The antibacterial activity of selected plants towards resistant bacteria isolated from clinical specimens

Objective:To evaluate the antibacterial activity of eight plants against methicillinresistant Staphylococcus aureus(MRSA),extended spectrum beta-lactamase and carbapenemase-resistant Enterobacteriaceae,which are the most prevalent causes of infections in inpatients.Methods:The antibacterial activity was calculated based on the minimum inhibitory concentration using Mueller-Hinton broth in a microdilution method.Results:The best antibacterial activity,calculated as minimum inhibitory concentration values,against MRSA was shown by the Kaempferia pandurata(Roxb)(K.pandurata)extract(256 μg/mL) and the Senna alata(S.alata) extract(512 μg/mL).Phytochemical screening of dried S.alata leaf and its extract showed the presence of flavonoids,alkaloids,saponins,quinones,tannins and sterols,while dried K.pandurata and its extract only showed the presence of flavonoids and sterols/triterpenoids.Conclusions:K.pandurata and S.alata have the potential to be developed as antibacterial agents,especially against MRSA strain,but further in vivo research and discovery of the mode of its action are still needed to shed light on the effects.

Evaluation of Various Crude Extracts of <i>Zingiber officinale</i>Rhizome for Potential Antibacterial Activity: A Study <i>in Vitro</i>

In vitro antibacterial activity of crude aqueous and organic extracts of rhizome of Zingiber officinaleRoscoe (ginger) was studied against both Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Streptococcus pyogenes) bacterial strains. The present study reveals that the pattern of inhibition varied with the solvent used for extraction and the organism tested. Plant extracts prepared in organic solvents provided more consistent antibacterial activity as compared to aqueous extracts. Methanol extract was the most active against maximum number of bacterial species tested. Gram-positive bacteria were found the most sensitive as compared to Gram-negative bacteria. Staphylococcus aureus was significantly inhibited by almost all the extracts even in very low MIC followed by other Gram-positives. Escherichia coli (a Gram-negative bacterium) was showing the least inhibition with highest MIC values, while Salmonella typhi was found completely resistant. Methanol extract yielded the presence of terpenoids, flavonoids, alkaloids and tannins in phytochemical screening. Results of the present study sign the interesting assurance of designing a potentially active antibacterial agent from Zingiber officinale.

Synergistic effect between cryptotanshinone and antibiotics in oral pathogenic bacteria

Cryptotanshinone (CT), a major tanshinone of medicinal plant Salvia miltiorrhiza Bunge, demonstrated effective in vitro antibacterial activity against all oral bacteria tested in this experiment. The antibacterial activities of CT against oral bacteria were assessed using the checkerboard and time-kill methods to evaluate the synergistic effects of treatment with ampicillin or gentamicin. The CT was determined against oral pathogenic bacteria with MIC and MBC values ranging from 0.5 to 16 and 1 to 64 μg/mL;for am- picillin from 0.0313 to 16 and 0.125 to 32 μg/mL;for gentamicin from 2 to 256 and 4 to 512 μg/mL respectively. The range of MIC50 and MIC90 were 0.0625 - 8 μg/mL and 1 - 64 μg/mL, respectively. The combination effects of CT with antibiotics were synergistic (FIC index < 0.5) against tested oral bacteria except additive, Streptococcus sobrinus, S. criceti, and Actinobacillus actinomycetemcomitans (FIC index < 0.75 - 1.0). The MBCs were shown reducing ≥4 - 8-fold, indicating a synergistic effect as defined by a FBCI of ≤0.5. Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after 3 - 6 h of treatment with the 1/2 MIC of CT, regardless of whether it was administered alone or with ampicillin or gentamicin. The results suggest that CT could be employed as a natural antibacterial agent against cariogenic and periodontopathogenic bac- teria.

中药混合液对耐甲氧西林金黄色葡萄球菌的体外抗菌作用的研究

目的探究中药混合液对耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus Sureus,MRSA)的体外抗菌作用。方法选取2022年1月—2023年6月江苏省启东市中医院检验科临床分离的40株MRSA。万古霉素、中药混合液对MRSA的体外最低抑菌浓度(Minimum Inhibitory Concentration,MIC)值采用微量肉汤稀释法测定;用K-B纸片扩散法测定万古霉素和中药混合液对MRSA的抑菌效果,探究不同药物浓度对MRSA抑菌活性的影响。结果万古霉素MIC值为(1.56±0.55)mg/L,低于中药混合液的(1.63±0.62)mg/mL,差异有统计学意义(P<0.05)。万古霉素抑菌圈直径为(20.56±0.87)mm,优于中药混合液的(19.89±0.73)mm,差异有统计学意义(P<0.05)。抑菌圈直径大小随浓度增加而增大且中药混合液各浓度抑菌圈直径均大于万古霉素,差异有统计学意义(P均<0.05)。结论中药混合液对MRSA的体外最低抑菌浓度极低,可以有效抑制耐甲氧西林金黄色葡萄球菌的生长。

In-vitro antimicrobial activity screening of some ethnoveterinary medicinal plants traditionally used against mastitis,wound and gastrointestinal tract complication in Tigray Region,Ethiopia

Objective:To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis,wound and gastrointestinal complications.Methods:Hydroalcoholic exctracts of medicinal plants namely,Achyranthes aspera(A.aspera) L.(Family Asparagaceae),Ficus caria(F.caria)(Family Moraceae).Malvi parviflora(M.parviflora)(Family Malvaceae),Vernonia species(V.species) docal name Alakit.Family Asteraceae),Solatium hastifolium(S.hastifolium)(Family Solanaceae),Calpurinia aurea(C.aurea)(Ait) Benth(Family Fabaceae),Nicotiana tabacum(N.tabacum) L.(Family Solanaceae),Ziziphus spina-christi(Z.spina-christi)(Family Rhamnaceae).Croton macroslachys(C.macrostachys)(Family Fuphorhiaceae).were screened against clinical bacterial isolates of veterinary importance from October 2007 to April2009.The antibacterial activity was tested using disc diffusion at two concentrations(200 mg/mL and 100 mg/mL) and broth dilution methods using 70%methanol macerated leal extracts.Results:With the exception ol S.hastifolium all plant extracts exhibited antibacterial activity.Among the medicinal plants tested C.aurea.C.macrostachyus,A.aspera,N.tabacum and vcrnonia species(Alakit) showed the most promising antimicrobial properties.Conclusions:It can be concluded that many of the tested plants have antibacterial activity and supports the traditional usage of the plants for mastitis,wound and gastrointestinal complications treatment.Further studies into their toxicity and phytochemistry is advocated.

氮杂尿苷对三株腐败菌抑菌活性的测定

目的:以二酮哌嗪为母核,对其结构修饰得到的30种化合物进行抑菌活性筛选,找到对大肠杆菌(E.coli)、腐败希瓦氏菌(Shewanella spp.)和铜绿假单胞菌(P.aeruginosa)抑菌效果理想的化合物。方法:首先采用紫外吸收光谱法定期测定放入光照振荡培养箱中菌悬液和营养肉汤的吸光度,得到三株腐败菌的生长曲线。其次采用纸片琼脂扩散法对药物的抑菌活性进行筛选,从30种化合物中筛出有抑菌效果的化合物。最后采用肉汤稀释法结合紫外分光光度计测定最低抑菌浓度(Minimum Inhibitory Concentration, MIC)。结果:氮杂尿苷对三株腐败菌的MIC均为3.42 mg/mL,且抑菌效果随着药物浓度的增大而增大。结论:氮杂尿苷对三种腐败菌具有较为显著的抑菌作用,这为后期防腐保鲜剂的研发提供了一定数据参考和理论支持。

基于cBD3的衍生肽对犬皮肤源多药耐药菌的抑菌活性

[目的]筛选犬皮肤源多药耐药菌,同时基于犬防御素设计衍生肽并探究其抗菌作用。[方法]通过K-B药敏纸片法对临床分离的菌株进行筛选,随后以犬β-防御素3(cBD3)的氨基酸序列为模板,采用氨基酸替换的方式对序列进行设计,选取优化肽cBD3-ABU进行化学合成,利用微量肉汤稀释法检测cBD3-ABU对多药耐药菌的抑菌活性。[结果]筛选获得8株犬皮肤源多药耐药菌;通过固相合成法获得纯度达95.61%的cBD3-ABU;cBD3对大肠杆菌、表皮葡萄球菌、伪中间型葡萄球菌和金黄色葡萄球菌的最小抑菌浓度分别为32、64、64、128μg/mL,高浓度cBD3-ABU对犬皮肤源大肠杆菌、表皮葡萄球菌、伪中间型葡萄球菌、金黄色葡萄球菌的抑菌率分别为96.02%、81.85%、87.25%、98.91%。[结论]cBD3-ABU在体外具有良好的抑菌活性,具有进一步开发为治疗性药物的潜力。

迷迭香粗提物提取工艺优化及其抑菌活性

迷迭香具有抑菌、抗氧化等生物活性,为获得有效抑菌成分,该研究通过单因素试验结合响应面试验优化迷迭香粗提物提取工艺;利用牛津杯法和滤纸圆片法对迷迭香粗提物抑菌作用进行研究,并确定其最低抑菌浓度。研究结果表明:迷迭香粗提物提取最优工艺条件为液料比7∶1(mL/g)、提取温度78℃、提取时间62 min、乙醇浓度60%、提取次数3次,在此条件下,迷迭香粗提物得率为(32.40±0.52)%。抑菌试验结果表明,迷迭香粗提物对食品中常见致病菌(如大肠杆菌、金黄色葡萄球菌、绿脓杆菌、蜡样芽孢杆菌)均具有较好的抑制作用,对大肠杆菌、金黄色葡萄球菌、绿脓杆菌、蜡样芽孢杆菌的抑菌圈直径分别为15.12、22.15、23.22、9.58 mm,最低抑菌浓度分别为50.0、12.5、25.0、25.0 mg/mL。

复配精油抑菌剂的制备及其对鲜切猪肉的抑菌作用

通过水蒸气蒸馏法提取肉桂精油(cinnamon essential oil,CEO)、紫苏精油(perilla essential oil,PEO)和牛至精油(oregano essential oil,OEO),采用微量二倍稀释法测定单一植物精油的最小抑菌浓度(minimal inhibitory concentration,MIC),用棋盘稀释法计算复配精油的分级抑菌浓度指数,并探究复配精油的抑菌效果及对鲜切猪肉的保鲜抑菌作用。结果表明,3种精油对大肠杆菌及金黄色葡萄球菌均有抑菌作用,抑菌能力的大小表现为肉桂精油>紫苏精油>牛至精油;精油复配后存在协同或相加现象,其中,肉桂-紫苏精油复配剂对2种供试菌种的抑菌效果显著优于肉桂-牛至精油复配剂和紫苏-牛至精油复配剂。肉桂-紫苏精油复配在一定程度上能有效抑制鲜切猪肉水分及蛋白质含量的损耗,抑制微生物生长并保持鲜猪肉的色泽,证明肉桂-紫苏精油复配剂对鲜切猪肉具有一定的保鲜抑菌作用。

大蒜水提物对几种常见微生物的生长抑制研究

大蒜是一种常用的日常调味食品,其味道辛辣且具有强烈的蒜臭味。大蒜中含有丰富的营养物质,如硫醚化合物、糖类、脂类、氨基酸类、酶类以及维生素和微量元素。大蒜不但有丰富的营养价值,还具有多方面的生物活性,如防治心血管疾病、降血脂、抗肿瘤、抗氧化清除自由基等,同时具有抗菌作用,对细菌、真菌及病毒等感染均有一定的疗效。文章采用常温提取法、酶解法、微波炉法三种方法对枯草芽孢杆菌、金黄葡萄球菌、大肠杆菌、青霉菌、曲霉菌进行抑菌实验,通过分析抑菌数据,比较每种方法对五种菌的抑菌效果。分析不同提取工艺对抑菌效果的影响,为今后开发天然抑菌剂提供科学依据,提高大蒜的利用价值。

Antimicrobial activities of the rhizome extract of Zingiber zerumbet Linn

Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol(4.0 L)after concentration.The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract(15.0 g),petroleum ether fraction(6.6 g)and chloroform soluble fraction(5.0 g).The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method.Commercially available kanamycin(30μg/disc)was used as standard disc and blank discs impregnated with the respective solvents were used as negative control.Results:At a concentration of 400μg/disc,all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm.Among the tested samples,the crude ethanol extract showed the highest activity against Vibrio parahemolyticus(V.parahemolyticus).The minimum inhibitory concentration(MIC)of the crude ethanol extract and its fractions were within the value of 128-256μg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V.parahemolyticus(128μg/mL).Conclusions:It can be concluded that,potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z.zerumbet(L.).

Development of Topical Antimicrobial Gel Containing Beehive Extract

This study aimed to determine the antimicrobial activity of beehive extract and developed topical antimicrobial gel. The beehives were extracted with three different solvents： distilled water, 50% ethanol and 95% ethanol, then each filtrate was evaporated by vacuum rotary evaporator to obtain crude extracts： water extract （W）, water-ethanol extract （WE） and ethanol extract （E）. These extracts were tested for their antimicrobial activity against five bacterial strains： Escherichia coli （ATCC 25922）, Psuedomonas aeuruginosa （ATCC 27853）, Staphylococcus aureus （ATCC 25923）, Methicillin Resistance Staphylococcus aureus （MRSA） and β-hemolytic Streptococcus group A （GAS）, then they were evaluated for their MIC and MBC values. The results revealed that the yield of the W, WE and E extracts amounted to 16.25%, 14.42% and 6.67%, respectively. Whereas, all of the samples were found to be effective against P. aeuruginosa, S. aureus, MRSA and GAS, but they were ineffective against E. coli. The W extract exhibited the highest antimicrobial activity with MIC values of 31.25-62.50 mg/mL and MBC values of 62.50 mg/mL. Then the gel bases using different gelling agents such as carbopol, hydroxyethylcellulose （HEC） and hydroxypropyl methylcellulose （HPMC） were formulated and evaluated for their physical properties： appearance, texture, pH, spread ability and stability. The formula which contained HEC was selected to incorporate with the W extract due to its smooth texture, good spreadability on the skin and good stability. The W gel exhibited a promising antimicrobial activity in both before and after stability test and also expressed no skin irritation.

金荞麦的抑菌活性研究

采用试管稀释法和管碟法分别研究了金荞麦(Fagopyrum dibotrys)根状茎和茎叶不同溶剂提取物对6种细菌和13种真菌的体外抑菌作用。结果显示,金荞麦对细菌和真菌均有一定的抑制作用。对细菌的抑菌效果表明:各种提取物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、苏云芽孢杆菌、卡拉双球菌都有明显的抑菌作用,但是对5406放线菌只有根乙醇提取物和茎叶水提取物有一定的抑制效果。对真菌的抑菌效果表明:各种提取物对鞭毛菌、白色念珠菌、松赤枯病菌、玉米纹枯病菌、油菜菌核病菌、玉米弯胞杆菌、小麦赤霉病菌、绿色木霉都有明显的抑菌作用。

新型油田回注水杀菌剂的杀菌特性

为了解决油田回注水杀菌剂苯扎氯铵[1227]的耐药性问题,合成了一种新型的双子结构季铵盐,4,4′-(1,5-戊撑二羟基)双(1-碘化十二烷基吡啶),命名为PA-12.研究了该季铵盐对于硫酸盐还原菌、铁细菌和腐生菌的杀菌特性.结果表明:PA-12的最低杀菌质量浓度与传统的油田回注水杀菌剂1227相比低一个数量级,对于硫酸盐还原菌、铁细菌和腐生菌的平均达到了5.2mg/L.PA-12对于环境温度和pH的变化都能够保持杀菌活性的稳定性.即使在10℃时PA-12的最低杀菌质量浓度也不高于60mg/L,对于油田回注水的杀菌作业具有实际意义.pH几乎不影响PA-12的杀菌能力.

微量肉汤稀释法测定长裙竹荪多种提取物对食品中常见细菌的抑制效果

选取长裙竹荪为样品,采用索氏抽提后水蒸馏萃取获得挥发油,同时分别以乙醇、正丁醇、石油醚等有机溶剂萃取得到相应提取物。以8种食品中常见细菌为供试对象,由微量肉汤稀释法测得各类提取物对其的MIC值,作为评价其抑菌效果的指标。结果表明:纯培养环境下,挥发油的抑菌效果优于三种有机溶剂提取物。通过与平板涂布计数结果及其它方法比较分析,进一步证明肉汤稀释法作为测定抑菌效果所具有的优越性。

38味中药对猪大肠杆菌的体外抑菌活性

筛选对临床分离多重耐药猪大肠杆菌有抑菌、杀菌作用的中药,并分析部分中药的联合抑菌效果。选用标准菌株ATCC83707作为对照菌株,采用纸片法测定分离菌株对临床常用抗生素的敏感性。微量2倍稀释法和平板法测定各味中药的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。微量棋盘稀释法测定2种中药的联合抑菌效果。结果表明,临床分离大肠杆菌对阿米卡星、庆大霉素、左氟沙星、青霉素G、链霉素、阿莫西林都耐药,仅对多黏菌素B呈现敏感。临床分离大肠杆菌对黄连等12味中药表现为中度敏感,对其他中药表现为不敏感;ATCC83707对黄连等10味中药中度敏感,对其他药物不敏感。黄连-芦荟、黄连-诃子、山楂-芦荟、山楂-诃子、山楂-诃子、芦荟-乌梅、诃子-白头翁等联合应用时,对临床分离大肠杆菌菌株呈现协同作用;黄连-山楂、黄连-乌梅、黄连-白头翁、山楂-香薷、芦荟-五味子、乌梅-香薷、乌梅-诃子、黄芩-诃子、诃子-五味子等联合应用时,对临床分离大肠杆菌菌株呈现相加作用;黄连-香薷、黄连-五味子等联合应用时,对临床分离大肠杆菌菌株呈现无关作用;其余药物联合应用时,对临床分离大肠杆菌菌株呈现拮抗作用。临床分离大肠杆菌对常用抗生素呈现了多药耐药趋势,但对中药仍然保持一定的敏感性;抗菌方面,中药之间存在着复杂的相互作用,部分中药间有协同作用,临床用药时须谨慎筛选。

12种中草药抑菌作用研究

筛选了乌梅、金银花、蒲公英、紫草、牡丹皮等12种可用于食品的中草药,采用水提或醇提法制备中药提取液,以大肠杆菌、金黄色葡萄球菌、沙门氏菌、枯草芽孢杆菌这4种常见食源性致病菌为供试菌,采用牛津杯法进行体外抑菌实验。结果表明:艾叶、牡丹皮以及乌梅对4种供试菌均有较强的抑制作用,采用正交试验对上述3种中草药进行复配,分析得出最佳配比为乌梅∶艾叶∶牡丹皮=8∶1∶1,在最佳配比条件下,复配抑菌剂对4种受试菌的最低抑菌浓度分别为7.81 mg/mL、3.91 mg/mL、15.62 mg/mL、7.81 mg/mL。扫描电镜的结果表明:中草药复配抑菌剂能够破坏大肠埃希氏菌细胞结构,导致细胞内容物外泄,细胞死亡。

普洱茶与绿茶提取物体外抑菌效应的研究

采用滤纸片扩散法分别研究不同浓度的普洱茶和绿茶提取物对李斯特氏菌(L.monocytogenes)、猪粪链球菌(S.faecalis)、大肠杆菌(E.coli)、鼠伤寒沙门氏菌(S.typhimurium)、金黄色葡萄球菌(S.aureus)和炭疽杆菌(B.anthracis)6株食源性微生物和致病菌的抑制效果及其最小抑菌浓度(MIC)。结果表明:普洱茶提取物在1%～7%(m/V)范围内对李斯特氏菌(L.monocytogenes)有较强的抑制作用,其MIC为0.07mg/ml,在5%～7%范围内对所有供试菌种均有抑制作用,对炭疽杆菌的抑制效果最好。绿茶提取物在1%～2%(m/V)范围内仅对李斯特氏菌(L.monocytogenes)有抑制作用,其MIC为0.09mg/ml,在3%时仅对炭疽杆菌(B.anthracis)无抑制作用,在4%～7%范围内对所有供试菌种都有抑制作用,对猪粪链球菌抑制效果最好。

艾纳香残渣不同提取部位体外抑菌活性研究

目的考察艾纳香残渣(艾渣)不同提取部位的体外抑菌活性,确定艾渣抑菌活性的有效部位。方法采用体积分数80%乙醇对艾渣中化合物进行提取得到艾渣总提取物,用适量水混悬后,依次用石油醚、三氯甲烷、乙酸乙酯、正丁醇萃取,得到不同提取部位;采用琼脂扩散法测定艾渣不同提取部位的抑菌圈直径;采用二倍稀释法测定最低抑菌浓度(MIC)及最低杀菌浓度(MBC)。结果艾渣醇提部位及石油醚、三氯甲烷、乙酸乙酯、正丁醇和水萃取部位对金黄色葡萄球菌、大肠埃希菌、肺炎克雷伯菌、白色念珠菌、铜绿假单胞菌和乙型溶血性链球菌有不同程度的抑制作用;抗菌活性部位主要为三氯甲烷萃取物,该萃取物对大肠埃希菌和乙型溶血性链球菌均有较显著的抑菌和杀菌作用,说明抑菌活性物质主要为极性较小的化合物。结论艾渣提取物具有较好的体外抗菌活性,尤以三氯甲烷萃取部位对乙型溶血性链球菌和大肠埃希菌的抑制作用显著。

狼爪瓦松全草粗提物体外抑菌作用研究

[目的]研究狼爪瓦松(Orostachys cartilaginous A.Bor)全草粗提取物体外抑菌作用。[方法]采用液-液萃取法对狼爪瓦松的体积分数为0.75的丙酮提取液的活性成分进行初步分离,制备氯仿、乙酸乙酯、正丁醇及水相萃取物。采用滤纸片法和2倍连续稀释法测定了各相萃取物对4种供试菌的体外抑菌效果。[结果]狼爪瓦松全草体积分数为0.75的丙酮提取液的各萃取相对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和普通变形杆菌有不同程度的抑菌活性,其中氯仿萃取相、乙酸乙酯萃取相对金黄色葡萄球菌显示了较好的抑菌效果,最低抑菌浓度均为1.25 mg/m l。[结论]中药狼爪瓦松全草的抑菌活性成分主要存在于氯仿萃取相和乙酸乙酯萃取相中,为狼爪瓦松抑菌药物的开发提供了理论依据。