.87~151.42μg·mL^(-1)银耳多糖溶液对金黄色葡萄球菌、白色念珠菌均无明显的抑制作用。

海水中细菌的分离鉴定及其对动物源病原菌的抑菌活性研究

为了分离出具有抑菌活性的海洋细菌,利用M10培养基、P3培养基和BHI固体培养基从海水样品中分离细菌,采用固体琼脂打孔法从分离细菌中筛选对大肠杆菌、铜绿假单胞菌、金黄色葡萄球菌和单增李斯特氏菌有抑菌活性的细菌,PCR扩增具有抑菌活性的细菌的16S rDNA基因并进行测序分析。结果表明,从湛江地区海水中共分离出1615株细菌,其中246株具有抑菌活性,对4种指示菌均有抑菌效果的细菌有6株。对大肠杆菌抑菌效果最佳的菌株DB17-1抑菌圈直径为26 mm,对金黄色葡萄球菌抑菌效果最佳的菌株FP5-2抑菌圈直径为29 mm,对铜绿假单胞菌抑菌效果最佳的菌株AM20-8抑菌圈直径为20 mm,对单增李斯特氏菌抑菌效果最佳的菌株FM11-1抑菌圈直径为24 mm。具有抑菌活性的细菌共分为31个属,其中不动杆菌属和芽孢杆菌属最多,分别占21.5%和18.3%。结果提示,海水中存在具有良好抑菌效果的细菌,可为发掘新型抗菌药物提供参考。

Selective inactivation of Gram-positive bacteria in vitro and in vivo through metabolic labelling

Bacterial infections are grave threats to human health,particularly those caused by the most common Grampositive bacteria.The massive administration of broad-spectrum antibiotics to treat various bacterial infections has led to the evolution and spread of drug resistance.As a universal antimicrobial technique unapt to induce drug resistance,photothermal therapy(PTT)is attracting extensive attention in recent years.However,its unspecific killing capability and side effects towards adjacent mammalian cells severely impede the practical applications.Herein,we proposed a metabolic engineering strategy to selectively inactivate Gram-positive bacteria by PTT.A bioorthogonal photothermal agent was prepared by the conjugation of IR-780 iodide and dibenzocyclooctyne(IR780-DBCO).Upon pre-metabolizing with 3-azido-D-alanine,Gram-positive bacteria rather than Gramnegative ones,such as Staphylococcus aureus and vancomycinresistant Enterococcus faecalis(VRE),could be specifically tied up by the explosive IR780-DBCO via copper-free click chemistry.Thereafter,they spontaneously detonated under 15 min near-infrared light irradiation and inactivated nearly 100% Gram-positive bacteria in vitro.Moreover,superbug VRE-induced infection was significantly inhibited by this approach in a mouse skin wound model.This metabolic labelling-based photothermal ablation strategy specific to Gram-positive microbes would stimulate the development of precise antibacterial candidates for preclinical applications.

酸汤中高产酸细菌的分离筛选及其特性研究

目的对酸汤中分离筛选的高产酸细菌进行鉴定,并研究其生物学特性。方法从白酸汤和红酸汤中分离出的细菌,通过16S rDNA基因序列分析进行分子生物学鉴定,并研究其产酸特性、生理生化特性、耐酸碱和耐盐能力,同时用牛津杯法以抑菌圈为指标,探究其抑制致病菌性能。结果筛选出4株高产酸乳酸菌和1株产酸醋杆菌,其中RS-5为甘草乳杆菌(Liquorilactobacillus nagelii),ST15-2和RS-8为布氏乳杆菌(Lentilactobacillus buchneri),ST20为发酵粘液乳杆菌(Limosilactobacillus fermentum),ST19为产液葡糖酸醋杆菌(Gluconacetobacter liquefaciens);RS-8、ST15-2、ST20和RS-5具有较高的产酸能力,产总酸均超过(103.54±6.19)g/L,RS-8产总酸量达到(159.12±12.24)g/L,经高效液相色谱法测定ST20、RS-5和ST15-2产乳酸较高,分别是10.21、9.76和7.11 mg/mL,RS-8和RS-5产柠檬酸较高,分别为4.87 mg/mL和3.93 mg/mL;RS-8、ST15-2和ST20具有较好的耐酸性、耐碱性和耐盐性;RS-5和ST20对大肠杆菌有显著抑制作用,ST15-2对金黄色葡萄球菌有显著抑制作用。结论RS-8、ST15-2、ST20和RS-5菌株高产酸且具有较好的耐酸碱和耐盐性能,有抑致病菌作用,具有一定工业化应用前景。

产细菌素海洋乳酸菌的筛选及细菌素抑菌机制

【目的】筛选海洋源产细菌素乳酸菌,探讨细菌素抑菌机制。【方法】从市售海鱼的肠道中筛选出一株对金黄色葡萄球菌(Staphylococcus aureus)和大肠埃希菌(Escherichia coli)有较强抑菌效果的菌株GOFEL226,通过16S rDNA序列鉴定乳酸菌,用乙酸乙酯提取细菌素,利用分光光度法、电导率法、扫描电镜技术探究细菌素的抑菌机制。【结果】菌株GOFEL226为戊糖乳植物杆菌(Lactiplantibacillus pentosus),GFEB226细菌素对金黄色葡萄球菌和大肠埃希菌的最小抑菌质量浓度为0.883 mg/mL;其对指示菌的生长有明显的抑制作用,可导致细胞的蛋白质、核苷酸、带电离子泄漏到细胞外,对细胞膜具有破坏作用。【结论】GFEB226细菌素可通过破坏革兰阳性和革兰阴性菌的细胞膜,使其胞内物质泄漏到胞外,进而导致细胞的死亡。

牡丹拮抗内生细菌的筛选及发酵条件优化研究

以牡丹根部组织为材料,对其根部内生细菌进行分离纯化,筛选出能够对金黄色葡萄球菌产生拮抗作用的菌株,并根据常规分类学结合16S rRNA对筛选出的菌株进行鉴定.通过单因素试验和正交试验确定了培养基成分的最佳组合,并对发酵条件进行了优化.结果表明:菌株mudan-6对金黄色葡萄球菌的拮抗作用最好,抑菌圈直径为(20±0.3)mm,经测序鉴定该菌株为产气克雷伯氏菌(Klebsiella aerogenes);最佳培养基组合为0.5%蔗糖,1.5%酵母浸粉,1%碳酸钙;最佳发酵条件为接种量5%,发酵温度37℃,pH值9.0,装液量100 mL,转速180 r/min,培养时间12 h.

枯草芽孢杆菌H6-1的生防及促生效果研究

【目的】为深入发掘微生物在农业领域的应用,本研究从生防和促生两方面探究菌株H6-1在农业上的应用效果。【方法】本研究提供一株细菌,编号H6-1;通过对菌株的16S rRNA鉴定初步确定该菌株属枯草芽孢杆菌(Bacillus subtilis);将该菌株与多种病原真菌进行平板对峙抑菌测定,对菌株进行多作物促生实验,并进行生理生化测定分析。【结果】该菌株可抑制多种病原真菌的生长,平均抑制率在70%以上;对桉树小苗、快菜的生长有促进效果;具有蛋白酶、纤维素酶、过氧化氢酶、铁载体活性,可溶解难溶性磷;过氧化氢酶活性达333μg·mL^(-1)·min^(-1),无机磷溶磷量51.7 mg·L^(-1)。【结论】本研究的枯草芽孢杆菌兼具生防和促生两大效果,具有高效、广谱的抑菌活性和多样化的生物活性,能促进作物生长发育,在农用微生物领域具有潜在应用前景。