Sophoraflavanone G from sophora pachycarpa enhanced the antibacterial activity of gentamycin against Staphylococcus aureus

In this study the enhancement effect of Sophora pachycarpa roots' acetone extract on the antibacterial activity of gentamycin was evaluated against Staphylococcus aureus. Disc diffusion and broth dilution methods were used to determine the antibacterial activity of gentamycin in the absence and presence of plant extract and its various fractions separated by TLC. A clinical isolate of S. aureus was used as test strain. The active component of the plant extract involved in enhancement of gentamycin's activity had Rf = 0.72 on a TLC plate. The spectral data (1H NMR, 13C NMR) of this compound revealed that this compound was 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone (sophoraflavanone G), previously isolated from Sophora exigua. In the presence of 0.03 microg/ mL of sophoraflavanone G the MIC value of gentamycin for S. aureus decreased from 32 to 8 microg/mL (a four-fold decrease). These results signify that the ultra-low concentration of sophoraflavanone G potentiates the antimicrobial action of gentamycin suggesting a possible utilization of this compound in combination therapy against Staphylococcus aureus.     

Susceptibility to antibiotics of Ureaplasma urealiticum strains isolated at the primorye region]

Susceptibility to antibiotics of Ureaplasma urealyticum strains isolated in Primorye Region and its changes were evaluated. Among the sexually transmited diseases urogenital ureaplasmosis has the leading position in combination with gonorrhoea, trichomoniasis and infections caused by opportunistic pathogens. The spectrum of investigated antibacterial agents included gentamycin, clarithromycin, roxythromycin, azithromycin, doxycycline, three fluoroquinolones of II generation and for cephalosporins of the I and III generations. The most potent activity against U. urealyticum was demonstrated for pefloxacin (67 per cent of susceptible strains), ofloxacin (63 per cent) and roxythmycin (54 per cent). It is concluded that at Primorye Region the drugs of first choice for the urogenital infections therapy are fluoroquinolones.     

Multifactorial aspects of antimicrobial activity of propolis

We investigated the antibacterial activity of sub-inhibitory concentrations of ethanolic extract of propolis (EEP), and its effect on the antibacterial activity of some antibiotics. Some clinically isolated Gram-positive strains were used.

Moreover, sub-inhibitory concentrations of EEP were used to value its action on some important virulence factors like lipase and coagulase enzymes, and on biofilm formation in Staphylococcus aureus.

Our results indicated that EEP had a significant antimicrobial activity towards all tested clinical strains.

Adding EEP to antibacterial tested drugs, it drastically increased the antimicrobial effect of ampicillin, gentamycin and streptomycin, moderately the one of chloramphenicol, ceftriaxon and vancomycin, while there was no effect with erithromycin.

Moreover, our results pointed out an inhibitory action of EEP on lipase activity of 18 Staphylococcus spp. strains and an inhibitory effect on coagulase of 11 S. aureus tested strains.

The same EEP concentrations showed a negative interaction with adhesion and consequent biofilm formation in S. aureus ATCC 6538P.     

Antibacterial activity of multiple antigen peptides homologous to a loop region in human lactoferrin.

An 11-residue peptide (FQWQRNMRKVR) homologous to just over half the loop region of human lactoferricin is thought to be responsible for antimicrobial properties of human lactoferricin. Multiple antigen peptides (MAP) of the 11-residue peptide exerted significant antibacterial effects against a broad spectrum of bacteria including MRSA. More than eight branching was favourable for increasing its antibacterial activity. Our report shows a novel possibility for MAP to increase the activity of antibiotic peptides other than simply to stimulate antibody production, as reported so far.     

Design,Microwave‐Assisted Synthesis and in Vitro Antibacterial and Antifungal Activity of 2,5‐Disubstituted Benzimidazole

Seventeen novel 2,5‐disubstituted benzimidazole derivatives were designed, synthesized and evaluated for their antibacterial activities. The tested compounds B1 – B4 and C2 – C6 exhibited not only good antifungal activity but also favorable broad‐spectrum antibacterial activity. Also, the lowest MIC of antibacterial and antifungal activity was 2 μg/mL and 4 μg/mL, respectively. It suggested that the structure of compound including the different substituent and its sites directly affected the efficacy of the synthesized compounds.     

The antimicrobial activity and acute toxicity of the polymer salts of gentamycin]

By neutralization of copolymers of N-(2-hydroxypropyl) methacrylamide with acrylic acid and copolymers of N-vinylpyrrolidone with crotonic and p-crotonoylaminophenoxyacetic acids in the presence of gentamycin, water-soluble polymer salts containing from 10 to 25 mass% of gentamycin were obtained. These salts regardless of gentamycin content completely retain high level of antimicrobial activity of gentamycin against Staphylococcus spp. and Escherichia coli and are characterized by less (by more than one order of magnitude) acute toxicity.     

肠球菌E4及其抑菌产物特性的研究

目的获得抑制微生物生长的菌株。方法根据形态学和生理生化学特性进行菌种鉴定;采用牛津杯法测定抑菌谱和抑菌物质的理化特性。结果排除了过氧化氢和有机酸的作用,该菌发酵上清液对苏云金杆菌、枯草杆菌、大肠埃希菌、鸡白痢沙门菌等有抑制作用。根据菌株的生理生化特征,该菌株初步定为肠球菌属,定名为E4（Enterococcus sp．）。所产抑菌物质具有较好的热稳定性,在酸性条件下稳定且活性高。结论分离筛选了1株可产抑菌物质的肠球菌,其产生的抑菌物质具有良好的生物化学特性和广谱的抑菌能力。     

Experimental study of the antibacterial activity and chemotherapeutic efficacy of the novel glycopeptide eremomycin

The study of antibacterial and chemotherapeutic activity of eremomycin, a novel glycopeptide antibiotic showed that it inhibited the growth of gram positive and acid fast microbes. The antibacterial spectrum of the novel glycopeptide was close to that of ristomycin and vancomycin. However, the in vitro antibacterial activity of eremomycin was 2-10 times higher than that of ristomycin and vancomycin. It also inhibited the growth of oxacillin resistant microbes at concentrations 5.20 times lower than those of vancomycin and ristomycin. By the therapeutic efficacy in albino mice with staphylococcal or streptococcal sepsis eremomycin was 2-4 times as superior as vancomycin and ristomycin and by the chemotherapeutic indices it was more than 10 times as superior.     

Study of the antiviral action of gentamicin]

Experimental data on the effect of various concentrations of gentamycin on reproduction of VEE and Sindbis viruses in tissue culture are presented. It was found that gentamycin had no cytotoxic effect on the primary tripsinized chick embryon fibroblasts (CEF) when used in doses of 10, 20 or 30 mg/ml and only when used in a dose of 50 mg/ml it induced 50 percent destruction of the cell layer. Multiplication of the VEE and Sindbis viruses in the culture of CEF was inhibited in the presence of gentamycin by 1.5--3.5 lg PFU/ml. Two stages in the virus inhibiting effect of gentamycin were determined on the model of VEE, i. e. the stage of inhibition in the absence of visible damages of the cells and the stage associated with their destruction. The doses of gentamycin higher than 3 mg/ml inhibited in parallel the virus specific synthesis and synthesis of the cell proteins and nucleic acids. At the same time, when gentamycin was used in a dose of 10 mg/ml, no impairement of the cell viability was observed and the cell capacity to produce high titers of the model virus was reduced after incubation without the antibiotic for 24 hours. The antiviral activity of gentamycin were therefore determined by revers inhibition of the cell metabolic activity.     

贮存年份对北艾和蕲艾精油成分与抑菌活性的影响研究

本文采用水蒸汽蒸馏法提取了贮存0、1、2年的北艾和蕲艾精油,采用GC-MS检测精油化学成分,选取10种常见细菌,检测了其抗菌谱和最小杀菌浓度。结果发现:0、1年份北艾精油中小分子挥发性物质较多,随着贮存年份的增加,大分子挥发性物质随之增加;侧柏酮为蕲艾的特有成分。0年份艾叶精油的抑菌活性较高,对沙门菌、枯草芽孢杆菌、沙门菌耐药菌、绿脓杆菌均具有抑制作用。综上,不同贮存年份和品种的艾叶精油在化学成分、抗菌谱和抑菌活性方面均存在差异,综合考虑精油含量和抑菌活性,以0年份的北艾为原料提取精油最佳。     

The antimicrobial activity of Augmentin (amoxicillin/clavulanic acid) compared to other antibacterial agents]

Sensitivity of clinical strains of gram-positive and gram-negative bacteria to Augmentin was studied in comparison to other antibiotics. Augmentin was shown to be advantageous in the level and spectrum of its antibacterial activity over ampicillin and other broad-spectrum antibiotics.     

中蜂抗菌物质的诱导

本文报道了用大肠杆菌注射处理中蜂Ａｐｉｓ ｃｅｒａｎａ Ｆａｂｒｉｃｉｕｓ后,用含菌培养基平板测活法,就中蜂抗菌物质的产生规律及抗菌活性进行了初步研究。结果表明,不同诱导源均可诱导中蜂产生抗菌物质,但诱导的抗菌物质的抗菌活性则有一定的差异。用大肠杆菌重复诱导则使中蜂的成活率和抗菌物质的抗菌活性有很大提高。注射大肠杆菌后冲蜂抗菌物持产生高峰在４８小时左右。诱导后产生的抗菌物质具有广谱性,对大肠杆菌Ａｓｃｈｅｒｉｃｈｉａ　ｃｏｌｉ、枯草芽孢杆菌 Ｂａｃｉｌｌｕｓ　 ｓｕｂｔｉｌｉｓ、苏云金杆菌 Ｂａｃｉｌｌｕｓ　ｔｈｕｒｉｎｇ－ｉｅｎｓｉｓ、巨大芽孢杆菌 Ｂａｃｉｌｌｕｓ　ｍｅｇａｔｈｅｒｉｕｍ、黑腐菌 Ｘａｎｔｈｏｍｏｎａｓ ｃａｍｐｅｓｔｒｉｓ　等均有抑菌作用,而对真菌白僵菌Ｂｅａｕｖｅｒｉａ　ｂａｓｓｉａｎａ未发现抑菌作用。中蜂麻醉方法以冷冻法最为简便、易行。     

抗菌肽及抗菌肽转基因植物研究进展

抗菌肽是一类小分子多肽,在生物体内分布广泛,具有广谱的抗菌性,是生物体内天然防御系统的一部分。主要介绍了抗菌肽的性质,类型,作用机制及抗菌肽转基因植物的研究进展。     

一种猪溶菌酶来源的抗菌六肽的分离鉴定及其性质

为提高猪溶菌酶(Sus scrofa lysozyme,SSL)的抗革兰氏阴性菌活性,将其进行了不同蛋白酶的水解,选择抗革兰氏阴性菌效果最好的水解产物,利用凝胶过滤色谱和反相制备色谱进行分离,对其功能成分进行液质联用鉴定。对分离得到的物质进行抗菌活性验证和生物信息学的分析,并在此基础上对抗菌物质的杀菌机理进行了探讨。结果表明,胰蛋白酶的水解产物具有较高的杀灭革兰氏阴性菌的活性,进一步分离纯化得到了具有抗革兰氏阴性菌活性的六肽A-W-V-A-W-K。经化学合成验证,该六肽既保留了SSL的部分抗菌活性,也具备杀灭多种革兰氏阴性菌的能力。进一步分析发现其位于SSL分子C端的一个螺旋-回环-螺旋的结构中,并由此推测其杀菌机理是通过改变细胞膜的渗透性,进而使细胞内溶物流出而造成细胞死亡,而抗菌实验也验证了这一推测。该抗菌肽的发现为后续提高SSL的抗菌活性提供了理论依据。     

Haloprogin: a Topical Antifungal Agent

Haloprogin was shown to be a highly effective agent for the treatment of experimentally induced topical mycotic infections in guinea pigs. Its in vitro spectrum of activity also includes yeasts, yeastlike fungi (Candida species), and certain gram-positive bacteria. The in vitro and in vivo antifungal activity of haloprogin against dermatophytes was equal to that observed with tolnaftate. The striking differences between the two agents were the marked antimonilial and selective antibacterial activities shown by haloprogin, contrasted with the negligible activities found with tolnaftate. Addition of serum decreased the in vitro antifungal activity of haloprogin to a greater extent than that of tolnaftate; however, diminished antifungal activity was not observed when haloprogin was applied topically to experimental dermatophytic infections. Based on its broad spectrum of antimicrobial activity, haloprogin may prove to be a superior topical agent in the treatment of dermatophytic and monilial infections in man.     

脑细胞生长肽对GM耳毒性的预防作用

目的：观察脑细胞生长肽（cerebral cell growth peptide,CCGP)对庆大霉素（gentamicin,GM)引起的豚鼠耳中毒的预防作用）。方法：用脑干听觉诱发电位（brainstem auditory evoked potential,BAEP)和组织化学方法分别检测动物听阀的变化和耳蜗毛细胞线粒体内琥珀酸脱氢酶（succinate dehydrogenase,SDH)及溶酶体内的酸性磷酸酶（acid phosphatase,ACP)活性变化,并在三组动物进行耳蜗受损毛细胞计数。结果：CCGP能降低GM引起的BAEP反应阈的上升幅度,保护耳蜗毛细胞SDH和维持溶酶体的完整性,减轻毛细胞的损伤。结论：CCGP能降低GM的中毒性;保护耳蜗毛细胞SDH,维持毛细胞的能量代谢,减少溶酶体损伤,降低溶酶体内水解酶逸出引起的毛细胞自溶性损伤,可能是CCGP预防GM耳毒性的机制之一。     

Assessment of diversity,distribution and antibacterial activity of endophytic fungi isolated from a medicinal plant <Emphasis Type="Italic">Adenocalymma alliaceum</Emphasis> Miers

A study was conducted for isolation, identification and antibacterial potential of fungal endophytes of Adenocalymma alliaceum Miers., (Bignoniaceae), a medicinal shrub vine plant which has long history for its usages in curing various disorders. A total of 149 isolates of endophytic fungi representing 17 fungal taxa were obtained from 270 segments (90 from each stem, leaf and petiole) of this plant. Hyphomycetes (77.85%) were the most prevalent, followed by Ascomycetes (8.05%) and Coelomycetes (4.03%) respectively. A considerable amount of fungal isolates was kept under (10.07%) Mycelia-Sterilia (MS). Leaf harboured maximum colonization of endophytic fungi (72.22%) which was greater than stem (67.78%) and petiole (25.54%). The Jc similarity index was maximum (0.619) between stem vs leaf followed by leaf vs petiole (0.571) and stem vs petiole (0.428). The dominant endophytic fungi were Alternaria alternata, Aspergillus niger, Stenella agalis, Fusarium oxysporum, Curvularia lunata and Fusarium roseum. Among twelve endophytic fungi tested for antibacterial activity, crude extracts of nine endophytic fungi (75%), showed antibacterial potential against one or more clinical human pathogens. Alternaria alternata, Curvularia lunata, Penicillium sp. and Chaetomium globosum exhibited significant antibacterial activity against 4 of 5 tested pathogens, showing broad spectrum activity. This investigation explains the value of sampling from different tissues of a host plant for the greater species diversity, and additionally, the antibacterial screening of some endophytic fungi from this specific medicinal plant may represent a unique source for many of the useful antibacterial compounds.     

Bacteriocinogenic activity of strains of the genus Erwinia

Antibacterial activity of 272 Erwinia strains was studied. It was found that 182 or 66.9 per cent of the strains were capable of producing spontaneously antibacterial substances belonging to the class of bacteriocins; 125 bacteriocynogenic strains were divided into 25 groups on the basis of their antibacterial spectrum similarity; 57 bacteriocynogenic strains were not included into any of these groups because of their significant heterogenicity with respect to the feature studied. It was shown that most of the strains inhibited viability of the bacteria of both its own and other species. Investigation of the antagonistic activity of the Erwinia strains with broad antibacterial spectra with respect to E. coli indicative for colicins gave negative results. The study of the Erwinia strains sensitivity to the antibacterial effect of the bacteriocynogenic cultures showed that 210 out of 272 cultures were sensitive to separate bacteriocins.     

Antimicrobial effects of sanitizers against planktonic and sessile Listeria monocytogenes cells according to the growth phase

An entomopathogenic bacterium, Xenorhabdus nematophila, is known to have potent antibiotic activities to maintain monoxenic condition in its insect host for effective pathogenesis and ultimately for optimal development of its nematode symbiont, Steinernema carpocapsae. In this study we assess its antibacterial activity against plant-pathogenic bacteria and identify its unknown antibiotics. The bacterial culture broth had significant antibacterial activity that increased with development of the bacteria and reached its maximum at the stationary growth phase. The antibiotic activities were significant against five plant-pathogenic bacterial strains: Agrobacterium vitis, Pectobacterium carotovorum subsp. atrosepticum, P. carotovorum subsp. carotovorum, Pseudomonas syringae pv. tabaci, and Ralstonia solanacearum. The antibacterial factors were extracted with butanol and fractionated using column chromatography with the eluents of different hydrophobic intensities. Two active antibacterial subfractions were purified, and the higher active fraction was further fractionated and identified as a single compound of benzylideneacetone (trans-4-phenyl-3-buten-2-one). With heat stability, the synthetic compound showed equivalent antibiotic activity and spectrum to the purified compound. This study reports a new antibiotic compound synthesized by X. nematophila, which is a monoterpenoid compound and active against some Gram-negative bacteria.     

Effect of some antibiotics on semi-circular canal activity in the frog (Rana esculenta)]

We have studied the action of two ototoxic antibiotics (streptomycin and gentamycin) on the activity of the horizontal semicircular canal in comparison with those of penicillin and 7 g/1 NaCl solution, all of them being injected into the labyrinthic cavity. Only streptomycin and gentamycin have a specific action, and the one of streptomycin is much more important than the one of gentamycin.