Effect of roselle calyx extract on in vitro viability and biofilm formation ability of oral pathogenic bacteria

Objective: To investigate the effect of the roselle calyx extract(RCE)(Hibiscus sabdariffa L.) on the in vitro viability and biofilm formation ability of oral pathogenic bacteria. Methods:RCE was prepared by soaking roselle calyx powder with ethyl alcohol for 24 h at room temperature. After centrifugation, the extract was lyophilized. Then, the extract was dissolved in phosphate-buffered saline, the p H was adjusted, and the extract was aseptically filtered. We used Streptococcus mutans, Streptococcus sanguinis, Lactobacillus casei, Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia in this study. The antibacterial activity of the RCE was determined by treating the cells of these bacteria with the extract for 10 or 20 min at room temperature. The minimum inhibitory concentration(MIC) and minimum bactericidal concentration was determined using the micro dilution method, and the effect of the RCE on the ability to form biofilm was determined using a polystyrene micro plate assay. In addition, we used the WST-1 assay to determine the cytotoxicity of the RCE on HGF, Ca9-22 and KB cells. Results: The RCE had antibacterial activity against oral bacteria used in this study. In particular, most significant antibacterial activity was observed against Fusobacterium nucleatum, Prevotella intermedia and Porphyromonas gingivalis. The MIC and minimum bactericidal concentration were 7.2 mg/m L–28.8 mg/m L and 14.4 to 57.6 mg/m L. The RCE had an inhibitory effect on biofilm formation at the MIC and sub-MIC levels. In addition, the RCE had low cytotoxic effects on HGF, Ca9-22 and KB cells. Conclusions: Thus, our results indicate that the RCE may be used for preventing oral diseases.     

医院内感染病原菌回顾性调查及其耐药性研究

目的 了解我院近2年医院感染病原菌的分布及其耐药性.方法 采用回顾性调查方法,对3 944株病原菌进行统计分析.结果 革兰阳性球菌1078株,占27.3%;革兰阴性杆菌2 866株,占72.7%.产超广谱β-内酰胺酶大肠杆菌和肺炎克雷伯菌2年平均检出率分别为36.5%和27.9%.革兰阳件球菌对青霉素、苯唑西林、头孢唑啉、阿莫西林/克拉维酸、红霉素、复方新诺明、环丙沙星的2年平均耐药率达84.5%;革兰阴性杆菌对氨苄西林2年平均耐药率达96.0%,对头孢嚷肟、头孢吡肟、庆大霉素、复方新诺明、环丙沙星、氨曲南的2年平均耐药率达52.7%.结论 2年来,医院感染病原菌革兰阴性杆菌增加,革兰阳性球菌不变.细菌耐药性不断增强,临床应加强对抗菌药物使用的干预.     

2011年湘雅医院临床分离病原菌分布及耐药性分析

目的了解2011年中南大学湘雅医院临床常见分离菌的分布及耐药性,为临床合理使用抗菌药物提供依据。方法采用全自动微生物鉴定系统Vitek-2对临床分离病原菌进行鉴定及药敏试验,用WHONET5.4软件对实验结果进行分析。结果 2011年湘雅医院共分离菌株7 272株,其中革兰阳性菌2 85株,占28.67%;革兰阴性菌4 109株,占56.51%;真菌1 078株,占14.82%。葡萄菌属中耐甲氧西林金黄葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRSCN)的检出率分别为51.37%和68.16%,未检出对万古霉素、替考拉宁及利奈唑胺耐药株;屎肠球菌和粪肠球菌对万古霉素的耐药率分别均为3.91%和3.83%;大肠埃希菌和肺炎克雷伯菌中超广谱β-内酰胺酶(ESBLs)的检出率分别为78.30%和63.10%,肠杆菌科细菌对碳青霉烯类抗菌药物仍高度敏感(耐药率<6.00%),首次监测到泛耐药肠杆菌科细菌;与2010年相比,铜绿假单胞菌和鲍曼不动杆菌中泛耐药株数显著增加。结论临床分离病原菌以革兰阴性杆菌为主;分离菌株耐药性十分严重;泛耐药肠杆菌科细菌的出现及泛耐药非发酵革兰阴性杆菌的增加,应引起临床高度重视,并及时采取防控措施。     

Isolation of pathogenic microorganisms from burn patients admitted in Dhaka Medical College and Hospital and demonstration of their drug-resistance traits

ObjectiveTo isolate and quantify the microflora from the burn patients admitted in the Division of Plastic Surgery and Burns outdoor patients in Dhaka Medical College Hospital, Bangladesh.MethodsThirty wound surface swab samples of first and second degree burn patients were collected and the microbial analysis as well the study of antibacterial susceptibility was conducted. Microbial inhibitory concentration of tobramycin was tested to be applied as effective antimicrobial agent in burn patients. Activity of four disinfectants was also tested against the pathogens.ResutlsAmong all samples, 28 was found to be populated with the total viable bacteria up to 10⁷ CFU/mL. The predominant pathogen was Pseudomonas spp. followed by Staphylococcus aureus and Kebsiella spp. Three of the samples harbored Enterobacter spp. while 2 were found to be proliferated with Escherichia coli. Most of the pathogens were found to be drug-resistant while several isolates were noted to be multi-drug resistant. Dettol partly showed efficacy among the tested disinfectants to prevent pathogenic proliferation.ConclusionsHuge bacterial onset with an alarming threat of multidrug resistance would potentially raise the necessity of proper care and management of burn wound patients in hospital.     

苏南地区某二级医院近3年下呼吸道感染病原菌分布及耐药性监测

目的 调查我院近3年下呼吸道感染主要病原菌的分布与耐药情况,并以重症监护病房(ICU)与非ICU相比较,观察两者的不同之处,为临床合理选用抗菌药物提供依据.方法 使用VITEK2-compact微生物检测系统对我院下呼吸道感染住院患者的痰液标本中临床分离的941株病原菌进行细菌鉴定,采用MIC法进行药敏试验.结果 临床分离的941株细菌中,368株来自ICU,革兰阴性杆菌占85.02%(800/941).ICU与非ICU耐甲氧西林金黄色葡萄球菌(MRSA)的检出率分别为100.00%(25/25)和73.53%(25/34)(P＜0.01).病原菌中最常见的菌种依次为肺炎克雷伯菌21.15%(199/941)、铜绿假单胞菌20.30%(191/941)、鲍曼不动杆菌10.31%(97/941)、嗜麦芽窄食单胞菌7.97%(75/941)和大肠埃希菌7.44%(70/941),ICU与非ICU前5位病原菌相同,但构成比例不同.肺炎克雷伯菌和大肠埃希菌产生超广谱β-内酰胺酶(ESBL)的检出率分别为57.79%(115/199)和51.43%(36/70),ICU的ESBL检出率与非ICU比较差异具有统计学意义(P＜0.05).肺炎克雷伯菌、大肠埃希菌对亚胺培南敏感度最高,耐药率分别为5.06%和18.18%;铜绿假单胞菌对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、环丙沙星、头孢吡肟、亚胺培南、阿米卡星的耐药率在18.52%～27.66%之间;鲍曼不动杆菌耐药情况比较严重,只有对加替沙星和亚胺培南的耐药率低于30%;嗜麦芽窄食单胞菌耐药情况最严重,只对复方磺胺甲噁唑高度敏感,耐药率为9.09%,对头孢曲松、头孢噻肟、哌拉西林、阿莫西林/舒巴坦钠和亚胺培南几乎全部耐药.我院存在较高的复合感染率,为11.62%(84/723),主要发生在ICU,复合感染率及感染株数在2009年监测中明显下降.结论 革兰阴性杆菌为医院下呼吸道感染主要病原菌,且呈现多重耐药趋势.亚胺培南、头孢哌酮/舒巴坦和哌拉西林/他唑巴坦是治疗下呼吸道感染的有效药物.动态监测细菌的耐药性,合理选择抗生素,减少高危因素并制定有效的防治措施显得至关重要.     

Composition of the non-polar extracts and antimicrobial activity of Chorisia insignis HBK. leaves

ObjectiveTo investigate the chemical constituents of the petroleum ether extract and the ether fraction of the 70% ethanol extract of Chorisia insignis HBK. leaves, as well as screen its antimicrobial activity.MethodsDifferent chromatographic methods were applied to investigate the non-polar extracts and the diffusion assay method was applied to study the antimicrobial activity.ResultsA total of 50 compounds from the unsaponifiable matter and 20 fatty acid methyl esters were identified from the petroleum ether extract by GC/MS analysis. n-Hentriacontane, n-tritriacontane, stigmastanol, 3-methoxy-5, 6-dihydrostigmasterol, 7,8-dihydroergosterol, 4-methylcholesterol, cholestanol, multiflorenol, cholest-5-en-3-one, cholest-6-one, 5,6-dihydroergosterol, stigmasterol, dihydroalbigenin and 11-methyl-Δ^{5,7,9,15,17,23}-triacont-hex-ene were isolated from the petroleum ether extract. Methyl heptacosanoate and quinic acid ester of rhamnose were isolated from the ether fraction of the 70% ethanol extract. Antimicrobial activity of the total alcohol extract and the successive fractions showed that the ether and the ethyl acetate fractions have potent antibacterial activity against Bacillus subtilis and Bacillus cereus.ConclusionsThe ether and the ethyl acetate fractions could be used in pharmaceutical formulations as antibacterial agents against Bacillus subtilis and Bacillus cereus, and further clinical trials should be performed in order to support the above investigations.     

Comparative study of total phenolics,flavonoids contents and evaluation of antioxidant and antimicrobial activities of different polarities fruits crude extracts of Datura metel L.

ObjectiveTo determine the total phenolics and flavonoids and to evaluate antioxidant and antimicrobial activities of different extracts from fruits of Datura metel (D. metel).MethodsDifferent crude extracts from the fruits of D. metel were subjected to determination of total phenolics, flavonoids, antioxidant and antimicrobial activities by established methods.ResutlsThe total phenolics results showed that ethyl acetate extract was the most efficient (60.26%) compared to hexane, chloroform, butanol and methanol extracts which had phenolic contents of 50.08, 35.50, 52.54 and 26.49%, respectively. Almost similar results were obtained from the fruits crude extracts for total flavonoids and results found that methanol crude extract was the highest (1.71%) compared to other crude extracts. The antioxidant activity results showed that methanol extract acted the highest activity compared to other extracts and in the order of methanol>ethyl acetate>hexane>chloroform>butanol extract. All extracts were displayed moderate antibacterial potential against the tested bacteria such as Staphylococcus aureus, Escherichia coli and Pseudomonus aeruginosa in the range of 0%–10%.ConclusionsThe results of this present study clearly showed that the crude extracts of D. metel demenstrated antimicrobial and antioxidant activities and it may act as potential antioxidant sources for human biological system.     

In vitro studies on phytochemical evaluation and antimicrobial activity of Borassus flabellifer Linn against some human pathogens

ObjectiveTo detect preliminary phytochemicals and antimicrobial activity of seed coat of Borassus flabellifer (B. flabellifer) against some human pathogens.MethodsThe antimicrobial activity of the organic solvent extracts of seed coat of B. flabellifer against various test microorganisms including bacteria and fungi was investigated using agar well diffusion technique.ResultsThe preliminary phytochemical screening of the aqueous, methanoic and ethanolic extracts of seed coat of B. flabellifer revealed the presence of certain phytochemicals like tannins, flavonoids, saponins, glycosides and terpenoids. The zone of inhibition of methanolic extracts varied from 16 to 23 mm where as with ethanol extracts from 14 to 23 mm and aqueous extracts from 10 to 15 mm at 50 mg/mL concentrations. Among all tested organisms, Aspergillus brasiliensis and Bacillus subtilis showed a higher rate of inhibition with ethanolic and methanolic extracts of B. flabellifer.ConclusionsB. flabellifer exhibited higher rate of growth inhibition against some human pathogens, so it can be used for treatment of some infectious diseases. Further studies are being carried out to separate and purify the individual compounds that are present in seed coat of B. flabellifer by using various chromatographic techniques.     

卒中相关性肺炎:病原菌和抗生素治疗

文章从病原学、疾病和抗生素使用三方面对卒中相关性肺炎患者如何合理应用抗生素做了简要介绍.早期高度重视标准病原学检查,初始经验性治疗应及时充分,一般推荐广谱青霉素/β-内酰胺酶抑制剂的复合制剂,并在此基础上积极寻求病原学检查结果,选择针对性强或敏感的抗生素,以提高疗效,减少不良反应.     

福建省实验大鼠和小鼠常见病原菌初查

实验动物携带的各种病原菌 ,直接影响实验动物的质量和标准化 ,不同程度干扰各个领域中生命科学实验的结果 ,因而成为微生物质控的重要内容。为逐步查明本省各类实验动物病原菌的存在和分布情况。我们于 1994年首次承担实验小鼠、大鼠微生物监测的同时 ,开展病原菌普查。现将结果报告如下。1　材料与方法1 1　标本来源与采集　被检大鼠和小鼠来自本省四个单位共 51只 ,其中ＳＤ大鼠 13只 ,昆明小鼠2 1只 ,ＩＣＲ小鼠 10只 ,ＢＡＬＢ/ｃ裸小鼠 7只。鼠被毛、气管分泌物及盲肠内容物的采集方法按文献[1]进行。1 2　培养基　以Ｓａｂｏｕｒａｕ…     

Physical chemical and biological characterization of a new bacteriocin produced by Bacillus cereus NS02

ObjectiveTo screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical, chemical and biological aspects for the application in biopreservation.MethodsBacillus cereus (B. cereus) was isolated and assessed for its baceteriocinogenic activity. Bacteriocin was produced and purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography. Purified bacteriocin was used to check its antimicrobial activity against food borne bacteria. Effect and stability of bacteriocin was determined with the respect to temperature, pH, enzymes, organic solvents and chemicals. Bacteriocin was also subjected to SDS PAGE analysis to determine its molecular weight. In addition, functional groups exist in the bacteriocin was determined by FTIR analysis.ResultsB. cereus was identified by 16S rRNA sequence analysis. Bacteriocin showed increased activity against all the bacteria used and its activity unit was found to be 51, 200 AU/mL. It was stable to high temperature (100 °C) and wide range of pH (3-10), sensitive to proteolytic enzymes and resistant to nonproteolytic enzymes. It was low molecular weight (3.5 – 6 KDa) protein and FTIR study revealed the presence of amide group and NH stretching.ConclusionsBacteriocin produced in this study possesses the highest antimicrobial activity against both gram positive and gram negative bacteria thereby it has immense application as biopreservative agent. FTIR proved its peptide nature.     

基因芯片检测肠道致病菌技术的建立和应用

目的 快速、准确地检测水中存在的肠道致病菌。方法 采用基因芯片技术对水中常见肠道致病菌进行检测和鉴定，包括检测靶基冈的扩增、基因芯片的制备、杂交反应和杂交结果的检测与分析四个步骤。结果 应用基因芯片对涉及9个菌属的143株致病菌在相同的条件下进行了杂交检测，得到菌属(科)特异性的杂交图谱，从而达到对细菌进行检测鉴定的目的。结论 制备的基因芯片能够同时检测沙门菌属、志贺菌属、埃希菌属、葡萄球菌属、变形杆菌属的细菌以及小肠结肠炎耶尔森菌、副溶血性弧菌等。     

北京地区肠道致病菌的分布及耐药状况

目的 监测北京地区肠道致病菌的组成及耐药状况，为本地区的流行病学研究及临床合理用药提供依据。方法 通过常规大便培养，筛选出致病菌后经生化及血清学进一步鉴定到种，群或血清型。结果 肠道病原菌感染，以男性为主，儿童和青年发病为多，6，7月为腹泻发病高峰，病原以志贺菌属居首位，其次是弧菌，各菌属对抗生素的敏感率有差异。结论 北京地区感染性腹泻的病原种类繁多，有性别，年龄，季节的分布特点，耐药性不同，应重视监测。     

高通量测序对脓毒症病原学诊断及病原菌耐药性预测的应用价值

脓毒症是机体对感染反应失调所致的危及生命的器官功能障碍,是急危重症医学面临的重要疾病,也是临床亟待解决的难题。明确病原学后尽早针对性抗感染治疗可降低病死率,是治疗脓毒症的关键。目前的病原学检测技术在及时性和准确性等方面仍存在欠缺。高通量测序技术在诊断病原微生物方面,具有检测种类多、快速、精准等特点,且近年对于监测病原学及耐药性方面有特殊优势,并逐步应用于临床。该文就高通量测序对脓毒症病原学诊断及病原菌耐药性预测的应用价值进行综述。     

医院内下呼吸道感染患病率及病原菌分析

医院内 (院内 )下呼吸道感染 (ＮＬＲＴＩ)因病因复杂 ,病原菌多耐药 ,且常并存或合并其它疾病而使治疗困难 ,预后较差。为了解近年我院院内下呼吸道感染的发病情况 ,特进行回顾性分析。1　临床资料　　 1995～ 1997年每年 3月和 9月份住我院的病人 2 195例 ,男性 12 95例 ,女性 90 0例 ,年龄 15～ 87(5 8 2± 2 7 3)岁。2　分析方法2 1　记录每例的性别、年龄、基础疾病、所管介入操作等 ,记录手术患者麻醉方式及手术部位 ,计算各同类患者下呼吸道感染的患病率。登记培养出的致病菌种类及药敏试验结果。细菌对抗菌药的敏感率 =敏感菌株数…     

住院患者脓液及伤口分泌物的病原菌分析

目的分析住院患者脓液及伤口分泌物标本病原菌的分布及主要病原菌的耐药情况,为临床提供可靠的控制感染依据。方法对该院在2010-01～2012-12住院患者送检的1 111份脓液及3 348份伤口分泌物标本进行细菌培养,分离出的病原菌进行鉴定及药敏分析。结果分离出病原菌1 442份,细菌的分布情况为：革兰氏阳性球菌占33.9%（489/1442）,革兰氏阴性杆菌占58.3%（840/1442）,真菌占6.2%（90/1442）,检出的前几名病原菌分别为金黄色葡萄球菌占22.3%（322/1442）,大肠埃希菌占18.0%（259/1442）,铜绿假单胞菌占12.8%（185/1442）,变形杆菌占6.0%（87/1442）,不动杆菌属占6.6%（95/1442）,凝固酶阴性葡萄球菌占4.9%（70/1442）。结论该院住院患者的伤口化脓性感染主要以阴性杆菌为主,但金黄色葡萄球菌仍是感染的首要病原菌,其次是大肠埃希氏菌、铜绿假单胞菌,同时还分离出诺卡、艾肯和放线杆菌等罕见细菌。提示引起伤口化脓感染的病原菌呈现多样化,治疗应及时确定病原菌,并根据药敏结果合理用药。     

Phytochemical screening and comparative antimicrobial potential of different extracts of Stevia rebaudiana Bertoni leaves

ObjectiveTo evaluate in vitro antimicrobial potential and phytochemical screening of the crude extracts of leaves of Stevia rebaudiana Bertoni.MethodsThe essential oil and crude extracts were prepared by using different usual method. Antimicrobial and antifungal activities were measured by the well established methods.ResultsHighest antifungal index [(12.13±0.08) mm)] and lowest antifungal index [(9.13±0.04) mm] as well as highest antibacterial index [(11.89±0.07) mm] and lowest antibacterial index [(7.24±0.03) mm] were obtained for extracts B, H, A and F, respectively. Invariably extract C, E, I, J and H did not show antimicrobial activity. The extract F showed all antifungal and antibacterial activity except Bacillus cereus and Bacillus megaterium.ConclusionsThe above findings support the idea that plant extracts of Stevia rebaudiana Bertoni leaves may have a role to be used as pharmaceuticals or preservatives.